bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operando Quantification of (De)Lithiation Behavior of Silicon–Graphite Blended Electrodes for Lithium‐Ion Batteries
Authors: Yao Koffi P. C. , Okasinski John S. , Kalaga Kaushik , Almer Jonathan D. , Abraham Daniel P. 
Published: January 2019

AbstractDue to the high lithium capacity of silicon, the composite (blended) electrodes containing silicon (Si) and graphite (Gr) particles are attractive alternatives to the all‐Gr electrodes used in conventional lithium‐ion batteries. In this Communication, the lithiation and delithiation in the Si and Gr particles in a 15 wt% Si composite electrode is quantified for each component using energy dispersive X‐ray diffraction. This quantification is important as the components cycle in different potential regimes, and interpretation of cycling behavior is complicated by the potential hysteresis displayed by Si. The lithiation begins with Li alloying with Si; lithiation of Gr occurs at later stages when the potential dips below 0.2 V (all potentials are given vs Li/Li+). In the 0.2–0.01 V range, the relative lithiation of Si and Gr is ≈58% and 42%, respectively. During delithiation, Li+ ion extraction occurs preferentially from Gr in the 0.01–0.23 V range and from Si in the 0.23–1.0 V range; that is, the delithiation current is carried sequentially, first by Gr and then by Si. These trends can be used for rational selection of electrochemical cycling windows that limits volumetric expansion in Si particles, thereby extending cell life.
Atopy in chronic rhinosinusitis: impact on quality of life outcomes
Authors: Ho Jacqueline , Alvarado Raquel , Rimmer Janet , Sewell William A. , Harvey Richard J. 
Published: January 2019

BackgroundChronic rhinosinusitis (CRS), in particular with nasal polyps (CRSwNP), has been linked with skewed T‐helper 2 and immunoglobulin E (IgE)‐mediated allergic responses. The role of atopy in CRS, however, remains unclear. Correlations between immunological allergic markers and patient‐reported outcomes measures (PROMs) were investigated.MethodsA cross‐sectional study of adult patients with CRS undergoing endoscopic sinus surgery was conducted. Immunological allergic markers included automated immunoassay testing for serum‐specific IgE to common allergens (house dust mite, grass, mold, animal epithelia) and total IgE. PROMs were assessed using the 22‐item Sino‐Nasal Outcome Test (SNOT‐22). Patients were defined as atopic based on either a positive specific IgE or elevated total IgE (>160 kU/L).ResultsA total of 446 patients (45.7% female, age 49.05 ± 14.96 years) were recruited, of which 42.8% had asthma, 51.6% had CRSwNP, and 63.0% had eosinophilic CRS. Positive allergen sensitization was detected in 52.9% patients. Total IgE levels were elevated in 28.0% with mean IgE level of 161 ± 269 kU/L. Atopy was associated with younger age at the time of surgery, CRSwNP, asthma, and eosinophilic CRS (eCRS). Atopy was also associated with increased severity in nasal symptom score (13.1 ± 6.4 vs 11.9 ± 6.0, p = 0.04), as well as worse scores in the loss of smell/taste (χ2(1) = 5.97, p = 0.02) and need to blow nose (χ2(1) = 4.26, p = 0.04) questions in the CRS population. In the CRSwNP population, there was no significant association between atopy and PROMs.ConclusionComorbid atopy in CRS is associated with additional symptom burden, reflected mainly within the nasal symptom quality of life markers. Atopy assessment in CRS is important to ensure appropriate and successful treatment of the disease.
Copper‐Mediated Aminoquinoline‐Directed Radiofluorination of Aromatic C−H Bonds with K18F
Authors: Lee So Jeong , Makaravage Katarina J. , Brooks Allen F. , Scott Peter J. H. , Sanford Melanie S. 
Published: January 2019

AbstractA Cu‐mediated ortho‐C−H radiofluorination of aromatic carboxylic acids that are protected as 8‐aminoquinoline benzamides is described. The method uses K18F and is compatible with a wide range of functional groups. The reaction is showcased in the high specific activity automated synthesis of the RARβ2 agonist [18F]AC261066.
PhPAd‐DalPhos: Ligand‐Enabled, Nickel‐Catalyzed Cross‐Coupling of (Hetero)aryl Electrophiles with Bulky Primary Alkylamines
Authors: Tassone Joseph P. , England Emma V. , MacQueen Preston M. , Ferguson Michael J. , Stradiotto Mark 
Published: January 2019

AbstractThe base metal‐catalyzed C−N cross‐coupling of bulky α,α,α‐trisubstituted primary alkylamines with (hetero)aryl electrophiles represents a challenging and under‐developed class of transformations that is of significant potential utility, including in the synthesis of lipophilic active pharmaceutical ingredients. Herein, we report that a new, air‐stable Ni(II) pre‐catalyst incorporating the optimized ancillary ligand PhPAd‐DalPhos enables such transformations of (hetero)aryl chloride, bromide, and tosylate electrophiles to be carried out for the first time with substrate scope rivalling that achieved using state‐of‐the‐art Pd catalysts, including room temperature cross‐couplings of (hetero)aryl chlorides that are unprecedented for any catalyst (Pd, Ni, or other).
Total Synthesis and Anticancer Activity of (+)‐Hypercalin C and Congeners
Authors: Tao Yongfeng , Reisenauer Keighley , Taube Joseph H. , Romo Daniel 
Published: January 2019

AbstractThe hypercalins are dearomatized acylphloroglucinols with a pendant complex cyclopentane ring that exhibit activity against several cancer cell lines. We report the first total synthesis of (+)‐hypercalin C employing a convergent strategy that enabled the dissection of the essential structural features required for the observed anticancer activity. A strategic disconnection involving an unusual C
–C
Suzuki–Miyaura coupling with an α‐bromo enolether also revealed an unexpected C−H activation. This strategy targeted designed analogues along the synthetic route to address particular biological questions. These results support the hypothesis that hypercalin C may act as a proton shuttle with the dearomatized acylphloroglucinol moiety being essential for this activity.
Intermolecular Heck Coupling with Hindered Alkenes Directed by Potassium Carboxylates
Authors: Huffman Tucker R. , Wu Yebin , Emmerich Alexis , Shenvi Ryan A. 
Published: January 2019

AbstractPd0‐catalyzed Mizoroki–Heck reactions traditionally exhibit poor reactivity with polysubstituted, unbiased alkenes. Intermolecular reactions with simple, all‐carbon tetrasubstituted alkenes are unprecedented. Herein we report that pendant carboxylic acids, combined with bulky monophospine ligands on palladium, can direct the arylation of tri‐ and tetrasubstituted olefins. Quaternary carbons are established at high Fsp3 attached‐ring junctures and the carboxylate directing group can be removed after coupling. Carboxylate directivity prevents over‐arylation of the new, less substituted alkene, which can be diversified in subsequent reactions.
A Freezing‐Induced Turn‐On Imaging Modality for Real‐Time Monitoring of Cancer Cells in Cryosurgery
Authors: He Zhiyuan , Liu Pai , Zhang Shizhong , Yan Jie , Wang Mengni , Cai Zhengxu , Wang Jianjun , Dong Yuping 
Published: January 2019

AbstractCryosurgery has attracted much attention for the treatment of tumors owing to its clear advantages. However, determining the volume of frozen tissues in real‐time remains a challenge, which greatly lowers the therapeutic efficacy of cryosurgery and hinders its broad application for the treatment of cancers. Herein, we report a freezing‐induced turn‐on strategy for the selective real‐time imaging of frozen cancer cells. As a type of aggregation‐induced emission (AIE) fluorogen, TABD‐Py molecules interact specifically with ice crystals and form aggregates at the ice/water interface. Consequently, bright fluorescent emission appears upon freezing. TABD‐Py molecules are enriched mostly in the cancer cells and exhibit high biocompatibility as well as low cytotoxicity; therefore, a freezing‐induced turn‐on imaging modality for cryosurgery is developed, which will certainly maximize the therapeutic efficacy of cryosurgery in treating tumors.
RhIAr/AuIAr′ Transmetalation: A Case of Group Exchange Pivoting on the Formation of M−M′ Bonds through Oxidative Insertion
Authors: Peñas‐Defrutos Marconi N. , Bartolomé Camino , García‐Melchor Max , Espinet Pablo 
Published: January 2019

AbstractBy combining kinetic experiments, theoretical calculations, and microkinetic modeling, we show that Pf/Rf (C6F5/C6Cl2F3) exchange between [AuPf(AsPh3)] and trans‐[RhRf(CO)(AsPh3)2] does not occur by typical concerted Pf/Rf transmetalation via electron‐deficient double bridges. Instead, it involves asymmetric oxidative insertion of the RhI complex into the (Ph3As)Au−Pf bond to produce a [(Ph3As)Au−RhPfRf(CO)(AsPh3)2] intermediate, followed by isomerization and reductive elimination of [AuRf(AsPh3)]. Interesting differences were found between the LAu−Ar asymmetric oxidative insertion and the classical oxidative addition process of H2 to Vaska complexes.
Katalyse mit durch sichtbares Licht angeregten Palladiumkomplexen
Authors: Chuentragool Padon , Kurandina Daria , Gevorgyan Vladimir 
Published: January 2019

AbstractDurch sichtbares Licht induzierte Palladiumkatalyse ist ein aufstrebendes Teilgebiet der Katalyse. Im Unterschied zu klassischen, durch Pd‐Komplexe im Grundzustand katalysierten Reaktionen, die vornehmlich durch Zweielektronen‐Redoxprozesse voranschreiten, laufen die Mechanismen der neuartigen Reaktionen auf Basis photoangeregter Pd‐Komplexe meist durch die Übertragung eines einzelnen Elektrons ab. Diese Prozesse führen mutmaßlich zu hybriden Pd/Radikal‐Spezies, die sowohl die Reaktivität von Radikalen als auch die von klassischen Pd‐Spezies aufweisen. Dieser Kurzaufsatz beleuchtet aktuelle Fortschritte auf diesem schnell wachsenden Gebiet.
Electrochemical‐Conditioning‐Free and Water‐Resistant Hybrid AlCl3/MgCl2/Mg(TFSI)2 Electrolytes for Rechargeable Magnesium Batteries
Authors: He Yishi , Li Qi , Yang Lanlan , Yang Chaoran , Xu Dongsheng 
Published: January 2019

AbstractRechargeable magnesium batteries are a promising alternative to Li‐based energy storage because of their abundant and inexpensive components. The high sensitivity and reactivity of the organic Mg2+ electrolyte makes their development challenging. Herein, we develop a new hybrid electrolyte, based on three simple inorganic salts of MgCl2, AlCl3, and Mg(TFSI)2. The electrolyte exhibits unprecedented electrochemical performance for reversible deposition and stripping of Mg, with Coulombic efficiency up to 97 %, overpotential down to 0.10 V, good stability especially for aluminum and stainless‐steel current collectors. It maintained its activity even after introducing 2000 ppm water and it could be prepared from impure chemicals. A full cell with the hybrid electrolyte and Mg foil as anode, Mo6S8 as cathode gave a specific capacity of 98 mAh g−1 and maintained 94 % capacity after 100 cycles at a rate of 0.20 C, indicating the good compatibility of the hybrid electrolyte.
Novel aluminium compounds derived from Schiff bases: Synthesis, characterization and catalytic performance in hydroboration
Authors: Jin Da , Ma Xiaoli , Liu Yashuai , Peng Jiong , Yang Zhi 
Published: January 2019

Seven novel aluminium complexes supported by Schiff base ligands derived from o‐diaminobenzene or o‐aminothiophenol were synthesized and characterized. The reactions of AlMe3 with L1 (N,N′‐bis(benzylidine)‐o‐phenylenediamine) and L2 (N,N′‐bis(2‐thienylmethylene)‐o‐phenylenediamine) gave the complexes L1AlMe3 (1) and L2AlMe2 (2), respectively, which involved two types of reaction mechanisms: one was proton transfer and ring closure, and the other was alkyl transfer. Complexes L3AlMe2 (HL3 = 4‐chlorobenzylidene‐o‐aminothiophenol) (3), L4AlMe2 (HL4 = 2‐thiophenecarboxaldehyde‐o‐aminothiophenol) (4), L3AlH(NMe3) (5), L4AlH(NMe3) (6) and L5AlH(NMe3) (HL5 = 4‐methylbenzylidene‐o‐aminothiophenol) (7) were prepared by reacting HL3–5 with equimolar AlMe3 or H3Al⋅NMe3, respectively. Compounds 3–7 feature an organic–inorganic hybrid containing CNAlSC five‐membered ring. All complexes were characterized using 1H NMR and 13C NMR spectroscopy, X‐ray crystal structure analysis and elemental analysis. The efficient catalytic performances of 1–7 for the hydroboration of carbonyl groups were investigated, with compound 4 exhibiting the highest catalytic activity among all the complexes.
Synthesis and characterization of bio‐based benzoxazines derived from thymol
Authors: Dogan Yelda Ertas , Satilmis Bekir , Uyar Tamer 
Published: January 2019

ABSTRACTIn the present study, bio‐based benzoxazine resins were synthesized from bio‐based phenolic compound; thymol, and three different amines; ethylamine, aniline and 1,6‐diaminohexane, and paraformaldehyde by solvent‐free condensation reaction. The chemical structures of bio‐based benzoxazines; T‐ea (thymol, ethylamine), T‐a (thymol, aniline), and T‐dh (thymol, 1,6‐diaminohexane) were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, elemental analysis, and high‐resolution mass spectrometry. The curing studies of T‐ea, T‐a, and T‐dh bio‐based benzoxazines were performed by stepwise thermal treatment at 150, 175, 200, 225, and 250 °C. The polymerization (ring‐opening and crosslinking reactions) of T‐ea, T‐a, and T‐dh bio‐based benzoxazines was investigated by FTIR spectroscopy. Cure analysis was conducted using differential scanning calorimetry and the changes in thermal properties of the T‐ea, T‐a, and T‐dh bio‐based benzoxazine resins and their corresponding thermally crosslinked polybenzoxazines PT‐ea, PT‐a, and PT‐dh were studied by thermogravimetric analyzer. The results indicated that all the thymol‐based polybenzoxazines have shown enhanced thermal stability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47371.
NixCo3‐xO4 Nanoneedle Arrays Grown on Ni Foam as an Efficient Bifunctional Electrocatalyst for Full Water Splitting
Authors: Bao Jian , Liu Wenjun , Xie Junfeng , Xu Li , Guan Meili , Lei Fengcai , Zhao Yan , Huang Yunpeng , Xia Jiexiang , Li Huaming 
Published: January 2019

AbstractDeveloping highly active, stable and robust electrocatalysts based on earth‐abundant elements for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is important for many renewable energy conversion processes. Herein, NixCo3‐xO4 nanoneedle arrays grown on 3D porous nickel foam (NF) was synthesized as a bifunctional electrocatalyst with OER and HER activity for full water splitting. Benefiting from the advantageous structure, the composite exhibits superior OER activity with an overpotential of 320 mV achieving the current density of 10 mA cm−2. An exceptional HER activity is also acquired with an overpotential of 170 mV at the current density of 10 mA cm−2. Furthermore, the catalyst also shows the superior activity and stability for 20 h when used in the overall water splitting cell. Thus, the hierarchical 3D structure composed of the 1D nanoneedle structure in NixCo3‐xO4/NF represents an avenue to design and develop highly active and bifunctional electrocatalysts for promising energy conversion.
X‐Shaped Polycyclic Aromatic Hydrocarbons: Optical Properties and Tunable Assembly Ability
Authors: Li Yongjun , Zhou Weixiang , Shen Han , Gu Yanan , Li Yuliang 
Published: January 2019

AbstractAlthough a number of synthetic methodologies have been developed to prepare stable polycyclic aromatic hydrocarbons (PAHs), much less research has been devoted to functionalizing the peripheries of molecules to tune the self‐assembly ability or introduce functional groups without altering their photophysical properties. Herein, we report twisted “X”‐shaped molecules prepared through annulation of hexacene with benzoanthracene on the zigzag edge, and an investigation of their photophysical properties and self‐assembly properties. The shape‐complementary “X”‐shaped molecules prefer to dimerize, while the π‐extension would lead to one‐dimensional π‐stacking. Our findings give some insights into the design of stable PAHs without disturbing the electronic structures.
The PROTAC technology in drug development
Authors: Zou Yutian , Ma Danhui , Wang Yinyin 
Published: January 2019

Currently, a new technology termed PROTAC, proteolysis targeting chimera, has been developed for inducing the protein degradation by a targeting molecule. This technology takes advantage of a moiety of targeted protein and a moiety of recognizing E3 ubiquitin ligase and produces a hybrid molecule to specifically knock down a targeted protein. During the first decade, three pedigreed groups worked on the development of this technology. To date, this technology has been extended by different groups, aiming to develop new drugs against different diseases including cancers. This review summarizes the contributions of the groups for the development of PROTAC.Significance of the studyThis review summarized the development of the PROTAC technology for readers and also presented the author's opinions on the application of the technology in tumor therapy.
A Metal‐Doped Fungi‐Based Biomaterial for Advanced Electrocatalysis
Authors: Krejčová Ludmila , Leonhardt Terza , Novotný Filip , Bartůněk Vilém , Mazánek Vlastimil , Sedmidubský David , Sofer Zdeněk , Pumera Martin 
Published: January 2019

AbstractNature and its highly sophisticated biomaterials are an endless source of inspiration for engineers and scientists across a wide range of disciplines. During the last decade, concepts of bioinspired synthesis of hierarchically structured nano‐ and micromaterials have been attracting increasing attention. In this article, we have utilized the natural ability of fungi to absorb metal ions for a bioinspired synthesis of carbonaceous material doped by selected transition metals. As an all‐around metal accumulator, Hebeloma mesophaeum was selected, and it was cultivated in the presence of three transition‐metal ions: NiII, FeII, and MnII. The metal‐doped carbonized biomaterial possessed enhanced catalytic activity toward hydrazine oxidation, oxygen reduction, and cumene hydroperoxide reduction. Thus, we have shown possible transformation of a waste product (fungi grown on a contaminated soil) into a value‐added carbonaceous material with tailored catalytic properties. This bioinspired synthesis can outline an attractive route for the fabrication of catalysts for important industrial applications on a large scale.
Difluorodiazoethane (CF2HCHN2): A New Reagent for the Introduction of the Difluoromethyl Group
Authors: Mykhailiuk Pavel K. , Koenigs Rene M. 
Published: January 2019

AbstractDifluorodiazoethane (CF2HCHN2) is a small reactive diazoalkane. Its synthesis has been pursued since the 1970s, although only in the past three years have considerable advances been made. Today, difluorodiazoethane is a versatile reagent applied in [3+2]‐cycloadditions, esterification, and carbene transfer reactions. Difluorodiazoethane possesses markedly altered reactivity compared to the well‐studied trifluorodiazoethane (CF3CHN2). In this article, we discuss the differences between the two reagents: CF2HCHN2 and CF3CHN2. We highlight applications of difluorodiazoethane in organic synthesis, discuss bench‐stable analogues, and its unexplored areas.
Understanding Silica from the Viewpoint of Asymmetry
Authors: Jin Ren‐Hua 
Published: January 2019

AbstractSilica is abundant in the Earth's crust, and silicate materials are used on the global scale, from industrial products for architecture, vehicles, electronics, and optics to consumption as foods, medicines, supplements, and cosmetics. Silica has become increasingly important in current science and technology, as seen in the components of advanced materials. The characteristic formula of silica is very simply often expressed as SiO2. However, it is difficult to draw silica precisely owing to its intricate chemical structures. We need to make a greater effort in understanding silica, even though silica chemistry has existed for over 200 years. Similar to the homochirality observed in natural amino acids, natural silica of quartz is chiral, and in some sense, the origin of life with chirality might be partly related to quartz‐like silica chirality. This review focuses on the asymmetry of silica from the view of the formation of irregular tetrahedron structures of SiO4. Silica is composed of several repeated tetrahedron units of SiO4, leading to the formation of inorganic polymers with divergently expanded 3D structures. In this large polymeric skeleton, not every unit of SiO4 can maintain an ideal tetrahedron, and thus, it becomes twisted. The twisting results in an asymmetric point on the Si atom, leading silica to become racemic in the stereochemical sense. Therefore, enantioselective preparation of silica should endow silica with chirality through the silica skeleton. Some recent achievements exhibit that silica is an effective chiral material and has great potential for transferring chirality from silica to other matter.
Fluorogenic Detection and Characterization of Proteins by Aggregation‐Induced Emission Methods
Authors: Xie Sheng , Wong Alex Y. H. , Chen Sijie , Tang Ben Zhong 
Published: January 2019

AbstractProtein is one of the four most important biomacromolecules in living systems. The detection, quantification, localization, and characterization of proteins is essential for an understanding of biological fundamentals, as well as for the diagnostics and treatment of protein‐related diseases. By using intrinsic and extrinsic fluorescence, different techniques have been established to study proteins, many of which are now being routinely used in research laboratories and clinics. This review summarizes the applications of aggregation‐induced emission (AIE) fluorescence in protein science. In contrast to traditional fluorescent dyes, the activation of AIE dyes is mainly attributed to the restriction of intramolecular motions. This unique turn‐on mechanism of AIE dyes allows researchers to develop novel fluorogenic strategies for sensitive, selective, and reliable analysis of proteins. This review focuses on introducing AIE strategies for 1) detection, localization, and quantification of proteins; 2) probing polymer conformational transitions of proteins; 3) characterization of protein–ligand interactions; and 4) evaluation of enzyme activities. Perspectives and challenges with respect to this emerging field of protein characterization are offered.
Stereochemical Insights into the Anaerobic Degradation of 4‐Isopropylbenzoyl‐CoA in the Denitrifying Bacterium Strain pCyN1
Authors: Küppers Julian , Becker Patrick , Jarling René , Dörries Marvin , Cakić Nevenka , Schmidtmann Marc , Christoffers Jens , Rabus Ralf , Wilkes Heinz 
Published: January 2019

AbstractThe constitutions and absolute configurations of two previously unknown intermediates, (1S,2S,4S)‐2‐hydroxy‐4‐isopropylcyclohexane‐1‐carboxylate and (S)‐3‐isopropylpimelate, of anaerobic degradation of p‐cymene in the bacterium Aromatoleum aromaticum pCyN1 are reported. These intermediates (as CoA esters) are involved in the further degradation of 4‐isopropylbenzoyl‐CoA formed by methyl group hydroxylation and subsequent oxidation of p‐cymene. Proteogenomics indicated 4‐isopropylbenzoyl‐CoA degradation involves (i) a novel member of class I benzoyl‐CoA reductase (BCR) as known from Thauera aromatica K172 and (ii) a modified β‐oxidation pathway yielding 3‐isopropylpimeloyl‐CoA analogously to benzoyl‐CoA degradation in Rhodopseudomonas palustris. Reference standards of all four diastereoisomers of 2‐hydroxy‐4‐isopropylcyclohexane‐1‐carboxylate as well as both enantiomers of 3‐isopropylpimelate were obtained by stereoselective syntheses via methyl 4‐isopropyl‐2‐oxocyclohexane‐1‐carboxylate. The stereogenic center carrying the isopropyl group was established using a rhodium‐catalyzed asymmetric conjugate addition. X‐ray crystallography revealed that the thermodynamically most stable stereoisomer of 2‐hydroxy‐4‐isopropylcyclohexane‐1‐carboxylate is formed during p‐cymene degradation. Our findings imply that the reductive dearomatization of 4‐isopropylbenzoyl‐CoA by the BCR of A. aromaticum pCyN1 stereospecifically forms (S)‐4‐isopropyl‐1,5‐cyclohexadiene‐1‐carbonyl‐CoA.