bluuebunny/crossref_metadata_2025 huggingface dataset:
Transitional Metal‐Based Noncatalytic Medicine for Tumor Therapy
Authors: Wu Wencheng , Pu Yinying , Lu Xiangyu , Lin Han , Shi Jianlin
Published: April 2021

Nanocatalytic medicine has been emerging as a highly promising strategy for cancer therapeutics since it enables tumor suppression by in situ generating toxic agents within tumors through catalytic reactions without using conventional highly toxic and nonselective chemodrugs. In the last several years, a number of nanocatalytic medicines have been used to steer catalytic reactions in endogenous or exogenous stimuli‐activated cancer therapy, such as chemodynamic therapy, photodynamic therapy, and sonodynamic therapy. In particular, transitional metal‐based nanocatalytic medicines with excellent catalytic activity and selectivity show significant clinical potentials, and significant progress has been achieved very recently. In this review, three types of typical transitional metal (Fe, Mn, and Cu)‐based nanocatalytic medicines are summarized, followed by detailed discussions on their catalytic mechanisms. Of note, the obstacles and challenges that will be encountered in the design and further clinical conversion of transitional metal‐based nanocatalytic medicine in the future are also outlooked.
Effective [3+1+1+1] Cycloaddition to Six‐Membered Carbocycle Based on DMSO as Dual Carbon Synthon
Authors: Li Hui , Su Miaodong , Nie Zhiwen , Yang Tonglin , Luo Weiping , Liu Qiang , Guo Cancheng
Published: April 2021

A [3+1+1+1] cycloaddition was developed among 2‐arylpropene, ketone and DMSO in the presence of K2S2O8. 2‐arylpropene provides three carbons, ketone offers one carbon, and DMSO as dual carbon donor contributes two carbons to the six‐membered carbocycle. It gave the cyclohexene motif and spirocyclohexene skeleton. Four C−C bonds formed in this process. Both propylene and ketone could be well tolerated and give the corresponding cyclohexene or spirocyclohexene motif in useful yields. Based on the controlled experiments, a possible mechanism was proposed.

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Catalyst‐ and Substrate‐Dependent Chemodivergent Reactivity of Stabilised Sulfur Ylides with Salicylaldehydes
Authors: Denisa Bisag Giorgiana , Ruggieri Silvia , Fochi Mariafrancesca , Bernardi Luca
Published: April 2021

Stabilised sulfur ylides are synthetically appealing compounds, which reactivity under Brønsted acid catalysis has been poorly explored. Herein, we report a new catalyst‐ and substrate‐ dependent chemodivergent reaction between stabilised sulfur ylides and salicylaldehydes, leading to the (suprising) formation of 2H‐chromenes or dihydrobenzofurans products. Particular attention was set on the unusual mechanisms involved. Two unique reaction routes including two ylide units in the reactions are proposed. These pathways were validated by performing a selectivity switch in some cases, enabled by the modulation of the nucleophilicity of the sulfur ylide, and by the loading of the Brønsted acid catalyst in the reaction.

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Chemo‐ and Site‐Selective Fischer Esterification Catalyzed by B(C6F5)3
Authors: Li Ya‐Lan , Pang Jin‐Yu , Lou Ji‐Cong , Sun Wen‐Wu , Liu Ji‐Kai , Wu Bin
Published: April 2021

A direct and catalytic dehydrative esterification of carboxylic acids with alcohols is described. B(C6F5)3 is shown to be a highly effective catalyst for the Fischer esterification, providing esters in high to excellent yields. This esterification shows excellent chemo‐ and site‐selective monoesterification of various polyols without any protection step, including bio‐derived molecule glycerol.
Superficial Siderosis: A Clinical Review
Authors: Kumar Neeraj
Published: April 2021

Superficial siderosis of the central nervous system results from subpial hemosiderin deposition due to chronic low‐grade bleeding into the subarachnoid space. The confluent and marginal subpial hemosiderin is best appreciated on iron‐sensitive magnetic resonance imaging sequences. With widespread use of magnetic resonance imaging, the disorder is increasingly being recognized, including in asymptomatic individuals. Gait ataxia, often with hearing impairment is a common clinical presentation. A clinical history of subarachnoid hemorrhage is generally not present. A macrovascular pathology is generally not causative. The most common etiology is dural disease, often dural tears. Prior or less commonly ongoing symptoms of craniospinal hypovolemia may be present. Common etiologies for dural tears include disc disease and trauma, including surgical trauma. Patients with dural tears due to herniated and calcified discs often have a ventral intraspinal fluid collection due to cerebrospinal fluid leak. A precise identification of the dural tear relies on multimodality imaging. It has been speculated that chronic bleeding from fragile blood vessels around the dural tear may be the likely underlying mechanism. Surgical correction of the bleeding source is a logical therapeutic strategy. Clinical outcomes are variable, although neuroimaging evidence of successful dural tear repair is noted. The currently available data regarding use of deferiprone in patients with superficial siderosis is insufficient to recommend its routine use in patients. ANN NEUROL 2021;89:1068–1079
Thermosensitive Vesicles from Chemically Encoded Lipid‐Grafted Elastin‐like Polypeptides
Authors: Ibrahimova Vusala , Zhao Hang , Ibarboure Emmanuel , Garanger Elisabeth , Lecommandoux Sébastien
Published: April 2021

Biomimetic design to afford smart functional biomaterials with exquisite properties represents synthetic challenges and provides unique perspectives. In this context, elastin‐like polypeptides (ELPs) recently became highly attractive building blocks in the development of lipoprotein‐based membranes. In addition to the bioengineered post‐translational modifications of genetically encoded recombinant ELPs developed so far, we report here a simple and versatile method to design biohybrid brush‐like lipid‐grafted‐ELPs using chemical post‐modification reactions. We have explored a combination of methionine alkylation and click chemistry to create a new class of hybrid lipoprotein mimics. Our design allowed the formation of biomimetic vesicles with controlled permeability, correlated to the temperature‐responsiveness of ELPs.
Single Fluorinated Agent for Multiplexed 19F‐MRI with Micromolar Detectability Based on Dynamic Exchange
Authors: Shusterman‐Krush Ronit , Tirukoti Nishanth D. , Bandela Anil Kumar , Avram Liat , Allouche‐Arnon Hyla , Cai Xiaoyang , Gibb Bruce C. , Bar‐Shir Amnon
Published: April 2021

The weak thermal polarization of nuclear spins limits the sensitivity of MRI, even for MR‐sensitive nuclei as fluorine‐19. Therefore, despite being the source of inspiration for the development of background‐free MRI for various applications, including for multiplexed imaging, the inability to map very low concentrations of targets using 19F‐MRI raises the need to further enhance this platform's capabilities. Here, we employ the principles of CEST‐MRI in 19F‐MRI to obtain a 900‐fold signal amplification of a biocompatible fluorinated agent, which can be presented in a “multicolor” fashion. Capitalizing on the dynamic interactions in host–guest supramolecular assemblies in an approach termed GEST, we demonstrate that an inhalable fluorinated anesthetic can be used as a single 19F‐probe for the concurrent detection of micromolar levels of two targets, with potential in vivo translatability. Further extending GEST with new designs could expand the applicability of 19F‐MRI to the mapping of targets that have so‐far remained non‐detectable.
Catalytic Oxygenation of Hydrocarbons by Mono‐μ‐oxo Dicopper(II) Species Resulting from O−O Cleavage of Tetranuclear CuI/CuII Peroxo Complexes
Authors: Jurgeleit Ramona , Grimm‐Lebsanft Benjamin , Flöser Benedikt Maria , Teubner Melissa , Buchenau Sören , Senft Laura , Hoffmann Jonas , Naumova Maria , Näther Christian , Ivanović‐Burmazović Ivana , Rübhausen Michael , Tuczek Felix
Published: April 2021

One of the challenges of catalysis is the transformation of inert C−H bonds to useful products. Copper‐containing monooxygenases play an important role in this regard. Here we show that low‐temperature oxygenation of dinuclear copper(I) complexes leads to unusual tetranuclear, mixed‐valent μ4‐peroxo [CuI/CuII]2 complexes. These Cu4O2 intermediates promote irreversible and thermally activated O−O bond homolysis, generating Cu2O complexes that catalyze strongly exergonic H‐atom abstraction from hydrocarbons, coupled to O‐transfer. The Cu2O species can also be produced with N2O, demonstrating their capability for small‐molecule activation. The binding and cleavage of O2 leading to the primary Cu4O2 intermediate and the Cu2O complexes, respectively, is elucidated with a range of solution spectroscopic methods and mass spectrometry. The unique reactivities of these species establish an unprecedented, 100 % atom‐economic scenario for the catalytic, copper‐mediated monooxygenation of organic substrates, employing both O‐atoms of O2.
Expedient Dual Co/Organophotoredox Catalyzed Stereoselective Synthesis of All‐Carbon Quaternary Centers
Authors: Cristòfol Àlex , Limburg Bart , Kleij Arjan W.
Published: April 2021

An efficient and attractive Co/organophotoredox dual catalysis protocol has been developed allowing the stereoselective access to a wide variety of syn‐configured 1,3‐diols featuring quaternary carbon centers. The synthesis of the target molecules is achieved under ambient reaction conditions using modular and accessible reagents, substituted vinyl cyclic carbonates and aldehydes, and in short reaction times. Mechanistic control experiments suggest that the stereoselectivity can be rationalized via a preferred Zimmerman–Traxler transition state comprising a Co(allyl) species and an activated aldehyde. This newly developed process thus expands the use of base metal catalysis in the construction of challenging quaternary carbon stereocenters.
Observation of Borane–Olefin Proximity Interaction Governing the Structure and Reactivity of Boron‐Containing Macrocycles
Authors: Murata Yukihiro , Matsunagi Kenta , Kashida Junki , Shoji Yoshiaki , Özen Cihan , Maeda Satoshi , Fukushima Takanori
Published: April 2021

While attractive interactions between borane and olefin have been postulated to trigger various boron‐mediated organic transformations, proximity structures of these functional groups, other than the formation of weak van der Waals complexes, have never been directly observed. Here we show that a close intramolecular borane–olefin interaction operates in macrocyclic systems containing borane and olefinic groups obtained by multi‐step 1,2‐carboboration between a strained alkyne and 9‐borafluorene derivatives. Depending on Lewis acidity of the borane moiety and the size of the macrocycles, the magnitude of interaction changes, resulting in different reaction modes. The whole picture of the multi‐step reactions has been revealed experimentally with theoretical supports. The present finding may not only provide a deeper understanding of the fundamental boron‐mediated interaction but also lead to the development of new organic transformations involving molecular activation by boranes.
Response to “What Shall We Do with Computed Detonation Performance? Comment on ‘1,3,4‐Oxadiazole Bridges: A Strategy to Improve Energetics at the Molecular Level’”
Authors: Ma Jinchao , Chinnam Ajay Kumar , Cheng Guangbin , Yang Hongwei , Zhang Jiaheng , Shreeve Jean'ne M.
Published: April 2021

The values obtained for detonation performance are a function of the computational methods utilized. Since there are many such methods, the literature may contain a range of values for a single compound.
Biodiesel production from milk thistle seed oil as nonedible oil by cosolvent esterification–transesterification process
Authors: Saeed Liqaa I. , Khalaf Ahmed M. , Fadhil Abdelrahman B.
Published: April 2021

The crude oil extracted from milk thistle seeds was employed as a precursor for creating biodiesel (BD) via the cosolvent esterification–transesterification process. The high acid value of the extracted oil (11.90 mg KOH/g) encouraged its pre‐esterification in the occurrence of hexane as a cosolvent. The cosolvent esterification of oil diminished its acidity index to below 2.0 mg KOH/g using 1.5:1 hexane:methanol volume ratio, 50°C, 60‐min reaction time, 6:1 methanol:oil molar ratio, and 0.75 wt.% HCl. Alcoholysis reaction of the esterified oil with methanol and a blend of methanol:ethanol to synthesize, respectively, methylic BD and methylic/ethylic BD was accomplished in the presence of hexane as a cosolvent as well. Under the ideal reaction conditions, methylic BD yield and methylic/ethylic BD yield were 96.23% and 95.63%, respectively. The Fourier‐transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectra affirmed the lipid transformation from milk thistle seeds into BD. The attained samples of BD exhibited properties conforming to those specified by ASTM D6751. Also, the cosolvent methanolysis kinetic obeyed the pseudo‐first‐order with 35.94 KJ/mol activation energy and 6.32‐s frequency factor.
Characterization and antimicrobial properties of ferulic acid grafted self‐assembled bacterial cellulose‐chitosan membranes
Authors: Shen Runyan , Wang Haijun , Wu Kaizhang , Gao Jie , Li Jianbin
Published: April 2021

Bacterial cellulose (BC) is a biomaterial with many excellent properties, but its application as a food packaging and biomedical material is limited due to its lack of antibacterial properties. In this study, ferulic acid (FA) grafted self‐assembled bacterial cellulose‐chitosan (BCF) membranes were prepared by soaking BC films in chitosan‐ferulic acid (CF) solution to synthesize antibacterial biomaterials. 1H NMR confirmed that FA grafted onto chitosan successfully. The results of field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and tensile analysis showed that CF were successfully incorporated into BC matrix and the BCF membranes had good physical properties. The antibacterial experiments demonstrated that BCF membranes had an excellent antibacterial effect against Staphylococcus aureus and Escherichia coli. Therefore, combining all these properties, BCF composite membranes would have potential application in food packaging or wound‐healing materials.
Polyoxometalates/polymer composites for the photodegradation of bisphenol‐A
Authors: Brahmi Chaima , Benltifa Mahmoud , Ghali Mariem , Dumur Frédéric , Simonnet‐Jégat Corine , Monnier Valérie , Morlet‐Savary Fabrice , Bousselmi Latifa , Lalevée Jacques
Published: April 2021

Nowadays water scarcity represents a threat for human and living beings. Therefore, to satisfy the demands of people for clean and safe water, new technologies for wastewater treatment have been developed. Thus, photocatalysis has emerged as a green chemical approach for such treatment. In this context, new polyoxometalate (POM)/polymer composites with relevant photocatalytic properties have been developed via an easy and cheap photopolymerization process upon mild visible light irradiation at 405 nm. This fruitful association between POM and polymer allowed the obtention of shaped materials facile to collect and reuse at the end of the photocatalytic treatment avoiding then the usual time‐consuming regeneration methods. The prepared photocomposites displayed excellent photocatalytic performance for the removal of bisphenol‐A from water under different sources of irradiation. Hence, 100%, 88%, and 50% of this model compound were decomposed by the phosphomolybdic composite under just 90 min of UV lamp, solar and LED@375 nm irradiations, respectively. The effectiveness of these developed photocatalysts towards the degradation of other organic compounds, as well as the degradation mechanism based on the generation of highly reactive chemicals such as •OH radicals promoting the degradation were already reported. Bisphenol‐A degradation pathway and the identification of the photoproducts were discussed using mass spectroscopy technique. Therefore, this paper highlighted the photocatalytic efficiency of the new manufactured materials for the photodegradation of the bisphenol‐A, thus expanding their application fields, under different sources of irradiation and under pure solar irradiation which make their applications more interesting and less energy consuming.
Results on controllability of Hilfer fractional differential equations with infinite delay via measures of noncompactness
Authors: Kavitha K. , Vijayakumar V. , Udhayakumar R. , Ravichandran C.
Published: April 2021

This manuscript mainly focuses on the controllability of Hilfer fractional differential system with infinite delay. We study our primary outcomes by employing fractional calculus, measures of noncompactness, and fixed‐point approach. Then, we extend our results to the concept of nonlocal conditions. Lastly, an example is given for illustration of theory.
Heterogeneous Solid‐Electrolyte Interphase in Graphite Electrodes Assessed by 4D‐Resolved Computational Simulations
Authors: Chouchane Mehdi , Arcelus Oier , Franco Alejandro A.
Published: April 2021

Graphite is one of the most used active materials in lithium‐ion battery negative electrodes thanks to its high specific capacity and low equilibrium potential. For over 40 years, one of the most discussed issues with this material revolves around the complex formation mechanism of the solid‐electrolyte interphase (SEI), which acts as a protective layer against electrolyte decomposition but causes capacity losses. Due to the difficulties to experimentally observe the SEI (air sensibility, low contrast and nanometric size), its impact on the performance of graphite‐based porous electrodes has never been spatially assessed in regards of the three‐dimensional features of the electrodes. We report here a new 4D (3D+time) resolved computational model which gives insights about the SEI heterogeneity within such porous electrodes. The model is applied to different graphite morphologies and is able to assess the electrode mesostructure impact on the SEI formation and the impact of the latter on the electrodes’ electrochemical performance. This work paves the way towards a powerful tool to assist in the interpretation of SEI characterization experiments.
Can ketone bodies inactivate coronavirus spike protein? The potential of biocidal agents against SARS‐CoV‐2
Authors: Shaheen Alaa
Published: April 2021

Biocidal agents such as formaldehyde and glutaraldehyde are able to inactivate several coronaviruses including SARS‐CoV‐2. In this article, an insight into one mechanism for the inactivation of these viruses by those two agents is presented, based on analysis of previous observations during electron microscopic examination of several members of the orthocoronavirinae subfamily, including the new virus SARS‐CoV‐2. This inactivation is proposed to occur through Schiff base reaction‐induced conformational changes in the spike glycoprotein leading to its disruption or breakage, which can prevent binding of the virus to cellular receptors. Also, a new prophylactic and therapeutic measure against SARS‐CoV‐2 using acetoacetate is proposed, suggesting that it could similarly break the viral spike through Schiff base reaction with lysines of the spike protein. This measure needs to be confirmed experimentally before consideration. In addition, a new line of research is proposed to help find a broad‐spectrum antivirus against several members of this subfamily.
Ultrafast dynamics on fluorescence quenching of rhodamine 6G by graphene oxide
Authors: Liu Dunli , Wang Qiuyun , Chen Anmin , Li Qingyi , Sui Laizhi , Jin Mingxing
Published: April 2021

Fluorescence quenching of rhodamine 6G by graphene oxide (GO) was investigated using steady‐state fluorescence spectroscopy and ultrafast time‐resolved absorption spectroscopy. The steady‐state fluorescence spectra showed that rhodamine 6G fluorescence was effectively quenched by titrating the GO to the rhodamine 6G solutions. For lower GO concentrations, transient dynamic curves followed two‐exponential decay parameters. For higher GO concentrations, the dynamic curves could not be fitted well, and three‐exponential decay parameters were appropriate. The results indicated that there was a new transition process (electron transfer) in the exited rhodamine 6G and GO solution.
Telocytes of the male urogenital system: Interrelationships, possible functions, and pathological implications
Authors: Sanches Bruno Domingos Azevedo , Tamarindo Guilherme Henrique , Maldarine Juliana Dos Santos , Da Silva Alana Della Torre , Dos Santos Vitória Alário , Góes Rejane Maira , Taboga Sebastião Roberto , Carvalho Hernandes F.
Published: April 2021

The male urogenital system is composed of the reproductive system and the urinary tract; they have an interconnected embryonic development and share one of their anatomical components, the urethra. This system has a highly complex physiology deeply interconnected with the circulatory and nervous systems, as well as being capable of adapting to environmental variations; it also undergoes changes with aging and, in the case of the reproductive system, with seasonality. The stroma is an essential component in this physiological plasticity and its complexity has increased with the description in the last decade of a new cell type, the telocyte. Several studies have demonstrated the presence of telocytes in the organs of the male urogenital system and other systems; however, their exact function is not yet known. The present review addresses current knowledge about telocytes in the urogenital system in terms of their locations, interrelationships, possible functions and pathological implications. It has been found that telocytes in the urogenital system possibly have a leading role in stromal tissue organization/maintenance, in addition to participation in stem cell niches and an association with the immune system, as well as specific functions in the urogenital system, lipid synthesis in the testes, erythropoiesis in the kidneys and the micturition reflex in the bladder. There is also evidence that telocytes are involved in pathologies in the kidneys, urethra, bladder, prostate, and testes.
A Synergistic Strategy with 3D Highly Conductive Carbon Matrix‐Decorated with Low Loading of CdS Quantum Dots as a Sulfur Host for Advanced Li−S Batteries
Authors: Li Yangping , Xu Jie , Xu Da , He Yun , Sun Xinyi , Niu Dongfang , Zhang Xinsheng
Published: April 2021

Lithium‐sulfur batteries (LSBs) have become one of the most competitive candidates for next generation energy storage systems due to the high theoretical energy density, nevertheless, the severe shuttle effect, volume expansion, and poor electrical conductivity restrict their practical application. Herein, we report a synergistic combination of 3D carbon matrix (CdS@NG‐CNT) composed of low‐defect carbon nanotubes (CNTs) and nitrogen‐doped graphene (NG) decorated with low loading of cadmium sulfide quantum dots as sulfur host and carbon black (CB) as separator layer to collectively solve these issues. Specifically, the developed host material possesses abundant macropores and mesopores and high electrical conductivity, which endow the carbon matrix multifaceted structural properties for polysulfides immobilization, electrons/Li+ transfer, and Li2S formation, as well as buffering the volume expansion during cycling. The CB‐modified separator can help to enhance the interconversion of intercepted polysulfides. Benefiting from these aspects, the cell equipped with CdS@NG‐CNT/S//CB‐PP exhibits a superior rate capacity of 1493.6 mA h/g at 0.2 C (1st), and maintains a capacity of 479.7 mA h/g after 1050 cycles with an ultralow capacity decay rate of 0.051 % at 1.0 C. This work provides a useful strategy to solve issues of the current LSBs, which may practically be used in the high‐energy density.
On the Differential Capacitance and Potential of Zero Charge of Au(111) in Some Aprotic Solvents
Authors: Shatla Ahmed S. , Landstorfer Manuel , Baltruschat Helmut
Published: April 2021

Voltammetric and Gouy‐Chapman capacitance minimum measurements were conducted on Au(111) and roughened Au(111) electrodes in aprotic electrolytes in the absence and presence of specifically adsorbed ions for concentrations ranging from 0.001 to 0.5 M. Negative of the point of zero charge (pzc), the capacitance maximum increases in the order Ca2+<Li+<K+, but the pzc value is independent of cation nature. The capacitance values have a slight dependence on cation type at a more negative potential. The pzc depends on the solvent and is influenced by the dielectric constant, metal‐solvent interactions and donor number; it is shifted to more positive values with increasing water content. Specific anion adsorption shifts the pzc to more negative values. The pzc value is more negative for the roughened electrode compared to the single crystal electrode. Propylene carbonate (PC) adsorption in the presence of perchlorate and iodide was examined on gold film by surface‐enhanced infrared absorption spectroscopy (SEIRAS). The potential dependent intensity is explained by a stronger electric field and thus a better alignment of the PC molecules when the absolute potential difference to the pzc is large.

The capacitance curves were theoretically modelled. From the capacitance maxima on both sides of the pzc the ionic volume and thus the solvation numbers were estimated. The width of the capacitance minimum is believed to be related to the layer of adsorbed solvent molecules.
An Ultrastable Crystalline Acylhydrazone‐Linked Covalent Organic Framework for Efficient Removal of Organic Micropollutants from Water
Authors: Zhao Yuling , Zhao Yue , Wu Cailing , Qiu Jikuan , Wang Huiyong , Li Zhiyong , Zhao Yang , Wang Jianji
Published: April 2021

As an important member of crystalline porous polymers, acylhydrazone‐linked covalent organic frameworks (COFs) have gained much attention in recent years. However, the low structural stability imparts a limit on their practical applications. To tackle this problem, we report a simple strategy to increase the chemical stability of acylhydrazone‐linked COFs by incorporating azobenzene groups in the conjugated framework. Through reinforcing the π‐π stacking interactions between the adjacent layers with increased π‐surface, it is surprising to find that the resulting materials exhibit extreme stability in harsh environments, such as in strong acid, strong base, aqueous educing agent and boiling water, even exposed to air for one year. As a proof‐of‐concept, such frameworks have been used to remove various organic micropollutants such as antibiotics, plastic components, endocrine disruptors, and carcinogens from water with high capacity, fast speed and excellent reusability over a wide pH range at environmentally relevant concentrations. The results provide a new avenue to significantly enhance the stability of COFs for practical applications.
1,2‐Carbopentafluorophenylation of Alkynes: The Metallomimetic Pull‐Push Reactivity of Tris(pentafluorophenyl)borane
Authors: Shibuya Masatoshi , Matsuda Miki , Yamamoto Yoshihiko
Published: April 2021

We report the novel single‐step 1,2‐dicarbofunctionalization of an arylacetylene with an allylsilane and tris(pentafluorophenyl)borane [B(C6F5)3] involving C−C bond formation with C−H bond scission at the β‐position to the silicon atom of an allylsilane and B→C migration of a C6F5 group. The 1,2‐carbopentafluorophenylation occurs smoothly without the requirement for a catalyst or heating. Mechanistic studies suggest that the metallomimetic “pull‐push” reactivity of B(C6F5)3 imparts consecutive electrophilic and nucleophilic characteristics to the benzylic carbon of the arylacetylene. Subsequent photochemical 6π‐electrocyclization affords tetrafluoronaphthalenes, which are important in the pharmaceutical and materials sciences. Owing to the unique reactivity of B(C6F5)3, the 1,2‐carbopentafluorophenylation using 2‐substituted furan proceeded with ring opening, and the reaction using silyl enolates formed a C−C bond with C−O bond scission at the silyloxy‐substituted carbon.
Highly Stereoselective Positional Isomerization of Styrenes viaAcid‐Catalyzed Carbocation Mechanism
Authors: Hu Xiao‐Si , He Jun‐Xiong , Zhang Ying , Zhou Jian , Yu Jin‐Sheng
Published: April 2021

Main observation and conclusion

The first transition metal‐free highly stereoselective positional isomerization of various α‐alkyl styrenes through a carbocation mechanism triggered strategy is developed by using Al(OTf)3 as a hidden Brønsted acid catalyst, which provides facile access to value‐added acyclic tri‐ and tetra‐substituted alkenes in good yields with high stereoselectivity under mild conditions. The practicality of this protocol is further highlighted by the gram‐scale synthesis, high stereoselectivity, good functional group tolerance, and simple operation. Mechanistic studies support that Al(OTf)3 acts as a hidden Brønsted acid catalyst and a carbocation intermediate is formed.
Interaction of a Triantennary Quinoline Glycoconjugate with the Asialoglycoprotein Receptor
Authors: Palit Subhadeep , Banerjee Sayanika , Mahata Tridib , Niyogi Sougata , Das Tanusree , Sova Mandi Chandra , Chakrabarti Partha , Dutta Sanjay
Published: April 2021

Targeted intracellular delivery is an efficient strategy for developing therapeutics against cancer and other intracellular infections. Nonspecific drug delivery shows limited clinical applications owing to high dosage, cytotoxicity, nonspecific action, high cost, etc. Therefore, targeted delivery of less cytotoxic drug candidates to hepatocytes through ASGPR‐mediated endocytosis could be an efficient strategy to surmount the prevailing shortcomings. In the present work, the gene encoding ASGPR‐H1‐CRD was amplified from Huh7 cells, cloned into pET 11a vector, and the ASGPR‐H1‐CRD protein was expressed and purified from E. coli. A novel triantennary galactose‐conjugated quinoline derivative 4 was synthesized that demonstrates 17‐fold higher binding affinity to isolated ASGPR‐H1‐CRD protein receptor (Kd∼54 μM) in comparison to D‐galactose (Kd∼900 μM). Moreover, micro‐calorimetric studies for the interaction of glycoconjugate 4 with ASGPR protein on live hepatocytes showed notable thermal response in case of ASGPR‐containing Huh7 cells, in comparison to non‐ASGPR Chang cells. These results might serve as an approach towards targeted delivery of small glycoconjugates to hepatocytes.
Germline mutations and age at onset of lung adenocarcinoma
Authors: Reckamp Karen L. , Behrendt Carolyn E. , Slavin Thomas P. , Gray Stacy W. , Castillo Danielle K. , Koczywas Marianna , Cristea Mihaela C. , Babski Kirsten M. , Stearns Donna , Marcum Catherine A. , Rodriguez Yenni P. , Hass Amie J. , Vecchio Mary M. , Mora Pamela , Cervantes Aleck E. , Sand Sharon R. , Mejia Rosa M. , Tsou Terrence C. , Salgia Ravi , Weitzel Jeffrey N.
Published: April 2021

Background

To identify additional at‐risk groups for lung cancer screening, which targets persons with a long history of smoking and thereby misses younger or nonsmoking cases, the authors evaluated germline pathogenic variants (PVs) in patients with lung adenocarcinoma for an association with an accelerated onset.

Methods

The authors assembled a retrospective cohort (1999‐2018) of oncogenetic clinic patients with lung adenocarcinoma. Eligibility required a family history of cancer, data on smoking, and a germline biospecimen to screen via a multigene panel. Germline PVs (TP53/EGFR, BRCA2, other Fanconi anemia [FA] pathway genes, and non‐FA DNA repair genes) were interrogated for associations with the age at diagnosis via an accelerated failure time model.

Results

Subjects (n = 187; age, 28‐89 years; female, 72.7%; Hispanic, 11.8%) included smokers (minimum of 5 pack‐years; n = 65) and nonsmokers (lighter ever smokers [n = 18] and never smokers [n = 104]). Overall, 26.7% of the subjects carried 1 to 2 germline PVs: TP53 (n = 5), EGFR (n = 2), BRCA2 (n = 6), another FA gene (n = 11), or another DNA repair gene (n = 28). After adjustment for smoking, sex, and ethnicity, the diagnosis of lung adenocarcinoma was accelerated 12.2 years (95% confidence interval [CI], 2.5‐20.6 years) by BRCA2 PVs, 9.0 years (95% CI, 0.5‐16.5 years) by TP53/EGFR PVs, and 6.1 years (95% CI, –1.0 to 12.6 years) by PVs in other FA genes. PVs in other DNA repair genes showed no association. Germline associations did not vary by smoking.

Conclusions

Among lung adenocarcinoma cases, germline PVs (TP53, EGFR, BRCA2, and possibly other FA genes) may be associated with an earlier onset. With further study, the criteria for lung cancer screening may need to include carriers of high‐risk PVs, and findings could influence precision therapy and reduce lung cancer mortality by earlier stage diagnosis.
Toward text psychology analysis using social spider optimization algorithm
Authors: Hosseinalipour Ali , Gharehchopogh Farhad Soleimanian , Masdari Mohammad , Khademi Ali
Published: April 2021

Abstract

Different nature‐inspired meta‐heuristic algorithms have been proposed to solve optimization problems. One of these algorithms is called social spider optimization (SSO) algorithm. Spiders' natural behaviors have inspired them to find the bait position by detecting vibrations in their web. Although the SSO algorithm has good accuracy in achieving optimal solutions, it suffers from a low convergence rate. In this paper, we attempted to improve SSO by changing its motion and mating parameters. To provide a practical example of using the new proposed algorithm, we based it on multi‐objective opposition‐based SSO, named MOPSSO. We used this algorithm in a feature selection process for analyzing text psychology, which is a multi‐objective problem. Textual psychology analysis is used in various fields, including collecting and analyzing people's views on various products, topics, social and political events. After selecting features, in order to classify the text, we used a new hybrid method that hybrids fuzzy C‐MEANS data clustering technique, a decision tree (DT), and Naïve Bayes (NB). Experimental results show that the improved SSO algorithm performs better than SSO, social spider algorithm, and CMA‐ES algorithms. Additionally, the performance of the proposed hybrid classification method is better than those of NB and DT.
Retracted: Weather forecasting and prediction using hybrid C5.0 machine learning algorithm
Authors: Murugan Bhagavathi Sudhan , Thavasimuthu Anitha , Murugesan Aruna , George Rajendran Charlyn Pushpa Latha , A Vijay , Raja Laxmi , Thavasimuthu Rajendran
Published: April 2021

In this research, a weather forecasting model based on machine learning is proposed for improving the accuracy and efficiency of forecasting. The aim of this research is to propose a weather prediction model for short‐range prediction based on numerical data. Daily weather prediction includes the work of thousands of worldwide meteorologists and observers. Modernized computers make predictions more precise than ever, and earth‐orbiting weather satellites capture pictures of clouds from space. However, in many cases, the forecast under many conditions is not accurate. Numerical weather prediction (NWP) is one of the popular methods for forecasting weather conditions. NWP is a major weather modeling tool for meteorologists which contributes to more accurate accuracy. In this research, the weather forecasting model uses the C5.0 algorithm with K‐means clustering. The C5.0 is one of the better decision tree classifiers, and the decision tree is a great alternative for forecasting and prediction. The algorithm for clustering the K‐means is used to combine identical data together. For this process, the clustering of K‐means is initially applied to divide the dataset into the closest cluster of K. For training and testing, the meteorological data collection obtained from the database Modern‐Era Historical Analysis for Research and Applications (MERRA) is used. The model's performance is assessed through MAE mean absolute error (MAE) and root mean square error (RMSE). And the proposed model is assessed with accuracy, sensitivity, and specificity for validation. The results obtained are compared with other current machine learning approaches, and the proposed model achieved predictive accuracy of 90.18%.
Fullerene‐Intercalated Graphitic Carbon Nitride as a High‐Performance Anode Material for Sodium‐Ion Batteries
Authors: Li Pengju , Shen Yanglin , Li Ximing , Huang Wenhuan , Lu Xing
Published: April 2021

Two‐dimensional (2D) graphitic carbon nitride (g‐CN) is a promising anode material for sodium‐ion batteries (SIBs), but its insufficient interlayer spacing and poor electronic conductivity impede its sodium storage capacity and cycling stability. Herein, we report the fabrication of a fullerene (C60)‐modified graphitic carbon nitride (C60@CN) material which as an anode material for SIBs shows a high‐reversible capacity (430.5 mA h g−1 at 0.05 A g−1, about 3 times higher than that of pristine g‐CN), excellent rate capability (226.6 mA h g−1 at 1 A g−1) and ultra‐long cycle life (101.2 mA h g−1 after 5000 cycles at 5 A g−1). Even at a high‐active mass loading of 3.7 mg cm−2, a reversible capacity of 316.3 mA h g−1 can be obtained after 100 cycles. Such outstanding performance of C60@CN is attributed to the C60 molecules distributed in the g‐CN nanosheets, which enhance the electronic conductivity and prevent g‐CN sheets from restacking, thus resulting in enlarged interlayer spacing and exposed edge N defects (pyridinic N and pyrrolic N) for sodium‐ion storage. Furthermore, a sodium‐ion full cell combining C60@CN anode and NVPF@rGO cathode provides high‐coulombic efficiency (>96.5%), exceptionally high‐energy density (359.8 W h kganode−1 at power density of 105.1 W kganode−1) and excellent cycling stability (89.2% capacity retention over 500 cycles at 1 A ganode−1). This work brings new insights into the field of carbon‐based anode materials for SIBs.
Surgical, clinical, and functional outcomes of transoral robotic surgery used in sleep surgery for obstructive sleep apnea syndrome: A systematic review and meta‐analysis
Authors: Lechien Jerome R. , Chiesa‐Estomba Carlos‐Miguel , Fakhry Nicolas , Saussez Sven , Badr Ibrahim , Ayad Tareck , Chekkoury‐Idrissi Younes , Melkane Antoine E. , Bahgat Ahmed , Crevier‐Buchman Lise , Blumen Marc , Cammaroto Giovanni , Vicini Claudio , Hans Stéphane
Published: April 2021

We investigated safety and efficacy of transoral robotic surgery (TORS) for base of tongue (BOT) reduction in obstructive sleep apnea syndrome (OSAS) patients. PubMed, Cochrane Library, and Scopus were searched. A meta‐analysis was performed. Random effects models were used. Thirty‐one cohorts met our criteria (1693 patients). The analysis was based mostly on retrospective studies. The summary estimate of the reduction of Apnea–Hypoxia Index (AHI) was 24.25 abnormal events per hour (95% CI: 21.69–26.81) and reduction of Epworth Sleepiness Scale (ESS) was 7.92 (95% CI: 6.50–9.34). The summary estimate of increase in lowest O2 saturation was 6.04% (95% CI: 3.05–9.03). The success rate of TORS BOT reduction, either alone or combined with other procedures, was 69% (95% CI: 64–79). The majority of studies reported low level of evidence but suggested that TORS BOT reduction may be a safe procedure associated with improvement of AHI, ESS, and lowest O2 saturation.
The type 2 diabetes mellitus susceptibility gene CDKAL1 polymorphism is associated with depressive symptom in first‐episode drug‐naive schizophrenic patients
Authors: Yin Xu Yuan , Chen Peng , Zhu Hai Wen , Yin Xiao Li , Ye Gang , Chi Yu Yan , Kang Zhao Peng , Sun Hong Yan , Hou Wen Long , Guan Lu Yang , Zhu Zhen Hua , Tang Zhen , Wang Jing , Zhang Guang Ya , Jia Qiu Fang , Hui Li
Published: April 2021

Background

Patients with schizophrenia have an increased prevalence of type 2 diabetes mellitus that has shown a significant association with the rs7754840 polymorphism in the gene encoding the cyclin‐dependent kinase 5 (CDK5) regulatory subunit‐associated protein 1‐like 1 (CDKAL1).

Objective

To examine whether this polymorphism was involved in the susceptibility in first‐episode drug‐naive schizophrenic patients (FDSP), and further influenced their clinical symptoms.

Methods

This polymorphism was genotyped in 239 FDSP and 368 healthy controls. The clinical symptoms in FDSP were assessed using the Positive and Negative Syndrome Scale (PANSS) five‐factor models.

Results

There was no significant difference in the allelic and genotypic frequencies of this polymorphism between two groups (both p > 0.05) after adjusting for covariates. However, the PANSS depressive score significantly differed by genotype in FDSP after adjusting for covariates (F = 5.25, p = 0.006). This significant difference also persisted after Bonferroni correction (p < 0.05). FDSP with C/C genotype had significantly higher PANSS depressive score than those with C/G genotype (p = 0.007) and those with G/G genotype (p = 0.005). Moreover, further stepwise multivariate regression analysis showed the significant association between the rs7754840 polymorphism and PANSS depressive score in FDSP (β = −1.07, t = −2.75, p = 0.007).

Conclusions

Our findings demonstrated that although the CDKAL1 rs7754840 polymorphism did not contribute to the susceptibility to FDSP, it might be implicated in depressive symptoms in this patient group.
Fifty years of runoff response to conversion of old‐growth forest to planted forest in the H. J. Andrews Forest, Oregon, USA
Authors: Crampe Emily A. , Segura Catalina , Jones Julia A.
Published: April 2021

Long‐term watershed experiments provide the opportunity to understand forest hydrology responses to past logging, road construction, forest regrowth, and their interactions with climate and geomorphic processes such as road‐related landslides. We examined a 50‐year record from paired‐watershed experiments in the H. J. Andrews Experimental Forest, Oregon, USA in which 125 to 450‐year‐old conifer forests were harvested in the 1960s and 1970s and converted to planted conifer forests. We evaluated how quickflow and delayed flow for 1222 events in treated and reference watersheds changed by season after clearcutting and road construction, including 50 years of growth of planted forest, major floods, and multi‐decade reductions in snowpack. Quickflow runoff early in the water year (fall) increased by up to +99% in the first decade, declining to below pre‐harvest levels (−1% to −15%) by the third to fifth decade after clearcutting. Fall delayed flow responded more dramatically than quickflow and fell below pre‐treatment levels in all watersheds by the fifth decade, consistent with increased transpiration in the planted forests. Quickflow increased less (+12% to 70%) during the winter and spring but remained higher than pre‐treatment levels throughout the fourth or fifth decade, potentially impacted by post‐harvest burning, roads, and landslides. Quickflow remained high throughout the 50‐year period of study, and much higher than delayed flow in the last two decades in a watershed in which road‐related changes in flow routing and debris flows after the flood of record increased network connectivity. A long‐term decline in regional snowpack was not clearly associated with responses of treated vs. reference watersheds. Hydrologic processes altered by harvest of old‐growth conifer forest more than 50 years ago (transpiration, interception, snowmelt, and flow routing) continued to modify streamflow, with no clear evidence of hydrologic recovery. These findings underscore the importance of continued long‐term watershed experiments.
Fault zone hydrogeology in arid environments: The origin of cold springs in the Wadi Araba Basin, Egypt
Authors: Khalil Mahmoud M. , Hamer Kay , Pichler Thomas , Abotalib Abotalib Z.
Published: April 2021

The role of faults in controlling groundwater flow in the Sahara and most of the hyper‐arid deserts is poorly understood due to scarcity of hydrological data. The Wadi Araba Basin (WAB), in the Eastern Sahara, is highly affected by folds and faults associated with Senonian tectonics and Paleogene rifting. Using the WAB as a test site, satellite imagery, aeromagnetic maps, field observations, isotopic and geochemical data were examined to unravel the structural control on groundwater flow dynamics in the Sahara. Analysis of satellite imagery indicated that springs occur along structurally controlled scarps. Isotopic data suggested that cold springs in the WAB showed a striking similarity with the Sinai Nubian aquifer system (NAS) water and the thermal springs along the Gulf of Suez (e.g., δ18O = −8.01‰ to −5.24‰ and δD = −53.09‰ to −31.12‰) demonstrating similar recharge sources. The findings advocated that cold springs in the WAB represent a natural discharge from a previously undefined aquifer in the Eastern Desert of Egypt rather than infiltrated precipitation over the plateaus surrounding the WAB or through hydrologic windows from deep crystalline basement flow. A complex role of the geological structures was inferred including: (1) channelling of the groundwater flow along low‐angle faults, (2) compartmentalization of the groundwater flow upslope from high‐angle faults, and (3) reduction of the depth to the main aquifer in a breached anticline setting, which resulted in cold spring discharge temperatures (13–22°C). Our findings emphasize on the complex role of faults and folds in controlling groundwater flow, which should be taken into consideration in future examination of aquifer response to climate variability in the Sahara and similar deserts worldwide.
The Buck Creek‐Boreas River Adirondack watershed monitoring program
Authors: Lawrence Gregory B. , Siemion Jay
Published: April 2021

The Buck Creek‐Boreas River Adirondack Watershed Monitoring Program, located in the Adirondack region of New York State, United States, combines the monitoring of headwater streams, soils, and vegetation based on a watershed design. Continuous monitoring of six watersheds is linked to the sampling of more than 400 additional Adirondack streams between 2003 and 2019 for chemical analysis of 14 constituents throughout the highly valued Adirondack ecoregion that covers an area of more than 24 000 km2. Much of this landscape has a low capacity for acid buffering, but due to spatial variation in geologic features, some areas are moderately to well acid buffered. This program includes data that extends back to the early 1980s and is ongoing. The focus of the program is on the watersheds of headwater Adirondack streams. Soil, vegetation and stream data are used to better understand environmental effects on the linkages of these ecosystem components. Documentation of the long‐term responses of Adirondack ecosystems to environmental disturbances such as acid rain, climate change and other unforeseen factors is the primary objective of the program.