scholarly journals Regiocontrolled Allylic Functionalization of Internal Alkene via Selenium-pi-Acid Catalysis Guided by Boron Substitution

2021 ◽  
Author(s):  
Wang Honggen ◽  
Ling Yang ◽  
Yuan Liu ◽  
Wen-Xin Fan ◽  
Dong-Hang Tan ◽  
...  
Keyword(s):  
Acid Catalysis ◽  
Functional Group ◽  
Key Factor ◽  
Boron Substitution

The selenium-pi-acid-catalysis has received increasing attention as powerful tools for olefin functionalization, but the regioselectivity is often problematic. Reported herein is a selenium-catalyzed regiocontrolled olefin transpositional chlorination and imidation reaction. The reaction outcome benefits from an allylic B(MIDA) substitution. And the stabilization of α-anion from a hemilabile B(MIDA) moiety was believed to be the key factor for selectivity. Broad substrate scope, good functional group tolerance and generally good yields were observed. The formed products were demonstrated to be valuable precursors for the synthesis a wide variety of structurally complex organoborons.

scholarly journals Woody flora of natural forest gaps in a bamboo-dominated forest remnant in southwestern Amazonia

Check List ◽  
2016 ◽  
Vol 12 (3) ◽  
pp. 1891
Author(s):  
Álisson Sobrinho Maranho ◽  
Cleber Ibraim Salimon ◽  
Daniel Da Silva Costa
Keyword(s):  
Woody Plants ◽  
Functional Group ◽  
Floristic Composition ◽  
Forest Gaps ◽  
Threat Status ◽  
Forest Remnant ◽  
Key Factor ◽  
Local Plant ◽  
Brazilian Flora ◽  
Southwestern Amazonia

Abstract: Forest gaps, created by the falling of one or more trees, have been seen as a key factor for the maintenance of local plant diversity in tropical forests. In this study, our goal was to determine the floristic composition of woody plants colonizing natural gaps and in the understory of an open, bamboo-dominated (Guadua weberbaueri Pilg.) forest in southwestern Amazonia, Acre, Brazil. We sampled and identified woody plants (≥1 m tall and DBH≤10 cm) in 20 forest gaps and nine adjacent understories. In total, 1656 plants were identified in 159 species, 116 genera and 45 families. A list of species was created, containing habitat, habit, functional group, threat status (Brazilian Flora Red List) and abundance data for each species.

scholarly journals Cationic Single-Chained Surfactants with a Functional Group at the End of the Hydrophobic Tail DNA Compacting Efficiency

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 589
Author(s):  
José Antonio Lebrón ◽  
Pilar López-Cornejo ◽  
Elena García-Dionisio ◽  
Pablo Huertas ◽  
Margarita García-Calderón ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Functional Group ◽  
Transfection Efficiency ◽  
Constitutive Expression ◽  
Regulatory Elements ◽  
Ammonium Bromide ◽  
Calf Thymus ◽  
Key Factor ◽  
Hydrophobic Tail ◽  
Self Aggregation

The interaction between calf-thymus DNA, ctDNA, and various single-chained surfactants with different functional groups at the end of hydrophobic tail was studied with the goal of investigating the influence of the functional group nature on surfactant DNA compacting efficiency. The surfactants investigated were dodecyltriethylammonium bromide (DTEABr), triethyl(1-phenoxydodecyl)ammonium bromide (12PhBr), triethyl(2-naphthoxydodecyl)ammonium bromide (12NBr) and 11-(isonicotinoyloxy)-N,N,N-triethyl-1-undecanaminium bromide (11PyBr). Results made evident that the surfactants’ tendencies to self-aggregation is the key factor determining their efficiency to compact the nucleic acid. Subsequently, DOPE/12NBr/pEGFP-C1 lipoplexes, with different cationic surfactant molar fractions (α) and mass ratios (L/D), were prepared and characterized. DOPE is a zwitterionic phospholipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, and the plasmid pEGFP-C1 carries a GFP coding sequence with the necessary regulatory elements for constitutive expression of the gene in human cells. 12NBr was chosen because it was the most efficient DNA compacting agent among the surfactants investigated. Finally, the cytotoxicity and transfection efficiency (TE) of DOPE/12NBr/pDNA lipoplexes, with different compositions, were investigated.

Aerobic Allylation of Alcohols with Non-Activated Alkenes Enabled by Light-Driven Selenium-π-Acid Catalysis

Synthesis ◽  
2018 ◽  
Vol 50 (19) ◽  
pp. 3875-3885 ◽  
Author(s):  
Alexander Breder ◽  
Katharina Rode ◽  
Martina Palomba ◽  
Stefan Ortgies ◽  
Rene Rieger
Keyword(s):  
Electron Transfer ◽  
Transfer Process ◽  
Acid Catalysis ◽  
Functional Group ◽  
Ambient Air ◽  
Electron Transfer Process ◽  
Optimized Conditions ◽  
Very High

A new organocatalytic protocol for the aerobic dehydrogenative allylation of alcohols using non-activated alkenes as the allylating reagent and ambient air as the terminal oxidant is established. Mechanistically, the procedure relies on the interplay of a diselane and a photo­redox catalyst by means of a light-induced electron transfer process. Under optimized conditions, a broad range of both cyclic and acyclic ethers is accessed with very high functional group tolerance and excellent regioselectivity.

Attachment of oral bacteria to titanium surfaces: An SEM study

1994 ◽  
Vol 52 ◽  
pp. 468-469
Author(s):  
J. E. Laffoon ◽  
R. L. Anderson ◽  
J. C. Keller ◽  
C. D. Wu-Yuan
Keyword(s):  
Technical Problem ◽  
Titanium Implant ◽  
Oral Bacteria ◽  
Bacterial Cells ◽  
Thin Sections ◽  
Surface Ultrastructure ◽  
Sem Study ◽  
Key Factor ◽  
Titanium Surfaces

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).

Forum: Morphological Awareness as a Key Factor in Language-Literacy Success for Academic Achievement

2020 ◽  
Vol 51 (3) ◽  
pp. 509-513
Author(s):  
Ashley Bourque Meaux ◽  
Julie A. Wolter ◽  
Ginger G. Collins
Keyword(s):  
Academic Achievement ◽  
Academic Success ◽  
Literacy Development ◽  
Morphological Awareness ◽  
Language And Literacy ◽  
Speech Language Pathologists ◽  
School Based ◽  
Literacy Success ◽  
Key Factor ◽  
Language And Literacy Development

Purpose This article introduces the Language, Speech, and Hearing Services in Schools Forum: Morphological Awareness as a Key Factor in Language-Literacy Success for Academic Achievement. The goal of this forum is to relate the influence morphological awareness (MA) has on overall language and literacy development with morphology acting as the “binding agent” between orthography, phonology, and semantics ( Perfetti, 2007 ) in assessment and intervention for school-aged children. Method This introduction provides a foundation for MA development and explores the influence MA has over the course of school-aged language and literacy development. Through summaries of the 11 articles in this forum, school-based speech-language pathologists will be able to convey the importance of MA to promote successful educational outcomes for kindergarten to adolescent students. The forum explores researcher-developed assessments used to help identify MA skill level in first- through eighth-grade students at risk for literacy failure to support instructional needs. The forum also provides school-based speech-language pathologists with details to design and implement MA interventions to support academic success for school-aged students with varying speech-language needs (e.g., dual language emersion, vocabulary development, reading comprehension) using various service delivery models (e.g., small group, classroom-based, intensive summer camps). Conclusion MA is effective in facilitating language and literacy development and as such can be an ideally focused on using multilinguistic approaches for assessment and intervention. The articles in this issue highlight the importance in assessment measures and intervention approaches that focus on students' MA to improve overall academic success in children of all ages and abilities.

1451: Positive Efect of Prostaglandin on Regulation of Prostate Blood Flow-Investigation of the Key Factor in the Signaling Pathway of The Prostate Blood Flow-

2005 ◽  
Vol 173 (4S) ◽  
pp. 393-393
Author(s):  
Bunzo Kashiwagi ◽  
Yasuhiro Shibata ◽  
Kazunari Ohki ◽  
Seiji Arai ◽  
Seijiro Honma ◽  
...  
Keyword(s):  
Blood Flow ◽  
Signaling Pathway ◽  
Flow Investigation ◽  
Key Factor
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