Relationship between radiofrequency-electromagnetic radiation from cellular phones and brain tumor: meta-analyses using various proxies for RF-EMR exposure-outcome assessment.

Introduction: The authors conducted meta-analyses regarding the association between cellular and mobile phone use and brain tumor development by applying various radiofrequency-electromagnetic radiation (RF-EMR) exposure subcategories. With changing patterns of mobile phone use and rapidly developing Wireless Personal Area Network (WPAN) technology (such as Bluetooth), this study will provide insight into the importance of more precise exposure subcategories for RF-EMR.

Methods: The medical librarian searched MEDLINE (PubMed), EMBASE, and the Cochrane Library until 16 December 2020.

Quantitative analysis of phthalates using a pyrolyzer gas chromatography/mass spectrometry method.

A pyrolyzer gas chromatography/mass spectrometry (GC/MS) method eliminates toxic solvents that burden our environment and can address the crucial problem of the solvent extraction GC/MS method. The purpose of this study is to establish an efficient quantitative analysis method for 10 phthalates that are regulated by the several governments. A change of concentrations over time for phthalates and internal standards was measured to verify the feasibility of using an auto sampler that facilitates analyzing multiple samples.

Synthesis of Arenesulfonyl Fluorides via Sulfuryl Fluoride Incorporation from Arynes.

Transition-metal-free multicomponent reactions involving aryne precursors, secondary amines, and sulfuryl fluoride are reported herein. Zwitterionic intermediates formed from the reaction of arynes with amine nucleophiles can capture SOF under mild conditions, offering a novel and practical protocol for the synthesis of 2-dialkyl-, 2-alkylaryl-, or 2-diarylamino-substituted arenesulfonyl fluoride derivatives in good to excellent yields.

Mechanistic studies of magnetically recyclable Pd - Fe3O4 heterodimeric nanocrystal-catalyzed organic reactions.

Recently, we have reported several catalytic applications of new Pd - Fe3 O4 heterodimeric nanocrystals as magnetically separable catalysts. Successful applications of the nanocrystals towards various useful organic reactions such as Suzuki, Heck, and Sonogashira coupling reactions, direct C - H arylation, and Wacker oxidation have been recorded. However, detailed mechanistic courses of the reactions have not been delineated, and it was not clear whether these processes proceeded through a homogeneous or heterogeneous mechanism.