Volume 90, Issue 7

An amide-promoted protocol was developed for the reductive functionalization of CO 2 with amines/imine and phenylsilane to produce methylamine. Secondary amines and an imine were methylated successfully to methylamines with up to 98% yield under atmospheric pressure of CO 2 and 80°C. Furthermore, a tentative mechanism involving amide-promoted CO 2 reduction to the silyl acetal species was proposed. Striking features of this metal-free protocol are selective six-electron reduction of CO 2 with hydrosilane as a reductant in the presence of amine.

The leaching of valuable metals from mineral ores is the basis of several extractive economies around the world, but the strategies employed often need to rely on dangerous compounds such as cyanides. Due to the complex nature of most ores, leaching processes are slow and have a low efficiency in noble metal extraction, which is usually improved by fine-milling the mineral. In this manuscript, we consider this strategy, demonstrating that it may increase the amount of silver leaching, but at the expense of a higher consumption of cyanide, which renders the process inefficient (only 2% of consumed cyanide is employed to complex silver). The increase in the yield of the desired product without the smarter use of dangerous compounds is shown as a paradigm of the need to insert green chemistry principles in industrial processes. We further present the result of two potential strategies for greener mineral processing: the use of ultrasound to eliminate passivating layers formed during the leaching process and the use of chemical pretreatments to eliminate possible sources of passivation. These strategies can increase the amount of silver extraction and simultaneously increase the efficiency in cyanide consumption. The convenience of these pretreatments in the framework of the green chemistry principles, as well as the challenges towards their implementation at industrial scale, is discussed.

Recommendations are given concerning the terminology of methods of bioanalytical chemistry. With respect to dynamic development particularly in the analysis and investigation of biomacromolecules, terms related to bioanalytical samples, enzymatic methods, immunoanalytical methods, methods used in genomics and nucleic acid analysis, proteomics, metabolomics, glycomics, lipidomics, and biomolecules interaction studies are introduced.

This document describes the application of the syntax, semantic rules, and format of the Nomenclature for Properties and Units (NPU) terminology for coded dedicated kinds-of-property in the subject field of clinical molecular genetics. A vocabulary for NPU definitions in this field, based on international terminology and nomenclature, is introduced and examples of actual NPU definitions for different types of investigations are given and explained.

The standard atomic weights of the elements apply to normal materials. Since 1984, the Commission on Isotopic Abundances and Atomic Weights (Commission) has defined a normal material as: “The material is a reasonably possible source for this element or its compounds in commerce, for industry or science; the material is not itself studied for some extraordinary anomaly and its isotopic composition has not been modified significantly in a geologically brief period.” The term “a geologically brief period” in this definition is confusing, and confusion can be reduced by revising this definition to the following, which was accepted by the Commission on Isotopic Abundances and Atomic Weights at its meeting in Groningen, Netherlands in September 2017: “ Normal materials include all substances, except (1) those subjected to substantial deliberate, undisclosed, or inadvertent artificial isotopic modification, (2) extraterrestrial materials, and (3) isotopically anomalous specimens, such as natural nuclear reactor products from Oklo (Gabon) or other unique occurrences.”