Mineral Resources: Stocks, Flows, and Prospects

This chapter focuses on metals as they provide the clearest example of the challenges and opportunities that mineral resources present to society, in terms of both primary production and recycling. Basic concepts, information requirements and sources of consumer and industrial resource demand are described as well as the destabilizing effects of volatile resource prices and supply chain disruptions. Challenges facing extraction of in-ground resources and production of secondary resources are discussed and scenarios for the future considered. The results of the scenarios indicate that particularly energy and, as well, water and land requirements could become increasingly constraining factors for metal production. Key research questions are posed and modeling and data priorities discussed, with an emphasis on areas that require novel concepts and analytic tools to help lessen negative environmental impacts associated with minerals. The challenge of sustainability requires collaboration of practitioners and analysts with a multidisciplinary understanding of a broad set of issues, including economics, engineering, geology, ecology, and mathematical modeling, to name a few, as well as policy formulation and implementation.

Effect of tibolone on breast cancer cell proliferation in postmenopausal ER+ patients: Results from STEM trial

Purpose: Tibolone is a selective tissue estrogenic activity regulator, approved for the treatment of vasomotor symptoms in postmenopausal women. We have done an exploratory, double-blind, randomized, placebo-controlled pilot trial to investigate the tissue-specific effects of 2.5 mg tibolone on breast cancer in postmenopausal women, in particular on tissue proliferation (STEM, Study of Tibolone Effects on Mamma carcinoma tissue). Experimental Design: Postmenopausal women with initially stage I/II, estrogen receptor-positive (ER+) primary breast cancer, were randomly assigned to 14 days of placebo or 2.5 mg/d tibolone. Core biopsies of the primary tumor were obtained before and after treatment. Ki-67 and apoptosis index were analyzed in baseline and corresponding posttreatment specimen. Results: Of 102 enrolled patients, 95 had evaluable data. Baseline characteristics were comparable between both treatment groups. Breast cancer cases are mainly invasive (99%), stage I or II (42% and 50% respectively), and ER+ (99%). Median intratumoral Ki-67 expression at baseline was 13.0%, in the tibolone group and 17.8% in the placebo group, and decreased to 12.0% after 14 days of tibolone while increasing to 19.0% in the placebo group. This change from baseline was not significantly different between tibolone and placebo (Wilcoxon test; P = 0.17). A significant difference was observed between the treatment groups when the median change from baseline apoptosis index was compared between the treatment groups (tibolone, 0.0%; placebo, +0.3%; Wilcoxon test; P = 0.031). The incidence of adverse effects was comparable. Conclusions: In ER+ breast tumors, 2.5 mg/d tibolone given for 14 days has no significant effect on tumor cell proliferation

Critical raw materials: A perspective from the materials science community

Functional materials are crucial to meet today's societal challenges and needs, such as the transition towards low carbon energy production to reduce climate change, renewable energies and green economy, clean mobility and improved communication. In order to fulfill specific functions, many of these materials require a variety of specific metallic elements whose total reserves in primary deposits on the planet are limited in quantity and unevenly distributed, respectively require significant efforts for exploration and investments in their exploitation. Furthermore, the extraction and processing of the corresponding metallic minerals can be sometimes related to a high environmental burden as well as frequently negative social impacts. While in contrast to fossil fuels mineral materials can be principally recycled and hence kept as resources, closing the materials loop especially for many specialty metals today is often hampered by dissipation as well as by physical and economic challenges. These metallic elements are also listed under "critical raw materials" which have been receiving increased attention in scientific and policy-related debates over the last decade and years. In this paper, we introduce the topic of materials criticality for the special issue of Sustainable Materials and Technologies and observe how the criticality of raw materials is perceived and handled within Materials Science. For this, we (i) present examples of critical raw materials in advanced technologies, (ii) summarize some definitions of criticality, (iii) outline the topic of critical raw materials in the Material Scientist community by highlighting relevant outcomes of a survey on critical raw materials for materials scientists, and (iv) conduct a literature research on "Critical Raw Materials" and "Criticality" in search engines commonly used by materials scientists. The results show that material scientists seem frequently not concerned with the criticality of raw materials in their work, and that the relevant terms appear for a broader scientific community mainly in the fields of environmental science, chemistry-related processing and environmental and resource management. The paper presents and discusses these results and suggests to advance the implementation of the concept of materials criticality in materials research and development. (C) 2018 Elsevier B.V. All rights reserved