Systematic review of the association between talc and female reproductive tract cancers.

Talc is a hydrous magnesium sheet silicate used in cosmetic powders, ceramics, paints, rubber, and many other products. We conducted a systematic review of the potential carcinogenicity of genitally applied talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM, now the National Academy of Medicine) and several US EPA frameworks for systematic reviews, evaluating and integrating the epidemiological, animal, and mechanistic literature on talc and cancer.

Systematic review of the scientific evidence of the pulmonary carcinogenicity of talc.

We conducted a systematic review to assess the potential pulmonary carcinogenicity of inhaled talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM) and several United States (US) Environmental Protection Agency (EPA) frameworks for systematic reviews. A comprehensive literature search was conducted.

Potential airborne asbestos exposures in dentistry: a comprehensive review and risk assessment.

Chrysotile was formerly used in the manufacture of casting ring liner (CRL) and periodontal dressing powder (PDP). The purpose of this study was to describe the potential for airborne asbestos exposure among dental professionals who may have used these products and to assess their risk of asbestos-related disease (ARD). Task-specific exposure data associated with CRL and PDP were identified and compared to regulatory standards for asbestos and health-based benchmarks.

Active pharmaceutical contaminants in dietary supplements: A tier-based risk assessment approach.

The presence of active pharmaceutical ingredients (APIs) in adulterated or contaminated dietary supplements is a current product safety concern. Since there are limited guidelines, and no published consensus methods, we developed a tier-based framework incorporating typical lines of evidence for determining the human health risk associated with APIs in dietary supplements. Specifically, the tiered approach outlines hazard identification and decision to test for APIs in products based on criteria for likelihood of contamination or adulteration, and evaluation of manufacturer production standards.

A quantitative weight of evidence assessment of Hill's guidelines for causal inference for cosmetic talc as a cause of mesothelioma.

Cosmetic talc has been suggested to cause mesothelioma. To assess a potential causal relationship between cosmetic talc and mesothelioma, a quantitative weight of evidence analysis was performed in accordance with Hill's nine original guidelines for causal inference using a published empirical model to weight each respective guideline. Various epidemiological, toxicological, and exposure studies related to cosmetic talc and risk of mesothelioma were included in an evaluation of each of Hill's guidelines.

Phenanthroline-based metal-organic frameworks for Fe-catalyzed C-H amination.

We report here the synthesis of a robust and highly porous Fe-phenanthroline-based metal-organic framework (MOF) and its application in catalyzing challenging inter- and intramolecular C-H amination reactions. For the intermolecular amination reactions, a FeBr-metalated MOF selectively functionalized secondary benzylic and allylic C-H bonds. The intramolecular amination reactions utilizing organic azides as the nitrene source required the reduction of the FeBr-metalated MOF with NaBHEt to generate the active catalyst.

Single-Site Cobalt Catalysts at New Zr(μ-O)(μ-OH)(μ-OH) Metal-Organic Framework Nodes for Highly Active Hydrogenation of Nitroarenes, Nitriles, and Isocyanides.

We report here the synthesis of a robust and porous metal-organic framework (MOF), Zr-TPDC, constructed from triphenyldicarboxylic acid (HTPDC) and an unprecedented Zr secondary building unit (SBU): Zr(μ-O)(μ-OH)(μ-OH). The Zr-SBU can be viewed as an inorganic node dimerized from two commonly observed Zr clusters via six μ-OH groups. The metalation of Zr-TPDC SBUs with CoCl followed by treatment with NaBEtH afforded a highly active and reusable solid Zr-TPDC-Co catalyst for the hydrogenation of nitroarenes, nitriles, and isocyanides to corresponding amines with excellent activity and selectivity.

Cerium-Hydride Secondary Building Units in a Porous Metal-Organic Framework for Catalytic Hydroboration and Hydrophosphination.

We report the stepwise, quantitative transformation of Ce(μ-O)(μ-OH)(OH)(OH) nodes in a new Ce-BTC (BTC = trimesic acid) metal-organic framework (MOF) into the first Ce(μ-O)(μ-OLi)(H)(THF)Li metal-hydride nodes that effectively catalyze hydroboration and hydrophosphination reactions. CeH-BTC displays low steric hindrance and electron density compared to homogeneous organolanthanide catalysts, which likely accounts for the unique 1,4-regioselectivity for the hydroboration of pyridine derivatives. MOF nodes can thus be directly transformed into novel single-site solid catalysts without homogeneous counterparts for sustainable chemical synthesis.

Single-Site Cobalt Catalysts at New Zr8(μ2-O)8(μ2-OH)4 Metal-Organic Framework Nodes for Highly Active Hydrogenation of Alkenes, Imines, Carbonyls, and Heterocycles.

We report here the synthesis of robust and porous metal-organic frameworks (MOFs), M-MTBC (M = Zr or Hf), constructed from the tetrahedral linker methane-tetrakis(p-biphenylcarboxylate) (MTBC) and two types of secondary building units (SBUs): cubic M8(μ2-O)8(μ2-OH)4 and octahedral M6(μ3-O)4(μ3-OH)4. While the M6-SBU is isostructural with the 12-connected octahedral SBUs of UiO-type MOFs, the M8-SBU is composed of eight M(IV) ions in a cubic fashion linked by eight μ2-oxo and four μ2-OH groups. The metalation of Zr-MTBC SBUs with CoCl2, followed by treatment with NaBEt3H, afforded highly active and reusable solid Zr-MTBC-CoH catalysts for the hydrogenation of alkenes, imines, carbonyls, and heterocycles.

Chemoselective single-site Earth-abundant metal catalysts at metal-organic framework nodes.

Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones.