Nitrite (NO2 –) is the primary reduction product of nitrate (NO3 –), which is the most predominant contaminant in global freshwater. Both species present major environmental challenges; NO2 – is also highly toxic to humans. Available technologies for the removal of NO3 – and NO2 – from potable water are hampered by a number of issues, which limit their widespread usage. Catalytic degradation of NO3 – and NO2 – is a potentially disruptive technology. However, the high cost of palladium metal required for this process is a significant economic barrier. Herein, we report the synthesis of scalable catalyst materials based on randomly alloyed palladium–silver nanoparticles. These catalysts significantly lower the overall catalyst cost and simultaneously achieve a 3.4-times increase in the catalytic activity for NO2 – hydrogenative reduction. Density functional theory (DFT) studies reveal that alloying Pd with Ag creates more favorable surface binding sites, which is the origin of the increased catalytic activity. The catalysts are also highly selective toward the production of nitrogen gas over ammonia.

Nitrate (NO3 –) has impacted more groundwater supplies than any other pollutant in the world. It is currently removed at water treatment plants by ion exchange, which is effective but comes at a steep financial and environmental cost. (Electro)­catalytic treatment of nitrate has emerged as a promising alternative technology, which relies on reducing nitrate to dinitrogen gas or ammonium via reduction on a bimetal catalyst with atomic hydrogen oxidation. The bimetal catalyst contains a platinum group metal, and atomic hydrogen is either generated from supplied hydrogen gas (catalytic) or an applied current (electrocatalytic). However, (electro)­catalytic treatment of nitrate is not being implemented at water treatment plants. This perspective addresses the most important technical challenges limiting widespread adoption of (electro)­catalytic nitrate removal in drinking water treatment. These challenges affect precious metal amounts and cost, the efficiency and safety of hydrogen use, and end-product selectivity. This perspective is concluded by a prioritization of technology challenges, and their implications for attracting industry investment and achieving regulatory acceptance.

Olefin CM followed by transfer hydrogenation is an efficient method for synthesizing amphiphilic hydroxypropyl cellulose derivatives.

Mutations in chromatin-modifying proteins and transcription factors are commonly associated with a wide variety of cancers. Through gain-or loss-of-function, these mutations may result in characteristic alterations of accessible chromatin, indicative of shifts in the landscape of regulatory elements genome-wide. The identification of compounds that reverse a specific chromatin signature could lead to chemical probes or potential therapies. To explore whether chromatin accessibility could serve as a platform for small molecule screening, we adapted formaldehyde-assisted isolation of regulatory elements (FAIRE), a chemical method to enrich for nucleosomedepleted genomic regions, as a high-throughput, automated assay. After demonstrating the validity and robustness of this approach, we applied this method to screen an epigenetically targeted small molecule library by evaluating regions of aberrant nucleosome depletion mediated by EWSR1-FLI1, the chimeric transcription factor critical for the bone and soft tissue tumor Ewing sarcoma. As a class, histone deacetylase inhibitors were greatly overrepresented among active compounds. These compounds resulted in diminished accessibility at targeted sites by disrupting transcription of EWSR1-FLI1. Capitalizing on precise differences in chromatin accessibility for drug discovery efforts offers significant advantages because it does not depend on the a priori selection of a single molecular target and may detect novel biologically relevant pathways.chromatin | Ewing sarcoma | high throughput screening | FAIRE | histone deacetylase inhibitor A growing range of human cancers have been associated with mutations in genes encoding proteins that regulate chromatin, the assembly of proteins and DNA that control DNAtemplated processes, including transcription and replication (1, 2). Small molecule drugs and chemical probes offer an approach to explore the biological consequences of these mutations and are emerging as a therapeutic strategy to target disease pathways. Drugs targeting histone deacetylase (HDAC) enzymes, the bromodomain reader BRD4, and DNA methylation have already received regulatory approval or have entered clinical testing, and chemical probes have been developed against a broad range of chromatin regulators, such as the methyltransferases (3) DOT1L (4), EZH2 (5-8), and G9a (9, 10), and the reader proteins L3MBTL3 (11) and BRD4 (12-14). However, transcription factors that lack enzymatic activity or binding pockets with targetable molecular features have been considered "undruggable," and a reductionist approach based on identification of their molecular targets has largely failed.The majority of Ewing sarcomas, highly malignant pediatric bone and soft tissue tumors, harbor a chromosomal translocation that joins the amino-terminal domain of EWSR1 with the DNA binding domain of the ETS transcription factor family member FLI1 to generate the chimeric transcription factor EWSR1-FLI1 (15). Translocations with other ETS genes are detected in most of the remaining tumors, y...