Highly efficient and stable electrocatalysts, particularly those that are capable of multifunctionality in the same electrolyte, are in high demand for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). In this work, highly monodisperse CoP and Co P nanocrystals (NCs) are synthesized using a robust solution-phase method. The highly exposed (211) crystal plane and abundant surface phosphide atoms make the CoP NCs efficient catalysts toward ORR and HER, while metal-rich Co P NCs show higher OER performance owing to easier formation of plentiful Co P@COOH heterojunctions. Density functional theory calculation results indicate that the desorption of OH* from cobalt sites is the rate-limiting step for both CoP and Co P in ORR and that the high content of phosphide can lower the reaction barrier. A water electrolyzer constructed with a CoP NC cathode and a Co P NC anode can achieve a current density of 10 mA cm at 1.56 V, comparable even to the noble metal-based Pt/C and RuO /C pair. Furthermore, the CoP NCs are employed as an air cathode in a primary zinc-air battery, exhibiting a high power density of 62 mW cm and good stability.

In the colloidal synthesis of inorganic perovskite materials, cesium oleate (CsOL) is the most commonly used Cs precursor. Yet, despite its ubiquitous use in literature, CsOL has been observed to be insoluble at room temperature and leads to surprisingly inconsistent results in CsPbX3 nanocrystal synthesis, depending on the Cs salt from which the precursor is derived. We show that under the conditions used in most reports, the amount of oleic acid (OA) added, while stoichiometrically sufficient, still leads to incomplete conversion of the Cs salts to CsOL. This results in a mixture of Cs sources being present during the reaction, causing decreased homogeneity and reproducibility. When a 1:5 Cs:OA ratio is used, complete conversion is readily obtained, even under mild conditions, resulting in a precursor solution that is soluble at room temperature and yields identical synthetic results, regardless of the initial Cs source. Furthermore, 1H nuclear magnetic resonance (NMR) of solutions prepared using varying Cs:OA ratios shows that the maximum ratio of Cs:OA obtainable in solution is 1:5, with any excess Cs present in the precipitate. We believe the use of a soluble, fully converted CsOL reagent will improve reproducibility for Cs-based perovskite synthesis and directly benefit synthetic methods based on microfluidics.

Urinary tract infection (UTI) is a major global infectious disease affecting millions of people annually. Human urinary copper (Cu) content is elevated during UTI caused by uropathogenic Escherichia coli (UPEC). UPEC upregulates the expression of Cu efflux genes during clinical UTI in patients as an adaptive response to host-derived Cu. Whether Cu is mobilized to urine as a host response to UTI and its role in protection against UTI remain unresolved. To address these questions, we tested the hypothesis that Cu is a host effector mobilized to urine during UTI to limit bacterial growth. Our results reveal that Cu is mobilized to urine during UTI caused by the major uropathogens Proteus mirabilis and Klebsiella pneumoniae, in addition to UPEC, in humans. Ceruloplasmin, a Cu-containing ferroxidase, is found at higher levels in UTI urine than in healthy control urine and serves as the molecular source of urinary Cu during UTI. Our results demonstrate that ceruloplasmin decreases the bioavailability of iron in urine by a transferrin-dependent mechanism. Experimental UTI with UPEC in nonhuman primates recapitulates the increased urinary Cu content observed during clinical UTI. Furthermore, Cu-deficient mice are highly colonized by UPEC, indicating that Cu is involved in the limiting of bacterial growth within the urinary tract. Collectively, our results indicate that Cu is a host effector that is involved in protection against pathogen colonization of the urinary tract. Because urinary Cu levels are amenable to modulation, augmentation of the Cu-based host defense against UTI represents a novel approach to limiting bacterial colonization during UTI. KEYWORDS UTI, urinary tract infection, uropathogenic E. coli, UPEC, copper, ceruloplasmin U rinary tract infection (UTI) is an extremely common infectious disease in the UnitedStates and around the world (1, 2). In the United States alone, UTI leads to 11 million physician visits, 1.7 million emergency room visits, and 470,000 hospitalizations annually, with a direct cost of $3.5 billion (2). Infection of the urinary bladder (cystitis) is the most common form of UTI, whereas kidney infection (pyelonephritis), bacteremia, and sepsis are less common but more serious outcomes of UTI (3, 4). Women are four times as likely to develop UTI as men are because of anatomic differences (4). Children, the elderly, and individuals with catheters, anatomic and physiologic abnormalities of the urinary tract, uroliths, or diabetes mellitus are also highly susceptible to UTI (4).Uropathogenic Escherichia coli (UPEC) is the etiological agent in ϳ85% of the cystitis cases in otherwise healthy people (3). Free-living, adherent, biofilm, and intracellular forms of UPEC are found in the urinary bladder (5, 6). UPEC utilizes multiple virulence factors, including type 1 fimbriae, P fimbriae, flagella, toxins, and iron acquisition systems, to cause UTI (2, 7). In addition to UPEC, Klebsiella pneumoniae and Proteus

Silver nanoparticles (AgNPs) show promise for treatment of aggressive cancers including triple‐negative breast cancer (TNBC) in preclinical cancer models. For clinical development of AgNP‐based therapeutics, it will be necessary to clearly define the specific physicochemical features of the nanoparticles that will be used, and to tie these properties to biological outcomes. To fill this knowledge gap, we performed thorough structure/function, mechanistic, safety, and efficacy studies to assess the potential for AgNPs to treat TNBC. We establish that AgNPs, regardless of size, shape, or stabilizing agent, are highly cytotoxic to TNBC cells at doses that are not cytotoxic to non‐malignant breast epithelial cells. In contrast, TNBC cells and non‐malignant breast epithelial cells are similarly sensitive to exposure to silver cation (Ag+), indicating that the nanoparticle formulation is essential for the TNBC‐specific cytotoxicity. Mechanistically, AgNPs are internalized by both TNBC and non‐malignant breast cells, but are rapidly degraded only in TNBC cells. Exposure to AgNPs depletes cellular antioxidants and causes endoplasmic reticulum stress in TNBC cells without causing similar damage in non‐malignant breast epithelial cells. AgNPs also cause extensive DNA damage in 3D TNBC tumor nodules in vitro, but do not disrupt the normal architecture of breast acini in 3D cell culture, nor cause DNA damage or induce apoptosis in these structures. Lastly, we show that systemically administered AgNPs are effective at non‐toxic doses for reducing the growth of TNBC tumor xenografts in mice. This work provides a rationale for development of AgNPs as a safe and specific TNBC treatment.

No abstract