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1. Temperature shifts associated with bat arousals during hibernation inhibit the growth of Pseudogymnoascus destructans

   https://doi.org/10.1098/rsos.211986  

   Forney, Ronny; Rios-Sotelo, Gabriela; Lindauer, Alexa; Willis, Craig K.; Voyles, Jamie (November 2022, Royal Society Open Science)

   Temperature is a critically important factor in many infectious disease systems, because it can regulate responses in both the host and the pathogen. White-nose syndrome (WNS) in bats is a severe infectious disease caused by the temperature-sensitive fungus, Pseudogymnoascus destructans ( Pd ). One feature of WNS is an increase in the frequency of arousal bouts (i.e. when bat body temperatures are elevated) in Pd -infected bats during hibernation. While several studies have proposed that increased frequency of arousals may play a role in the pathophysiology of WNS, it is unknown if the temperature fluctuations might mediate Pd growth. We hypothesized that exposure to a high frequency of elevated temperatures would reduce Pd growth due to thermal constraints on the pathogen. We simulated the thermal conditions for arousal bouts of uninfected and infected bats during hibernation (fluctuating from 8 to 25°C at two different rates) and quantified Pd growth in vitro . We found that increased exposure to high temperatures significantly reduced Pd growth. Because temperature is one of the most critical abiotic factors mediating host–pathogen interactions, resolving how Pd responds to fluctuating temperatures will provide insights for understanding WNS in bats and other fungal diseases. 

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2. An environmentally responsible 3-pot, 5-step synthesis of the antitumor agent sonidegib using ppm levels of Pd catalysis in water

   https://doi.org/10.1039/c9gc03495a  

   Takale, Balaram S.; Thakore, Ruchita R.; Kong, Fan Yi; Lipshutz, Bruce H. (November 2019, Green Chemistry)

   The current industrial approach to sonidegib utilizes wasteful organic solvents and relies on high loadings of endangered Pd. This anticancer drug can now be synthesized in 5 steps using only 3 pots, along with ppm levels of a Pd catalyst, all done in water at ambient temperatures. 

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3. Impact of Flame Conditions on the Pd‐O Structure and Methane Oxidation Activity over Ceria Support

   https://doi.org/10.1002/cctc.202401449  

   Wang, Can; Najimu, Musa; Ko, Ben; Sasmaz, Erdem (October 2024, ChemCatChem)

   Abstract In this work, we employed flame spray pyrolysis (FSP), a high‐temperature synthesis method, to control the formation of Pd structures on the CeO₂support. Multiple types of Pd structures deposited on CeO₂are observed on FSP‐made samples. Our results show that the oxidizing environment during FSP synthesis facilitates the formation of incorporated Pd²⁺structures, along with highly dispersed Pd²⁺, Pd⁰nanoparticles, and Pd° clusters formed under the reducing synthesis condition. Notably, these Pd²⁺species remained stable at temperatures up to 400 °C. The catalysts containing both highly dispersed Pd²⁺nanoparticles and incorporated Pd²⁺species demonstrated superior methane oxidation activity, with higher turnover frequencies than those containing only one type of Pd²⁺structure. However, hydrothermal pretreatment in the presence of water vapor led to partial deactivation, likely due to structural alterations in the Pd species or the interaction with the CeO₂support, which reduced the stability and effectiveness of the active sites. This study underscores the importance of both highly dispersed and incorporated Pd²⁺species in enhancing catalytic performance and highlights the challenges posed by water‐induced deactivation in practical applications. 

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4. Reaction pathways for HCN on transition metal surfaces

   https://doi.org/10.1039/C8CP07548D  

   Abdel-Rahman, Mohammed; Feng, Xu; Muir, Mark; Ghale, Kushal; Xu, Ye; Trenary, Michael (February 2019, Physical Chemistry Chemical Physics)

   The adsorption and decomposition of HCN on the Pd(111) and Ru(001) surfaces have been studied with reflection absorption infrared spectroscopy and density functional theory calculations. The results are compared to earlier studies of HCN adsorption on the Pt(111) and Cu(100) surfaces. In all cases the initial adsorption at low temperatures gives rise to a ν (C–H) stretch peak at ∼3300 cm −1 , which is very close to the gas phase value indicating that the triple CN bond is retained for the adsorbed molecule. When the Pd(111) surface is heated to room temperature, the HCN is converted to the aminocarbyne species, CNH 2 , which was also observed on the Pt(111) surface. DFT calculations confirm the high stability of CNH 2 on Pd(111), and suggest a bi-molecular mechanism for its formation. When HCN on Cu(100) is heated, it desorbs without reaction. In contrast, no stable intermediates are detected on Ru(001) as the surface is heated, indicating that HCN decomposes completely to atomic species. 

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5. Palladium/cobalt nanowires with improved hydrogen sensing stability at ultra-low temperatures

   https://doi.org/10.1039/C9NR07834G  

   Du, Lingling; Feng, Dongliang; Xing, Xiaxia; Fu, Yang; Fonseca, Luis F.; Yang, Dachi (November 2019, Nanoscale)

   The metallic dopants in palladium (Pd) sensing materials enable modification of the d-band center of Pd, which is expected to tune the α–β phase transitions of the PdH x intermediate, thus improve the sensing stability to hydrogen. Here, the boosted hydrogen-sensing stability at ultra-low temperatures has been achieved with palladium/cobalt nanowires (PdCo NWs) as the sensing material. The various Co contents in PdCo NWs were modulated via AAO-template-confined electrodeposition. The temperature-dependent sensing evaluations were performed in 0.1–3 v/v% hydrogen. Such sensors integrated with PdCo NWs are able to stably detect hydrogen as low as 0.1 v/v%, even when the temperature is lowered to 273 K. In addition, the critical temperatures of “reverse sensing behavior” of the PdCo NWs (Pd 82 Co 18 : T c = 194 K; Pd 63 Co 37 : T c = 180 K; Pd 33 Co 67 : T c = 184 K) are observed much lower than that of pristine Pd NWs ( T c = 287 K). Specifically, the Pd 63 Co 37 NWs (∼37 at% Co content) sensor shows outstanding stability of sensing hydrogen against α–β phase transitions within the wide temperature range of 180–388 K, which is attributed to both the electronic interactions between Pd and Co and the lattice compression strain caused by Co dopants. Moreover, the “reverse sensing behavior” of the PdCo NWs is explicitly interpreted using the α–β phase transition model. 

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