Copper nanoparticles are embedded into a solvothermally grown thin film of a zirconium metal-organic framework (MOF), NU-1000, by installing single-site Cu(II) into the NU-1000 thin film via ...solvothermal deposition in MOFs (SIM) followed by electrochemical reduction of Cu(II) to metallic Cu. The obtained Cu nanoparticles are electrochemically addressable and exhibit promising electrocatalytic activity for CO2 reduction in an aqueous electrolyte.
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IJS, KILJ, NUK, PNG, UL, UM
The prevalence of toxic chemicals, ranging from chemical warfare agents (CWAs) to toxic industrial chemicals (TICs), emphasizes the importance of developing materials that can address these threats ...to both humanity and the environment. Polymers of intrinsic microporosity (PIMs) have emerged as a class of porous materials with tunable reactivity that are capable of answering this call. In this work, we leveraged the excellent processability of the PIM-1 family of polymers to fabricate porous fibrous mats using electrospinning. Following extensive structural characterization, we demonstrate that these reactive fibers are capable of both detoxifying an organophosphorus CWA simulant and capturing the TIC SO2, paving the way towards the implementation of these reactive materials in practical next-generation protective applications.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
Defect engineering proves to be a highly effective approach for introducing additional open metal sites and porosity into metal–organic frameworks (MOFs), thereby enhancing their gas storage, ...separation, and chemical catalysis capabilities. However, characterizing defective MOFs, which often exhibit nonuniform pores, presents a significant challenge. While probe molecules have been widely utilized to explore the physical and chemical properties of MOF pores, their application has predominantly been limited to gas- or vapor-phase molecules. In this study, we present a novel approach by employing a size-selective fluorescent protein probe to characterize macroporous defects induced by tartaric acid in a zirconium-based MOF, NU-1000. The spatial visualization of defects using a hemoglobin-based fluorescent probe allows for the identification of distinct structural weak points and defect formation mechanisms in NU-1000 crystallites prepared by various methods. In addition to confirming findings from conventional MOF characterization methods, such as gas sorption isotherms and powdered X-ray diffraction analysis, the hemoglobin-based protein probe unveils structural nuances overlooked by many traditional characterization techniques.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
Background: The use of laparoscopic surgical procedures without previous training has grown rapidly. At the same time, there have been allegations of increased complications among less experienced ...surgeons.
Methods: Using multivariate regression analyses, we evaluated the relationship between bile duct injury rate and experience with laparoscopic cholecystectomy for surgeons in the Southern Surgeons Club.
Results: Fifty-five surgeons performed 8,839 procedures. Fifteen bile duct injuries (by 13 surgeons) resulted with 90% of the injuries occurring within the first 30 cases performed by an individual surgeon. Multivariate analyses indicated that the only significant factor associated with an adverse outcome was the surgeon's experience with the procedure. A regression model predicted that a surgeon had a 1.7% chance of a bile duct injury occurring in the first case and a 0.17% chance of a bile duct injury at the 50th case.
Conclusions: While surgeons appear to learn this procedure rapidly, institutions might consider requiring surgeons to move beyond the initial learning curve before awarding privileges.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Crystalline materials undergo valuable phase transformations, and the energetic processes that underlie these transformations can be fully characterized through a combination of thermodynamic and ...kinetic studies. Here, we report the first complete reaction energy landscape of metal–organic framework (MOF) interpenetration, specifically in the phase transformation of NU-1200 to its doubly interpenetrated counterpart, STA-26. We characterized the thermodynamics of this phase transformation by pairing experiments with density functional theory (DFT) calculations. This analysis revealed that factors such as the increase in crystal density likely drive Zr- and Hf-NU-1200 to STA-26 interpenetration, while other chemical interactions such as steric repulsions prevent Th-NU-1200 from interpenetrating. Using time-resolved in situ X-ray diffraction, we monitored phase transformation reaction profiles and extracted quantitative kinetic information using the Avrami-Erofe’ev model. As a result, we obtained activation energies for the Zr- and Hf-NU-1200 transformations to Zr- and Hf-STA-26, respectively, revealing slower phase change kinetics for MOFs with stronger bonds. Finally, we paired the kinetic data with experimental observations to classify the mechanistic model of this phase transformation as partial dissolution. We anticipate that this thermodynamic, kinetic, and mechanistic understanding will broadly inform further studies on the energetics of crystallization.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
With the broad applicability of wireless sensor networks across fields, it is desirable to develop self-describing sensor nodes that can operate in a plug-n-play manner. In this paper, we present ...MoteML, a metadata encoding suitable for storage on memory-constrained devices, designed in support of this goal. MoteML is consistent with Sensor Web Enablement's 23 Sensor Model Language (SensorML). More specifically, while MoteML does not conform to the SensorML schema, it can be translated into SensorML and vice-versa. This paper explores the available solutions for storing self-describing information on memory-constrained sensor nodes and presents the design of MoteML. MoteML is a text-based encoding that captures a subset of SensorML in a template-based structure. This text data is then compressed using available text compression techniques. The resulting file is small enough to be stored on a memory-constrained embedded device.
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