Active Pd Research Articles

Effect of Electric Field on Carbon Encapsulation and Catalytic Activity of Pd for Efficient Formic Acid Decomposition

Utilizing carbon coated ferroelectric materials to introduce polarization‐induced electric field (PIEF) stimulates research of electric field‐assisted catalysts for various reactions. However, effect of PIEF on carbon coating mechanism has not been studied. Herein, tourmaline nanoparticles (TNPs) with spontaneous dipole moments were applied as the PIEF supplier and sucrose was utilized as the carbon precursor to synthesize carbon coated TNPs (TNP@SC) to uncover the influence of PIEF on the carbon coating and catalytic activity of Pd toward formic acid decomposition (FAD). PIEF enhanced the adsorption capacity of TNPs for the caramelized intermediate species and increased H+ concentration by facilitating water ionization. Polymerization of adsorbed caramelized intermediate species on TNPs was accelerated. Uniformly coated carbon layer with more defects, larger specific surface area, and higher porosity was coated on TNP. Such surface properties of the carbon layer were beneficial for strongly anchoring ultrafine Pd nanoparticles. Owing to the specific properties of carbon layer and existence of PIEF, Pd/TNP@SC exhibited higher FAD activity than the catalysts absent of PIEF. Stronger PIEF leaded to higher initial turnover frequency. This study provides guidance to supply electric field for catalysis.

Palladium–platinum bimetallic modified MXene nanozyme for highly sensitive detection of active substances with acetylcholinesterase inhibitory effect

Alzheimer's disease (AD) is a chronic neurodegenerative disease that threatens to the health of global elderly population. Acetylcholinesterase (AChE) inhibitors are an effective therapeutic agent for AD, and screening of these substances is important for AD treatment. In this work, a Pd–Pt MXene nanoenzyme was successfully synthesized by using the in-situ reduction technique. A colorimetric method for sensitive AChE inhibitor detection was designed based on enzymatic cascade reaction between Pd–Pt MXene and AChE. Briefly, The Pd–Pt MXene material exhibited excellent peroxidase (POD)-like activity due to its bimetallic composition, effectively catalyzing the oxidation of colorless 3,3,5,5-tetramethylbenzidine (TMB) to generate blue oxidized TMB (oxTMB). Under the presence of AChE and acetylthiocholine chloride (ATCh), the POD-like activity of Pd–Pt MXene was significantly inhibited. The activity of this nanoenzyme could be restored after the addition of AChE inhibitors. Using donepezil as an example, colorimetric detection was conducted within a linear range of 0.1 nmol/L to 10 nmol/L and the lowest detection boundary was only 0.35 nmol/L (S/N = 3). Finally, a paper-based platform was designed and constructed, and it has been successfully employed for AChE inhibitor detection in real samples with the aid of a smartphone. In all, this work paves a new way for designing nanoenzyme-based devices towards medicine determination or screening like AChE inhibitor.

451 (PB439): First results of a Phase 1 study evaluating safety, PK, PD and clinical activity of STC-15, aMETTL3 inhibitor, in patients with advanced malignancies

451 (PB439): First results of a Phase 1 study evaluating safety, PK, PD and clinical activity of STC-15, aMETTL3 inhibitor, in patients with advanced malignancies

The photophysical, photobiological, and light-up calf-thymus-DNA sensor activity of Pd(II) and Pt(II) polypyridyl derivatives coordinated to vinyl-pyridyl corroles

A series of mono-cationic corroles containing bipyridyl derivatives coordinated with Pd(II) and Pt(II) polypyridyl complexes is reported here. These corroles were characterized by microanalysis, UV–Vis absorption, steady-state and time-resolved fluorescence emission, theoretical DFT calculations, and electrochemical techniques. Photobiological parameters, such as photostability and ROS production, were also assessed. Spectroscopic and viscometry studies, along with molecular docking calculations, revealed each corrole derivative's ability to interact with the minor grooves of calf-thymus DNA. Additionally, the potential of these derivatives to act as emissive optical sensors for CT-DNA was evaluated.

Synthesis and anticancer activity of Pd(II) and Pt(II) complexes of dodecyl based dithiocarbamate ligands: Insight into the C-H∙∙∙Pt interaction using X-ray structure, DFT, Hirshfeld surface and AIM analysis

Four new homoleptic complexes bis(N-dodecyl-N-benzyl)dithiocarbamato-S,S’)M(II) (where M=palladium (1), platinum (3)) and bis(N-dodecyl-N-(2-hydroxybenzyl)dithiocarbamato-S,S’)M(II) (where M=palladium (2), platinum (4)) were synthesized and characterized using elemental analysis, FTIR and NMR spectra. The crystal structures of 1 and 4 were solved by single crystal X-ray diffraction technique. Single crystal X-ray analysis of the two of the complexes (1 and 4) revealed the presence of a distorted square planar coordination geometry (S4) about the metal centre. Complex 4 revealed two intermolecular anagostic C-H∙∙∙Pt interactions which were characterized through a comprehensive set analysis using single crystal X-ray diffraction (experimental) and DFT, Hirshfeld surface analysis and AIM (theoretical) analysis. The electronic behavior, MEP surfaces, FMO and DOS studies of the complexes 1 and 4 were investigated employing DFT. A strong correlation has been found between both experimental and theoretical bond parameters. MTT assay was used to study the antitumor activities of 1–4 against MCF7 cancer cells. The results reveal that all complexes have fine anticancer activities.

High N2-selectivity of nitrite reduction by palladium-laden nanocomposite with self-sufficient electron donators

Selectively reducing nitrite to gaseous nitrogen (N2) with an effective and recyclable fashion stands as an attractive alternative for treating the relevant wastewater. Herein, a Pd-based nanocomposite (Pd@EDA-CMPS) was subtly assembled by encapsulating Pd(0) nanoparticles into a porous polystyrene carrier, which was aforehand functionalized with ethylenediamine (EDA) as the endogenous electron donator. Systematical macroscopic experiments confirm that the pre-grafted EDA groups can substantially stimulate the catalytic activity of the laden Pd(0) nanoparticles with high removal efficiency and N2 selectivity of Pd@EDA-CMPS toward nitrite; specifically, high N2 selectivity (86%) was achieved by Pd@EDA-CMPS with an excellent anti-interference ability against competing anion and a broad pH-range applicability (4–11), whereas no N2 production was detected for its counterparts (CMPS, EDA-CMPS, and Pd@CMPS). Spectroscopic analyses reveal that the grafted EDA groups played a decisive role in the formation of H-loaded Pd(0) nanoparticles inside the porous substrate, which joint with the unique pH-buffering ability of EDA drove the reaction to the production of nitrogen (N2) rather than ammonia (NH3). The exhausted Pd@EDA-CMPS can be promisingly regenerated by NaOH (eluting) and NaBH4 (restoring) solution without obvious loss in treatment capacity and N2 selectivity. This work provides a feasible strategy for catalytically reducing nitrite into N2 without the provision of exogenous reductor such as hydrogen.

From Precious to Earth-Abundant Metallic Nanoparticles: A Trend of Interband Transitions in Photocatalyzed Nitrobenzene Reduction.

Metallic nanoparticles have been demonstrated to be versatile photocatalysts, as exemplified by those made from noble and precious metals. Transitioning from precious to earth-abundant metals for sustainable photocatalysis requires benchmarking their catalytic performance. In this work, we attempt to compare the photocatalytic activities of Au, Pd, and Co-B nanoparticles in the reduction of nitrobenzene by hydrazine. Despite their different morphologies and surface structures, Co-B nanoparticles offer the highest catalytic enhancement when comparing their reaction rates under irradiation to those under nonirradiation conditions. The trend of improved photocatalytic performance when transitioning from Au to Pd, and then to Co-B, can be explained by the nature of their d-band positions and corresponding hot carriers photogenerated from interband transitions.

Flexible Wearable Chemoresistive Ethylene Gas-Monitoring Device Utilizing Pd/Ti3C2Tx Nanocomposites for In Situ Nondestructive Monitoring of Kiwifruit Ripeness.

Kiwifruit, renowned for its antioxidant properties and nutritional richness, faces challenges in maintaining quality during transportation, often leading to suboptimal products reaching the market. To address this issue, a wireless transmission flexible ethylene monitoring device (WFEMD) was developed. This device comprises a flexible ethylene gas sensor and a signal transmission processing unit integrated with electronic components, enabling real-time monitoring capabilities. In this study, the catalytic activity of Pd and Pd/Ti heterojunctions was leveraged to enhance the ethylene gas sensing. The impact of Ti3C2Tx modified with varying masses of Pd nanoparticles on ethylene gas response levels was investigated. The signal transmission processing unit, fabricated by using the laser direct-writing method, was optimized to collect signals from the flexible ethylene gas sensor, convert them into corresponding ethylene concentrations, and transmit data via an antenna. By introducing a random forest (RF) classification algorithm, a remarkable 97.5% accuracy in predicting kiwifruit ripeness grades was achieved. The algorithm facilitated precise classification by collecting key parameters such as ethylene and CO2 during transportation. The WFEMD enables real-time acquisition of kiwifruit ethylene gas information, which is transmitted wirelessly for data visualization and traceability via mobile terminals. This empowers managers with timely insights into ethylene emissions and ripeness predictions, facilitating informed decision-making processes.

Enhancing collaboration of anammox with heterotrophic microbes mediated selectively by iron of different valences: Activities balance, metabolic mechanism, and functional genes regulation

The partial denitrification/anammox (PD/A) process is receiving increasing attention due to its cost-effectiveness advantages. However, effective strategies to alleviate organic matter inhibition and promote anammox activity have been proven to be a big challenge. This study investigated the effects of three types of iron (nano zero-valent iron (nZVI), Fe(II), and Fe(III)) on the PD/A process. It is worth noting that nZVI of 5–50 mg/L and Fe(III) of 5–120 mg/L promoted both PD and anammox activity. Long-term intermittent addition of nZVI (50 mg/L) resulted in a nitrogen removal efficiency of 98.2% in the mixotrophic PD/A system driven by iron and organic matter. The contribution of anammox for nitrogen removal reached as high as 93.8%. The organic carbon demand decreased due to the external electron donor provided by nZVI for PD. Multiple Fe–N metabolic pathways, primarily involving ammonia oxidation by Fe(III) and nitrate reduction by nZVI, play a crucial role in facilitating nitrogen transformation. Conversely, the direct addition of 30–120 mg/L Fe (II) resulted in a significant decrease in pH to below 5.0 and severe inhibition of PD and anammox activity. Following prolonged operation in the presence of nZVI, it was demonstrated that there is an enhancing effect on robust nitrite production for anammox. This was accompanied by a remarkable up-regulation of genes encoding nitrate reductase and iron-transporting proteins dominated by Thauera. Overall, this study has provided an efficient approach for advanced nitrogen removal through organic- and iron-driven anammox processes.

Investigation of Partial Discharge Transformation Characteristics in Polyimide (PI) Insulations under High-Frequency Electric Stress.

This research delves into the primary issue of polyimide (PI) insulation failures in high-frequency power transformers (HFPTs) by scrutinizing partial discharge development under high-frequency electrical stress. This study employs an experimental approach coupled with a plasma simulation model for a ball-sphere electrode structure. The simulation model integrates the particle transport equation, Poisson equation, and complex chemical reactions to ascertain microscopic parameters, including plasma distribution, electric field, electron density, electron temperature, surface, and space charge distribution. The effect of the voltage polarity and electrical energy on the PD process is also discussed. The contact point plays a pivotal role in triggering partial discharges and culminating in the breakdown of PI insulation. Asymmetry phenomena were found between positive and negative half-cycles by analyzing the PD data stage by stage. A significant number of PDs increased at every stage and the PD amplitude was higher during the negative cycle at the initial stage, but in later stages, the PD amplitude was found to be higher in the positive half-cycle, and scanning electron microscopy (SEM) revealed that the maximum damage occurred near the contact point junction. The simulation results show that the plasma initially accumulates the electron density near the contact point junction. Under the action of the electric field, plasma starts traveling at the PI surface outward from the contact point. Before the PD activity, all parameters have higher values in the plasma head. The microscopic parameters reveal maximum values near the contact point junction, during PD activities where significant damage takes place. These parameter distributions exhibit a decreasing trend over time as when the PD activity ends. The model's predictions are consistent with the experimental data. The paper lays the foundation for future research in polymer insulation design under high-frequency electrical stress.

Pd(II), Pt(II), and novel Hg(II) metal complexes of N-(diphenylphosphinothioyl)-2-(4-methylpyridyl) amine chelating ligand: Synthesis, characterization, X-ray structures and catalytic activity of Pd(II) derivative in the Suzuki cross-coupling reaction

The reaction of monooxidized thioyl (4-CH3)C6H3N-2-NH(P(S)Ph2) (1) ligand with MCl2(COD)(M = Pd, Pt) in equimolar ratio resulted in cis-[MCl2{1-κ2S,Npy}] (M = Pd (2), Pt(3)) complexes. Also, The reaction of 1 with HgX2 (X = Cl, I) produced cis-[HgX2{1-κ2S,Npy }] (X = Cl(4), I(5)). Complexes 2–5 have been isolated and characterized by multinuclear NMR (1H, 13C, and 31P) and IR spectroscopy. The molecular structures of 2, 4, and 5 were determined using single X-ray crystallography. 4 and 5 are the first structurally defined instances of this type of κ2S,Npy -bidentate ligand with Hg(II) metal complexes. The new palladium(II) complex 2 as a pre-catalyst in the Suzuki cross-coupling process was also investigated.

The design of nano-porous photocatalytic intermediate layer to fabricate the copper layer on AlN ceramic with high bonding strength through the interlocking microstructure

AlN ceramic is the potential substrate for high-performance printed circuit board with the rapid development of electronic industry due to the superior thermal and electrical property, while its metallization still faces the issues of thermal stress and weak interface bonding with existing technology. Herein, a convenient design is proposed to achieve the Cu deposition on the surface of AlN substrate, the TiO2 containing photocatalytic intermediate layer is prefabricated on AlN substrate with silica and titania mixed sol, and induces the autocatalytic deposition of electroless copper plating under ultraviolet irradiation. Compared with Cu deposition with Pd activation treatment, the bonding strength between Cu layer and AlN substrate is significantly enhanced with the intermediate layer, this is ascribed to the formed nano-porous microstructure of the sintered intermediate layer facilitating the penetration of plating bath, and the mechanical anchoring effect derived from the interlocking microstructure between Cu layer and intermediate layer contributes to the improved bonding strength. This new method realizes the metallization of AlN ceramic with high interfacial bonding strength and low cost compared with the traditional joining technology, and provides a potential reference for the surface metallization of inert material.

Antitumor Activity of New Pd(II) Complexes with Ligands Derived from O‐Vanillin Acting as Topoisomerase I and II Inhibitors

AbstractThis study investigates topoisomerase I and II enzyme inhibition by novel Pd(II) complexes. TSC represents the chelating ligand thiosemicarbazone, which is modified at its 4(N)‐nitrogen terminal position with substituents such as C2H5, CH3, and H. PR3 represents the triphenylphosphine ligand, with positional variations including para substituents H, F, OCH3, and CH3. The aim is to establish a correlation between these molecular variations and cytotoxicity. In particular, the compounds show promising cytotoxicity against MDA‐MB‐231 and A549 tumor cell lines, especially those with H substitution at the terminal position 4(N) of TSC and H and F in the triphenylphosphine. The results suggest that a smaller molecular volume of ligand substituents may enhance the cytotoxic effects. The inhibitory potential of the complexes against DNA topoisomerase enzymes was investigated. The IC₅₀ values of the most promising complexes strongly inhibit TOPOIIα and TOPOIβ, suggesting these enzymes as primary targets. These complexes exhibited significantly lower IC₅₀ values (4.32–4.88 μM) compared to cisplatin (10.2 μM) against MDA‐MB‐231 cells, indicating a distinct mode of action. However, it is noteworthy that the complexes did not inhibit the action of DNA topoisomerase IIβ, suggesting selectivity against specific isoforms of DNA topoisomerase II that act as catalytic inhibitors.

Synthesis, characterization and the catalytic application of the N-heterocyclic carbene-PdCl2-cyanopyridine complexes

Six monoligated N-heterocyclic carbene-PdCl2-cyanopyridine complexes were prepared (N-heterocyclic carbene = NHC). X-ray single crystal diffraction analysis indicated that the complexes showed mononuclear Pd–NHC structures with two chlorides and the N-donor from cyanopyridine as ancillary ligands. The lengths of the Pd–C bonds in all complexes were 1.959(5)–1.976(3) Å, comparable to those found in the corresponding Pd–NHC catalysts. The catalytic activities of the well-defined Pd–NHC complexes have been evaluated with respect to the Hiyama cross-coupling reactions of aryl trialkoxysilanes with aryl chlorides. With 1.0 mol% Pd-catalyst, all synthesized palladium compounds have shown moderate to good catalytic activities for the coupling reactions.

Enzyme Mimetic Activity of Intercalated Pd–H Nanosheets for Bioanalysis

Enzyme Mimetic Activity of Intercalated Pd–H Nanosheets for Bioanalysis

Bond strength of epoxy-based composites at the interface with surface deposited metal layer: A comparative study with different dimensional fillers

With the complexity of the working environment, pure epoxy resin can no longer meet the requirements, and the weak interfacial bonding between metal layer and epoxy-based composites limits its development. In this work, we propose a novel molecular grafting modification technique by using the active functional groups of polymers, which can apply to epoxy-based composites with various fillers to improve the adhesive strength of the interface between the metal film and matrix. 3D surface profile and surface wettability were used to characterize the effect of fillers on the surface of epoxy composites. Scanning electron microscope (SEM) and Raman spectroscopy were utilized to judge the interface failure modes of the composites. Peeling test and surface-enhanced Raman scattering (SERS) were conducted to examine how fillers affected adhesion. The results showed that silane grafting substantially improved the bonding between the epoxy-based composite matrix and the metal layer without the need for alkaline washing and palladium (Pd) activation steps on the substrate. The average adhesive strength can reach a maximum of 17.76 N/cm. The study also revealed the effect of filler size on the interfacial adhesive strength. The interfacial adhesive strength was increased by two dimensional lamellar materials, decreased by one-dimensional tubular materials, and remained unaffected by zero-dimensional spherical materials. This study may have positive implications for improving interfacial bonding between metal and polymer composite surfaces.

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A randomized phase II trial of adjuvant pembrolizumab versus observation following curative resection for stage I non-small cell lung cancer (NSCLC) with primary tumors between 1-4 cm: Big Ten Cancer Research Consortium BTCRC-LUN18-153.

TPS8118 Background: Each year, approximately 35,000 patients are diagnosed with stage I lung cancer in the United States. Despite early detection, the 5-year overall survival for this population remains disappointing, ranging between 73-86% with recurrence rates from 18-38%. The current standard of care for stage I NSCLC is surgery alone followed by observation as prior trials of adjuvant chemotherapy in this subgroup have failed to show benefit. More modern therapies such as programmed death-1 (PD-1) inhibitors have not been evaluated in the stage I setting but have demonstrated significant improvements in pathologic complete response, event free survival, and overall survival when added to chemotherapy for patients with fully resected stage II and III disease. The use of PD-(L)1 inhibition has also demonstrated clinically and statistically significant improvements in OS in both unresectable stage III NSCLC following chemoradiation and in the metastatic setting. Given the activity of PD-(L)1 inhibition in nearly every other subset of NSCLC patients, we aimed to evaluate this therapy following resection in stage I NSCLC patients. Methods: This study is a randomized phase II multicenter trial of adjuvant Pembrolizumab versus observation alone following complete resection of stage I NSCLC with tumors between 1-4cm. The trial randomizes patients 1:1 to either Pembrolizumab 400mg IV every 6 weeks for up to 9 cycles or observation alone. Patients are stratified by PD-L1 score (PD-L1 ≥50% vs. < 50%) and tumor size (1-2cm vs. > 2-4cm), and they undergo repeat CT imaging every 12 weeks. The study is being conducted through the Big Ten Cancer Research Consortium, and there are currently 11 sites open to accrual with one additional site pending activation. The primary endpoint is disease free survival with secondary endpoints including OS, DFS at multiple timepoints (1-, 2-, and 3-years), and safety. The trial initially opened to accrual at the lead site, Indiana University, in May 2020, and enrollment is currently at 95 patients with a planned enrollment of 244. (NCT04317534) Clinical trial information: NCT04317534 .

Effects of a DC Offset on Lifetime and PD Activity During AC Aging Tests on Enameled Twisted Pairs

Effects of a DC Offset on Lifetime and PD Activity During AC Aging Tests on Enameled Twisted Pairs

Phase 1 dose escalation and cohort expansion study evaluating safety, PK, PD and clinical activity of STC-15, a METTL-3 inhibitor, in patients with advanced malignancies.

2586 Background: RNA modifications are involved in cancer initiation and progression. The most abundant modification of mRNA is m6A generated by METTL3. Inhibition of METTL3 causes double-stranded RNA formation and activation of cellular T1 IFN response. IFN signaling induces IFN-stimulated gene families i.e. IFIT and OAS, characteristic of an anti-viral response, and secretion of cytokines and chemokines. STC-15, a first in class small molecule inhibitor of METTL3 developed by Storm Therapeutics, demonstrated in pre-clinical models, activation of IFN signaling and remodeling of the TME towards pro-inflammatory state. We report the dose escalation results from a FIH trial in patients with advanced malignancies. Methods: This is a multi-center, open-label, dose escalation study. STC-15 oral capsules are administered daily or t.i.w. in 21-d treatment cycles. Dose escalation follows 3+3 modified Fibonacci regimen. Primary objectives are safety and PK. Secondary objectives are preliminary evidence of anticancer activity and RP2D. Exploratory objectives are PD (i.e. target engagement and immune activation biomarkers) and correlation of primary pharmacology with observed clinical efficacy. Results: As of 02/01/2024, 31 patients enrolled across 4 dose levels and 5 cohorts: 60mg QD (6 pats), 60mg t.i.w. (3 pats), 100mg t.i.w. (14 pats), 160 mg t.i.w. (5 pats) and 200mg t.i.w. (3 pats). PK profile supports t.i.w. dosing. A total of 169 AEs were observed with 45 AEs attributed to STC-15 treatment. AEs were manageable, mostly hematology (thrombocytopenia 31%; 4% Grade 3), skin (pruritis, rash 14% G1/2) and GI (N/V and diarrhea 14% G1/2). 12 SAEs occurred; 1 pt (60mg QD) had DLT with G3 pneumonitis. Of 14 patients with at least 1 on-treatment scan, DCR is 78% with 2 confirmed PR ongoing in angiosarcoma (60mg, 32 weeks) and IO-refractory NSCLC (100mg, 33 weeks) and 9 SD. An average of 63% reduction in m6A on mRNA in peripheral blood within the first 24h post dosing was observed in 60mg cohorts, confirming target engagement. Whole blood Nanostring and pathway analysis of gene expression confirms upregulation of innate immune pathways (i.e. T1,2 IFN activation and anti-viral responses) as early as 8h after first dose and throughout the treatment cycle. Updated PK/PD and clinical data will be presented. Conclusions: Treatment with STC-15 is well tolerated across pharmacologically active dose range with encouraging signs of clinical activity. Early biomarker data provide proof of mechanism in target engagement, strong activation of innate immune responses and correlation of pharmacological activity with clinical response. The study is ongoing and expansion cohorts are underway to further evaluate PK/PD, safety and clinical efficacy at optimized pharmacologically active doses. Clinical trial information: NCT05584111 .