Low Pd Research Articles

Choice between DNA primer sets (A or B) of the ForenSeq kit: forensic evaluation in a Mexican admixed population sample.

Massively parallel sequencing (MPS) overcomes many PCR-CE limitations to analyze STRs and allow simultaneous inclusion of SNPs in forensic cases. By MPS, the ForenSeq™ DNA Signature Prep kit analyzes 27 aSTRs, 7 X-STRs, 24Y-STRs, and 94 identity-informative SNPs (iiSNPs) with the DNA Primer Set-A (DPS-A). Optionally, the DNA Primer Set-B (DPS-B) adds to the analysis 56 ancestry-informative SNPs (aiSNPs) and 24 phenotype-informative SNPs (piSNPs), but diminishes from 96 to 32 the number of samples per sequencing run. We assessed the forensic informativity provided by the loci analyzed by these two DPS in admixed individuals from Mexico City (Center, Mexico). For STRs, we report length-based (LB) and sequence-based (SB) allele frequencies and forensic parameters of the 152 identity informative markers (DPS-A). For aSTRs, the combined PD of SB genotypes (PD ~ 100%) was ~ 2949 times larger than that from LB. Conversely, the observed phenotype distribution offered low PD levels (PD = 6.6% and 10.4%), whereas piSNPs predicted accurately only the modal brown eye and dark hair colors, respectively. Similarly, aiSNPs detected a large prevalence of admixed individuals (97.3%; PD = 5.4%). Although few individuals were inferred as Europeans and Native Americans (1.37% each), they were self-declared as admixed, which result confusing for HID purposes. In brief, SB genotypes increased significantly the informativity of STRs to solve complex cases (DPS-A), whereas aiSNPs and piSNPs added mostly irrelevant information (DPS-B). We provide useful cost-benefit criteria in one Latin American population to choose DPS-A (96 samples) instead of DPS-B (32 samples) of the Forenseq kit.

Pd modified by Fe-Nx confined in N-doped carbon with hierarchical mesoporous structure for the highly efficient semi-hydrogenation of phenylacetylene

The removal of small amounts of phenylacetylene from styrene is a crucial step in the production of high-quality styrene feedstocks. In the presence of a large amount of styrene and a small amount of phenylacetylene, achieving and maintaining high selectivity of styrene remains a significant challenge. In this work, a catalyst denoted as Pd1.25-Fe-N-C/VC was designed and synthesized with remarkably low Pd loading (the actual Pd content was 0.96 wt%). The catalyst exhibited a satisfactory selectivity for styrene (>95 %) and maintained high selectivity levels (>90 %) in the semi-hydrogenation of phenylacetylene even with prolonged reaction time. Pd nanoparticles (NPs) were well distributed and securely anchored onto the Fe-N-C/VC support with a hierarchical mesoporous structure, which obtained from the pyrolysis of a hexagonal star-like Fe-doped zeolitic imidazolate framework with vitamin C surfactant (Fe-doped ZIF/VC). The remarkable catalytic properties may be partly ascribed to the effective synergy effect of the uniformly well-dispersed Fe-Nx (x represents the coordination number) with Pd active centers, which could modulate the adsorption kinetics of the reactant alkynes and alkenes and thus enhancing the selectivity towards styrene. Meanwhile, the hierarchical mesoporous structure is beneficial for the mass transfer, which can effectively promote the interactions between the reactants and active centers. Possible mechanism for the selective hydrogenation of phenylacetylene catalyzed by Pd1.25-Fe-N-C/VC was also illustrated. Moreover, the Pd1.25-Fe-N-C/VC catalyst exhibited sustained catalytic activity and selectivity even after four continuous cycle tests, showing notable reusability and stability. This work may offer a promising approach for creating highly efficient Pd-based catalysts with remarkably low Pd loading for phenylacetylene semi-hydrogenation.

Change of composition and surface plasmon resonance of Pd/Au core/shell nanoparticles triggered by CO adsorption.

Controlling composition and plasmonic response of bimetallic nanoparticles (NPs) is of great relevance to tune their catalytic activity. Herein, we demonstrate reversible composition and plasmonic response transitions from a core/shell to a bimetallic alloyed palladium/gold NP triggered by CO adsorption and sample temperature. The use of self-organized growth on alumina template film allows scrutinizing the impact of core size and shell thickness onto NP geometry and plasmonic response. Topography, molecular adsorption, and plasmonic response are addressed by scanning tunneling microscopy, vibrational sum frequency generation (SFG) spectroscopy, and surface differential reflectance spectroscopy, respectively. Modeling CO dipolar interaction and optical reflectivity corroborate the experimental findings. We demonstrate that probing CO adsorption sites by SFG is a remarkably sensitive and relevant method to investigate shell composition and follow in real-time Pd atom migration between the core and the shell. Pd-Au alloying is limited to the first two monolayers of the shell and no plasmonic response is found, while for a thicker shell, a plasmonic response is observed, concomitant with a lower Pd concentration in the shell. Above 10-4mbar, at room temperature, CO adsorption triggers the shell restructuration, forming a Pd-Au alloy that weakens the plasmonic response via Pd migration from the core to the shell. NP annealing at 550K, after pumping CO, leads to the desorption of remaining CO and gives enough mobility for Pd to migrate back inside the core and recover a pure gold shell with its original plasmonic response. This work demonstrates that surface stoichiometry and plasmonic response can be tuned by using CO adsorption and NP annealing.

Pd-imidate@SBA-15: a multifunctional heterogeneous catalyst for the aqueous room temperature hydrogenation of CO2 to formic acid.

The incorporation of hydrophilic and basic sites from phosphotriazaadamantane and saccharine in a water-soluble Pd complex and the subsequent confinement into mesoporous silica support increases the activity and stability of the palladium catalytic species for the room-temperature aqueous hydrogenation of either bicarbonate or CO2 into formic acid. The use of low Pd loadings (<0.1mmolPd·g-1) of the well-dispersed complex on SBA-15 mesoporous silica allows performing the reaction under room temperature, and aqueous conditions, exhibiting TON of ca. 40-100, for the CO2 or bicarbonate hydrogenation, respectively, which is one order of magnitude higher than the homogeneous case, allowing the easy isolation and recycling of the solid catalyst.

Morphology-dependent support effect of PdCu/alpha-Fe2O3 catalysts on Suzuki-Miyaura cross-coupling reaction

The palladium-catalyzed Suzuki-Miyaura cross-coupling (SMC) reaction has received worldwide attention as a powerful and convenient synthetic tool for the formation of biaryl compounds. However, these reactions are highly dependent on the activity and stable of catalysts. Herein, the support morphology-dependent catalytic performance of SMC reactions was investigated. The truncated hexagonal bipyramid (α-Fe2O3-O) and rod-shaped morphologies of alpha-Fe2O3 (α-Fe2O3-R) were used as support to prepare PdCu nanoparticles (NPs) catalysts by NaBH4 reduction method. For PdCu/α-Fe2O3-R catalysts, the smaller size of PdCu NPs and more low coordination Pd sites leading to its superior catalytic performance for SMC reactions. Furthermore, it can be easily recycled through centrifugation and reused several times without obvious loss on its catalytic performance. Identical location transmission electron microscopy method was used to investigate the structural evolution of PdCu/α-Fe2O3-R catalysts. The results found that its structure almost unchanged during the catalytic reaction.

Au@AuPd Core-Alloyed Shell Nanoparticles for Enhanced Electrocatalytic Activity and Selectivity under Visible Light Excitation.

Plasmonic catalysis has been employed to enhance molecular transformations under visible light excitation, leveraging the localized surface plasmon resonance (LSPR) in plasmonic nanoparticles. While plasmonic catalysis has been employed for accelerating reaction rates, achieving control over the reaction selectivity has remained a challenge. In addition, the incorporation of catalytic components into traditional plasmonic-catalytic antenna-reactor nanoparticles often leads to a decrease in optical absorption. To address these issues, this study focuses on the synthesis of bimetallic core@shell Au@AuPd nanoparticles (NPs) with ultralow loadings of palladium (Pd) into gold (Au) NPs. The goal is to achieve NPs with an Au core and a dilute alloyed shell containing both Au and Pd, with a low Pd content of around 10 atom %. By employing the (photo)electrocatalytic nitrite reduction reaction (NO2RR) as a model transformation, experimental and theoretical analyses show that this design enables enhanced catalytic activity and selectivity under visible light illumination. We found that the optimized Pd distribution in the alloyed shell allowed for stronger interaction with key adsorbed species, leading to improved catalytic activity and selectivity, both under no illumination and under visible light excitation conditions. The findings provide valuable insights for the rational design of antenna-reactor plasmonic-catalytic NPs with controlled activities and selectivity under visible light irradiation, addressing critical challenges to enable sustainable molecular transformations.

Micro-Structure Engineering in Pd-InOx Catalysts and Mechanism Studies for CO2 Hydrogenation to Methanol.

Significant interest has emerged for the application of Pd-In2O3 catalysts as high-performance catalysts for CO2 hydrogenation to CH3OH. However, precise active site control in these catalysts and understanding their reaction mechanisms remain major challenges. In this investigation, a series of Pd-InOx catalysts were synthesized, revealing three distinct types of active sites: In-O, Pd-O(H)-In, and Pd2In3. Lower Pd loadings exhibited Pd-O(H)-In sites, while higher loadings resulted in Pd2In3 intermetallic compounds. These variations impacted catalytic performance, with Pd-O(H)-In catalysts showing heightened activity at lower temperatures due to the enhanced CO2 adsorption and H2 activation, and Pd2In3 catalysts performing better at elevated temperatures due to the further enhanced H2 activation. In situ DRIFTS studies revealed an alteration in key intermediates from *HCOO over In-O bonds to *COOH over Pd-O(H)-In and Pd2In3 sites, leading to a shift in the main reaction pathway transition and product distribution. Our findings underscore the importance of active site engineering for optimizing catalytic performance and offer valuable insights for the rational design of efficient CO2 conversion catalysts.

Silica supported Schiff-based palladium nanocatalyst for n-alkylation at room temperature

This works documents a new silica gel-supported nanocatalyst (Si@NSBPdNPs 3) with low Pd loadings for n-alkylation reactions at room temperature. Post synthesis characterisation using SEM-EDX and ICP techniques provided a quantitative assessment of palladium species. Additionally, TEM analysis unveiled an average palladium nanoparticle size of 5.87 ± 0.2 nm. In-depth X-ray Photoelectron Spectroscopy (XPS) analysis revealed its predominant composition as Pd(0) complexed to a Schiff base ligand on low cost silica matrix. The nanocatalyst exhibited high efficacy in the catalysis of n-alkylation (Michael addition) reactions with various α,β-unsaturated Michael acceptors, yielding the corresponding n-alkyl products at room temperature with exceptional yields. Notably, the catalyst exhibited good stability and could be easily separated from the reaction mixture. Moreover, the catalyst displayed recyclability potential, maintaining its original catalytic efficacy for up to seven cycles without any discernible loss.

Non-contrast magnetic resonance evaluation of active multiple sclerosis lesions: Emerging role of quantitative synthetic magnetic resonance imaging.

The current study aims to explore the utility of novel synthetic MRI-derived quantitative parameters including myelin-correlated volume (MyC) in identifying active MS lesions without injecting gadolinium contrast. 43 MS patients underwent institutional MS protocol including 3D FLAIR and post-contrast 3D T1VIBE sequence on a 1.5T MR Scanner in addition to synthetic MRI sequence. MS plaques were categorised into enhancing (C) and non-enhancing (N) lesions. They were also sub-categorised based on location into periventricular WM lesions (P), deep WM lesions (D), infratentorial lesions (I) and cortical-juxtacortical (C) lesions. ROIs were placed on Synthetic FLAIR images in MS lesions and quantitative parameters of R1, R2, PD and myelin-correlated volume (MyC) obtained. Sensitivity and specificity for various cut-off values to differentiate enhancing from non-enhancing multiple sclerosis lesions were calculated by performing ROC curve analysis and logistic regression analysis. Contrast enhancing lesions demonstrated significantly higher mean R1, R2 values and lower mean PD values in comparison to non-enhancing lesions (p < 0.05) but with limited specificity. Region-wise analysis revealed high AUC values for mean R1 and R2 at cortical-juxtacortical lesions (p < 0.001) followed by periventricular lesions (p < 0.003) for differentiating enhancing from non-enhancing lesions with no significant contribution from MyC and PD values. Synthetic MRI-derived quantitative parameters of mean R1, R2, MyC and PD hold value in differentiating contrast enhancing and non-enhancing MS lesions without administering gadolinium-based contrast agent. However, the current study did not achieve significant specificity for establishing the same.

Scalable Synthesis of ABBV-105 Enabled by Suzuki Coupling with Low Pd Loading, Ru-Catalyzed Asymmetric Hydrogenation, and Acylation Using Impinging Jet

Scalable Synthesis of ABBV-105 Enabled by Suzuki Coupling with Low Pd Loading, Ru-Catalyzed Asymmetric Hydrogenation, and Acylation Using Impinging Jet

Designing nanoporous Pd catalyst with dual enhancement of thermodynamics and kinetics for formic acid oxidation reaction

Conventional strategies for developing highly efficient electrocatalysts involve enhancing thermodynamics to minimize overpotential and improving kinetics to maximize reaction current. However, current research on Pd-based catalysts for formic acid oxidation reaction (FAOR) mainly focuses on accelerating its kinetics to increase the peak current. This study proposes a catalyst design that can simultaneously improve the kinetics and thermodynamics of FAOR. Specifically, the home-made catalyst (NPG-Pt1-Pd1) is obtained by sequentially depositing monolayer Pt and Pd shells on the surface of nanoporous gold (NPG) substrate. Compared with commercial Pd/C, this electrocatalyst exhibits a noticeable negative shift in onset potential (∼100 mV) and a significantly improved peak current (∼6 times). Experimental data and theoretical calculations demonstrate that NPG-Pt1-Pd1 exhibits a comparatively suitable adsorption energy for small molecules, not only reducing the overpotential but also accelerating the reaction rate of FAOR. Moreover, when applied in direct formic acid fuel cells (DFAFC), the NPG-Pt1-Pd1 anode with an exceptionally low Pd loading of 8.5 μg cm−2, achieves a remarkable power density of 141 mW cm−2. The power efficiency of Pd is 230 times that of Pd/C (1 mg cm−2, 73 mW cm−2). Therefore, this work provides a new methodology for developing efficient Pd-based FAOR electrocatalysts.

Utilizing an Integrated Flow Cathode-Membrane Filtration System for Effective and Continuous Electrochemical Hydrodechlorination.

Pd-based electrodes are recognized to facilitate effective electrochemical hydrodechlorination (EHDC) as a result of their superior capacity for atomic hydrogen (H*) generation. However, challenges such as electrode stability, feasibility of treating complex matrices, and high cost associated with electrode synthesis hinder the application of Pd-based electrodes for EHDC. In this work, we investigated the feasibility of degrading 2,4-dichlorophenol (2,4-DCP) by EHDC employing Pd-loaded activated carbon particles, prepared via a simple wet-impregnation method, as a flow cathode (FC) suspension. Compared to other Pd-based EHDC studies, a much lower Pd loading (0.02-0.08 mg cm-2) was used. Because of the excellent mass transfer in the FC system, almost 100% 2,4-DCP was hydrodechlorinated to phenol within 1 h. The FC system also showed excellent performance in treating complex water matrices (including hardness ion-containing wastewater and various other chlorinated organics such as 2,4-dichlorobenzoic acid and trichloroacetic acid) with a relatively low energy consumption (0.26-1.56 kW h m-3 mg-1 of 2,4-DCP compared to 0.32-7.61 kW h m-3 mg-1 of 2,4-DCP reported by other studies). The FC synthesized here was stable over 36 h of continuous operation, indicating its potential suitability for real-world applications. Employing experimental investigations and mathematical modeling, we further show that hydrodechlorination of 2,4-DCP occurs via interaction with H*, with no role of direct electron transfer and/or HO•-mediated processes in the removal of 2,4-DCP.

Hysteresis between gas breakdown and plasma discharge

In direct-current (DC) discharge, it is well known that hysteresis is observed between the Townsend (gas breakdown) and glow regimes. Forward and backward voltage sweep is performed using a one-dimensional particle-in-cell Monte Carlo collision (PIC-MCC) model considering a ballast resistor. When increasing the applied voltage after reaching the breakdown voltage (Vb), transition from Townsend to glow discharges is observed. When decreasing the applied voltage from the glow regime, the discharge voltage (Vd) between the anode–cathode gap can be smaller than the breakdown voltage, resulting in a hysteresis, which is consistent with experimental observations. Next, the PIC-MCC model is used to investigate the self-sustaining voltage (Vs) in the presence of finite initial plasma densities between the anode and cathode gap. It is observed that the self-sustaining voltage coincides with the discharge voltage obtained from the backward voltage sweep. In addition, the self-sustaining voltage decreases with increased initial plasma density and saturates above a certain initial plasma density, which indicates a change in plasma resistivity. The decrease in self-sustaining voltage is associated with the electron heat loss at the anode for the low pd (rarefied) regime. In the high pd (collisional) regime, the ion energy loss toward the cathode due to the cathode fall and the inelastic collision loss of electrons in the bulk discharge balance out. Finally, it is demonstrated that the self-sustaining voltage collapses to a singular value, despite the presence of a initial plasma, for microgaps when field emission is dominant, which is also consistent with experimental observations.

Managers, don't neglect your prospective employees to achieve your sustainability development goals

AbstractInstances of corporate social irresponsibility (CSI) in popular media, coupled with its negative consequences behooves a systematic assessment of the consequences of CSI. This study responds to calls for such research. Specifically, drawing on attribution theory, we investigate the role of CSI on prospective employees' employment intention (EI) and negative word‐of‐mouth (NWOM) propensity and the role of other condemning moral emotions (OCME) in mediating the relationship between CSI and EI and NWOM propensity. In addition, drawing on construal level theory, we investigate if psychological distance moderates the relationship between CSI and OCME, and thereby, impacts the mediation from CSI to EI and NWOM propensity through OCME. Results indicate that CSI decreases EI and enhances NWOM propensity, and these relationships are mediated via OCME. PD enhances the effect of CSI on EI and NWOM propensity through OCME such that lower PD is associated with a lower EI and higher NWOM propensity.

Theoretically predicted innovative palladium stripe dopingcobalt(1 1 1) surface with excellent catalytic performance for carbon monoxide oxidative coupling to dimethyl oxalate

Pd-based catalysts are extensively employed to catalyze CO oxidative coupling to generate DMO, while the expensive price and high usage of Pd hinder its massive application in industrial production. Designing Pd-based catalysts with high efficiency and low Pd usage as well as expounding the catalytic mechanisms are significant for the reaction. In this study, we theoretically predict that Pd stripe doping Co(1 1 1) surface exhibits excellent performance than pure Pd(1 1 1), Pd monolayer supporting on Co(1 1 1) and Pd single atom doping Co(1 1 1) surface, and clearly expound the catalytic mechanisms through the density functional theory (DFT) calculation and micro-reaction kinetic model analysis. It is obtained that the favorable reaction pathway is COOCH3–COOCH3 coupling pathway over these four catalysts, while the rate-controlling step is COOCH3+CO+OCH3→2COOCH3 on Pd stripe doping Co(1 1 1) surface, which is different from the case (2COOCH3→DMO) on pure Pd(1 1 1), Pd monolayer supporting on Co(1 1 1) and Pd single atom doping Co(1 1 1) surface. This study can contribute a certain reference value for developing Pd-based catalysts with high efficiency and low Pd usage for CO oxidative coupling to DMO.

Novel self‐doped Pd/Cu bimetals in CMC/PANI composites: Efficient heterogeneous catalyst for cooperative Sonogashira and Sonogashira‐cyclization tandem reactions

A new Pd/Cu bimetal catalyst supported on carboxymethylcellulose/polyaniline (CMC/PANI) composites (Pd/Cu@CMC/PANI) was fabricated to investigate the cooperative effect between Pd/Cu bimetals in Sonogashira reactions. This approach involves the self‐organization of aniline on CMC via H‐bond, enabling in situ oxidative polymerization using Pd(II) and Cu(II) ions as co‐oxidants. Subsequently, Pd and Cu are self‐deposited on the resulting CMC/PANI composites through the interaction of coordination and metathesis. The morphological and compositional analysis of the prepared catalyst was performed using various analytical tools such as ICP‐AES, FT‐IR, XPS, SEM, TEM, EDS, elemental mapping, and TGA. The Pd/Cu@CMC/PANI composite as a cooperative catalyst for the Sonogashira couplings exhibited high catalytic activity with relatively low Pd loading over its monometallic Pd counterpart, demonstrating the cooperative effect between Pd and Cu. Then, this bimetallic catalyst was successfully adapted for Sonogashira‐cyclization tandem reaction for the synthesis of benzofuran with excellent yields. Significantly, the Pd/Cu@CMC/PANI catalyst exhibited thermal stability under the reaction conditions and could be easily retrieved and reused repeatedly for five runs in the model reaction without significant discernible performance degradation.

Enhanced electroreduction of low-concentration nitrate using a Cu-Pd bimetallic cathode system: Performance evaluation, mechanism analysis, and potential applications

Copper (Cu) is a widely recognized cathode for the electrochemical reduction of nitrate (NO3-). Nevertheless, its practical applications are currently restricted due to limited activity and selectivity, particularly at low NO3- concentrations. Herein, a Cu-Pd bimetallic cathode system was designed for NO3- reduction reaction with low NO3- concentrations (≤40 mg-N L−1). In this system, a Cu nanowire array cathode was utilized for NO3- reduction, while a Pd/C particle cathode was employed for NO2- reduction with H2 generated in situ from a polypyrrole electrode. Due to the improved mass transfer and active sites derived from Pd/C particle cathode, along with the synergistic effects of NO3- reduction and NO2- reduction, the constructed Cu-Pd bimetallic cathode system achieved a 7.32-fold increase in NO3– removal rate and a 1.70-fold increase in NH4+ selectivity compared to the traditional Cu cathode. This performance surpassed that of many other state-of-the-art Cu-based cathodes under similar conditions. Moreover, the Cu-Pd bimetallic cathode system displayed high reusability, and extremely low Cu and Pd leaching. Additionally, it showed strong resistance to environmental factors and can adapt to a wide pH range (3−9) and various NO3- concentrations (10–40 mg-N L−1). The electron spin resonance and scavenger experiments confirmed that both direct electron transfer and indirect reduction by atomic H* were involved in the NO3- removal process, with indirect reduction playing a more significant role. Overall, our findings guide the design of superior catalytic systems for NO3- removal to enhance the activity and selectivity of NO3- reduction for efficient water purification.

Synthetic MRI and diffusion-weighted imaging for differentiating nasopharyngeal lymphoma from nasopharyngeal carcinoma: combination with morphological features.

To investigate the feasibility of synthetic MRI (syMRI), diffusion-weighted imaging (DWI), and their combination with morphological features for differentiating nasopharyngeal lymphoma (NPL) from nasopharyngeal carcinoma (NPC). Sixty-nine patients with nasopharyngeal tumours (NPL, n = 22; NPC, n = 47) who underwent syMRI and DWI were retrospectively enrolled between October 2020 and May 2022. syMRI and DWI quantitative parameters (T1, T2, PD, ADC) and morphological features were obtained. Diagnostic performance was assessed by independent sample t-test, chi-square test, logistic regression analysis, receiver operating characteristic curve (ROC), and DeLong test. NPL has significantly lower T2, PD, and ADC values compared to NPC (all P < .05), whereas no significant difference was found in T1 value between these two entities (P > .05). The morphological features of tumour type, skull-base involvement, Waldeyer ring involvement, and lymph nodes involvement region were significantly different between NPL and NPC (all P < .05). The syMRI (T2 + PD) model has better diagnostic efficacy, with AUC, sensitivity, specificity, and accuracy of 0.875, 77.27%, 89.36%, and 85.51%. Compared with syMRI model, syMRI + Morph (PD + Waldeyer ring involvement + lymph nodes involvement region), syMRI + DWI (T2 + PD + ADC), and syMRI + DWI + Morph (PD + ADC + skull-base involvement + Waldeyer ring involvement) models can further improve the diagnostic efficiency (all P < .05). Furthermore, syMRI + DWI + Morph model has excellent diagnostic performance, with AUC, sensitivity, specificity, and accuracy of 0.986, 95.47%, 97.87%, and 97.10%, respectively. syMRI and DWI quantitative parameters were helpful in discriminating NPL from NPC. syMRI + DWI + Morph model has the excellent diagnostic efficiency in differentiating these two entities. syMRI + DWI + morphological feature method can differentiate NPL from NPC with excellent diagnostic performance.

Influence of Abutments Surface (machined vs. laser-microgrooved) in Soft-tissue Response During One Year of Function: Clinical and Biochemical Outcomes of a RCT with Split-Mouth Design

The purpose of this study was to evaluate peri-implant soft tissue response by assessing IL-6, IL-1b and MMP-8 levels in peri-implant crevicular fluid (PICF) around machined vs. laser-microgrooved implants/healing/prosthetic abutments during 1 year of function. Twenty-four patients each received 2 one-stage implants in a split mouth design on the same jaw. In each patient, one implant, one immediate healing, and one prosthetic abutment with a machined surface (M group), and one implant, one immediate healing abutment and one prosthetic abutment with a laser-microgrooved surface (LMS group) were used. PICF sampling, pocket probing depths (PPD) and bleeding on probing (BOP) were assessed at 1, 3, and 12 months. IL-6, IL-1b and MMP-8 levels were determined by specific enzyme-linked immunosorbent assay systems (ELISA). Repeated measure ANOVA was used to run comparisons with groups and between groups months at 1, 3, and 12 months. At 3 and 12 months, the LMS group showed significantly lower PD, BOP and IL-6, IL-1β and MMP-8 levels than the M group (P&lt;.05). This study suggests the presence of more remodeling and/or inflammatory phenomena around implants/abutments with a machined surface than around implants/abutments with a laser-microgrooved surface.

Overcoming Pd Catalyst Deactivation in the C-H Coupling of Tryptophan Residues in Water Using Air as the Oxidant.

The Pd-catalyzed C-H activation of natural tryptophan residues has emerged as a promising approach for their direct synthetic modification. While using water as the solvent and harnessing air as the oxidant is enticing, these conditions induce catalyst deactivation by promoting the formation of inactive Pd(0) clusters. In this work, we have studied optimized Pd-based catalytic systems via nonsteady state kinetic analysis and in situ X-ray absorption spectroscopy (XAS) to overcome catalyst deactivation, which enables the effective use of lower Pd loadings.