A model for molecular adsorption on the surface of a columnar structure including steric effects and adsorbate–adsorbate repulsive interactions

Two-dimensional Monte Carlo simulations for adsorption on a columnar structured substrate were made to explore the steric effects of pore width and depth on molecular adsorption under adsorbate-adsorbate repulsive interactions. Simulation adsorption data fit a Frumkin-type isotherm for each set of pore width, depth and top column dimensions. As pore depth increases and pore width approaches the adsorbate molecular size, the surface coverage by adsorbed particles decreases sharply. Therefore, the adsorbate–adsorbate interaction parameters derived from the simulated isotherms exhibit a marked dependence on the substrate roughness factor (R). Phenomenologically, the influence of R on the isotherms is smoothed down by introducing a correction factor (f), which allowed us to collapse all simulated isotherms into a single isotherm. Results from the model are qualitatively compared to earlier observations about the influence of columnar structured gold surface roughness on the adsorption of 1,10-phenantroline in acid solution (oph) at constant potential (E > Epzc)Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Steric effects on molecular adsorption at columnar surfaces : A model for the adsorption of pyridine on gold electrodes

Results for pyridine (Py) adsorption on columnar-structured (cs) gold substrates from acid solutions at different potentials and 298 K are compared to the predictions of a recently proposed Langmuirian adsorption model at columnar surfaces. The difference in the apparent adsorption Gibbs energy derived from the adsorption isotherm of Py on cs- and smooth gold substrates was accounted for by a correction factor (f) that depends on the roughness (R) of the substrate according to f∝R−n, as expected from Monte Carlo simulation of the model. This agreement indicates that the substrate geometry plays a key role in the interpretation of adsorption isotherms.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Scanning Tunneling Microscopy and Scanning Electron Microscopy Observations of the Early Stage of Silver Deposition on Graphite Single Crystal Electrodes

The early stages of Ag overpotential deposition on highly oriented pyrolytic graphite (HOPG) from Ag+-ion-containing acid solutions have been studied by ex situ scanning tunneling microscopy and scanning electron microscopy imaging complemented with electrochemical, energy dispersive X-ray analysis, and Auger electron spectroscopy data. Nucleation and 3D Ag growth initiate at surface defects. Unstructured 3D Ag nuclei decorating HOPG steps and flat geometric Ag islands are formed around the steps. The island structure is compatible with a local layer-by-layer growth. The entire morphology of the Ag deposit is consistent with a growth mechanism involving Ag atom diffusion from 3D nuclei at step edges toward Ag flat domains. Images with atomic resolution reveal large uncovered HOPG areas and Ag submonolayer domains with the nearest-neighbor distance d = 0.33 ± 0.02 nm, whereas flat Ag islands exhibit d = 0.29 ± 0.02 nm as expected for the nearest-neighbor distance in the Ag lattice. A model for these structures is discussed.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

A model for molecular adsorption on the surface of a columnar structure including steric effects and adsorbate–adsorbate repulsive interactions

Two-dimensional Monte Carlo simulations for adsorption on a columnar structured substrate were made to explore the steric effects of pore width and depth on molecular adsorption under adsorbate-adsorbate repulsive interactions. Simulation adsorption data fit a Frumkin-type isotherm for each set of pore width, depth and top column dimensions. As pore depth increases and pore width approaches the adsorbate molecular size, the surface coverage by adsorbed particles decreases sharply. Therefore, the adsorbate–adsorbate interaction parameters derived from the simulated isotherms exhibit a marked dependence on the substrate roughness factor (R). Phenomenologically, the influence of R on the isotherms is smoothed down by introducing a correction factor (f), which allowed us to collapse all simulated isotherms into a single isotherm. Results from the model are qualitatively compared to earlier observations about the influence of columnar structured gold surface roughness on the adsorption of 1,10-phenantroline in acid solution (oph) at constant potential (E > Epzc)Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Steric effects on molecular adsorption at columnar surfaces : A model for the adsorption of pyridine on gold electrodes

Results for pyridine (Py) adsorption on columnar-structured (cs) gold substrates from acid solutions at different potentials and 298 K are compared to the predictions of a recently proposed Langmuirian adsorption model at columnar surfaces. The difference in the apparent adsorption Gibbs energy derived from the adsorption isotherm of Py on cs- and smooth gold substrates was accounted for by a correction factor (f) that depends on the roughness (R) of the substrate according to f∝R−n, as expected from Monte Carlo simulation of the model. This agreement indicates that the substrate geometry plays a key role in the interpretation of adsorption isotherms.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Staging Parkinson’s Disease Combining Motor and Nonmotor Symptoms Correlates with Disability and Quality of Life

Malaltia de Parkinson; Qualitat de vidaEnfermedad de Parkinson; Calidad de vidaParkinson's Disease; Quality of LifeIntroduction. In a degenerative disorder such as Parkinson’s disease (PD), it is important to establish clinical stages that allow to know the course of the disease. Our aim was to analyze whether a scale combining Hoehn and Yahr’s motor stage (H&Y) and the nonmotor symptoms burden (NMSB) (assessed by the nonmotor symptoms scale (NMSS)) provides information about the disability and the patient’s quality of life (QoL) with regard to a defined clinical stage. Materials and Methods. Cross-sectional study in which 603 PD patients from the COPPADIS cohort were classified according to H&Y (1, stage I; 2, stage II; 3, stage III; 4, stage IV/V) and NMSB (A: NMSS = 0–20; B: NMSS = 21–40; C: NMSS = 41–70; D: NMSS ≥ 71) in 16 stages (HY.NMSB, from 1A to 4D). QoL was assessed with the PDQ-39SI, PQ-10, and EUROHIS-QOL8 and disability with the Schwab&England ADL (Activities of Daily Living) scale. Results. A worse QoL and greater disability were observed at a higher stage of H&Y and NMSB (). Combining both (HY.NMSB), patients in stages 1C and 1D and 2C and 2D had significantly worse QoL and/or less autonomy for ADL than those in stages 2A and 2B and 3A and 3B, respectively (; e.g., PDQ-39SI in 1D [n = 15] vs 2A [n = 101]: 28.6 ± 17.1 vs 7.9 ± 5.8; ). Conclusion. The HY.NMSB scale is simple and reflects the degree of patient involvement more accurately than the H&Y. Patients with a lower H&Y stage may be more affected if they have a greater NMS burden

Scanning Tunneling Microscopy and Scanning Electron Microscopy Observations of the Early Stage of Silver Deposition on Graphite Single Crystal Electrodes

The early stages of Ag overpotential deposition on highly oriented pyrolytic graphite (HOPG) from Ag+-ion-containing acid solutions have been studied by ex situ scanning tunneling microscopy and scanning electron microscopy imaging complemented with electrochemical, energy dispersive X-ray analysis, and Auger electron spectroscopy data. Nucleation and 3D Ag growth initiate at surface defects. Unstructured 3D Ag nuclei decorating HOPG steps and flat geometric Ag islands are formed around the steps. The island structure is compatible with a local layer-by-layer growth. The entire morphology of the Ag deposit is consistent with a growth mechanism involving Ag atom diffusion from 3D nuclei at step edges toward Ag flat domains. Images with atomic resolution reveal large uncovered HOPG areas and Ag submonolayer domains with the nearest-neighbor distance d = 0.33 ± 0.02 nm, whereas flat Ag islands exhibit d = 0.29 ± 0.02 nm as expected for the nearest-neighbor distance in the Ag lattice. A model for these structures is discussed.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Long-term safety and effectiveness of levodopa-carbidopa intestinal gel infusion

Levodopa-carbidopa intestinal gel () infusion has demonstrated to improve motor fluctuations. The aim of this study is to assess the long-term safety and effectiveness of infusion in advanced Parkinson's disease () patients with motor fluctuations and its effect in nonmotor symptoms. Adverse events () and their management, clinical motor, and nonmotor aspects were assessed up to 10 years. Thirty-seven patients were treated with ; in three subsets of patients, specific batteries of tests were used to assess cognitive and behavior assessment for 6 months, quality of sleep for 6 months, and quality of life and caregiver burden for 1 year. There was a high number of , but manageable, most of mild and moderate severity. All patients experienced significant improvement in motor fluctuations with a reduction in mean daily off time of 4.87 hr after 3 months (n = 37) to 6.25 hr after 9 years (n = 2). Diskynesias remained stables in 28 patients (75.7%) and improved in 5 patients (13.5%). There was no neuropsychological deterioration, but an improvement in attentional functions, voluntary motor control, and semantic fluency. Quality of sleep did not worsen, and there was an improvement in the subjective parameters, although overnight polysomnography did not change. There was a significant sustained improvement of 37% in -Q39 after 3 months and to 1 year, and a significant reduction in caregiver burden of 10% after 3 months. infusion is a safe and efficacious treatment for the control of motor fluctuations, and for improvement or nonworsening of nonmotor aspects, long-term sustained, and feasible for use in routine care

Impaired proteasome activity and neurodegeneration with brain iron accumulation in FBXO7 defect

FBXO7 is implicated in the ubiquitin–proteasome system and parkin-mediated mitophagy. FBXO7defects cause a levodopa-responsive parkinsonian-pyramidal syndrome(PPS). Methods: We investigated the disease molecular bases in a child with PPS and brain iron accumulation. Results: A novel homozygous c.368C>G (p.S123*) FBXO7 mutation was identified in a child with spastic paraplegia, epilepsy, cerebellar degeneration, levodopa nonresponsive parkinsonism, and brain iron deposition. Patient’s fibroblasts assays demonstrated an absence of FBXO7 RNA expression leading to impaired proteasome degradation and accumulation of poly-ubiquitinated proteins. Conclusion: This novel FBXO7 phenotype associated with impaired proteasome activity overlaps with neurodegeneration with brain iron accumulation disorders.Fundacio La Marato de TV3 [Grants 20143130 to BPD, and 20143131 to CE], by the Instituto de Salud Carlos III (ISCIII) - Subdireccion General de Evaluacion y Fomento de la Investigacion within the framework of the National R + D+I Plan cofunded with ERDF funds [Grants PI18/01319 to BPD and PI18/00147 to CE], and by the Generalitat Valenciana [Grant PROMETEO/2018/ 135 to CE]. Part of the equipment employed in this work has been funded by Generalitat Valenciana and cofinanced with ERDF funds (OP ERDF of Comunitat Valenciana 2014-2020). SFR had a contract funded by the Spanish Foundation Per Amor a l’Art (FPAA). PS had a FPU-PhD fellowship funded by the Spanish Ministry of Education, Culture and Sport Inmunoterapia

Impaired proteasome activity and neurodegeneration with brain iron accumulation in FBXO7 defect

Altres ajuts: This work was funded by Instituto de Salud Carlos III; Ministerio de Educación, Cultura y Deporte; Spanish Foundation per Amor a l'Art (FPAA) grant ; Fundació la Marató de TV3 grants 20143130; and 20143131; Generalitat Valenciana grants OP ERDF of Comunitat Valenciana 2014-2020; and PROMETEO/2018/135.FBXO7 is implicated in the ubiquitin-proteasome system and parkin-mediated mitophagy. FBXO7defects cause a levodopa-responsive parkinsonian-pyramidal syndrome(PPS). Methods: We investigated the disease molecular bases in a child with PPS and brain iron accumulation. Results: A novel homozygous c.368C>G (p.S123*) FBXO7 mutation was identified in a child with spastic paraplegia, epilepsy, cerebellar degeneration, levodopa nonresponsive parkinsonism, and brain iron deposition. Patient's fibroblasts assays demonstrated an absence of FBXO7 RNA expression leading to impaired proteasome degradation and accumulation of poly-ubiquitinated proteins. Conclusion: This novel FBXO7 phenotype associated with impaired proteasome activity overlaps with neurodegeneration with brain iron accumulation disorders