Low pressure bottom-up synthesis of metal@oxide and oxide nanoparticles: control of structure and functional properties

Experimental activity on core@shell, metal@oxide, and oxide nanoparticles (NPs) grown with physical synthesis, and more specifically by low pressure gas aggregation sources (LPGAS) is reviewed, through a selection of examples encompassing some potential applications in nanotechnology. After an introduction to the applications of NPs, a brief description of the main characteristics of the growth process of clusters and NPs in LPGAS is given. Thereafter, some relevant case studies are reported: Formation of native oxide shells around the metal cores in core@shell NPs. Experimental efforts to obtain magnetic stabilization in magnetic core@shell NPs by controlling their structure and morphology. Recent advancements in NP source design and new techniques of co-deposition, with relevant results in the realization of NPs with a greater variety of functionalities. Recent results on reducible oxide NPs, with potentialities in nanocatalysis, energy storage, and other applications. Although this list is far from being exhaustive, the aim of the authors is to provide the reader a descriptive glimpse into the physics behind the growth and studies of low pressure gas-phase synthesized NPs, with their ever-growing potentialities for the rational design of new functional materials

Steering the magnetic properties of Ni/NiO/CoO core-shell nanoparticle films: The role of core-shell interface versus interparticle interactions

Supported core-shell Ni/NiO/CoO nanoparticle (NP) films were obtained by deposition of preformed and mass-selected Ni NPs on a buffer layer of CoO, followed by a top CoO layer. The resulting NPs have core/shell morphology, with a McKay icosahedral Ni core and a partially crystalline CoO shell. X-ray photoelectron spectroscopy evidenced the presence of a thin NiO layer, which was shown to be between the Ni core and the CoO shell by elemental TEM mapping. CoO and NiO shells with different thickness values were obtained, allowing us to investigate the evolution of the magnetic properties of the NP assemblies as a function of the oxide shell thickness. Both exchange-coupling and magnetostatic interactions significantly contribute to the magnetic behavior of Ni/NiO/CoO NP films. After the Ni/NiO/CoO NPs are cooled in a weak magnetic field, they have blocking temperature higher than room temperature because of strong magnetostatic interactions, which support the formation of a spin-glass-like state below similar to 250 K. Exchange coupling dominates the magnetic behavior after the NPs are cooled in a strong magnetic field. The exchange bias (EB) is in the 0.17-2.35 kOe range and strongly depends on the CoO thickness (0.4-2.7 nm), showing the onset of the EB at the few-nanometer scale. The switching field distribution showed that the EB opposes the magnetization reversal from the direction along the cooling field but it does not significantly ease the opposite process. The EB depends on t(CoO) only for t(NiO) <= 0.5 nm, but when NiO is 0.7 nm thick it strongly interacts with CoO and a large increase of the EB and coercivity is observed

Morphology and Optical Properties of Gas-Phase-Synthesized Plasmonic Nanoparticles: Cu and Cu/MgO

In this paper, an investigation of the properties of Cu and Cu/MgO nanoparticles (NPs) is presented. The NPs were obtained with gas-phase synthesis, and the MgO shells or matrices were formed via the co-deposition method on inert substrates. SEM and AFM were used to investigate the NP morphology on Si/SiOx, quartz, and HOPG. The Cu NPs revealed flattening of their shape, and when they were deposited on HOPG, diffusion and formation of small chains were observed. The embedding of Cu NPs in MgO was confirmed by TEM and EDX maps. XPS showed that Cu was in its metallic state, regardless of the presence of the surrounding MgO. UV–Vis revealed the presence of an intense localized surface plasmon resonance (LSPR) for Cu/MgO and for “bare” NPs. These results confirmed the role of MgO as a protective transparent medium for Cu, and the wavelength position of the LSPR in the Cu/MgO system was consistent with calculations. The wavelength position of the LSPR observed for “bare” and post-oxidized Cu NPs was probably affected by the formation of copper oxide shells after exposure to air. This study paves the way for the use of Cu/MgO NPs as plasmonic nanomaterials in applications such as photovoltaics and sensor technology

Arterial stiffness, sugar-sweetened beverages and fruits intake in a rural population sample: Data from the brisighella heart study

Introduction: There is conflicting information linking fruit and fructose intake with cardio metabolic disorders. The main objective of our study was to evaluate the association between intake of fruits and sugar-sweetened beverages, and carotid-femoral pulse wave velocity (cfPWV), a non-invasive marker of arterial aging, in a large population sample. Methods: For this study, we selected four age and sex-matched subgroups from the last Brisighella Heart Study population survey, after exclusion of those in secondary prevention for cardiovascular diseases, affected by gout and moderate-to-severe chronic kidney disease (defined as eGFR &lt; 60 mL/min), and/or actively treated with direct vasodilating drugs (calcium-antagonists, alpha-blockers, nitrates). The remaining subjects were classified into four groups: (1) low fruit and low sugar-sweetened beverage intake (LFLB), (2) high fruit and low sugar-sweetened beverage intake (HFLB), (3) low fruit and high sugar-sweetened beverage intake (LFHB), (4) high fruit and high sugar-sweetened beverage intake (HFHB). Results: CfPWV was significantly elevated in subjects consuming a higher fructose load, particularly when it was derived from industrially sweetened beverages (pooled LFHB &amp; HFHB: 9.6 ± 2.3 m/s; pooled LFLB &amp; HFLB: 8.6 ± 2.3 m/s, p &lt; 0.001). Moreover, the main predictors of cfPWV values were serum uric acid (B = 0.391, 95%CI 0.321–0.486, p = 0.001), fructose load from both fruits and sugar-sweetened beverages (B = 0.310, 95%CI 0.099–0.522, p = 0.004), triglycerides (B = 0.228, 95%CI 0.117–0.389, p = 0.018), fasting plasma glucose (B = 0.015, 95%CI 0.008–0.022, p &lt; 0.001) and estimated Glomerular Filtration Rate (B = −0.043, 95%CI −0.052–−0.035, p &lt; 0.001). Conclusion: our data suggest that increased intake of fructose derived from industrial sweetened beverages, though not from fruits, is associated with higher pulse wave velocity

Structure and Morphology of Silver Nanoparticles on the (111) Surface of Cerium Oxide

The structure of Ag nanoparticles of different size, supported on the cerium oxide (111) surface, was investigated by X-ray absorption fine structure at the Ag K-edge. The results of the data analysis in the near and extended energy range are interpreted with the help of the results obtained by X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements and allow to obtain a detailed atomic scale description of the model system investigated. The Ag nanoparticles have an average size of a few tens of angstroms, which increases with increasing deposited Ag amount. The nanoparticles show a slight tendency to nucleate at the step edges between different cerium oxide layers and they have a face centered cubic structure with an Ag-Ag interatomic distance contracted by 3-4% with respect to the bulk value. The interatomic distance contraction is mainly ascribed to dimensionality induced effects, while epitaxial effects have a minor role. The presence of Ag-O bonds at the interface between the nanoparticles and the supporting oxide is also detected. The Ag-O interatomic distance decreases with decreasing nanoparticle size

Twelve Variants Polygenic Score for Low-Density Lipoprotein Cholesterol Distribution in a Large Cohort of Patients With Clinically Diagnosed Familial Hypercholesterolemia With or Without Causative Mutations

: Background A significant proportion of individuals clinically diagnosed with familial hypercholesterolemia (FH), but without any disease-causing mutation, are likely to have polygenic hypercholesterolemia. We evaluated the distribution of a polygenic risk score, consisting of 12 low-density lipoprotein cholesterol (LDL-C)-raising variants (polygenic LDL-C risk score), in subjects with a clinical diagnosis of FH. Methods and Results Within the Lipid Transport Disorders Italian Genetic Network (LIPIGEN) study, 875 patients who were FH-mutation positive (women, 54.75%; mean age, 42.47±15.00 years) and 644 patients who were FH-mutation negative (women, 54.21%; mean age, 49.73±13.54 years) were evaluated. Patients who were FH-mutation negative had lower mean levels of pretreatment LDL-C than patients who were FH-mutation positive (217.14±55.49 versus 270.52±68.59 mg/dL, P<0.0001). The mean value (±SD) of the polygenic LDL-C risk score was 1.00 (±0.18) in patients who were FH-mutation negative and 0.94 (±0.20) in patients who were FH-mutation positive (P<0.0001). In the receiver operating characteristic analysis, the area under the curve for recognizing subjects characterized by polygenic hypercholesterolemia was 0.59 (95% CI, 0.56-0.62), with sensitivity and specificity being 78% and 36%, respectively, at 0.905 as a cutoff value. Higher mean polygenic LDL-C risk score levels were observed among patients who were FH-mutation negative having pretreatment LDL-C levels in the range of 150 to 350 mg/dL (150-249 mg/dL: 1.01 versus 0.91, P<0.0001; 250-349 mg/dL: 1.02 versus 0.95, P=0.0001). A positive correlation between polygenic LDL-C risk score and pretreatment LDL-C levels was observed among patients with FH independently of the presence of causative mutations. Conclusions This analysis confirms the role of polymorphisms in modulating LDL-C levels, even in patients with genetically confirmed FH. More data are needed to support the use of the polygenic score in routine clinical practice

Low pressure bottom-up synthesis of metal@oxide and oxide nanoparticles: control of structure and functional properties

Experimental activity on core@shell, metal@oxide, and oxide nanoparticles (NPs) grown with physical synthesis, and more specifically by low pressure gas aggregation sources (LPGAS) is reviewed, through a selection of examples encompassing some potential applications in nanotechnology. After an introduction to the applications of NPs, a brief description of the main characteristics of the growth process of clusters and NPs in LPGAS is given. Thereafter, some relevant case studies are reported: Formation of native oxide shells around the metal cores in core@shell NPs. Experimental efforts to obtain magnetic stabilization in magnetic core@shell NPs by controlling their structure and morphology. Recent advancements in NP source design and new techniques of co-deposition, with relevant results in the realization of NPs with a greater variety of functionalities. Recent results on reducible oxide NPs, with potentialities in nanocatalysis, energy storage, and other applications. Although this list is far from being exhaustive, the aim of the authors is to provide the reader a descriptive glimpse into the physics behind the growth and studies of low pressure gas-phase synthesized NPs, with their ever-growing potentialities for the rational design of new functional materials

A Randomized, Double-Blinded, Placebo-Controlled, Clinical Study of the Effects of a Nutraceutical Combination (LEVELIP DUO®) on LDL Cholesterol Levels and Lipid Pattern in Subjects with Sub-Optimal Blood Cholesterol Levels (NATCOL Study)

Phytosterols and red yeast rice are largely studied cholesterol-lowering nutraceuticals, respectively inhibiting the bowel absorption and liver synthesis of cholesterol. Our aim was to test the effect of combined nutraceutical-containing phytosterols and red yeast rice vs. a placebo on the lipid profile. We performed a parallel arms, double-blind, placebo-controlled clinical trial, randomizing 88 moderately hypercholesterolemic subjects to treatment with a combined nutraceutical containing phytosterols (800 mg) and red yeast rice, standardized to contain 5 mg of monacolins from Monascus purpureus, with added niacin (27 mg) and policosanols (10 mg) (LEVELIP DUO&reg;), or placebo. The mean LDL-Cholesterol (LDL-C) change at Week 8 was &minus;32.5 &plusmn; 30.2 mg/dL (&minus;19.8%) in the combined nutraceutical group and 2.5 &plusmn; 19.4 mg/dL (2.3%) in the placebo group. The estimated between-group difference of &minus;39.2 mg/dL (95% CI: &minus;48.6; &minus;29.8) indicates a statistically significant difference between treatments in favor of the combined nutraceutical (p &lt; 0.0001). Total Cholesterol (TC), non-HDL cholesterol (non-HDL-C), Apolipoprotein B, TC/HDL-C and LDL-C/HDL-C improved in a similar way in the combined nutraceutical group only. No significant changes in other clinical and laboratory parameters were observed. In conclusion, the tested combined nutraceutical was well tolerated, while significantly reducing the plasma levels of LDL-C, TC, non-HDL-C, ApoB, TC/HDL-C and LDL-C/HDL-C ratios in mildly hypercholesterolemic patients. Trial registration (ClinicalTrials.gov): NCT03739242