From electrospray ionization to cold-spray ionization: How to evaluate the cooling effect on the gaseous ions?

Two methods of survival yields (SY) measurement treatment of thermometer ions whose fragmentation is activated by in-source collision induced dissociation have been investigated for evaluating the mean internal () and thermal () energies of gaseous ions produced by electrospray ionization and cold-spray ionization (CSI). One of the methods is based on the use of the internal energy distributions (P (Eint )) as sigmoid derivatives connecting the experimental survival yields of different substituted benzylpyridinium cations. The values are therefore converted in a thermal-like parameter called vibrational temperature (Tvib ) then obtained at each value of the voltage of the desolvation area. The second method is based on the modelling of ion behavior by the MassKinetics software where the value of the characteristic temperature parameter (Tchar ) is used for fitting theoretical survival yields (SYtheo ) with experimental data (SYexp ) calculated at several activation energy. A linear correlation is evidenced between the values of internal or thermal energy and the voltage of the orifice 1 at the origin of the ion activation in the desolvation area. The extrapolation at zero voltage of the thermal-like parameters (Tvib and Tchar ) indicates that, in agreement with the literature data, the ions are relatively hot in ESI (~650 K). But the use of a CSI source lowers this temperature down to ~300 K. In addition, with cold-spray ionization, this cooling effect is more important when methanol is used instead of acetonitrile although these two solvents have no influence on the gaseous ion temperature in electrospray ionization.

Electrophilic and nucleophilic gas phase reactivity of the Janus cluster-based anions [{Mo6Cl8}Cl5□]- (□ = lacuna).

The lacunary monocharged anion [{Mo6Cli8}Cla5□a]- presents concomitantly a strongly electrophilic site and a nucleophilic one. This Janus character in terms of reactivity is confirmed by its gas phase reaction with [Br6Cs4K]- to form [{Mo6Cli8}Cla5Bra]2- and by its unusual self-reactivity leading to [{Mo6Cli8}Cla6]2- dianions.

MFI-11 Predicts Post-Operative Serious Complications in Patients Undergoing Surgery for Odontoid Fractures.

STUDY DESIGN: Retrospective Cohort. OBJECTIVES: The objective of this study was to analyze postoperative complications in different mFI-11 groups after surgery for odontoid fractures in a geriatric population. METHODS: A single center retrospective review of odontoid fractures surgery (between 2013 and 2022) in patients aged 65 years and older was conducted. The primary outcome was the occurrence of a major complication (Calvien-Dindo ≥4) within 30 days post-surgery. The secondary outcome was the occurrence of a major complication within 3 months after surgery, and death within 1-month post-surgery. Survival curve, multi-variate analysis was performed and adjusted receiver operating characteristic curves were generated. RESULTS: There were 92 patients included in this study, with a mean age of 80.5 years. Serious complication occurred for 16 patients (17%) during hospitalization. Multivariate analysis demonstrated an mFI 11 >.27 was strongly and independently associated with serious complications within 1-month post-surgery (OR = 16.7, 95% CI = 4.50-83), as well as serious complications within 3 months post-surgery (OR = 11.8, 95% CI = 3.48-49.1) and death within 1 month post-surgery (OR = 11.7; 95% CI = 3.02-60.4). The Receiver Operator Characteristics (ROC) curves for the three models all have an Area Under the Curve (AUC) value greater than 0.7. CONCLUSIONS: The mFI-11 is a straightforward and validated tool that can be used during the preoperative period to identify the patient's level of frailty and assess their risk of postoperative complications. Patients with mFI-11 ≥.27 are at greater risk of serious complications within 1 and 3 months' post-surgery and death within 1 month post-surgery.

Natural Course and Prognosis of Primary Spinal Glioblastoma: A Nationwide Study.

BACKGROUND AND OBJECTIVES: Primary spinal glioblastoma (PsGBM) is extremely rare. The dramatic neurologic deterioration and unresectability of PsGBM makes it a particularly disabling malignant neoplasm. Because it is a rare and heterogeneous disease, the assessment of prognostic factors remains limited. METHODS: PsGBMs were identified from the French Brain Tumor Database and the Club de Neuro-Oncologie of the Société Française de Neurochirurgie retrospectively. Inclusion criteria were age 18 years or older at diagnosis, spinal location, histopathologic diagnosis of newly glioblastoma according to the 2016 World Health Organization classification, and surgical management between 2004 and 2016. Diagnosis was confirmed by a centralized neuropathologic review. The primary outcome was overall survival (OS). Therapeutic interventions and neurologic outcomes were also collected. RESULTS: Thirty-three patients with a histopathologically confirmed PsGBM (median age 50.9 years) were included (27 centers). The median OS was 13.1 months (range 2.5-23.7), and the median progression-free survival was 5.9 months (range 1.6-10.2). In multivariable analyses using Cox model, Eastern Cooperative Oncology Group (ECOG) performance status at 0-1 was the only independent predictor of longer OS (hazard ratio [HR] 0.13, 95% CI 0.02-0.801; p = 0.02), whereas a Karnofsky performance status (KPS) score <60 (HR 2.89, 95% CI 1.05-7.92; p = 0.03) and a cervical anatomical location (HR 4.14, 95% CI 1.32-12.98; p = 0.01) were independent predictors of shorter OS. The ambulatory status (Frankel D-E) (HR 0.38, 95% CI 0.07-1.985; p = 0.250) was not an independent prognostic factor, while the concomitant standard radiochemotherapy with temozolomide (Stupp protocol) (HR 0.35, 95% CI 0.118-1.05; p = 0.06) was at the limit of significance. DISCUSSION: Preoperative ECOG performance status, KPS score, and the location are independent predictors of OS of PsGBMs in adults. Further analyses are required to capture the survival benefit of concomitant standard radiochemotherapy with temozolomide.

Development of new localized surface plasmon resonance interfaces based on gold nanostructures sandwiched between tin-doped indium oxide films.

This article reports on the fabrication and characterization of plasmonic interfaces composed of a sandwiched structure comprising a tin-doped indium oxide (ITO) substrate, gold nanostructures (Au NSs), and a thin ITO film overcoating. The change in the optical characteristics of the ITO/Au NSs/ITO interfaces as a function of the ITO overlayer thickness (d(ITO) = 0-200 nm) was followed by recording UV-vis transmission spectra. The influence of the thickness of the ITO overcoating on the position and shape of the plasmonic signal is discussed. The possibility to functionalize the ITO/Au NSs/ITO interfaces chemically is demonstrated by covalently linking ethynyl ferrocene to azide-terminated ITO/Au NSs/ITO interfaces. The resulting interfaces were characterized using X-ray photoelectron spectroscopy (XPS), electrochemical (cyclic voltammetry and differential pulse voltammetry) techniques, and UV-vis transmission spectroscopy.

Conservative versus Surgical Treatment for Odontoid Fracture: Is the Surgical Treatment Harmful? Systematic Review and Meta-Analysis.

BACKGROUND: Odontoid fracture is a common injury especially in elderly people. Despite some recent studies arguing in favor of surgery, the best treatment is still being debated. OBJECTIVE: We systematically review and analyze the comparative literature between surgical and conservative treatments of odontoid fractures. METHODS: We systematically searched Medline and the Cochrane Library for studies reported from January 1990 to May 2019 in English. Comparative studies evaluating the results of surgical and conservative treatments for odontoid fractures were eligible for inclusion. Combined relative risks (RRs) for mortality at last follow-up, union or nonunion rates, and complications were calculated. Methodological quality was assessed using the Newcastle-Ottawa Scale. Influence of age and year of publication on treatment effect was explored using a meta-regression analysis. RESULTS: A total of 1438 articles were identified, of which 30 articles with 2463 patients were eligible for inclusion. There was a trend toward lower mortality in the surgical group (RR, 0.80; 95% confidence interval [CI], 0.63-1.02). Nonunion rates (RR, 0.41; 95% CI, 0.28-0.6) were lower in the surgical group. Union rates were higher in the surgical group (RR, 1.26; 95% CI, 1.11-1.45). No significant influence of age or year of publication on treatment effect was found. CONCLUSIONS: Based on this meta-analysis of nonrandomized comparative studies, surgical treatment seems not to be inferior to conservative treatments. The conclusions of this study remain limited by the low quality of the evidence available. Randomized controlled studies are required.

Effect of Titanium Dioxide Film Thickness on Photocatalytic and Bactericidal Activities Against Listeria monocytogenes.

Structural, microstructural and bactericidal surface properties of TiO2 -coated glass substrates elaborated by reactive Radiofrequency sputtering are investigated. As pathogenic bacteria in biofilms are a major concern in food industries due to their growing resistance to cleaning and sanitizing procedures, the development of photoactive surfaces exhibiting bactericidal properties is acknowledged as an effective approach to tackle bacterial contaminations. Our principal aim concerns the study of the photoactive top-layer thickness impact (from 80 nm to ~500 nm) on Listeria monocytogenes. Structural characterization of the TiO2 layers demonstrates that anatase and rutile phases are both present, depending on the film thickness. Photocatalytic activity of the samples has been evaluated through the degradation of aqueous methylene blue (MB) solutions under UVA light illumination for various time periods. The results show an efficiency rating increase according to TiO2 film thickness up to a threshold value close to 400 nm. Moreover, a significant decrease of the adherent bacteria number is observed after 20 min of UVA illumination. The quantitative study of the bactericidal activity associated with scanning electron microscopy observations of the postprocess bacteria damaged cells demonstrates the efficiency of the 240-nm-thick TiO2 coating sample. The results are correlated with the production of hydroxyl radicals during the process of photocatalysis.

A Twofold Approach in Loss Reduction of KTa0.5Nb0.5O3 Ferroelectric Layers for Low-Loss Tunable Devices at Microwaves.

Ferroelectric oxide films are attractive to design and fabricate reconfigurable and miniaturized planar devices operating at microwaves due to the large electric field dependence of their dielectric permittivity. In particular, KTa1-xNbxO3 (KTN) ferroelectric material presents a high tunability under moderate dc bias electric field. However, its intrinsic dielectric loss strongly contributes to the global loss of the related devices and limits their application areas at microwaves. In this paper, a twofold approach is investigated to reduce the device loss. The intrinsic loss of KTN is first reduced by doping the ferroelectric material with a low-loss dielectric material, namely, MgO. Second, the doped ferroelectric films are confined using an original laser microetching process. Both routes have been implemented here to provide a synergic effect on the total insertion loss of the microwave test device, namely, a coplanar waveguide stub resonator. The experimental data demonstrate a decrease of the intrinsic loss by a factor of ~2 and a decrease of the global loss by a factor of ~4 with a frequency tunability close to 10% at ~10 GHz under a moderate biasing (80 kV/cm).

Dielectric Characteristics and Microwave Absorption of Graphene Composite Materials.

Nowadays, many types of materials are elaborated for microwave absorption applications. Carbon-based nanoparticles belong to these types of materials. Among these, graphene presents some distinctive features for electromagnetic radiation absorption and thus microwave isolation applications. In this paper, the dielectric characteristics and microwave absorption properties of epoxy resin loaded with graphene particles are presented from 2 GHz to 18 GHz. The influence of various parameters such as particle size (3 µm, 6-8 µm, and 15 µm) and weight ratio (from 5% to 25%) are presented, studied, and discussed. The sample loaded with the smallest graphene size (3 µm) and the highest weight ratio (25%) exhibits high loss tangent (tanδ = 0.36) and a middle dielectric constant ε' = 12-14 in the 8-10 GHz frequency range. As expected, this sample also provides the highest absorption level: from 5 dB/cm at 4 GHz to 16 dB/cm at 18 GHz.