Distance of the alveolar antral artery from the alveolar crest. Related factors and surgical considerations in sinus floor elevation

In a variable proportion of maxillary sinuses alveolar antral artery is located close to the residual ridge, increasing the chances for haemorrhagic complications during sinus floor elevation procedures. Retrospective observational study of CBCT explorations performed for implant-treatment planning. The upper first molar area was selected for this study. The relative uncertainty (standard deviation of the measurement divided by its mean and expressed as a percentage from 0% to 100%) was chosen for determining the observational errors. For modeling the chances of AAA detection, the generalized additive models (GAM) approach was chosen. A total of 240 maxillary sinuses were studied (46.25% males) whose median median age was 58 years old (IQR: 52-66). Univariate models showed that the chances for an AAA-alvelar crest distance ?15mm increase in wider sinuses with lower, subsinusally edentulous crests. When distance is considered as a continuous variable, the best mutivariate model showed an explained deviance of 67% and included AAA diameter, distance AAA-sinus floor, sinus width, and shape, height and width of the residual ridge. Thinner AAAs are found closer to the crest (within the ?15mm safe distance). Bearing in mind the inclusion criteria and the limitations of this investigation, it is concluded that there is a high proportion of maxillary sinuses where AAA describes a course close to the alveolar crest (?15mm), which was classically considered a safe distance for SFE. This position is related to the presence of atrophic crests (depressed ridge form) and wide maxillary sinuses where the distance of the vessel to the floor of the sinus is small. This information may permit a better surgical planning of SFE procedures

Graphene etching on SiC grains as a path to interstellar polycyclic aromatic hydrocarbons formation.

Polycyclic aromatic hydrocarbons as well as other organic molecules appear among the most abundant observed species in interstellar space and are key molecules to understanding the prebiotic roots of life. However, their existence and abundance in space remain a puzzle. Here we present a new top-down route to form polycyclic aromatic hydrocarbons in large quantities in space. We show that aromatic species can be efficiently formed on the graphitized surface of the abundant silicon carbide stardust on exposure to atomic hydrogen under pressure and temperature conditions analogous to those of the interstellar medium. To this aim, we mimic the circumstellar environment using ultra-high vacuum chambers and investigate the SiC surface by in situ advanced characterization techniques combined with first-principles molecular dynamics calculations. These results suggest that top-down routes are crucial to astrochemistry to explain the abundance of organic species and to uncover the origin of unidentified infrared emission features from advanced observations. © 2014 Macmillan Publishers Limited. All rights reserved

Tumoral and normal brain tissue extraction protocol for wide-scope screening of organic pollutants

Little is known about the presence of organic pollutants in human brain (and even less in brain tumors). In this regard, it is necessary to develop new analytical protocols capable of identify-ing a wide range of exogenous chemicals in this type of samples (by combining target, suspect and non-target strategies). These methodologies should be robust and simple. This is particularly challenging for solid samples, as reliable extraction and clean-up techniques should be combined to obtain an optimal result. Hence, the present study focuses on the development of an analytical methodology that allows the screening of a wide range of organic chemicals in brain and brain tumor samples. This protocol was based on a solid-liquid extraction based on bead beating, solid-phase extraction clean-up with multi-layer mixed-mode cartridges, reconstitution and LC -HRMS analysis. To evaluate the performance of the extraction methodology, a set of 66 chemicals (e.g., pharmaceuticals, biocides, or plasticizers, among others) with a wide range of physicochemical properties was employed. Quality control parameters (i.e., linear range, sensitivity, matrix effect (ME%), and recoveries (R%)) were calculated and satisfactory results were obtained for them (e.g., R% within 60-120% for 32 chemicals, or ME% higher than 50% (signal suppression) for 79% of the chemicals)

Ciguatoxin Detection in Flesh and Liver of Relevant Fish Species from the Canary Islands

The Canary Islands are a ciguatoxin (CTX) hotspot with an established official monitoring for the detection of CTX in fish flesh from the authorised points of first sale. Fish caught by recreational fishermen are not officially tested and the consumption of toxic viscera or flesh could lead to ciguatera poisoning (CP). The objectives of this study were to determine the presence of CTX-like toxicity in relevant species from this archipelago, compare CTX levels in liver and flesh and examine possible factors involved in their toxicity. Sixty amberjack (Seriola spp.), 27 dusky grouper (Epinephelus marginatus), 11 black moray eels (Muraena helena) and 11 common two-banded seabream (Diplodus vulgaris) were analysed by cell-based assay (CBA) and Caribbean ciguatoxin-1 (C-CTX1) was detected by liquid chromatography mass spectrometry (LC-MS/MS) in all these species. Most of the liver displayed higher CTX levels than flesh and even individuals without detectable CTX in flesh exhibited hepatic toxicity. Black moray eels stand out for the large difference between CTX concentration in both tissues. None of the specimens with non-toxic liver showed toxicity in flesh. This is the first evidence of the presence of C-CTX1 in the common two-banded seabream and the first report of toxicity comparison between liver and muscle from relevant fish species captured in the Canary Islands.info:eu-repo/semantics/publishedVersio

Antioxidant and neuroprotective actions of IGF-II against glucocorticoid-induced toxicity in dopaminergic neurons.

The neurodegenerative Parkinson’s disease (PD) affects 1–3% of the population aged over 65. A wide range of pathways and mechanisms are involved in its pathogenesis, such as oxidative stress, mitochondrial dysfunction, inflammation and neuronal glucocorticoid-induced toxicity, which ultimately produce a progressive loss of nigral dopamine neurons. Insulin-like growth factor II (IGF-II) has shown antioxidant and neuroprotective effects in some neurodegenerative disorders. Therefore, our aim was to study IGF-II protective effects against oxidative damage on a cellular combined model of PD and mild to moderate stress, based on corticosterone (CORT), an endocrine response marker to stress, and the dopaminergic neurotoxin 1-methyl-4-phenylpyridinium (MPP+). The dopaminergic neuronal cell line SN4741 (RRID:CVCL_S466) derived from mouse substantia nigra were exposed to 200 μM MPP+, 0.5 μM CORT or both, with or without 25 ng/mL IGF-II, for 2.5 or 6 h. Cell viability, oxidative stress parameters, mitochondrial and dopamine markers and intracellular signaling pathways were evaluated. The administration of MPP+ or CORT individually led to cell damage compared to control situations, whereas the combination of both drugs produced very considerable toxic synergistic effect. IGF-II counteracts the mitochondrial-oxidative damage, protecting dopaminergic neurons from death and neurodegeneration. IGF-II maintained the tyrosine hydroxylase expression and promotes nuclear factor (erythroid-derived 2)-like 2 antioxidant response in a glucocorticoid receptor-dependent pathway, preventing oxidative cell damage and maintaining mitochondrial function. This work revealed the potential neuroprotective role of IGF-II to protect nigral dopamine neurons against mitochondrial-oxidative damage induced by CORT and MPP+ was demonstrated. Thus, IGF-II is a potential therapeutic tool for prevention and treatment of PD patients suffering mild to moderate emotional stress.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Atmospheric pressure gas chromatography-time-of-flight-mass spectrometry (APGC-ToF-MS) for the determination of regulated and emerging contaminants in aqueous samples after stir bar sorptive extraction (SBSE)

This work presents the development, optimization and validation of a multi-residue method for the simultaneous determination of 102 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and several types of pesticides in aqueous matrices. Water samples were processed using stir bar sorptive extraction (SBSE) after the optimization of several parameters: agitation time, ionic strength, presence of organic modifiers, pH, and volume of the derivatizing agent. Target compounds were extracted from the bars by liquid desorption (LD). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to time-of-flight (ToF-MS) mass spectrometry. A new ionization source, atmospheric pressure gas chromatography (APGC), was tested. The optimized protocol showed acceptable recovery percentages (50–100%) and limits of detection below 1 ng L−1 for most of the compounds. Occurrence of 21 out of 102 analytes was confirmed in several environmental aquatic matrices, including seawater, sewage effluent, river water and groundwater. Non-target compounds such as organophosphorus flame retardants were also identified in real samples by accurate mass measurement of their molecular ions using GC-APGC–ToF-MS. To the best of our knowledge, this is the first time that this technique has been applied for the analysis of contaminants in aquatic systems. By employing lower energy than the more widely used electron impact ionization (EI), AGPC provides significant advantages over EI for those substances very susceptible to high fragmentation (e.g., fragrances, pyrethroids)

IGF-II treatment prevents the oxidative damage derived by MPP+/MPTP administration in a cellular and animal model of Parkinson’s disease.

El factor de crecimiento de la insulina-II (IGF-II) ha mostrado efectos antioxidantes y neuroprotectores en algunos trastornos neurodegenerativos, como es la Enfermedad de Parkinson (EP). Analizamos el efecto de IGF-II y la implicación de la esfingosina kinasa (SPHK), en la citoarquitectura/función mitocondrial tras provocar daño oxidativo con la administración de la neurotoxina MPTP y su metabolito activo. La línea celular SN4741 se trató con MPP+ solo/en presencia de IGF-II (2 h). Los tratamientos fueron reemplazados por medio/IGF-II (2h), respectivamente. Se estudió: morfología (microscopía electrónica, EM), tasa de consumo de oxígeno (OCR) y muerte celular (LDH). MPTP/probenecid(p) por vía parenteral (35d) indujo un daño progresivo en la vía nigroestriatal dopaminérgica (DA-NSP) de los animales. En los días 36-44, se inyectó vehículo. El grupo control recibió vehículo siguiendo el mismo régimen de administración (1-44d). Otro grupo se trató con IGF-II una vez inducido el daño por MPTP (22-44 días). Para investigar el papel de IGF-II en la alteración conductual inducida por MPTP/p, se evaluó el rendimiento motor. Se realizó inmunotinción para marcadores dopaminérgicos y astrogliosis. Las células tratadas con MPP+ mostraron menos mitocondrias (EM) y con pérdida parcial/total de crestas, alteraciones de membrana y forma hinchada. IGF-II mantuvo el número de mitocondrias con morfología similar al control. La disminución de OCR tras la administración de MPP+ (30%) se recuperó con IGF-II. SPHK está implicada en este mecanismo, como indica su inhibición (MPP++IGF-II+MPA-08 6 veces > LDH vs MPP++IGF-II). En animales, IGF-II recuperó el efecto de MPTP sobre los marcadores DA-NSP y sobre el rendimiento motor. IGF-II contrarresta el aumento del estrés oxidativo y la disfunción mitocondrial inducida por la neurotoxina, el deterioro conductual y la degeneración de DA-NSP. SPHK estaría involucrada en este mecanismo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Few-layer antimonene electrical properties

Antimonene -a single layer of antimony atoms- and its few layer forms are among the latest additions to the 2D mono-elemental materials family. Numerous predictions and experimental evidence of its remarkable properties including (opto)electronic, energetic or biomedical, among others, together with its robustness under ambient conditions, have attracted the attention of the scientific community. However, experimental evidence of its electrical properties is still lacking. Here, we characterized the electronic properties of mechanically exfoliated flakes of few-layer (FL) antimonene of different thicknesses (∼ 2–40 nm) through photoemission electron microscopy, kelvin probe force microscopy and transport measurements, which allows us to estimate a sheet resistance of ∼ 1200 Ω sq−1 and a mobility of ∼ 150 cm2V−1s−1 in ambient conditions, independent of the flake thickness. Alternatively, our theoretical calculations indicate that topologically protected surface states (TPSS) should play a key role in the electronic properties of FL antimonene, which supports our experimental findings. We anticipate our work will trigger further experimental studies on TPSS in FL antimonene thanks to its simple structure and significant stability in ambient environmentsWe acknowledge financial support through the “Maríade Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-M), the Spanish MINECO through projects PCI2018-093081, FIS2016-80434-P, PID2019-109539GB-C43, PID2019- 106268GB-C31 and -C32, MAT2016-77608-C3-1-P and -3-P, MAT2013-46753-C2-2-P and MAT2017-85089-C2-1R, the EU Graphene Flagship funding (Graphene Flagship Core3 881603 and JTC2017/2D-Sb&Ge), the EU via the ERC-Synergy Program (GrantERC-2013-SYG-610256 NANOCOSMOS), the Comunidad Autónoma de Madrid through MAD2D-CM, S2018/NMT-4321 (NanomagCOST-CM) and the European StructuralFunds via FotoArt CM project (S2018/NMT-4367), and the Fundación Ramón Areces. S.P. acknowledges financial support by the VILLUM FONDEN via the Centre of Excellence for Dirac Materials (Grant No. 11744

Insights into Structure-Activity Relationships of Somatostatin Analogs Containing Mesitylalanine.

The non-natural amino acid mesitylalanine (2,4,6-trimethyl-L-phenylalanine; Msa) has an electron-richer and a more conformationally restricted side-chain than that of its natural phenylalanine counterpart. Taking these properties into account, we have synthesized ten somatostatin analogs containing Msa residues in different key positions to modify the intrinsic conformational flexibility of the natural hormone. We have measured the binding affinity of these analogs and correlated it with the main conformations they populate in solution. NMR and computational analysis revealed that analogs containing one Msa residue were conformationally more restricted than somatostatin under similar experimental conditions. Furthermore, we were able to characterize the presence of a hairpin at the pharmacophore region and a non-covalent interaction between aromatic residues 6 and 11. In all cases, the inclusion of a D-Trp in the eighth position further stabilized the main conformation. Some of these peptides bound selectively to one or two somatostatin receptors with similar or even higher affinity than the natural hormone. However, we also found that multiple incorporations of Msa residues increased the life span of the peptides in serum but with a loss of conformational rigidity and binding affinity