Notas taxonómicas y biogeográficas sobre las esponjas del Estrecho de Magallanes

The sponge material from the Straits of Magellan collected by the research vessels Cariboo in 1991 and Victor Hensen in 1994, and by a shallow water diving team, were studied. Most of the investigated bottoms were soft or detritic and true rocky shores were seldom surveyed. However, alternative hard substrata are the holdfasts of dead laminarians, very abundant in the Straits, which represent a sort of microenvironment suitable for settling of sponges and other benthic organisms. Out of a total of more than 150 specimens, 44 demosponge species were identified. The resulting taxonomic pattern suggests a very heterogeneous sponge assemblage, partly related to the variety of the surveyed stations. Sponge communities are characterized by a patchy distribution, a high specific diversity and a low biomass. Most of the recorded species are of austral origin and distribution, confirming the Subantarctic character of the demosponge fauna of the Magellan Straits and its close affinity (14 species in common) with the fauna of the Antarctic continent. Twenty species identified in this study had never been recorded before from the Straits.El material objeto de este estudio se recogió durante las campañas del N/O “Cariboo” en 1991 y del “Victor Hensen” en 1994 en la zona del Estrecho de Magallanes. En el segundo periodo un grupo de buzos tomó muestras también en la zona litoral. La mayor parte de los muestreos se realizaron en fondos blandos y detríticos, los verdaderos fondos duros son raros. Estos fondos están remplazados por rizoides de laminarias muertas, muy abundantes en la zona del estrecho, que constituyen una especie de micro-ambiente, apto para la instalación de esponjas y otros organismos bentónicos. De un total de más de 150 ejemplares examinados se identificaron 44 especies de demospongias. El cuadro taxonómico sugiere una comunidad heterogénea de esponjas, debida, en parte, a la variedad de las estaciones muestreadas. La comunidad se caracteriza por una distribución agregada, por una diversidad específica elevada y por una biomasa reducida. La mayor parte de las especies encontradas son de origen y distribución austral. Se confirma asi el carácter sub-antártico de la fauna de demospongias del Estrecho de Magallanes y su estrecha afinidad (14 especies en común) con la fauna antártica continental. De las especies identificadas en este estudio 20 no habían sido, hasta ahora, encontradas en el Estrecho de Magallanes

Silica Meets Tannic Acid: Designing Green Nanoplatforms for Environment Preservation

Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO(2) NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solutions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-SiO(2) NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu(2+) ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO(2) NPs exhibited a different adsorption behaviour towards Cu(2+), which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu(2+) amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution

Effect of RE3+ on Structural Evolution of Rare-Earth Carbonates Synthesized by Facile Hydrothermal Treatment

In this work, nanoparticles of cerium hydroxycarbonates were synthesized by a facile hydrothermal treatment at 120°C with ammonium carbonate as the precipitating/mineralizer agent in diluted solution. The as-formed amorphous coprecipitate undergoes several morphological and structural modifications as a function of the duration of the hydrothermal treatment, leading after 8 h to the formation of monosized nanoparticles of hexagonal CeCO3OH. A similar behavior has been found when neodymium-based precursors are used as well, whereas the same treatment produces very different results by using different lanthanides-based precursors in terms of formed phases and morphologies, thus leading to the formation of pure tengerite-type structure phases, biphasic systems (tengerite type and hexagonal), or even entirely amorphous systems. Furthermore, the hydrothermal transformation is influenced by the redox behavior of the rare-earth cation (i.e., cerium) too, eventually resulting in the formation of fluorite-like structures. Therefore, a specific pathway of Ce(III) precursor transformations during hydrothermal treatment is proposed in this paper. Definitely, our results show that ammonium carbonate can be used as the precipitating/mineralizer agent to obtain cerium, doped-cerium, and neodymium hydroxycarbonates, which show excellent morphologies (i.e., characterized by spherical, nanosized particles with monomodal size distribution). Therefore, they can be used as optimal precursors for oxide powders. Conversely, when tengerite-type carbonate precursors are formed, their morphology is characterized by large and acicular particles

Effect of the Precipitating Agent on the Synthesis and Sintering Behavior of 20 mol %

Nanocrystalline 20 mol% samaria-doped ceria powders (Ce0.8Sm0.2O1.9) were synthesized by coprecipitation techniques using various precipitating agents in aqueous solution: ammonia, ammonium carbonate, tetramethylammonium hydroxide, and urea. The synthesized powders after calcination at 600°C possess a fluorite structure with nanometric size although they are characterized by a very different morphology and degree of agglomeration. Remarkable differences appear in the sintering behavior, especially because of the presence of hard agglomerates. The precipitating agent has therefore a crucial role in the coprecipitation process, which influences the morphology of the powders and in turn the sintering behavior. The obtained results clearly reveal that ammonium carbonate and urea are the best precipitating agents to obtain final dense products after sintering

CT-Guided Interventions Using a Free-Hand, Optical Tracking System: Initial Clinical Experience

Purpose: The present study was designed to evaluate the geometrical accuracy and clinical applicability of a new, free-hand, CT-guided, optical navigation system. Methods: Fifteen procedures in 14 consecutive patients were retrospectively analyzed. The navigation system was applied for interventional procedures on small target lesions, in cases with long needle paths, narrow access windows, or when an out-of-plane access was expected. Mean lesion volume was 27.9ml, and mean distance to target measured was 107.5mm. Eleven of 15 needle trajectories were planned as out-of-plane approaches regarding the axial CT plane. Results: Ninety-one percent of the biopsies were diagnostic. All therapeutic interventions were technically successful. Targeting precision was high with a mean distance of the needle tip from planned target of 1.98mm. Mean intervention time was 1:12h. A statistically significant correlation between angular needle deviation and intervention time (p=0.007), respiratory movement of the target (p=0.008), and body mass index (p=0.02) was detected. None of the evaluated parameters correlated significantly with the distance from the needle tip to the planned target. Conclusions: The application of a navigation system for complex CT-guided procedures provided safe and effective targeting within a reasonable intervention time in our serie

Stopping power of helium gas for ^9Be ions from 2 to 31 MeV

Abstract The stopping power of helium gas for 9Be ions from 2 to 31 MeV is experimentally determined using an indirect method. The residual energy of the 9Be beam as a function of the gas thickness is measured and the stopping power determined by differentiating the thickness–energy curve. The results are compared with predictions of the semi-empirical codes SRIM-2003 and MSTAR. Our data are in better agreement with the MSTAR calculations. The elastic scattering excitation function for the system 9Be + α, extracted using the thick target technique and our stopping power data, is in excellent agreement with the ones measured directly confirming the quality of our data

Simulated Moon Agglutinates Obtained from Zeolite Precursor by Means of a Low-Cost and Scalable Synthesis Method

A practical, inexpensive, and scalable synthesis method, based on the Fe2+ exchange of two commercial zeolites (i.e., Na-A and Na-X) followed by reductive thermal treatment at 1023 K, allowed obtaining nanocomposites where Fe0 nanoparticles are dispersed within an agglutinitic glassy matrix stemming from the amorphization of the zeolite precursor. The materials were characterized by means of atomic absorption spectrometry, X-ray powder diffraction followed by Rietveld analysis, transmission electron microscopy, N2 adsorption/desorption isotherms at 77 K, measurements of grain size distribution, magnetic properties measurements, broadband dielectric spectroscopy, and DC conductivity measurements. The physicochemical characterization showed that the final nanocomposites could be suitable as a new type of “simulated” Moon agglutinate, a component that is lacking in most of the current lunar regolith/soil simulants

Multi-organ impairment and long COVID: a 1-year prospective, longitudinal cohort study.

ObjectivesTo determine the prevalence of organ impairment in long COVID patients at 6 and 12 months after initial symptoms and to explore links to clinical presentation.DesignProspective cohort study.ParticipantsIndividuals.MethodsIn individuals recovered from acute COVID-19, we assessed symptoms, health status, and multi-organ tissue characterisation and function.SettingTwo non-acute healthcare settings (Oxford and London). Physiological and biochemical investigations were performed at baseline on all individuals, and those with organ impairment were reassessed.Main outcome measuresPrimary outcome was prevalence of single- and multi-organ impairment at 6 and 12 months post COVID-19.ResultsA total of 536 individuals (mean age 45 years, 73% female, 89% white, 32% healthcare workers, 13% acute COVID-19 hospitalisation) completed baseline assessment (median: 6 months post COVID-19); 331 (62%) with organ impairment or incidental findings had follow-up, with reduced symptom burden from baseline (median number of symptoms 10 and 3, at 6 and 12 months, respectively). Extreme breathlessness (38% and 30%), cognitive dysfunction (48% and 38%) and poor health-related quality of life (EQ-5D-5L ConclusionsOrgan impairment persisted in 59% of 331 individuals followed up at 1 year post COVID-19, with implications for symptoms, quality of life and longer-term health, signalling the need for prevention and integrated care of long COVID.Trial Registration: ClinicalTrials.gov Identifier: NCT04369807

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients