Sulfide weathering processes mediated by microfungi

This study aimed to experimentally investigate the interactions, the bioalteration, and the biocorrosion of sulfides mediated by three microfungi (Trichoderma harzianum group, Penicillium glandicola, P. brevicompactum) isolated within the open-air waste-rock dumps from Libiola mine (Liguria, Italy). Unaltered samples of pyrite-mineralizations from the same waste-rock dumps were ground and sieved into size fraction of 150-63 \u3bc m which resulted composed by single crystals of pyrite (>80 wt%), with minor quartz and trace amount of chalcopyrite. The mineral bioalteration tests were carried out for six weeks using Czapek-Dox agar medium (CZA). In each plate, four pyrite crystals or crystal fragments were set into the solid medium. After one week, pyrite grains were almost completely covered by mycelia of the three different fungi. The samples were examined, before and after the experimental procedure, using plane-polarized optical microscopy (transmitted- and reflected-light) and environmental scanning electron microscopy (ESEM-EDS). The ESEM analyses were performed in low-vacuum mode for the micromorphological analyses to characterize the evolution of the mineralfungi interactions during the different experimental steps. After six weeks covered by mycelia, the pyrite grains were collected and analyzed revealing that the surface of pyrite crystals was strongly corroded in all experimental tests. ESEM images underlined how pyrite alteration was strictlty associated with biological patterns (curves, rounded cracks, and sinuous traces). Corrosion patterns and etching pits were not related to specific crystallographic planes or weakness, but were randomly distributed on the crystal surfaces, in particular in correspondence of the fungal hyphae attachment. Moreover, in the same temporal interval, the control experiment performed in abiotic conditions did not show any dissolution evidences thus suggesting that in absence of fungal interactions the pyrite weathering did not occur or was much slower. The experimental results evidenced the active role of fungi in the pyrite crystal weathering and suggested that sulfide alteration was not only the consequence of the interactions between metabolites secreted by fungi and minerals, but there was also a possible bio-mechanical role of hyphae in corrosion through penetration, boring, and burrowing along weak crystal planes or microfractures. Finally, the evidences of biocorrosion led to evaluate the important role of fungi in the iron and sulfur cycles in sulfide-bearing materials, since fungal alteration systematically triggers sulfide to sulfate oxidation, causing local gypsum and Fe-oxyhydroxides precipitation within mycelium structure

Clinical predictive factors of pathologic complete response in locally advanced rectal cancer

Background: Predictive factors of pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) are still not identified. The purpose of this study was to define them. Materials and Methods: Data from consecutive LARC patients treated between January 2008 and June 2014 at our Institution were included in the analysis. All patients were treated with a long course of nCRT. Demographics, initial diagnosis and tumor extension details, as well as treatment modalities characteristics were included in the univariate and logistic regression analysis. Results: In total 99 patients received nCRT, of whom 23 patients (23.2%) achieved pCR. Patients with and without pCR were similar in term of age, sex, comobidities, BMI and tumor characteristics. Multivariate logistic regression indicated that pre-treatment tumor size <= 5 cm was a significant predictor for pCR (p = 0.035), whereas clinical N stage only showed a positive trend (p = 0.084). Conclusions: Tumor size at diagnosis could be used to predict pCR, and thus to individualize therapy in LARC patients management. Validation in other studies is needed

Assessment of biventricular function by three-dimensional speckle tracking echocardiography in adolescents and young adults with human immunodeficiency virus infection. a pilot study.

Background. The purpose of the study was to assess biventricular parameters of wall deformation with three-dimensional speckle tracking echocardiography (3DSTE) in adolescents and young adults with human immunodeficiency virus infection (HIV) on antiretroviral therapy in order to detect a possible subclinical myocardial dysfunction. Methods. Twenty-one patients aged 12 to 39years with HIV, 21 normal controls of the same age and sex, and 21 patients with idiopathic non-ischemic dilated cardiomyopathy (DCM) were studied with 3DSTE. All HIV patients were stable in terms of HIV infection, with no history of heart disease or other chronic systemic disease except HIV infection, and were on highly active antiretroviral therapy (HAART) with good immunological control. Standard echocardiographic measures of LV-RV function were assessed. 3D LV global longitudinal strain (GLS), circumferential strain, radial strain and LV twist (TW) were calculated. Global area strain (GAS) was calculated by 3DSTE as percentage variation in surface area defined by the longitudinal and circumferential strain vectors. 3D right ventricular (RV) global and free-wall longitudinal strain were obtained. Results. LV GLS and GAS were lower in HIV patients compared to normal controls (p=0.002, and p=0.01, respectively). There were no significant differences in LV ejection fractions between the groups. There was a weak positive correlation between LV GLS and age (r=0.215, p=0.034) and a weak negative correlation between LV GLS and nadir-CD4 T-cells count (r=0.198, p=0.043). DCM patients had more marked and widespread reduction in LV GLS and GAS compared to controls (p&lt;0.001), whereas in HIV patients LV strain impairment (p&lt;0.05) was more localized in basal and apical regions. RV free-wall longitudinal strain was significantly reduced in HIV patients when compared with the control group (p=0.03). No patient had pulmonary systolic pressure higher than 35mmHg. Conclusions. Three-dimensional speckle tracking echocardiography may help to identify HIV patients at high cardiovascular risk allowing early detection of biventricular dysfunction in the presence of normal LV ejection fraction and in the absence of pulmonary hypertension. LV strain impairment in HIV patients is less prominent and widespread compared to DCM patients

Relationships between geogenic radon potential and gamma ray maps with indoor radon levels at Caprarola municipality (central Italy)

Exposures to relatively high indoor radon (222Rn) levels represents a serious public health risk because Rn is associated with lung cancer (Darby et al., 2001; WHO, 2009; Oh et al., 2016; Sheen et al., 2016). The risk is high because radon, and its short-lived decay products in the atmosphere, contributes for about 60% of the total annual effective dose (UNSCEAR, 2000; WHO, 2009). Cancer risk is increased by smoking being almost 9 times higher than the risk to non-smokers exposed to similar levels (EPA, 2009). Due to these reasons, it is very important to assess the indoor exposure of public to radon and their daughters. Rn is a natural ubiquitous gas and its abundance is mainly controlled by the geology, and in particular by the soil and rock content of its parent nuclide (238U). Furthermore, bedrock characteristics (i.e. permeability and porosity) and also fault activity can affect the amount of Rn released in the ground (Ciotoli et al., 2007; Barnet et al., 2018). As such, in conditions of permeable and/or fractured bedrock and high uranium content, high indoor radon concentrations are expected (Bossew and Lettner, 2007; Gruber et al., 2013; Cinelli et al., 2015; Ielsch et al., 2017; Ciotoli et al., 2017). A non-natural contribution that controls the indoor Rn levels is home construction type and building materials (Vauptic et al., 2002; Appleton, 2007). Additionally, meteorological factors, such as wind, temperature and humidity, can affect the rate of Rn entry into the buildings (Porstendörfer et al., 1994; Miles et al., 2005; Schubert et al., 2018). In this work, we propose a new geospatial technique to construct the geogenic radon potential (GRP) map of the Caprarola municipality (northern Lazio, central Italy) characterized by recent (about 100 Kyr) volcanic deposits with high content in radon parent nuclides (Ciotoli et al., 2017). GRP map has been obtained by using Empirical Bayesian Kriging Regression (EBKR) technique with soil gas radon, as the response variable, and a number of proxy variables (i.e. content of the radiogenic parent nuclides, the emanation coefficient of the outcropping rocks, the diffusive 222Rn flux from the soil, the soil-gas CO2 concentration, the Digital Terrain Model (DTM), the permeability of the outcropping rocks and the gamma dose radiation of the shallow lithology. Furthermore, possible relationships between predicted soil radon values (i.e. GRP) and gamma radiation distribution with the indoor concentrations measured in private and public buildings has been investigated, respectively. The obtained results confirm that GRP maps provide the local administration of a useful tool for land use planning and that, the mapping of gamma emission, allows to a fast and effective evaluation of indoor radon hazard because it is mainly influenced by the building materials rather than other anthropic controls

&quot;Delirium Day&quot;: A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 ± 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

Alteration of sulfides within an open air waste-rock dump: application of synchrotron µ-XRD, µ-XRF, and µ-XANES analyses

We have applied a combination of synchrotron-based techniques (μ-XRD, μ-XRF, and µ-XANES) to determine the mineralogy and the elemental distribution of metals in partially altered sulphide-mineralization fragments deposited within an open-air waste-rock dump (Libiola mine, eastern Liguria, Italy). In this dump AMD processes are active and intense and sulphide-mineralized clasts progressively undergo oxidation originating centimetric-thick hardpans cemented by secondary iron oxides and oxyhydroxides. Selected samples, containing the transition from unaltered sulphides to secondary oxidation products have been analyzed along several millimetric transects. The results evidenced that sulphides (pyrite + chalcopyrite + sphalerite) oxidation starts from the crystals rims or from intra-grain microfractures. Sulphide-S firstly oxidizes to sulphate and then is rapidly leached out from the system. The altered layers are composed almost exclusively of Fe-oxides (hematite) and -oxyhydroxides (goethite and minor bernalite) that replace sulphides and fill intra- and inter-grain interstices. Elemental maps and μ-XRF transects evidenced that these secondary minerals efficiently and selectively scavenge many of the elements released during sulphides (e.g. Cu, Zn, As) and gangue minerals (e.g. Ni, Cr, Al) alteration