114 research outputs found

    Seasonal trends and spatial variations of PM10-bounded polycyclic aromatic hydrocarbons in Veneto Region, Northeast Italy

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    The Veneto Region extends for ~18.4·103km2 in the northeastern part of the Po Valley and includes mountains, hills, plain and coastal environments with very different and discontinuous anthropogenic pressures. Although many efforts have been made to mitigate air pollution, the European air quality standards for atmospheric pollutants are frequently breached. This study investigates the levels of eight PM10-bound PAHs collected in 21 stations categorized as rural background, urban and suburban backgrounds, traffic and industrial hot-spots during one year (2011). Data were statistically processed to detect the PAH seasonal trends, their relationship with other air pollutants and micro-meteorological parameters and the space variations at a regional scale. Results show that PAHs levels are relatively high in the largest part of the region, with 10 sites exceeding the levels of BaP targeted by the European legislation. Two sites exhibited anomalously high PAHs concentrations and this anomaly became even more evident when considering the population density as a surrogate for the potential anthropogenic pressure. The PAHs levels were found directly proportional to other gaseous pollutants (CO, NO, NOx, SO2) suggesting common polluting sources. The analysis of time trends of PAH concentrations reveals significant coincidences throughout the region, i.e. simultaneous changes are observed in most sites as a consequence of similar emission sources and accumulation/removal processes. In this scenario, the control strategies currently imposed at local level (e.g. traffic limitations) have proven scarcely effective in mitigating air pollution and a real coordination at regional or even interregional level cannot be further postponed. Peculiar features of the PAHs pollution in the Veneto were also identified and some measures for protecting the human health were suggested

    Relatively oxidized conditions for diamond formation at Udachnaya (Siberia)

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    Thanks to the physical strength of diamonds and their relatively unreactive chemical nature, their mineral inclusions may remain exceptionally preserved from alteration processes and chemical exchanges with surrounding minerals, fluids and/or melts following diamond formation. Cr-bearing spinels are relatively common inclusions found in peridotitic diamonds and important oxybarometers providing information about the oxygen fugacity (fO2) of their source mantle rocks. Here, we investigated a magnesiochromite-olivine touching pair in a diamond from the Udachnaya kimberlite (Siberia) by in situ single-crystal X-ray diffraction and energy-domain synchrotron Mossbauer spectroscopy, aiming to constrain the physical-chemical conditions of diamond formation and to explore the redox state of this portion of the Siberian craton when the diamond was formed. The P-T-fO(2) entrapment conditions of the inclusion pair, determined by thermo- and oxybarometric analyses, are similar to 5.7(0.4) GPa and similar to 1015(50) ? (although entrapment at higher T and re-equilibration during subsequent mantle storage are also possible) and fO(2) near the enstatite-magnesite-olivine-diamond (EMOD) buffer. The determined fO(2) is similar to, or slightly more oxidized than, those of xenoliths from Udachnaya, but whilst the xenoliths last equilibrated with the surrounding mantle just prior to their entrainment in the kimberlite at similar to 360 Ma, the last equilibration of the inclusion pair is much older, occurring at 3.5-3.1, similar to 2 or similar to 1.8 Ga before final encapsulation in its host diamond. Hence, the similarity between xenoliths and inclusion fO(2) values indicates that the modern redox state of this portion of the Siberian lithosphere was likely attained relatively early after its formation and may have persisted for billions of years after diamond formation, at least at the local scale. Moreover, the oxygen fugacity determination for the inclusion pair provides direct evidence of diamond formation near the EMOD buffer and is consistent with recent models suggesting relatively oxidized, water-rich CHO fluids as the most likely parents for lithospheric diamonds

    The impact of COVID-19 on radiological findings in patients accessing the emergency department: a multicentric study

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    The aim of this multicentric study is to illustrate how the COVID-19 pandemic lockdown affected the workload and outcomes of radiological examinations in emergency radiology

    Human coronary inflammation by computed tomography: Relationship with coronary microvascular dysfunction

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    Background A new imaging metric using coronary computed tomography angiography (CCTA), addressing the peri-coronary adipose tissue (PCAT) computed tomography (CT) attenuation, has been clinically validated. This method provides information regarding coronary inflammation. It is unclear how coronary inflammation affects microvascular function. The non-invasive evaluation of coronary flow velocity reserve is widely used in clinical practice using Doppler measurement on the left anterior descending coronary artery (CFVR-lad) during stress-echocardiography (SE). We hypothesize that coronary inflammation affects CFVR-lad and, in the absence of overt CAD, they are significantly correlated. Methods We evaluated the relationship between coronary inflammation (by PCAT CT attenuation) and coronary microvascular function (by CFVR-lad) in subjects with no or non-obstructive (diameter stenosis <70%) coronary artery disease (CAD). Results Two-hundred and two subjects were enrolled in the study. The relationship between PCAT CT attenuation and CFVR-lad show a significant inverse relationship in the entire group of subjects enrolled in the study (r = −0.32, p < 0.001). Correlation between PCAT CT attenuation and CFVR-lad was significant in subjects with no or mild CAD-lad, while this was not the case in subjects with intermediate CAD-lad. The R and R2 were respectively −0.40, −0.16 in subjects without CAD (p < 0.001) and − 0.35 and − 0.12 in subjects with mild CAD-lad (p = 0.001). Conclusions The main finding of the current study is the independent relationship between coronary microvascular function, by Doppler CFVR-lad during SE, in subjects without severely obstructive CAD in the left anterior descending coronary artery, and the level of local coronary inflammation, by PCAT attenuation measurement on CCTA

    Decreased VLDL-Apo B 100 fractional synthesis rate despite hypertriglyceridemia in subjects with type 2 diabetes and nephropathy

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    Subjects with Type 2 Diabetes Mellitus (T2DM) and diabetic nephropathy (DN) often exhibit hypertriglyceridemia. The mechanism(s) of such an increase are poorly known. OBJECTIVE: We investigated VLDL-Apo B 100 kinetics in T2DM subjects with and without DN, and in healthy controls. DESIGN: Stable isotope 13C-leucine infusion, and modelling analysis of tracer-to-tracee ratio dynamics in the protein product pool in the 6-8 hr period following tracer infusion, were employed. SETTING: Male subjects affected by T2DM, either with (n=9) or without (n=5) DN, and healthy male controls (n=6), were studied under spontaneous glycemic levels in the post-absorptive state. RESULTS: In the T2DM patients with DN, plasma triglyceride (TG) (2.2\ub10.8 mmol/L, Mean\ub1SD) and VLDL-Apo B 100 (17.4\ub110.4 mg/dl) concentrations, and VLDL-Apo B 100 pool (0.56\ub10.29 g), were 3e60-80% greater (p<0.05 or less) than those of the T2DM subjects without DN (TG: 1.4\ub10.5 mmol/L; VLDL-Apo B 100: 9.9\ub12.5 mg/dl; VLDL-Apo B 100 pool: 0.36\ub10.09 g), and 3e80-110% greater (p<0.04 or less) than those of nondiabetic controls (TG: 1.2\ub10.4 mmol/L; VLDL-Apo B 100: 8.2\ub11.7 mg/dl; VLDL-Apo B 100: 0.32\ub10.09 g). In sharp contrast however, in the subjects with T2DM and DN, VLDL-Apo B 100 FSR was 6550% lower (4.8\ub12.2 pools/day) than that of either the T2DM subjects without DN (9.9\ub14.3 pools/day, p<0.025) or the control subjects (12.5\ub19.1 pools/day, p<0.04). CONCLUSIONS: The hypertriglyceridemia of T2DM patients with DN is not due to hepatic VLDL-Apo B 100 overproduction, which is decreased, but it should be attributed to decreased apolipoprotein removal

    Diamond-inclusion system recording old deep lithosphere conditions at Udachnaya (Siberia)

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    Diamonds and their inclusions are unique fragments of deep Earth, which provide rare samples from inaccessible portions of our planet. Inclusion-free diamonds cannot provide information on depth of formation, which could be crucial to understand how the carbon cycle operated in the past. Inclusions in diamonds, which remain uncorrupted over geological times, may instead provide direct records of deep Earth’s evolution. Here, we applied elastic geothermobarometry to a diamond-magnesiochromite (mchr) host-inclusion pair from the Udachnaya kimberlite (Siberia, Russia), one of the most important sources of natural diamonds. By combining X-ray diffraction and Fourier-transform infrared spectroscopy data with a new elastic model, we obtained entrapment conditions, Ptrap = 6.5(2) GPa and Ttrap = 1125(32)–1140(33) °C, for the mchr inclusion. These conditions fall on a ca. 35 mW/m2 geotherm and are colder than the great majority of mantle xenoliths from similar depth in the same kimberlite. Our results indicate that cold cratonic conditions persisted for billions of years to at least 200 km in the local lithosphere. The composition of the mchr also indicates that at this depth the lithosphere was, at least locally, ultra-depleted at the time of diamond formation, as opposed to the melt-metasomatized, enriched composition of most xenoliths

    T. brucei Infection Reduces B Lymphopoiesis in Bone Marrow and Truncates Compensatory Splenic Lymphopoiesis through Transitional B-Cell Apoptosis

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    African trypanosomes of the Trypanosoma brucei species are extracellular protozoan parasites that cause the deadly disease African trypanosomiasis in humans and contribute to the animal counterpart, Nagana. Trypanosome clearance from the bloodstream is mediated by antibodies specific for their Variant Surface Glycoprotein (VSG) coat antigens. However, T. brucei infection induces polyclonal B cell activation, B cell clonal exhaustion, sustained depletion of mature splenic Marginal Zone B (MZB) and Follicular B (FoB) cells, and destruction of the B-cell memory compartment. To determine how trypanosome infection compromises the humoral immune defense system we used a C57BL/6 T. brucei AnTat 1.1 mouse model and multicolor flow cytometry to document B cell development and maturation during infection. Our results show a more than 95% reduction in B cell precursor numbers from the CLP, pre-pro-B, pro-B, pre-B and immature B cell stages in the bone marrow. In the spleen, T. brucei induces extramedullary B lymphopoiesis as evidenced by significant increases in HSC-LMPP, CLP, pre-pro-B, pro-B and pre-B cell populations. However, final B cell maturation is abrogated by infection-induced apoptosis of transitional B cells of both the T1 and T2 populations which is not uniquely dependent on TNF-, Fas-, or prostaglandin-dependent death pathways. Results obtained from ex vivo co-cultures of living bloodstream form trypanosomes and splenocytes demonstrate that trypanosome surface coat-dependent contact with T1/2 B cells triggers their deletion. We conclude that infection-induced and possibly parasite-contact dependent deletion of transitional B cells prevents replenishment of mature B cell compartments during infection thus contributing to a loss of the host's capacity to sustain antibody responses against recurring parasitemic waves
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