47,459 research outputs found
Evaluation of occupational exposure in magnetic resonance sites
No full textPurpose: In an attempt to evaluate the exposure level of magnetic resonance imaging (MRI) workers to static magnetic fields, the isotropic magnetic flux density values were integrated over time to produce the cumulative exposure. To protect occupational staff a further precautionary step is proposed by introducing a weighting function incorporating the limits imposed by the Italian legislation. The results obtained should be reported, at the end of each working day, on a special dose card, in order to record each worker's exposure to the static magnetic field. Moreover, this dose card could be an important tool if long-term effects occur because it provides a complete history of the occupational exposure in an MRI site. Materials and methods: To conduct measurements, three Hall-sensor probes were used. The consistency of experimental data, tools and methodologies used was evaluated by performing the Kruskal-Wallis test. Finally, the weighted magnitude of the magnetic flux density was integrated over time to obtain global exposure. Results: Measurements were performed on different MRI scanners ranging from 0.25 up to 3.0 T. The results obtained were compared with the 200 mT·h, which represents the upper limit of the Italian regulation. In no case was the 200 mT·h per day exposure exceeded: however, when the strength of the magnetic field was >200 mT the weighted function overestimated the exposure, so that it represents a highly precautionary measure taking into account possible acute and long-term effects. In addition, from the data recorded during patient positioning operations by MRI staff the dB/dt curve was obtained. Conclusions: The areas obtained from the integral of the weighted static magnetic field strength over time can be indicative of the global exposure of the occupational staff. These values should be reported on a special dose card that could be considered as an important tool if long-term effects occur because it provides a complete history of the occupational exposure in an MRI site
Redox reactions of low-valent Group 4 organometallics with 9,10-phenanthrenequinone (PQ). Crystal and molecular structure of a 10-membered tetraoxometallacycle of bis(cyclopentadienyl)zirconium(IV)
No full textThe bis(arene) derivative of titanium(0), Ti(h6-toluene)2, reacts with 9,10-phenanthrenequinone (PQ) with release of tile arene ligands
and formation of a diamagnetic brown compound best formulated as a dinuclear titanium(IV) derivative containing both 9,10-phenanthrenesemiquinone
(PSQ) and 9,10-phenanthrenediolato (PDA) ligands. MCp2(CO) 2 (M = Zr, Hf) react with PQ to give MCp2PDA which
has been characterized by single crystal X-ray diffractometry for M = Zr. Crystal data: C48H 3604Zr2, M = 859.26 g mol-1, monoclinic,
space group P21/n (No. 14), a = 11.647(8), b = 17.07(1), c = 18.80(1),~, /3= 97.17(6) °, V= 3709(7)A 3, Z= 4, dcalc := 1.539gcm -3,
bt = 5.97 cm -~, F(000) = 1744. The structure consists of dinuclear [ZrCp2PDA] 2 units, the two ZrCp2 groups being bridged by the PDA
ligands to give a 10-membered tetraoxazirconacycle
Prove di funzionamento e controlli di qualità in radiodiagnostica tradizionale: considerazioni e proposte operative.
No full textEffect of Intravenous IgM-Enriched Immunoglobulins on Presepsin and Other Sepsis Biomarkers
No full textPatients in septic shock with low IgG and IgM serum concentrations have higher mortality rates compared to those with normal immunoglobulin levels and, therefore, there is a rational explanation to administer intravenous IgM-enriched immunoglobulins to septic patients in ICU. Aim of this study is to evaluate the effectiveness of intravenous IgM-enriched immunoglobulins in decreasing several sepsis biomarker concentrations. 26 sepsis patients were enrolled in this observational cohort study and Nitric Oxide, Endocan, Pentraxin and presepsin serum levels were measured during their first 3 days of ICU stay. The use of intravenous IgM-enriched immunoglobulins did not influence the temporal evolution of SOFA, Nitric Oxide, Endocan, Pentraxin and Presepsin in the first 3 days of ICU stay in a statistically significant manner, even if Presepsin decreased of 25% from day 1 to day 2 in the Pentaglobin group. It seems possible that Pentaglobin infusion reduces the Presepsin level in a more effective way if it were administered to a younger population (p = 0.012). In conclusion, age modifies the response of Presepsin to Pentaglobin and is a critical variable when investigating the effect of intravenous IgM-enriched immunoglobulins on sepsis
The tetracyclopentadienyls of titanium, zirconium and hafnium: new synthetic procedures and reactivity
No full textIn toluene as medium, the tetra(cyclopentadienyl) derivatives of Group 4 elements, MCp4 (MTi, Zr, Hf), have been prepared
in high yields from MCp2Cl2 and NaCp. The reactivity of ZrCp4 with species containing active protons such as Ph3SiOH or strong
acids has been studied. Substituted bis(cyclopentadienyl) derivatives were produced except in the case of the reaction between
ZrCp4 and CF3SO3H. In this case, the tris(cyclopentadienyl) derivative ZrCp3(CF3SO3) was obtained as a pale yellow crystalline
material, reactive with water to give the m-oxo derivative of zirconium(IV), [ZrCp2(CF3SO3)]2O, which has been characterized by
standard methods and by X-ray diffraction. Crystal data: C22H20F6O7S2Zr2, M756.96 g mol1, monoclinic, space group C2:c
(no. 15), a19.525(4), b9.028(2), c16.152(5) A°
, b107.31(2)°, V2718.2(1) A°
3, Z4, dcalc1.850 g cm3, l(Cu–Ka)
1.54184 A°
, T291 K, m85.66 cm1, F(000)1496, R0.054, Rw0.049
Prove di funzionamento e controlli di qualità in radiodiagnostica tradizionale: considerazioni e proposte operative
No full textTargeting COVID-19 prevention in hemodialysis facilities is associated with a drastic reduction in central venous catheter-related infections
No full textBackground: In hemodialysis (HD) patients, central venous catheter (CVC) related bloodstream infections are a major cause of morbidity and mortality. Hygienic precautions are a key aspect of dialysis care for infection prevention, but they are not sufficient to completely avoid the occurrence of CVC related infections. During the COVID-19 pandemic, hygienic precautions for preventing viral transmission have been markedly reinforced. We evaluated their effects on CVC-related infection rates. Methods: An observational retrospective study was conducted in two hemodialysis units of the same institution treating 215 chronic hemodialysis patients, 71 of whom are currently (33%) using a CVC. In the CVC cohort, we compared data on catheter-related infection rates during the maximum spread of the COVID-19 pandemic in Italy (February to May 2020) with data from the same period of the previous year and with the whole of 2019. Results: In 2019, we recorded a catheter-related bloodstream infection (CRBSI) rate of 1.19 (95% CI 0.81–1.68)/1000 days [2.07 (95% CI 1.12–3.52)/1000 days in the Feb-May 2019 period] and a tunnel and exit-site infection rate of 0.82 (95% CI 0.51–1.24)/1000 days [1.04 (95% CI 0.41–2.15)/1000 days in the Feb–May 2019 period]. Infection rates drastically decreased during the COVID-19 pandemic, with just one catheter-related bloodstream infection being recorded. Catheter-related bloodstream infection rates showed a significant reduction to 0.20 (95% CI 0.01–0.9)/1000 days (p < 0.05 and p < 0.005 compared to 2019 and to Feb-May 2019, respectively) and a non-significant reduction in tunnel and exit-site infections to 0.6 (95% CI 0.15–1.6)/1000 days. Conclusions: The observed 91% reduction in catheter-related bloodstream infections compared to the same period in 2019 [IRR 0.09 (95% CI 0.002–0.64)] and the 83% reduction compared to the whole of 2019 [IRR 0.17 (95% CI 0.004–1.009)] suggest that a stricter implementation of hygienic precautions in the dialysis setting can markedly improve the problem of CVC-related infections. Graphic abstract: [Figure not available: see fulltext.
Distance from the outbreak of infection, ozone pollution and public health consequences of SARS-CoV-2 epidemic: the HOPE method
No full textBACKGROUND: Italy was the second country in the world, after China, to be hit by SARS-CoV-2 pandemic. Italy's experience teaches that steps to limit people's movement by imposing 'red zones' need to be put in place early by carefully identifying the cities to be included within these areas of quarantine. The assessment of the relationship between the distance from an established outbreak of SARS-CoV-2 infection with transmission-linked cases and mortality observed in other sites could provide useful information to identify the optimal radius of red zones. METHODS: We investigated the relationship between SARS-CoV-2 cases and the distance of each Italian province from the first outbreak of SARS-CoV-2 epidemic in Italy (the city of Lodi placed in the Lombardia region). In 38 provinces of Lombardia and neighboring regions, we performed a breakpoint analysis to identify the radius of the red zone around Lodi minimizing epidemic spread and mortality in neighboring cities. RESULTS: In all Italian provinces, a non-linear relationship was found between SARS-CoV-2 cases and distance from Lodi. In an analysis including the provinces of Lombardia and neighboring regions, SARS-CoV-2 cases and mortality increased when the distance from Lodi reduced below 92 and 140 km, respectively, and such relationships were amplified by ozone (O3) pollution. CONCLUSIONS: The breakpoint analysis identifies the radius around the outbreak of Lodi minimizing the public health consequences of SARS-CoV-2 in neighboring cities. Such an approach can be useful to identify the red zones in future epidemics due to highly infective pathogens similar to SARS-CoV-2
Pulmonary congestion predicts cardiac events and mortality in ESRD
No full textPulmonary congestion is highly prevalent and often asymptomatic among patients with ESRD treated with hemodialysis, but whether its presence predicts clinical outcomes is unknown. Here, we tested the prognostic value of extravascular lung water measured by a simple, well validated ultrasound B-lines score (BLUS) in a multicenter study that enrolled 392 hemodialysis patients.We detected moderate-to-severe lung congestion in 45% and very severe congestion in 14% of the patients. Among those patients with moderate-to-severe lung congestion, 71% were asymptomatic or presented slight symptoms of heart failure. Compared with those patients having mild or no congestion, patients with very severe congestion had a 4.2-fold risk of death (HR=4.20, 95% CI=2.45-7.23) and a 3.2-fold risk of cardiac events (HR=3.20, 95% CI=1.75-5.88) adjusted for NYHA class and other risk factors. Including the degree of pulmonary congestion in the model significantly improved the risk reclassification for cardiac events by 10% (P<0.015). In summary, lung ultrasound can detect asymptomatic pulmonary congestion in hemodialysis patients, and the resulting BL-US score is a strong, independent predictor of death and cardiac events in this population. Copyright © 2013 by the American Society of Nephrology
Conservation and biology of triturus italicus in Italy (amphibia, salamandridae)
No full textWe sampled 154 sites of Triturus italicus from central and southern Italy to infer conservation guidelines. In most sites, the species lives in small populations (tens of individuals) in natural (ponds, pools, streams) and artificial (ditches, wells, tanks, troughs) bodies of water. Its biological cycle regarding in-water movements and reproductive patterns is very variable. The species seems in decline, with the exception of Latium and Calabria, and 22 populations have become extinct. The main causes of the species disappearance are likely due to loss of habitats caused by trasformation or destruction of bodies of water by modern farming techniques, pollution, and introduction of allochtonous species (such as fishes and pond turtles). A status of “endangered” is suggested for the species, or “vulnerable” for the populations of Latium and Calabria. The species deserves a conservation plan which includes measures such as habitat protection, scientific monitoring aimed at abundance and genetic analysis, and the creation of corridors to allow genetic exchange. The protection and restoration of small artifical bodies of water could help reach these objectives. © 2004 Taylor & Francis Group, LLC
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