175 research outputs found
Weathering Effects on Engineering Geological Properties of Trachydacitic Volcanic Rocks from the Monte Amiata (Southern Tuscany, Italy)
Variability in lithology and weathering degree affects physical and mechanical properties
of rocks. In this study, we investigated the relationships between weathering degree and engineering
geological properties of trachydacitic volcanic rocks from Monte Amiata (central Italy) by coupling
field and laboratory analyses. We collected in situ Schmidt hammer tests in the field. We evaluated
weathering quantifying the percentage of secondary minerals through thermal analysis in the
laboratory. We also determined dry density (rd), specific gravity of solids (Gs), porosity (n) and
two-dimensional (2D) porosity as resulted from scanning electron microscopy investigations. The
results of our study indicate a negative linear correlation between Schmidt hammer rebound values
and secondary mineral percentage. This correlation provides a tool to quantitatively estimate the
deterioration of rock uniaxial compressive strength (UCS) as weathering increases. Moreover, thermal
analysis turned out to be a quantitative and reproducible method to evaluate weathering degree of
magmatic rocks
Umbilical vein blood flow in fetuses with normal and lean umbilical cord
Objective: To evaluate whether umbilical vascular coiling is correlated with the umbilical vein blood flow profile and to investigate if this is different between fetuses with a lean and those with a normal umbilical cord. Methods: Consecutive women with a singleton gestation who delivered at term and who underwent an ultrasound examination within 24 h from delivery were studied. Umbilical cord and vessel areas were calculated. Umbilical vein blood flow parameters were obtained by digital color Doppler velocity profile integration. After delivery, the umbilical coiling index was calculated. Results: One hundred and sixteen women were studied. Twelve (10.3%) had a lean umbilical cord (area < 10th centile). A significant correlation was found between the umbilical coiling index and the umbilical vein blood flow (r = 0.67, P < 0.001). A significant difference between fetuses with and without a lean cord was found in terms of: umbilical coiling index (0.18 ± 0.08 vs. 0.29 ± 0.09, P < 0.005), cord area (87.6 ± 5.1 mm2 vs. 200.6 ± 34.6 mm2, P < 0.001), Wharton's jelly amount (25.7 ± 10.3 mm2 vs. 122.1 ± 33.4 mm2, P < 0.001), umbilical vein blood flow (93.7 ± 17.8 ml/kg per min vs. 126.0 ± 23.4 ml/kg per min, P < 0.001), and umbilical vein blood flow mean velocity (6.6 ± 2.7 cm/s vs. 9.0 ± 3.6 cm/s, P < 0.05). The proportion of fetuses with an umbilical vein blood flow < 80 ml/kg per min was higher when the cord was lean than when it was normal (25% vs. 1.9%, P < 0.01). Conclusions: Lean umbilical cords differ from normal cords not only from a structural point of view but also in the umbilical vein blood flow characteristics. This could explain the increased incidence of intrapartum complications and fetal growth restriction among fetuses with a lean and/or hypocoiled cord
Maintenance and Consolidation Therapy in Patients with Unresectable Stage III/IV Non-Small Cell Lung Cancer
Lung cancer remains the most common cancer and the leading cause of cancer-related mortality. Despite continuing improvements in chemoradiotherapy regimens and the recent clinical validation of particular agents as maintenance treatments in advanced disease, there remains an unmet need for new therapies with clinically proven value in the treatment of unresectable stage III NSCLC. Studies are under way to determine whether the use of anticancer vaccines may be an effective strategy in the treatment of NSCLC
DSA-10: A prototype array for localizing fast radio bursts
The Deep Synoptic Array 10 dish prototype is an instrument designed to detect
and localise fast radio bursts with arcsecond accuracy in real time. Deployed
at Owens Valley Radio Observatory, it consists of ten 4.5m diameter dishes,
equipped with a 250MHz bandwidth dual polarisation receiver, centered at
1.4GHz. The 20 input signals are digitised and field programmable gate arrays
are used to transform the data to the frequency domain and transmit it over
ethernet. A series of computer servers buffer both raw data samples and perform
a real time search for fast radio bursts on the incoherent sum of all inputs.
If a pulse is detected, the raw data surrounding the pulse is written to disk
for coherent processing and imaging. The prototype system was operational from
June 2017 - February 2018 conducting a drift scan search. Giant pulses from the
Crab pulsar were used to test the detection and imaging pipelines. The 10-dish
prototype system was brought online again in March 2019, and will gradually be
replaced with the new DSA-110, a 110-dish system, over the next two years to
improve sensitivity and localisation accuracy.Comment: 10 pages, 13 figures, accepted by MNRA
Socio-demographic and clinical characterization of patients with obsessive-compulsive tic-related disorder (OCTD) : An Italian multicenter study
© Copyright by Pacini Editore SrlIn the DSM-5 a new "tic-related" specifier for obsessive compulsive disorder (OCD) has been introduced, highlighting the importance of an accurate characterization of patients suffering from obsessive-compulsive tic-related disorder ("OCTD"). In order to characterize OCTD from a socio-demographic and clinical perspective, the present multicenter study was carried out. The sample consists of 266 patients, divided in two groups with lifetime diagnoses of OCD and OCTD, respectively. OCTD vs OCD patients showed a significant male prevalence (68.5% vs 48.5%; p < .001), a higher rate of psychiatric comorbidities (69.4 vs 50%; p < .001) - mainly with neurodevelopmental disorders (24 vs 0%; p < .001), a lower education level and professional status (middle school diploma: 25 vs 7.6%; full-Time job 44.4 vs 58%; p < .001). Moreover, OCTD vs OCD patients showed significantly earlier age of OCD and psychiatric comorbidity onsets (16.1 ± 10.8 vs 22.1 ± 9.5 years; p < .001, and 18.3 ± 12.8 vs 25.6 ± 9.4: p < .001, respectively). Patients with OCTD patients were treated mainly with antipsychotic and with a low rate of benzodiazepine (74.2 vs 38.2% and 20.2 vs 31.3%, respectively; p < .001). Finally, OCTD vs OCD patients showed higher rates of partial treatment response (58.1 vs 38%; p < .001), lower rates of current remission (35.5 vs 54.8%; p < .001) and higher rates of suicidal ideation (63.2 vs 41.7%; p < .001) and attempts (28.9 vs 8.3%; p < .001). Patients with OCTD report several unfavorable socio-demographic and clinical characteristics compared to OCD patients without a history of tic. Additional studies on larger sample are needed to further characterize OCTD patients from clinical and therapeutic perspectives.Peer reviewedFinal Published versio
A fast radio burst localised to a massive galaxy
Intense, millisecond-duration bursts of radio waves have been detected from beyond the Milky Way [1]. Their extragalactic origins are evidenced by their large dispersion measures, which are greater than expected for propagation through the Milky Way interstellar medium alone, and imply contributions from the intergalactic medium and potentially host galaxies [2]. Although several theories exist for the sources of these fast radio bursts, their intensities, durations and temporal structures suggest coherent emission from highly magnetised plasma [3,4]. Two sources have been observed to repeat [5,6], and one repeater (FRB 121102) has been localised to the largest star-forming region of a dwarf galaxy at a cosmological redshift of 0.19 [7, 8]. However, the host galaxies and distances of the so far non-repeating fast radio bursts are yet to be identified. Unlike repeating sources, these events must be observed with an interferometer with sufficient spatial resolution for arcsecond localisation at the time of discovery. Here we report the localisation of a fast radio burst (FRB 190523) to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66. This galaxy is in stark contrast to the host of FRB 121102, being a thousand times more massive, with a greater than hundred times lower specific star-formation rate. The properties of this galaxy highlight the possibility of a channel for FRB production associated with older stellar populations
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