594 research outputs found
Combining molecular targeted agents with radiation therapy for malignant gliomas
No full textThe expansion in understanding the molecular biology that characterizes cancer cells has led to the rapid development of new agents to target important molecular pathways associated with aberrant activation or suppression of cellular signal transduction pathways involved in gliomagenesis, including epidermal growth factor receptor, vascular endothelial growth factor receptor, mammalian target of rapamycin, and integrins signaling pathways. The use of antiangiogenic agent bevacizumab, epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib, mammalian target of rapamycin inhibitors temsirolimus and everolimus, and integrin inhibitor cilengitide, in combination with radiation therapy, has been supported by encouraging preclinical data, resulting in a rapid translation into clinical trials. Currently, the majority of published clinical studies on the use of these agents in combination with radiation and cytotoxic therapies have shown only modest survival benefits at best. Tumor heterogeneity and genetic instability may, at least in part, explain the poor results observed with a single-target approach. Much remains to be learned regarding the optimal combination of targeted agents with conventional chemoradiation, including the use of multipathways-targeted therapies, the selection of patients who may benefit from combined treatments based on molecular biomarkers, and the verification of effective blockade of signaling pathways. © 2013 Scaringi et al
Towards a chemo-mechanical approach to landslide stabilization
No full textClay-rich soils are widespread throughout the globe. Their mechanical properties can be deeply affected by the chemical composition of the pore fluid. As an example, Fig. 1a shows the residual friction angle evaluated on specimens of an illitic soil of marine origin, in equilibrium with the natural pore fluid, with distilled water or with two different salt solutions at different concentrations. In loessic soils too, which can contain up to 30% of clay – mainly illite – the magnitude of the chemo-mechanical effects has been shown to be noticeable (Fig. 1b). Several Authors (see Scaringi, 2016) hypothesized connections between changes in pore fluid chemistry and activity of some types of landslides in clay soils. In a slow earthflow in a marine clay formation, Di Maio et al. (2015) showed that the pore ion concentration can decrease significantly from the depth towards the ground surface (Fig. 1c). Thus, different parts of the landslide shear zone may exhibit different values of shear strength parameters. Natural and anthropic processes (e.g. exposure to rain water, irrigation water, freshwater from confining aquifers) can cause the concentration to decrease further over time, leading to further weakening which can produce shear displacements (Di Maio and Scaringi, 2016). On the other hand, an increase of pore solution concentration, e.g. through ion diffusion from salt piles (Di Maio et al., 2016; 2017) can produce strength increase (as in Fig. 1a). The role of chemo-mechanical coupling in the initiation and movement of landslides in clay soils should be evaluated explicitly, as it can be fundamental for a correct assessment and management of the landslide risk. Furthermore, applications of the chemo-mechanical concepts can lead to innovative and environment-friendly solutions of landslide stabilization, based, for instance, on engineered modifications of the clay behavior driven through the pore fluid chemistry
Influence of Displacement Rate on Residual Shear Strength of Clays
No full textThis paper reports on the results of direct shear tests carried out under controlled displacement rate in the range of 10-4 -
102 mm/min, under different normal stresses, with different shear devices. The tests were carried out on a kaolin, a bentonite,
their mixtures with sand at various percentages, and the clayey soil of the Costa della Gaveta earthflow. The tests were
performed on specimens reconstituted with distilled water as well as with NaCl solutions at various concentrations. Positive rate
effects were exhibited by mixtures with c.f. higher than 50% and, consistently, by the natural clayey soil the c.f. of which is about
50%. The residual shear strength increases significantly for shear displacement rate higher than about 1 mm/min. The rate effect
increases with the pore solution concentration. The residual shear strength independence of displacement rate has been confirmed
in the range 10-6 - 10-1 mm/min by the results of shear tests performed under controlled shear stress, with varying chemical
conditions of the pore fluid
Effect of inactivated C. albicans on natural killer (NK) cell activity and blastogenesis in mice. P. Marconi, L. Scaringi, A. Cassone, L. Tissi. In: Genetic and Phenotypic Markers of Tumors, (S.A. Aaronson, L. Frati and R. Verna Eds.). Plenum Publishing Corp., New York, London, pp. 145-151, 1985.
No full text11th IAEG Asian Regional Conference (ARC-11)
No full textClay-rich soils are widespread throughout the globe. Their
mechanical properties can be deeply affected by the chemical
composition of the pore fluid. As an example, Fig. 1a shows
the residual friction angle evaluated on specimens of an illitic
soil of marine origin, in equilibrium with the natural pore fluid,
with distilled water or with two different salt solutions at
different concentrations. In loessic soils too, which can contain
up to 30% of clay (mainly illite), the magnitude of the chemomechanical effects has been shown to be noticeable (Fig. 1b).
Several Authors (Scaringi, 2016) hypothesized connections
between changes in pore fluid chemistry and activity of some
types of landslides in clay soils. In a slow earthflow in a
marine clay formation, Di Maio et al. (2015) showed that the
pore ion concentration can decrease significantly from the
depth towards the ground surface (Fig. 1c). Thus, different
parts of the landslide shear zone may exhibit different values
of shear strength parameters. Natural and anthropic processes
(e.g. exposure to rain water, irrigation water, freshwater from
confining aquifers) can cause the concentration to decrease
further over time, leading to further weakening which can
produce shear displacements (Di Maio and Scaringi, 2016). On
the other hand, an increase of pore solution concentration, e.g.
through ion diffusion from salt piles (Di Maio et al., 2016;
2017) can produce strength increase (as in Fig. 1a). The role of
chemo-mechanical coupling in the initiation and movement of
landslides in clay soils should be evaluated explicitly, as it can
be fundamental for a correct assessment and management of
the landslide risk. Furthermore, applications of the chemomechanical concepts can lead to innovative and environmentfriendly solutions of landslide stabilization, based, for instance,
on engineered modifications of the clay behavior driven
through the pore fluid chemistry
Astronomical Data Mining with Neural Networks
No full textWe give a brief overview of artificial neural networks (ANNs), focusing on Kohonen networks (KNs). The two kinds of KNs will be described in detail: the unsupervised self-organizing map (SOM) and the supervised learning vector quantization (LVQ). We then apply these algorithms to two astronomical classification problems: the classification of broad absorption line quasars (BALQSOs) and of gamma-ray bursts (GRBs). In the context of BALQSOs, we find a BALQSO fraction of 10.4%, and compile a catalogue from the Sloan Digital Sky Survey (SDSS) using the supervised LVQ. This is currently the most complete BALQSO catalogue. We then apply the unsupervised SOM to GRB light curves obtained from the Burst and Transient Source Experiment (BATSE). Using only shape-dependent variables, we find that two classes are recovered: single-pulsed bursts (SPBs) and multi-pulsed bursts (MPBs). We show that these two network classes also have different observational properties that are independent of light curve shape (T90 and fluence), suggesting an intrinsic difference between the two. We conclude with some attempts to correlate our GRB result to previous studies and suggest improvements for future work
Intratympanic therapy for Ménière's disease: Effect of administration of low concentration of gentamicin
No full textWe present results at 2 years follow-up of a group of 15 patients with Ménière's disease treated with a low concentration of intratympanic gentamicin (IG group), compared with a group of 15 patients who refused any surgical treatment (NH group). IG was administered according to a predetermined and fixed schedule consisting of 2 doses of 0.5 ml gentamicin solution, pH 7.8, injected once a week, with a drug concentration of 20 mg/ml; the total dose of gentamicin was ≤ 20 mg. Additional doses of IG were administered only in patients who had recurrence of vertigo. The results were evaluated following the American Academy of Otolaryngology Head and Neck Surgery 1995 criteria for reporting Ménière's disease treatment results by means of interviews, audiologic and vestibular evaluations, and a questionnaire based on a six-point functional level scale. Seven of the 15 IG patients had recurrence of vertigo after the second injection and received a third dose of IG. Four patients had recurrence of vertigo after the third infiltration; three subjects received a fourth dose and one refused additional injection. At 2 years follow-up, 93% of the IG patients had complete (class A) or substantial (class B) control of vertigo. Only 47% of the NH patients had no vertigo or were substantially improved. Hearing deteriorated in 7% of the IG group and in 40% of the NH group. Tinnitus disappeared or improved in 20% of the IG patients and in 27% of the NH patients; 40% of the IG patients and 27% of the NH patients reported that their aural pressure was abolished. The present study demonstrates that, in patients with Ménière's disease, 0.5 ml doses of gentamicin solution, with a concentration of 20 mg/ml, injected intratympanically once a week minimize the risk of hearing loss in the treated ear, permitting complete control of vertigo in more than half of cases after 2 doses and in almost all subjects (93%) after 4 doses
Effect of ipsilateral and contralateral low-frequency narrow-band noise on temporary threshold shift in humans
No full textObjective - To evaluate the effect of ipsilateral and contralateral low-frequency (250 Hz) narrow-band noise (NBN) on the temporary threshold shift (TTS) induced by a 2 kHz tone in young normally hearing subjects with a functioning auditory efferent system. Material and Methods - Sixteen young volunteers served as subjects. All the subjects were young (20-30 years), disease-free and had a medical history negative for otological disease, noise exposure and use of ototoxic drugs. They had normal hearing [thresholds of 125-8000 Hz below 20 dB hearing level (HL)], transient-evoked otoacoustic emissions and contralateral suppression. The subjects were randomly assigned to one of three different groups. Subjects in Group A (n = 5) were exposed to a 90 dB HL 2 kHz pure tone for 10 min. Subjects in Group B (n = 6) were exposed to a 90 dB HL 2 kHz pure tone and an ipsilateral 45 dB HL 250 Hz NBN for 10 min. Subjects in Group C (n = 5) were exposed to a 90 dB HL 2 kHz pure tone and a contralateral 45 dB HL 250 Hz NBN for 10 min. The right ear served as the test ear. The TTS 2 min after the end of the exposure (TTS2) was measured in all subjects at 2, 3 and 4 kHz. Results - TTS2 in Group A was significantly higher at 3 kHz (p = 0.011) and at 4 kHz (p = 0.003) than TTS2 in Group B. At 4 kHz, TTS2 in Group C was significantly higher (p = 0.013) than TTS2 in Group B. Although TTS2 in Group C was lower than TTS2 in Group A, this difference was not significant. The presence of an ipsilateral low-frequency NBN significantly reduced TTS2 induced by a 90 dB HL 2 kHz tone. A contralateral low-frequency NBN reduced TTS2 in this group of subjects; however, the reduction was not significant. Conclusion - The results of this study show that an ipsilateral low-intensity, low-frequency (250 Hz) NBN can give protection from a TTS induced by a 2 kHz tone. Contralateral low-frequency NBN did not induce any protective effect
Effects of efferent acoustic reflex activation on psychoacoustical tuning curves in humans
No full textFrom the gut to the brain: effects of bowel inflammation on synaptic transmission and glial properties
No full textInflammatory bowel diseases (IBD) affect the gastrointestinal tract and can lead to extra-intestinal manifestations associated with cerebral function, including depression and anxiety. Previous studies have shown that during acute inflammation, different brain areas, including hippocampus, undergo alterations in glial properties and glutamatergic synaptic transmission, along with impairment of blood-brain barrier (BBB) permeability, leading to immune cell infiltration and increase of cytokines levels. However, a comprehensive understanding of the mechanisms involved remains elusive. This study aims to elucidate the cellular and molecular mechanisms underlying the alterations in the central nervous system. Using a murine model of acute peripheral inflammation induced by 2,4-Dinitrobenzenesulfonic acid hydrate (DNBS), we explored the impact of the gut-brain axis on cerebral function and identified potential mediators of central dysfunction. Through transcriptomic and immunofluorescence analyses, we show that colitis induces neuroinflammation and glial reactivity. In addition, by means of electrophysiological recordings, we assessed the effects of bowel inflammation on excitatory and inhibitory synaptic transmission in the hippocampus. Finally, we investigated the molecular mechanisms underlying the hippocampal alterations induced by colitis through metabolomic analysis. Our findings reveal significant changes in the hippocampal transcriptome, glial reactivity, and synaptic transmission, as well as changes in gut and hippocampal metabolites in the DNBS model. In conclusion, our study demonstrates that bowel inflammation and dysbiosis are associated with hippocampal dysfunctions, providing new perspectives for future investigations
- …
