443 research outputs found
La barba di Solzenicyn e la frammentazione dei diritti umani.
This article is in some respects provoking. It starts using a quotation
from the famous Kundera s book on Immortality as a peg to hang a discussion
on the transformation of individual whishes into rights and on the fragmentation
sustained by human rights after the cultural revolution of 1968.
It was in that period that the evolution of modern legal and political thought
(deeply rooted in gnosticism) reached its climax, after developing through Scolastic
rationalism in the 14th century and the modern doctrines of natural law
(together with the scientific revolution) in the 16th.
Between the 18th and the 19th century the human rights went through an age of
abstractness (the Enlightment and the Déclaration in 1789) and then of socialization,
until their ultimate denial as "individual" rights in the 20th century, dominated
by totalitarian nationalism and communism (both anti-individualistic).
After the Nuremberg Trial and the rising crisis of legal positivism, the human
rights have been submitted to a process of constitutionalization and internationalization
(see UN Universal Declaration) which, however, have not been able
to cast light on their pre-normative (i.e. metaphysical) nature. In such a way
human rights remain under control of a single power (either from a nation state
or from some supranational community) instead of being founded on what is
essentially human.
It is the individualistic nature of modern human rights, strenghtened by secularization
in the post-modern age, that prevents the durable foundation of human
rights from being revealed, leaving them to the fragmentation of individual
wishes - as written in Kundera 's book.
Only a deep rethink of the (gnostic) process which has led mankind to modernity
could allow us to save the notion of "human right", bringing it from the pluralistic
fragmentation to the essence of the law
Influence of coil geometry, supply conditions and nanoparticle heating properties on magnetic hyperthermia in mouse models
For in vivo magnetic hyperthermia tests, which are typically conducted on small animal models, one of the objectives is the design of alternating current (AC) magnetic field applicators able to guarantee an effective activation of magnetic nanoparticles (MNPs). During therapy application, it is critical to optimize heat deposition due to MNPs and minimize side effects in healthy tissues. For an accurate treatment planning, it is required to carefully select the geometry of the applicator coils and their location with respect to the body, as a function of the position and size of the tumour target region. Additionally, one should preliminary estimate the impact of experimental conditions on the MNP heating efficiency and thus on their capability to induce a temperature increase in tissues. Biophysical constraints have also to be taken into account in the choice of AC magnetic field parameters (frequency and amplitude), to avoid eddy current effects as much as possible. In this study, we present realistic simulations of preclinical tests on a mouse model, evaluating thermal response under various experimental conditions. We investigate different field applicator configurations, including helical, Helmholtz and pancake coils, while also analysing the role of the amplitude and frequency of the supply current, as well as of the type and administered dose of MNPs. The temperature increase in tissues, resulting from the heating effects due to AC magnetic field exposure and MNP activation, is calculated by means of in-house finite element models that solve the low -frequency electromagnetic field problem and the bioheat transfer equation. This in silico approach, which is applicable to any type of field applicators and MNPs, has been demonstrated to provide useful insights for the optimization of in vivo experiments, enabling the design of safer and more effective treatments
Prophage association of mef(A) elements encoding efflux-mediated erythromycin resistance in Streptococcus pyogenes.
OBJECTIVES:
To compare different mef(A) elements of Streptococcus pyogenes for a possible chimeric genetic nature, i.e. a transposon inserted into a prophage.
METHODS:
Eleven S. pyogenes isolates with efflux-mediated erythromycin resistance were used. The isolates were typed using several genotypic approaches. Gene detection was performed by PCR using specific primer pairs. The mef(A) elements of the test strains were induced with mitomycin C and phage DNA was extracted. Induction was monitored by PCR using primers targeting mef(A).
RESULTS:
Six tetracycline-susceptible isolates had PCR evidence of all of the eight open reading frames (ORFs) of the Tn1207.1 element; their mef(A) element was consistent with the Tn1207.3 element in four isolates and with the 58.8 kb chimeric element in two. Five tetracycline-resistant isolates had no PCR evidence of orf1 and orf2 and showed variable patterns as to orf3, orf7, and orf8. Three ORFs placed along the conserved region downstream of Tn1207.1 in the 58.8 kb mef(A) chimeric element were detected in the six tetracycline-susceptible, but not in the five tetracycline-resistant isolates. Induction assays with mitomycin C demonstrated that the mef(A) elements of all strains tested were present in culture supernatants in a DNAse-resistant form, such as a phage capsid.
CONCLUSIONS:
All recognized mef(A) elements of S. pyogenes appear to be prophage-associated. Whereas the two elements detected in tetracycline-susceptible isolates (Tn1207.3 and the 58.8 kb one) were apparently inserted into the same prophage, the tet(O)-mef(A) element was inserted into a different prophage. Phage transfer is likely to play a critical role in the dissemination of erythromycin resistance in S. pyogenes populations
Magnetization switching in high-density magnetic nanodots by a fine-tune sputtering process on a large-area diblock copolymer mask
partially_open10Ordered magnetic nanodot arrays with extremely high density provide unique properties to the growing field of nanotechnology. To overcome the size limitations of conventional lithography, a fine-tuned sputtering deposition process on mesoporous polymeric template fabricated by diblock copolymer self-assembly is herein proposed to fabricate uniform and densely spaced nanometer-scale magnetic dot arrays. This process was successfully exploited to pattern, over a large area, sputtered Ni80Fe20 and Co thin films with thicknesses of 10 and 13 nm, respectively. Carefully tuned sputter-etching at a suitable glancing angle was performed to selectively remove the magnetic material deposited on top of the polymeric template, producing nanodot arrays (dot diameter about 17 nm). A detailed study of magnetization reversal at room temperature as a function of sputter-etching time, together with morphology investigations, was performed to confirm the synthesis of long-range ordered arrays displaying functional magnetic properties. Magnetic hysteresis loops of the obtained nanodot arrays were measured at different temperatures and interpreted via micromagnetic simulations to explore the role of dipole-dipole magnetostatic interactions between dots and the effect of magnetocrystalline anisotropy. The agreement between measurements and numerical modelling results indicates the use of the proposed synthesis technique as an innovative process in the design of large-area nanoscale arrays of functional magnetic elements.openBarrera, G; Celegato, F; Coïsson, M; Manzin, A; Ferrarese Lupi, F; Seguini, G; Boarino, L; Aprile, G; Perego, M; Tiberto, PBarrera, Gabriele; Celegato, F; Coïsson, M; Manzin, A; Ferrarese Lupi, F; Seguini, G; Boarino, L; Aprile, G; Perego, M; Tiberto,
Dynamics of Gut Microbiota and Clinical Variables after Ketogenic and Mediterranean Diets in Drug-Naïve Patients with Type 2 Diabetes Mellitus and Obesity
Type 2 diabetes mellitus (T2DM), the most common form of diabetes, is a progressive chronic metabolic disease that has increasingly spread worldwide, enhancing the mortality rate, particularly from cardiovascular diseases (CVD). Lifestyle improvement through diet and physical activity is, together with drug treatment, the cornerstone of T2DM management. The Mediterranean diet (MD), which favors a prevalence of unprocessed vegetable foods and a reduction in red meats and industrial foods, without excluding any food category, is usually recommended. Recently, scientific societies have promoted a very low-calorie ketogenic diet (VLCKD), a multiphasic protocol that limits carbohydrates and then gradually re-introduces them, with a favorable outcome on body weight and metabolic parameters. Indeed, gut microbiota (GM) modifications have been linked to overweight/obesity and metabolic alterations typical of T2DM. Diet is known to affect GM largely, but only a few studies have investigated the effects of VLCKD on GM, especially in T2DM. In this study, we have compared anthropometric, biochemical, lifestyle parameters, the quality of life, and the GM of eleven patients with recently diagnosed T2DM and overweight or obesity, randomly assigned to two groups of six and five patients who followed the VLCKD (KETO) or hypocaloric MD (MEDI) respectively; parameters were recorded at baseline (T0) and after two (T2) and three months (T3). The results showed that VLCKD had more significant beneficial effects than MD on anthropometric parameters, while biochemical improvements did not statistically differ. As for the GM, despite the lack of significant results regarding the alpha and beta diversity, and the Firmicutes/Bacteroidota ratio between the two groups, in the KETO group, a significant increase in beneficial microbial taxa such as Verrucomicrobiota phylum with its members Verrucomicrobiae, Verrucomicrobiales, Akkermansiaceae, and Akkermansia, Christensenellaceae family, Eubacterium spp., and a reduction in microbial taxa previously associated with obesity (Firmicutes and Actinobacteriota) or other diseases (Alistipes) was observed both at T2 and T3. With regards to the MEDI group, variations were limited to a significant increase in Actinobacteroidota phylum at T2 and T3 and Firmicutes phylum at T3. Moreover, a metagenomic alteration linked to some metabolic pathways was found exclusively in the KETO group. In conclusion, both dietary approaches allowed patients to improve their state of health, but VLCKD has shown better results on body composition as well as on GM profile
New observations with the gas electron multiplier (GEM)
We describe recent measurements realized with the Gas Electron Multiplier (GEM) mesh added as pre-amplification element to a multiwire and a micro-strip chamber. Large, stable combined gains are obtained, with good uniformity and energy resolution, in a wide range of filling gases including non-flammable mixtures; coupled to a micro-strip plate, the pre-amplification element allows to maintain the high rate capability and resolution at considerably lower operating voltages, completely eliminating discharge problems. Charge gains are large enough to allow detection of signals in the ionization mode on the last element, permitting the use of a simple printed circuit as read-out electrode; two-dimensional read-out can then be easily implemented. The absence of charge multiplication in the last stage avoids charge build-up on the substrate and prevents ageing phenomena. A new generation of simple, reliable and cheap fast position sensitive detectors seems at hand
Genetic diversity of Streptococcus suis clinical isolates from pigs and humans in Italy (2003-2007)
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Operation of high rate microstrip gas chambers
We describe recent measurements carried out in well controlled and reproducible conditions to help understanding the factors affecting the short and long term behaviour of Microstrip Gas Chambers. Special care has been taken concerning the gas purity and choice of materials used in the system and for the detectors construction. Detectors built on glasses with surface resistivity in the range have shown satisfactory performance as they do not show charging-up process at high rate and stand the large doses required for the future high luminosity experiments (~10 mC·cm-1·yr-1). Concerning the lifetime measurements, it has been observed that chambers manufactured on high-resistivity glass are far more susceptible of suffering ageing than detectors made on low resistivity, electron-conducting supports, independently of the metal used for the artwork (chromium or gold) at least in clean gas conditions. The successfully operation in the laboratory of detectors manufactured on diamond-coated glass with a surface resistivity around confirms the last statement. Results from a long-term, high rate beam test are also reported
Optimization of design and beam test of microstrip gas chambers
We describe recent experimental and theoretical work aimed at optimizing the geometry and the operation of micro-strip gas chambers in order to improve their performance and reliability. With the help of a simulation program, we have studied the mechanism of signal propagation and analyzed the effects on signal shape and size of resistivity of strips, grouping of biased strips and presence of a back-plane. Several detectors manufactured according to the results of the study and equipped with fast amplifiers have been installed in a test beam to study general operating characteristics, efficiency and localization accuracy; preliminary results of the data analysis are discussed
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