Computational approaches to shed light on molecular mechanisms in biological processes

Computational approaches based on Molecular Dynamics simulations, Quantum Mechanical methods and 3D Quantitative Structure-Activity Relationships were employed by computational chemistry groups at the University of Milano-Bicocca to study biological processes at the molecular level. The paper reports the methodologies adopted and the results obtained on Aryl hydrocarbon Receptor and homologous PAS proteins mechanisms, the properties of prion protein peptides, the reaction pathway of hydrogenase and peroxidase enzymes and the defibrillogenic activity of tetracyclines. © Springer-Verlag 2007

Experimental characterization of tensile strength of steel and fibre rovings also under environmental conditioning

The efficiency of the strengthening techniques by externally applied materials can be improved enhancing the debonding strength of the reinforcement from the support by the use of connectors (anchor spikes) consisting of unidirectional bundles of fibres embedded in concrete or masonry by means of organic or inorganic matrices. The use of connectors is suggested in various codes and guidelines of strengthening techniques by composite materials and provisions for their application are given, but currently there are no details for the qualification of the material. In order to investigate anchor spikes made of glass, basalt, aramid, carbon, PBO and steel, a large experimental campaign was carried out at the Materials and Structures Laboratory of the University of Sannio. The tests allowed to evaluate the mechanical characteristics (tensile strength, modulus of elasticity, deformation at the maximum load) of the anchor spikes constituted by only dry fibres, not impregnated, also as a result of environmental conditioning such as freezing and thawing, controlled humidity, alkaline and saline environment

Adverse events in thyroid surgery: observational study in three surgical units with high volume/year

Background: Thyroid surgery, performed for benign or malignant pathologies, is one of the most frequently performed procedures and its frequency has even been increasing in recent years. Postoperative bleeding, recurrent laryngeal nerve (RLN) palsy, associated to dysphonia, dysphagia, dyspnea, and hypoparathyroidism represent the most fearful and common complications. We conducted a multicenter, observational study of retrospectively collected data in three high-volume referral centers, enrolling all patients undergone to thyroid surgery between January 2016 and December 2017 in Parma University Hospital, Cagliari University Hospital and Ferrara University Hospital. Materials: Patients were divided into five groups, differentiated thyroid carcinoma, medullary thyroid carcinoma, non-toxic benign pathology, hyperfunctioning benign pathology and NIFTP (Non-invasive Follicular Thyroid neoplasm with Papillary-like nuclear features). A follow up at 7 and 30 days was executed, evaluating the onset of paresthesia, dysphonia and dysphagia. A 6-month follow-up was conducted in cases of early complications. Results: Totally, 1252 patients were eligible for the study: 907 female and 345 male, with a female to male ratio of 2.6:1 and an average age of 53.428. Total thyroidectomy was performed in 1022 cases, lobectomy in 230. After 6 months we recorded paresthesia in 0.5%, dysphonia in 1.8% and dysphagia in 0.5%. Conclusion: Our study confirms once again that a share of morbidity escapes the possibilities of prediction and control by the operator, depending on patient anamnestic, pathological or anatomical factors

Patterns and partners within the QCD phase diagram including strangeness

We review the current situation of the pattern of chiral symmetry restoration. In particular, we analyze partner degeneration for $O(4)$ and $U(1)_A$ symmetries within the context of Ward Identities and Effective Theories. The application of Ward Identities to the thermal scaling of screening masses is also discussed. We present relevant observables for which an Effective Theory description in terms of Chiral Perturbation Theory and its unitarized extension are compatible with lattice data even around the transition region. We pay special attention to the role of strangeness in this context.Comment: Proceedings of the Workshop "Strangeness in Quark Matter 2019", 6 pages, 2 figure

The SOAR optical imager: status and first results

We briefly describe the SOAR Optical Imager (SOI), the first light instrument for the 4.1m SOuthern Astronomical Research (SOAR) telescope now being commissioned on Cerro Pachón in the mountains of northern Chile. The SOI has a mini-mosaic of 2 2kx4k CCDs at its focal plane, a focal reducer camera, two filter cartridges, and a linear ADC. The instrument was designed to produce precision photometry and to fully exploit the expected superb image quality of the SOAR telescope over a 5.5x5.5 arcmin2 field with high throughput down to the atmospheric cut-off, and close reproduction of photometric pass-bands throughout 310-1050 nm. During early engineering runs in April 2004, we used the SOI to take images as part of the test program for the actively controlled primary mirror of the SOAR telescope, one of which we show in this paper. Taken just three months after the arrival of the optics in Chile, we show that the stellar images have the same diameter of 0.74" as the simultaneously measured seeing disk at the time of observation. We call our image "Engineering 1st Light" and in the near future expect to be able to produce images with diameters down to 0.3" in the R band over a 5.5' field during about 20% of the observing time, using the tip-tilt adaptive corrector we are implementing

Magnetothermodynamics of BPS baby skyrmions

The magnetothermodynamics of skyrmion type matter described by the gauged BPS baby Skyrme model at zero temperature is investigated. We prove that the BPS property of the model is preserved also for boundary conditions corresponding to an asymptotically constant magnetic field. The BPS bound and the corresponding BPS equations saturating the bound are found. Further, we show that one may introduce pressure in the gauged model by a redefinition of the superpotential. Interestingly, this is related to non-extremal type solutions in the so-called fake supersymmetry method. Finally, we compute the equation of state of magnetized BSP baby skyrmions inserted into an external constant magnetic field $H$ and under external pressure $P$, i.e., $V=V(P,H)$, where $V$ is the "volume" (area) occupied by the skyrmions. We show that the BPS baby skyrmions form a ferromagnetic medium.Comment: Latex, 39 pages, 14 figures. v2: New results and references added, physical interpretation partly change

DECam integration tests on telescope simulator

The Dark Energy Survey (DES) is a next generation optical survey aimed at measuring the expansion history of the universe using four probes: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the survey, the DES Collaboration is building the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which will be mounted at the Blanco 4-meter telescope at the Cerro Tololo Inter- American Observatory. DES will survey 5000 square degrees of the southern galactic cap in 5 filters (g, r, i, z, Y). DECam will be comprised of 74 250 micron thick fully depleted CCDs: 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. Construction of DECam is nearing completion. In order to verify that the camera meets technical specifications for DES and to reduce the time required to commission the instrument, we have constructed a full sized telescope simulator and performed full system testing and integration prior to shipping. To complete this comprehensive test phase we have simulated a DES observing run in which we have collected 4 nights worth of data. We report on the results of these unique tests performed for the DECam and its impact on the experiments progress.Comment: Proceedings of the 2nd International Conference on Technology and Instrumentation in Particle Physics (TIPP 2011). To appear in Physics Procedia. 8 pages, 3 figure

Two-color QCD via dimensional reduction

We study the thermodynamics of two-color QCD at high temperature and/or density using a dimensionally reduced superrenormalizable effective theory, formulated in terms of a coarse grained Wilson line. In the absence of quarks, the theory is required to respect the Z(2) center symmetry, while the effects of quarks of arbitrary masses and chemical potentials are introduced via soft Z(2) breaking operators. Perturbative matching of the effective theory parameters to the full theory is carried out explicitly, and it is argued how the new theory can be used to explore the phase diagram of two-color QCD.Comment: 17 pages, 1 eps figure, jheppub style; v2: minor update, references added, published versio

PT-symmetry breaking in complex nonlinear wave equations and their deformations

We investigate complex versions of the Korteweg-deVries equations and an Ito type nonlinear system with two coupled nonlinear fields. We systematically construct rational, trigonometric/hyperbolic, elliptic and soliton solutions for these models and focus in particular on physically feasible systems, that is those with real energies. The reality of the energy is usually attributed to different realisations of an antilinear symmetry, as for instance PT-symmetry. It is shown that the symmetry can be spontaneously broken in two alternative ways either by specific choices of the domain or by manipulating the parameters in the solutions of the model, thus leading to complex energies. Surprisingly the reality of the energies can be regained in some cases by a further breaking of the symmetry on the level of the Hamiltonian. In many examples some of the fixed points in the complex solution for the field undergo a Hopf bifurcation in the PT-symmetry breaking process. By employing several different variants of the symmetries we propose many classes of new invariant extensions of these models and study their properties. The reduction of some of these models yields complex quantum mechanical models previously studied.Comment: 50 pages, 39 figures (compressed in order to comply with arXiv policy; higher resolutions maybe obtained from the authors upon request

Active and passive shielding design optimization and technical solutions for deep sensitivity hard X-ray focusing telescopes

The 10-100 keV region of the electromagnetic spectrum contains the potential for a dramatic improvement in our understanding of a number of key problems in high energy astrophysics. A deep inspection of the universe in this band is on the other hand still lacking because of the demanding sensitivity (fraction of microCrab in the 20-40 keV for 1 Ms integration time) and imaging (~15" angular resolution) requirements. The mission ideas currently being proposed are based on long focal length, grazing incidence, multi-layer optics, coupled with focal plane detectors with few hundreds microns spatial resolution capability. The required large focal lengths, ranging between 8 and 50 m, can be realized by means of extendable optical benches (as foreseen e.g. for the HEXIT-SAT, NEXT and NuSTAR missions) or formation flight scenarios (e.g. Simbol-X and XEUS). While the final telescope design will require a detailed trade-off analysis between all the relevant parameters (focal length, plate scale value, angular resolution, field of view, detector size, and sensitivity degradation due to detector dead area and telescope vignetting), extreme attention must be dedicated to the background minimization. In this respect, key issues are represented by the passive baffling system, which in case of large focal lengths requires particular design assessments, and by the active/passive shielding geometries and materials. In this work, the result of a study of the expected background for a hard X-ray telescope is presented, and its implication on the required sensitivity, together with the possible implementation design concepts for active and passive shielding in the framework of future satellite missions, are discussed.Comment: 13 pages, 6 figures. Proceedings of SPIE conference "Optics for EUV, X-Ray, and Gamma-Ray Astronomy II", San Diego (CA, USA), July 31st - August 4th, 2005, Vol. 5900. Full color figures are available at http://www.bo.iasf.cnr.it/~malaguti/papers/SPIE2005_1.ps.g