Nonadiabatic high-Tc superconductivity in hole-doped fullerenes

In this paper we address the possibility of high-T-c superconductivity (T(c)similar to100 K) in hypothetical hole doped C-60 within the context of the nonadiabatic theory of superconductivity. Our analysis shows that electron doped fullerenes, represented by the A(3)C(60) family, are characterized by relatively small values of the electron-phonon coupling constant lambda, which can thus be further increased by hole doping before lattice instabilities occur. In particular we show that T-c larger than 100 K are compatible in the nonadiabatic context with microscopic parameters lambda(h)similar or equal to0.5-1.0, mu(*)similar or equal to0.3-0.5 and phonon frequencies omega(ph)similar or equal to1500-2000 K. These results provide a stimulus for material engineering and optimization along the lines indicated

Civil structures made entirely from FRP pultruded beams

The aim of this paper is to present the main problems connected to the design of a civil structures made from composite materials, starting from the initial choice of the material up to the choice of the opportune procedure for designing and verifying the FRP elements. Finally, the authors carried out an example of rehabilitation of a roofing structure consisting in replace totally the latter with a new one made entirely from FRP pultruded profiles. The new roofing structure is truss-frame type with a length equal to twelve meter whose connections are realized with steel bolts. The material used consist of glass FRP and the geometrical and mechanical properties are given by technical data sheets edited by the manufacturer

Obstructing left sided colorectal cancer. A retrospective single center study.

Background: In recent years, with population aging, there has been an increased number of colorectal cancer cases in elderly patients with severe occlusion symptoms. About 75% of obstructions due to malignant colorectal cancer (10-30%) occur distal to splenic flexure. Methods: The authors evaluated the best surgical therapeutic strategy to be used in cases of left-sided colorectal carcinoma in patients over 65 years old, especially considering the emergency condition, age of patients and efficacy in terms of postoperative morbidity, mortality and 5 years survival rate. Results: The management of left-sided obstructing colorectal carcinoma is controversial. Hartmann’s procedure is the best therapeutic choice in elderly patients. However, resection with intraoperative colonic wash-out and primary anastomosis has favorable outcome in low risk patients. Conclusions: A review of the literature reveals that primary resection and anastomosis for left-sided obstructing CRC is the correct therapeutic strategy in low risk patients with localized, resectable carcinoma, without peritonitis; Hartmann’s procedure should be adopted in doubtful cases and in high risk patients

Surgical mistake causing an high recto-vaginal fistula. A case report with combined surgical and endoscopic approach: therapeutic considerations

BACKGROUND: Rectovaginal fistulas (RVFs) have multiple causes, size and location on which the surgical treatment depends. DESCRIPTION: The Authors consider different approaches to RVFs and describe a clinical case of recurrent high RVF. CONCLUSIONS: Most RVFs can be successfully repaired, although many interventions may be necessary. A colostomy with delayed repair may improve RVFs outcome. Moreover, several authors indicate Mucosal Advancement Flap and Babcock-Bacon technique as the treatments of choice respectively for low and high RVFs (complex and recurrent) and emphasize the placement of endoscopic prothesis in cases of difficult healing of the anastomosis

Poor screening and nonadiabatic superconductivity in correlated systems

In this paper we investigate the role of the electronic correlation on the hole doping dependence of electron-phonon and superconducting properties of cuprates. We introduce a simple analytical expression for the one-particle Green's function in the presence of electronic correlation and we evaluate the reduction of the screening properties as the electronic correlation increases by approaching half-filling. The poor screening properties play an important role within the context of the nonadiabatic theory of superconductivity. We show that a consistent inclusion of the reduced screening properties in the nonadiabatic theory can account in a natural way for the $T_c$-$\delta$ phase diagram of cuprates. Experimental evidences are also discussed.Comment: 12 Pages, 6 Figures, Accepted on Physical Review

Evaluating spintronics-compatible implementations of Ising machines

The commercial and industrial demand for the solution of hard combinatorial optimization problems push forward the development of efficient solvers. One of them is the Ising machine which can solve combinatorial problems mapped to Ising Hamiltonians. In particular, spintronic hardware implementations of Ising machines can be very efficient in terms of area and performance, and are relatively low-cost considering the potential to create hybrid CMOS-spintronic technology. Here, we perform a comparison of coherent and probabilistic paradigms of Ising machines on several hard Max-Cut instances, analyzing their scalability and performance at software level. We show that probabilistic Ising machines outperform coherent Ising machines in terms of the number of iterations required to achieve the problem s solution. Nevertheless, high frequency spintronic oscillators with sub-nanosecond synchronization times could be very promising as ultrafast Ising machines. In addition, considering that a coherent Ising machine acts better for Max-Cut problems because of the absence of the linear term in the Ising Hamiltonian, we introduce a procedure to encode Max-3SAT to Max-Cut. We foresee potential synergic interplays between the two paradigms.Comment: 26 pages, 6 Figures, submitted for publication in Phys. Rev. Applied (it will be presented at intermag 2023 in Japan

Fontana Ranuccio (excavations 2019-2022) and Colle Marino (excavations 2020-2021): Middle Pleistocene chronostratigraphic evidence of the earliest inhabitants in the Anagni basin

Recent fieldwork of the Istituto Italiano di Paleontologia Umana in the Anagni basin (Latin Valley, southern Latium, central Italy) has provided new insights into the dynamics of human settlement and adaptation in this area during the Middle Pleistocene. This paper summarizes the still partially unpublished data on the chronostratigraphy of two important prehistoric sites: Fontana Ranuccio, dating from about 400,000 years ago, and Colle Marino, whose lithic industry has so far been attributed to an early stage of the Middle Pleistocene. At Fontana Ranuccio, stratigraphic studies highlighted the depositional dynamics and the processes involved in the formation of the archeological unit, consisting of partly reworked volcanic material, which can be now divided into distinct sub-units. At Colle Marino, a 35-meter-deep core drilling and an excavation campaign allowed us to verify the nature and provenance of lithic artifacts found on the surface in past decades. Radiometric analyses dated these artifacts from about 700,000 years ago