Noise thermometry applied to thermoelectric measurements in InAs nanowires

We apply noise thermometry to characterize charge and thermoelectric transport in single InAs nanowires (NWs) at a bath temperature of 4.2 K. Shot noise measurements identify elastic diffusive transport in our NWs with negligible electron-phonon interaction. This enables us to set up a measurement of the diffusion thermopower. Unlike in previous approaches, we make use of a primary electronic noise thermometry to calibrate a thermal bias across the NW. In particular, this enables us to apply a contact heating scheme, which is much more efficient in creating the thermal bias as compared to conventional substrate heating. The measured thermoelectric Seebeck coefficient exhibits strong mesoscopic fluctuations in dependence on the back-gate voltage that is used to tune the NW carrier density. We analyze the transport and thermoelectric data in terms of approximate Mott's thermopower relation and to evaluate a gate-voltage to Fermi energy conversion factor

Local noise in a diffusive conductor

The control and measurement of local non-equilibrium configurations is of utmost importance in applications on energy harvesting, thermoelectrics and heat management in nano-electronics. This challenging task can be achieved with the help of various local probes, prominent examples including superconducting or quantum dot based tunnel junctions, classical and quantum resistors, and Raman thermography. Beyond time-averaged properties, valuable information can also be gained from spontaneous fluctuations of current (noise). From these perspective, however, a fundamental constraint is set by current conservation, which makes noise a characteristic of the whole conductor, rather than some part of it. Here we demonstrate how to remove this obstacle and pick up a local noise temperature of a current biased diffusive conductor with the help of a miniature noise probe. This approach is virtually noninvasive and extends primary local measurements towards strongly non-equilibrium regimes.Comment: minor revision, accepted in Scientific Report

A procedure for designing natural water retention measures in new development areas under hydraulic-hydrologic invariance constraints

In recent years, in Italy and elsewhere, regional regulations based on hydraulic-hydrologic invariance (HHI) principles have taken hold, especially for new development areas. Natural water retention measures (NWRMs) are among the most interesting options to provide the storage and infiltration capacities that are needed to achieve the HHI objectives. A procedure for the design of NWRMs in new development areas under HHI constraints is presented and is based on a simple combination of Soil Conservation Service Curve Number (SCS-CN) method for determining rainfall excess and lag-time method for simulating runoff propagation. Three types of NWRMs can be considered: rain barrels, drainage wells and drainage trenches; five types of synthetic hyetographs can be selected and three different approaches for the determination of critical storm duration applied. The results obtained by applying the procedure in a new development area located in northern Italy are illustrated and some general conclusions are drawn. It clearly emerges that practitioners should pay particular attention to the correct determination of design storm duration in order to avoid large underestimations of NWRMs size. Moreover, different combinations of the three NWRMs can provide the required reduction of peak of runoff after the transformation, but it appears that drainage trenches are more effective with respect to harvesting systems in reducing the peak runoff value

Thermo-programmed synthetic DNA-based receptors

Herein, we present a generalizable and versatile strategy to engineer synthetic DNA ligand-binding devices that can be programmed to load and release a specific ligand at a defined temperature. We do so by re-engineering two model DNA-based receptors: a triplex-forming bivalent DNA-based receptor that recognizes a specific DNA sequence and an ATP-binding aptamer. The temperature at which these receptors load/release their ligands can be finely modulated by controlling the entropy associated with the linker connecting the two ligand-binding domains. The availability of a set of receptors with tunable and reversible temperature dependence allows achieving complex load/release behavior such as sustained ligand release over a wide temperature range. Similar programmable thermo-responsive synthetic ligand-binding devices can be of utility in applications such as drug delivery and production of smart materials

TERREMOTI NELL’OMBRA: UN EVENTO CALABRESE NASCOSTO DAL GRANDE TERREMOTO DEL 1915

L’occorrenza di un terremoto distruttivo ha numerose implicazioni, sia di tipo fisico (modifica del campo di stress tettonico) che di tipo storico culturale. Nella storia sismica italiana l’occorrenza di forti terremoti ha generato spesso un aumento dell’attenzione verso questo fenomeno, ed è direttamente correlabile con alcune iniziative che hanno costituito la stessa tradizione storico-sismologica italiana, quali - ad esempio - la redazioni di importanti compilazioni sismologiche, (Giannozzo Manetti e Marcello Bonito, rispettivamente dopo i terremoti del 1456 e del 1688), o la nascita del servizio geodinamico italiano (all’indomani del terremoto ligure del 1887). Tuttavia i terremoti distruttivi hanno anche un effetto di ‘oscuramento’ nella tradizione storica di eventi meno forti, prossimi nello spazio (ma non necessariamente) e soprattutto nel tempo. Diversi casi storici sono stati segnalati da lavori recenti (Camassi e Castelli, 2005), e molti altri sono probabilmente ancora da ‘scoprire’. Nel presente lavoro si illustra un caso di questo genere, che ha la particolarità di verificarsi in tempi molto recenti, immediatamente a ridosso del grande terremoto della Marsica del 1915. Il terremoto colpisce la Calabria Settentrionale, a nord-ovest di Cosenza, e pur non modificando in modo significativo il quadro di conoscenze sulla sismicità dell’area, relativamente ‘ricco’, rappresenta comunque un caso significativo e uno spunto di riflessione importante sul tema della completezza storica delle informazioni sismologiche

Robotic versus laparoscopic left colectomy: a systematic review and meta-analysis

Background: This study aimed to review the new evidence to understand whether the robotic approach could find some clear indication also in left colectomy. Methods: A systematic review of studies published from 2004 to 2022 in the Web of Science, PubMed, and Scopus databases and comparing laparoscopic (LLC) and robotic left colectomy (RLC) was performed. All comparative studies evaluating robotic left colectomy (RLC) versus laparoscopic (LLC) left colectomy with at least 20 patients in the robotic arm were included. Abstract, editorials, and reviews were excluded. The Newcastle–Ottawa Scale for cohort studies was used to assess the methodological quality. The random-effect model was used to calculate pooled effect estimates. Results: Among the 139 articles identified, 11 were eligible, with a total of 52,589 patients (RLC, n = 13,506 versus LLC, n = 39,083). The rate of conversion to open surgery was lower for robotic procedures (RR 0.5, 0.5–0.6; p < 0.001). Operative time was longer for the robotic procedures in the pooled analysis (WMD 39.1, 17.3–60.9, p = 0.002). Overall complications (RR 0.9, 0.8–0.9, p < 0.001), anastomotic leaks (RR 0.7, 0.7–0.8; p < 0.001), and superficial wound infection (RR 3.1, 2.8–3.4; p < 0.001) were less common after RLC. There were no significant differences in mortality (RR 1.1; 0.8–1.6, p = 0.124). There were no differences between RLC and LLC with regards to postoperative variables in the subgroup analysis on malignancies. Conclusions: Robotic left colectomy requires less conversion to open surgery than the standard laparoscopic approach. Postoperative morbidity rates seemed to be lower during RLC, but this was not confirmed in the procedures performed for malignancies