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On April 2020, during the outburst of the COVID-19 pandemic in Italy, the SIAARTI (“Società Italiana di Anestesia, Analgesia, Rianimazione e Terapia Intensiva”) Research Group on Vascular Access has formulated some essential recommendations for the optimization of the selection, insertion, and maintenance of the vascular access devices, with the aim of guarantee the operator safety, ensure the effectiveness of the maneuvers, and reduce the risk of complications. Here we describe the key elements of clinical management of vascular access in patients affected by COVID-19.

Numerical prediction of the heat transfer to low-Prandtl-number fluids has been carried out. A one-equation (k) turbulence model in the near-wall region and a two-equation (k ∼ e) turbulence model In the core region are employed. Many expressions proposed in the literature for the Prt numbers are examined. The fully developed temperature profiles obtained are compared with experimental results In the ranges Pr = 0.019-0.029 and Re = 40,000-400,000. The following Prt relations are finally recommended: the Aoki and Reynolds expressions in the range Re = 40,000-170,000 and the relation proposed by Jischa and Rieke for Re = 170,000-260,000. The Nusselt number results are compared with the experimental data In the literature and the agreement is good.

Numerical prediction of the heat transfer to low-Prandtl-number fluids has been carried out. A one-equation (k) turbulence model in the near-wall region and a two-equation (k ∼ e) turbulence model in the core region are employed. Many expressions proposed in the literature for the Prt numbers are examined. The fully developed temperature profiles obtained are compared with experimental results in the ranges Pr = 0.019-0.029 and Re = 40,000-400,000. The following Prt relations are finally recommended: the Aoki and Reynolds expressions in the range Re = 40,000-170,000 and the relation proposed by Jischa and Rieke for Re = 170,000-260,000. The Nusselt number results are compared with the experimental data in the literature and the agreement is good.

The isobaric thermal expansion coefficient ( 0) was determined experimentally as a function of temperature for two non-Newtonian fluids: water solutions of CMC 7H4 at 5000 parts per million by weight (wppm) (purely viscous fluid) and AP-273 Separan at 2000 wppm (viscoelastic fluid). The temperature range was approximately 25-55° c theological flow curves were also measured during the experimental sequence. The expansion coefficients for the non-Newtonian fluids agreed with those for the pure water solvent within the experimental accuracy (± 1% ) whereas the theological properties showed significant changes due, it is thought, to the thermal cycling and aging effects.

The energy equation for mechanically fully developed turbulent flow between parallel plates is numerically solved taking into account the term of streamwise heat conduction. Solutions are presented for Re = 7060 and 73620, and for Pr ranging from 0.001 to 0.1. Generally the influence of the streamwise molecular conduction results in a remarkable decrease of the Nusselt number in the thermal inlet.

A theoretical investigation of the combined influence of natural convection and consistency variations in laminar heating of non-Newtonian fluids has been carried out. The heating of a power law fluid with an initially fully developed velocity profile flowing upward through a vertical tube with a constant wall heat flux was considered. The system of governing equations, complete with the convective terms, was solved numerically. Detailed comparisons with previous theoretical and experimental results were performed to check the integrity of the solutions obtained with the present approach. Local heat transfer coefficients, as a function of Graetz number, were presented. Local heat transfer results showed that for pseudoplastic fluids with smaller Prandtl number the parameter Pr was very important in the inlet and in the intermediate part of the tube.

Unsteady and steady flow in a cylindrical chamber with a rotating cover has been studied for two Reynolds numbers and three aspect ratio values. The structure of the velocity and pressure fields in the apparatus is described. Primary and secondary volumetric flow rates and torque coefficients are also calculated for all six cases solved.

Herpes Zoster (HZ) is the reactivation of a well-known viral disease which manifests itself with painful skin lesions. An effective analgesic method during the acute phase of HZ can contribute to decrease the incidence of postherpetic neuralgia (PHN) by reducing neural sensitization. Sciatic nerve block (SNB) is useful in the management of distal lower extremity pain sustained by the sciatic nerve. We describe our experience with a continuous ultrasound guided subgluteus sciatic nerve block in a patient with herpetic neuralgia- (HN-) related refractory acute left leg pain.