Hyaluronan is a natural and effective immunological adjuvant for protein-based vaccines

One of the main goals of vaccine research is the development of adjuvants that can enhance immune responses and are both safe and biocompatible. We explored the application of the natural polymer hyaluronan (HA) as a promising immunological adjuvant for protein-based vaccines. Chemical conjugation of HA to antigens strongly increased their immunogenicity, reduced booster requirements, and allowed antigen dose sparing. HA-based bioconjugates stimulated robust and long-lasting humoral responses without the addition of other immunostimulatory compounds and proved highly efficient when compared to other adjuvants. Due to its intrinsic biocompatibility, HA allowed the exploitation of different injection routes and did not induce inflammation at the inoculation site. This polymer promoted rapid translocation of the antigen to draining lymph nodes, thus facilitating encounters with antigen-presenting cells. Overall, HA can be regarded as an effective and biocompatible adjuvant to be exploited for the design of a wide variety of vaccines

First Italian TRT database and significance of the geological setting evaluation in borehole heat exchanger sizing

The correct sizing of the borehole field in closed-loop Ground Source Heat Pump (GSHP) systems requires accurate value of the ground thermal properties, especially the thermal conductivity. One of two methods are generally applied to evaluate this parameter: the Thermal Response Test (TRT) and databases reported in guidelines or Standards for lithologies identified in the local stratigraphy. This paper presents a database of more than 100 Thermal Response Tests performed in Italy. The equivalent thermal conductivities derived from the TRT outputs are here directly compared with the value estimated through knowledge of the local geological stratigraphy. The obtained results are analyzed in terms of geological setting. A sensitivity analysis on the borefield design has been conducted to evaluate the effects of the equivalent thermal conductivity estimation error on the calculation of the required total borehole length. The borehole length, in turn, strongly affects the initial investment costs as well as the operating conditions of the heat pump over the long term. The obtained results, in some cases significant, highlight the importance of performing the TRT not only when the thermal capacity of the GSHP is high but also in the case of strong geological uncertainty, or in particular geological settings such as high plain areas, alpine valley floors and rocky environments. In the other cases as low plain areas, this database can provide an initial estimate of the range of the expected equivalent thermal conductivity value; therefore, it can be useful for designers of both GSHP systems and other applications where the knowledge of the underground thermal behavior is necessary

Geotechnical Hazards Caused by Freezing-Thawing Processes Induced by Borehole Heat Exchangers

In closed-loop Ground Source Heat Pump system (GSHP), the thermal exchange with the underground is provided by a heat-carrier fluid circulating into the probes. In order to improve the heat extraction rate during winter, the heat-carrier fluid temperature is often lowered down to 125 \ub0C; this way, the induced thermal anomaly is more intense and can cause freezing processes in the surrounding ground. In sediments with significant clay fraction, the inner structure and the porosity distribution are irreversibly altered by freezing-thawing cycles; therefore, the geotechnical properties (such as deformability, stiffness and permeability) are significantly affected. A wide laboratory program has been performed in order to measure the induced deformations and the permeability variations under different conditions of thermal and mechanical loads and interstitial water salinity. The results suggest that, despite the induced frozen condition is quite confined close to the borehole, the compaction induced in cohesive layers is significant and irreversible and could generate negative friction on the borehole heat exchanger; in addition, the permeability increase in the probe surroundings could lead interconnection among aquifers, with increasing effects with the number of boreholes in the borefield

Influence of recycled tyre amendment on the mechanical behaviour of soil-bentonite cut-off walls

© 2017 Elsevier Ltd. Generation of the scarp tyre has increased in recent years, and finding innovative reusing methods is of interest to researchers. This study aims to investigate the hydraulic conductivity and one-dimensional consolidation behaviour of soil-bentonite (SB) backfill amended with powdered recycled tyre (PRT) and crumbed recycled tyre (CRT) by performing a series of oedometer consolidation and rigid-wall hydraulic conductivity tests. Three values of PRT and CRT (i.e., 2%, 5% and 10% by dry weight) were used to prepare the specimens. The investigation on vertical strain-time graphs showed that the addition of PRT and CRT caused an increase in settlement characteristics of the SB backfill. The results also showed that the addition of PRT and CRT caused an increase in the compression index (C i ) and the swelling index (C s ) of the SB specimens. The coefficient of consolidation (c v ) based on the Casagrande and Taylor methods showed a consistent increasing trend by increasing the PRT and CRT. The hydraulic conductivity was computed based on the Terzaghi consolidation theory (k theory ), and the results showed that increasing the PRT and CRT caused an increase in hydraulic conductivity of the SB backfill. The hydraulic conductivity (k f ) measured using a rigid-wall permeability compaction mould showed a similar increasing trend by increasing the PRT and CRT contents of the backfills

Repeated ETRTs in a Complex Stratified Geological Setting: High-Resolution Thermal Conductivity Identification by Multiple Linear Regression

For the design of ground-source heat-pump systems, the local subsoil is an invariant factor. To improve the evaluation of the local heat exchange capability, significant efforts recently have been devoted to identifying the ground thermal conductivity vertical profile. In recent years, an innovative method using hybrid optic fiber cables inserted into the ground has been developed. The technique relies on copper wires that thermally stimulate the ground. Optical fibers measure the temperature variation over time all along the cable at a high spatial and temporal resolution. In this work, the hybrid cable was grouted into a 125-m well located in the Po Plain in Northern Italy. The provided core defined the geological environment as a continuous succession of unconsolidated alluvial deposits of very limited thickness, grouped in 15 different granulometric units. Three enhanced thermal response test (ETRT) data sets were acquired in different seasons; for 5 days of heating followed by 5 days of recovery, the soil temperature was recorded continuously along the well, with a spatial resolution of 1 m. A new approach using a multiple linear regression is proposed to analyze the data sets to distinguish the thermal conductivity of each individual granulometric unit. The obtained thermal conductivity values were compared and discussed considering the standard thermal response test outputs and the thermal conductivity data obtained from direct measurements performed on the cores. The analytical method's reliability stands due to the high repeatability of the obtained results, despite the increased complexity of the treated geological setting

A large number of T lymphocytes recognize Moloney-murine leukemia virus-induced antigens, but a few mediate long-lasting tumor immunosurveillance

The CD8(+) T cell response to Moloney-murine leukemia virus (M-MuLV)-induced Ags is almost entirely dominated by the exclusive expansion of lymphocytes that use preferential TCRVbeta chain rearrangements. In mice lacking T cells expressing these TCRVbeta, we demonstrate that alternative TCRVbeta can substitute for the lack of the dominant TCRVbeta in the H-2-restricted M-MuLV Ag recognition. We show that, at least for the H-2(b)-restricted response, the shift of TCR usage is not related to a variation of the immunodominant M-MuLV epitope recognition. After virus immunization, all the potentially M-MuLV-reactive lymphocytes are primed, but only the deletion of dominant Vbeta rescues the alternative Vbeta response. The mechanism of clonal T cell "immunodomination" that guides the preferential Vbeta expansion is likely the result of a proliferative advantage of T cells expressing dominant Vbeta, due to differences in TCR affinity and/or cosignal requirements. In this regard, a CD8 involvement is strictly required for the virus-specific cytotoxic activity of CTL expressing alternative, but not dominant, Vbeta gene rearrangements. The ability of T cells expressing alternative TCRVbeta rearrangements to mediate tumor protection was evaluated by a challenge with M-MuLV tumor cells. Although T cells expressing alternative Vbeta chains were activated and expanded, they were not able to control tumor growth in a long-lasting manner due to their incapacity of conversion and accumulation in the T central memory pool