Search results for " heat"
showing 10 items of 830 documents
Empirical molecular dynamics study of structural, elastic and thermodynamic properties of zinc-blende-like SiGe compound
2004
Abstract A three-body potential coupled with a molecular-dynamics method is used to calculate structural and thermodynamic properties of the hypothetical IV–IV compound SiGe in zinc-blende phase. A good agreement between the calculated and theoretical values of the lattice constant, the bulk modulus and its derivative, and the cohesive energy is obtained. We also compute the elastic constants, Debye temperature, lattice thermal expansion, and the specific heat. We investigate also, the structural properties of SiGe when rock-salt phase appears.
Fluid geochemistry in a low-enthalpy geothermal field along a sector of southern Apennines chain (Italy)
2020
Abstract The chemical and isotopic features of the fluids (water and gases) in the Lucane thermal area (southern Italy) have been investigated in order to verify their origin, water temperature in the geothermal reservoir, and to recognize the main natural processes concerning the water composition during ascent towards the surface. The Lucane geothermal system is placed in the southern sector of the Apennines chains, a seismically active area, close to the southern base of the Mt. Alpi carbonate massif. Along the study area, two main sets of high-angle faults form an almost orthogonal fault system that, as suggested by local structural geology, acts as a preferential pathway for uprising d…
Inhibition of HSP70: a challenging anti-cancer strategy.
2012
HSP70 is a chaperone that accumulates in the cells after many different stresses promoting cell survival in response to the adverse conditions. In contrast to normal cells, most cancer cells abundantly express HSP70 at the basal level to resist to various insults at different stages of tumorigenesis and during anti-cancer treatment. This cancer cells addiction for HSP70 is the rational for its targeting in cancer therapy. Much effort has been dedicated in the last years for the active search of HSP70 inhibitors. Additionally, the recent clinical trials on highly promising inhibitors of another stress protein, HSP90, showed compensatory increase in HSP70 levels and raised the question of nec…
Nanofitins targeting heat shock protein 110: an innovative immunotherapeutic modality in cancer.
2021
The presence of an inactivating heat shock protein 110 (HSP110) mutation in colorectal cancers has been correlated with an excellent prognosis and with the ability of HSP110 to favor the formation of tolerogenic (M2-like) macrophages. These clinical and experimental results suggest a potentially powerful new strategy against colorectal cancer: the inhibition of HSP110. In this work, as an alternative to neutralizing antibodies, Nanofitins (scaffold ~7 kDa proteins) targeting HSP110 were isolated from the screening of a synthetic Nanofitin library, and their capacity to bind (immunoprecipitation, biolayer interferometry) and to inhibit HSP110 was analyzed in vitro and in vivo. Three Nanofiti…
Hsp72 controls bortezomib-induced HepG2 cell death via interaction with pro-apoptotic factors.
2007
The proteasome inhibitor bortezomib is an efficacious inducer of apoptosis in the hepatoma HepG2 cell line. This study shows that bortezomib increased in these cells the level of the survival factor Hsp72 in a time- and dose-dependent manner. In a first phase of treatment, Hsp72 rapidly increased so that at 24 h of incubation with 50 nM bortezomib its level was approximately five-fold higher than the control. In this phase Hsp72 seemed to play a role in preventing HepG2 cell death, since it interacted with and sequestered the pro-apoptotic factors p53, AIF, Bax and Apaf-1. During a second day of treatment, although the nuclear levels of Hsp72, p53 and AIF increased, the interaction of Hsp72…
Oligodendroglioma cells shed microvesicles which contain TRAIL as well as molecular chaperones and induce cell death in astrocytes.
2011
Microvesicles (MVs) shed from G26/24 oligodendroglioma cells were previously reported to cause a reproducible, dose-dependent, inhibitory effect on neurite outgrowth, and eventually neuronal apoptosis, when added to primary cultures of rat cortical neurons. These effects were reduced but not abolished by functional monoclonal antibodies against Fas-L. In order to investigate whether MVs contain other factors able to induce cell death, we tested them for TRAIL and found clear evidence of its presence in the vesicles. This finding suggests the possibility that Fas-L and TRAIL cooperate in inducing brain cell death. Aimed at understanding the route through which the vesicles deliver their mess…
Oncolytic parvovirus H1 induces release of heat-shock protein HSP72 in susceptible human tumor cells but may not affect primary immune cells.
2003
Certain autonomous parvoviruses preferentially replicate in and kill in vitro-transformed cells and may reduce the incidence of spontaneous and implanted tumors in animals. Hence, these viruses and their derivatives are currently under evaluation as antitumor vectors. However, the mechanisms underlying their tumor-suppressing properties are not yet understood. We asked whether the lytic parvovirus H1 may enhance the immunogenicity of infected tumor cells. Out of human melanoma and gastrointestinal tumor cells, we selected the cell line SK29-Mel-1 being very susceptible to H1-induced apoptotic killing. Here, no upregulation of HLA class I and costimulatory molecules could be observed followi…
Molecular Approaches to Target Heat Shock Proteins for Cancer Treatment
2015
HSP90 was the first molecular target to inhibit the interaction of this heat shock protein (HSP) with client proteins in cancer cells and tissues. The HSP90 inhibition was attempted to liberate from this chaperone the oncogenic fusion proteins, mutated and activated serine/threonine protein kinases, tyrosine kinases, as well as transcription factors with oncogenic activity, in this manner, the free proteins could be recognized by the proteasome system to be degraded. We should remember here that many HSP family members are overexpressed in different kinds of cancer tissues, these molecules act as chaperones of tumorigenesis. In cancer patients, the first generation of HSP90 inhibitors showe…
Basic Notions of the Theory of Heat
2016
This chapter summarizes some basic notions of thermodynamics and defines the empirical variables which are needed for the description of thermodynamic systems in equilibrium. Empirical temperature and several scales used to measure temperature are defined. The so-called “zeroth law of thermodynamics” is formulated which says that systems which are in mutual equilibrium have the same temperature. Thermodynamic ensembles corresponding to different macroscopic boundary conditions are introduced and are illustrated by simple models such as the ideal gas. Also, entropy appears on the scene for a first time, both in its statistical and its thermodynamical interpretation. Gibb’s fundamental form i…
On the Use of the Eddy Covariance Latent Heat Flux and Sap Flow Transpiration for the Validation of a Surface Energy Balance Model
2018
Actual evapotranspiration is assessed via surface energy balance at an hourly rate. However, a robust estimation of daily evapotranspiration from hourly values is required. Outcomes of surface energy balance are frequently determined via measures of eddy covariance latent heat flux. Surface energy balance can be applied on images acquired at different times and spatial resolutions. In addition, hourly actual evapotranspiration needs to be integrated at a daily rate for operational uses. Questions arise whether the validation of surface energy balance models can benefit from complementary in situ measures of latent heat flux and sap flow transpiration. Here, validation was driven by image ac…