Isothermal Calorimetry

2021 ◽  
pp. 135-159
Author(s):  
Christopher M. Johnson
Keyword(s):  
Isothermal Calorimetry

Antigene and Antiproliferative Effects of Triplex-Forming Oligonucleotide (TFO) Targeted on hmgb1 Gene in Human Hepatoma Cells

2020 ◽  
Vol 20 (16) ◽  
pp. 1943-1955
Author(s):  
Neelam Lohani ◽  
Moganty R. Rajeswari
Keyword(s):  
Apoptotic Cell ◽  
Isothermal Calorimetry ◽  
High Mobility ◽  
Rational Drug Design ◽  
Human Hepatoma Cells ◽  
Aberrant Expression ◽  
Bioinformatic Tools ◽  
Hmgb1 Expression ◽  
Dna Triplex ◽  
Triplex Forming Oligonucleotide

Background: The high mobility group box 1 (hmgb1) is one of the frequently over-expressed genes whose aberrant expression is reported in a number of human cancers. Various strategies are underway to inhibit hmgb1 expression in cancer cells having considerable therapeutic value. Objective: The present work involves selective transcriptional inhibition of the hmgb1 gene using selective DNA triplex structure-based gene technology. Here, the promoter region of the hmgb1 gene at position (-183 to -165) from the transcription start site as a target was selected using bioinformatic tools. Methods: The DNA triplex formation by the DNA of the target gene and TFO was confirmed using UV absorption spectroscopy, Circular Dichroism, and Isothermal Calorimetry. Results: Treatment of HepG2 cell with specific Triplex-forming Oligonucleotide significantly downregulated HMGB1 expression level at mRNA and protein levels by 50%, while the classical anticancer drugs, actinomycin/ adriamycin as positive controls showed 65% and the combination of TFO and drug decreased by 70%. The anti-proliferative effects of TFO correlated well with the fact of accumulation of cells in the Go phase and apoptotic cell death. Further, the binding of anti-cancer drugs to hmgb1 is stronger in DNA triplex state as compared to hmgb1 alone, suggesting the combination therapy as a better option. Conclusion: Therefore, the ability of hmgb1 targeted triplex-forming oligonucleotide in combination with triplex selective anticancer drug holds promise in the treatment of malignancies associated with hmgb1 overexpression. The result obtained may open up new vistas to provide a basis for the rational drug design and searching for high-affinity ligands with a high triplex selectivity.

scholarly journals Long-term cement hydration studies with isothermal calorimetry

2021 ◽  
Vol 141 ◽  
pp. 106344
Author(s):  
O. Linderoth ◽  
L. Wadsö ◽  
D. Jansen
Keyword(s):  
Cement Hydration ◽  
Isothermal Calorimetry

scholarly journals The role of graphene/graphene oxide in cement hydration

2021 ◽  
Vol 10 (1) ◽  
pp. 768-778
Author(s):  
Shaoqiang Meng ◽  
Xiaowei Ouyang ◽  
Jiyang Fu ◽  
Yanfei Niu ◽  
Yuwei Ma
Keyword(s):  
Graphene Oxide ◽  
Cement Paste ◽  
Cement Hydration ◽  
Isothermal Calorimetry ◽  
High Mobility ◽  
Nucleation And Growth ◽  
Early Hydration ◽  
Mobility Of Ions ◽  
Cement Surface

Abstract Graphene (G) and graphene oxide (GO) have been shown to significantly improve the mechanical properties of cement-based materials. In this study, the effect of the G/GO on cement hydration was investigated. First, the zeta potential of G/GO in simulated solutions was tested, and the interaction between G/GO’s surface and Ca2+ was explored. Subsequently, scanning electron microscopy was used to observe the morphology of C–S–H nucleation and growth on the cement surface in the cement paste containing G/GO. Furthermore, XRD and TGA analyses were carried out on the hydration products of the sample. At last, isothermal calorimetry was applied to investigate the influence of G/GO on the early hydration of cement. The results showed that the addition of G/GO significantly accelerates C–S–H nucleation and growth on the cement surface. It is indicated that the high mobility ions derived by G/GO in the cement paste dominate the reason for the accelerated hydration of cement. The presence of G, especially GO, facilitates the mobility of ions, especially Ca2+, thus enhances the interaction between the cement surface and the ions. This strong interaction promotes the C–S–H nucleation and growth, and therefore, the hydration of the cement.

Study on Calorimetry of Excess Heat in a d/Pd Gas-Loading System

2021 ◽  
Vol 881 ◽  
pp. 51-56
Author(s):  
Xing Ye Wang ◽  
Bing Jun Shen ◽  
Li Hong Jin ◽  
Ling Yu Li ◽  
Jian Tian
Keyword(s):  
Heat Flow ◽  
Isothermal Calorimetry ◽  
Electrical Current ◽  
Input Power ◽  
Heat Power ◽  
Experimental Conditions ◽  
Excess Heat ◽  
Flow Calorimeter ◽  
Loading System ◽  
Deuterium Pressure

A heat-flow calorimeter was introduced into the D/Pd gas-loading system to confirm the reliability and accuracy of the results obtained by isothermal calorimetry in the previous work. The effects of input power (electrical current) and pressure on excess heat were discussed under different experimental conditions. The results showed that the heat-flow calorimetry had higher accuracy than isothermal calorimetry. Under deuterium pressure of 30 kPa, the excess heat power decreased with the decrease of the input power, and the maximum excess heat power was (6.40 ± 0.19) W with an input power of 380 W. In the experiments of discussing the relationship between pressure and excess heat, the results showed there was a maximum excess power of (10.28 ± 3.40) W when the deuterium pressure was 220 Pa. The excess heat measured in the system was far more than that in chemical reaction. The results of SEM and EDS implied that excess heat came from nuclear transmutation processes.

New Long-Life Concrete Pavements in the Czech Republic

2021 ◽  
Author(s):  
Bohuslav Slánský ◽  
Vit Šmilauer ◽  
Jiří Hlavatý ◽  
Richard Dvořák
Keyword(s):  
Isothermal Calorimetry ◽  
Coupled Model ◽  
Plain Concrete ◽  
Pilot Project ◽  
Economic Benefits ◽  
Concrete Pavement ◽  
Technical Solution ◽  
Concrete Pavements ◽  
Hydration Kinetics

A jointed plain concrete pavement represents a reliable, historically proven technical solution for highly loaded roads, highways, airports and other industrial surfaces. Excellent resistance to permanent deformations (rutting) and also durability and maintenance costs play key roles in assessing the economic benefits, rehabilitation plans, traffic closures, consumption and recycling of materials. In the history of concrete pavement construction, slow-to-normal hardening Portland cement was used in Czechoslovakia during the 1970s-1980s. The pavements are being replaced after 40-50 years of service, mostly due to vertical slab displacements due to missing dowel bars. However, pavements built after 1996 used rapid hardening cements, resulting in long-term surface cracking and decreased durability. In order to build durable concrete pavements, slower hardening slag-blended binders were designed and tested in the restrained ring shrinkage test and in isothermal calorimetry. Corresponding concretes were tested mainly for the compressive/tensile strength evolution and deicing salt-frost scaling to meet current specifications. The pilot project was executed on a 14 km highway, where a unique temperature-strain monitoring system was installed to provide long-term data from the concrete pavement. A thermo-mechanical coupled model served for data validation, showing a beneficial role of slower hydration kinetics. Continuous monitoring interim results at 24 months have revealed small curling induced by drying and the overall small differential shrinkage of the slab.

scholarly journals Revisiting the Effect of Slag in Reducing Heat of Hydration in Concrete in Comparison to Other Supplementary Cementitious Materials

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1847 ◽  
Author(s):  
Hoon Moon ◽  
Sivakumar Ramanathan ◽  
Prannoy Suraneni ◽  
Chang-Seon Shon ◽  
Chang-Joon Lee ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Temperature Rise ◽  
Adiabatic Calorimetry ◽  
Blast Furnace Slag ◽  
Isothermal Calorimetry ◽  
Heat Of Hydration ◽  
Supplementary Cementitious Materials ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Furnace Slag

Blast furnace slag (SL) is an amorphous calcium aluminosilicate material that exhibits both pozzolanic and latent hydraulic activities. It has been successfully used to reduce the heat of hydration in mass concrete. However, SL currently available in the market generally experiences pre-treatment to increase its reactivity to be closer to that of portland cement. Therefore, using such pre-treated SL may not be applicable for reducing the heat of hydration in mass concrete. In this work, the adiabatic and semi-adiabatic temperature rise of concretes with 20% and 40% SL (mass replacement of cement) containing calcium sulfate were investigated. Isothermal calorimetry and thermal analysis (TGA) were used to study the hydration kinetics of cement paste at 23 and 50 °C. Results were compared with those with control cement and 20% replacements of silica fume, fly ash, and metakaolin. Results obtained from adiabatic calorimetry and isothermal calorimetry testing showed that the concrete with SL had somewhat higher maximum temperature rise and heat release compared to other materials, regardless of SL replacement levels. However, there was a delay in time to reach maximum temperature with increasing SL replacement level. At 50 °C, a significant acceleration was observed for SL, which is more likely related to the pozzolanic reaction than the hydraulic reaction. Semi-adiabatic calorimetry did not show a greater temperature rise for the SL compared to other materials; the differences in results between semi-adiabatic and adiabatic calorimetry are important and should be noted. Based on these results, it is concluded that the use of blast furnace slag should be carefully considered if used for mass concrete applications.

scholarly journals Thermodynamics of Surfactants, Block Copolymers and Their Mixtures in Water: The Role of the Isothermal Calorimetry

2009 ◽  
Vol 10 (7) ◽  
pp. 2873-2895 ◽  
Author(s):  
Rosario De Lisi ◽  
Stefania Milioto ◽  
Nicola Muratore
Keyword(s):  
Block Copolymers ◽  
Isothermal Calorimetry
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