Most reservoir fluids contain heavy paraffinic compounds that may precipitate as a solid or solid like material called wax if the fluid is cooled down. Wax precipitation is a phenomenon of considerable importance in oil industry. An increase in aggregation results in enhanced oil viscosity. This however causes significant negative effects on production, transportation and processing of crude oi...

INTRODUCTION In the past decade, the field of single-molecule mechanics has grown rapidly, and through the use of techniques such as atomic-force microscopy (AFM) and optical tweezers, much has been learned about the molecular mechanisms responsible for mechanical response [1]. In spite of this, there have been few studies relating mechanical response across a range of hierarchies, in order to ...

Human serum albumin (HSA) is the most abundant protein in the blood plasma. Drug binding to HSA is crucial to study the absorption, distribution, metabolism, efficiency and bioavailability of drug molecules. In this study, isothermal titration calorimetry and molecular dynamics simulation of HSA and its complex with indometacin (IM) were performed to investigate thermodynamics parameters and th...

This paper investigates the lateral vibration of single-layered graphene sheets based on a new theory called doublet mechanics with a length scale parameter. After a brief reviewing of doublet mechanics fundamentals, a sixth order partial differential equation that governs the lateral vibration of single-layered graphene sheets is derived. Using doublet mechanics, the relation between natural f...

Objective(s): The novel 7-hydroxycoumarinyl gallates derivatives are detected in many pharmaceutical compounds like anticancer and antimicrobial agents. Whereas carbon nanotubes (CNTs) have been discussed for nanomedicine applications and in particular as drug delivery systems. The capability of armchair (5, 5) SWCNT -based drug delivery system in the therapy of anticancer has been investigated...

Quantum mechanics/molecular mechanics (QM/MM) hybrid methods are currently the most powerful computational tools for studies of structure/function relations and catalytic sites embedded in macrobiomolecules (eg, proteins and nucleic acids). QM/MM methodologies are highly efficient since they implement quantum chemistry methods for modeling only the portion of the system involving bond-breaking/...

The histone-DNA interaction in the nucleosome is a fundamental mechanism of genomic compaction and regulation, which remains largely unknown despite increasing structural knowledge of the complex. In this paper, we propose a framework for the extraction of a nanoscale histone-DNA force-field from a collection of high-resolution structures, which may be adapted to a larger class of protein-DNA c...

The S1 → S2 transition of the oxygen-evolving complex (OEC) of photosystem II does not involve the transfer of a proton to the lumen and occurs at cryogenic temperatures. Therefore, it is commonly thought to involve only Mn oxidation without any significant change in the structure of the OEC. Here, we analyze structural changes upon the S1 → S2 transition, as revealed by quantum mechanics/molec...