Mechanical Properties of Viruses.

Structural biology techniques have greatly contributed to unveiling the interplay between molecular structure, physico-chemical properties, and biological function of viruses. In recent years, classic structural approaches are being complemented by single-molecule techniques such as atomic force microscopy and optical tweezers to study physical features of viral particles that are not accessible to classic structural techniques. Among these features are mechanical properties such as stiffness, intrinsic elasticity, tensile strength, and material fatigue.

Atomic Force Microscopy of Viruses.

Atomic force microscopy (AFM) makes it possible to obtain images at nanometric resolution, and to accomplish the manipulation and physical characterization of specimens, including the determination of their mechanical and electrostatic properties. AFM has an ample range of applications, from materials science to biology. The specimen, supported on a solid surface, can be imaged and manipulated while working in air, ultra-high vacuum or, most importantly for virus studies, in liquid.

Broad Adaptability of Coronavirus Adhesion Revealed from the Complementary Surface Affinity of Membrane and Spikes.

Coronavirus stands for a large family of viruses characterized by protruding spikes surrounding a lipidic membrane adorned with proteins. The present study explores the adhesion of transmissible gastroenteritis coronavirus (TGEV) particles on a variety of reference solid surfaces that emulate typical virus-surface interactions. Atomic force microscopy informs about trapping effectivity and the shape of the virus envelope on each surface, revealing that the deformation of TGEV particles spans from 20% to 50% in diameter.

Predictors of quality of life, functional status, depression and fatigue in early arthritis: comparison between clinically suspect arthralgia, unclassified arthritis and rheumatoid arthritis.

Background: Rheumatoid arthritis (RA) is often preceded by symptomatic phases during which classification criteria are not fulfilled. The health burden of these "at-risk" stages is not well described. This study assessed health-related quality of life (HRQoL), function, fatigue and depression in newly presenting patients with clinically suspect arthralgia (CSA), unclassified arthritis (UA) or RA.

Gutless Helper-Dependent and First-Generation HAdV5 Vectors Have Similar Mechanical Properties and Common Transduction Mechanisms.

Delivering vectorized information into cells with the help of viruses has been of high interest to fundamental and applied science, and bears significant therapeutic promise. Human adenoviruses (HAdVs) have been at the forefront of gene delivery for many years, and the subject of intensive development resulting in several generations of agents, including replication-competent, -defective or retargeted vectors, and recently also helper-dependent (HD), so-called gutless vectors lacking any viral protein coding information. While it is possible to produce HD-AdVs in significant amounts, physical properties of these virus-like particles and their efficiency of transduction have not been addressed.