Robotic Assisted TKA achieves adjusted mechanical alignment targets more consistently compared to manual TKA without improving outcomes.

Introduction: Robotic total knee arthroplasty (rTKA), with its purported advantages of more accurate alignment, greater functional outcomes and patient satisfaction, is gaining popularity in patients undergoing TKA. The purpose of our study was to compare these parameters along with gait pattern and kneeling ability in a cohort of patients who underwent simultaneous TKA with manual instrumentation (mTKA) and rTKA in contralateral knees at a 1-year follow-up.

Methods: This was a retrospective review of 135 consecutive patients who underwent simultaneous bilateral TKA using robotic assistance on one side and manual instrumentation on the contralateral side between January 2022 and June 2022.

Automated trichome counting in soybean using advanced image-processing techniques.

Premise: Trichomes are hair-like appendages extending from the plant epidermis. They serve many important biotic roles, including interference with herbivore movement. Characterizing the number, density, and distribution of trichomes can provide valuable insights on plant response to insect infestation and define the extent of plant defense capability.

Formation of Size and Density Controlled Nanostructures by Galvanic Displacement.

Gold (Au) and copper (Cu)-based nanostructures are of great interest due to their applicability in various areas including catalysis, sensing and optoelectronics. Nanostructures synthesized by the galvanic displacement method often lead to non-uniform density and poor size distribution. Here, density and size-controlled synthesis of Au and Cu-based nanostructures was made possible by galvanic displacement with limited exposure to hydrofluoric (HF) acid and the use of surfactants like L-cysteine (L-Cys) and cetyltrimethylammonium bromide (CTAB).

Rheological transition in simple shear of moderately dense assemblies of dry cohesive granules.

The rheology of homogeneous cohesive granular assemblies under shear at moderate volume fractions is investigated using the discrete element method for both frictionless and frictional granules. A transition in rheology from inertial to quasistatic scaling is observed at volume fractions below the jamming point of noncohesive systems, which is a function of the granular temperature, energy dissipation, and cohesive potential. The transition is found to be the result of growing clusters, which eventually percolate the domain, and change the mode of momentum transport in the system.

An alternative method to determining optical lever sensitivity in atomic force microscopy without tip-sample contact.

Force studies using atomic force microscopy generally require knowledge of the cantilever spring constants and the optical lever sensitivity. The traditional method of evaluating the optical lever sensitivity by pressing the tip against a hard surface can damage the tip, especially sharp ones. Here a method is shown to calculate the sensitivity without having to bring the tip into contact.

Atom scale characterization of the near apex region of an atomic force microscope tip.

Three-dimensional atom probe tomography (APT) is successfully used to analyze the near-apex regions of an atomic force microscope (AFM) tip. Atom scale material structure and chemistry from APT analysis for standard silicon AFM tips and silicon AFM tips coated with a thin film of Cu is presented. Comparison of the thin film data with that observed using transmission electron microscopy indicates that APT can be reliably used to investigate the material structure and chemistry of the apex of an AFM tip at near atomic scales.

Friction and wear behavior of ultrahigh molecular weight polyethylene as a function of crystallinity in the presence of the phospholipid dipalmitoyl phosphatidylcholine.

In this study, the friction and wear behavior of ultrahigh molecular weight polyethylene (UHMWPE) were evaluated as a function of polymer crystallinity in the presence of the phospholipid dipalmitoyl phosphatidylcholine (DPPC) dissolved in ethanol. Samples of UHMWPE were separately heat treated to get high and low crystallinity samples. Degree of crystallinity was evaluated using differential scanning calorimetry.

Nanoscale friction switches: friction modulation of monomolecular assemblies using external electric fields.

This paper presents experimental investigations to actively modulate the nanoscale friction properties of a self-assembled monolayer (SAM) assembly using an external electric field that drives conformational changes in the SAM. Such "friction switches" have widespread implications in interfacial energy control in micro/nanoscale devices. Friction response of a low-density mercaptocarboxylic acid SAM is evaluated using an atomic force microscope (AFM) in the presence of a DC bias applied between the sample and the AFM probe under a nitrogen (dry) environment.

Visualization by atomic force microscopy and FISH of the 45S rDNA gaps in mitotic chromosomes of Lolium perenne.

The mitotic chromosome structure of 45S rDNA site gaps in Lolium perenne was studied by atomic force microscope (AFM) combining with fluorescence in situ hybridization (FISH) analysis in the present study. FISH on the mitotic chromosomes showed that 45S rDNA gaps were completely broken or local despiralizations of the chromatid which had the appearance of one or a few thin DNA fiber threads. Topography imaging using AFM confirmed these observations.

Iterative control approach to high-speed force-distance curve measurement using AFM: time-dependent response of PDMS example.

Force-distance curve measurements using atomic force microscope (AFM) has been widely used in a broad range of areas. However, currently force-curve measurements are hampered the its low speed of AFM. In this article, a novel inversion-based iterative control technique is proposed to dramatically increase the speed of force-curve measurements.

Friction and wear behavior of ultra-high molecular weight polyethylene as a function of polymer crystallinity.

In this study the friction, wear and surface mechanical behavior of medical-grade ultra-high molecular weight polyethylene (UHMWPE) (GUR 1050 resin) were evaluated as a function of polymer crystallinity. Crystallinity was controlled by heating UHMWPE to a temperature above its melting point and varying the hold time and cooling rates. The degree of crystallinity of the samples was evaluated using differential scanning calorimetry (DSC).

Method to generate surfaces with desired roughness parameters.

A surface engineering method based on the electrostatic deposition of microparticles and dry etching is described and shown to be able to independently tune both amplitude and spatial roughness parameters of the final surface. Statistical models were developed to connect process variables to the amplitude parameters (center line average and root-mean-square) and a spatial parameter (autocorrelation length) of the final surfaces. Process variables include particle coverage, which affects both amplitude and spatial roughness parameters, particle size, which affects only spatial parameters, and etch depth, which affects only amplitude parameters.

Comparison of the effect of surface roughness on the micro/nanotribological behavior of ultra-high-molecular-weight polyethylene (UHMWPE) in air and bovine serum solution.

Tribological properties of materials used in biomedical implants critically affect the performance of the implant. A UHMWPE cup paired with a ceramic ball is a popular combination for implants due to its relatively low wear rate. In this study we investigate the effect of surface roughness of UHMWPE on the friction behavior and onset of wear in a UHMWPE/silicon nitride interface in both dry air and bovine serum environments.

Mechanical property measurements of nanoscale structures using an atomic force microscope.

This paper describes nanometer-scale bending tests of fixed single-crystal silicon (Si) and silicon dioxide (SiO2) nanobeams using an atomic force microscope (AFM). The technique is used to evaluate elastic modulus of the beam materials and bending strength of the beams. Nanometer-scale Si beams with widths ranging from 200 to 800 nm were fabricated on a Si diaphragm using field-enhanced anodization using an AFM followed by anisotropic wet etching.