Patient-specific scaphoid prosthesis: surgical technique.

The scaphoid bone is essential for wrist stability, force transmission, and movement, being crucial for maintaining carpal kinematics. In cases where the scaphoid is non-reconstructable, a complete replacement can serve as a treatment option to preserve carpal alignment and motion. This approach has evolved since its first descriptions in 1945, benefiting significantly from advancements in patient-specific implant design, additive manufacturing/3D printing, and material use in recent years.

Bilateral symmetry assessment of healthy forearm kinematics using 4D-CT.

Advanced stage distal radio-ulnar joint (DRUJ) injury may warrant radius corrective osteotomy or arthroplasty. These procedures aim to restore geometry, function and kinematics and could benefit from preoperative planning where the contralateral forearm is typically used as reference. Natural variations regarding geometry and function between forearms are known but kinematic differences are not.

Performance of the Aptis Distal Radioulnar Joint Implant: A Clinical Case Series Including Four-Dimensional Computed Tomography Kinematic Analysis.

High complication rates and surgical revision rates following Aptis implant placement have been reported in the literature. This study evaluates the performance of the Aptis implant of twelve patients using four-dimensional kinematic analysis. The (mean) follow-up was 58 months.

Quantification of the methodological error in kinematic evaluation of the DRUJ using dynamic CT.

Distal radio-ulnar joint (DRUJ) motion analysis using dynamic CT is gaining popularity. Following scanning and segmentation, 3D bone models are registered to (4D-)CT target frames. Imaging errors like low signal-to-noise ratio (SNR), limited Z-coverage and motion artefacts influence registration, causing misinterpretation of joint motion.

Kinematic analysis of forearm rotation using four-dimensional computed tomography.

This study aimed to quantify forearm kinematics with a focus on the forearm rotation axis. Ten healthy volunteers were included in the study. One three-dimensional computed tomographic scan and two four-dimensional computed tomographic scans were done in all the arms to capture forearm joint motion.

Cold, clumpy accretion onto an active supermassive black hole.

Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecular clouds--a departure from the 'hot mode' accretion model--although unambiguous observational support for this prediction remains elusive.

Jet acceleration of the fast molecular outflows in the Seyfert galaxy IC 5063.

Massive outflows driven by active galactic nuclei are widely recognized to have a key role in the evolution of galaxies, by heating the ambient gas, expelling it from the nuclear regions, and thereby affecting the star-formation histories of the galaxy bulges. It has been proposed that the powerful jets of relativistic particles (such as electrons) launched by some active nuclei can both accelerate and heat the molecular gas, which often dominates the mass budgets of the outflows. Clear evidence for this mechanism, in the form of detailed associations between the molecular gas kinematics and features in the radio-emitting jets, has however been lacking.

Zebrafish embryo development in a microfluidic flow-through system.

The zebrafish embryo is a small, cheap, whole-animal model which may replace rodents in some areas of research. Unfortunately, zebrafish embryos are commonly cultured in microtitre plates using cell-culture protocols with static buffer replacement. Such protocols are highly invasive, consume large quantities of reagents and do not readily permit high-quality imaging.

Ganglioside storage, hexosaminidase lability, and urinary oligosaccharides in adult Sandhoff's disease.

Two adult sisters with severe spinocerebellar degeneration were deficient in hexosaminidase A and B. GM2 ganglioside storage in brain tissue obtained by autopsy from one patient was most pronounced in the cerebellum. Hexosaminidase activity in brain tissue was negligible, but fibroblasts from the second patient contained relatively high amounts of heat-labile activities of both isoenzymes.

Spinocerebellar degeneration: hexosaminidase A and B deficiency in two adult sisters.

Two adult sisters had spinocerebellar degeneration. Biochemical studies revealed a very low activity of both fraction A and fraction B of the lysosomal enzyme, hexosaminidase, in serum and leukocytes. A skin biopsy showed lesions suggestive of neuronal storage disease.