Numerical evaluation of internal femur osteosynthesis based on a biomechanical model of the loading in the proximal equine hindlimb.

Femoral fractures are often considered lethal for adult horses because femur osteosynthesis is still a surgical challenge. For equine femur osteosynthesis, primary stability is essential, but the detailed physiological forces occurring in the hindlimb are largely unknown. The objective of this study was to create a numerical testing environment to evaluate equine femur osteosynthesis based on physiological conditions.

Individualized Training of Back Muscles Using Iterative Learning Control of a Compliant Balance Board.

Here we present the GyroTrainer, a bespoke mechatronic balance board system designed to trigger activation of the back muscles while the user engages in a balance-challenging game. The GyroTrainer uses admittance control coupled with an iterative learning approach so as to tailor the admittance control parameters, i.e.

Direct Cyclopalladation of Fluorinated Benzyl Amines by Pd(OAc): The Coexistence of Multinuclear Pd Reaction Pathways Highlights the Importance of Pd Speciation in C-H Bond Activation.

Palladacycles are key intermediates in catalytic C-H bond functionalization reactions and important precatalysts for cross-couplings. It is commonly believed that palladacycle formation occurs through the reaction of a substrate bearing a C-H bond to a suitable metal-directing group for interaction with, typically, mononuclear "Pd(OAc)" species, with cyclopalladation liberating acetic acid as the side product. In this study, we show that ,-dimethyl-fluoro-benzyl amines, which can be cyclopalladated either or to fluorine affording two regioisomeric products, can occur by a direct reaction of Pd(OAc), proceeding via higher-order cyclopalladated intermediates.

The minimum required overlap length for tendon transfer A biomechanical study on human tendons.

In tendon transfer surgeries sufficient stability of the tenorrhaphy is essential. In addition to the choice of a suitable technique, adequate overlap of donor and recipient tendons must be ensured. The aim of this study was to investigate the tensile strength with regard to tendon overlap of a recently published tenorrhaphy, termed Woven-Fridén (WF) tenorrhaphy, which displayed higher tensile strength and lower bulk when compared to the established Pulvertaft technique.

Enantiodiscrimination of Inherently Chiral Thiacalixarenes by Residual Dipolar Couplings.

Inherently chiral compounds, such as calixarenes, are chiral due to a nonplanar three-dimensional (3D) structure. Determining their conformation is essential to understand their properties, with nuclear magnetic resonance (NMR) spectroscopy being one applicable method. Using alignment media to measure residual dipolar couplings (RDCs) to obtain structural information is advantageous when classical NMR parameters like the nuclear Overhauser effect (NOE) or -couplings fail.

Development of an Exoskeleton Platform of the Finger for Objective Patient Monitoring in Rehabilitation.

This paper presents the application of an adaptive exoskeleton for finger rehabilitation. The system consists of a force-controlled exoskeleton of the finger and wireless coupling to a mobile application for the rehabilitation of complex regional pain syndrome (CRPS) patients. The exoskeleton has sensors for motion detection and force control as well as a wireless communication module.

Pulsatile Lavage During Cementation of Total Knee Arthroplasty - Is Fixation Impaired? A Cadaver Study.

Background/aim: Increasing economic pressure in modern healthcare necessitates an increase in efficiency in total knee arthroplasty (TKA) while maintaining high-quality outcomes. Removal of debris using pulsatile lavage (PL) during cement polymerization may considerably reduce the operative duration. However, water can penetrate the interface, resulting in impaired implant fixation.

Fine tuning of the side-to-side tenorrhaphy: A biomechanical study assessing different side-to-side suture techniques in a porcine tendon model.

Recent studies conclude that a new technique for tendon transfers, the side-to-side tenorrhaphy by Fridén (FR) provides higher biomechanical stability than the established standard first described by Pulvertaft (PT). The aim of this study was to optimize side-to-side tenorrhaphies. We compared PT and FR tenorrhaphies as well as a potential improvement, termed Woven-Fridén tenorrhaphy (WF), with regard to biomechanical stability.

Improving mandibular reconstruction by using topology optimization, patient specific design and additive manufacturing?-A biomechanical comparison against miniplates on human specimen.

In this study, topology optimized, patient specific osteosynthesis plates (TOPOS-implants) are evaluated for the mandibular reconstruction using fibula segments. These shape optimized implants are compared to a standard treatment with miniplates (thickness: 1.0 mm, titanium grade 4) in biomechanical testing using human cadaveric specimen.

Exploring the potential of PCA-based quantitation of NMR signals in T relaxometry.

Principal component analysis (PCA) has proved to be a powerful technique for processing NMR data. It is particularly useful in signal quantitation where it often provides better results compared to a direct integration of individual signals. In the present work, we recapitulate the principles and theoretical framework underlying PCA-based quantitation with a special focus on T relaxometry.

Suspension button constructs restore posterior knee laxity in solid tibial avulsion of the posterior cruciate ligament.

Purpose: Dislocated tibial avulsions of the posterior cruciate ligament (PCL) require surgical intervention. Several arthroscopic strategies are options to fix the fragment and restore posterior laxity, including two types of suspension button devices: adjustable (self-locking) and rigid knotted systems. Our hypothesis was that a rigid knotted button construct has superior biomechanical properties regarding laxity restoration compared with an adjustable system.

Nuclear magnetic resonance investigation of water transport through the plasma membrane of various yeast species.

A specific technique of nuclear magnetic resonance (NMR) spectroscopy, filter-exchange spectroscopy (FEXSY), was employed to investigate water transport through the plasma membrane in intact yeast cells. This technique allows water transport to be monitored directly, thus avoiding the necessity to subject the cells to any rapid change in the external conditions, e.g.

Modified suture-bridge technique for tibial avulsion fractures of the posterior cruciate ligament: a biomechanical comparison.

Purpose: Displaced tibial posterior cruciate ligament (PCL) avulsion fractures require surgical fixation in order to provide an adequate bone healing and to avoid a loss of posterior stability. The purpose of this study was to compare the biomechanical properties of a recently established modified suture bridge technique to a well-established transtibial pullout technique. It was hypothesized that the suture bridge technique shows lower elongation and higher load to failure force compared to a transtibial pullout fixation.

Varus alignment increases medial meniscus extrusion and peak contact pressure: a biomechanical study.

Purpose: Assessment of medial meniscus extrusion (MME) has become increasingly popular in clinical practice to evaluate the dynamic meniscus function and diagnose meniscus pathologies. The purpose of this biomechanical study was to investigate the correlation between MME and the changes in joint contact pressure in varus and valgus alignment. It was hypothesized that varus alignment would result in significantly higher MME along with a higher joint contact pressure in the medial compartment.

Varus alignment aggravates tibiofemoral contact pressure rise after sequential medial meniscus resection.

Purpose: Arthroscopic partial meniscectomy of medial meniscus tears and varus alignment are considered independent risk factors for increased medial compartment load, thus contributing to the development of medial osteoarthritis. The purpose of this biomechanical study was to investigate the effect of lower limb alignment on contact pressure and contact area in the knee joint following sequential medial meniscus resection. It was hypothesized that a meniscal resection of 50% would lead to a significant overload of the medial compartment in varus alignment.

Synthesis of the polyketide section of seragamide A and related cyclodepsipeptides via Negishi cross coupling.

The synthesis of the polyketide section present in the potently cytotoxic marine cyclodepsipeptide jasplakinolide and related natural products, geodiamolides and seragamides, is reported. The key step is a Negishi cross coupling of ()-(3-methoxy-2-methyl-3-oxopropyl)zinc(II) bromide and an ()-iodoalkene that was synthesized via an aluminium ester enolate attack at ()-propylene oxide. The overall synthesis comprises nine steps with an overall yield of 21%.

Structural Modulation of Chromic Response: Effects of Binding-Site Blocking in a Conjugated Calix[4]pyrrole Chromophore.

Herein, we modulate the chromic response of a highly colored tetrapyrrole macrocycle, namely, tetrakis(3,5-di--butyl-4-oxocyclohexadien-2,5-yl)porphyrinogen () by structural modification. N-Benzylation at the macrocyclic nitrogen atoms leads to stepwise elimination of the two calix[4]pyrrole-type binding sites of and serial variation of the chromic properties of the products, double N-benzylated and tetra N-benzylated . The halochromic (response to acidity) and solvatochromic (response to solvent polarity) properties were studied by using UV/Vis spectroscopy and NMR spectroscopy in nonpolar organic solvents.

The role of trinuclear species in a palladium acetate/trifluoroacetic acid catalytic system.

Reactions catalyzed by palladium(ii) acetate and trifluoroacetic acid (TFA) have a clear preactivation phase. However, the structure of real catalytic species remains unclear. We show that the key species are cyclic trinuclear complexes of composition [Pd(OAc)(OTFA)] (x = 1-6) formed by a sequential ligand exchange from [Pd(OAc)].

Paramagnetic F Relaxation Enhancement in Nickel(II) Complexes of N-Trifluoroethyl Cyclam Derivatives and Cell Labeling for F MRI.

1,8-Bis(2,2,2-trifluoroethyl)cyclam (te2f) derivatives with two coordinating pendant arms involving methylenecarboxylic acid (Hte2f2a), methylenephosphonic acid (Hte2f2p), (2-pyridyl)methyl (te2f2py), and 2-aminoethyl arms (te2f2ae) in 4,11-positions were prepared, and their nickel(II) complexes were investigated as possible F MR tracers. The solid-state structures of several synthetic intermediates, ligands, and all complexes were confirmed by X-ray diffraction analysis. The average Ni···F distances were determined to be about 5.

Total Synthesis of the Marine Natural Product Hemiasterlin by Organocatalyzed α-Hydrazination.

An efficient synthesis of the potently cytotoxic marine peptide hemiasterlin is presented. The tetramethyltryptophan moiety is assembled by tert-prenylation of indole, followed by the high-yielding organocatalyzed α-hydrazination of a sterically congested aldehyde with excellent enantioselectivity. 2-Bromo-N-ethylpyridinium tetrafluoroborate (BEP)-mediated peptide coupling completes the synthesis, being the first approach that does not employ chiral auxiliaries.

Nanoscaled porphyrinic metal-organic frameworks: photosensitizer delivery systems for photodynamic therapy.

The photocytotoxic activity of porphyrin-containing materials including metal-organic frameworks (MOFs) has attracted ever increasing interest. We have developed a simple synthesis of hexagonal PCN-222/MOF-545 nanoparticles, which are powerful in inducing reactive oxygen species-mediated apoptosis of cancer cells upon visible light irradiation. The extent of the cytotoxic effect well correlates with the nanoparticle size and structural instability.

Decay of (,)-Fourier coefficients.

We show that essentially the speed of decay of the Fourier sine coefficients of a function in a Lebesgue space is comparable to that of the corresponding coefficients with respect to the basis formed by the generalized sine functions sin .

Determination of size of molecular clusters of ethanol by means of NMR diffusometry and hydrodynamic calculations.

The microscopic structure of ethanol in the liquid state is characterized as a dynamic equilibrium of hydrogen-bonded clusters of different sizes and topologies. We have developed a novel method for determination of the average size of the clusters that combines the measurement of diffusion coefficient by means of NMR diffusometry technique and hydrodynamic simulations. The approach includes the use of HydroNMR [J.

Inclusion of chloromethane guests affects conformation and internal dynamics of cryptophane-D host.

Cryptophane-D is composed of two nonequivalent cyclotribenzylene caps bound together by three OCH2CH2O bridges in a syn arrangement. Host-guest complexes with chloroform and dichloromethane were investigated in solution by NMR spectroscopy. Variable temperature NMR (1)H and (13)C spectra showed effects of chemical exchange between the free and bound guest and of conformational exchange for the host, strongly and specifically affected by guest binding.

Oligomerization of a retroviral matrix protein is facilitated by backbone flexibility on nanosecond time scale.

The oligomerization capacity of the retroviral matrix protein is an important feature that affects assembly of immature virions and their interaction with cellular membrane. A combination of NMR relaxation measurements and advanced analysis of molecular dynamics simulation trajectory provided an unprecedentedly detailed insight into internal mobility of matrix proteins of the Mason-Pfizer monkey virus. Strong evidence have been obtained that the oligomerization capacity of the wild-type matrix protein is closely related to the enhanced dynamics of several parts of its backbone on a nanosecond time scale.