Influence of a Modified Procedure of Joining Ceramic Head and Adapter Sleeve on the Stem Taper in Revision: An Experimental Study.

In revision operations, ceramic heads of modular hip implants can be replaced. As the surface of the stem taper can be damaged, additional adapter sleeves are applied. The components are usually connected manually by the surgeon in a one-step procedure by hammer impacts. In this study, we investigated a two-step joining procedure with reproducible impaction force. First, the adapter sleeve and head were joined quasi-statically with a force of 2 kN using an assembly device. In the second step, these components were applied to the stem taper using a pulse-controlled instrument. For reference, the joints were assembled according to standard conditions using a tensile testing machine. An average pull-off force of 1309 ± 201 N was achieved for the components joined by the instrument, and the average measured values for the components joined by the testing machine were 1290 ± 140 N. All specimens achieved a force >350 N when released and therefore met the acceptance criterion defined for this study. This study showed that a modified procedure in two steps with a defined force has a positive effect on the reproducibility of the measured joining forces compared to previous studies.

Association of Serum Soluble Transferrin Receptor Concentration With Markers of Inflammation: Analysis of 1001 Patients From a Tertiary Rheumatology Center.

OBJECTIVE: Soluble transferrin receptor (sTfR) is considered to be a useful biomarker for the diagnosis of iron deficiency, especially in the setting of inflammation, as it is thought to not be affected by inflammation. We analyzed the relationship between sTfR levels and inflammatory markers in patients with known or suspected inflammatory rheumatic disease (IRD). METHODS: Blood samples of 1001 patients with known or suspected IRD referred to a tertiary rheumatology center were analyzed. Study participants were classified as patients with active IRD and patients with inactive IRD or without IRD. Correlation analyses were used to explore the relationship between sTfR levels and inflammatory markers (ie, C-reactive protein [CRP], erythrocyte sedimentation rate [ESR]). We applied multiple linear regression analysis to evaluate the predictive value of CRP levels for sTfR concentrations after adjustment for potential confounding factors. RESULTS: There were positive correlations between inflammatory markers (CRP, ESR) and serum sTfR levels (ρ 0.44, ρ 0.43, respectively; P < 0.001), exceeding the strength of correlation between inflammatory markers and the acute phase reactant ferritin (ρ 0.30, ρ 0.23, respectively; P < 0.001). Patients with active IRD demonstrated higher serum sTfR levels compared to patients with inactive or without IRD (mean 3.99 [SD 1.69] mg/L vs 3.31 [SD 1.57] mg/L; P < 0.001). After adjustment for potential confounding factors, CRP levels are predictive for serum sTfR concentrations (P < 0.001). CONCLUSION: The study provides evidence against the concept that sTfR is a biomarker not affected by inflammation.

Improving Home-Based Scoliosis Therapy: Findings From a Web-Based Survey.

BACKGROUND: Conservative scoliosis therapy in the form of assisted physiotherapeutic scoliosis exercises is supplemented by self-contained training at home, depending on the approach (eg, Schroth, the Scientific Exercises Approach to Scoliosis). Complex exercises, lack of awareness of the importance of training, and missing supervision by therapists often lead to uncertainty and reduced motivation, which in turn reduces the success of home-based therapy. Increasing digitalization in the health care sector offers opportunities to close this gap. However, research is needed to analyze the requirements and translate the potential of digital tools into concrete solution concepts. OBJECTIVE: The aim of this study is to evaluate the potential for optimizing home-based scoliosis therapy in terms of motivation, assistive devices, and digital tools. METHODS: In collaboration with the Institute of Physiotherapy at the Jena University Hospital, a survey was initiated to address patients with scoliosis and physical therapists. A digital questionnaire was created for each target group and distributed via physiotherapies, scoliosis forums, the Bundesverband für Skoliose Selbsthilfe e. V. newsletter via a link, and a quick response code. The survey collected data on demographics, therapy, exercise habits, motivation, assistive devices, and digital tools. Descriptive statistics were used for evaluation. RESULTS: Of 141 survey participants, 72 (51.1%; n=62, 86.1%, female; n=10, 13.9%, male) patients with scoliosis with an average age of 40 (SD 17.08) years and 30 scoliosis therapists completed the respective questionnaires. The analysis of home-based therapy showed that patients with scoliosis exercise less per week (2 times or less; 45/72, 62.5%) than they are recommended to do by therapists (at least 3 times; 53/72, 73.6%). Patients indicated that their motivation could be increased by practicing together with friends and acquaintances (54/72, 75%), a supporting therapy device (48/72, 66.7%), or a digital profile (46/72, 63.9%). The most important assistive devices, which are comparatively rarely used in home-based therapy, included balance boards (20/72, 27.8%), wall bars (23/72, 31.9%), mirrors (36/72, 50%), and long bars (40/72, 55.6%). Therapists saw the greatest benefit of digital tools for scoliosis therapy in increasing motivation (26/30, 87%), improving home therapy (25/30, 83%), monitoring therapy progress (25/30, 83%), and demonstrating exercise instructions (24/30, 80%). CONCLUSIONS: In this study, we investigated whether there is any potential for improvement in home-based scoliosis therapy. For this purpose, using online questionnaires, we asked patients with scoliosis and therapists questions about the following topics: exercise habits, outpatient and home-based therapy, motivation, supportive devices, and digital tools. The results showed that a lack of motivation, suitable training equipment, and tools for self-control leads to a low training workload. From the perspective of the patients surveyed, this problem can be addressed through community training with friends or acquaintances, a supportive therapy device, and digital elements, such as apps, with training instructions and user profiles.

Stretch Evolution of Electronic Coupling of the Thiophenyl Anchoring Group with Gold in Mechanically Controllable Break Junctions.

The current-voltage characteristics of a single-molecule junction are determined by the electronic coupling Γ between the electronic states of the electrodes and the dominant transport channel(s) of the molecule. Γ is profoundly affected by the choice of the anchoring groups and their binding positions on the tip facets and the tip-tip separation. In this work, mechanically controllable break junction experiments on the N,N'-bis(5-ethynylbenzenethiol-salicylidene)ethylenediamine are presented, in particular, the stretch evolution of Γ with increasing tip-tip separation. The stretch evolution of Γ is characterized by recurring local maxima and can be related to the deformation of the molecule and sliding of the anchoring groups above the tip facets and along the tip edges. A dynamic simulation approach is implemented to model the stretch evolution of Γ, which captures the experimentally observed features remarkably well and establishes a link to the microscopic structure of the single-molecule junction.

Usefulness of Soluble Transferrin Receptor in the Diagnosis of Iron Deficiency Anemia in Rheumatoid Arthritis Patients in Clinical Practice.

Aim: We analyzed the added value of sTfR measurement in routine clinical practice to standard parameters (SP) of iron deficiency in the detection of iron deficiency anemia (IDA) in patients with rheumatoid arthritis (RA). Methods: Blood samples from 116 patients with RA were analyzed in a prospective study. Based on biochemical parameters, patients were classified as having IDA, anemia of chronic disease (ACD), IDA with concomitant ACD (ACD/IDA), or "other anemia." Sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of sTfR and SP of iron status alone and in combination were calculated for the diagnosis of IDA in general, i.e., IDA or ACD/IDA. Results: In the whole sample, with regard to the diagnosis of iron deficiency (IDA or ACD/IDA), sTfR had a higher sensitivity compared both to the combined use of SP and to the combination of SP with sTfR (80.9% versus 66.7/54.8%). Specificity, PPV and NPV did not differ substantially. When patients were stratified in groups with high (CRP levels above the median, i.e., 24.1 mg/l) and low (CRP levels less or equal to the median) inflammation, the diagnostic superiority of sTfR was restricted to patients with high inflammation. In this group, the diagnostic performance of sTfR was superior both to the combined use of SP and the combination of SP with sTfR with higher sensitivity (100% versus 52.4%) and NPV (100% versus 77.7/76.7%) and comparable specificity and PPV. Conclusion: For the detection of iron depletion (IDA or ACD/IDA) in anemic RA patients, sTfR is superior to SP of iron deficiency only in highly inflammatory states.

Unrevealing the interaction between O2 molecules and poly(3-hexylthiophene-2,5-diyl) (P3HT).

Stability of π-conjugated organic materials remains a critical issue for applications in which these materials and devices based on them are exposed to ambient conditions. Particularly, the initial steps of the reversible and irreversible degradation by molecular oxygen exposure are still not fully explored. Here we present a theoretical study using density functional theory (DFT) to investigate the oxygen effects on the electronic properties of poly(3-hexylthiophene-2,5-diyl) (P3HT). Our results show that trap-states are introduced in the energy gap between the highest occupied and the lowest unoccupied molecular orbitals by the O2 molecule and both singlet and triplet states can be formed irrespectively of the existence of chain defects. A crossing between the potential energy surfaces of singlet and triplet states was observed for smaller distances of the oxygen molecule to the nearest thiophene ring, which was identified as being the first step towards irreversible degradation.

[Severe organ manifestations in rheumatic diseases]. / Schwere Organmanifestationen bei rheumatischen Erkrankungen.

Several inflammatory rheumatic diseases can severely affect any organ system and require immediate intervention and intensive care admission. The early detection of impending organ failure and the underlying rheumatic disease is of paramount importance for the prognosis and outcome of affected patients. Therefore, a thorough knowledge of the potential life threatening organ manifestations of systemic rheumatic diseases is of particular interest for clinicians working in intensive care. This paper provides an overview of diagnostic steps and therapy of organ manifestations in critically ill patients with underlying systemic rheumatic diseases. The presentation of the relevant systemic rheumatic diseases is structured according to the most important organ systems, i. e. the respiratory system, the kidney and the cardiovascular system. Furthermore, there is a focus in this paper on macrophage activation syndrome (MAS) as a potentially lethal complication of several rheumatic diseases and the catastrophic antiphospholipid syndrome (CAPS) as a rare cause of multi organ failure.

[Hygiene measures against COVID-19 in routine outpatient care : Acceptance by the patients?] / Hygienemaßnahmen bezüglich COVID-19 in der ambulanten Versorgung : Akzeptanz durch die Patienten?

BACKGROUND: To reduce the risk of SARS-CoV­2 infections, special hygiene measures apply to all German healthcare facilities. Despite the national goals and the existence of comprehensive testing for the detection of asymptomatic or presymptomatic SARS-CoV­2 infections in all inpatients, no equivalent screening with rapid antigen tests has yet been established for outpatients. The acceptance of such screening with associated waiting times and inconvenience for affected patients has been insufficiently investigated. OBJECTIVE: We performed a self-administered anonymous survey of outpatients on their willingness to comply with the hygiene requirements, to undergo rapid antigen screening tests for asymptomatic/presymptomatic infections with SARS-CoV­2 and to receive SARS-CoV­2 vaccination. RESULTS: From 7 to 15 December 2020, 534 patients completed the survey, 195 (37%) from rheumatism and 339 (63%) from orthopedic outpatient clinics. Most patients accepted wearing a mouth-nose covering (475/534, 89%) and attending clinics without an accompanying person to prevent overcrowding of the waiting areas (450/534, 84%). A large majority (428/534 patients, 80%) accepted mandatory screening with rapid antigen tests and the associated waiting time of 15-20 min outside the hospital (449/534, 84%). More than half of the responders reported willingness to receive a SARS-CoV­2 vaccination (yes, immediately 137 (26%), yes, maybe 142 (27%) patients), with significantly (p < 0.05) more male, more rheumatic and more patients older than 60 years indicating a wish to be vaccinated. CONCLUSION: The results revealed a high acceptance of COVID-19 hygiene measures including initial screening by rapid antigen testing.

Sub-picosecond charge-transfer at near-zero driving force in polymer:non-fullerene acceptor blends and bilayers.

Organic photovoltaics based on non-fullerene acceptors (NFAs) show record efficiency of 16 to 17% and increased photovoltage owing to the low driving force for interfacial charge-transfer. However, the low driving force potentially slows down charge generation, leading to a tradeoff between voltage and current. Here, we disentangle the intrinsic charge-transfer rates from morphology-dependent exciton diffusion for a series of polymer:NFA systems. Moreover, we establish the influence of the interfacial energetics on the electron and hole transfer rates separately. We demonstrate that charge-transfer timescales remain at a few hundred femtoseconds even at near-zero driving force, which is consistent with the rates predicted by Marcus theory in the normal region, at moderate electronic coupling and at low re-organization energy. Thus, in the design of highly efficient devices, the energy offset at the donor:acceptor interface can be minimized without jeopardizing the charge-transfer rate and without concerns about a current-voltage tradeoff.

Tuning the conductance of a molecular wire by the interplay of donor and acceptor units.

We investigate the conductance of optimized donor-acceptor-donor molecular wires obtained by on-surface synthesis on the Au(111) surface. A careful balance between acceptors and donors is achieved using a diketopyrrolopyrrole acceptor and two thiophene donors per unit along the wire. Scanning tunneling microscopy imaging, spectroscopy, and conductance measurements done by pulling a single molecular wire at one end are presented. We show that the conductance of the obtained wires is among the highest reported so far in a tunneling transport regime, with an inverse decay length of 0.17 Å-1. Using complex band structure calculations, different donor and acceptor groups are discussed, showing how a balanced combination of donor and acceptor units along the wire can further minimize the decay of the tunneling current with length.

Increased extracellular water measured by bioimpedance and by increased serum levels of atrial natriuretic peptide in RA patients-signs of volume overload.

The aim of the study is to investigate water compartments in patients with rheumatoid arthritis (RA). Acute inflammatory episodes such as infection stimulate water retention, chiefly implemented by the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis. This is an important compensatory mechanism due to expected water loss (sweating etc.). Since SNS and HPA axis are activated in RA, inflammation might be accompanied by water retention. Using bioimpedance analysis, body composition was investigated in 429 controls and 156 treatment-naïve RA patients between January 2008 and December 2014. A group of 34 RA patients was tested before and after 10 days of intensified therapy. Levels of pro-atrial natriuretic peptide (proANP) and expression of atrial natriuretic peptide in synovial tissue were investigated in 15 controls and 14 RA patients. Extracellular water was higher in RA patients than controls (mean ± SEM: 49.5 ± 0.3 vs. 36.7 ± 0.1, % of total body water, p < 0.0001). Plasma levels of proANP were higher in RA than controls. RA patients expressed ANP in synovial tissue, but synovial fluid levels and synovial tissue superfusate levels were much lower than plasma levels indicating systemic origin. Systolic/diastolic blood pressure was higher in RA patients than controls. Extracellular water levels did not change in RA patients despite 10 days of intensified treatment. This study demonstrates signs of intravascular overload in RA patients. Short-term intensification of anti-inflammatory therapy induced no change of a longer-lasting imprinting of water retention indicating the requirement of additional treatment. The study can direct attention to the area of volume overload.

High Conductivity in Molecularly p-Doped Diketopyrrolopyrrole-Based Polymer: The Impact of a High Dopant Strength and Good Structural Order.

[3]-Radialene-based dopant CN6-CP studied herein, with its reduction potential of +0.8 versus Fc/Fc+ and the lowest unoccupied molecular orbital level of -5.87 eV, is the strongest molecular p-dopant reported in the open literature, so far. The efficient p-doping of the donor-acceptor dithienyl-diketopyrrolopyrrole-based copolymer having the highest unoccupied molecular orbital level of -5.49 eV is achieved. The doped films exhibit electrical conductivities up to 70 S cm(-1) .

Lysozyme- and chitinase activity in latex bearing plants of genus Euphorbia--A contribution to plant defense mechanism.

Occurrence of latices in plants is widespread, there are 40 families of plants characterized to establish lactiferous structures. Latices exhibit a constitutive part of plant defense due to the stickiness. The appearance of proteins incorporated in latices is well characterized, and hydrolytic active proteins are considerable. A lot of plants constitute so-called pathogenesis-related (PR) proteins, to overcome stressful conditions. In our investigation we are focused on latex bearing plants of Euphorbiaceae Juss., and investigated the appearance of chitinase- and lysozyme activity in particular. The present outcomes represent a comprehensive study, relating to the occurrence of lysozyme and chitinase activity of genus Euphorbia at the first time. 110 different species of genus Euphorbia L. were tested, and the appearance of chitinase and lysozyme were determined in different quantities. The appearance itself, and the physicochemical properties of latices indicate an efficient interaction for plant defense against pathogen attack.

Tunable dipolar capillary deformations for magnetic Janus particles at fluid-fluid interfaces.

Janus particles have attracted significant interest as building blocks for complex materials in recent years. Furthermore, capillary interactions have been identified as a promising tool for directed self-assembly of particles at fluid-fluid interfaces. In this paper, we develop theoretical models describing the behaviour of magnetic Janus particles adsorbed at fluid-fluid interfaces interacting with an external magnetic field. Using numerical simulations, we test the models predictions and show that the magnetic Janus particles deform the interface in a dipolar manner. We suggest how to utilise the resulting dipolar capillary interactions to assemble particles at a fluid-fluid interface, and further demonstrate that the strength of these interactions can be tuned by altering the external field strength, opening up the possibility to create novel, reconfigurable materials.

Domain and droplet sizes in emulsions stabilized by colloidal particles.

Particle-stabilized emulsions are commonly used in various industrial applications. These emulsions can present in different forms, such as Pickering emulsions or bijels, which can be distinguished by their different topologies and rheology. We numerically investigate the effect of the volume fraction and the uniform wettability of the stabilizing spherical particles in mixtures of two fluids. For this, we use the well-established three-dimensional lattice Boltzmann method, extended to allow for the added colloidal particles with non-neutral wetting properties. We obtain data on the domain sizes in the emulsions by using both structure functions and the Hoshen-Kopelman (HK) algorithm, and we demonstrate that both methods have their own (dis)advantages. We confirm an inverse dependence between the concentration of particles and the average radius of the stabilized droplets. Furthermore, we demonstrate the effect of particles detaching from interfaces on the emulsion properties and domain-size measurements.

Timescales of emulsion formation caused by anisotropic particles.

Particle stabilized emulsions have received much interest in the recent past, but our understanding of the dynamics of emulsion formation is still limited. For simple spherical particles, the time dependent growth of fluid domains is dominated by the formation of droplets, particle adsorption and coalescence of droplets (Ostwald ripening), which eventually can be almost fully blocked due to the presence of the particles. Ellipsoidal particles are known to be more efficient stabilizers of fluid interfaces than spherical particles and their anisotropic shape and the related additional rotational degrees of freedom have an impact on the dynamics of emulsion formation. In this paper, we investigate this point by means of simple model systems consisting of a single ellipsoidal particle or a particle ensemble at a flat interface as well as a particle ensemble at a spherical interface. By applying combined multicomponent lattice Boltzmann and molecular dynamics simulations we demonstrate that the anisotropic shape of ellipsoidal particles causes two additional timescales to be of relevance in the dynamics of emulsion formation: a relatively short timescale can be attributed to the adsorption of single particles and the involved rotation of particles towards the interface. As soon as the interface is jammed, however, capillary interactions between the particles cause a local reordering on very long timescales leading to a continuous change in the interface configuration and increase of the interfacial area. This effect can be utilized to counteract the thermodynamic instability of particle stabilized emulsions and thus offers the possibility to produce emulsions with exceptional stability.

Outpatient management of acute myeloid leukemia after intensive consolidation chemotherapy is feasible and reduces hospital treatment costs.

BACKGROUND: This study assessed the feasibility and safety of out of hospital management of acute myeloid leukemia (AML) patients during consolidation therapy. METHODS: 103 consolidation cycles were analyzed retrospectively. All patients received treatment as inpatients; they were discharged provided they were in a good clinical condition and then either electively readmitted or managed as outpatients during the aplastic phase. RESULTS: In 95/103 cycles (92%), discharge was feasible after a median of 7 (6-16) days. In 45 cycles, patients were electively readmitted at the onset of chemotherapy induced cytopenia after a median time of 12 (9-16) days. In 50 cycles, patients were managed as outpatients. In 23/50 outpatient cycles (46%), patients required rehospitalization, the main cause being neutropenic fever. There was 1 treatment related death due to sepsis in a patient in the outpatient group, accounting for an overall mortality of 2%. Transfusion requirements, occurrence of grade 3-4 toxicity, and disease free and overall survival after a median followup of 20 months did not differ between the treatment strategies. Comparison of diagnosis related group (DRG) proceeds revealed a 40% reduction with the outpatient strategy. CONCLUSION: Outpatient management of consolidation therapy in selected AML patients appears to be feasible and safe and may reduce hospital treatment costs.