Atrial fibrillation (AF) is the most prevalent sustained arrhythmia in clinical practice. It is associated with significant
morbidity and mortality and has been identified as an independent risk ...factor for ischemic stroke and thromboembolic
events. Catheter ablation has become an established rhythm control therapy in patients with highly symptomatic
drug-refractory AF. The definition of ablation success remains controversial since current symptom-based or intermittent
electrocardiogram monitoring strategies fail to sufficiently disclose rhythm outcome. This failure is mainly related to the
high incidence of asymptomatic AF recurrences, the unpredictable nature of arrhythmia relapses, and the poor correlation
of symptoms and AF episodes. There is a clear correlation between the intensity of the monitoring strategy and the sensitivity
for it to detect arrhythmia recurrences. Furthermore, several clinical studies assessing the long-term efficacy of
catheter ablation procedures have reported late AF recurrences in patients who were initially considered responders to
catheter ablation. In certain subsets of patients, precise long-term monitoring may help to guide therapy, e.g. patients in
whom withdrawal of antithrombotic therapy may be considered if they are free of arrhythmia recurrences. Recently, subcutaneous
implantable cardiac monitors (ICM) have been introduced for prolonged and continuous rhythm monitoring.
The performance of a leadless ICM equipped with a dedicated AF detection algorithm has recently been assessed in a
clinical trial demonstrating a high sensitivity and overall accuracy for identifying patients with AF. The clinical impact of
ICM-based follow-up strategies, however, has to be evaluated in prospective clinical trials.
Background
The goal was to test the effectiveness of a structured pain management programme after invasive electrophysiological interventions in cardiology including ablation of atrial fibrillation ...(AF) or ventricular tachycardia (VT) and implantation, or explantation, of pacemakers or implantable cardioverter defibrillators.
Methods
This was a prospective study with a pre‐/post‐design where a post‐intervention group (116 consecutive patients) was compared to a pre‐intervention group (102 consecutive patients) after implementation of a structured pain‐management programme using the numeric rating scale (NRS 0–10) and classified as moderate‐to‐severe if NRS > 3. Measurements were recorded every two hours during the first 24 h post‐operatively. The location of the pain and the amount of analgesic used were also recorded.
Results
The proportion of patients who experienced moderate‐to‐severe pain after the procedure decreased after initiation of the pain‐management program: 47% versus 61%; p = 0.048. This difference was driven primarily by reduced pain late (8–24 h) after the procedure; 16% versus 39%; p < 0.001. The risk to develop late (8–24 h) post‐procedural pain was reduced approximately three‐fold after implementation of the pain‐management programme (OR = 0.32, 95% CI 0.16–0.64, p = 0.001). Multivariate analysis indicated chronic pain, early pain (0–6 h), and type of intervention were associated with late post‐interventional pain. In contrast, age, diabetes mellitus, BMI, gender and procedure time were not related.
Conclusion
The findings illustrate the potential value of a structured pain‐management programme. The proportion of patients who experienced moderate‐to‐severe pain after these electrophysiological procedures decreased significantly.
Significance
This is the first exploratory study that evaluates the impact of a multidisciplinary pain‐management programme after cardiac electrophysiological interventions. It demonstrates that significant quality improvement is achievable following simple rules together with patient and staff education. The programme reduces the proportion of patients with moderate‐to‐severe pain after electrophysiological procedures significantly.
Previous work assumed that ATP synthase, the smallest known rotary motor in nature, operates at 100% efficiency. Calculations which arrive to this result assume that the water viscosity inside ...mitochondria is constant and corresponds to that of bulk water. In our opinion this assumption is not satisfactory for two reasons: (1) There is evidence that the water in mitochondria prevails to 100% as interfacial water. (2) Laboratory experiments which explore the properties of interfacial water suggest viscosities which exceed those of bulk water, specifically at hydrophilic interfaces. Here, we wish to suggest a physicochemical mechanism which assumes intramitochondrial water viscosity gradients and consistently explains two cellular responses: The decrease and increase in ATP synthesis in response to reactive oxygen species and non-destructive levels of near-infrared (NIR) laser light, respectively. The mechanism is derived from the results of a new experimental method, which combines the technique of nanoindentation with the modulation of interfacial water layers by laser irradiation. Results, including the elucidation of the principle of light-induced ATP production, are expected to have broad implications in all fields of medicine.
This article presents a collaborative study to determine the condition within volumes of the Great and Little Domesday Book, held in The National Archives, UK. Advances in technology in both ...biochemical and biophysical analysis have allowed for the first time undetectable sub milligram sampling of the five-volume Great and Little Domesday Books at nine sites in total. Visual analysis was followed by microscopic fibre assessment, hydrothermal stability (shrinkage activity), amino acid analysis and microfocus X-ray diffraction. Based on the visual examination of 887 leaves in all five volumes of the Domesday Book, 587 leaves or 66% of the leaves exhibit a degree of surface gelatinisation due in part to humidification and pressing practices carried out as part of the many re-binding campaigns carried out over the centuries. Microfibre assessment indicated the percentage of damaged fibres detected varies from 56 to 100% in the samples taken, a correlation between the sum of oxidative sensitive amino acids and the observed damage of fibres was obtained. More than 1000 X-ray diffraction patterns collected showed a significant variation in amount of visible fibrillar collagen within each sample scan. Micro analysis performed here on corium collagen, means the results represent an average of the cross section of the structure of which the surface constitutes the smallest part. As the major part of damage is on the surface of the parchment leaves, the condition is likely to be worse than that reflected by the analytical results shown here. This evidence therefore prompted a re-think of the preservation protocols required to extend the usable life of the Domesday Book volumes. To this end, the preservation environment for the volumes is maintained at 40–45% relative humidity (RH) significantly lower than the recommended parameter of 55% RH.
Rheological behaviour of reconstructed skin Pailler-Mattei, C.; Laquièze, L.; Debret, R. ...
Journal of the mechanical behavior of biomedical materials,
09/2014, Letnik:
37
Journal Article
Recenzirano
Reconstructed skins have been developed to replace skin when the integrity of tissue has been compromised following severe injury, and to provide alternative methods validating the innocuousness and ...effectiveness of dermatological and cosmetic products. However the functional properties of tissue substitutes have not been well characterised, mainly since mechanical measurement devices have not been designed to test cell culture materials in vitro. From the mechanical standpoint, reconstructed skin is a heterogeneous multi-layer viscoelastic material. To characterise the time-dependent behaviour of reconstructed skin, spherical indentation load-relaxation tests were performed with a specific original device adapted to measure small soft tissue samples. Load-relaxation indentation tests were performed on a standard reconstructed skin model and on sub-components of the reconstructed skin (3D-scaffold alone and dermal equivalent). Generalised Maxwell and Kelvin–Voigt rheological models are proposed for analysing the mechanical behaviour of each biological tissue. The results indicated a modification of the rheological behaviour of the samples tested as a function of their biological structure. The 3D-scaffold was modelled using the one-branch Maxwell model, while the dermis equivalent and the reconstructed skin were modeled using a one-branch and a two-branch Kelvin–Voigt model, respectively. Finally, we demonstrated that skin cells contribute to global mechanical behaviour through an increase of the instantaneous relaxation function, while the 3D-scaffold alone influences the mechanical response of long relaxation times.
Drug repositioning is a strategy that identifies new uses of approved drugs to treat conditions different from their original purpose. Current efforts to treat Covid-19 are based on this strategy. ...The first drugs used in patients infected with SARS-CoV-2 were antimalarial drugs. It is their mechanism of action, i. e., rise in endosomal pH, which recommends them against the new coronavirus. Disregarding their side effects, the study of their antiviral activity provides valuable hints for the choice and design of drugs against SARS-CoV-2. One prominent drug candidate is thymoquinone, an antimalarial substance contained in Nigella sativa - most likely one of the first antimalarial drugs in human history. Since the outbreak of the pandemic, the number of articles relating thymoquinone to Covid-19 continuously increases. Here, we use it as an exemplary model drug, compare its antiviral mechanism with that of conventional antimalarial drugs and establish an irreducible parametric scheme for the identification of drugs with a potential in Covid-19.Translation into the laboratory is simple. Starting with the discovery of Nigella sativa seeds in the tomb of Pharaoh Tutankhamun, we establish a physicochemical model for the interaction of thymoquinone with both coronavirus and cells. Exploiting the predictive capability of the model, we provide a generalizable scheme for the systematic choice and design of drugs for Covid-19. An unexpected offshoot of our research is that Tutankhamun could not have died of malaria, a finding contrary to the mainstream theory.
A limited number of bacteria, yeast and fungi can convert hemicellulose or its monomers (xylose, arabinose, mannose and galactose) into ethanol with a satisfactory yield and productivity. In the ...present study we tested a number of thermophilic enrichment cultures, and new isolates of thermophilic anaerobic bacterial strains growing optimally at 70-80 degrees C for their ethanol production from D-xylose. The new isolates came from different natural and man-made systems such as hot springs, paper pulp mills and brewery waste water. The test was composed of three different steps; (i) test for conversion of D-xylose into ethanol; (ii) test for viability and ethanol production in pretreated wheat straw hemicellulose hydrolysate; (iii) test for tolerance against high D-xylose concentrations. A total of 86 enrichment cultures and 58 pure cultures were tested and five candidates were selected which successfully fulfilled the criteria defined for the screening test.
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