The first human experience of a contact force sensing catheter for epicardial ablation of ventricular tachycardia

Contact force (CF) is one of the major determinants for sufficient lesion formation. CF-guided procedures are associated with enhanced lesion formation and procedural success.We report our initial experience in epicardial ventricular tachycardia (VT) ablation with a force-sensing catheter using a new approach with an angioplasty balloon. Two patients with arrhythmogenic right ventricular cardiomyopathy who underwent prior unsuccessful endocardial ablation were treated with epicardial VTablation. CF data were used to titrate force, power and ablation time

Study of Digital Competence of the Students and Teachers in Ukraine

Professional fulfillment of the personality at the conditions of the digital economy requires the high level of digital competency. One of the ways to develop these competencies is education. However, to provide the implementation of digital education at a high level, the digital competency of the teachers and students is a must. This paper presents explanations on the level determination of the digital competencies for teachers and students in Ukraine according to the DigComp recommendations. We tried to identify the main factors that reflect the degree of readiness teachers and students for digital education based on their self-evaluation. We also attempted to estimate the level of digital competencies based on the analysis of Case-Studies execution results. The complex analysis let us assess the connection between respondents’ self-evaluation and their real competencies. Here we provide a methodology and a model of level competencies determination by means of a survey, expert case rating and the results of the statistical analysis. On the basis of the obtained results, this paper suggests further research prospects and recommendations on the digital competency development in educational institutions in Ukraine

Clinical outcome of ablation for long-standing persistent atrial fibrillation with or without defragmentation

Objective To assess the outcome and associated risks of atrial defragmentation for the treatment of long-standing persistent atrial fibrillation (LSP-AF). Methods Thirty-seven consecutive patients (60.4±7.3 years; 28 male) suffering from LSP-AF who underwent pulmonary vein isolation (PVI) and linear ablation were compared. All patients were treated with the Stereotaxis magnetic navigation system (MNS). Two groups were distinguished: patients with (n =20) and without (n =17) defragmentation. The primary endpoint of the study was freedom of AF after 12 months. Secondary endpoints were AF termination, procedure time, fluoroscopy time and procedural complications. Complications were divided into two groups: Major (infarction, stroke, major bleeding and tamponade) and minor (fever, pericarditis and inguinal haematoma). Results No difference was seen in freedom of AF between the defragmentation and the non-defragmentation group (56.2 % vs. 40.0%, P=0.344). Procedure times in the defragmentation group were longer; no differences in fluoroscopy times were observed. No major complications occurred. A higher number of minor complications occurred in the defragmentation group (45.0 % vs. 5.9 %, P=0.009). Mean hospital stay was comparable (4.7±2.2 vs. 3.4±0.8 days, P=0.06). Conclusion Our study suggests that complete defragmentation using MNS is associated with a higher number of minor complications and longer procedure times and thus compromises efficiency without improving efficacy

Space Division Multiplexed Optical Coherence Tomography on a Silicon Chip―An Experimental and Numerical Analysis of Potential Artifacts

This work presents a detailed experimental and numerical study of a multi-arm on-chip optical coherence tomography (OCT) system employing a space division multiplexing (SDM) approach. While SDM-OCT systems promise enhanced imaging speeds, they also introduce complexities in signal processing due to challenges like crosstalk between ports, cross-referencing, multiple reflections among the sample, chip, and input fiber facet, as well as mixed polarization states of light. To address these challenges, we developed and characterized single-arm and four-arm on-chip SDM-OCT systems using a low-loss silicon nitride platform. Through rigorous experiments, we identified the key sources of artifacts and numerically validated their effects. Furthermore, we proposed practical strategies to mitigate these issues. We believe our experimental findings, numerical analysis, and proposed solutions provide a robust foundation for advancing SDM-OCT system designs in future research.</p

The Association of the Dark Tetrad With the Ability to Feign Schizophrenia

Objective: Since its third edition (American Psychiatric Association, 1980) and in subsequent editions, the Diagnostic and Statistical Manual of Mental Disorders has favored the criminological model in relation to malingering. However, research on the relationship of psychopathy and antisocial personality disorder to the propensity and ability to feign mental illness has yielded mixed results. Importantly, no study has yet examined the relationship between the Dark Tetrad (Machiavellianism, narcissism, psychopathy, and sadism) and the ability to fake mental illness in a credible manner. Our study aimed to fill this research gap by examining whether individuals with higher Dark Tetrad traits report more schizophrenia symptoms and more credibly fake schizophrenia when asked to do so. Method: Eighty-one nonclinical volunteers from Portugal took the Short Dark Tetrad (SD4) and were instructed to respond honestly. They were then instructed to feign schizophrenia on the following tests: the Eppendorf Schizophrenia Inventory (ESI), the Inventory of Problems–29 (IOP-29), and the memory add-on of the IOP-29 (i.e., IOP-M). Results: None of the SD4 scores correlated significantly with the ESI, IOP-29, and IOP-M scores, and all effect sizes were small. Of note, the standard cutoff score of the IOP-29 (i.e., =.50) correctly classified 90.1% of participants as fakers (i.e., sensitivity =.90), and half of the very few false-negative classifications of the IOP-29 were correctly classified as noncredible results by the IOP-M. Conclusions: The ability to plausibly fake schizophrenia is comparable in individuals with higher and lower Dark Tetrad traits. Also, the IOP-29 and the IOP-M showed excellent validity, further supporting their effectiveness in assessing symptom and performance validity

Nitrous oxide may not increase the risk of cancer recurrence after colorectal surgery: a follow-up of a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Even the best cancer surgery is usually associated with minimal residual disease. Whether these remaining malignant cells develop into clinical recurrence is at least partially determined by adequacy of host defense, especially natural killer cell function. Anesthetics impair immune defenses to varying degrees, but nitrous oxide appears to be especially problematic. We therefore tested the hypothesis that colorectal-cancer recurrence risk is augmented by nitrous oxide administration during colorectal surgery.</p> <p>Methods</p> <p>We conducted a 4- to 8-year follow-up of 204 patients with colorectal cancer who were randomly assigned to 65% nitrous oxide (n = 97) or nitrogen (n = 107), balanced with isoflurane and remifentanil. The primary outcome was the time to cancer recurrence. Our primary analysis was a multivariable Cox-proportional-hazards regression model that included relevant baseline variables. In addition to treatment group, the model considered patient age, tumor grade, dissemination, adjacent organ invasion, vessel invasion, and the number of nodes involved. The study had 80% power to detect a 56% or greater reduction in recurrence rates (i.e., hazard ratio of 0.44 or less) at the 0.05 significance level.</p> <p>Results</p> <p>After adjusting for significant baseline covariables, risk of recurrence did not differ significantly for nitrous oxide and nitrogen, with a hazard ratio estimate (95% CI) of 1.10 (0.66, 1.83), <it>P </it>= 0.72. No two-way interactions with the treatment were statistically significant.</p> <p>Conclusion</p> <p>Colorectal-cancer recurrence risks were not greatly different in patients who were randomly assigned to 65% nitrous oxide or nitrogen during surgery. Our results may not support avoiding nitrous oxide use to prevent recurrence of colorectal cancer.</p> <p>Implications Statement</p> <p>The risk of colorectal cancer recurrence was similar in patients who were randomly assigned to 65% nitrous oxide or nitrogen during colorectal surgery.</p> <p>Trial Registration</p> <p>Current Controlled Clinical Trials NCT00781352 <url>http://www.clinicaltrials.gov</url></p

Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats

<p>Abstract</p> <p>Background</p> <p>Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats.</p> <p>Methods</p> <p>Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of healing period, two titanium implants were bilaterally placed in the proximal metaphyses of tibia. The animals were randomly divided into a control group and biophysically-stimulated two test groups with five animals in each group. In the first test group, a pulsed electromagnetic field (PEMF) stimulation was administrated at a 0.2 mT 4 h/day, whereas the second group received low-magnitude high-frequency mechanical vibration (MECHVIB) at 50 Hz 14 min/day. Following completion of two week treatment period, all animals were sacrificed. Bone sites including implants were sectioned, removed <it>en bloc </it>and analyzed using a microCT unit. Relative bone volume and bone micro-structural parameters were evaluated for 144 μm wide peri-implant volume of interest (VOI).</p> <p>Results</p> <p>Mean relative bone volume in the peri-implant VOI around implants PEMF and MECHVIB was significantly higher than of those in control (<it>P </it>< .05). Differences in trabecular-thickness and -separation around implants in all groups were similar (<it>P </it>> .05) while the difference in trabecular-number among test and control groups was significant in all VOIs (<it>P </it>< .05).</p> <p>Conclusion</p> <p>Biophysical stimulation remarkably enhances bone volume around titanium implants placed in osteoporotic rats. Low-magnitude high-frequency MECHVIB is more effective than PEMF on bone healing in terms of relative bone volume.</p

Cervical squamous carcinoma cells are resistant to the combined action of tumor necrosis factor-α and histamine whereas normal keratinocytes undergo cytolysis

<p>Abstract</p> <p>Background</p> <p>Previous reports showed that mast cells can typically be found in the peritumoral stroma of cervix carcinomas as well as in many other cancers. Both histamine and TNF-α are potent preformed mast cell mediators and they can act simultaneously after release from mast cells. Thus, the effect of TNF-α and histamine on cervical carcinoma cell lines was studied.</p> <p>Methods and results</p> <p>TNF-α alone induced slight growth inhibition and cell cycle arrest at G0/G1 phase in SiHa cells, but increased their migration. Histamine alone had no effect on cells. In addition, TNF-α and histamine in combination showed no additional effect over that by TNF-α alone, although SiHa cells were even pretreated with a protein synthesis inhibitor. Furthermore, TNF-α-sensitive ME-180 carcinoma cells were also resistant to the combination effect of TNF-α and histamine. In comparison, TNF-α or histamine alone induced growth inhibition in a non-cytolytic manner in normal keratinocytes, an effect that was further enhanced to cell cytolysis when both mediators acted in combination. Keratinocytes displayed strong TNF receptor (TNFR) I and II immunoreactivity, whereas SiHa and ME-180 cells did not. Furthermore, cervix carcinoma specimens revealed TNF-α immunoreactivity in peritumoral cells and carcinoma cells. However, the immunoreactivity of both TNFRs was less intense in carcinoma cells than that in epithelial cells in cervical specimens with non-specific inflammatory changes.</p> <p>Conclusion</p> <p>SiHa and ME-180 cells are resistant to the cytolytic effect of TNF-α and histamine whereas normal keratinocytes undergo cytolysis, possibly due to the smaller amount of TNFRs in SiHa and ME-180 cells. In the cervix carcinoma, the malignant cells may resist this endogenous cytolytic action and TNF-α could even enhance carcinoma cell migration.</p