20 research outputs found

    Benign versus atypical meningiomas: Risk factors predicting recurrence

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    Objective The aim of the study is to determine which clinic, radiologic, and surgical characteristics of benign and atypical meningioma are associated with tumor progression. Methods 335 patients who underwent gross-total resection of intracranial benign and atypical meningiomas between 2000 and 2009 were followed during the period of at least 3 years. Clinical, radiological and surgical features possibly associated with progression-free survival and influencing tumor recurrence were assessed. Results 291 lesions were benign (WHO Grade I) and 44 were atypical (WHO Grade II). In the median follow-up period of 82 months 34 meningiomas recurred. The 3-, 5- and 10-year progression-free survival (PFS) rates for benign and atypical tumors were 99.7 and 81.4%, 97.5 and 69.7%, 87.5 and 69.7%, respectively. In a Kaplan鈥揗eier analysis subpial plane of surgical dissection (pial invasion) was associated with increased tumor progression both in benign (p=0.0084) and atypical cohort (p=0.0104), and bone involvement (p=0.0033) and peritumoral brain edema (p=0.0073) were associated with increased tumor progression only in atypical meningiomas. In a multivariate analysis pial invasion and WHO Grade II type were significantly associated with tumor recurrence. All recurrences in atypical meningioma group occurred within 4 years of the surgical resection. Conclusion Pial invasion is an important predictor of tumor recurrence in benign and atypical meningiomas. In atypical meningiomas bone involvement and large peritumoral brain edema are associated with increased tumor progression

    Safety and effectiveness of very-high-power, short-duration ablation in patients with atrial fibrillation: Preliminary results

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    Background: Pulmonary vein isolation (PVI) is at the forefront of rhythm control strategies in patients with atrial fibrillation (AF). A very-high-power, short-duration (vHPSD) catheter, QDot MicroTM (Biosense Webster) was designed to improve the effectiveness of AF ablation within a shorter procedure time. The aim of this study was to compare the effectiveness and safety of PVI ablation between this vHPSD ablation mode and conventional ablation-index-guided ablation (ThermoCool Smarttouch SF catheter). Methods: This single-center, retrospective, observational study enrolled 108 patients with AF, referred for catheter ablation between December 16, 2019 and December 3, 2021. In 54 procedures (mean age: 58.0 卤 12.3; 66.67% male), a QDot MicroTM catheter was used (vHPSD-group), and 54 patients (mean age: 57.2 卤 11.8; 70.37% male) were treated with a ThermoCool SmarttouchTM SF catheter (AI-group). The primary endpoint was freedom from AF 3 months after ablation. Results: Atrial fibrillation was found to recur in 14.81% of patients in the vHPSD-group and in 31.48% of patients in the AI-group (p = 0.07). There was no difference in treatment-emergent adverse events between the two groups (6.3% vs. 0%; p = 0.10). One severe adverse event (a cerebral vascular accident) was observed in the vHPSD-group. The mean dose of remifentanil was reported to be lower during QDot MicroTM catheter-based PVI (p < 0.01). The vHPSD-based PVI was associated with shorter radiofrequency application time (p < 0.001), fluoroscopy time (p < 0.0001), and total procedure time (p < 0.0001). Conclusions: This study suggests vHPSD ablation is safe, can reduce the dosage of analgesics during significantly shorter procedures and may enhance the success rate of catheter-based PVI

    Forecast and impact of electromobility development on the Polish Electric Power System

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    Thanks to the development of technology, the presence of electric vehicles (EVs) on the roads is no longer a purely theoretical issue. Also in Poland, electric cars are already visible on the streets, and charging stations (EVCS) are increasingly being installed near newly emerging buildings and housing estates. The article attempts to determine to what extent the use of electric cars will affect the demand for power and energy in the Polish electric power system (PEPS). The basis for PEPS modernization plans should be a detailed analysis of the technical adequacy of all its subsystems: generation, transmission and distribution, on the basis of which it will be possible to assess the potential impact of EVCS infrastructure operation on the Polish electric power system. This publication presents an example of such analysis for the distribution sub- sector, most exposed to potential negative interactions with the future, extensive infrastructure of EVCS

    Long-term outcomes and quality of life following implementation of dedicated mitral valve Heart Team decisions for patients with severe mitral valve regurgitation in tertiary cardiovascular care center

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    Background: This study was purposed to investigate which treatment strategy was associated with the most favourable prognosis for patients with severe mitral regurgitation (MR) following Heart Team (HT)-decisions implementation. Methods: In this retrospective study, long-term outcomes of patients with severe MR qualified after HT discussion to: optimal medical treatment (OMT) alone, OMT and MitraClip (MC) procedure or OMT and mitral valve replacement (MVR) were evaluated. The primary endpoint was defined as cardiovascular (CV) death and the secondary endpoints included all-cause mortality, myocardial infarctions (MI), strokes, hospitalizations for heart failure exacerbation and CV events during a mean (standard deviation [SD]) follow-up of 29 (15) months. Results: From 2016 to 2019, 176 HT meetings were held and a total of 157 participants (mean age [SD] = 71.0 [9.2], 63.7% male) with severe MR and completely implemented HT decisions (OMT, MC or MVR for 53, 58 and 46 patients, respectively) were included into final analysis. Comparing OMT, MC and MVR groups statistically significant differences between the implemented procedures and occurrence of primary and secondary endpoints with the most frequent in OMT-group were observed (p < 0.05). However, for interventional strategy MC was non-inferior to MVR for all endpoints (p > 0.05). General health status assessed at the end of follow-up were significantly the lowest for MVR, then for MC and the highest for OMT-group (p < 0.01). Conclusions: In the present study it was demonstrated that after careful HT evaluation of patients with severe MR at high risk of surgery, percutaneous strategy (MC) can be considered as equivalent to surgical treatment (MVR) with non-inferior outcomes

    Impact of wind turbines reliability models on the power generation system reliability

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    In this paper we describe the methodology of determining the reliability indices for power generating subsystem. We analyse then influence of the considered wind power plant reliability modelling on system reliability. The proposed reliability model of wind power plant is two-state model as compromise between calculation time and accuracy. We have found an empirical relationship between the power system reliability index LOLE (Loss of Load Expectation) and reserve capacity margin for a given wind share. This allowed us to estimate the required minimal reserve capacity margin for a given level of power system security and for a known structure of system installed capacity

    Assessment of the Accuracy of Determining the Angular Position of the Unmanned Bathymetric Surveying Vehicle Based on the Sea Horizon Image

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    The paper presents the results of research on assessing the accuracy of angular position measurement relative to the sea horizon using a camera mounted on an unmanned bathymetric surveying vehicle of the Unmanned Surface Vehicle (USV) or Unmanned Aerial Vehicle (UAV) type. The first part of the article presents the essence of the problem. The rules of taking the angular position of the vehicle into account in bathymetric surveys and the general concept of the two-camera tilt compensator were described. The second part presents a mathematical description of the meters characterizing a resolution and a mean error of measurements, made on the base of the horizon line image, recorded with an optical system with a Complementary Metal-Oxide Semiconductor (CMOS) matrix. The phenomenon of the horizon line curvature in the image projected onto the matrix that appears with the increase of the camera height has been characterized. The third part contains an example of a detailed analysis of selected cameras mounted on UAVs manufactured by DJI, carried out using the proposed meters. The obtained results including measurement resolutions of a single-pixel and mean errors of the horizon line slope measurement were presented in the form of many tables and charts with extensive comments. The final part presents the general conclusions from the performed research and a proposal of directions for their further development
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