23 research outputs found

    On the giant deformation and ferroelectricity of guanidinium nitrate

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    The extraordinary properties of materials accompanying their phase transitions are exciting from the perspectives of scientific research and new applications. Most recently, Karothu et al.1 described guanidinium nitrate, [C(NH2)3]+[NO3]-, hereafter GN, as a ferroelectric semiconducting organic crystal with exceptional actuating properties. However, the ferroelectric and semiconducting properties of this hybrid organic-inorganic material were not confirmed by the experimental results, and the reproducibility of the large stroke associated with the first-order transition is questionable, because the GN crystals are inherently susceptible to the formation of defects. Besides, previous extensive studies on GN were not acknowledged

    Comparison of the characteristics of coronary interventions performed during day and night shifts in patients with acute myocardial infarction

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    Therapeutic percutaneous coronary intervention (PCI) is the treatment of choice in acute myocardial infarction (AMI). If optimally performed, PCI reduces myocardial injury and improves the likelihood of a positive clinical outcome. Therefore, the equal quality of PCI throughout both day and night shifts is of paramount importance. Our aim was to compare urgent diagnostic and therapeutic coronary interventions performed during day and night shifts. We retrospectively analyzed the medical records of 144 patients who underwent coronary angiography for AMI over six months in a tertiary referral center working in 24/7 mode. The patients’ characteristics, procedural data and the operator’s experience in interventional cardiology were compared according to the time of intervention during a day shift (8 a.m. until 8 p.m., group A, n = 106) and night shift (from 8 p.m. until 8 a.m. next day, group B, n = 36). The baseline characteristics of the subjects of groups A and B were similar, except for a higher proportion of AMI without persistent ST-segment elevation (NSTEMI) in patients who underwent coronary angiography during regular working hours compared to off-hours (58% vs. 34%, p < 0.05). The average time of diagnostic coronary angiography was longer by about 5 min during the day shift (28.5 ± 12.2 vs. 23.8 ± 8.9 min, p < 0.05), while other procedural data, including the arterial access route, the number of catheters needed and the contrast-medium volume, were similar. The use of additional diagnostic tools for coronary lesion assessment (intracoronary ultrasound or fractional flow reserve measurement) was almost twice as frequent during regular working hours (15% vs. 8%). Urgent therapeutic PCI on the culprit artery was performed in 79% and 89% of group A and B patients, respectively. The groups did not differ in procedural characteristics regarding the total interventional session, including both diagnostic angiography and therapeutic PCI, such as total procedure duration, fluoroscopy time, radiation dose, stenting technique and total stent length. Coronary thrombectomy or rotational atherectomy were more frequently used in group A (27% vs. 15%, p = 0.16). The percentage of doctors with the least experience in interventional cardiology was, albeit insignificantly, lower during day shifts (31% vs. 42%). In conclusion, the majority of clinical and periprocedural characteristics appeared to be independent of intervention time, except for a longer duration of diagnostic coronary angiography during daytime. This finding could probably result from a higher proportion of NSTEMI patients frequently requiring additional angiographic projections and special techniques to properly identify the infarct-related artery during the day shift. Whether a tendency of less frequent use of additional tools at off-hours may also be due to a lower percentage of NSTEMI interventions at night, or whether this can be linked to lower availability of experienced operators, remains to be validated in a large study. The latter possibility, if confirmed, might encourage public health authorities and healthcare organizers to improve off-hours cathlab staffing with experienced interventionalists. Finally, additional obligatory training in special diagnostic and therapeutic invasive techniques might be advisable for the least experienced operators scheduled to work night shifts

    Zalecenia dotycz膮ce post臋powania diagnostyczno-terapeutycznego u chorych na pierwotne nowotwory z艂o艣liwe ko艣ci

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    Mi臋saki ko艣ci u doros艂ych stanowi膮 heterogenn膮 grup臋 bardzo rzadkich nowotwor贸w pochodzenia mezenchymalnego (poni偶ej 0,5% nowotwor贸w z艂o艣liwych u doros艂ych). Prawid艂owe rozpoznanie i skuteczne leczenie skojarzone pierwotnych nowotwor贸w ko艣ci s膮 sum膮 wsp贸艂pracy radiolog贸w, chirurg贸w onkolog贸w i chirurg贸w ortoped贸w, onkolog贸w klinicznych, radioterapeut贸w, rehabilitant贸w, patolog贸w, specjalist贸w medycyny nuklearnej i biolog贸w molekularnych. Bezwzgl臋dnym warunkiem w diagnostyce i leczeniu pierwotnych nowotwor贸w z艂o艣liwych ko艣ci jest wielodyscyplinarna wsp贸艂praca wielospecjalistyczna w do艣wiadczonych o艣rodkach. Polepszenie diagnostyki mi臋sak贸w ko艣ci, wprowadzenie zasad terapii skojarzonej i post臋p technologiczny spowodowa艂y rozszerzenie wskaza艅 do stosowania operacji oszcz臋dzaj膮cych ko艅czyn臋 oraz poprawi艂y odleg艂e wyniki leczenia

    Recommendations for diagnostics and therapy of adult patients with malignant primary bone tumors

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    Bone sarcomas comprise a heterogenous group of rare mesenchymal tumors (less than 0.5% of malignant neoplasms in adults). From clinical point of view they can be divided into two main groups: spindle-cell sarcomas (osteosarcomas, majority of chondrosarcomas and less common subtypes) and small-cell sarcomas (mainly Ewing family of tumors). Correct diagnosis and effective therapy is performed by cooperation of radiologists, oncological and orthopedics surgeons, clinical oncologists, radiotherapists, rehabilitants, pathologists, nuclear medicine specialists and molecular biologists. The most important principle in diagnostics and therapy of primary malignant bone tumors is multidisciplinary work in experienced centers. Improvement of diagnostics, implementation of combined therapy and technological developments caused the increase of limb-sparing surgery indications and better long-term results of their treatment. Onkol. Prak. Klin. 2010; 6, 6: 355–369Mi臋saki ko艣ci u doros艂ych stanowi膮 heterogenn膮 grup臋 bardzo rzadkich nowotwor贸w pochodzenia mezenchymalnego (poni偶ej 0,5% nowotwor贸w z艂o艣liwych u doros艂ych). Pod wzgl臋dem klinicznym mi臋saki ko艣ci mo偶na podzieli膰 na mi臋saki wrzecionowatokom贸rkowe (obejmuj膮ce mi臋saki ko艣ciopochodne, wi臋kszo艣膰 chrz臋stniakomi臋sak贸w i inne rzadsze podtypy) oraz drobnokom贸rkowe (g艂贸wnie rodzina mi臋sak贸w Ewinga). Prawid艂owe rozpoznanie i skuteczne leczenie skojarzone pierwotnych nowotwor贸w ko艣ci s膮 sum膮 wsp贸艂pracy radiolog贸w, chirurg贸w onkolog贸w i chirurg贸w ortoped贸w, onkolog贸w klinicznych, radioterapeut贸w, rehabilitant贸w, patolog贸w, specjalist贸w medycyny nuklearnej i biolog贸w molekularnych. Bezwzgl臋dnym warunkiem w diagnostyce i leczeniu pierwotnych nowotwor贸w z艂o艣liwych ko艣ci jest wielodyscyplinarna wsp贸艂praca wielospecjalistyczna w do艣wiadczonych o艣rodkach. Polepszenie diagnostyki mi臋sak贸w ko艣ci, wprowadzenie zasad terapii skojarzonej i post臋p technologiczny spowodowa艂y rozszerzenie wskaza艅 do stosowania operacji oszcz臋dzaj膮cych ko艅czyn臋 oraz poprawi艂y odleg艂e wyniki leczenia. Onkol. Prak. Klin. 2010; 6, 6: 355–36

    Zasady post臋powania ortopedycznego w z艂o艣liwych nowotworach ko艣ci w wieku rozwojowym

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    Primary bone sarcomas are not frequent entities, but constitute important issue especially in pediatric population. Advances in chemotherapy and diagnostic modalities allowed limb saving resections of malignant bone tumors became leading surgical option. To be successful the treatment of primary bone tumors should be conducted in dedicated centers by experienced team of specialists. Nevertheless, the rules of such treatment should be known widely to improve diagnosis, medical care over oncologic patient and communication between specialists. In this review paper the authors present current rules of surgical approach to bony malignancies in children and adolescents.Z艂o艣liwe nowotwory uk艂adu ruchu s膮 rzadkimi, lecz istotnymi klinicznie chorobami, szczeg贸lnie w populacji pediatrycznej. Post臋py w skuteczno艣ci leczenia chemioterapeutycznego oraz poprawa mo偶liwo艣ci diagnostycznych spowodowa艂y zast膮pienie amputacji operacjami oszcz臋dzaj膮cymi ko艅czyny w chirurgicznym leczeniu guz贸w ko艣ci. Cho膰 leczenie tych chor贸b powinno by膰 prowadzone w specjalistycznych centrach, wiedza o zasadach post臋powania w z艂o艣liwych nowotworach ko艣ci powinna by膰 szeroko znana, dla poprawy procesu diagnostycznego, opieki nad pacjentem onkologicznym i u艂atwienia komunikacji mi臋dzy medycznymi profesjonalistami. W niniejszym przegl膮dzie autorzy przybli偶aj膮 zasady chirurgicznego post臋powania w z艂o艣liwych nowotworach uk艂adu ruchu u dzieci i m艂odzie偶y

    Photovoltaic Hybrid Perovskites under Pressure

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