The RM paraconsistent refutation system

The aim of this paper is to study the refutation system consisting of the refutation axiom p ∧ ¬p → q and the refutation rules: reverse substitution and reverse modus ponens (B/A, if A → B ∈ RM). It is shown that the refutation system is characteristic for the logic of the 3-element RM algebra

Implicational Logic, Relevance, and Refutability

The goal of this paper is to analyse Implicational Relevance Logic from the point of view of refutability. We also correct an inaccuracy in our paper “The RM paraconsistent refutation system” (DOI: http://dx.doi.org/10.12775/LLP.2009.005)

A system for proper multiple-conclusion entailment

The concept of proper multiple-conclusion entailment is introduced. For any sets X, Y of formulas, we say that Y is properly mc-entailed by X iff Y is mc-entailed by X, but no A ∈ Y is single-conclusion entailed by X. The concept has a natural interpretation in terms of question evocation. A sound and complete axiom system for the propositional case of proper mc-entailment is presented

Refutation Systems : An Overview and Some Applications to Philosophical Logics

Refutation systems are systems of formal, syntactic derivations, designed to derive the non-valid formulas or logical consequences of a given logic. Here we provide an overview with comprehensive references on the historical development of the theory of refutation systems and discuss some of their applications to philosophical logics

Rejection in Łukasiewicz's and Słupecki's Sense

The idea of rejection originated by Aristotle. The notion of rejection was introduced into formal logic by Łukasiewicz [20]. He applied it to complete syntactic characterization of deductive systems using an axiomatic method of rejection of propositions [22, 23]. The paper gives not only genesis, but also development and generalization of the notion of rejection. It also emphasizes the methodological approach to biaspectual axiomatic method of characterization of deductive systems as acceptance (asserted) systems and rejection (refutation) systems, introduced by Łukasiewicz and developed by his student Słupecki, the pioneers of the method, which becomes relevant in modern approaches to logic

Analysis of treatment efficacy and safety with leflunomide according to patients’ age and rheumatoid arthritis duration

Celem artykułu jest ocena skuteczności i bezpieczeństwa terapii leflunomidem w zależności od wieku chorych oraz czasu trwania reumatoidalnego zapalenia stawów (RZS). Bezpieczeństwo terapii leflunomidem przeanalizowano w grupie 261 pacjentów, porównując liczbę działań niepożądanych będących przyczyną przerwania terapii oraz liczbę działań niepożądanych leku niebędących przyczyną odstawienia leku, w zależności od wieku chorych, a także czasu trwania reumatoidalnego zapalenia stawów. W trakcie 6-miesięcznej obserwacji leczenie przerwało 27 pacjentów. Skuteczność terapii leflunomidem analizowano w grupie pozostałych 234 pacjentów na podstawie różnicy wartości wskaźnika DAS 28, ocenianego przed rozpoczęciem leczenia i po sześciu miesiącach terapii w zależności od wieku pacjentów. Wyniki potwierdziły skuteczność terapii leflunomidem we wszystkich grupach wiekowych chorych. Nie stwierdzono statystycznie istotnych różnic w skuteczności terapii w zależności od wieku pacjentów. Działania niepożądane leflunomidu wystąpiły u 47 chorych (18,8%), a u 23 (8,8%) były przyczyną przerwania terapii. Nie stwierdzono różnic statystycznie istotnych w występowaniu działań niepożądanych w zależności od wieku pacjentów oraz czasu trwania choroby podstawowej.Aim of the study: Evaluation of safety and therapeutic effectiveness of leflunomide according to age of the patients and duration of rheumatoid arthritis. Methods: Leflunomide therapy safety was analyzed in a group of 261 patients based on number of adverse effects responsible for treatment interruption and according to adverse effects number that allowed for continuing therapy. During six-month observation 27 patients interrupted therapy and in the group of remaining 234 persons leflunomide therapy efficacy was evaluated according to DAS-28 score. Results: Efficacy of leflunomide therapy was confirmed in every group according to patients age and no significant differences were observed between groups of patients with different age. Adverse leflunomide effects occurred in 47 (18.8%) patients and were the cause of therapy interruption in 23 (8.8%) cases. No significant differences in adverse leflunomide effects were observed to depend on patients age or rheumatoid arthritis period. Conclusions: (1) Patients’ age and period of rheumatoid arthritis do not influence leflunomide therapy safety. (2) Efficacy of leflunomide was confirmed in each group of patients. (3) Patients’ age does not influence leflunomide therapy outcome

Mechanical thrombectomy in acute stroke – Five years of experience in Poland

Objectives Mechanical thrombectomy (MT) is not reimbursed by the Polish public health system. We present a description of 5 years of experience with MT in acute stroke in Comprehensive Stroke Centers (CSCs) in Poland. Methods and results We retrospectively analyzed the results of a structured questionnaire from 23 out of 25 identified CSCs and 22 data sets that include 61 clinical, radiological and outcome measures. Results Most of the CSCs (74%) were founded at University Hospitals and most (65.2%) work round the clock. In 78.3% of them, the working teams are composed of neurologists and neuro-radiologists. All CSCs perform CT and angio-CT before MT. In total 586 patients were subjected to MT and data from 531 of them were analyzed. Mean time laps from stroke onset to groin puncture was 250±99min. 90.3% of the studied patients had MT within 6h from stroke onset; 59.3% of them were treated with IV rt-PA prior to MT; 15.1% had IA rt-PA during MT and 4.7% – emergent stenting of a large vessel. M1 of MCA was occluded in 47.8% of cases. The Solitaire device was used in 53% of cases. Successful recanalization (TICI2b–TICI3) was achieved in 64.6% of cases and 53.4% of patients did not experience hemorrhagic transformation. Clinical improvement on discharge was noticed in 53.7% of cases, futile recanalization – in 30.7%, mRS of 0–2 – in 31.4% and mRS of 6 in 22% of cases. Conclusion Our results can help harmonize standards for MT in Poland according to international guidelines