Degradability of Polyurethanes and Their Blends with Polylactide, Chitosan and Starch

One of the methods of making traditional polymers more environmentally friendly is to modify them with natural materials or their biodegradable, synthetic equivalents. It was assumed that blends with polylactide (PLA), polysaccharides: chitosan (Ch) and starch (St) of branched polyurethane (PUR) based on synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) would degrade faster in the processes of hydrolysis and oxidation than pure PUR. For the sake of simplicity in the publication, all three modifiers: commercial PLA, Ch created by chemical modification of chitin and St are called bioadditives. The samples were incubated in a hydrolytic and oxidizing environment for 36 weeks and 11 weeks, respectively. The degradation process was assessed by observation of the chemical structure as well as the change in the mass of the samples, their molecular weight, surface morphology and thermal properties. It was found that the PUR samples with the highest amount of R,S-PHB and the lowest amount of polycaprolactone triol (PCLtriol) were degraded the most. Moreover, blending with St had the greatest impact on the susceptibility to degradation of PUR. However, the rate of weight loss of the samples was low, and after 36 weeks of incubation in the hydrolytic solution, it did not exceed 7% by weight. The weight loss of Ch and PLA blends was even smaller. However, a significant reduction in molecular weight, changes in morphology and changes in thermal properties indicated that the degradation of the samples should occur quickly after this time. Therefore, when using these polyurethanes and their blends, it should be taken into account that they should decompose slowly in their initial life. In summary, this process can be modified by changing the amount of R,S-PHB, the degree of cross-linking, and the type and amount of second blend component added (bioadditives).This research was founded by the National Science Center Poland Miniatura 2 project no. 2018/02/X/ST5/02005 and partially by the UMG research project no. WZNJ/2021/PZ/02

HLC Project 2018 : Jagiellonian University excavations in southern Jordan

A complex picture of the prehistory in southern Jordanian emerges from the excavations of the Jagiellonian University team, which carried out in 2018 its second season of excavation at the sites of Munqata’a and Faysaliyya, even as analyses of the previous season’s nds were underway. Human communities living here between the Neolithic and early Bronze Age practiced both sedentary and mobile lifestyles. The changing landscape around them, caused by natural erosion processes and periodical climate changes, is also factored into the interpretation of the explored relic

Romantic Name for a Deadly Condition: Kissing Aneurysms of the Pericallosal Artery – A Case Report

Background: Kissing aneurysms are two independent but adjacent aneurysms protruding from two contralateral arterial locations. This report describes a successfully treated case of kissing aneurysms at the Department of Neurosurgery, Medical University of Gdansk. Case: A 45-year-old asymptomatic woman was diagnosed with unruptured bilateral aneurysms located in the pericallosal-callosomarginal division. Her medical history included a previous intracranial aneurysm and arterial hypertension. The patient underwent a successful treatment by surgical clipping and was discharged in good condition; neither disability nor neurologic deficit was noticed upon discharge. Surgical wound healing was complicated by an infection and resulted in a reoperation for the patient. Conclusion: The etiology of kissing aneurysms is still unknown and the best treatment method stills remains unclear. Thus, every case has to be carefully and individually assessed by an interdisciplinaryteam. As a result, patient transfer to an experienced neurosurgical center could be beneficial

Del Nido cardioplegia versus other contemporary solutions for myocardial protection – a literature review

Myocardial protection is one of the most important factors ensuring patient safety during cardiac surgery with the application of cardiopulmonary bypass. Infusion of cardioplegic solution into the coronary circulation protects the heart and provides a standstill operating field for the surgeon. Cold blood cardioplegia and crystalloid cardioplegia are the two main types of solutions with a long history of use and a large amount of research proving their efficacy and safety. Relatively new del Nido cardioplegia seems to be an interesting alternative. We reviewed the literature comparing del Nido cardioplegia with two other types of cardioplegic solutions. We took into consideration many different clinical and biochemical aspects may indicate the quality of cardioprotection

HLC Project 2017 : Jagiellonian University excavations in southern Jordan

The HLC (Heritage-Landscape-Community) archaeological metaproject, carried out since 2016 by the Jagiellonian University in cooperation with the Department of Antiquities, Ministry of Antiquities and Tourism, Hashemite Kingdom of Jordan, targets the archaeological heritage of southern Jordan (Tafila region), focusing currently on remains of the Early Bronze Age and earlier cultures that were found in the region. The project has already identified and verified several previously undocumented or poorly documented sites. Its main objective is to establish chronological phasing of human activity in this microregion, particularly during the Early Bronze Age and to assess the scale and nature of human presence in that period. Two sites, Faysaliyya and Munqata’a, were excavated within the frame of the project. The article presents the preliminary results of this work. An important side issue is the protection of Jordanian heritage in the Tafila region through the identification of natural and human agents that may damage or destroy it.The HLC (Heritage-Landscape-Community) archaeological metaproject, carried out since 2016 by the Jagiellonian University in cooperation with the Department of Antiquities, Ministry of Antiquities and Tourism, Hashemite Kingdom of Jordan, targets the archaeological heritage of southern Jordan (Tafila region), focusing currently on remains of the Early Bronze Age and earlier cultures that were found in the region. The project has already identified and verified several previously undocumented or poorly documented sites. Its main objective is to establish chronological phasing of human activity in this microregion, particularly during the Early Bronze Age, and to assess the scale and nature of human presence in that period. Two sites, Faysaliyya and Munqata’a, were excavated within the frame of the project. The article presents the preliminary results of this work. An important side issue is the protection of Jordanian heritage in the Tafila region through the identification of natural and human agents that may damage or destroy it

The Acheulean handaxes from Faysaliyya (Shawbak directorate, southwestern Jordan), 2017 season

W artykule zaprezentowano kolekcję pięściaków zebranych z powierzchni stanowiska Faysaliyya w południowo-zachodniej Jordanii. Od 2017 roku stanowisko jest badane przez polską ekspedycję z Instytutu Archeologii Uniwersytetu Jagiellońskiego w Krakowie w ramach realizacji projektu badawczego HLC Project. W trakcie prac badawczych (wykopaliskowych i powierzchniowych) w 2017 roku odkryto bardzo liczne materiały krzemienne o różnej chronologii począwszy od dolnego paleolitu aż po neolit/epokę brązu. Wśród zabytków o najstarszej chronologii na szczególną uwagę zasługuję powierzchniowy zbiór 23 pięściaków aszelskich. Zostały one zebrane we wschodniej części stanowiska, jednak nie tworzyły żadnej koncentracji i najprawdopodobniej ich obecność na powierzchni gruntu była wynikiem intensywnych procesów fluwialnych. Pięściaki przedstawione w niniejszym artykule zostały sklasyfikowane według zasad typologii F. Bordesa. W omawianym zbiorze najliczniejsze są pięściaki migdałowate (9 okazów). Wśród pozostałych wyróżniono: 4 podsercowate, 3 dyskoidalne, 2 sercowate, 2 podtrójkątne i 1 ficron mikocki. W dwóch przypadkach jednoznaczne zaklasyfikowanie zabytków było niemożliwe. Wszystkie analizowane pięściaki zostały wykonane z lokalnego, brązowo-beżowego krzemienia o stosunkowo dobrej jakości. Ich charakterystyczną cechą jest stan zachowania – patyna i zwietrzenie typowe dla zabytków krzemiennych, poddanych długotrwałemu oddziaływaniu suchego środowiska pustynnego. Ponadto noszą one widoczne ślady transportu wodnego. Poza jednym zabytkiem o cechach „prymitywnych”, wszystkie cechują się starannymi odbiciami bifacjalnymi. Z powodu licznych podepozycyjnych uszkodzeń rekonstrukcja poszczególnych faz formowania pięściaków jest trudna. Widoczne na zabytkach odbicia bifacjalnie mogą być przypisane do dwóch pierwszych z nich, natomiast ostatnia związana z ostatecznym formowaniem krawędzi najprawdopodobniej jest niewidoczna z powodu licznych obtłuczeń. Pomimo, że zaprezentowana kolekcja pięściaków ze stanowiska Faysaliyya z pewnością nie jest inwentarzem homogenicznym i najprawdopodobniej zostały one przetransportowane z pierwotnego miejsca zlegania przez procesy fluwialne, ich analiza dostarczyła kilku interesujących obserwacji. Wszystkie zostały wykonane z tego samego surowca kamiennego i odznaczają się podobnym stanem zachowania. Na podstawie ich cech morfologicznych można dość ogólnie datować je na środową lub późną fazę rozwoju kultury aszelskiej. Za późnoaszelską chronologią omawianej kolekcji przemawia wykonanie wszystkich zabytków z krzemienia oraz brak rozłupców i wczesnych typów pięściaków. Należy również wspomnieć, że zaprezentowana kolekcja jest podobna do innych późnoaszelskich inwentarzy z pięściakami z terenu południowo-zachodniej Jordanii (Fjaje, Wadi Faynan, Wadi Qalkha), a także południowego Izraela (Nahal Zihor).This paper presents the inventory of 23 Lower Paleolithic handaxes surface collected at the Faysaliyya archaeological site in 2017. The purpose of the paper is to inform about a new collection of handaxes found in the highland region of southern Jordan, provide its detailed description, and draw some preliminary conclusions which may be useful for further studies on numerous lithics materials from Faysaliyya. The site is located in southwestern Jordan, in the northern part of the geographical and historical region of Edom, the Edom Highland. It was discovered during rescue surveys in 2016 and has been exacavated since 2017 by a Polish team from the Institute of Archaeology of the Jagiellonian University within the framework of the HLC Project. The presented handaxes were made of relatively high quality local flints. They all are characterized by a state of preservation typical for lithic artefacts obtained from a desert environment (patina, weathering). Moreover, most of them bear traces of abrasion and damages, which suggests that they could have been brought to Faysaliyya by fluvial transportation. The handaxes have been classified according to F. Bordes’ typology. They mostly include amygdaloids and sub-cordiforms but several coridiforms, discoidals, sub-triangulars, and a single Miqocian ficron have been distinguished as well. Two artefacts have been classified as miscellaneous forms. In a very few cases, traces of reutilization as flake cores, or some kinds of modification/rejuvenation are visible on the handaxes. Due to their finding context, the group of handaxes presented in this paper cannot be considered as a homogenous assemblage and may consist of artefacts of various chronology. Generally, the analysed handaxes reveal features which are typical of the Late Acheulean, but it cannot be excluded that some of them may be dated to the Middle Acheulean (alternatively Large Flake Acheulean). Thus, the presented inventory seems to be similar to others surface collections of handaxes from southwestern Jordan, such as Fjaje, Wadi Faynan or Wadi Qalkha

Del Nido cardioplegia versus other contemporary solutions for myocardial protection – a literature review

Myocardial protection is one of the most important factors ensuring patient safety during cardiac surgery with the application of cardiopulmonary bypass. Infusion of cardioplegic solution into the coronary circulation protects the heart and provides a standstill operating field for the surgeon. Cold blood cardioplegia and crystalloid cardioplegia are the two main types of solutions with a long history of use and a large amount of research proving their eficacy and safety. Relatively new del Nido cardioplegia seems to be an interesting alternative. We reviewed the literature comparing del Nido cardioplegia with two other types of cardioplegic solutions. We took into consideration many diefrent clinical and biochemical aspects may indicate the quality of cardioprotection. Brzeska B, Karolak W, Żelechowski P, Łoś A, Ulatowski N, Pawlaczyk R. Del Nido cardioplegia versus other contemporary solutions for myocardial protection - a literature review. Eur J Transl Clin Med. 2023;6(1):41-57

Susceptibility to Degradation in Soil of Branched Polyesterurethane Blends with Polylactide and Starch

A very important method of reducing the amount of polymer waste in the environment is the introduction to the market of polymers susceptible to degradation under the influence of environmental factors. This paper presents the results of testing the susceptibility to degradation in soil of branched polyesterurethane (PUR) based on poly([R,S]-3-hydroxybutyrate) (R,S-PHB), modified with poly([D,L]-lactide) (PLA) and starch (St). Weight losses of samples and changes in surface morphology (SEM, OM and contact angle system) with simultaneously only slight changes in molecular weight (GPC), chemical structure (FTIR and 1HNMR) and thermal properties (DSC) indicate that these materials are subject to enzymatic degradation caused by the presence of microorganisms in the soil. Chemical modification of branched polyesterurethanes with R,S-PHB and their physical blending with small amounts of PLA and St resulted in a slow but progressive degradation of the samples