Ricinusovo ulje kao obnovljiva sirovina za dobijanje poliuretanskih materijala

Traditionally, polyurethanes (PU) are manufactured by reacting isocyanates with petroleum-based polyols (polyether or polyester). Because oil resources are diminishing and are becoming expensive to produce, engineers and scientist have discovered new technologies to fabricate plastics from renewable resources. The goal of this work was to determine mechanical properties of polyurethanes synthesized from castor oil and different isocyantes: isophorone diisocyanate IPDI, 1,6-diisocyanatohexane (HDI) and aliphatic polycyclotrimer (HDIt). The samples were prepared by a one-step reactive process with stoichiometric balance of reactive groups. The catalysed synthesis was performed at normal pressure. It was estimated that a mechanical properties of prepared samples were strongly influenced by the isocyanate type.Tradicionalno se poliuretani (PU) dobijaju reagovanjem izocijanata sa poliolima (polietarski i poliestarski) koji se uobičajeno dobijaju iz nafte. Pošto se ti resursi smanjuju i postaju sve skuplji inženjeri i naučnici su razvili nove tehnologije za proizvodnju plastike iz obnovljivih sirovina. Cilj ovog rada je bio da se odrede mehanička svojstva poluretanskih materijala dobijenih jednostepenim reaktivnim procesom od ricinusovog ulja i različitih izocijanata: izoforon diizocijanata (IPDI), 1,6-diisocianatoheksana (HDI) i alifatičnog poliizocijanata ciklotrimera (HDIt) sa stehiometrijskim balansom reaktivnih grupa. Katalitička sinteza se odvijala na normalnom pritisku. Ustanovljeno je da su mehanička svojstva dobijenih materijala bila uslovljena tipom izocijanata

Impact of neoadjuvant therapy followed by laparoscopic radical gastrectomy with D2 lymph node dissection in Western population: A multi-institutional propensity score-matched study

Background and Objectives: In the setting of a minimally invasive approach, we aimed to compare short and long-term postoperative outcomes of patients treated with neoadjuvant therapy (NAT) + surgery or upfront surgery in Western population. Methods: All consecutive patients from six Italian and one Serbian center with locally advanced gastric cancer who had undergone laparoscopic gastrectomy with D2 lymph node dissection were selected between 2005 and 2019. After propensity score-matching, postoperative morbidity and oncologic outcomes were investigated. Results: After matching, 97 patients were allocated in each cohort with a mean age of 69.4 and 70.5 years. The two groups showed no difference in operative details except for a higher conversion rate in the NAT group (p = 0.038). The overall postoperative complications rate significantly differed between NAT + surgery (38.1%) and US (21.6%) group (p = 0.019). NAT was found to be related to a higher risk of postoperative morbidity in patients older than 60 years old (p = 0.013) but not in patients younger (p = 0.620). Conversely, no difference in overall survival (p = 0.41) and disease-free-survival (p = 0.34) was found between groups. Conclusions: NAT appears to be related to a higher postoperative complication rate and equivalent oncological outcomes when compared with surgery alone. However, poor short-term outcomes are more evident in patients over 60 years old receiving NAT

The impact of EAES Fellowship Programme:a five-year review and evaluation

Background: The European Association of Endoscopic Surgery (EAES) fellowship programme was established in 2014, allowing nine surgeons annually to obtain experience and skills in minimally invasive surgery (MIS) from specialist centres across the Europe and United States. It aligns with the strategic focus of EAES Education and Training Committee on enabling Learning Mobility opportunities. To assess the impact of the programme, a survey was conducted aiming to evaluate the experience and impact of the programme and receive feedback for improvements.Methods: A survey using a 5-point Likert scale was used to evaluate clinical, education and research experience. The impact on acquisition of new technical skills, change in clinical practice and ongoing collaboration with the host institute was assessed. The fellows selected between 2014 and 2018 were included. Ratings were analysed in percentage; thematic analysis was applied to the free-text feedbacks using qualitative analysis.Results: All the fellows had good access to observing in operating theatres and 70.6% were able to assist. 91.2% participated in educational activities and 23.5% were able to contribute through teaching. 44.1% participated in research activities and 41.2% became an author/co-author of a publication from the host. 97.1% of fellows stated that their operative competency had increased, 94.3% gained new surgical skills and 85.7% was able to introduce new techniques in their hospitals. 74.29% agreed that the clinical experience led to a change in their practices. The most commonly suggested improvements were setting realistic target in clinical and research areas, increasing fellowship duration, and maximising theatre assisting opportunities. Nevertheless, 100% of fellows would recommend the fellowship to their peers.Conclusion: EAES fellowship programme has shown a positive impact on acquiring and adopting new MIS techniques. To further refine the programme, an individualised approach should be adopted to set achievable learning objectives in clinical skills, education and research.</p

Preoperative rectal cancer staging with phased-array MR

<p>Abstract</p> <p>Background</p> <p>We retrospectively reviewed magnetic resonance (MR) images of 96 patients with diagnosis of rectal cancer to evaluate tumour stage (T stage), involvement of mesorectal fascia (MRF), and nodal metastasis (N stage).</p> <p>Our gold standard was histopathology.</p> <p>Methods</p> <p>All studies were performed with 1.5-T MR system (Symphony; Siemens Medical System, Erlangen, Germany) by using a phased-array coil. Our population was subdivided into two groups: the first one, formed by patients at T1-T2-T3, N0, M0 stage, whose underwent MR before surgery; the second group included patients at Tx N1 M0 and T3-T4 Nx M0 stage, whose underwent preoperative MR before neoadjuvant chemoradiation therapy and again 4-6 wks after the end of the treatment for the re-staging of disease.</p> <p>Our gold standard was histopathology.</p> <p>Results</p> <p>MR showed 81% overall agreement with histological findings for T and N stage prediction; for T stage, this rate increased up to 95% for pts of group I (48/96), while for group II (48/96) it decreased to 75%.</p> <p>Preoperative MR prediction of histologically involved MRF resulted very accurate (sensitivity 100%; specificity 100%) also after chemoradiation (sensitivity 100%; specificity 67%).</p> <p>Conclusions</p> <p>Phased-array MRI was able to clearly estimate the entire mesorectal fat and surrounding pelvic structures resulting the ideal technique for local preoperative rectal cancer staging.</p

Large negative lymph nodes – a surrogate for immune activation in rectal cancer patients?

Aim: The size of regional, tumor draining lymph nodes without metastasis (LNneg) found in rectal cancer resection specimens varies and seems to be related to patient survival. Yet, the histopathological features influencing LNneg size in rectal cancer have not been studied in detail. Our pilot study focused on investigating the relationship between lymph node (LN) size and LNneg microarchitecture in rectal cancer (RC) resection specimens. Method: In this retrospective cohort study, resection specimens from 146 RC patients, treated with either surgery alone (n = 29) or neoadjuvant therapy followed by resection (n = 117), were included in the study. Histology of LNnegs was reviewed to establish number of lymphoid follicles and presence of intranodal fat. Longest long axis and area of each LN were measured digitally. Results: 1830 LNnegs were measured. The microarchitecture was analyzed in a subset of 680 LNnegs. 153 (22.5 %) LNnegs contained intranodal fat. After neoadjuvant treatment, presence of intranodal fat was related to smaller LNneg area (median (range) area of LNneg without intranodal fat: 4.51 mm2 (0.15-46.89 mm2), with intranodal fat: 3.46 mm2 (0.12-27.22 mm2), p = 0.048). A higher number of lymphoid follicles was related to a larger LNneg area in both patient groups (p < 0.001). Conclusion: Our pilot data suggest that in rectal cancer the presence of large regional LNnegs may reflect increased immune activation due to tumor related antigens. Further studies are warranted to investigate whether histologically visible microarchitectural features of LNnegs such as lymphoid follicles translate to particular features in radiological images and hence could potentially help to identify LNneg with more certainty at the time of pre-treatment disease staging

Local staging of rectal cancer: the current role of MRI

With the advent of powerful gradient coil systems and high-resolution surface coils, magnetic resonance imaging (MRI) has recently extended its role in the staging of rectal cancer. MRI is superior to endorectal ultrasound, the most widely used staging modality in patients with rectal tumors, in that it visualizes not only the intestinal wall but also the surrounding pelvic anatomy. The crucial advantage of MRI is not that it enables exact T-staging but precise evaluation of the topographic relationship of a tumor to the mesorectal fascia. This fascia is the most important anatomic landmark for the feasibility of total mesorectal excision, which has evolved into the standard operative procedure for the resection of cancer located in the middle or lower third of the rectum. MRI is currently the only imaging modality that is highly accurate in predicting whether or not it is likely that a tumor-free margin can be achieved and thus provides important information for planning of an effective therapeutic strategy, especially in patients with advanced rectal cancer