155 research outputs found

    Primjena spektroskopskih metoda XRD, XPS i SEM u karakterizaciji kazeina devinog mlijeka koaguliranog djelovanjem kiselina i enzima te u određivanju utjecaja koagulacije na njegovu sposobnost emulgiranja

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    Casein, the main protein in milk, is a viable protein source for natural emulsifiers, which are frequently utilized in food emulsions. Camel milk casein powders obtained by acid and rennet coagulation were investigated and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). These methods gave extensive information regarding crystal structure, surface composition, and secondary and microstructures of the camel caseins, respectively. Therefrom new acknowledgements on morphology and surface composition have emerged, which is necessary to better understand functional characteristics such as emulsifying behaviour (i.e., emulsion’s stability over time and the oil droplet size). The O and C atomic proportions of camel casein surfaces generated by acidification were greater than those obtained through rennet-induced coagulation, whereas the percentage of N atomic was lower, according to XPS measurements. The oxygen to carbon (O/C) ratios on the surface of camel caseins produced by the two coagulation techniques were comparable. But, the enzymatic coagulation method yielded a high (N/C) ratio. ‎The findings suggested that rennet-induced coagulation might influence the C, O, and N components on the surface of camel milk caseins. Furthermore, SEM and XRD data revealed that acid aggregation affected casein micelle’s morphology, resulting in more β-sheet and smooth structures. Rennet camel caseins, on the other hand, have a porous colloidal surface. ‎A correlation between the casein surface composition and the emulsifying stability of the casein powders was observed, whereas the droplet size and stability of emulsions were strongly improved by the rennet-induced coagulation method.Kazein, glavni protein u mlijeku, održiv je izvor prirodnih emulgatora koji se često koriste u prehrambenim emulzijama. U ovom su istraživanju korištene metode rentgenske difrakcije (XRD), rentgenske fotoelektronske spektroskopije (XPS) i skenirajuće elektronske mikroskopije (SEM) u svrhu analize i karakterizacije kazeina u prahu dobivenog kiselinskom odnosno enzimskom koagulacijom devinog mlijeka. Spomenute instrumentalne metode rezultirale su opsežnim informacijama o kristalnoj strukturi, površinskom sastavu, odnosno sekundarnoj mikrostrukturi kazeina devinog mlijeka. Iz toga su proizišle su nove spoznaje o morfologiji i sastavu površine, a koje su potrebne za bolje razumijevanje funkcionalnih karakteristika poput sposobnosti emulgiranja i stabilnosti emulzije tijekom vremena i veličini kapljica ulja. Uzimajući u obzir mjerenja pomoću rentgenske difrakcije (XPS), udjeli atoma kisika i ugljika na površini kazeina koaguliranog djelovanjem kiseline bili su veći u usporedbi s kazeinom koji je dobiven enzimskom koagulacijom, dok je udio atoma dušika bio niži. Omjeri kisika i ugljika (O/C) na površini kazeina iz devinog mlijeka dobivenog na dva različita načina koagulacije bili su usporedivi. Međutim, metoda enzimske koagulacije rezultirala je visokim omjerom dušika i ugljika(N/C). Dobiveni rezultati impliciraju da bi enzimska koagulacija mogla utjecati na omjer ugljika, kisika i dušika na površini kazeina devinog mlijeka. Nadalje, rezultati dobiveni SEM i XRD analizom ukazuju da koagulacija kiselinom utječe na morfologiju micele kazeina, što rezultira s više β-nabranih ploča i glatkih struktura. S druge strane, enzimski koagulirani kazein devinog mlijeka pokazuje porozniju koloidnu površinu. Također je utvrđena i korelacija između sastava površine kazeina i sposobnosti emulgiranja kazeinskih prahova, dok su veličina kapljica i stabilnost emulzija značajno poboljšane enzimskom metodom koagulacije

    Experimental study of fire containment using water mist curtains in a reduced-scale deck of a ro-ro ship

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    Experiments have been conducted to evaluate the containment of smoke and heat using water mist curtains in a model setup of a ro-ro ship's cargo deck with a scale of 1:13, providing practical insights into the application of such fire protection systems in the cargo deck as well as valuable data for future numerical simulations. In this regard, the requirements of the international convention of Safety of Life at Sea (SOLAS) are studied for the side openings of so-called ‘open decks’ in comparison with ‘closed decks’, especially to examine the feasibility of using water mist curtains for creating isolated subdivisions in the ro-ro space as a fire management strategy. The water mist curtains are created with one or two rows of water mist nozzles at pressures ranging from 3 to 8 bar, while the source of smoke and heat is a liquid pool fire, and inert cargo items are used in some experiments. Correspondingly, the interaction between the water mist curtain(s) and the fire is evaluated in terms of its heat release rate, and the containment effect is quantified via measurements of smoke flow through the deck and through the windows, concentrations of gaseous species, as well as gas temperatures at various key locations. The study shows that water mist curtains have a strong effect on fire dynamics and smoke propagation, but containment is dependent on the configuration of side openings and the location of fire, among other important factors

    ASO author reflections: towards patient-tailored management of extremity soft tissue sarcoma

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    Orthopaedics, Trauma Surgery and Rehabilitatio

    Conocimiento y destrezas iniciales de los alumnos que acceden a cursos introductorios de física en 6 universidades iberoamericanas : cambio a lo largo del primer curso e incidencia en el éxito académi

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    Este trabajo forma parte de un estudio más extenso, financiado por la AECID, sobre la formación inicial de los alumnos que acceden a cursos de Física en varias universidades iberoamericanas, y de su influencia en el rendimiento académico en el primer curso. La muestra incluye alumnos de las universidades de Alcalá (España), Católica del Norte (Antofagasta, Chile), Santiago (Chile), San Luis (Argentina), San Juan (Argentina) y Tecnológico de Monterrey (México). En primer lugar se ilustra el grado alcanzado en la comprensión de conceptos físicos básicos, en destrezas relevantes para el estudio de la Física y en la capacidad de razonamiento científico. En la segunda parte se muestra como varía la comprensión de los conceptos en el primer año universitario y se analiza mediante un estudio correlacional la influencia de la formación inicial en el éxito académico

    Multimodality treatment of undifferentiated pleomorphic soft tissue sarcoma of the extremity (eUPS) in the elderly

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    Introduction: This subgroup analysis of undifferentiated pleomorphic soft tissue sarcoma of the extremity (eUPS) from the PERSARC collaborative group aimed to achieve a more personalized multimodality treatment approach for primary eUPS in elderly patients. Material and methods: A multicenter retrospective study including primary high-grade eUPS surgically treated with curative intent between 2000 and 2016. Overall survival (OS), local recurrence (LR) and distant metastasis (DM) curves were calculated by Kaplan Meier analysis. Cox proportional hazard models were used to determine the effect of radiotherapy. Results: From a total of 2511 patients with extremity soft tissue sarcoma (eSTS) of the PERSARC study collaborative; 703 patients with eUPS were included in this study. In elderly patients with eUPS 5-year OS, LR and DM were 35.4 (95%CI 29.3–42.8), 17.7 (95%CI 12.7–22.6) and 24.6 (95%CI 19.1–30.1). eUPS was significantly less treated with radiotherapy compared with other eSTS, especially in elderly patients. Patients with R1-R2 margins treated with radiotherapy had about half the risk of developing LR compared with patients treated without radiotherapy (HR = 0.454, p = 0.033). Conclusion: Elderly patients with eUPS were less often treated with radiotherapy and showed higher LR. Nowadays, given an increasing life expectancy in elderly patients, multimodality treatment should be considered

    The association of metastasis pattern and management of metastatic disease with oncological outcomes in patients with malignant peripheral nerve sheath tumors: a multicenter cohort study

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    Simple Summary:& nbsp;Around 40% of patients with MPNSTs develop distant metastasis (DM) within five years. Identification of MPNST patients more likely to develop DM and the identification of prognostic factors after DM diagnosis may guide clinical decision-making and may result in a better balance between quantity and quality of life. This study aimed to identify clinicopathologic and treatment-related factors associated with the development of DM and with overall survival (OS) after DM diagnosis. NF1, high grade, tumor size, triton and R2 resections were independent risk factors for the development of DM. This is the first study that reveals that NF1 status is also independently associated with worse survival after DM diagnosis with a median survival difference of more than 6 months between NF1 and no-NF1 patients.Purpose: This multicenter cohort study aimed to identify clinicopathologic and treatment-related factors associated with the development of distant metastasis (DM) and with overall survival (OS) after DM diagnosis in patients with malignant peripheral nerve sheath tumors (MPNST). Methods: All patients diagnosed with primary MPNST from 1988 to 2019 who were surgically treated for the primary tumor were included. Multivariable Cox regression analyses were performed to identify factors associated with DM and OS after DM diagnosis. Results: A total of 383 patients were included in this analysis, of which 150 developed metastatic disease. No differences in clinicopathologic characteristics and clinical outcome were found between patients with synchronous and metachronous DM. Neurofibromatosis type 1 (NF1), high grade, tumor size, triton and R2 resections were independent risk factors for the development of DM. NF1 and more than two metastasis sites were independently associated with worse OS after DM diagnosis. Metastasectomy, chemotherapy and the metastatic site category 'other' were associated with prolonged survival after DM diagnosis. Conclusions: This analysis provides important insights into clinicopathologic and treatment factors associated with outcomes in metastatic MPNST. Moreover, NF1-status is associated with a higher risk of DM; it is also independently associated with worse survival in metastatic MPNST.Orthopaedics, Trauma Surgery and Rehabilitatio

    Management of soft tissue sarcomas in extremities: variation in treatment recommendations and surveillance according to specialty and continent

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    Background This study aimed to provide an insight into clinical decision-making and surveillance strategy of sarcoma specialists for patients with primary soft tissue sarcoma of the extremities (eSTS). The secondary aim was to quantify the role of patient- and tumor-specific factors in the perioperative management. Methods Members of sarcoma societies were sent a Web-based 21-item survey about eSTS management. The survey concerned only primary resectable high-grade eSTS in adults. Results The study enrolled 396 respondents. The majority of the surgical specialists thought the evidence for perioperative chemotherapy (CTX) for high-grade eSTS was insufficient. Radiotherapy (RTX) was less frequently offered in Asia than in North America and Europe. The specialties and continents also differed regarding the importance of patient and tumor characteristics influencing RTX and CTX recommendation. For surveillance after initial treatment outpatient visits, chest computed tomography (CT) scans, and magnetic resonance images of the extremity were the methods primarily used. The specialists in North America preferred chest CT scan over chest x-ray, whereas those in Asia and Europe had no clear preference. Discussion Specialty and continent are important factors contributing to the variation in clinical practice, treatment recommendations, and surveillance of patients with primary resectable high-grade eSTS.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

    Survival analysis of 3 different age groups and prognostic factors among 402 patients with skeletal high-grade osteosarcoma: real world data from a single tertiary sarcoma center

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    Simple SummaryAge is one of many prognostic factors for overall survival in patients with skeletal osteosarcoma. This retrospective study provides an overview of survival in patients with high-grade osteosarcoma in different age groups. It shows prognostic variables for survival and local control among the overall cohort. In this study, in which 402 patients with skeletal high-grade osteosarcoma were included, poor survival was associated with increasing age. Age groups, tumor size, poor histopathological response, distant metastasis at presentation, and local recurrence were independent prognostic factors associated to overall survival and event-free survival. Differences in outcome among different age groups can be partially explained by patient characteristics and treatment characteristics.Age is a known prognostic factor for many sarcoma subtypes, however in the literature there are limited data on the different risk profiles of different age groups for osteosarcoma survival. This study aims to provide an overview of survival in patients with high-grade osteosarcoma in different age groups and prognostic variables for survival and local control among the entire cohort. In this single center retrospective cohort study, 402 patients with skeletal high-grade osteosarcoma were diagnosed and treated with curative intent between 1978 and 2017 at the Leiden University Medical Center (LUMC). Prognostic factors for survival were analyzed using a Cox proportional hazard model. In this study poor overall survival (OS) and event-free survival (EFS) were associated with increasing age. Age groups, tumor size, poor histopathological response, distant metastasis (DM) at presentation and local recurrence (LR) were important independent prognostic factors influencing OS and EFS. Differences in outcome among different age groups can be partially explained by patient and treatment characteristics.Experimentele farmacotherapi
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