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Effects of reoperation timing on survival among recurrent glioblastoma patients: A retrospective multicentric descriptive study
Get PDFGlioblastoma inevitably recurs, but no standard regimen has been established for treating this recurrent disease. Several reports claim that reoperative surgery can improve survival, but the effects of reoperation timing on survival have rarely been investigated. We, therefore, evaluated the relationship between reoperation timing and survival in recurrent GBM. A consecutive cohort of unselected patients (real-world data) from three neuro-oncology cancer centers was analyzed (a total of 109 patients). All patients underwent initial maximal safe resection followed by treatment according to the Stupp protocol. Those meeting the following criteria during progression were indicated for reoperation and were further analyzed in this study: (1) The tumor volume increased by >20-30% or a tumor was rediscovered after radiological disappearance; (2) The patient's clinical status was satisfactory (KS = 70% and PS WHO = gr. 2); (3) The tumor was localized without multifocality; (4) The minimum expected tumor volume reduction was above 80%. A univariate Cox regression analysis of postsurgical survival (PSS) revealed a statistically significant effect of reoperation on PSS from a threshold of 16 months after the first surgery. Cox regression models that stratified the Karnofsky score with age adjustment confirmed a statistically significant improvement in PSS for time-to-progression (TTP) thresholds of 22 and 24 months. The patient groups exhibiting the first recurrence at 22 and 24 months had better survival rates than those exhibiting earlier recurrences. For the 22-month group, the HR was 0.5 with a 95% CI of (0.27, 0.96) and a p-value of 0.036. For the 24-month group, the HR was 0.5 with a 95% CI of (0.25, 0.96) and a p-value of 0.039. Patients with the longest survival were also the best candidates for repeated surgery. Later recurrence of glioblastoma was associated with higher survival rates after reoperation.65269705; 00159816; 00209805; Ministerstvo Zdravotnictví Ceské Republiky, MZCR: 00098892, NU20-03-00148, NU21-03-00195Ministry of Health of the Czech Republic [NU21-03-00195, NU20-03-00148, 00098892, 00209805, 65269705, 00159816
An examination of complex fractional order physical phenomena in IOPD controller design
Get PDFThis research focuses on the fractional complex order plant (FCOP). The significant contribution is the role of complex plant models in system stability and robustness and associated physical phenomena. A general transfer function is studied in the paper. Other plant models may be built with this structure since the FCOP is a general mathematical form covering integer order plant (IOP) and fractional order plant (FOP). Using the equations produced with the proposed technique and the recommended integer order proportional derivative (IOPD controller, physical changes in integer, fractional and complex coefficients, and orders are observed within this paper. Analysis of the plant controlled with an IOPD controller is done by applying an integrator to reveal the differences. The effects of the parameters are discussed together with the visuals, supported by simulations. The aim is to tune the controller parameters to achieve the phase and specifications as the researcher desired. It is observed that the integrator greatly takes part in reducing the steady-state error. The IOP with the integrator showed the lowest steady-state error, and also, the settling and overshoot time were enhanced. Increase in the phase margin also caused an increase in the phase crossover frequency. It is also observed that the fractional order affected the phase crossover frequency comparing with the IOP, and the complex order modification also had an effect comparing to the fractional order version. The complex order of the system is considered with its conjugate components in the imaginary part thus, the results are found separately for each case
Exploring attitudes towards adult learning and education: group patterns among participants and non-participants
Get PDFBased on contemporary theories of participation, attitudes toward Adult Learning and Education (ALE) are considered crucial determinants predicting adults' involvement in further education. However, their investigation is usually not empirically systematic and theoretically grounded. For this reason, the article analyses attitudes to ALE based on a novel approach - the triadic model of culture by Lizardo. We present a conceptualisation of attitudes to ALE, inspired by this model, distinguishing between (1) public, (2) personal declarative, and (3) personal non-declarative dimensions of attitudes. Based on that, we show the empirical results of a representative survey among adult population (25-69 years) in the Czech Republic (n = 1200). In this regard, we map differences in attitudes between participants and nonparticipants and results of a cluster analysis to identify main groups with similar attitudes toward ALE. Our findings confirm the employed theoretical concept and identify significant differences between participants and nonparticipants. Beyond that, we identify four clusters of adults with distinctive attitudes of which all contain a different mixture of participants and nonparticipants: (1) adults with positive attitudes; (2) adults with personal obligations toward ALE; (3) adults who see the public value of ALE; (4) adults with negative attitudes
Influence of PMMA brushes grafted from GO on rheological properties of PMMA/SAN immiscible blend in shear and elongation flow
Get PDFIn real technological processes, both shear and elongational flow is present. The material properties may differ significantly under both types of flow. Hence, they both define the final morphology and thus properties of the materials. In this work, the morphology of immiscible blends containing polymer hybrid particles was related to extensional rheological properties for the first time. The effect of various lengths of polymer brushes grafted from graphene oxide particles (GO) surface was investigated. As a polymer matrix the immiscible blend of poly(methyl methacrylate)/styrene-co-acrylonitrile (PMMA/SAN) was used. Thus the poly(methyl methacrylate) (PMMA) brushes grafted from GO (GO-g-PMMA) with various number average molar masses (Mn) of PMMA brushes with respect to chain entanglement limit of freely dispersed PMMA were prepared. The extensional rheological properties were affected by Mn of PMMA brushes, while the rheological properties in shear were unchanged. Transmission electron microscopy revealed the compatibilization effect for short densely grafted brushes with Mn of 10,300 g/mol, as smaller domains were observed. On the contrary, the higher Mn PMMA brushes facilitated coalescence. With increasing length of brushes, the elongational viscosity at low elongation rates (∼ 0.1 s−1) was not sufficient enough to cause fiber breakup and thus elongated domains were formed.665778; Slovenská Akadémia Vied, SAV: 313021T081; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2022/003; Narodowe Centrum Nauki, NCN: UMO-2016/23/P/ST5/02131; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA: 2/0137/23; European Regional Development Fund, ERDF: APVV-19-0338National Science Centre, Poland [UMO-2016/23/P/ST5/02131]; European Union [665778]; Ministry of Education, Youth and Sports of the Czech republic-DKRVO [RP/CPS/2022/003]; Integrated Infrastructure Operational Program - ERDF [313021T081]; [APVV-19-0338]; [VEGA 2/0137/23
Combination of chemotherapy and mild hyperthermia using targeted nanoparticles: A potential treatment modality for breast cancer
Get PDFDespite the clinical benefits that chemotherapeutics has had on the treatment of breast cancer, drug resistance remains one of the main obstacles to curative cancer therapy. Nanomedicines allow therapeutics to be more targeted and effective, resulting in enhanced treatment success, reduced side effects, and the possibility of minimising drug resistance by the co-delivery of therapeutic agents. Porous silicon nanoparticles (pSiNPs) have been established as efficient vectors for drug delivery. Their high surface area makes them an ideal carrier for the administration of multiple therapeutics, providing the means to apply multiple attacks to the tumour. Moreover, immobilising targeting ligands on the pSiNP surface helps direct them selectively to cancer cells, thereby reducing harm to normal tissues. Here, we engineered breast cancer-targeted pSiNPs co-loaded with an anticancer drug and gold nanoclusters (AuNCs). AuNCs have the capacity to induce hyperthermia when exposed to a radiofrequency field. Using monolayer and 3D cell cultures, we demonstrate that the cell-killing efficacy of combined hyperthermia and chemotherapy via targeted pSiNPs is 1.5-fold higher than applying monotherapy and 3.5-fold higher compared to using a nontargeted system with combined therapeutics. The results not only demonstrate targeted pSiNPs as a successful nanocarrier for combination therapy but also confirm it as a versatile platform with the potential to be used for personalised medicine.National Health and Medical Research Council, NHMRC: GNT1112432National Health and Medical Research Council (NHMRC) of Australia [GNT1112432
Adaptation of QGIS tools in high school geography education
Get PDFIn the last decades, geography teachers have been trying to figure out how to adopt GIS (Geographic Information Systems) tools for their high school classes. Predominantly, teachers have come to use commercial versions. Lately, it has been QGIS getting more attention, especially in environments where teachers do not have access to sufficient funding. Nevertheless, there is a lack of ample research results and available teaching materials for geography teachers that want to give QGIS in their lessons a go. This paper presents our attempt to bridge this gap. We have set several goals in our search for the possibilities of adopting QGIS tools for high school geography lessons. The main one was to learn about the strategies that students have when they are learning about QGIS. Furthermore, we wanted to know what knowledge the students would demonstrate after attending a short course on QGIS basics and if their learning strategies during the lectures would impact their results. To find out, we created a set of 10 lessons and tested most of them on students from a high school in Brno, Czech Republic. The results of two pilot studies show that our research has not ended and that further investigation needs to be made about the circumstances that can affect a successful adaptation of QGIS tools in high school geography education
The comparison of the effect of flour particle size and content of damaged starch on rice and buckwheat slurry, dough, and bread characteristics
Get PDFThe effect of botanical origin, the flour particle size, and the content of damaged starch on flour pasting properties, dough behavior during a uniaxial deformation test, and bread characteristics were evaluated on rice and buckwheat flours. The rice flour with a median particle size D(0.5) of 60.2, 70.6, 106.8, and 189.4 & mu;m, and buckwheat flour with a D(0.5) of 56.4, 68.4, and 95.8 & mu;m were prepared using the same milling technology. The botanical origin of the flours was the strongest factor influencing the flour pasting properties, stress accumulated in dough during the uniaxial deformation test, loaf characteristics, texture, and sensory characteristics of breads. The flour particle size significantly influenced mainly the flour pasting properties. The effect of the content of damaged starch was the weakest among the studied factors. The flour particle size and the content of damaged starch were closely related. The flour botanical origin was the strongest factor; therefore, it seems not to be possible to predict the bread-baking potential of gluten-free flours based on the results obtained for flour of a different botanical origin. More research on flours from different plants prepared by the same milling process is required to support this hypothesis.Univerzita Tomáše Bati ve Zlíně, (IGA/FT/2023/010
The relations between Czech undergraduates' motivation and emotion in self-regulated learning, learning engagement, and academic success in blended course designs: Consistency between theory-driven and data-driven approaches
Get PDFCombining theory-driven and data-driven approaches, this study used both self-reported and observational measures to examine: (1) the joint contributions of students’ self-reported undergraduates’ motivation and emotion in their self-regulated learning, their observed online learning interactions, and their academic success in blended course designs; and (2) the extent to which the self-reported and observational measures were consistent with each other. The participants in the study were 54 social sciences undergraduates in the Czech Republic. The participants’ self-reported self-efficacy, intrinsic goals, and anxiety were assessed using a Czech version of three scales from the Motivated Strategies for Learning Questionnaire. Their online engagement was represented by students’ observed frequency of interactions with the six online learning activities recorded in the learning management system. The results of a hierarchical regression analysis showed that the self-reported and observational measures together could explain 71% of variance in academic success, significantly improving explanatory power over using self-reported measures alone. Departing from the theory-driven approach, students were clustered as better and poorer self-regulated learners by their self-reports, and one-way ANOVAs showed that better self-regulated learners had significantly more frequent online interactions with four out of six online learning activities and better final exam results. Departing from the data-driven approach, students were clustered as higher and lower online-engaged learners by the observed frequency of their interaction with online learning activities. One-way ANOVAs showed that higher online-engaged learners also reported having higher self-efficacy and lower anxiety. Furthermore, the strong association between the students’ profiles in both self-reported measures and observational measures in cross-tabulation analyses showed that the majority of better self-regulated learners by self-reporting also had higher online engagement by observation, whereas the majority of poorer self-regulated learners by self-reporting were lower online-engaged learners, demonstrating consistency between theory-driven and data-driven approaches. Copyright © 2022 Han, Vaculíková and Juklová.CZ.02.2.69/0.0/0.0/18_053/0017841; Univerzita Hradec Králové, UHK: 210
From undistracted to instant reading and back: Prototyping a new digital library service
No full textNew technologies and digital services influence the current forms of reading, and public libraries respond to these possibilities by offering new services based mainly on ebooks. The constraints resulting from the recent waves of the COVID-19 pandemic have reinforced this trend. This work introduces the development process of new library services based on open web books experimentally developed at Masaryk University and the Municipal Library of Prague. Our initial research focused on people's behavior when reading a book in a browser, on elements of user interface interactions, and the overall context of reading on different types of devices, especially mobile. Through a Research through Design approach, qualitative inquiry, and prototyping, we have identified patterns in reading behavior and library users' needs, to which we have responded by designing a new service. We converted the new service concept into interactive prototypes in the Figma tool, which we further tested and iterated. The research supports reading in the digital world and brings new information about reading behavior in the age of instant digital services.Czech Technology Agency [TL04000391
The effect of apparent cross-link density on cut and chip wear in natural rubber
No full textNatural rubber is a polymer that, by inducing crystallization at a certain level of stress, contributes significantly to reducing cut and chip (CC) damage to rubber articles when exposed to harsh conditions. This unique property is dependent on several factors, including the processing conditions, the cross-linking system and the type of additives used, resulting in varying apparent cross-link density (CLD) of the cross-linked CB filled rubber. Therefore, this work focuses on the systematic investigation of CC phenomena as a function of CLDs represented by conventional (CV), semi-efficient (SEV) and efficient (EV) cross-linking systems. Rubber samples based on different cross-linking systems were prepared by varying the concentration of the accelerator N-tert-butylbenzothiazolesulfonamide (TBBS) at a constant concentration of 2.5 phr sulfur as a cross-linking agent. The different CLDs were achieved by different concentration ratios (A/S) between accelerator (A) and sulfur (S), using A/S = 0.1, 0.3, 0.6 for the CV system, A/S = 0.7, 1.0, 1.5, 2.0, 2.5 for the SEV system and A/S = 3.0 for the EV system. First, the basic mechanical behaviour was presented as a function of CLD, with the optimal behaviour found in the range of 181-241 mu mol x cm(-3). The CC resistance is independent of the CLD when the rubber specimens are loaded with a normal force of 100 N. However, at higher load, the optimal range of CLD decreases rapidly from 136 to 241 mu mol x cm(-3). Furthermore, a significant influence of SIC on CC resistance was confirmed in the range of CLD from 181 to 241 mu mol x cm(-3). Moreover, in the range of CLD from 181 to 241 mu mol x cm(-3) the predominant effect of NR on CC resistance was observed. Finally, an effect of degradation of cross-link network on CC properties due to rubber curing in the reversion has been discussed.Ministry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2022/006