University of Belgrade
  • Belgrade, Serbia
Recent publications
  • Mohamed Alboraie
    Mohamed Alboraie
  • Tawesak Tanwandee
    Tawesak Tanwandee
  • Xiaoyuan Xu
    Xiaoyuan Xu
  • [...]
  • Yasser Fouad
    Yasser Fouad
HERISTEM is a strategic partnership project funded by the Erasmus+ Programme with the main goal of gathering together institutions of higher education, those dealing with heritage preservation and protection, and small businesses to provide transfer of knowledge, skills, and good practices of STEM in the field of archaeology, through intensive courses, seminars, exhibitions, and students/teachers mobility. The outbreak of the COVID-19 pandemic and consequent travel restrictions caused inevitable adjustments of project activities. New forms of online content were explored, engaging both professional (online conference, Archaeological Dialogues Without Isolation), and wider audiences (video and interactive content for Researchers’ Night 2020). The feedback and evaluation of these activities revealed that they were great outreach initiatives with high interest from the audience and high engagement with online content, and therefore new possibilities for communication with the public.
  • Edoardo De Tommasi
    Edoardo De Tommasi
  • Ilaria Rea
    Ilaria Rea
  • Maria Antonietta Ferrara
    Maria Antonietta Ferrara
  • [...]
  • Angela Wulff
    Angela Wulff
Nature provides various organisms with ordered or quasi-ordered dielectric nanostructures that enable several animals, plants, and protists to manipulate light, optimizing inter- and intra-species communication, camouflage, or solar light harvesting. In particular, diatom microalgae possess nanostructured silica cell walls, known as frustules, which efficiently interact with optical radiation through multiple diffractive, refractive, scattering, waveguiding, and frequency down-conversion mechanisms. These properties contribute to diatoms’ efficiency in photosynthesis, UV tolerance, and possibly influence the phototaxis mechanisms of motile species. In our study, we utilized several imaging, spectroscopic, and numerical techniques to explore the optical functionalities of individual frustule components in the pennate, motile diatom Pleurosigma strigosum. We discuss the implications of frustule photonic properties on the living cell, and envision the exploitation of these properties in multifunctional, bio-derived photonic devices.
  • Irena Ilic
    Irena Ilic
  • Goran Babic
    Goran Babic
  • Aleksandra Dimitrijevic
    Aleksandra Dimitrijevic
  • [...]
  • Milena Ilic
    Milena Ilic
Introduction Women who receive a result of an abnormal Papanicolaou (Pap) smear can fail to participate in follow up procedures, and this is often due to anxiety. This study aimed to apply artificial neural networks (ANN) in prediction of anxiety in women with an abnormal Pap smear test, prior to and following diagnostic procedures. Methods One hundred-seventy two women who received an abnormal Pap screening result took part in this study, completing a questionnaire about socio-demographic characteristics and Hospital Anxiety and Depression Scale (HADS), right before and two to four weeks after diagnostics (i.e. colposcopy/biopsy/endocervical curettage). A feedforward back-propagation multilayer perceptron model was applied in analysis. Results Prior to diagnostic procedures 50.0% of women experienced anxiety, while after diagnostics anxiety was present in 61.6% of women. The correlation-based feature selection showed that anxiety prior to diagnostic procedures was associated with the use of sedatives, worry score, depression score, and score for concern about health consequences. For anxiety following diagnostics, predictors included rural place of residence, depression score, history of spontaneous abortion, and score for tension and discomfort during colposcopy. The ANN models yielded highly accurate anxiety prediction both prior and after diagnostics, 76.47% and 85.30%, respectively. Conclusion The presented findings can aid in identification of those women with a positive Pap screening test who could develop anxiety and thus represent the target group for psychological support, which would consequently improve adherence to follow-up diagnostics and enable timely treatment, finally reducing complications and fatal outcome.
  • Krisztina Rácz
    Krisztina Rácz
The past decade has seen mass emigration of Hungarians from Serbia to the kin-state and Western European countries. This has resulted in new ways of understanding what it means to belong to the community, both empirically and in terms of theorizing it, and both for those in Serbia and those abroad. This article claims that there are virtual platforms where members of this ethnic community (re)create their identities, and that this happens through relating to certain common themes. For this reason, I analyze the common themes of two humorous Facebook pages – namely, rurality, food, language use, ethnic others, and crossing borders – popular among Vojvodina Hungarians. The article argues that these elements of identity connect members of the community who live in Vojvodina and those who have emigrated to the kin-state or diaspora. Therefore, in order to unpack the complex dynamics of identification of a national minority community with high diasporic tendencies, an approach that connects the above topics to the concepts of community, nostalgia, home, minority, and borders, and in more general terms the lens of national minority and diaspora studies is needed.
International Linear Collider (ILC) is a viable option for realization of a future Higgs factory. With proven accelerator technology and technically mature detector design, ILC offers well-understood physics program in the top, EW and Higgs sectors. Clean environment of electron–positron collisions, together with beam polarization of both beams and center-of-mass reach at a TeV scale, will make ILC a precision tool to probe realizations of new physics. The above will be illustrated on examples of fully simulated measurements in the Higgs sector, including Higgs couplings, Higgs self-coupling, CP violation measurements and Higgs exotic decay studies at ILC.
Machine learning (ML) models have gained significant attention in a variety of applications, from computer vision to natural language processing, and are almost always based on big data. There are a growing number of applications and products with built-in machine learning models, and this is the area where software engineering, artificial intelligence and data science meet. The requirement for a system to operate in a real-world environment poses many challenges, such as how to design for wrong predictions the model may make; How to assure safety and security despite possible mistakes; which qualities matter beyond a model’s prediction accuracy; How can we identify and measure important quality requirements, including learning and inference latency, scalability, explainability, fairness, privacy, robustness, and safety. It has become crucial to test thoroughly these models to assess their capabilities and potential errors. Existing software testing methods have been adapted and refined to discover faults in machine learning and deep learning models. This paper covers a taxonomy, a methodologically uniform presentation of all presented solutions to the aforementioned issues, as well as conclusions about possible future development trends. The main contributions of this paper are a classification that closely follows the structure of the ML-pipeline, a precisely defined role of each team member within that pipeline, an overview of trends and challenges in the combination of ML and big data analytics, with uses in the domains of industry and education.
Purpose To evaluate the changes in abutment screw removal torque value (RTV) of anatomic, original hybrid, and non‐original hybrid abutments after simulated clinical use. Materials and Methods Ninety‐three implant‐abutment‐crown specimens were divided into groups according to abutment types ( n = 31): anatomic (stock) (A), original hybrid (OH), and non‐original hybrid (NOH). After the initial abutment screw tightening, the specimens were subjected to five screw tightening (insertion/removal) cycles, or to 5000 thermal cycles with 500,000 chewing cycles combined with one or five screw tightening cycles. RTV measurements and surface analysis using scanning electron microscope were performed before and after aging. The impact of abutment types and aging treatments on RTV was determined using two‐way repeated measures ANOVA, data were described with mean ± SD and range, whereas the differences were significant at p < 0.05. Results A significant interaction was found between abutment types and screw tightening cycles only ( p = 0.036) or combined with thermomechanical aging ( p < 0.001) on RTV. RTV was lower in NOH than in A and OH groups after screw tightening and thermomechanical aging ( p < 0.05). Before aging, the NOH abutment screw was slightly more damaged than OH and A abutment screws. After aging, screw damage was more pronounced on the surfaces of hybrid abutments, and more evident in the NOH group. Conclusions The abutment screw RTV of anatomic, original hybrid, and non‐original hybrid abutments become significantly lower after abutments undergo screw tightening and/or thermomechanical aging cycles, with higher RTV loss in hybrid abutments, especially non‐original ones.
The aim of this study is to determine the metric stability of the one-month handgrip test (HGT) in order to define the contractile characteristics of the biological variation of maximal isometric strength ( F max ) and maximal isometric rate of force development ( RFD max ) of the handgrip in two different testing regimes (classic and impulse). The study was conducted with a total of 16 participants (11 men and 5 women). Testing was performed using an isometric handgrip probe with a standardized test protocol and equipment sports medical solutions (SMS). The results of F max showed a low relative standard error of the mean ( RS = 1.33 %), a high value of inter-class correlation ( ICC = 0.996), and no statistically significant change in trend ( p > 0.05) during the testing period. Therefore, can conclude that the HGT procedure in classic mode can be used as a stable parameter in a human subject sample. However, the RFD max results showed a low RS (2.13 %) and a high ICC value (0.996), but a statistically significant change of trend ( p < 0.05) during the measurement period. The regression constant ( RCO ) trend was 42.629 N/s, which can be attributed to learning or to the adaptive effects of the test procedure, which triggered similar adaptation processes as the training. In general, it can be concluded that the handgrip can be used to sensitively measure the effects of different long-term health improvements, or the effects of different medical/health exercises, rehabilitation programs, effects of medication applications, or dietary supplements for F max . However, further research should be conducted for the RFD max considering the metric stability parameters.
The role of welding in fracture mechanics development is considered from historical point of view. Starting point was analysis of Schenectady ship failure during the II World War, leading to development of linear elastic, as well as elastic-plastic fracture mechanics, soon afterwards. Two case studies are described to illustrate weldment fracture mechanics and structural integrity assessment.
Herein, we report the photoluminescence properties of Bi³⁺-sensitized BaYF5:10 mol%Eu³⁺ nanoparticles. The emission spectra feature Eu³⁺ peaks corresponding to transitions from the ⁵D0 excited to ⁷FJ (J = 1, 2, 3, 4) lower levels with two dominant emissions positioned in the orange-red (∼ 592 nm, ⁵D0 → ⁷F1) and deep-red (∼ 697 nm, ⁵D0 → ⁷F4) regions. Upon 265 nm excitation, the emission intensity increases with an increase of Bi³⁺ concentration up to 20 mol%. Due to the energy transfer from Bi³⁺ to Eu³⁺ ions, the integrated intensity of Eu³⁺ emission in the Bi³⁺ co-doped BaYF5:10 mol%Eu³⁺ is 216% stronger than in the Bi³⁺-free sample. Our findings demonstrated that BaYF5:Eu,Bi has potential in plant lighting technology due to strong emission in red and deep-red spectral areas.
Investment refers to allocating funds in the expectation of some benefit in the future which in financial terms is the return. In the presence of various investment alternatives, the decision maker stands confused as to which option would offer him the highest return. Thus, the problem of appropriate investment selection can be treated as a multi-objective decision-making (MODM) problem that involves optimization of return on investment, time, risk, etc. However, the time, return, and risk involved in such problems cannot be defined in precise units and are fuzzy in nature. Amidst such a scenario in addition to fuzzy set (FS) theory, intuitionistic fuzzy sets (IFSs) which provide a mathematical framework to deal with imprecise information of the real world can be of much help. It can be seen as an alternative to describe a FS-in situation when the existing data is not enough to define a usual FS. Against this backdrop, this paper is an attempt to develop an IF multi-objective linear model (MOLM) for the investment selection problem where the coefficients of the objective functions (OFs) are represented by IF linear membership (MM) and non-membership (N-MM) functions. The constraints in the problem are treated as crisp. The application of the methodology is explained with the help of a numerical example. Comparing the fuzzy and intuitionistic models it is seen that the IFO model gives optimal results in selection and order allocations to the investors. Also, a Pareto optimality test is performed to test the strength of the solution.
The protein structure, gel changes, and chewing properties of low‐sodium myofibrillar protein (MP) prepared by compound chloride salts (KCl/MgCl2, KCl/CaCl2, and KCl/MgCl2/CaCl2) and different substitution degrees (10%, 25%, and 40%) at same ionic strength (0.6 M) were investigated. The results revealed that the low‐sodium MP gels containing CaCl2 manifested more liquid loss and less moisture content accompanied by obvious morphological shrinkage, while KCl/MgCl2 contributed to the gel juiciness. At high substitution degree of 40%, KCl/CaCl2 substitution rendered the gel with dense structure and highest strength, but worse water retention capacity. Using other compound chloride salts influenced the chewing efficiency, and CaCl2 substitution made the gel relatively hard to chew. The inhomogeneous structure accompanied by cluster blocks in KCl/CaCl2‐substituted MP gel accelerated the overall fracture rate. During heating process, more proteins in CaCl2‐substituted MP did not participate in gel formation, intervening the final gel properties. The chloride salt mixtures containing MgCl2, rather than CaCl2, avoided or alleviated the liquid loss and shrinkage of low‐sodium MP gel within the substitution degree of 10%–40%, and substitution degree not exceeding 25% was more reasonable for the controlled qualities.
Purpose The STAT trial is a multicenter randomized controlled trial in 12 centers worldwide aiming to determine the most effective operation for neonates with necrotizing enterocolitis (NEC) requiring intestinal resection: stoma formation (ST) or primary anastomosis (PA). Methods Infants having a primary laparotomy for NEC were randomized intraoperatively to PA or ST if the operating surgeon thought that both were viable treatment options for that patient. The primary outcome (duration of parenteral nutrition [PN]) was evaluated by Cox regression. Results Eighty patients were recruited from 2010 to 2019. Infants undergoing anastomosis finished PN significantly earlier than patients undergoing stoma (hazard ratio PA vs. ST 2.38, 95% CI 1.36–4.12 p = 0.004). There was no difference in mortality between the two groups (PA 4/35 vs. ST 8/38 p = 0.35) or in the rate of complications requiring further unplanned operations (p = n.s.). Multiple intestinal complications were more frequent in the stoma group compared to the anastomosis group (ST 12/26 vs. PA 5/31, p = 0.02, Fisher’s Exact test). Conclusion At laparotomy for NEC, when there is no disease distal to resected intestine, primary anastomosis should be performed as it enhances the recovery from NEC, reduces the risk of multiple intestinal complications and does not increase adverse outcomes.
Background Although repeatedly confirmed, the molecular nature of gene-environment (GxE) interactions has rarely been investigated in the clinical context of mood disorders. This study assesses the relationship between HTR2A genetic variants and the modulatory effect of inflammation in a collective cohort of patients with major depressive disorder (MDD) and bipolar disorder (BD), as a unified group with two distinct phenotypes. Methods The study included 138 patients with acute mood episodes (BD = 83; MDD = 55). HTR2A rs6313 and rs6314 genotyping was performed while measuring platelet-derived indicators of inflammation (platelet count (PLT), mean platelet volume (MPV), plateletcrit, and platelet distribution width) and the MPV/PLT ratio. Results The HTR2A rs6313 variant is a significant predictor of the polarity phenotype in mood disorders, with the MPV/PLT ratio moderating this relationship, but only under low-inflammatory conditions. In more pronounced inflammatory states, genetic influences lose their predictive role. Conclusions To our knowledge, this is the first study to investigate the complex interplay between platelet-derived indicators of inflammation and HTR2A variants in the context of mood disorders. Without pro-inflammatory conditions, mood disorders seem to be more genetically determined. Under pro-inflammatory conditions, phenotypic presentation is less dependent on genetic factors. GxE interactions in mood disorders are multifaceted, context-dependent and relevant for assessing their clinical presentation and course.
Background Acute intracranial occlusion of the internal carotid artery (ICA) can be distinguished into (a) occlusion of the terminal ICA, involving the proximal segments of the middle or anterior cerebral artery (ICA-L/-T) and (b) non-terminal intracranial occlusions of the ICA with patent circle of Willis (ICA-I). While patients with ICA-L/-T occlusion were included in all randomized controlled trials on endovascular therapy (EVT) in anterior large vessel occlusion, data on EVT in ICA-I occlusion is scarce. We thus aimed to evaluate effectiveness and safety of EVT in ICA-I occlusions in comparison to ICA-L/-T occlusions. Methods A large international multicentre cohort was searched for patients with intracranial ICA occlusion treated with EVT between 2014 and 2023. Patients were stratified by ICA occlusion pattern, differentiating ICA-I and ICA-L/-T occlusions. Baseline factors, technical (modified thrombolysis in cerebral infarction (mTICI) scale) and functional outcomes (modified Rankin scale [mRS] at 3 months) as well as rates of (symptomatic) intracranial hemorrhage ([s]ICH) were analyzed. Results Of 13,453 patients, 1825 (13.6%) had isolated ICA occlusion. ICA-occlusion pattern was ICA-I in 559 (4.2%) and ICA-L/-T in 1266 (9.4%) patients. Age (years: 74 vs 73), sex (female: 45.8% vs 49.0%) and pre-stroke functional independency (pre-mRS ⩽ 2: 89.9% vs 92.2%) did not differ between the groups. Stroke severity was lower in ICA-I patients (NIHSS at admission: 14 [7–19] vs 17 [13–21] points). EVT was similarly successful with respect to technical (mTICI2b/3: 76.1% (ICA-I) vs 76.6% (ICA-L/-T); aOR 1.01 [0.76–1.35]) and functional outcome (mRS ordinal shift cOR 1.01 [0.83–1.23] in adjusted analyses. Rates of ICH (18.9% vs 34.5%; aOR 0.47 [0.36–0.62] and sICH (4.7% vs 7.3%; aOR 0.58 [0.35–0.97] were lower in ICA-I patients. Conclusion EVT might be performed safely and similarly successful in patients with ICA-I occlusions as in patients with ICA-L/-T occlusions.
This study examines the formidable and complex challenge of insider threats to organizational security, addressing risks such as ransomware incidents, data breaches, and extortion attempts. The research involves six experiments utilizing email, HTTP, and file content data. To combat insider threats, emerging Natural Language Processing techniques are employed in conjunction with powerful Machine Learning classifiers, specifically XGBoost and AdaBoost. The focus is on recognizing the sentiment and context of malicious actions, which are considered less prone to change compared to commonly tracked metrics like location and time of access. To enhance detection, a term frequency-inverse document frequency-based approach is introduced, providing a more robust, adaptable, and maintainable method. Moreover, the study acknowledges the significant impact of hyperparameter selection on classifier performance and employs various contemporary optimizers, including a modified version of the red fox optimization algorithm. The proposed approach undergoes testing in three simulated scenarios using a public dataset, showcasing commendable outcomes.
Objective Cortical atrophy close to medial temporal structures has been described consistently in patients with temporal lobe epilepsy (TLE). Successful TLE surgery may have a neuroprotective effect preventing further atrophy of temporal and extratemporal cortex. However, the effects of epilepsy surgery on subcortical structures demand additional enlightenment. This work aimed to determine how epilepsy surgery affects volumes of subcortical structures in medically refractory temporal lobe epilepsy patients. Methods We compared MRI volumes of subcortical structures in 62 patients with TLE (36 left, 26 right) before and after anterior temporal lobectomy with 38 TLE patients (20 left, 18 right) who were considered to be good surgical candidates and had at least two brain MRIs. Results There were no volume differences in subcortical structures on preoperative and initial MRIs of non‐operated TLE patients. At baseline, the ipsilateral thalamus and putamen in TLE patients were marginally smaller than contralateral structures. Operated patients showed a significant postoperative volume reduction in ipsilateral thalamus, putamen, and globus pallidus. In contrast, there were no significant volumetric reductions in non‐operated patients longitudinally. There were no volumetric changes associated with different surgical outcomes or different postoperative cognitive outcomes. Significance Our study demonstrated postoperative volume loss of thalamus, putamen and globus pallidus ipsilaterally to the side of resection. Our findings suggest surgery‐related changes, likely Wallerian degeneration within subcortical networks not related to seizure or cognitive outcome. Plain Language Summary We studied 100 patients with epilepsy, comparing those who had surgery to those who did not. After surgery, the thalamus, putamen and globus pallidus on the same side as the surgery shrank significantly, but not in non‐surgery patients. This suggests surgery‐related changes in deeper brain structures, unrelated to seizure freedom or cognitive outcomes. This research sheds additional light on the response of the subcortical structure to epilepsy surgery, highlighting potential areas for further study.
Over the past three decades, there has been increasing interest in miniaturized percutaneous nephrolithotomy (mPCNL) techniques featuring smaller tracts as they offer potential solutions to mitigate complications associated with standard PCNL (sPCNL). However, despite this growing acceptance and recognition of its benefits, unresolved controversies and acknowledged limitations continue to impede widespread adoption due to a lack of consensus on optimal perioperative management strategies and procedural tips and tricks. In response to these challenges, an international panel comprising experts from the International Alliance of Urolithiasis (IAU) took on the task of compiling an expert consensus document on mPCNL procedures aimed at providing urologists with a comprehensive clinical framework for practice. This endeavor involved conducting a systematic literature review to identify research gaps (RGs), which formed the foundation for developing a structured questionnaire survey. Subsequently, a two-round modified Delphi survey was implemented, culminating in a group meeting to generate final evidence-based comments. All 64 experts completed the second-round survey, resulting in a response rate of 100.0%. Fifty-eight key questions were raised focusing on mPCNLs within 4 main domains, including general information (13 questions), preoperative work-up (13 questions), procedural tips and tricks (19 questions), and postoperative evaluation and follow-up (13 questions). Additionally, 9 questions evaluated the experts’ experience with PCNLs. Consensus was reached on 30 questions after the second-round survey, while professional statements for the remaining 28 key questions were provided after discussion in an online panel meeting. mPCNL, characterized by a tract smaller than 18 Fr and an innovative lithotripsy technique, has firmly established itself as a viable and effective approach for managing upper urinary tract stones in both adults and pediatrics. It offers several advantages over sPCNL including reduced bleeding, fewer requirements for nephrostomy tubes, decreased pain, and shorter hospital stays. The series of detailed techniques presented here serve as a comprehensive guide for urologists, aiming to improve their procedural understanding and optimize patient outcomes.
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10,159 members
Tanja Vukov
  • Department of evolutionary biology (IBISS)
Ljubiša Stanisavljević
  • Department of Invertebrate Zoology and Entomology
Ivica Bradaric
  • Vinca Institute of Nuclear Science
Veljko Djokic
  • Department of Chemical Engineering
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Belgrade, Serbia
Head of institution
Владимир Бумбаширевић