Clinical Efficacy of Extracellular Vesicle Therapy in Periodontitis: Reduced Inflammation and Enhanced Regeneration.

Periodontitis, a prevalent inflammatory condition, affects the supporting structures of teeth, leading to significant oral health challenges. Traditional treatments have primarily focused on mechanical debridement, antimicrobial therapy, and surgery, which often fail to restore lost periodontal structures. Emerging as a novel approach in regenerative medicine, extracellular vesicle (EV) therapy, including exosomes, leverages nano-sized vesicles known for facilitating intercellular communication and modulating physiological and pathological processes. This study is a proof-of-concept type that evaluates the clinical efficacy of EV therapy as a non-surgical treatment for stage I-III periodontitis, focusing on its anti-inflammatory and regenerative potential. The research involved seven patients undergoing the therapy, and seven healthy individuals. Clinical parameters, including the plaque index, bleeding on probing, probing depth, and attachment level, were assessed alongside cytokine levels in the gingival crevicular fluid. The study found significant improvements in clinical parameters, and a marked reduction in pro-inflammatory cytokines post-treatment, matching the levels of healthy subjects, underscoring the therapy's ability to not only attenuate inflammation and enhance tissue regeneration, but also highlighting its potential in restoring periodontal health. This investigation illuminates the promising role of EV therapy in periodontal treatment, advocating for a shift towards therapies that halt disease progression and promote structural and functional restoration of periodontal tissues.

Robotic mirror therapy for stroke rehabilitation through virtual activities of daily living.

Mirror therapy is a standard technique of rehabilitation for recovering motor and vision abilities of stroke patients, especially in the case of asymmetric limb function. To enhance traditional mirror therapy, robotic mirror therapy (RMT) has been proposed over the past decade, allowing for assisted bimanual coordination of paretic (affected) and contralateral (healthy) limbs. However, state-of-the-art RMT platforms predominantly target mirrored motions of trajectories, largely limited to 2-D motions. In this paper, an RMT platform is proposed, which can facilitate the patient to practice virtual activities of daily living (ADL) and thus enhance their independence. Two similar (but mirrored) 3D virtual environments are created in which the patients operate robots with both their limbs to complete ADL (such as writing and eating) with the assistance of the therapist. The recovery level of the patient is continuously assessed by monitoring their ability to track assigned trajectories. The patient's robots are programmed to assist the patient in following these trajectories based on this recovery level. In this paper, the framework to dynamically monitor recovery level and accordingly provide assistance is developed along with the nonlinear controller design to ensure position tracking, force control, and stability. Proof-of-concept studies are conducted with both 3D trajectory tracking and ADL. The results demonstrate the potential use of the proposed system to enhance the recovery of the patients.

Harnessing the Stem Cell Niche in Regenerative Medicine: Innovative Avenue to Combat Neurodegenerative Diseases.

Regenerative medicine harnesses the body's innate capacity for self-repair to restore malfunctioning tissues and organs. Stem cell therapies represent a key regenerative strategy, but to effectively harness their potential necessitates a nuanced understanding of the stem cell niche. This specialized microenvironment regulates critical stem cell behaviors including quiescence, activation, differentiation, and homing. Emerging research reveals that dysfunction within endogenous neural stem cell niches contributes to neurodegenerative pathologies and impedes regeneration. Strategies such as modifying signaling pathways, or epigenetic interventions to restore niche homeostasis and signaling, hold promise for revitalizing neurogenesis and neural repair in diseases like Alzheimer's and Parkinson's. Comparative studies of highly regenerative species provide evolutionary clues into niche-mediated renewal mechanisms. Leveraging endogenous bioelectric cues and crosstalk between gut, brain, and vascular niches further illuminates promising therapeutic opportunities. Emerging techniques like single-cell transcriptomics, organoids, microfluidics, artificial intelligence, in silico modeling, and transdifferentiation will continue to unravel niche complexity. By providing a comprehensive synthesis integrating diverse views on niche components, developmental transitions, and dynamics, this review unveils new layers of complexity integral to niche behavior and function, which unveil novel prospects to modulate niche function and provide revolutionary treatments for neurodegenerative diseases.

Cytokine Dynamics in Autism: Analysis of BMAC Therapy Outcomes.

Autism spectrum disorder (ASD) has recently been linked to neuroinflammation and an aberrant immune response within the central nervous system. The intricate relationship between immune response and ASD remains elusive, with a gap in understanding the connection between specific immune mechanisms and neural manifestations in autism. In this study, we employed a comprehensive statistical approach, fusing both overarching and granular methods to examine the concentration of 16 cytokines in the cerebrospinal fluid (CSF) across each autologous bone marrow aspirate concentrate (BMAC) intrathecal administration in 63 male and 17 female autism patients. Following a six-month period post the third administration, patients were stratified into three categories based on clinical improvement: Group 1- no/mild (28 subjects), Group 2-moderate (16 subjects), and Group 3-major improvement (15 subjects). Our integrated analysis revealed pronounced disparities in CSF cytokine patterns and clinical outcomes in autism subjects pre- and post-BMAC transplantation. Crucially, our results suggest that these cytokine profiles hold promise as predictive markers, pinpointing ASD individuals who might not exhibit notable clinical amelioration post-BMAC therapy.

Potential Impact of Polymorphisms in Toll-like Receptors 2, 3, 4, 7, 9, miR-146a, miR-155, and miR-196a Genes on Osteoarthritis Susceptibility.

Osteoarthritis (OA) is a progressive inflammatory disease of synovial joints and a leading cause of disability among adults. Inflammation-related genes, including genes for Toll-like receptors (TLRs), are tightly controlled by several microRNAs that, in addition to their pivotal role in the epigenetic regulation of target genes, are ligands for TLR activation and downstream signaling. Thus, we evaluated the association between OA risk and genetic variants in TLR2, TLR3, TLR4, TLR7, TLR9, and microRNAs that regulate TLRs signaling miR146a, miR155, and miR196a2. Our study group consisted of 95 surgically treated OA patients and a control group of 104 healthy individuals. Genetic polymorphisms were determined using TaqMan real-time PCR assays (Applied Biosystems). Adjusted logistic regression analysis demonstrated that polymorphisms in TLR4 rs4986790 (OR = 2.964, p = 0.006), TLR4 rs4986791 (OR = 8.766, p = 0.00001), and TLR7 rs385389 (OR = 1.579, p = 0.012) increased OA risk, while miR-196a2 rs11614913 (OR = 0.619, p = 0.034) was significantly associated with decreased OA risk. Our findings indicate that polymorphisms in the TLR4 and TLR7 genes might increase OA risk and suggest a novel association of miR-196a2 polymorphism with decreased OA susceptibility. The modulation of TLRs and miRNAs and their cross-talk might be an attractive target for a personalized approach to OA management.

Treatment of vascular non-iatrogenic injuries of upper and lower extremities in tertiary vascular center.

BACKGROUND: The purpose of this study was to examine demographic and baseline characteristics of patients with vascular injuries of extremities and to define the most relevant factors which influenced an early outcome, as well as limb salvage after the management of vascular trauma. METHODS: This study used the database that included 395 patients with peripheral arterial injuries, who were treated in the tertiary vascular university center in the period between 2005-2020. Exclusion criteria were isolated thoracic, abdominal and neck injuries as well as iatrogenic injuries and injuries of intravenous addicts. Univariate binary logistic regression analysis and multiple logistic regression were used to determine risk factors for lomb loss (after vascular reconstruction) or mortality. Decision to perform primary amputation (without vascular reconstruction) was based on surgeons' preference and experience. RESULTS: Out of 395 vascular injuries treated in the period 2005-2020, 210 (53.2%) presented with non-iatrogenic vascular injuries of upper and lower extremities were analyzed. According to the univariate regression analysis, hemorrhage as the main clinical manifestation on admission (P=0.035) and early reintervention (P=0.048) increased, while an early patency of repaired artery (0.010) significantly decreased a 30-day amputation rate. Multivariate logistic regression analysis of these three variables showed that only early patency of repaired artery significantly decreased the early amputation rate (P=0.009). CONCLUSIONS: Based on presented experience, the patency of vascular reconstruction plays a crucial role in limb salvage in patients with non-iatrogenic peripheral vascular injuries. All factors that might influence the patency should be in focus of improvement.

A Formal Characterization of Activation Functions in Deep Neural Networks.

In this article, a mathematical formulation for describing and designing activation functions in deep neural networks is provided. The methodology is based on a precise characterization of the desired activation functions that satisfy particular criteria, including circumventing vanishing or exploding gradients during training. The problem of finding desired activation functions is formulated as an infinite-dimensional optimization problem, which is later relaxed to solving a partial differential equation. Furthermore, bounds that guarantee the optimality of the designed activation function are provided. Relevant examples with some state-of-the-art activation functions are provided to illustrate the methodology.

Stem Cell Homing in Intrathecal Applications and Inspirations for Improvement Paths.

A transplanted stem cell homing is a directed migration from the application site to the targeted tissue. Intrathecal application of stem cells is their direct delivery to cerebrospinal fluid, which defines the homing path from the point of injection to the brain. In the case of neurodegenerative diseases, this application method has the advantage of no blood-brain barrier restriction. However, the homing efficiency still needs improvement and homing mechanisms elucidation. Analysis of current research results on homing mechanisms in the light of intrathecal administration revealed a discrepancy between in vivo and in vitro results and a gap between preclinical and clinical research. Combining the existing research with novel insights from cutting-edge biochips, nano, and other technologies and computational models may bridge this gap faster.

A painful symphony: the presence of overuse syndrome in professional classical musicians / Una sinfonía dolorosa: la presencia del síndrome de uso excesivo en músicos clásicos profesionales

Musculoskeletal problems are common in instrumental musicians. Little is known about the factors that place musicians at risk, and the ways in which musicians can prevent these problems. Overuse syndrome is the most reported diagnosis among instrumental musicians suffering from playing related musculoskeletal injuries. The study group comprised 50 musicians employed in Symphony Orchestra of the Serbian National Theatre of Novi Sad. Out of the 50 musicians, 30 (60 %) are male and 20 (40 %) female. Higher frequencies of the presence of musculoskeletal symptoms were neck, region of trapezius, back, shoulder, wrist, hand and arm. A larger number of musicians (81.8 %) had perception of high demand of the profession. This investigation with professional classical musicians should show the music-medical interest.

Los problemas musculo-esqueléticos son comunes en los músicos instrumentales. Poco se sabe sobre los factores que ponen en riesgo a los músicos y las formas en que los ellos pueden prevenir estos problemas. El síndrome de uso excesivo es el diagnóstico más informado entre los músicos instrumentales que sufren lesiones musculo-esqueléticas relacionadas al uso de instrumentos musicales. El grupo de estudio estuvo compuesto por 50 músicos de la Orquesta Sinfónica del Teatro Nacional Serbio de Novi Sad. De los 50 músicos, 30 (60 %) eran hombres y 20 (40 %) mujeres. La frecuencia más alta de presencia de síntomas musculoesqueléticos se produjo en el cuello, músculo trapecio, espalda, hombro, muñeca, mano y brazo. Un mayor número de músicos (81,8 %) tuvo una percepción de alta demanda de la profesión. Esta investigación con músicos clásicos profesionales debería ser de interés médico-musical.

Synthesis and preliminary screening for the biological activity of some steroidal Δ4-unsaturated semicarbazone derivatives.

Eleven new steroidal mono- and bis(semicarbazones) 2a-e, 4d and 3a-e have been prepared starting from various 3-oxo-α,ß-unsaturated steroids. Mono-semicarbazones 2a-e were further subjected to ethyl chloroacetate in boiling absolute ethanol but, instead of expected intramolecular cyclocondensation reaction products, the new carbazate esters 5a-e were obtained. The structures of all synthesized compounds and identification of each E/Z isomer were deduced by elemental analysis, HRMS, NMR, and IR spectroscopy. Preliminary screening for the cytotoxic activity in vitro of the new compounds has been conducted against three cancer cell lines, K562, Jurkat and HeLa cells. HeLa cells were the most sensitive while K562 cells were the least sensitive to the cytotoxic action of the novel steroid derivatives. Compounds 2e, 3c and 5e were found to have the best but still moderate cytotoxic effects. All tested compounds showed very weak antimicrobial activities. These results demonstrate that the replacement of thioxo group with carbonyl group in steroidal hydrazone derivatives resulted in decrease in their biological activity.

Prevalence of third coronary artery: variation or constant coronary artery? / Prevalencia de la tercera arteria coronaria: ¿variación o arteria coronaria constante?

Third coronary artery or supernumerary coronary artery is a direct branch from right aortic sinus and it supplies pulmonary conus and upper part of right ventricle. Third coronary artery is an important bridge for collateral circulation between right and left coronary system. The aim of this study was to determine the number of arteries that origin from right aortic sinus, their frequency and position. The study included 55 adult human hearts collected from Department of Anatomy. The hearts were morphologically studied by gross dissection for the prevalence and topographical anatomy of supernumerary coronary arteries. Out of 55 hearts, 26 (47.3 %) had one right coronary artery, 23 (41.8 %) had two right coronary arteries, and 6 (10.9 %) had three coronary arteries. The supernumerary arteries arises from the right aortic sinus. Right supernumerary coronary arteries may be present in about 52.7 % of the Serbian population. Interpretation of signs and symptoms of coronary occlusion should therefore consider possible contribution of this blood vessels.

La tercera arteria coronaria o arteria coronaria supernumeraria es una rama directa del seno aórtico derecho y su ministra el cono pulmonar y la parte superior del ventrículo derecho. La tercera arteria coronaria es importante para la circulación colateral entre el sistema coronario derecho e izquierdo. El objetivo de este estudio fue determinar el número de arterias de origen del seno aórtico derecho, su frecuencia y posición. El estudio incluyó 55 corazones humanos adultos pertenecientes al Departamento de Anatomía. Los corazones se estudiaron morfológicamente mediante disección macroscópica para determinar la prevalencia y la anatomía topográfica de las arterias coronarias supernumerarias. De 55 corazones, 26 (47,3 %) tenían una arteria coronaria derecha, 23 (41,8 %) tenían dos arterias coronarias derechas, y 6 (10,9 %) tenían tres arterias coronarias. Las arterias supernumerarias surgen del seno aórtico derecho. Las arterias coronarias supernumerarias derechas pueden estar presentes en aproximadamente el 52,7 % de la población serbia. La interpretación de los signos y síntomas de la oclusión coronaria debería considerar la posible contribución de estos vasos sanguíneos.

In vitro and in vivo antimelanoma effect of ethyl ester cyclohexyl analog of ethylenediamine dipropanoic acid.

Melanoma, an aggressive skin tumor with high metastatic potential, is associated with high mortality and increasing morbidity. Multiple available chemotherapeutic and immunotherapeutic modalities failed to improve survival in advanced disease, and the search for new agents is ongoing. The aim of this study was to investigate antimelanoma effects of O,O-diethyl-(S,S)-ethylenediamine-N,N'di-2-(3-cyclohexyl) propanoate dihydrochloride (EE), a previously synthesized and characterized organic compound. Mouse melanoma B16 cell viability was assessed using acid phosphatase, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, sulforhodamine B, and lactate dehydrogenase assays. Apoptosis and autophagy were investigated using flow cytometry, fluorescence and electron microscopy, and western blotting. In vivo antitumor potential was assessed in subcutaneous mouse melanoma model after 14 days of treatment with EE. Tumor mass and volume were measured, and RT-PCR was used for investigating the expression of autophagy-related, proapoptotic, and antiapoptotic molecules in tumor tissue. Investigated organic compound exerts significant cytotoxic effect against B16 cells. EE induced apoptosis, as confirmed by phosphatidyl serine externalisation, caspase activation, and ultrastructural features typical for apoptosis seen on fluorescence and electron microscopes. The apoptotic mechanism included prompt disruption of mitochondrial membrane potential and oxidative stress. No autophagy was observed. Antimelanoma action and apoptosis induction were confirmed in vivo, as EE decreased mass and volume of tumors, and increased expression of several proapoptotic genes. EE possesses significant antimelanoma action and causes caspase-dependent apoptosis mediated by mitochondrial damage and reactive oxygen species production. Decrease in tumor growth and increase in expression of proapoptotic genes in tumor tissue suggest that EE warrants further investigation as a candidate agent in treating melanoma.

Anticancer potential of new steroidal thiazolidin-4-one derivatives. Mechanisms of cytotoxic action and effects on angiogenesis in vitro.

The synthesis and cytotoxic activities determination of new steroidal mono- and bis(thiazolidin-4-ones) 4a-f and 5a-f have been performed. Their anticancer action was also evaluated in comparison to previously synthesized and reported corresponding steroidal thiosemicarbazones. All compounds were obtained as stereoisomeric mixtures with different configuration (E or Z) in the hydrazone moiety at the C-3 position. After several consecutive crystallizations diastereomerically pure major (E)-isomers of mono-thiazolidin-4-ones were isolated. The structure and stereochemistry of 2,4-thiazolidinedione,2-[(17-oxoandrost-4-en-3-ylidene)hydrazone] were confirmed by X-ray analysis. A pathway for the formation of thiazolidin-4-one ring was proposed. The steroid thiazolidinone derivatives examined in this study exerted selective concentration-dependent cytotoxic activities on six tested malignant cell lines. Ten out of twelve examined compounds exhibited strong cytotoxic effects on K562 cells (IC50 values from 8.5µM to 14.9µM), eight on HeLa cells (IC50 values ranging from 8.9µM to 15.1µM) while against MDA-MB-361 cells six compouds exerted similar or even higher cytotoxic action (IC50 values from 12.7µM to 25.6µM) than cisplatin (21.5µM) which served as a positive control. Eight of these ten compounds showed high selectivity in the cytotoxic action against HeLa and K562 cancer cell lines when compared with normal human fibroblasts MRC-5 and normal human PBMC. The study of mechanisms of the anticancer activity of the two selected compounds, mono- and bis(thiazolidin-4-one) derivatives of 19-norandrost-4-ene-3,17-dione 4a and 5a, revealed that both of these compounds induced apoptosis in HeLa cells through extrinsic and intrinsic signalling pathways. Treatment of EA.hy926 cells with sub-toxic concentrations of these compounds led to the inhibition of cell connecting and sprouting, and tube formation. The synthesized compounds exhibited poor antioxidant activity.

Leptin and adiponectin levels in discordant dichorionic twins at 72 hours of age-associations with anthropometric parameters and insulin resistance.

BACKGROUND: Insulin resistance (IR) in adults has been associated with intrauterine growth restriction (IUGR). Leptin and adiponectin correlations with anthropometric parameters and IR at 72 h in discordant twins were tested. METHODS: We included 24 discordant (birth weight discordance ≥20% in relation to the heavier cotwin) and 30 concordant (birth weight discordance ≤10%) twins. RESULTS: A correlation between leptin (but not adiponectin) level and birth weight (BW), birth length and head circumference in IUGR twins was recorded (p<0.05). Insulin sensitivity (IS) and homeostatic model assessment (HOMA)-IR in IUGR twins were similar to appropriate-for-gestational-age cotwins and unrelated to adipokines. In IUGR twins, adiponectin and insulin associated positively. In larger concordant twins' leptin level correlated with HOMA-IR and insulin. CONCLUSIONS: Leptin, but not adiponectin, levels correlate positively with anthropometric parameters in IUGR twins. IR in IUGR twins is unrelated to adipokines in the first few days of life.

Viscoelastic properties of uncured resin composites: Dynamic oscillatory shear test and fractional derivative model.

OBJECTIVE: In this study we analyze viscoelastic properties of three flowable (Wave, Wave MV, Wave HV) and one universal hybrid resin (Ice) composites, prior to setting. We developed a mathematical model containing fractional derivatives in order to describe their properties. METHODS: Isothermal experimental study was conducted on a rheometer with parallel plates. In dynamic oscillatory shear test, storage and loss modulus, as well as the complex viscosity where determined. We assumed four different fractional viscoelastic models, each belonging to one particular class, derivable from distributed-order fractional constitutive equation. The restrictions following from the Second law of thermodynamics are imposed on each model. The optimal parameters corresponding to each model are obtained by minimizing the error function that takes into account storage and loss modulus, thus obtaining the best fit to the experimental data. RESULTS: In the frequency range considered, we obtained that for Wave HV and Wave MV there exist a critical frequency for which loss and storage modulus curves intersect, defining a boundary between two different types of behavior: one in which storage modulus is larger than loss modulus and the other in which the situation is opposite. Loss and storage modulus curves for Ice and Wave do not show this type of behavior, having either elastic, or viscous effects dominating in entire frequency range considered. SIGNIFICANCE: The developed models may be used to predict behavior of four tested composites in different flow conditions (different deformation speed), thus helping to estimate optimal handling characteristics for specific clinical applications.

An anatomical study of the lumbar external foraminal ligaments: appearance at MR imaging.

PURPOSE: The purpose of this study was to examine the MRI appearance of the ligaments within the external space of the lumbar intervertebral foramen by correlating MR images with the corresponding anatomic dissection of the cadaver lumbar spine. METHODS: This was a two part study. Part I of the anatomic study consisted of the dissection of lumbar specimens from one embalmed adult male cadaver. At each lumbar level the external ligamentous structures were identified and their origin, insertion and position were determined. Part II of the study consisted of the anatomical analysis of the external transforaminal ligaments in the 180 lumbar intervertebral foramina on the MR images (1.5 T) in the sagittal plane. The diagnostic procedure was performed on 18 individuals from 18 to 25 years of age. RESULTS: The external transforaminal ligaments were observed at all levels and from both sides in the lumbar intervertebral foramen. The presence of the superior corporotransverse ligament was found in 45.56% intervertebral foramina, while the inferior corporotransverse ligament was found in 61.67% intervertebral foramina in the MRI. CONCLUSION: Our results confirm that external transforaminal ligaments are common structures in the intervertebral foramen. The results of this study show that the external transforaminal ligaments can be clearly visualized in MR images. It is crucial to have previous knowledge of the cadaveric specimens to recognize the transforaminal ligaments in MR images. The presence of these ligaments is clinically important because the ligaments could be the cause of nerve root compression or the low back pain syndrome.

Steroid dimers-in vitro cytotoxic and antimicrobial activities.

The in vitro cytotoxic activity of previously synthesized steroid dimers with different spacer group (sulfide, trithiolane ring or phosphorotrithioate) and the substituent at C-17 position was tested for their possible effects against following human tumor cell lines: cervical adenocarcinoma (HeLa), chronic myelogenous leukemia (K562) and two human breast cancer cell lines (MDA-MB-361 and MDA-MB-453). These compounds, applied at micromolar concentrations, exhibited cytotoxic activity of different intensity (compared with cisplatin as a control), modality and selectivity in these malignant cell lines. The best activity against all four cell cancer lines was exhibited by dimer-sulfides. All screened compounds exerted concentration-dependent cytotoxic activity against leukemia K562 cells. The compounds which exerted the most pronounced cytotoxic action exhibited notably higher cytotoxic activities against K562, HeLa and MDA-MB-453 cells in comparison to resting and PHA-stimulated PBMC, pointing to a significant selectivity in their antitumor actions. Examination of the mechanisms of cytotoxicity on leukemia K562 cells revealed pro-apoptotic action of each of the investigated compounds applied at concentrations 2IC50. The most prominent pro-apoptotic action was exhibited by dimer-sulfide of cholest-4-en-3-one. Furthermore, almost all of the tested compounds at IC50 concentrations induced G1 phase cell cycle arrest in K562 cells. Antimicrobial activity against Gram-positive, Gram-negative bacteria and fungal cells, and toxicity to brine shrimp Artemia salina, were evaluated. There was no antibacterial activity. The best antifungal activity was exhibited against Saccharomyces cerevisiae by dimers linked with trithiolane ring, indicating a selective activity of investigated compounds.

A model of the viscoelastic behavior of flowable resin composites prior to setting.

OBJECTIVE: The aim of this study is to develop fractional derivative models for the assessment of viscoelastic properties related to handling characteristics of dental resin composites belonging to two classes: flowable (Revolution Formula 2 and Filtek Ultimate) and posterior "bulk-fill" flowable base (Smart Dentin Replace). METHODS: Rheological measurements on all materials tested in this study were performed using dynamic oscillatory rheometer at temperature of 23°C. A parallel plates module with a diameter of 20mm was used to measure the properties of the resin composites tested. We developed two models to describe the obtained data: the generalized Newton model and the generalized Zener model (the so-called three parameter model). Both models contain fractional derivatives of Riemann-Liouville type. By determining the parameters of the model we were able to fit experimental data with high accuracy. RESULTS: Our results show that flowable "bulk-fill" resin-composite material (SDR) has distinct properties as compared to other two flowable resin composite materials (Revolution Formula 2 and Filtek Ultimate). Thus, previously found SDR properties as "bulk-fill" flowable base results in the fact that it is described by generalized Zener model (i.e., it has properties of solid like viscoelastic material). SIGNIFICANCE: Our model may be used to predict behavior of tested composites in different flow conditions. The SDR has initially small almost constant complex viscosity showing that it has good self-leveling property.