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Yayın A new method for the source localization in sectionally homogeneous bounded domains involving finitely many inner interfaces of arbitrary shapes(Pergamon-Elsevier Science, 2001-05) İdemen, Mehmet Mithat; Alkumru, AliA new method to localize a static point source buried in a nonhomogeneous bounded domain composed of finitely many homogeneous parts separated by interfaces of arbitrary shapes was established. The source can be a simple point charge or current or a dipole of them. The method requires only the knowledge of the potential function Phi (x, y, z) at five or six points on the outermost interface depending on whether the source is simple or dipole. The new and basic feature of the method consists of determining the potential function Phi (0)(x, y, z) which would be observed if the whole space was filled with a homogeneous material. Then, in the case of a simple source, the position P-0 as well as the strengths can be determined, in general, by solving a system of three linear algebraic equations. When the source consists of a dipole, its position P-0 and moment (p) over right arrow can be found by solving a system of six nonlinear algebraic equations. The determination of Phi (0) P-0 and s (or (p) over right arrow) is achieved iteratively by solving the above-mentioned algebraic equations along with a singular integral equation satisfied by Phi (0) Some illustrative examples show the applicability and accuracy of the method. The method can have effective applications in heat conduction, matter diffusion, electrostatics, steady-state current flow, electroencephalography, electrocardiography, etc.Yayın A novel approach to non-invasive intracranial pressure wave monitoring: a pilot healthy brain study(Multidisciplinary Digital Publishing Institute (MDPI), 2025-06-28) Karaliunas, Andrius; Bartusis, Laimonas; Krakauskaite, Solventa; Chaleckas, Edvinas; Deimantavicius, Mantas; Hamarat, Yasin; Petkus, Vytautas; Stulge, Toma; Ratkunas, Vytenis; Çelikkaya, Güven; Januleviciene, Ingrida; Ragauskas, ArminasIntracranial pressure (ICP) pulse wave morphology, including the ratios of the three characteristic peaks (P1, P2, and P3), offers valuable insights into intracranial dynamics and brain compliance. Traditional invasive methods for ICP pulse wave monitoring pose significant risks, highlighting the need for non-invasive alternatives. This pilot study investigates a novel non-invasive method for monitoring ICP pulse waves through closed eyelids, using a specially designed, liquid-filled, fully passive sensor system named ‘Archimedes 02’. To our knowledge, this is the first technological approach that enables the non-invasive monitoring of ICP pulse waveforms via closed eyelids. This study involved 10 healthy volunteers, aged 26–39 years, who underwent resting-state non-invasive ICP pulse wave monitoring sessions using the ‘Archimedes 02’ device while in the supine position. The recorded signals were processed to extract pulse waves and evaluate their morphological characteristics. The results indicated successful detection of pressure pulse waves, showing the expected three peaks (P1, P2, and P3) in all subjects. The calculated P2/P1 ratios were 0.762 (SD = ±0.229) for the left eye and 0.808 (SD = ±0.310) for the right eye, suggesting normal intracranial compliance across the cohort, despite variations observed in some individuals. Physiological tests—the Valsalva maneuver and the Queckenstedt test, both performed in the supine position—induced statistically significant increases in the P2/P1 and P3/P1 ratios, supporting the notion that non-invasively recorded pressure pulse waves, measured through closed eyelids, reflect intracranial volume and pressure dynamics. Additionally, a transient hypoemic/hyperemic response test performed in the upright position induced signal changes in pressure recordings from the ‘Archimedes 02’ sensor that were consistent with intact cerebral blood flow autoregulation, aligning with established physiological principles. These findings indicate that ICP pulse waves and their dynamic changes can be monitored non-invasively through closed eyelids, offering a potential method for brain monitoring in patients for whom invasive procedures are not feasible.Yayın Investigation of symptom-specific functional connectivity patterns in Parkinson’s disease(Springer-Verlag Italia S.R.L., 2025-06-14) Kıçik, Ani; Bayram, Ali; Erdoğdu, Emel; Kurt, Elif; Sarıdede, Dilek Betül; Cengiz, Sevim; Bilgiç, Başar; Hanağası, Haşmet; Öztürk Işık, Esin; Gürvit, Hakan; Tüzün, Erdem; Demiralp, TamerParkinson’s disease (PD) is a complex neurodegenerative disease, characterized by pronounced heterogeneity in symptoms. This study investigates the functional connectivity (FC) patterns associated with distinct symptom clusters, aiming to elucidate the heterogeneity in PD and uncover the neural mechanisms underlying its motor and cognitive symptoms. Resting-state functional MRI (rs-fMRI) data from 55 non-demented PD patients and 24 healthy controls (HC) were used to perform seed-to-seed FC analyses. A clustering algorithm was applied to the cognitive and motor scores of all PD patients to generate relatively homogeneous symptomatic subgroups. PD patients exhibited a general decrease in FC within a network comprising the sensorimotor network (SMN) and the visual network (VN) regions. Symptom-based clustering revealed three relatively homogeneous subgroups, exhibiting a gradient pattern: patients with greater motor deficits showed significant disconnection within the SMN, whereas patients with greater visuospatial deficits exhibited reduced FC in an extended subnetwork, with pronounced disconnections between the VN and SMN areas. Our study demonstrated a notable disconnection between the SMN and VN, indicating impaired visual-motor integration in PD. Stronger disconnection within the SMN was associated with greater motor dysfunction, and stronger visual-sensorimotor disconnections were associated with greater visuospatial deficits. These findings suggest that at least two separate routes of functional disconnection may be responsible for the inhomogeneous symptom distribution in PD.Yayın Analyzing language ability in first-episode psychosis and their unaffected siblings: a diffusion tensor imaging tract-based spatial statistics analysis study(Elsevier Ltd, 2024-11) Çabuk, Tuğçe; Şahin Çevik, Didenur; Çakmak, Işık Batuhan; Yılmaz Kafalı, Helin; Şenol, Bedirhan; Avcı, Hanife; Karlı Oğuz, Kader; Toulopoulou, TimotheaSchizophrenia (SZ) is a highly heritable mental disorder, and language dysfunctions play a crucial role in diagnosing it. Although language-related symptoms such as disorganized speech were predicted by the polygenic risk for SZ which emphasized the common genetic liability for the disease, few studies investigated possible white matter integrity abnormalities in the language-related tracts in those at familial high-risk for SZ. Also, their results are not consistent. In this current study, we examined possible aberrations in language-related white matter tracts in patients with first-episode psychosis (FEP, N = 20), their siblings (SIB, N = 20), and healthy controls (CON, N = 20) by applying whole-brain Tract-Based Spatial Statistics and region-of-interest analyses. We also assessed language ability by Thought and Language Index (TLI) using Thematic Apperception Test (TAT) pictures and verbal fluency to see whether the scores of these language tests would predict the differences in these tracts. We found significant alterations in language-related tracts such as inferior longitudinal fasciculus (ILF) and uncinate fasciculus (UF) among three groups and between SIB and CON. We also proved partly their relationship with the language test as indicated by the significant correlation detected between TLI Impoverished thought/language sub-scale and ILF. We could not find any difference between FEP and CON. These results showed that the abnormalities, especially in the ILF and UF, could be important pathophysiological vulnerability indexes of schizophrenia. Further studies are required to understand better the role of language as a possible endophenotype in schizophrenia with larger samples.Yayın Effects of laurocerasus officinalis roem (Cherry Laurel) on cognitive function and neurobiochemical pathways in a streptozotocin-induced nontransgenic Alzheimer's disease model(Multidisciplinary Digital Publishing Institute (MDPI), 2026-03-08) Özsoy, Fulya; Yanar, Karolin; Sayılı, Uğurcan; Atukeren, Pınar; Uzun, HafizeBackground: This study investigated the effects of Laurocerasus officinalis Roem (cherry laurel; CL), a traditionally consumed fruit, on cognitive performance and selected neurobiochemical and metabolic pathways in a nontransgenic streptozotocin (STZ)-induced Alzheimer’s disease (i.c.v. STZ) model and an STZ-induced type 2 diabetes mellitus (T2DM; i.p. STZ) model. Method: Fifty-seven adult male Sprague–Dawley rats were allocated to control, T2DM, and Alzheimer (ALZ) model groups, with subgroup interventions including CL supplementation and, in the T2DM model, metformin as a comparator. Spatial learning and memory were assessed using the Morris Water Maze. Serum and brain tissue levels of GSK3-β, glutathione (GSH), interleukin-1 (IL-1), GLUT4, GLP-1, β-amyloid (Aβ), and acetylcholinesterase (AChE) were quantified. Results: Serum GSK3-β levels did not differ significantly between groups, whereas brain tissue GSK3-β showed significant between-group differences. CL increased GSH levels in both models, with significant elevations in serum and brain tissue GSH in the ALZ model following CL administration; in the T2DM model, GSH increased after both CL and metformin. In the ALZ model, CL was associated with decreased serum Aβ and AChE levels and improved Morris Water Maze performance, reflected by reduced escape latencies. Conclusions: CL supplementation was associated with antioxidant enhancement and modulation of amyloid- and cholinergic-related measures, alongside improved spatial learning performance in the STZ-induced nontransgenic ALZ model. In addition, CL reduced blood glucose in the T2DM model. Given the likely contribution of fruit phytochemicals (including total phenolics), further studies are warranted to better define the bioactive composition and mechanisms underlying these effects.
