İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
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Güncel Gönderiler
Neural approximation of fuzzy gain-scheduled PID control for a dual-crank strandbeest walking mechanism
(IEEE, 2026) Coşkun, Yusuf; Özyılmaz, Lale
This study presents a simulation-based comparison of PID, Fuzzy-PID, and artificial neural network (ANN)-assisted gain-scheduled PID controllers for a modular dual-motor Strandbeest walking mechanism. The mechanism was designed in SolidWorks and transferred to MATLAB/Simscape Multibody, where each leg group is driven by an independent crank and the crank angle is controlled through a joint torque actuator. The ANN is not used as a stand-alone controller; instead, it provides a smooth approximation of the fuzzy gain-scheduling map used in the Fuzzy-PID controller. The controllers are evaluated under step, sinusoidal, disturbance-rejection, and square-wave reference scenarios. The ANN approximated the fuzzy gain map with coefficients of determination of 0.99, 0.92, and 0.83 for the proportional, integral, and derivative gains, respectively. The ANN-assisted controller reduced tracking error in the sinusoidal, square-wave, and disturbance cases, while the Fuzzy-PID controller achieved the lowest stepresponse overshoot. The results show that neural approximation can provide a computationally simple and smooth gain-scheduling structure for simulation-based crank-angle control, although it should not be interpreted as an exact closed-loop reproduction of the original Fuzzy-PID controller.
A 12-week randomized controlled trial of the dietary approaches to stop hypertension (DASH) diet in seropositive rheumatoid arthritis: Effects on disease activity and outcomes
(Elsevier, 2026) Özüpek, Gökçen; Altay, İkbal Süheyla; Kalyoncu Atasoy, Zeynep Begüm; Torun, Ege Sinan
Background & aims: Dietary interventions may improve rheumatoid arthritis (RA) outcomes through anti-inflammatory and metabolic pathways. This study aimed to evaluate the effects of the Dietary Approaches to Stop Hypertension (DASH) diet on disease activity and treatment outcomes in patients with seropositive RA. Methods: In this 12-week parallel-group randomized controlled trial, 82 patients with seropositive RA were randomly assigned to a DASH diet intervention (n = 40) or a control group maintaining their usual diet (n = 42). The primary outcome was change in disease activity assessed using the Disease Activity Score in 28 joints based on erythrocyte sedimentation rate (DAS-28 E SR). Secondary outcomes included change in DAS-28 based on C-reactive protein (DAS-28 CRP), as well as tender and swollen joint counts, ESR, CRP, visual analogue scale (VAS) scores for pain and general health, the Health Assessment Questionnaire (HAQ), and the Short Form-36 (SF-36). Adherence to the intervention was evaluated using the DASH diet score. Assessments were performed at baseline and at weeks 4, 8, and 12. Data were analyzed according to the intention-to-treat principle. Repeated clinical outcomes were analyzed using robust mixed ANOVA or generalized estimating equations (GEE), as appropriate. Results: Of the 82 randomized patients, 49 completed the 12-week study. Adherence to the DASH diet increased significantly in the intervention group compared with the control group (p < 0.001). From baseline to Week 12, DAS-28 ESR decreased by 0.92 points in the DASH group versus 0.17 points in the control group, corresponding to a 0.75-point greater reduction (group × time interaction, p = 0.001). Significant between-group differences in change were also observed for DAS-28 CRP (− 0.62), ESR (− 3.90 mm/h), VAS-pain (− 2.19), VAS-general health (− 2.12), and HAQ (− 0.38) (all group × time p˂0.05). For SF-36, significant between-group differences in change were observed for physical functioning (+10.15), role-physical (+47.30), bodily pain (+22.17), vitality (+18.52), role-emotional (+38.61), and mental health (+12.06) (all group × time p < 0.05). CRP, tender and swollen joint counts did not show significant group × time interactions (p > 0.05). Furthermore, in the intervention group, improvements in DASH diet adherence were negatively correlated with changes in DAS-28 ESR and DAS-28 CRP scores (both p < 0.05). Conclusions: A 12-week DASH dietary intervention may provide clinically meaningful improvements in disease activity and patient-reported outcomes in patients with seropositive RA. These findings support the potential role of the DASH dietary pattern as a promising dietary approach to complement the management of RA. However, the relatively high attrition rate should be considered when interpreting the findings. Trial registration: This trial is registered with Clinicaltrials.gov (ID: NCT07170033). https://clinicaltrials.gov/study/NCT07170033
Optimization of diclofenac sodium-loaded alginate microparticles: Chitosan-assisted encapsulation and ph-dependent release
(MDPI Publishing, 2026) Asgarova, Kamala; Toprakçı, İrem; Bozkurt, Rabia Nur; Kurtulbaş, Ebru; Çağatay, Barış; Şahin, Selin
Alginate microparticles offer a simple approach for drug encapsulation. However, their performance depends on formulation conditions. Diclofenac sodium (DCF) was encapsulated in alginate microparticles by ionic gelation. Sodium alginate concentration, CaCl2 concentration and hardening time were optimized by Response Surface Method (RSM) using Box–Behnken design (RSM-BBD). Encapsulation efficiency (EE) varied considerably with the formulation conditions. The model showed a good fit (R2 = 0.9685), while CaCl2 concentration was the main factor affecting EE. The optimum conditions were 1.91% (w/v) sodium alginate, 4.99% (w/v) CaCl2 and 23.4 min hardening time. The experimental EE was 80.34%, close to the predicted value of 80.41%. Chitosan was added to the optimized formulation at concentrations of 0.10–0.20% (w/v). EE increased with chitosan concentration and reached 93.85% at 0.20%. Drug release was studied in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The release data were evaluated using zero-order, first-order, Higuchi and Korsmeyer–Peppas models. Characterization revealed a transition from a predominantly lamellar and fissured surface in the optimized alginate formulation to a more granular and highly textured architecture following chitosan incorporation, while the released fractions exhibited distinct hydrodynamic and electrokinetic characteristics. The addition of a low amount of chitosan therefore increased DCF encapsulation and changed its release behavior under gastrointestinal conditions.
Clinicopathological features and oncological outcomes in breast cancer presenting with nipple discharge
(Springer Nature Link, 2026) Mollavelioğlu, Baran; Özgen, Atılay; Özgen, Ecem Hazal; Bender, Ömer; Balcı, Fatih Levent; Erözgen, Fazilet; Emiroğlu, Selman; Tükenmez, Mustafa; Yılmaz, Ravza
Background Nipple discharge may indicate subareolar or nipple–areola complex (NAC) involvement in nipple discharge-associated breast cancer, which has important implications for surgical planning and prognosis. This study aimed to analyze the clinicopathological features, radiological findings, and oncological outcomes of breast cancer patients presenting with nipple discharge. Methods Patients who presented with nipple discharge and underwent surgery with a histopathological diagnosis of breast cancer between January 2005 and January 2020 at three tertiary referral centers were retrospectively reviewed. Demographic, clinical, radiological, and pathological data were collected. Demographic, clinical, radiological, and pathological data were retrospectively collected. Results A total of 205 patients were included. Of those, 71.8% presented with bloody discharge. Most patients had early-stage disease (pTis/T1: 78.8%). Overall, pathological NAC involvement was identified in 26.5% of cases, whereas it was estimated as 34.5% in mastectomy cases, and 60% in patients with MRI-suspicious find ings and 48.7% in those with a non-luminal pathology. MRI demonstrated the highest diagnostic accuracy (AUC 0.756, p < 0.001) for detecting NAC involvement independent predictors of NAC involvement were non-luminal subtype (OR 3.15, 95% CI, p = 0.004) and retroareolar mass (OR 2.57, 95% CI, p = 0.012). At a median follow-up of 68 months, locoregional and distant recurrence rates were 2.9% and 9.3%, respectively. No significant differ ences in disease-free or disease-specific survival were observed between patients undergoing breast-conserving surgery and those treated with mastectomy, or between patients with and without NAC involvement. Lympho vascular invasion and nodal positivity were associated with reduced DFS. Conclusion Breast cancers associated with nipple discharge are most often diagnosed at an early stage. Careful clinical and radiological evaluation of nipple–areola complex (NAC) involvement is essential in these patients due to the high NAC involvement in clinical and imaging suspicious cases and aggressive tumor biology. When NAC involvement is excluded, breast-conserving surgery and nipple-sparing mastectomy can be considered in appropriately selected patients, with comparable oncological outcomes.
Uterus-preserving laparoscopic lateral suspension provides durable anatomical and functional success in apical pelvic organ prolapse: Long-term results from a single-center study
(Via Medica, 2026) Şahin, Turan; Tekin, Arzu Bilge; Şahin, Hanifi; Tuğ, Niyazi; Perkyürek, Şahin; Doğan, İlker Orhan
Objectives: To evaluate the long-term anatomical, functional, and patient-reported outcomes of uterus-preserving laparoscopic lateral suspension (LLS) in women with apical pelvic organ prolapse (POP). Material and methods: This retrospective cohort study included 98 women with symptomatic apical POP who underwent uterus-preserving LLS between January 2018 and December 2021 at a single tertiary center. All patients had at least 24 months of follow-up (mean: 40.6 ± 10.8 months). Anatomical outcomes were assessed using the POP-Q system, functional outcomes with POP-SS, P-QOL, M-ISI, and FSFI, and patient satisfaction with the PGI-I scale. The primary endpoint was composite clinical success, defined as anatomical success (POP-Q stage 0–1 in all compartments), absence of reoperation, and a positive PGI-I response. Results: The mean age was 48.1 ± 10.5 years, mean BMI was 27.0 ± 3.5 kg/m², and 42.9% were postmenopausal. Concomitant procedures were performed in 44.9% of cases. At long-term follow-up, significant improvements were observed in all POP-Q points (Ba from 0.6 to –3.4 cm, C from 0.3 to –2.5 cm, and Bp from –1.7 to –3.6 cm; all p < 0.001). POP-SS, P-QOL, and M-ISI scores improved markedly (all p < 0.001). FSFI showed significant improvement in the pain domain. Composite clinical success was achieved in 93.9% of patients, with anatomical success rates of 98.0% (apical), 98.0% (anterior), and 96.9% (posterior). Patient satisfaction was high, with 96.9% reporting “very much better” or “much better” on PGI-I. Reoperation was required in 3.1% of cases. Intraoperative complications included bladder injury (2.0%) and bleeding requiring transfusion (1.0%). Late complications were rare, with mesh exposure in 2.0% and dyspareunia in 3.1%. Conclusions: Uterus-preserving LLS provides durable long-term anatomical and functional success, high patient satisfaction, and low complication rates, representing a safe and effective alternative to sacrocolpopexy in the surgical management of apical POP.
