İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Red cell distribution width-to-platelet ratio and other hematological markers as early predictors of bronchopulmonary dysplasia in preterm infants
(MDPI Publishing, 2025) Arcagök, Baran Cengiz; Kandemir, İbrahim
Background/Objectives: Bronchopulmonary dysplasia (BPD) frequently affects preterm infants and is associated with lasting morbidity. Early prediction remains challenging. The present study investigated whether hematological inflammatory markers—platelet-to-lymphocyte ratio (PLR), red cell distribution width (RDW), and red cell distribution width-to-platelet ratio (RPR)—can predict the development of BPD in preterm neonates. Methods: We performed a retrospective cohort study involving 100 infants born at less than 32 weeks’ gestation. Complete blood count (CBC) parameters were collected at birth, 72 h, 1 week, and 2 weeks of life. Associations between PLR, RDW, RPR, and BPD development were analyzed. Multivariate regression and receiver operating characteristic (ROC) curve analyses were carried out to evaluate the predictive performance of the markers. Results: Forty-nine percent of infants developed BPD. Those with BPD had significantly higher RDW, PLR, and RPR values, and lower lymphocyte and platelet counts at various time points. Gestational age, respiratory distress syndrome, and hematological indices independently predicted BPD. ROC analysis showed that RDW ≥ 67.2 and PLR ≥ 98.13 at 72 h, and RPR ≥ 0.3 at 7 and 14 days had good predictive performance. A combined scoring system, including clinical and hematological markers, achieved high sensitivity and specificity. Conclusions: Hematological inflammatory markers, especially RPR, PLR, and RDW, derived from routine CBC tests may serve as accessible, cost-effective tools for early BPD risk stratification in preterm infants. Additional studies are needed to confirm these results and better define their relevance in clinical practice.
Anatomical investigation of levator palpebrae superioris muscle and the distribution pattern of oculomotor nerve
(Springer Nature Link, 2025) Nteli Chatzioglou, Gkionoul; Gayretli, Özcan; Özbilen, Kemal Turgay; Önal, Vildan; Coşkun, Osman; Kale, Ayşin
Purpose This study aims to evaluate the morphological features of the levator palpebrae superioris muscle (LPS) and the variations in the distribution of the oculomotor nerve in the muscle. Methods 100 bilateral orbits from 50 cadavers were included in our study. In our study, the medial, lateral, and middle length, width, and thickness of the LPS were measured from 3 different points and recorded. In addition, the number of branches of the oculomotor nerve entering the LPS muscle was calculated. Results The medial, lateral, and middle length of LPS were 34.85±5.30 mm, 34.62±5.67 mm, 35.77±5.31 mm on the right side and 33.66±4.74 mm, 33.81±4.83 mm, 34.54±5.14 mm on the left side, respectively. The width of the muscle was seen to expand from proximally to distally. It was noted that the middle 1/3 thickness of the LPS was the thickest part of the muscle compared to the other parts. A total of 239 oculomotor branches entered the LPS. The middle 1/3 of the LPS was reached by 151 oculomotor nerve branches. It was noted that the largest number of oculomotor nerves entered the middle 1/3 part of LPS. Conclusion The morphometric and morphological findings of LPS and branches of the oculomotor nerve may be useful in surgical planning for the LPS and levator aponeurosis and in preventing complications during surgical interventions.
Diagnostic value of leukocyte count, c-reactive protein, and procalcitonin in pediatric liver transplant patients during the first week postoperative: A longitudinal study from a tertiary center and a new diagnostic method for predicting systemic infection
(MDPI Publishing, 2025) Önal, Zerrin; Türkmen, Elif; Demirkol, Demet; Leblebici, Uğur Can; Kandemir, İbrahim; Yılmaz, Tuğçe Göksu; Torun, Selda Hançerli; Ekiz, Feza; Özden, Ilgın; Durmaz, Özlem
Background/Objectives: Infection is a major complication during the early postoperative period following pediatric liver transplantation (LT). Prompt diagnosis and treatment are essential to prevent death. We aimed to assess the diagnostic value of procalcitonin (PCT), white blood cell count (WBC), and C-reactive protein (CRP) levels for detecting bacterial infection and SIRS within the first week after LT. Methods: Demographic data, vital signs, laboratory results (PCT, CRP, WBC), and culture findings on the 1st, 4th, and 7th days between January 2010 and 2024 were collected retrospectively. Results: The study included 88 patients. Seventy-two percent had cirrhotic liver disease. SIRS was present in 17% (n = 15), and bacterial growth was detected in 20% (n = 18). Bacterial growth was found in 80% of patients with SIRS (n = 12/15) and in 8% of SIRS-negative patients (n = 6/73). PCT levels were significantly elevated on days 1, 4, and 7, and CRP lev els on days 4 and 7 in patients with SIRS. PCT elevation was significant on days 1, 4, and 7, while WBC increase was noted on day 7 in patients with bacterial growth. Body temperature ≥ 37.1 ◦C and PCT ≥ 5.1 ng/dL on the first day together showed a sensitivity of 72.2% and specificity of 84.3% for bacterial growth. Similarly, body temperature ≥ 37.1 ◦C and PCT ≥ 9.2 ng/dL on the first day yielded 73% sensitivity and 95% specificity for diagnosing SIRS. Cirrhotic patients exhibited limited or no WBC response to bacterial growth. Conclusions: PCT, CRP, and WBC alone are insufficient for diagnosing infection. Combined assessment of body temperature changes and PCT elevation may serve as more accurate indicators. Nonetheless, close monitoring of culture results and clinical signs, with serial physical exams, can aid timely infection management or prevent unnecessary antibiotic adjustments.
Energy and exergy analysis of a cycle‑skipping strategy in an HCCI engine fueled with natural gas
(Springer Nature Link, 2025) Atak, Nisa Nur; Tunçer, Erdal; Doğan, Battal; Ünal, Kenan
Homogeneous charge compression ignition (HCCI) engines have attracted considerable interest due to its incorporation of features from both gasoline and diesel engines. In this study, the effects of cycle-skipping strategies on engine perfor mance, efficiency, and emissions in a natural gas-fired HCCI engine were investigated experimentally. Experiments were conducted under constant engine speed, at 25, 50, and 75% load levels, in the Normal, 3 Normal-1 Skip (3N1S), 2 Normal-1 Skip (2N1S), and 1 Normal-1 Skip (1N1S) cycle modes. Emissions, fuel consumption, energy–exergy flow, thermal losses, irreversibilities, entropy generation, thermal, and exergy efficiencies were calculated based on the experimental data. Under 50% engine load, the NOx emission in the 3N1S operating mode was measured at 1594 ppm, whereas it increased by 52.5% to 2431 ppm in the 2N1S mode. The correlation between cycle-skipping tactics and thermal efficiency was determined to be contingent upon engine load. In Normal and 3N1S modes, thermal efficiency generally improves with elevated engine loads, while the 2N1S and 1N1S modes provide superior performance at low to medium loads. At a constant 50% load, heat effi ciency in the 2N1S mode increased by 7.84% to reach 28.34% compared to the Normal mode. Additionally, thermodynamic analyses revealed that the 1N1S mode has the lowest entropy generation and the least irreversibility, at 0.021 kW/K. These results demonstrate that cycle-skipping strategies can be an effective tool for optimizing engine performance based on load.
Investigation of photocatalytic degradation of methyl orange using zinc oxide-supported chitosan hydrogel beads
(Taylor & Francis, 2025) Kaba, İbrahim; Bozkurt, Rabia Nur; Kılıç, Behris
In this study, chitosan-based ZnO supported hydrogels (CZ–H) were synthesized to evaluatetheir photocatalytic degradation performance against methyl orange (MO) dye. The compos-ite hydrogels were characterized using X-ray Diffraction (XRD), UV–Vis DRS, ScanningElectron Microscopy (SEM-EDS), Thermogravimetric Analysis (TGA), and Fourier TransformInfrared Spectroscopy (FTIR). These characterization results confirmed the successful forma-tion of the CZ–H composite structure. The band gap of the composite was approximately2.77 eV, supporting enhanced photocatalytic activity. Photocatalytic experiments showedthat CZ–H removed 74% of MO within 60 min, compared to 42% for pure chitosan beads,with reaction rate constants of 0.0237 min−1 and 0.0113 min−1, respectively. Moreover, theCZ–H beads demonstrated good reusability with minimal loss in efficiency over multiplecycles. These findings highlight the potential of CZ–H as a stable, effective, and reusablephotocatalyst for the efficient removal of dyes from wastewater.
