Publications by authors named "Guelnaz Karatay"

Article Synopsis
  • - Perylene monoimide diesters and phenyl-linked bichromophores exhibit strong fluorescence in dilute solutions while generating very few triplet states post-excitation, indicating efficient energy relaxation.
  • - The monomer in solution tends to form non-emissive face-to-face dimers, which upon illumination create a triplet pair with a yield of 13%, and this triplet has a short lifetime of about 80 ps before it decays.
  • - When the concentration increases, self-association happens, especially with the -bridged bichromophore, resulting in reduced triplet formation in solvents like tetrahydrofuran at room temperature.
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Background/aim: The most common and often first metastatic site of colorectal cancer (CRC) is the liver, and radiological modalities have a critical role in the diagnosis of colorectal liver metastasis (CRLM). In this study, the possible relationship between portal vein diameter, number of metastases, and metastasis diameter was evaluated in CRLM patients who underwent computed tomography (CT) examination with intravenous contrast (IV).

Patients And Methods: Cases diagnosed with CRLM who underwent abdominal CT examination with IV contrast between December 2020 and January 2024 were retrospectively scanned.

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<b>Introduction:</b> The main cause of groin pain is inguinal hernia (IH). The most commonly used imaging test for diagnosis is sonography, which is also useful in distinguishing between indirect and direct hernias.<b>Aim:</b> In this study, measurements were made with sonography in the semi-erect position (45) in addition to the supine position and the effectiveness of this position in detecting the defect was investigated.

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Objective: To compare the short-term results of complete mesogastric excision with the conventional surgical technique.

Study Design: An experimental study. Place and Duration of the Study: Department of Gastroenterological Surgery, Health Sciences University, Basaksehir City Hospital, Istanbul, Turkiye, from April to December 2023.

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The current study proposes RBBR biosorption by Clostridium beijerinckii DSMZ 6422 biomass remaining after biobutanol production from pumpkin peel (PP) by a zero-waste approach. Efficient biobutanol production was achieved by investigating initial PP concentrations (5-20% without or with enzymatic hydrolysis) and fermentation time. According to this, the highest concentrations of biobutanol and total ABE were obtained as 4.

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Background: We aim to investigate any possible associations between chemokine receptor expression and responses to neoadjuvant chemotherapy (NAC) along with outcomes in patients with triple-negative breast cancer (TNBC) with locally advanced disease.

Method: Expressions of chemokine receptors were examined immunohistochemically after staining archival tissue of surgical specimens (n = 63) using specific antibodies for CCR5, CCR7, CXCR4, and CXCR5.

Results: Patients with high CCR5, CCR7, CXCR4, and CXCR5 expression on tumors and high CXCR4 expression on tumor-infiltrating lymphocytes (TILs) were less likely to have a pathological complete response (pCR) or Class 0-I RCB-Index compared to others.

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Background And Purpose: Given their overlapping features, pituitary metastases frequently imitate pituitary neuroendocrine tumors in neuroimaging studies. This study aimed to distinguish pituitary metastases from pituitary neuroendocrine tumors on the basis of conventional MR imaging and clinical features as a practical approach.

Materials And Methods: In this 2-center retrospective study, backward from January 2024, preoperative pituitary MR imaging examinations of 22 pituitary metastases and 74 pituitary neuroendocrine tumors were analyzed.

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Context.—: PIT1 and SF1-multilineage pituitary neuroendocrine tumors (PitNETs) have been defined since the classification of adenohypophysial tumors based on the PIT1, SF1, and TPIT transcription factors.

Objective.

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Parkinson's disease (PD) is a neurodegenerative disorder that affects millions of individuals globally. It is characterized by the loss of dopaminergic neurons in Substantia Nigra pars compacta (SNc) and striatum. Neuroimaging techniques such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI) help diagnosing PD.

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A 70-year-old man who was scheduled for surgery because of the recurrence of gastric cancer was referred to our clinic preoperatively. The patient underwent a comprehensive evaluation through 18 F-FDG and 68 Ga-FAPI ( 68 Ga-labeled FAP inhibitors) PET/CT scans. The 68 Ga-FAPI PET/CT scan was particularly valuable in this case because of its ability to detect recurrent mass lesions and identify unusual metastatic sites compared with the 18 F-FDG PET/CT scan.

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Article Synopsis
  • Researchers added MnO nanoparticles to PVP polymer nanofibers to improve their ability to limit light, using different concentrations of the nanoparticles.
  • Scanning Electron Microscopy (SEM) confirmed that the MnO nanoparticles were well integrated into the nanofibers, and increasing their concentration changed the optical characteristics, such as widening the band gap energy.
  • The study found that while higher concentrations of MnO enhanced nonlinear absorption (NA) behavior, it eventually weakened at very high light intensities, indicating a complex interaction of absorption mechanisms that can be useful in optoelectronic applications.
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Fine needle aspiration biopsy (FNAB) guided by ultrasonography is routinely used to identify thyroid nodules prior to surgery. Although FNAB has great diagnostic accuracy and safety, it is limited by its relatively low diagnostic accuracy in follicular lesions, such as non-diagnostic or atypia of unclear significance (AUS)/follicular lesion of uncertain significance (FLUS). Additional diagnostic tests are required to overcome these challenges in evaluating thyroid nodules.

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The effect of aluminum (Al) concentration on the surface plasmon resonance (SPR) band position of aluminum/polyvinylpyrrolidone (Al/PVP) composite nanofibers was investigated to strengthen nonlinear absorption (NLA) and widen its spectral range. With increasing Al content in PVP nanofibers, the SPR band was shifted towards excitation wavelength and an improved NLA response was achieved. The NLA response was examined both experimentally, by conducting -scan experiments, and theoretically, using two models.

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Herein, a spiro rhodamine (Rho)-thionated naphthalimide (NIS) electron donor-acceptor orthogonal dyad (Rho-NIS) was prepared to study the formation of a long-lived charge separation (CS) state the electron spin control approach. The transient absorption (TA) spectra of Rho-NIS indicated that the intersystem crossing (ISC) occurs within 7-42 ps to produce the NIS state the spin orbit coupling ISC (SOC-ISC). The energy order of CS (2.

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Background: Prostate cancer (PC) is the most common type of cancer in elderly men, with a positive correlation with age. As resistance to treatment has developed, particularly in the progressive stage of the disease and in the presence of microfocal multiple bone metastases, new generation radionuclide therapies have emerged. Recently, [Tb], a radiolanthanide introduced for treating micrometastatic foci, has shown great promise for treating prostate cancer.

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Infectious diseases caused by bacteria that have become resistant to antibiotics have increased in prevalence, necessitating new methods for their diagnosis and treatment. The aim of this study was to compare the efficacy of synthetic ciprofloxacin to that of organic ciprofloxacin produced by cave microorganisms, as well as to evaluate the feasibility of using organic ciprofloxacin radiolabeled with technetium-99m as an imaging agent. Organic ciprofloxacin produced by cave bacteria isolated from sediment taken from the dark zone of Antalya's "Yark Sinkhole," (Turkey's 14th deepest cave), was purified using high-performance liquid chromatography.

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This study aims to assess the impact of heat treatment on the emulsifying properties of lentil protein isolate (LPI) dispersion to produce high internal phase emulsions (HIPEs). The heat-treated LPI dispersion was characterized by size, turbidity, solubility, zeta potential, free sulfhydryl group, electrophoresis, differential scanning calorimetry, circular dichroism, Fourier transforms infrared spectroscopy and intrinsic fluorescence. HIPEs were produced with 25% of LPI dispersion (2%, w/w) and soybean oil (75%) using a rotor-stator (15,500 rpm/1 min).

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Objective: Epilepsy is one of the oldest and the most common chronic neurological diseases. Antiepileptic drugs (AEDs) are the backbone of epilepsy treatment. However, epileptogenesis has not been fully elucidated.

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Objective: Pathology in any segment of the spine-pelvis-lower extremity may impair the global postural balance, leading to compensatory alterations in other parts. The aim of this study was to compare the pelvic movements of patients suffering from knee osteoarthritis with patients who underwent total knee arthroplasty and healthy controls.

Methods: This study was performed at the Department of Orthopedics and Traumatology Clinic of a Cankiri State Hospital between April 2021 and February 2022.

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Paired box 1 (PAX1) deficiency has been reported in a small number of patients diagnosed with otofaciocervical syndrome type 2 (OFCS2). We described six new patients who demonstrated variable clinical penetrance. Reduced transcriptional activity of pathogenic variants confirmed partial or complete PAX1 deficiency.

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BODIPY dyes substituted by phenol or -COOMe units at the meso-position (C8) with and without a distyryl group including a methoxy moiety at the -C3 and -C5 positions of the BODIPY have been synthesized to analyze the photophysical properties. To clarify the ground-state interaction, absorption and emission features were investigated in the THF environment. Extending the π-conjugation with the methoxy moiety at -C3 and -C5 positions of BODIPY leads to a spectral shifting of the absorption maxima toward red by 120 nm.

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Background: LPS-responsive beige-like anchor (LRBA) deficiency (LRBA) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA4) insufficiency (CTLA4) are mechanistically overlapped diseases presenting with recurrent infections and autoimmunity. The effectiveness of different treatment regimens remains unknown.

Objective: Our aim was to determine the comparative efficacy and long-term outcome of therapy with immunosuppressants, CTLA4-immunoglobulin (abatacept), and hematopoietic stem cell transplantation (HSCT) in a single-country multicenter cohort of 98 patients with a 5-year median follow-up.

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Bodipy (BDP)-perylenebisimide (PBI) donor-acceptor dyads/triad were prepared to study the spin-orbit charge-transfer intersystem crossing (SOCT-ISC). For BDP-PBI-3, in which BDP was attached at the imide position of PBI, higher singlet oxygen quantum yield (Φ =85 %) was observed than the bay-substituted derivative BDP-PBI-1 (Φ =30 %). Femtosecond transient absorption spectra indicate slow Förster resonance energy transfer (FRET; 40.

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Background: Immune checkpoint inhibition, combined with novel biomarkers, may provide alternative pathways for treating chemotherapy-resistant triple-negative breast cancer (TNBC). This study investigates the expression of new immune checkpoint receptors, including CD155 and CD73, which play a role in T and natural killer (NK) cell activities, in patients with residual TNBC after neoadjuvant chemotherapy (NAC).

Methods: The expression of biomarkers was immunohistochemically examined by staining archival tissue from surgical specimens (n = 53) using specific monoclonal antibodies for PD-L1, CD155, and CD73.

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