Electrografting and Surface Properties of Some Substituted Nitrophenols on Glassy Carbon Electrode and Simultaneous Pb²⁺ - Cd²⁺ Analysis via Assist of Graphene Oxide Terminated Surface

Erkal, Aslı,Erdoğ,an, Mehmet Selç,uk,Aş,ık, İ,hsan,Ekş,i, Haslet,Jeon, Seungwon,Solak, Ali Osman,Ü,stü,ndağ,, Zafer The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.10

<P>A new electrode was prepared by the electrooxidation of orto-, meta-, and para-substituted nitro phenols on glassy carbon electrode. Electrochemical modification of the electrodes was carried out in 0.01 M HCl using cyclic voltammetry (CV). Then nitro groups in the covalently grafted nitro phenol derivatives on GC electrode were reduced to amine groups in 0.01 M HCl. The electrochemical behavior of the modified electrodes was studied in the presence of electroactive redox probes such as ferrocene and ferricyanide by CV and electrochemical impedance spectroscopy (EIS). X-ray photoelectron spectroscopy (XPS) was employed to characterize the surface structure and composition of the modified substrates. Thickness of the films was measured by using an ellipsometer. Surface topography of the nanofilms and bare GC was characterized via AFM. Graphene oxide (GO) was covalently attached on 4-aminophenyl involved surface through EDC. Simple immersing of the GO covered nanoplatform into a sample solution led to the chemical deposition by means of the interaction with Cd<SUP>2+</SUP> and Pb<SUP>2+</SUP> ions, simultaneously. Various analysis parameters that affect the simultaneous analysis of the ions such as deposition time, pH factor and deposition temperature, were optimized. Calibration curve for the GO grafted electrode surface with Square-wave anodic stripping voltammetry (SWASV) were obtained in the concentration range between 1 × 10<SUP>−8</SUP> M and 1 × 10<SUP>−12</SUP> M for Pb<SUP>2+</SUP> and Cd<SUP>2+</SUP>. The detection limits of the modified electrode for Pb<SUP>2+</SUP> and Cd<SUP>2+</SUP> ions were determined to be about 3.2 (± 0.1) × 10<SUP>−13</SUP> M and 2.4 (± 0.2) × 10<SUP>−13</SUP> M, respectively.</P>

A Prognostic Marker in Idiopathic Sudden Sensorineural Hearing Loss: Serum Calprotectin

İhsan Kuzucu,Tuba Çandar,Deniz Baklacı,İsmail Güler,Rauf Oğuzhan Kum,Hande Arslan,Müge Özcan 대한이비인후과학회 2020 Clinical and Experimental Otorhinolaryngology Vol.13 No.1

Objectives. Calprotectin, a protein released by neutrophils, has been used in many studies as a biomarker showing the presence of inflammation. In this study, it was aimed to investigate the relationship between serum calprotectin level and response to the treatment of idiopathic sudden sensorineural hearing loss (ISSHL). Methods. The present study is a prospective, cross-sectional historical cohort study. The study group consisted of 44 patients with ISSHL, and the control group consisted of 41 healthy volunteers without ear pathology. At the same time, patients in the study group were divided into three groups according to the response to ISSHL treatment (recovered, partially recovered, unrecovered). The relationship between the groups was statistically evaluated in terms of serum calprotectin levels. Results. The mean serum calprotectin value was 75.67±19.48 ng/mL in the study group and 50.24±29.14 ng/mL in the control group (P=0.001). Serum calprotectin value according to the severity of hearing loss in the mild, moderate and severe was 66.20±8.82, 70.35±16.77, and 91.23±19.73 ng/mL, respectively. Serum calprotectin value in the severe group was significantly higher compared to the moderate and mild groups (P=0.004, P=0.001, respectively). Serum calprotectin value according to the treatment response in the recovered, partially recovered and unrecovered groups was 63.36±11.54, 80.17±12.06, and 85.33±22.33 ng/mL, respectively. Serum calprotectin value in the recovered group was significantly lower compared to the partially recovered and unrecovered groups (P=0.002, P=0.001, respectively). Conclusion. Serum calprotectin value informs the clinician about both the severity of hearing loss and the response to treatment. Hence, serum calprotectin can be used as an important biomarker in ISSHL patients for the determination of the prognosis of disease.

Geopolymer concrete with high strength, workability and setting time using recycled steel wires and basalt powder

Ali İhsan Çelik,Yasin Onuralp Özkılıç 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.5

Geopolymer concrete production is interesting as it is an alternative to portland cement concrete. However, workability, setting time and strength expectations limit the sustainable application of geopolymer concrete in practice. This study aims to improve the production of geopolymer concrete to mitigate these drawbacks. The improvement in the workability and setting time were achieved with the additional use of NaOH solution whereas an increase in the strength was gained with the addition of recycled steel fibers from waste tires. In addition, the use of 25% basalt powder instead of fly ash and the addition of recycled steel fibers from waste tires improved its environmental feature. The samples with steel fiber ratios ranging between 0.5% and 5% and basalt powder of 25%, 50% and 75% were tested under both compressive and flexure forces. The compressive and flexural capacities were significantly enhanced by utilizing recycled steel fibers from waste tires. However, decreases in these capacities were detected as the basalt powder ratio increased. In general, as the waste wire ratio increased, the compressive strength gradually increased. While the compressive strength of the reference sample was 26 MPa, when the wire ratio was 5%, the compressive strength increased up to 53 MPa. With the addition of 75% basalt powder, the compressive strength decreases by 60%, but when the 3% wire ratio is reached, the compressive strength is obtained as in the reference sample. In the sample group to which 25% basalt powder was added, the flexural strength increased by 97% when the waste wire addition rate was 5%. In addition, while the energy absorption capacity was 0.66 kN in the reference sample, it increased to 12.33 kN with the addition of 5% wire. The production phase revealed that basalt powder and waste steel wire had a significant impact on the workability and setting time. Furthermore, SEM analyses were performed.

An Investigation of the Volatile Compound Profiles of Probiotic Yogurts Produced Using Different Inulin and Demineralised Whey Powder Combinations

Arzu Kavaz Yüksel,İhsan Bakırcı 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.3

Volatile compound profiles of probiotic yogurt samples prepared using 8 different prebiotic combinations were analyzed using gas chromatography/mass spectrometry (GC-MS) with solid phase micro extraction during 28 days of storage. A total of 40 volatile compounds were identified in yogurt samples during storage consisting of 2 aldehydes, 6 ketones, 4 alcohols, 6 acids, 5 esters, 3 terpenes, 3 aromatic hydrocarbons, and 12 aliphatic hydro-carbons. Acetaldehyde, diacetyl, acetoin, 2-heptanone, ethanol, isoamyl alcohol, acetic acid, caproic acid, caprilic acid, and capric acid were the major volatile compounds in all probiotic yogurt samples.

Decreased Expression of α-Synuclein, Nogo-A and UCH-L1 in Patients with Schizophrenia: A Preliminary Serum Study

Ömer Faruk Demirel,İhsan Cetin,Şenol Turan,Tarık Sağlam,Nazım Yıldız,Alaattin Duran 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.3

Objective: α-synuclein, Nogo-A and Ubiquitin C-terminal hydrolase L1 (UCH-L1) have neuromodulatory roles for human brain. Therefore, abnormalities of these molecules are associated with neuropsychiatric disorders. Although some serum studies in the other disorders have been made, serum study of α-synuclein, Nogo-A and UCH-L1 is not present in patients with schizophrenia and healthy controls. Therefore, our aim was to compare serum levels of α-synuclein, Nogo-A and UCH-L1 of the patients with schizophrenia and healthy controls. Methods: Forty-four patients with schizophrenia who is followed by psychotic disorders unit, and 40 healthy control were included in this study. Socio-demographic form and Positive and Negative Syndrome Scale (PANSS) was applied to patients, and sociodemographic form was applied to control group. Fasting bloods were collected and the serum levels of α-synuclein, Nogo-A and UCH-L1 were measured by ELISA method. Results: Serum α-synuclein [patient: 12.73 (5.18–31.84) ng/mL; control: 41.77 (15.12–66.98) ng/mL], Nogo-A [patient: 33.58 (3.09–77.26) ng/mL; control: 286.05 (136.56–346.82) ng/mL] and UCH-L1 [patient: 5.26 (1.64–10.87) ng/mL; control: 20.48 (11.01–20.81) ng/mL] levels of the patients with schizophrenia were significianly lower than healthy controls (p<0.001). Conclusion: Our study results added new evidence for explaining the etiopathogenesis of schizophrenia on the basis of neurochemical markers.

Lymphangiectatic Variant of Low Grade Malignant Eccrine Spiradenoma

Gizem Akkas Akgun,Anvar Ahmedov,Ali İhsan Parlar,Mehmet Hüseyin Metineren,Ayse Nur Deger 대한피부과학회 2023 Annals of Dermatology Vol.35 No.1

Low-grade malignant eccrine spiradenoma (spiradenocarcinoma) is a rare sweat glandtumor, which usually arises from a pre- existing benign eccrine spiradenoma. This paperpresents the case of a 55-year-old male who had a lesion in his right elbow for 10 years. Themicroscopic examination revealed a well-demarcated, multilobulated tumor in the dermisand subcutis, which presented with many blood-filled vessels and extensive hemorrhage. The tumor was composed of hyperchromatic, round to oval cells with nucleolar prominence,mild to moderate atypia, and increased mitotic index. Additionally, lymphangiectaticappearance was observed in areas with prominent stromal lymphedema. P53 and Ki-67 hadhigh positivity. Surgical excision of the lesion was performed with adequate surgical margins,and the dissected lymph nodes in the axilla were tumor-negative. After 15 months offollow-up, there was no recurrence or distant metastasis.

Bilateral Optic Disc Drusen Mimicking Papilledema

Alparslan Şahin,Abdullah Kürşat Cingü,Şeyhmus Ari,Yasin Çinar,İhsan Çaça 대한신경과학회 2012 Journal of Clinical Neurology Vol.8 No.2

Background Optic disc drusen, which are calcified deposits that form anterior to the lamina cribrosa in the optic nerve, may mimic papilledema. Case Report We report herein three cases referred to us with suspicion of disc swelling and papilledema. Following ophthalmologic evaluation with B-scan ultrasound, red-free fundus photography, and computed tomography, the diagnosis of papilledema was excluded in all cases and optic disc drusen was diagnosed. Conclusions Clinical suspicion of optic disc drusen in cases presenting with swelling of the optic nerve head is important in order to avoid unnecessary interventions and anxiety. The reported cases highlight the commonly encountered clinical presentations and the practical aspects of diagnosis and management of optic disc drusen.

Reduced-Dose Systemic Fibrinolysis in Massive Pulmonary Embolism: A Pilot Study

Aykan Ahmet Çağrı,Gökdeniz Tayyar,Gül İlker,Kalaycıoğlu Ezgi,Karabay Can Yücel,Boyacı Faruk,Hatem Engin,Weingart Scott D.,Dursun İhsan 대한응급의학회 2023 Clinical and Experimental Emergency Medicine Vol.10 No.3

Objective: Severe pulmonary embolism (PE) has a high mortality rate, which can be lowered by thrombolytic therapy (TT). However, full-dose TT is associated with major complications, including life-threatening bleeding. The aim of this study was to explore the efficacy and safety of extended, low-dose administration of tissue plasminogen activator (tPA) on in-hospital mortality and outcomes in massive PE. Methods: This was a single-center, prospective cohort trial at a tertiary university hospital. A total of 37 consecutive patients with massive PE were included. A peripheral intravenous infusion was used to administer 25 mg of tPA over 6 hours. The primary endpoints were in-hospital mortality, major complications, pulmonary hypertension, and right ventricular dysfunction. The secondary endpoints were 6-month mortality and pulmonary hypertension and right ventricular dysfunction 6 months after the PE. Results: The mean age of the patients was 68.76±14.54 years. The mean pulmonary artery systolic pressure (PASP; 56.51±7.34 mmHg vs. 34.16±2.81 mmHg, P<0.001) and right/left ventricle