Marmara University
  • Istanbul, Turkey
Recent publications
An extensive literature providing information on published materials in machine learning exists. However, machine learning is still a rather new concept in the fields of economics and econometrics. This study aims to identify different properties of published documents about machine learning in economics and econometrics and therefore to draw a detailed picture of recent publications from bibliometric analysis perspectives. For the aim of the study, the data are collected from the publications indexed by Web of Science and Scopus databases from the period 1991 to 2020. Inthe study, the data have been illustrated by VOSviewer for science mapping. The analysis of variance has also been used to identify the links between the number of citations of articles and years. The findings obtained provides information about the studies on machine learning in the relevant field conducted in the past, as well as providing an opportunity to gain knowledge about the researched area by shedding light on what the future research areas would be. There is no doubt that it attracts attention has increased significantly on machine learning in the field of economics and econometrics and academic publications on machine learning in the relevant field have increased over the last decade.
Introduction Various online platforms, such as YouTube, are used for surgical education. Esophageal surgery is sophisticated and surgical videos may help reduce the time it takes for surgeons to learn these complicated operations. There is no clear consensus regarding the quality and reliability of esophagectomy videos on YouTube. We aimed to evaluate esophageal surgery videos published on YouTube in terms of quality and reliability. Methods The keywords “esophagectomy” and “surgery” were both searched on YouTube and the first 150 results were evaluated. Eighty two videos were included in the analysis. The quality and reliability of the videos were determined using the esophagectomy scoring system (ESS) developed by the authors, the Journal of the American Medical Association benchmark criteria, and the video power index. Results A total of 82 videos were reviewed. About two-thirds of the videos demonstrated the Ivor Lewis technique and included surgeries performed using the thoracoscopic/laparoscopic method. The videos were analyzed as per the source of the upload: academic (25.7%), industry-sponsored (9.7%), or individual (64.6%). When the scores were compared by the origin of the videos, industry-sponsored videos scored significantly higher than the videos produced by individuals and academic centers (P = 0.01). While the ESS and Journal of the American Medical Association benchmark criteria scores were significantly correlated (P = 0.00), no correlation was found between video length, video power index score, and ESS score. Conclusions Conducting a professional evaluation of videos before they are published on YouTube may enhance video quality. Moreover, valuable videos of better quality can be produced by improving the ESS and by assessing more videos.
Non-peripherally tetra-2,6-dimethoxyphenoxy substituted Co(II) 3, Fe(II) 4, Mn(III) 5, and Ni(II) 6 phthalocyanines were prepared by refluxing the n-pentanol solution of their metal-free analogue H2Pc 2, (obtained by using 3-(2,6-dimethoxyphenoxy)phthalonitrile), metal salts (Co(CH3COO)2.4 H2O, Fe(CH3COO)2, Mn(CH3COO)2.4 H2O or NiCl2) and 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) as the catalyst under N2 atmosphere for 2 h. The molecular structure of metallophthalocyanines 3–6 were explained by common methods which are elemental analysis, MALDI-TOF mass, FTIR, and UV-Vis spectroscopies. The complexes are well dissolved in various solvents (dichloromethane, tetrahydrofuran, dimethylsulfoxide, dimethylformamide, and toluene. Electrochemical redox, electrocatalytic oxygen reducing and electrocolorimetric properties of the phthalocyanine complexes were also measured by voltammetric and in situ UV-Vis spectroelectrochemical techniques. The phthalocyanine complexes displayed highly reversible sequential one-electron redox processes occurring at metal and/or phthalocyanine ring. The association of these processes with net colour changes pointed out their functionality as electrochromic material. Furthermore, the phthalocyanine complexes 3-5 and especially Fe(II)Pc 4, showed striking electrocatalytic oxygen reducing activity, owing to the metal centres with redox activity, increasing their interplay with the O2 molecule.
The electricity network of a country is in continuous development, including the distribution transformers that provide power within a city. Efficient electricity networks depend on the good implementation of the principles of network planning and development. Moreover, technology development and the increasing standard of living are creating greater electricity demand. Besides, housing developments alter the need for electricity in an urban area and will require changes to control load density, adjustment of the voltage on distribution lines, installation of new lines and substations, and restructuring of existing ones. This study develops new mathematical and geometric methods that can be applied to all Low Voltage distribution networks to investigate load distribution, the effects of change and, provide a tool for distribution network planning. The analysis included the electrical power values to the new transformer, the shortest distribution routes between the transformers, and the costs, and provided optimum locations for new transformers. In this way, distribution network planning has been approached with a new method.
Sustainability is, nowadays, a full demand of global community due to the widespread information about hazardous effects of man‐made products, their effluents load eluted after their synthesis and application. Now, the people are looking everywhere to find the green products in all walks of life, such as pharmaceuticals, textiles, flavors, fashions, electronics, etc., due to their excellent ayurvedic and biological nature. Among these products, antiviral, antioxidant and antifungal‐based plant‐derived biocolorants are gaining their revival in such applied fields, particularly in textiles and pharmaceuticals. Of these natural colors, flavonoid‐based natural colorants cover the full spectrum of colors with their beautiful look. In this chapter, various types of flavonoids have been discussed, where their sources have been narrated from isolation to applications. This chapter will provide a brief overview for those who want to use flavonoid‐based colorants in all walks of life.
Background Although several renal biopsy registry reports have been published worldwide, there are no data on primary glomerular disease trends in Turkey. Methods Three thousand eight-hundred fifty-eight native kidney biopsy records were assessed in the Turkish Society of Nephrology Primary Glomerulopathy Working Group (TSN-GOLD) Registry. Secondary disease and transplant biopsies were not recorded in the registry. These records were divided into four periods, before 2009, 2009 to 2013, 2013–2017, and 2017–current. Results A total of 3858 patients (43.6% female, 6.8% elderly) were examined. Nephrotic syndrome was the most common biopsy indication in all periods (58.6%, 53%, 44.1%, 51.6%, respectively). In the whole cohort, IgA nephropathy (IgAN) (25.7%) was the most common PGN with male predominance (62.7%), and IgAN frequency steadily increased through the periods (× 2 = 198, p < 0.001). MGN was the most common nephropathy in the elderly (> 65 years), and there was no trend in this age group. An increasing trend was seen in the frequency of overweight patients (× 2 = 37, p < 0.0001). Although the biopsy rate performed with interventional radiology gradually increased, the mean glomeruli count in the samples did not change over the periods. Conclusions In Turkey, IgAN is the most common primary glomerulonephritis, and the frequency of this is increasing.
This study aimed to evaluate the autonomic dysfunction as assessed by the Composite Autonomic Symptom Score-31 (COMPASS-31) as well as its relationship with disease activity and cardiovascular risks in patients with psoriatic arthritis (PsA). This cross-sectional observational study involved 118 PsA patients (85 females, mean age 45.6 years) and 64 healthy subjects. Cardiovascular risks were recorded including body mass index (BMI), hypertension (HT), diabetes mellitus (DM), dyslipidemia, metabolic syndrome (MetS), and 10-year Framingham Risk scores (FRS) were calculated. PsA was assessed with regard to disease activity, quality of life, and function. Autonomic dysfunction was evaluated using the COMPASS-31 consisting of six subdivisions including orthostatic, vasomotor, secretomotor, gastrointestinal, bladder, and pupillomotor functions. The mean disease duration was 63.3 months. The mean total COMPASS-31 score was significantly higher in PsA patients than in controls (24.4 vs 11.1; p < 0.001), as were all sub-domain scores. COMPASS-31 scores were significantly lower in patients with DAPSA-REM and MDA. The COMPASS-31 total score showed significant correlations with scores of pain, global assessment, fatigue, function, quality of life, DAPSA, and BASDAI (p < 0.05).The presence of HT, dyslipidemia, MetS, and abdominal obesity did not significantly affect the total COMPASS-31 and sub-domain scores, except for the secretomotor scores being significantly higher in patients with abdominal obesity and MetS (p < 0.05). COMPASS-31 scores were not significantly different across the FRS risk groups. The symptoms of autonomic dysfunction are prevalent in PsA patients. High disease activity and pain have negative effects on autonomic function, and also functional impairment, fatigue, and poor quality of life are associated with autonomic dysfunction. However, the COMPASS-31 was found to be insufficient to demonstrate a clear relationship between autonomic dysfunction and cardiovascular risk.
Increased antibiotic use worldwide has become a major concern because of their health and environmental impacts. Since most antibiotic residues can hardly be removed from wastewater using conventional treatments, alternative methods receive great attention. Adsorption is one of the most efficient and cost-effective treatment methods for antibiotics. Among the adsorbents, clay minerals have garnered increasing attention due to their unique properties including availability, high specific surface area, low cost, cation exchange capacity, and good removal efficiency. This paper reviews the recent progress made in the use of natural and modified clay minerals for the removal of antibiotics from water. First, the sources, occurrence, removal and health effects of the antibiotics commonly encountered in water bodies are described. Antibiotic concentration levels and average removal efficiencies measured in conventional activated sludge treatment systems worldwide are also provided to better address the problem. Second, the review explores the characteristics of clay minerals as adsorbent of antibiotics and the factors affecting the adsorption. The review identifies and discusses the future trends and strategies used to increase the adsorption capacity of clay minerals by modification and combination techniques (intercalation of novel functional groups such as organocations, biopolymers and metal pillared-clay minerals, combination with biochar or thermal activation). The quantitative comparisons of clay minerals’ ability for antibiotic removal are given. Some natural clay minerals have good removal potential for antibiotics, with maximum adsorption capacities over 100 mg/g. For most other adsorbents, surface modifications and combination techniques resulted in improved adsorption properties (including higher surface area, enhanced adsorption capacity, increased stability and mechanical strength). Finally, the application of these adsorbents at pilot scale, using real wastewater samples, their reuse, economic analysis and life cycle assessment are other issues that have been considered.
This study was designed to investigate whether Petroselinum crispum (PC) extract has protective effects on the brain in the scopolamine-induced Alzheimer’s disease (AD) rat model. The rats were divided into; control, scopolamine (1 mg/kg, i.p.), galantamine (1.5 mg/kg, i.p.) and PC extract (2 g/kg, p.o.)-treated scopolamine groups. On day 14, the novel object recognition test (NORT) and Morris water maze test (MWMT) were performed and then the rats were sacrificed. Scopolamine-induced cognitive impairments observed in the NORT and MWMT, significantly improved with PC extract and galantamine treatments. Scopolamine reduced M1 receptor expression, Bcl-2/Bax ratio, and glutathione levels in the hippocampus and frontal cortex, while malondialdehyde levels, caspase-3/9 expressions, and acetylcholinesterase (AChE) activity were found to be increased. On the other hand, PC and galantamine treatments reversed these changes. In conclusion, PC extract has shown an ameliorative effect on the spatial and recognition memory, M1 receptor expression, apoptosis, oxidative stress, and increased AChE activity. Thus, it was concluded that PC could prevent AD-like conditions and can be used as a functional food. However, since animal models do not completely mimic those of humans, based on the data obtained in this study, the importance of PC on human AD should be demonstrated in future studies.
Although it is assumed that cold exposure triggers inflammation in patients with familial Mediterranean fever (FMF), seasonal differences in FMF have not yet been investigated. This study aims to investigate the association of seasonal changes with the frequency of attacks, disease severity, and subclinical inflammation in FMF. This longitudinal study examined adult patients with FMF on an established treatment followed up for at least 1 year in Istanbul. Clinical characteristics, medications, intraseasonal attacks counts, arthralgia and arthritis, disease severity, and the subclinical inflammation parameters were recorded covering four seasons. Friedman’s and Cochran’s Q tests were used to analyze changes in the above-mentioned data over seasons. Additionally, all attacks experienced in each season were added, and interseasonal differences were compared with the Chi-square goodness-of-fit test. Data for 240 observations (60 patients) were analyzed. The mean age and disease duration were 39.78 (SD 11.91) and 10 (IQR 6–22.75) years, respectively. The comparison of medians for four seasons did not show any statistical differences in terms of attack frequency, disease severity parameters, markers of subclinical inflammation, and the presence of arthralgia and arthritis. The total number of intraseasonal attacks experienced by patients differed among the seasons (p = 0.023), with a higher count in winter. Adult individuals with established FMF are more likely to experience attacks in winter than summer, but this difference may not be seen in the general parameters of disease activity/severity. This result supports the notion that there is a pronounced residual activity in winter.
Gadolinium Gallium Garnet nanophosphors with Yb³⁺/Er³⁺/Tm³⁺ triply-doped ions were synthesized via the Solgel Pechini method and annealed at different temperatures ranging from 800 to 1200 °C. The approximate average crystallite sizes were determined within the range of 26–56 nm by using X-ray diffraction analysis. Color-tunable up-conversion emission was explored in nanomaterials by varying excitation power under 975 nm excitation wavelength by varying excitation power and Tm³⁺ concentration for white light emission. Bright white light up-conversion luminescence from Yb³⁺/Er³⁺/Tm³⁺ tridoped Gd3Ga5O12 was recorded. The color quality coordinates for Gd3Ga5O12:2%Yb³⁺/1%Er³⁺/1.5%Tm³⁺ nanophosphors annealed at 1000 °C were found to be x = 0.3244, y = 0.3297 at room temperature under 975 nm infrared excitation, which falls within the white zone of the 1931 International Commission on Illumination diagram. Nanophosphors show extreme near-infrared radiation at 800 nm, which is also beneficial to deeper tissue penetration and promotes plants' growth.
A new exopolysaccharide (EPS) producing Gram-positive bacterium was isolated from the rhizosphere of Bouteloua dactyloides (buffalo grass) and its EPS product was structurally characterized. The isolate, designated as LB1-1A, was identified as Bacillus paralicheniformis based on 16S rRNA gene sequence and phylogenetic tree analysis. The EPS produced by LB1-1A was identified as a levan, having β(2 → 6) linked backbone with β(2 → 1) linkages at the branch points (4.66%). The isolate LB1-1A yielded large amount (~ 42 g/l) of levan having high weight average molecular weight (Mw) of 5.517 × 107 Da. The relatively low degree of branching and high molecular weight of this levan makes B. paralicheniformis LB1-1A a promising candidate for industrial applications.
Background Glycogen storage diseases type IIIa and b (GSDIII) are rare inherited metabolic disorders that are caused by deficiencies of the glycogen debranching enzyme, resulting in the accumulation of abnormal glycogen (‘limit dextrin’) in the muscles. The cardiac storage of limit dextrin causes a form of cardiomyopathy similar to primary hypertrophic cardiomyopathy. Treatment with a high fat diet is controversial but we report a positive outcome in a child with cardiomyopathy. Case presentation A 9-year-old boy with GSDIIIa developed left ventricular hypertrophy at 4.3 years of age. A high-fat (50%), high protein (20%), low-carbohydrates (30%) diet was introduced. After 18 months, echocardiogram, biochemical and clinical parameters improved (Creatine Kinase (CK), 1628➔1125 U/L; left ventricular outflow tract (LVOT), 35➔20 mmHg; interventricular septum (IVS), 21➔10 mm). The diet was abandoned for 2 years resulting in reversal of symptoms, but recommencement showed improvement after 6 months. Conclusion A high fat, high protein and low carbohydrate diet was successful in reversing cardiomyopathy. This form of treatment should be considered in children with GSD IIIa with cardiomyopathy.
Introduction Deep learning methods have recently been applied for the processing of medical images, and they have shown promise in a variety of applications. This study aimed to develop a deep learning approach for identifying oral lichen planus lesions using photographic images. Material and Methods Anonymous retrospective photographic images of buccal mucosa with 65 healthy and 72 oral lichen planus lesions were identified using the CranioCatch program (CranioCatch, Eskişehir, Turkey). All images were re-checked and verified by Oral Medicine and Maxillofacial Radiology experts. This data set was divided into training (n =51; n=58), verification (n =7; n=7), and test (n =7; n=7) sets for healthy mucosa and mucosa with the oral lichen planus lesion, respectively. In the study, an artificial intelligence model was developed using Google Inception V3 architecture implemented with Tensorflow, which is a deep learning approach. Results AI deep learning model provided the classification of all test images for both healthy and diseased mucosa with a 100% success rate. Conclusion In the healthcare business, AI offers a wide range of uses and applications. The increased effort increased complexity of the job, and probable doctor fatigue may jeopardize diagnostic abilities and results. Artificial intelligence (AI) components in imaging equipment would lessen this effort and increase efficiency. They can also detect oral lesions and have access to more data than their human counterparts. Our preliminary findings show that deep learning has the potential to handle this significant challenge.
OBJECTIVES To develop and validate an Arabic version of the pediatric lower urinary tract symptom score (PLUTSS). METHODS The linguistic translation of the PLUTSS into Arabic was carried out by following the guidelines that have been set out for cross-cultural adaptation of health-related QoL measures (Translation, Reconciliation, Retranslation, Review of retranslation, Debriefing and final review). The questionnaires were applied to 80 patients, 40 patients seeking urology clinic for lower urinary tract symptoms (LUTS) and 40 patients visiting a pediatric clinic without urological compliant. The discrimination validity and strength of association were tested using Mann-Whitney and chi-square tests. Reliability of translation was tested for internal consistency using the Cronbach’s α and ROC Curve was used to evaluate the ability of the questionnaire to discriminate between cases and controls. RESULTS Patients with LUTS had a higher PLUTSS score and QoL score than controls (P < 0.001). The value of Cronbach’s alpha of the 13 items (excluding Qol) evaluated on the scale was 0.717 (95% CI: 0.616–0.800). The ROC curve determined the ability of the questionnaire to discriminate between cases and controls where the area under the curve was 0.901 (95% CI: 0.830–0.972). CONCLUSION The Arabic translated version of the PLUTSS is an acceptable and reliable tool for assessing and evaluating pediatric patients with LUTS in Arabic-speaking countries.
Prior research has had a limited approach to identifying organisational factors related to knowledge management (KM) practices of higher education institutions (HEIs), the centre for knowledge creation. This qualitative study explored such factors affecting KM capabilities from the perspectives of 30 full-time academics in public universities, and identified the dimensions of the KM capabilities framework. Results revealed that physical conditions, budget, human and technological resource management, division of labour, workload, time management, communication, bureaucracy, structural differentiation, motivation, individualism, and organisational behaviour affect KM infrastructure capabilities; bureaucracy, KM teams, institutional platforms, organisational structure, knowledge maps, vision, individual attitudes, academic collaboration, process management, budget, decision-making processes, sustainable academic KM, transparency, labour force, knowledge security, organisational culture, accessibility, and archiving affect KM process capabilities. These results contribute to identifying the organisational factors influencing KM that are critical to guiding practitioners and administrators of HEIs in developing more effective KM strategies and practices.
Aim: Chirality of drugs might be associated with safety issues through pharmacokinetic or pharmacodynamic variations, interactions, or direct toxicological responses. We aimed to compare chiral status of the available drugs to that of drugs withdrawn due to adverse drug reactions (ADRs). Methods: We searched the literature regarding withdrawn drugs due to safety-related issues (n=391) to compare them with all available small-molecule drugs (n=1633). We examined their chiral status and assigned as achiral compound, chiral mixture, or pure enantiomer. We compared the mean survival (i.e., non-withdrawal) time and withdrawal rates of drugs by their chirality, with further stratification by the launch year, ATC-1 (Anatomical Therapeutic Chemical) level, and ADR. Results: We identified higher withdrawal rate in achiral drugs (HR 2.1, 95% CI: 1.6-2.7) and chiral mixtures (HR 2.6, 95% CI: 1.9-3.5) compared to that in pure enantiomers. Pure enantiomers had the longest mean survival time (62.4±0.8 years), followed by achiral drugs (55.4±0.9 years, p<0.01) and chiral mixtures (52.4±1.4 years, p<0.01). Pure enantiomers had higher survival rates than chiral mixtures if launched before 1941 (p=0.02), in 1961-1980 (p<0.001), or 1981-2000 (p<0.001). Pure enantiomers had lower withdrawal rate (18.2%) vs. chiral mixtures (35.1%, p=0.02) in nervous system drugs. Pure enantiomers had lower withdrawal rate than chiral mixtures in hepatotoxic (p<0.01) and cardiovascular ADRs (p<0.01). Conclusion: Our study showed lower likelihood of withdrawal for pure enantiomers compared to that in chiral mixtures and achiral drugs, which was more remarkable for those launched in certain time periods and several ADRs, including hepatotoxicity and cardiovascular toxicity.
Objectives Behçet’s Disease (BD) is a unique systemic vasculitis mainly involving veins in contrast to other vasculitides. Prior studies showed that pulmonary arteries (PA) have a similar structure to systemic veins. In this study, we aimed to assess PA wall thickness by transthoracic echocardiography (TTE) in BD patients compared with healthy controls (HC) and patients with non-inflammatory pulmonary embolism (NIPE). Methods Patients with BD (n = 77), NIPE (n = 33) and HC (n = 57) were studied. PA wall thickness was measured from the mid-portion of the main PA with TTE by two cardiologists blinded to cases. Results PA wall thickness was significantly lower in HC (3.6 (0.3) mm) compared with NIPE (4.4 (0.5) mm) and BD (4.4 (0.6) mm) (p< 0.001 for both). PA wall thickness was similar between BD and NIPE (p= 0.6). Among patients with BD, PA wall thickness was significantly higher in patients with major organ involvement compared with mucocutaneous limited disease (4.7 (0.4) mm vs 3.7 (0.4) mm, p< 0.001), HC and NIPE (p< 0.001 and p= 0.006, respectively). PA wall thickness was comparable between patients with vascular and non-vascular major organ involvement (4.6 (0.5) mm vs 4.7 (0.3) mm, p= 0.3). Conclusion We observed that PA wall thickness was significantly higher in BD with major organ involvement compared with patients with only mucocutaneous limited disease, HC and NIPE. These results suggest that increased PA wall thickness may be a sign of severe disease with major organ involvement in BD.
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10,358 members
Orkun Pinar
  • Department of Bio-Engineering
Huseyin Bilgin
  • Department of Infectious Diseases
Mehmet Eroglu
  • Department of Chemical Engineering
Sule Cetinel
  • Department of Histology and Embryology
Bahattin Yalcin
  • Department of Chemistry
Buyuk Ciftlik Sokak No:6 Nisantasi, 34365, Istanbul, Turkey