Ankara Yıldırım Beyazıt University

On January 30, 2020, the WHO declared the COVID-19 outbreak a public health emergency of international concern and, in March 2020, began to characterize it as a pandemic in order to emphasize the gravity of the situation and urge all countries to take action in detecting infection and preventing spread. Unfortunately, there is no medication that has been approved by the FDA, gone through controlled studies and demonstrated an effect on the virus for this global pandemic. Although there are cures for illnesses and developments made by leaps and bounds in our day, the strongest and most effective weapon that society has against this virus that is affecting not just health but also economics, politics, and social order, is the prevention of its spread. The main points in preventing the spread in society are hand hygiene, social distancing and quarantine. With increased testing capacity, detecting more COVID-19 positive patients in the community will also enable the reduction of secondary cases with stricter quarantine rules.

There is concern about an emerging diabetes epidemic in Turkey. We aimed to determine the prevalence of diagnosed and undiagnosed diabetes, prediabetes and their 12-year trends and to identify risk factors for diabetes in the adult Turkish population. A cross-sectional, population-based survey, 'TURDEP-II' included 26,499 randomly sampled adults aged ≥ 20 years (response rate: 87 %). Fasting glucose and biochemical parameters were measured in all; then a OGTT was performed to identify diabetes and prediabetes in eligible participants. The prevalence of diabetes was 16.5 % (new 7.5 %), translating to 6.5 million adults with diabetes in Turkey. It was higher in women than men (p = 0.008). The age-standardized prevalence to the TURDEP-I population (performed in 1997-98) was 13.7 % (if same diagnostic definition was applied diabetes prevalence is calculated 11.4 %). The prevalence of isolated-IFG and impaired glucose tolerance (IGT), and combined prediabetes was 14.7, 7.9, and 8.2 %, respectively; and that of obesity 36 % and hypertension 31.4 %. Compared to TURDEP-I; the rate of increase for diabetes: 90 %, IGT: 106 %, obesity: 40 % and central obesity: 35 %, but hypertension decreased by 11 % during the last 12 years. In women age, waist, body mass index (BMI), hypertension, low education, and living environment; in men age, BMI, and hypertension were independently associated with an increased prevalence of diabetes. In women current smoking, and in men being single were associated with a reduced risk. These results from one of the largest nationally representative surveys carried out so far show that diabetes has rapidly become a major public health challenge in Turkey. The figures are alarming and underscore the urgent need for national programs to prevent diabetes, to manage the illness and thus prevent complications.

Fen, sosyal ve sağlık bilimlerinde yapılan ölçek uyarlama ve geliştirme çalışmalarının yapısal geçerliliğinin test edilmesi önemlidir. Geçerliliğin test edilmesi, doğrudan ölçülebilen gözlenen ve doğrudan ölçülemeyen gizil değişkenler olmak üzere, temelde iki değişken üzerine kurulan yapının veri tarafından sınanması mantığına dayanmaktadır. Bu çalışmada, Yapısal Eşitlik Modelleri (YEM) grubundan olan Doğrulayıcı Faktör Analizi (DFA) incelenmiştir. Teorik yapıya sahip olan DFA, Yapısal Eşitlik Modellerinin (YEM) bir türüdür ve uygulaması zor olan bir analiz yöntemidir. Ayrıca modelin veri tarafından sınanmasında, modelin uyumunu ortaya koyan uyum indekslerine yer verilmiştir. Çocuklarda Yeme Davranışı Anketi (ÇYDA) verileri kullanılıp, LISREL programının önerdiği farklı modeller sınanarak, model iyileştirmesi yapılmıştır. DFA ve uyum indeksleri uygulaması için Yılmaz ve ark. tarafından Mayıs-Haziran 2008 tarihleri arasında Gaziosmanpaşa Üniversitesi Tıp Fakültesi Pediatri Anabilim Dalı polikliniğine başvuran çocukların ve Tokat ilindeki anaokulu ve anasınıflarına devam eden öğrencilerin ebeveynlerine (n=468) uygulanmış olan Çocuklarda Yeme Davranışı Anketi (ÇYDA) verileri kullanılmıştır. Açıklayıcı Faktör Analizi (AFA) değerleri iyi düzeyde seyreden bir çalışmanın DFA sonuçlarının, AFA'da bulunandan daha kötü olduğu görülmektedir. Uygulamada Lisrel programının önerdiği düzeltmelerle üretilen 5 modelin sonuçlarına göre, modelin ürettiği uyum indekslerinde düzelme olduğu gösterilmiştir. Yapısal geçerliliğin sınanmasında, açıklayıcılığı göz önünde bulunduran AFA'ya ait bulguların, DFA ile sınanıp gerektiğinde model düzeltmesine gidilmesi, modeli daha kullanışlı ve geçerli kılacaktır.

Chemoresistance is a major obstacle in triple negative breast cancer (TNBC), the most aggressive breast cancer subtype. Here we identify hypoxia-induced ECM re-modeler, lysyl oxidase (LOX) as a key inducer of chemoresistance by developing chemoresistant TNBC tumors in vivo and characterizing their transcriptomes by RNA-sequencing. Inhibiting LOX reduces collagen cross-linking and fibronectin assembly, increases drug penetration, and downregulates ITGA5/FN1 expression, resulting in inhibition of FAK/Src signaling, induction of apoptosis and re-sensitization to chemotherapy. Similarly, inhibiting FAK/Src results in chemosensitization. These effects are observed in 3D-cultured cell lines, tumor organoids, chemoresistant xenografts, syngeneic tumors and PDX models. Re-expressing the hypoxia-repressed miR-142-3p, which targets HIF1A, LOX and ITGA5, causes further suppression of the HIF-1α/LOX/ITGA5/FN1 axis. Notably, higher LOX, ITGA5, or FN1, or lower miR-142-3p levels are associated with shorter survival in chemotherapy-treated TNBC patients. These results provide strong pre-clinical rationale for developing and testing LOX inhibitors to overcome chemoresistance in TNBC patients.

Abstract Perovskite solar cells (PSCs) have become a promising photovoltaic (PV) technology, where the evolution of the electron‐selective layers (ESLs), an integral part of any PV device, has played a distinctive role to their progress. To date, the mesoporous titanium dioxide (TiO 2 )/compact TiO 2 stack has been among the most used ESLs in state‐of‐the‐art PSCs. However, this material requires high‐temperature sintering and may induce hysteresis under operational conditions, raising concerns about its use toward commercialization. Recently, tin oxide (SnO 2 ) has emerged as an attractive alternative ESL, thanks to its wide bandgap, high optical transmission, high carrier mobility, suitable band alignment with perovskites, and decent chemical stability. Additionally, its low‐temperature processability enables compatibility with temperature‐sensitive substrates, and thus flexible devices and tandem solar cells. Here, the notable developments of SnO 2 as a perovskite‐relevant ESL are reviewed with emphasis placed on the various fabrication methods and interfacial passivation routes toward champion solar cells with high stability. Further, a techno‐economic analysis of SnO 2 materials for large‐scale deployment, together with a processing‐toxicology assessment, is presented. Finally, a perspective on how SnO 2 materials can be instrumental in successful large‐scale module and perovskite‐based tandem solar cell manufacturing is provided.

BACKGROUND: The primary aim of this randomized study was to describe the feasibility of early administration of surfactant via a thin catheter during spontaneous breathing (Take Care) and compare early mechanical ventilation (MV) requirement with the InSurE (Intubate, Surfactant, Extubate) procedure. METHODS: Preterm infants, who were <32 weeks and stabilized with nasal continuous positive airway pressure (nCPAP) in the delivery room, were randomized to receive early surfactant treatment either by the Take Care or InSurE technique. Tracheal instillation of 100 mg/kg poractant α via 5-F catheter during spontaneous breathing under nCPAP was performed in the intervention group. In the InSurE procedure, infants were intubated, received positive pressure ventilation for 30 seconds after surfactant instillation, and placed on nCPAP immediately. RESULTS: One hundred infants in each group were analyzed. The MV requirement in the first 72 hours of life was significantly lower in the Take Care group when compared with the InSurE group (30% vs 45%, P = .02, odds ratio -0.52, 95% confidence interval -0.94 to -0.29). Mean duration of both nCPAP and MV were significantly shorter in the Take Care group (P values .006 and .002, respectively). Bronchopulmonary dysplasia rate was significantly lower among the infants treated with the Take Care technique (relative risk -0.27, 95% confidence interval -0.1 to -0.72) CONCLUSIONS: The Take Care technique is feasible for the treatment of respiratory distress syndrome in infants with very low birth weight. It significantly reduces both the need and duration of MV, and thus the bronchopulmonary dysplasia rate in preterm infants.

In the field of medicine, with the introduction of computer systems that can collect and analyze massive amounts of data, many non-invasive diagnostic methods are being developed for a variety of conditions. In this study, our aim is to develop a non-invasive method of classifying respiratory sounds that are recorded by an electronic stethoscope and the audio recording software that uses various machine learning algorithms. In order to store respiratory sounds on a computer, we developed a cost-effective and easy-to-use electronic stethoscope that can be used with any device. Using this device, we recorded 17,930 lung sounds from 1630 subjects. We employed two types of machine learning algorithms; mel frequency cepstral coefficient (MFCC) features in a support vector machine (SVM) and spectrogram images in the convolutional neural network (CNN). Since using MFCC features with a SVM algorithm is a generally accepted classification method for audio, we utilized its results to benchmark the CNN algorithm. We prepared four data sets for each CNN and SVM algorithm to classify respiratory audio: (1) healthy versus pathological classification; (2) rale, rhonchus, and normal sound classification; (3) singular respiratory sound type classification; and (4) audio type classification with all sound types. Accuracy results of the experiments were; (1) CNN 86%, SVM 86%, (2) CNN 76%, SVM 75%, (3) CNN 80%, SVM 80%, and (4) CNN 62%, SVM 62%, respectively. As a result, we found out that spectrogram image classification with CNN algorithm works as well as the SVM algorithm, and given the large amount of data, CNN and SVM machine learning algorithms can accurately classify and pre-diagnose respiratory audio.

PURPOSE Pembrolizumab monotherapy is standard first-line therapy for metastatic non–small-cell lung cancer (NSCLC) with programmed death ligand 1 (PD-L1) tumor proportion score (TPS) ≥ 50% without actionable driver mutations. It is not known whether adding ipilimumab to pembrolizumab improves efficacy over pembrolizumab alone in this population. METHODS In the randomized, double-blind, phase III KEYNOTE-598 trial (ClinicalTrials.gov identifier: NCT03302234 ), eligible patients with previously untreated metastatic NSCLC with PD-L1 TPS ≥ 50% and no sensitizing EGFR or ALK aberrations were randomly allocated 1:1 to ipilimumab 1 mg/kg or placebo every 6 weeks for up to 18 doses; all participants received pembrolizumab 200 mg every 3 weeks for up to 35 doses. Primary end points were overall survival and progression-free survival. RESULTS Of the 568 participants, 284 were randomly allocated to each group. Median overall survival was 21.4 months for pembrolizumab-ipilimumab versus 21.9 months for pembrolizumab-placebo (hazard ratio, 1.08; 95% CI, 0.85 to 1.37; P = .74). Median progression-free survival was 8.2 months for pembrolizumab-ipilimumab versus 8.4 months for pembrolizumab-placebo (hazard ratio, 1.06; 95% CI, 0.86 to 1.30; P = .72). Grade 3-5 adverse events occurred in 62.4% of pembrolizumab-ipilimumab recipients versus 50.2% of pembrolizumab-placebo recipients and led to death in 13.1% versus 7.5%. The external data and safety monitoring committee recommended that the study be stopped for futility and that participants discontinue ipilimumab and placebo. CONCLUSION Adding ipilimumab to pembrolizumab does not improve efficacy and is associated with greater toxicity than pembrolizumab monotherapy as first-line treatment for metastatic NSCLC with PD-L1 TPS ≥ 50% and no targetable EGFR or ALK aberrations. These data do not support use of pembrolizumab-ipilimumab in place of pembrolizumab monotherapy in this population.

Using blockchain technology as one of the new methods to enhance the cyber and physical security of power systems has grown in importance over the past few years. Blockchain can also be used to improve social welfare and provide sustainable energy for consumers. In this article, the effect of distributed generation (DG) resources on the transmission power lines and consequently fixing its conjunction and reaching the optimal goals and policies of this issue to exploit these resources is investigated. In order to evaluate the system security level, a false data injection attack (FDIA) is launched on the information exchanged between independent system operation (ISO) and under-operating agents. The results are analyzed based on the cyber-attack, wherein the loss of network stability as well as economic losses to the operator would be the outcomes. It is demonstrated that cyber-attacks can cause the operation of distributed production resources to not be carried out correctly and the network conjunction will fall to a large extent; with the elimination of social welfare, the main goals and policies of an independent system operator as an upstream entity are not fulfilled. Besides, the contracts between independent system operators with distributed production resources are not properly closed. In order to stop malicious attacks, a secured policy architecture based on blockchain is developed to keep the security of the data exchanged between ISO and under-operating agents. The obtained results of the simulation confirm the effectiveness of using blockchain to enhance the social welfare for power system users. Besides, it is demonstrated that ISO can modify its polices and use the potential and benefits of distributed generation units to increase social welfare and reduce line density by concluding contracts in accordance with the production values given.

Ki67 index is now an essential part of classification of pancreatic neuroendocrine tumors. However, its adaptation into daily practice has been fraught with challenges related to counting methodology. In this study, three reviewers used four counting methodologies to calculate Ki67 index in 68 well-differentiated pancreatic neuroendocrine tumors: (1) 'eye-ball' estimation, which has been advocated as reliable and is widely used; (2) automated counting by image analyzer; (3) manual eye-counting (eye under a microscope without a grid); and (4) manual count of camera-captured/printed image. Pearson's correlation (R) was used to measure pair-wise correlation among three reviewers using all four methodologies. Average level of agreement was calculated using mean of R values. The results showed that: (1) 'eye-balling' was least expensive and fastest (average time <1 min) but had poor reliability and reproducibility. (2) Automated count was the most expensive and least practical with major impact on turnaround time (limited by machine and personnel accessibility), and, more importantly, had inaccuracies in overcounting unwanted material. (3) Manual eye count had no additional cost, averaged 6 min, but proved impractical and poorly reproducible. (4) Camera-captured/printed image was most reliable, had highest reproducibility, but took longer than 'eye-balling'. In conclusion, based on its comparatively low cost/benefit ratio and reproducibility, camera-captured/printed image appears to be the most practical for calculating Ki67 index. Although automated counting is generally advertised as the gold standard for index calculation, in this study it was not as accurate or cost-effective as camera-captured/printed image and was highly operator-dependent. 'Eye-balling' produces highly inaccurate and unreliable results, and is not recommended for routine use.

The main objective of this study is to investigate the intellectual structure and evolution of author collaborations from articles published in the Strategic Management Journal between 1980 and 2014. This assessment includes the general view of authorship, authorship patterns, author productivity, ranking of authors, visualization of the co-authorship network, comparison of strategic management co-authorship network attributes with those of other disciplines, the evolution of main components and core authors in the networks by period, discussions on whether the strategic management network fits with the small world network theory, individual network attributes such as degree centrality, Bonacich's power index, closeness centrality, and betweenness centrality. Finally, the authors provide an inclusive evaluation of the results, limitations, and suggestions for future research.

OBJECTIVE: The frequency of vaccine refusal, which is associated with many factors, is increasing worldwide. The aim of this study was to predict the frequency of vaccine refusal against domestic and foreign COVID-19 vaccines and identify the factors underlying refusal. METHODS: A survey consisting of 16 questions about COVID-19 vaccination was conducted either face-to-face or online with 428 parents who agreed to participate in the study. The parents had children who were inpatients or outpatients in the Children's Hospital of Ankara City Hospital. In the survey, parents were asked about family sociodemographic characteristics, opinions on domestic and foreign COVID-19 vaccines, and reasons for vaccine refusal. RESULTS: While 66.1% of parents were reluctant to receive foreign COVID-19 vaccines, only 37.4% were reluctant to receive domestic COVID-19 vaccines. The participants' preference for the domestic vaccine was significantly higher for themselves and their children (P < 0.05). Women were less likely to be willing to receive foreign vaccines than men (P < 0.05). As the education level increased, fewer parents preferred the domestic vaccine for themselves (P = 0.046) and their children (P = 0.005). Both domestic and foreign vaccine acceptability for parents and their children was higher among parents with high anxiety levels regarding COVID-19 infection (P < 0.05). The most common reasons for refusal were anxiety about vaccine side effects, lack of knowledge about the effectiveness of vaccines, and distrust of vaccines originating from abroad. CONCLUSION: Most of the participants were hesitant about COVID-19 vaccines. This study demonstrates that vaccine uptake can be increased by considering the higher preference for domestic vaccines.

PURPOSE: This study aimed to provide an update and compare perioperative outcomes and complications of intracorporeal and extracorporeal urinary diversion following robot-assisted radical cystectomy using data from the multi-institutional, prospectively maintained International Robotic Cystectomy Consortium database. MATERIALS AND METHODS: We retrospectively reviewed the records of 2,125 patients from a total of 26 institutions. Intracorporeal urinary diversion was compared with extracorporeal urinary diversion. Multivariate logistic regression models using stepwise variable selection were fit to evaluate preoperative, operative and postoperative predictors of intracorporeal urinary diversion, operative time, high grade complications and 90-day hospital readmissions after robot-assisted radical cystectomy. RESULTS: In our cohort 1,094 patients (51%) underwent intracorporeal urinary diversion. These patients demonstrated shorter operative time (357 vs 400 minutes), less blood loss (300 vs 350 ml) and fewer blood transfusions (4% vs 19%, all p <0.001). They experienced more high grade complications (13% vs 10%, p = 0.02). Intracorporeal urinary diversion use increased from 9% of all urinary diversions in 2005 to 97% in 2015. Complications after this procedure decreased significantly with time (p <0.001). On multivariable analysis higher annual cystectomy volume (OR 1.02, 95% CI 1.01-1.03, p <0.002), year of robot-assisted radical cystectomy (2013-2016 OR 68, 95% CI 44-105, p <0.001) and American Society of Anesthesiologists® score less than 3 (OR 1.75, 95% CI 1.38-2.22, p <0.001) were associated with undergoing intracorporeal urinary diversion. The procedure was associated with a shorter operative time of 27 minutes (p = 0.001). CONCLUSIONS: The use of intracorporeal urinary diversion has increased in the last decade. A higher annual institutional volume of robot-assisted radical cystectomy was associated with intracorporeal urinary diversion as well as with shorter operative time. Although intracorporeal urinary diversion was associated with higher grade complications than extracorporeal urinary diversion, they decreased with time.

The study reported herein proposes a new method for the diagnosis of epilepsy from electroencephalography (EEG) signals based on complex classifiers. To carry out this study, first the features of EEG data are extracted using a dual-tree complex wavelet transformation at different levels of granularity to obtain size reduction. In subsequent phases, five features (based on statistical measurements maximum value, minimum value, arithmetic mean, standard deviation, median value) are obtained by using the feature vectors, and are presented as the input dimension to the complex-valued neural networks. The evaluation of the proposed method is conducted using the k-fold cross-validation methodology, reporting on classification accuracy, sensitivity, and specificity. The proposed method is tested using a benchmark EEG dataset, and high accuracy rates were obtained. The stated results show that the proposed method can be used to design an accurate classification system for epilepsy diagnosis.

BACKGROUND: To evaluate the prevalence, risk factors and treatment of retinopathy of prematurity (ROP) in Turkey and to establish screening criteria for this condition. METHODS: A prospective cohort study (TR-ROP) was performed between 1 April 2016 and 30 April 2017 in 69 neonatal intensive care units (NICUs). Infants with a birth weight (BW)≤1500 g or gestational age (GA)≤32 weeks and those with a BW>1500 g or GA>32 weeks with an unstable clinical course were included in the study. Predictors for the development of ROP were determined by logistic regression analyses. RESULTS: The TR-ROP study included 6115 infants: 4964 (81%) with a GA≤32 weeks and 1151 (19%) with a GA>32 weeks. Overall, 27% had any stage of ROP and 6.7% had severe ROP. A lower BW, smaller GA, total days on oxygen, late-onset sepsis, frequency of red blood cell transfusions and relative weight gain were identified as independent risk factors for severe ROP in infants with a BW≤1500 g. Of all infants, 414 needed treatment and 395 (95.4%) of the treated infants had a BW≤1500 g. Sixty-six (16%) of the treated infants did not fulfil the Early Treatment for Retinopathy of Prematurity requirements for treatment. CONCLUSIONS: Screening of infants with a GA≤34 weeks or a BW<1700 g appears to be appropriate in Turkey. Monitoring standards of neonatal care and conducting quality improvement projects across the country are recommended to improve neonatal outcomes in Turkish NICUs. TRIAL REGISTRATION NUMBER: NCT02814929, Results.

In the paper titled “Does Urinary Bladder Shape Affect Urinary Flow Rate in Men with Lower Urinary Tract Symptoms?” we should add an author who has contributed to our study for the images: Murat Cinar, Department of Biomedical Engineering, Faculty of Engineering and Architecture, Izmir Katip Celebi University, 35620 Izmir, Turkey. In addition we should here correct the affiliation of one of the authors named Omer Karal and the postal code in the affiliation of the author Mahmut Pekedis.

In this paper, we reviewed the purification and characterization methods of the α-carbonic anhydrase (CA, EC 4.2.1.1) class. Six genetic families (α-, β-, γ-, δ-, ζ- and η-CAs) all know to date, all encoding such enzymes in organisms widely distributed over the phylogenetic tree. Starting from the manuscripts published in the 1930s on the isolation and purification of α-CAs from blood and other tissues, and ending with the recent discovery of the last genetic family in protozoa, the η-CAs, considered for long time an α-CA, we present historically the numerous and different procedures which were employed for obtaining these catalysts in pure form. α-CAs possess important application in medicine (as many human α-CA isoforms are drug targets) as well as biotechnological processes, in which the enzymes are ultimately used for CO2 capture in order to mitigate the global warming effects due to greenhouse gases. Recently, it was discovered an involvement of CAs in cancerogenesis as well as infection caused by pathogenic agents such as bacteria, fungi and protozoa. Inhibition studies of CAs identified in the genome of the aforementioned organisms might lead to the discovery of innovative drugs with a novel mechanism of action.

Abstract This study investigated how small and medium enterprises (SMEs) in a country perceive major global risks. The aim was to explore how country attributes and circumstances affect SME assessments of the likelihood, impacts, and rankings of global risks, and to find out if SME risk assessment and rankings differ from the global rankings. Data were gathered using an online survey of manufacturing SMEs in Turkey. The results show that global economic risks and geopolitical risks are of major concern for SMEs, and environmental risks are at the bottom of their ranking. Among the economic risks, fiscal crises in key economies and high structural unemployment or underemployment were found to be the highest risks for the SMEs. Failure of regional or global governance, failure of national governance, and interstate conflict with regional consequences were found to be among the top geopolitical risks for the SMEs. The SMEs considered the risk of large-scale cyber-attacks and massive incident of data fraud/theft to be relatively higher than other global technological risks. Profound social instability and failure of urban planning were among the top societal risks for the SMEs. Although the global environmental and disaster risks were ranked lowest on the list, man-made environmental damage and disasters and major natural hazard-induced disasters were ranked the highest among this group of risks. Overall, the results show that SMEs at a country level, for example Turkey, perceive global risks differently than the major global players.

Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of OAS1 , OAS2 , or RNASEL in five unrelated children with MIS-C. The cytosolic double-stranded RNA (dsRNA)–sensing OAS1 and OAS2 generate 2′-5′-linked oligoadenylates (2-5A) that activate the single-stranded RNA–degrading ribonuclease L (RNase L). Monocytic cell lines and primary myeloid cells with OAS1, OAS2, or RNase L deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stimulation. Exogenous 2-5A suppresses cytokine production in OAS1-deficient but not RNase L–deficient cells. Cytokine production in RNase L–deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by mitochondrial antiviral-signaling protein (MAVS) deficiency. Recessive OAS–RNase L deficiencies in these patients unleash the production of SARS-CoV-2–triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C.

Post recovery manifestations have become another concern in patients who have recovered from coronavirus disease 2019 (COVID-19). Numerous reports have shown that COVID-19 has a variety of long-term effects on almost all systems including respiratory, cardiovascular, gastrointestinal, neurological, psychiatric, and dermatological systems. We aimed to investigate the prevalence and characteristics of the post-COVID syndrome among COVID-19 survivors and to determine the factors associated with persistent symptoms. This prospective study enrolled in patients with COVID-19 followed in hospital or outpatient clinics in Ankara City Hospital. We performed a special questionnaire to inquire about the presence of persistent symptoms beyond 12 weeks from the first diagnosis. Demographic data, comorbid diseases, characteristics of acute COVID-19, presence of persistent symptoms by systems, and knowledge about outpatient clinic visits after recovery were assessed. Of a total of 1007 participants, 39.0% had at least one comorbidity, and 47.5% had persistent symptoms. Fatigue/easy fatigability, myalgia, and loss of weight were the most frequent persistent symptoms (overall 29.3%) followed by respiratory symptoms (25.4%). A total of 235 participants had visited outpatient clinics due to several reasons during the post-COVID-19 period, and 17 of them were hospitalized. Severe acute COVID-19, hospitalization, and presence of comorbidity were independent factors for the development of persistent symptoms. Fully understanding the spectrum of the post-COVID syndrome is essential for appropriate management of all its long-term effects. Our study once again underlined the fact that the prevalence of post-COVID syndrome is higher than expected and concerns many systems, and a multidisciplinary follow-up should be provided to COVID-19 survivors in the post recovery period.