Mustafa Koçak - Academia.edu (original) (raw)

Papers by Mustafa Koçak

Turkish Journal of Fisheries and Aquatic Sciences, 2015

Aerosol filter samples were selected from sample library of Erdemli site; located on the coastlin... more Aerosol filter samples were selected from sample library of Erdemli site; located on the coastline of the Eastern Mediterranean, in order to carry out solubility experiments. The nutrient (PO4 3- , Sidiss, NO3 - and NH4 + ) solubilities were investigated by using pure-water and sea-water. The arithmetic means of phosphate and dissolved silica indicated distinct difference (larger than 50 %) between pure-water and sea-water whereas; the calculated mean concentrations of nitrate and ammonium did not reveal substantial discrepancy for pure-water and sea-water extractions. The difference for phosphate and silicate might be attributed to pH and ionic strength of sea water, size distribution and association of phosphate/silicate particles with less soluble compounds such as calcium phosphate, kaolinite, opal, quartz and origin of the aerosol species. The difference between pure-water and sea-water extractions for nitrate and ammonium was estimated to be small, corresponding to 1 % to -3 %...

Journal of Oral Health and Community Dentistry, 2020

Aim: This study aimed to assess the knowledge and anxiety levels of dentists and pregraduate dent... more Aim: This study aimed to assess the knowledge and anxiety levels of dentists and pregraduate dental students about COVID-19 in Turkey. Materials and Methods: A three-part online questionnaire was used to collect data. Questionnaire 1 consisted of 10 demographic questions. In questionnaire 2, there were 10 multiple-choice questions, including various COVID-19 knowledge. In questionnaire 3, participants were tested by a self-evaluation test as Worry and Anxiety Questionnaire (WAQ). Results: A total of 1002 respondents had completed the questionnaires. The majority of the participants exhibited very good knowledge. Worry and anxiety scores differ by gender, institution, and specialty (p < 0,001). There was no significant relationship between knowledge level and stress level (p > 0,050). Conclusion: Female dentists, pediatric dentists, and dentists working in public hospitals in Turkey were found to be significantly more stressed. The level of knowledge was generally high and no correlation was established by the level of anxiety. Clinical Significance: In this global pandemic process, it is known that all dentists' problems and needs are common, and the effects of the disease on the dental profession can be globalized. It is crucial in the face of the anxiety and stress demonstrated by dentists during COVID-19 that mental coping mechanisms and strategies generated to remain calm and function efficiently.

Educational Research and Reviews, Aug 10, 2015

The purpose of this study is to investigate the self-esteem levels of futsal players according to... more The purpose of this study is to investigate the self-esteem levels of futsal players according to certain variables. The samples of the study constituted 119 females and 96 males; a total of 215 players with an average age of 21.57± 2.20 years. The research was carried out with the end of "Rosenberg self-esteem Scale" developed by Rosenberg in 1965 and adapted to Turkish by Çuhadaroğlu. The data collected were analyzed by SPSS 19.0 statistical software and the inter group correlation coefficient was found to be .70. The non-parametric Kruskall-Wallis and Man-Whitney U test were also employed since the data obtained were unable to satisfy the non-parametric assumptions. The results of the data analysis revealed that the self-esteem levels of 93% of the participants were medium or high. The Mann-Whitney U test results showed that there was a statistically significant difference between the self-esteem levels of the male and female participants [Z(213)=-3.86; p<0.05]. The self-esteem levels of the participants according to age groups [ (215)= 12.92; p<0.05] and perceived income levels [ (215)= 13.47; p<0.05] were also observed to show statistically significant differences according to Kruskal-Wallis Variance analysis .In conclusion, the self-esteem levels of the female participants and the participants having medium perceived income levels were found to be higher than the others. However, the self-esteemlevels were observed to decrease with the increasing age.

Science of The Total Environment, 2019

• Comparison of online and offline measurements of sulfate, ammonium, nitrate in PM 2.5 • The tem... more • Comparison of online and offline measurements of sulfate, ammonium, nitrate in PM 2.5 • The temporal and diurnal variability of sulfate, ammonium, nitrate in PM 2.5 and their precursor gases • The impact of air flow on measurements of sulfate, ammonium, nitrate in PM 2.5

Journal of the Atmospheric Sciences, 2016

Two-sized aerosol samples were obtained from a rural site located close to Sinop on the south coa... more Two-sized aerosol samples were obtained from a rural site located close to Sinop on the south coastline of the Black Sea. In addition, bulk deposition samples were collected at Varna, located on the west coastline of the Black Sea. Both aerosol and deposition samples were analyzed for the main macronutrients, NO3−, NH4+, and PO43−. The mean aerosol nitrate and ammonium concentrations were 7.1 ± 5.5 and 22.8 ± 17.8 nmol m−3, respectively. The mean aerosol phosphate concentration was 0.69 ± 0.31 nmol m−3, ranging from 0.21 to 2.36 nmol m−3. Interestingly, phosphate concentration over Sinop was substantially higher than those of most Mediterranean sites. Comparison of the atmospheric and riverine inputs for the Black Sea revealed that atmospheric dissolved inorganic nitrogen (DIN) only ranged between 4% and 13%, while the atmospheric dissolved inorganic phosphorus (DIP) fluxes had significantly higher contributions with values ranging from 12% to 37%. The molar N:P ratios in atmospheri...

Biogeosciences Discussions, 2014

To obtain a comprehensive picture on the spatial distribution of water soluble organic nitrogen (... more To obtain a comprehensive picture on the spatial distribution of water soluble organic nitrogen (WSON) in marine aerosols, samples were collected during research cruises in the tropical and south Atlantic Ocean and during a one year period (2005) over the southern Indian Ocean (Amsterdam island). Samples have been analyzed for both organic and inorganic forms of nitrogen and the factors controlling their levels have been examined. Fine mode WSON was found to play a significant role in the remote marine atmosphere with enhanced biogenic activity, with concentrations of WSON (11.3 ± 3.3 nmol N m<sup>–3</sup>) accounting for about 84% of the total dissolved nitrogen (TDN). Such levels are similar to those observed in the polluted marine atmosphere of the eastern Mediterranean (11.6 ± 14.0 nmol N m<sup>–3</sup>). Anthropogenic activities were found to be an important source of atmospheric WSON as evidenced by the ten times higher levels in the Norther...

Archives of Rheumatology, 2014

Objectives: This study aims to investigate ultrasound examination findings of cartilage, tendon a... more Objectives: This study aims to investigate ultrasound examination findings of cartilage, tendon and nerve structures in patients with acromegaly and assess whether imaging findings have any association with the clinical and laboratory features of the patients. Patients and methods: The study included 38 diagnosed acromegaly patients (18 males, 20 females; mean age 45.6±10.4 years; range 28 to 63 years) and 21 control subjects (8 males, 13 females; mean age; 43.1±7.4 years; range 29 to 58 years) similar for age, sex and body mass index. Patients' clinical characteristics and laboratory parameters were recorded. The cross sectional area of median nerve, flexor pollicis longus and Achilles tendon, and humeral cartilage thickness were bilaterally assessed by ultrasound. Results: Arthralgia was present in 13 patients (34.9%) and 11 (28.9%) had paresthesia in the hands. Thickness of humeral cartilage and the cross sectional area of median nerve, flexor pollicis longus tendon and Achilles tendon was significantly higher in acromegaly patients compared with controls (p<0.001). While measurements performed with ultrasound were correlated among themselves, no significant correlation was present between ultrasound measurements and growth hormone and insulin-like growth factor-1. When acromegaly patients were analyzed as active (n=22) and inactive (n=16), no significant difference was determined in the parameters with the exception of median nerve measurements. Conclusion: Ultrasound examination revealed significantly different cartilage, tendon and nerve parameters in acromegaly patients compared to the control group. Median nerve cross sectional area was significantly greater in active patients compared to inactive patients.

Acta Endocrinologica-Bucharest, 2014

Background. HDR syndrome is an autosomal dominant disorder characterized by hypoparathyroidism, s... more Background. HDR syndrome is an autosomal dominant disorder characterized by hypoparathyroidism, sensorineural deafness, and renal dysplasia caused by mutation of the GATA3 gene. Case report. We describe a case of HDR syndrome diagnosed in a 46-yearold male patient. He had hand numbness, intermittent dizziness, and imbalance due to hypocalcemia. Physical examination was slim in appearance, had marfanoid features, and presented the typical apathetic face. He had a narrow rib cage and pectus excavatum deformity. Laboratory findings included serum calcium of 7.4 mg/dL, phosphorus of 4.87 mg/dL, albumin of 4.5 g/dL, intact parathormone (iPTH) of 13.3 pg/mL, 25(OH) D3 vitamin of 16.3 µg/L, daily urinary calcium excretion of 23.4 mg/day. Noncontrast computerized tomography (CT) of the brain showed bilateral basal ganglia calcification. Abdominal ultrasonography and CT showed the absence of renal tissue in the left kidney site and pelvis (left renal aplasia). Audiometry revealed mild sensorineural hearing loss at high frequencies. Conclusions. The patients with HDR syndrome are often diagnosed when they are examined for symptomatic hypoparathyroidism and deafness. To the best our knowledge, the present case is the second case of Barakat Syndrome reported from Turkey. The treatment of HDR syndrome is focused on clinical symptoms. The prognosis of the disease correlates with hypoparathyroidism and the severity of renal disease. HDR syndrome has an autosomaldominant inheritance, screening of family members is recommended for early diagnosis and treatment.

Practical Diabetes International, 2004

The case of a 30-year-old woman presenting with diabetic ketoacidosis as a first manifestation of... more The case of a 30-year-old woman presenting with diabetic ketoacidosis as a first manifestation of acromegaly is reported. This is an extremely rare and unusual presentation. The case illustrates the importance of insulin resistance due to growth hormone excess in the presence of relative insulin deficiency as a cause of diabetic ketoacidosis. Copyright © 2004 John Wiley & Sons, Ltd.

Medical Principles and Practice, 2009

Objective: The aim of this study was to assess flow-mediated dilatation (FMD) of the brachial art... more Objective: The aim of this study was to assess flow-mediated dilatation (FMD) of the brachial artery in patients with acromegaly. Subjects and Methods: We prospectively evaluated 25 patients with acromegaly (14 females, 11 males; aged 42 ± 12 years; growth hormone (GH) levels 34 ± 14 ng/ml) and 27 control subjects (15 females, 12 males; aged 45 ± 8 years; GH levels 3 ± 1.5 ng/ml). The patients and controls were matched for age, gender, body mass index, cigarette smoking, blood pressure, lipid levels, diabetes mellitus, hypertension, and its duration. Endothelial function, measured as FMD of the brachial artery using ultrasound, was calculated in the 2 groups. The endothelial function was evaluated by assessing 1-min postischemic FMD of the brachial artery. Results: The FMD was lower in patients with acromegaly (9.97 ± 3.5%) than in controls (16.1 ± 3.4%), and the difference was statistically significant (p = 0.0001). Conclusion: Endothelial dysfunction may develop in the preclinical...

Limnology and Oceanography, 2003

Total and dissolved inorganic phosphorus (IP) was measured in both rainwater and aerosol samples ... more Total and dissolved inorganic phosphorus (IP) was measured in both rainwater and aerosol samples collected from two remote coastal areas: on the island of Crete (Greece) and at Erdemli (Turkey). Particle size distributions of P, as well as total deposition were also measured. Wet and dry deposition of dissolved inorganic phosphorus (DIP) from Crete are compared with simultaneously obtained dissolved inorganic nitrogen (DIN) and with productivity data from the literature. Our results indicate that (1) in both wet and dry deposition, the DIN/DIP molar ratio ranges between 63 and 349, exceeding by a factor of up to 22 the N/P ratio observed in seawater (ranging from 25 to 28) and (2) atmospheric deposition of DIP could reasonably account for a significant part of the new production (up to 38%) observed during the summer and autumn period (i.e., when water stratification is at its maximum).

Global Biogeochemical Cycles, 2005

Multiyear daily surface aerosol aluminum (Al) concentration and sunphotometer measurements at Erd... more Multiyear daily surface aerosol aluminum (Al) concentration and sunphotometer measurements at Erdemli (Turkey) sampling station were used to assess the performance of Absorbing Aerosol Index (AAI) and Aerosol Optical Thickness (AOT) retrieved from the daily Total Ozone Mapping Spectrometer (TOMS) over the northeastern Mediterranean. A total of 98 moderate‐to‐high intensity dust events with durations from 1 day to 1 week were identified by aerosol Al concentrations and/or TOMS‐AAI above their threshold values of 1.0 μg m−3 and 0.5, respectively. Only 15 events were found to bring appreciable dust load into the northeastern Mediterranean, predominantly below the 850‐hPa pressure level, and therefore were not detected effectively by TOMS. Eight of these events corresponded to short‐range high intensity intrusions (Al > 3.0 μg m−3) from nearby dust sources of the Middle East and Arabian deserts, the rest (seven events) represented moderate‐to‐high intensity (Al > 1.0 μg m−3) long‐...

European Journal of Endocrinology, 2009

Background and objectivesPrimary hyperparathyroidism (PHPT) is associated with increased cardiova... more Background and objectivesPrimary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality and morbidity. Little is known about hemostatic features of patients with PHPT. To our knowledge, plasma tissue factor pathway inhibitor (TFPI) and thrombin-activatable fibrinolysis inhibitor (TAFI) levels in these patints have not been investigated. Therefore, the main purpose of this study was to evaluate the markers of endogenous coagulation/fibrinolysis, including TFPI and TAFI, and to investigate the relationships between serum calcium and PTH and these hemostatic parameters in patients with PHPT.Design and methodsTwenty-four patients with PHPT and 20 age-, sex-, and-weight-matched healthy controls were included in the study. Tissue plasminogen activator (t-PA), tissue plasminogen activator inhibitor-1 (PAI-1), TFPI, and TAFI were measured. The relationships between serum calcium, phosphorus, and PTH and these hemostatic parameters were examinated.ResultsCompared wi...

Endocrine Practice, 2000

Objective: To report a case of leukocytoclastic vasculitis as a manifestation of propylthiouracil... more Objective: To report a case of leukocytoclastic vasculitis as a manifestation of propylthiouracil allergy. Methods: We present the history, findings on physical examination, and results of laboratory evaluation in a 25-year-old woman. Associated reports from the literature are reviewed. Results: The patient, with a history of Graves' disease, was referred for evaluation of a purpuric rash on the pinnas and buttocks bilaterally. Findings included exophthalmos and bilateral goiter with neck bruits. She was biochemically hyperthyroid. Biopsy of the skin lesions revealed leukocytoclastic vasculitis. Propylthiouracil therapy was discontinued, and prednisone was prescribed. Treatment with radioactive iodine resulted in appreciably diminished skin lesions and reduction in the size of the thyroid gland, but thyroxine and triiodothyronine levels increased. Administration of a second, higher dose of radioactive iodine with concomitant lithium carbonate resulted in clinical and biochemical improvement. Six months after initial assessment, the rash had resolved, and the patient's free thyroxine value had normalized, although the thyrotropin level was still suppressed. Conclusion: Leukocytoclastic vasculitis, although rarely seen as a manifestation of propylthiouracil allergy, has been reported in the medical literature and should be considered in the differential diagnosis of patients with a vasculitic rash. Treatment consists of discontinuation of the offending medication and administration of a corticosteroid and, occasionally, cyclophosphamide or plasmapheresis.

Clinical Endocrinology, 2009

SummaryObjective Although the strong association between hyperprolactinaemia and platelet aggreg... more SummaryObjective Although the strong association between hyperprolactinaemia and platelet aggregation is well recognized, there are no studies on changes in coagulation and fibrinolytic status in patients with prolactinoma. To our knowledge, tissue plasminogen activator inhibitor‐1 (PAI‐1), plasma tissue factor pathway inhibitor (TFPI) and thrombin‐activatable fibrinolysis inhibitor (TAFI) levels in these patients have not been investigated. Therefore, the main purpose of this study was to evaluate the markers of endogenous coagulation/fibrinolysis, including TFPI and TAFI, and to investigate the relationships between prolactin (PRL) and these haemostatic parameters and serum lipid profile in patients with prolactinoma.Research methods and procedures Twenty‐two patients with untreated, newly diagnosed prolactinoma and 20 age‐matched healthy controls were included in the study. Platelet count, mean platelet volume, prothrombin time, activated partial thromboplastin time, fibrinogen...

Biogeosciences, 2010

Aerosol and rainwater samples have been collected at a rural site located on the coastline of the... more Aerosol and rainwater samples have been collected at a rural site located on the coastline of the Eastern Mediterranean, Erdemli, Turkey between January 1999 and December 2007. Riverine sampling was carried out at five Rivers (Ceyhan, Seyhan, Göksu, Berdan and Lamas) draining into the Northeastern Levantine Basin (NLB) between March 2002 and July 2007. Samples have been analyzed for macronutrients of phosphate, silicate, nitrate and ammonium (PO 3− 4 , Si diss , NO − 3 and NH + 4). Phosphate and silicate in aerosol and rainwater showed higher and larger variations during the transitional period when air flows predominantly originate from North Africa and Middle East/Arabian Peninsula. Deficiency of alkaline material have been found to be the main reason of the acidic rain events whilst high pH values (>7) have been associated with high Si diss concentrations due to sporadic dust events. In general, lowest nitrate and ammonium concentrations in aerosol and rainwater have been associated with air flow from the Mediterranean Sea. Comparison of atmospheric with riverine fluxes demonstrated that DIN and PO 3− 4 fluxes to NLB have been dominated by atmosphere (∼90% and ∼60% respectively) whereas the input of Si was mainly derived from riverine runoff (∼90%). N/P ratios in the atmospheric deposition (233); riverine discharge (28) revealed that NLB receives excessive amounts of DIN and this unbalanced P and N inputs may provoke even more phosphorus deficiency. Observed molar Si/N ratio suggested Si limitation relative to nitrogen might cause a switch from diatom dominated communities to non-siliceous populations particularly at coastal NLB.

Atmospheric Environment, 2012

The impact of ambient temperature on the levels and chemical composition of aerosols over the Eas... more The impact of ambient temperature on the levels and chemical composition of aerosols over the Eastern Mediterranean in July 2004 is investigated using the WRF/CMAQ model system coupled with the MEGAN biogenic emissions model. CMAQ is able to capture the observed mean aerosol concentrations over the studied period. Non-sea-salt sulfate (nss-SO 4 2À) is calculated to be the major aerosol component contributing by 63%, 16% and 40% to the fine (PM 2.5), coarse (PM 2.5e10) and total particulate matter mass (PM 10), respectively. PM 2.5 to PM 10 mass ratios reach more than 80% over the large urban agglomerations but decrease to 45% at downwind locations suggesting coagulation and condensation on coarse particles. Higher temperatures increase biogenic emissions, enhance spatially-averaged biogenic secondary organic aerosol (SOA, by 0.01 AE 0.00 mg m À3 K À1) and nitrate (NO 3 À) aerosol concentrations (by 0.02 AE 0.02 mg m À3 K À1). They reduce nss-SO 4 2À (by À0.04 AE 0.07 mg m À3 K À1), induced by significant reduction in the cloud cover (90% K À1) and subsequent aqueous-phase production. The PM 2.5 concentrations show a very small positive response to temperature changes, increasing by 0.003 AE 0.042 mg m À3 K À1 (0.04% K À1) due to the compensation of organic carbon increases by nss-SO 4 2À reductions. Locally, larger changes are computed, with nss-SO 4 2À and NO 3 À in fine aerosols reduced by up to 0.62 mg m À3 K À1 and 0.80 mg m À3 K À1 , respectively. Increases as high as 0.097 mg m À3 K À1 and 0.034 mg m À3 K À1 are calculated for organic and elemental carbon, respectively. Results show that changes in temperature modify not only the aerosol mass but also its chemical composition.

Atmospheric Environment, 2013

h i g h l i g h t s Atmospheric N and S depositions over Mediterranean and Black seas are simulat... more h i g h l i g h t s Atmospheric N and S depositions over Mediterranean and Black seas are simulated. N transported from upwind sources is deposited over the Mediterranean. Dry deposition dominates over wet deposition in Mediterranean and Black Sea. Atmospheric N inputs are comparable to N export in Black and W. Mediterranean seas. Atmospheric N input exceeds the N export in the East Mediterranean Sea.

Atmospheric Environment, 2003

Weekly PM 2.5 samples were collected in Shanghai, China at two sites, Tongji University and Haina... more Weekly PM 2.5 samples were collected in Shanghai, China at two sites, Tongji University and Hainan Road. Sampling started in March 1999 and was conducted for 1 year. The ambient mass concentration and chemical composition of the PM 2.5 were determined. Chemical analyses included elemental composition, water-soluble ions, and organic and elemental carbon. Weekly PM 2.5 mass concentrations ranged from 21 to 147 mg/m 3 , with annual average concentrations of 57.9 and 61.4 mg/m 3 at the two sites, respectively. Seasonal variation of PM 2.5 concentrations was significant, with the highest concentrations observed from mid-November through December and the lowest from June through September. Ammonium sulfate and nitrate accounted for 41.6% of the PM 2.5 mass with sulfate alone accounting for 23.4% of the PM 2.5 mass. Carbonaceous material accounted for 41.4% of the PM 2.5 mass, with 73% of that mass being organic, as defined by the TOR analysis method. Crustal components averaged 9.6% of the PM 2.5 mass. Potassium, which was 95% water soluble, accounted for 2.7% of the PM 2.5 mass.

Atmospheric Environment, 2007

Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days,... more Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust measurements demonstrated that the region is routinely impacted by dust generated regionally and from North Africa and that the highest combined percent recovery of total CFU and African dust deposition occurred in the month of April (93.4% of CFU recovery and 91.1% of dust deposition occurred during African dust days versus no African dust present, for that month). A statistically significant correlation was observed (peak regional African dust months of March, April and May; r s ¼ 0.576, P ¼ 0.000) between an increase in the prevalence of microorganisms recovered from atmospheric samples on dust days (regional and African as determined by ground-based dust measurements), versus that observed on non-dust days. Given the prevalence of atmospherically suspended desert dust and microorganisms observed in this study, and that culture-based studies typically only recover a small fraction (o1.0%) of the actual microbial population in any given environment, dust-borne microorganisms and other associated constituents (organic detritus, toxins, etc.) may play a significant role in the regional human and ecosystem health.