Clinical Utility of Serum C-Peptide Concentration for Hospitalized Patients with Hyperglycemia.

Background: Serum C-peptide concentration is often utilized for diagnostic, prognostic, or therapeutic assessment in diabetes mellitus. However, there are limited clinical data regarding diagnostic and predictive value of C-peptide measured during hospitalizations for hyperglycemia. Materials and Methods: Adults admitted to Mayo Clinic inpatient facilities due to an acute hyperglycemic emergency between January 2017 and November 2022 were included in our study. Predictive capacity of C-peptide for discontinuation of therapeutic insulin was examined in the entire cohort and the subgroup of non-autoimmune non-pancreatitis diabetes (NANP-DM). Results: We included 187 patients (63 women) in our study. During hospitalization, patients with type 1 diabetes antibodies displayed diminished serum C-peptide concentration (P = 0.014), correlating inversely with subsequent hemoglobin A1c% [r = (-0.22), P = 0.005]. Initial C-peptide concentrations did not differ between patients requiring insulin therapy during follow-up and those who did not (P = 0.16). C-peptide concentrations showed limited predictive capacity for achieving glycemic control. Subgroup analyses in NANP-DM exhibited similar limited capacity for anticipating therapeutic insulin needs and achieving glycemic controls. Discussion: C-peptide concentration did not exhibit a robust predictive capability for future need of insulin therapy and achieving glycemic control, limiting its utility in clinical practice within inpatient settings.

Assessment of metal element concentrations in mussel (M. Galloprovincialis) in Eastern Black Sea, Turkey.

The main goal of this work is to determine the effects of pollution of copper, lead and zinc mines on the Eastern Black Sea. Metal and heavy metal concentrations in the Eastern Black Sea mussels were measured using Energy Dispersive X-ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectroscopy (FAAS). The analytical results showed that the tissue of mussel in Eastern Black Sea contains K, Ca, Fe, Cu, Zn, and Sr elements, and the shell of mussel contains Ca, Cu, Sr, and Ba elements. Due to the detection limit of EDXRF, the mussels were analyzed with FAAS for Cr, Mn, Ni, Cd and Pb elements. An ANOVA and Pearson correlation analyses were performed. The results showed although that the mean concentrations of Cu and Zn for the tissue of the mussels were markedly above the permissible levels of the Turkish regulations, Zn concentration is in the limits of the Food and Agriculture Organization (FAO).

Gross alpha and beta activities in tap waters in Eastern Black Sea region of Turkey.

Gross alpha and gross beta activities were determined for 27 different tap water samples collected from Eastern Black Sea region of Turkey. The instrumentation used to count the gross alpha and gross beta activities was a alpha/beta counter of the low background multiple detector type with 10 sample detectors (Berthold LB770). The obtained results showed that natural activity concentrations of alpha- and beta-emitting radionuclides in tap water samples did not exceed WHO and ITS recommended levels. Concentrations ranging from 0.2 mBq/l to 15 mBq/l and from 25.2 mBq/l to 264.4 mBq/l were observed for the gross alpha and gross beta activities, respectively. For all samples the gross beta activities were higher than the corresponding gross alpha activities.

Natural radioactivity in tap waters of Eastern Black Sea region of Turkey.

In this study, the activity concentrations of some radionuclides in tap water samples of the Eastern Black Sea region of Turkey were measured. The activity concentrations of radionuclides (214)Pb, (214)Bi, (40)K, (226)Ra and (137)Cs were determined using high resolution gamma ray spectrometry. Furthermore, (222)Rn activity concentrations in tap water samples were measured using Liquid Scintillation Counting. The mean specific activities of (214)Pb, (214)Bi, (226)Ra, (40)K, (137)Cs and (222)Rn in tap water samples were 6.73, 6, 19.16, 168.57, 5.45 mBq l(-1) and 10.82 Bq l(-1), respectively. These values are comparable with concentrations reported for other countries. The effective doses were determined due to intake of these radionuclides as a consequence of direct consumption of tap water samples. The estimated effective doses were 6.878 x 10(-4) microSv y(-1) for (214)Pb, 4.800 x 10(-4) microSv y(-1) for (214)Bi, 3.916 microSv y(-1) for (226)Ra, 0.763 microSv y(-1) for (40)K, 0.052 microSv y(-1) for (137)Cs and 5.848 microSv y(-1) for (222)Rn.

Radiological maps in beach sands along some coastal regions of Turkey.

In the present research, the gamma-emitting radionuclides in beach sands along the coastal regions of the Ordu, Giresun and Trabzon provinces, Turkey have been determined. The natural and anthropogenic radionuclide concentrations of the samples have been measured employing a germanium (HPGe) detector with high resolution and purity. The activity for 238U, 232Th, 40K and 137Cs of the samples were found to vary in the range from below detection limit (BDL) to 65Bq·kg-1, from BDL to 28Bq·kg-1, from 9 to 1936Bq·kg-1 and from BDL to 22Bq·kg-1, respectively. The activity concentrations were compared with those in the literature. The associated radiological hazard indices were estimated, and were compared to the internationally recommended values. The radiological map of beach sand in the surveyed area was imaged. The data presented in the study are crucial since they constitute a baseline for the radiological mapping of the region in the future.

Calculation of radiation attenuation coefficients, effective atomic numbers and electron densities for some building materials.

Some building materials, regularly used in Turkey, such as sand, cement, gas concrete (lightweight, aerated concrete), tile and brick, have been investigated in terms of mass attenuation coefficient (µ/ρ), effective atomic, numbers (Z(eff)), effective electron densities (N(e)) and photon interaction cross section (σ(a)) at 14 different energies from 81- to 1332-keV gamma-ray energies. The gamma rays were detected by using gamma-ray spectroscopy, a High Purity Germanium (HPGe) detector. The elemental compositions of samples were analysed using an energy dispersive X-ray fluorescence spectrometer. Mass attenuation coefficients of these samples have been compared with tabulations based upon the results of WinXcom. The theoretical mass attenuation coefficients were estimated using the mixture rule and the experimental values of investigated parameters were compared with the calculated values. The agreement of measured values of mass attenuation coefficient, effective atomic numbers, effective electron densities and photon interaction cross section with the theory has been found to be quite satisfactory.

A study of environmental radioactivity measurements in the Samsun province, Turkey.

This study was concerned with the measurement of natural and artificial radionuclides in soil samples and indoor radon concentrations in the Samsun province, Turkey. In soil samples, the values of individual mean activity of (226)Ra, (232)Th, (40)K and (137)Cs radionuclides were found to be 31, 22, 341 and 16 Bq kg(-1), respectively. The radiological parameters, such as the absorbed dose rate in air, the annual effective dose (AED) and excess lifetime cancer risk, were calculated. Indoor radon measurements were carried out with CR-39-based radon dosemeters at 127 dwellings in the Samsun province. The mean annual (222)Rn activity was found to be 106 Bq m(-3) (equivalent to an AED of 1.88 mSv). The seasonal variation of (222)Rn activity shows that maximum levels are observed in the winter, while minimum levels are observed in the summer. The mean lifetime fatality risk for the studied area was estimated at 1.45×10(-4). The results obtained did not significantly differ from those obtained in other parts of the country.

Radiological maps for Trabzon, Turkey.

The activity concentrations and absorbed gamma dose rates due to primordial radionuclides and (137)Cs have been ascertained in 222 soil samples in 18 counties of the Trabzon province of Turkey using a HPGe detector. The mean activity concentrations of (238)U, (232)Th, (40)K and (137)Cs in soil samples were 41, 35, 437 and 21 Bq kg(-1), respectively. Based on the measured concentrations of these radionuclides, the mean absorbed gamma dose in air was calculated as 59 nGy h(-1) and hence, the mean annual effective dose due to terrestrial gamma radiation was calculated as 72 µSv y(-1). In addition, outdoor in situ gamma dose rate (D) measurements were performed in the same 222 locations using a portable NaI detector and the annual effective dose was calculated to be 66 µSv y(-1) from these results. The results presented in this study are compared with other parts of Turkey. Radiological maps of the Trabzon province were composed using the results obtained from the study.

Radiological and chemical assessment of phosphate rocks in some countries.

In this study, the radiological, structural and chemical characterizations of Mardin-Mazidagi phosphate rock, which is an important phosphate fertilizer source in Turkey were investigated and compared to those of several different phosphate rocks of Tunisia, Egypt, Morocco, Algeria and Syria using gamma spectrometry, X-ray diffraction (XRD) and X-ray fluorescence (XRF) measurement techniques. Elemental analysis results of phosphate samples showed that they were mainly composed of CaO, P(2)O(5), SiO(2), Al(2)O(3), SO(3) and Fe(2)O(3). Elemental concentrations of U and Th were calculated using (226)Ra and (232)Th activity concentrations, respectively. As a result of XRD analysis, the main peaks of the samples were found to be Fluorapatite (Ca(5)(PO(4))(3)F). The radioactivity concentration levels for (226)Ra, (232)Th and (40)K in all phosphate samples ranged from 250 to 1029 Bq kg(-1) with a mean of 535 Bq kg(-1), from 5 to 50 Bq kg(-1) with a mean of 20 Bq kg(-1) and from 117 to 186 Bq kg(-1) with a mean of 148 Bq kg(-1), respectively. The computed values of annual effective doses ranged from 0.17 to 0.59 mSv, with a mean value of 0.33 mSv, which is lower than the recommended limit of 1 mSv y(-1) by the International Commission on Radiological Protection.

Radiation dose estimation and mass attenuation coefficients of cement samples used in Turkey.

Different cement samples commonly used in building construction in Turkey have been analyzed for natural radioactivity using gamma-ray spectrometry. The mean activity concentrations observed in the cement samples were 52, 40 and 324 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and world average limits. The radiological hazard parameters such as radium equivalent activities (Ra(eq)), gamma index (I(gamma)) and alpha index (I(alpha)) indices as well as terrestrial absorbed dose and annual effective dose rate were calculated and compared with the international data. The Ra(eq) values of cement are lower than the limit of 370 Bq kg(-1), equivalent to a gamma dose of 1.5 mSv y(-1). Moreover, the mass attenuation coefficients were determined experimentally and calculated theoretically using XCOM in some cement samples. Also, chemical compositions analyses of the cement samples were investigated.

Radioactivity and heavy metal levels in hazelnut growing in the Eastern Black Sea Region of Turkey.

The Eastern Black Sea Region of Turkey is one of the main hazelnut producers in Turkey and in the world. Since this region was contaminated by the Chernobyl accident in 1986, a comprehensive study was planned and carried out to determine the radioactivity level in hazelnut growing region. The dose due to consumption of hazelnut by the public was estimated and it was shown that this dose imposes no threat to human health. In addition, heavy metal analysis was performed in the samples and the amount of Cr, Mn, Fe, Ni, Cu, Zn, and Pb were also detected. The results showed that the concentrations of heavy metal are below the daily intake recommended by the international organizations.

Environmental radioactivity assessment for Bayburt, Turkey.

This study assesses the results of environmental radioactivity measurements for Bayburt Province in the Eastern Black Sea area of Turkey. Using gamma-ray spectrometry, activity concentrations of the natural radionuclides (226)Ra, (232)Th and (40)K and a fission product (137)Cs were investigated in soil samples. The activity concentrations of (226)Ra, (232)Th and (40)K in various building materials such as sand, cement and marble and in drinking waters were determined. The activity concentrations vary from 16 to 54 Bq kg(-1) for (226)Ra, from 10 to 21 Bq kg(-1) for (232)Th and from 113 to 542 Bq kg(-1) for (40)K in building materials. The mean specific activity concentrations of (226)Ra, (232)Th and (40)K in drinking waters were 93, 30 and 504 mBq l(-1), respectively. The concentrations of gross alpha and beta radioactivity in drinking water samples collected from four different sampling stations have been determined. The results show that the gross alpha and beta activities are lower than the screening levels given by the World Health Organization (WHO), which are a maximum contaminant level of 0.5 Bq l(-1) and 1.0 Bq l(-1) gross alpha and beta radioactivity, respectively, in drinking water. Indoor radon measurements were made in 44 dwellings in Bayburt by using Cr-39 detectors. Radon concentrations in dwellings in Bayburt varied from 17 to 125 Bq m(-3) and the average value was 56 Bq m(-3). The results obtained in this study indicate that the region has a background radiation level that is within the typical natural range and shows no significant departures from other parts of the country.

Assessment of natural radioactivity of sand used in Turkey.

The natural radioactivity due to the presence of (226)Ra, (232)Th and (40)K in sand samples used as building materials in Turkey was measured by gamma spectrometry. The measured activity in the sand samples ranged from 17 to 97 Bq kg(-1), 10 to 133 Bq kg(-1) and 116 to 955 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The concentrations of these natural radionuclides were compared with the reported data for other countries. The radium equivalent activity (Ra(eq)), the external hazard index (H(ex)), the internal hazard index (H(in)), the indoor absorbed dose rate in air and the annual effective dose rate were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. The Ra(eq) values of sand samples are lower than the limit of 370 Bq kg(-1), equivalent to a gamma dose of 1.5 mSv yr(-1). This study shows that the measured sand samples do not pose any significant source of radiation hazard and are safe for use in building materials. Moreover, the experimental mass attenuation coefficients (mu/rho) of seven different sand samples were determined in the energy range 80-1332 keV photons by using the gamma ray transmission method. Experimental values of mass attenuation coefficient were compared with theoretical values obtained using the program XCOM. The calculated values and the experimental results of this work and the other results in the literature are found to be in good agreement. Chemical and structural analyses (XRD) of the sand samples were also undertaken.

Characterization of gas concrete materials used in buildings of Turkey.

The activity concentration of (226)Ra, (232)Th and (40)K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg(-1), equivalent to a gamma-dose of 1.5 mSv y(-1). Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated.

Radioactive contamination in lichens collected from Trabzon and Rize in the Eastern Black Sea Region, Turkey, and a comparison with that of 1995.

After the Chernobyl nuclear accident in 1986, 14 lichen specimens collected from Trabzon and Rize in 1995 were used to detect the amount of the fallout radionuclides. In this paper, radioactivity levels in the same species from the same localities were re-detected to compare with those of 1995. According to the results of the two studies, the radioactivity levels that this paper found for 137Cs and 40K are significantly lower than those of 1995 (about 5.5-127 folds for 137Cs, 5-17 folds for 40K). The level of 212Pb was acceptably small. The highest activities of the lichen species are seen in the locality of Helvaci (Trabzon, 100 m) and Camlihemsin (Rize, 1850 m) while the activities are medium in Bozdogan (Trabzon, 150 m), Kemaliye (Trabzon, 750 m) and Camlihemsin (Rize, 900 m). The activity values generally increase significantly depending on the altitudes. Since the measurements were performed 20 years after the Chernobyl accident in 1986, radionuclides of 134Cs having short half-life (2.062 y) have not been detected. All data was obtained with a coaxial high purity Ge detector of 15% relative efficiency and resolution 1.9 keV at the 1332 keV gamma of 60Co (Canberra, GC 1519 model).