Investigation of natural and artificial radioactivity levels in travertines of the Cappadocia region in Turkey

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayası regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayası. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg-1 for 232Th, 4.21 to 13.41 Bq kg-1 for 40K, and 0.42-3.26 Bq kg-1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).

Hormonal changes in the first 24 postoperative hours after cardiac surgical procedures

Background

Hormone level changes after heart surgeries are a widely observed phenomenon due to neurohormonal feedback mechanisms that may affect postoperative morbidity and mortality. The current study aimed to analyze the changes in thyroid and sex hormones in the first 24 postoperative hours after heart surgery.

Methods

This prospective, observational study (registered on ClinicalTrials.gov: NCT03736499; 09/11/2018) included 49 patients who underwent elective cardiac surgical procedures at a tertiary heart center between March 2019 and December 2019. Thyroid hormones, including thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4), and sex hormones, including prolactin (PRL) and total testosterone, were measured preoperatively and at 24 h postoperatively.

Results

Significant decreases in serum TSH (P < 0.001), T3 (P < 0.001) and total testosterone (P < 0.001) levels were noted, whereas T4 (P = 0.554) and PRL (P = 0.616) did not significantly change. Intensive care unit (ICU) hours (P < 0.001), mechanical ventilation (P < 0.001) and Vasoactive-Inotropic Score (VIS) (P = 0.006) were associated with postoperative T3 level. ICU hours were associated with postoperative T4 level (P = 0.028). Postoperative and delta testosterone levels were in connection with lengths of stay in ICU (P = 0.032, P = 0.010 respectively). Model for End-Stage Liver Disease (MELD) scores were associated with thyroid hormone levels and serum testosterone.

Conclusions

T3 may represent a marker of nonthyroidal illness syndrome and testosterone may reflect hepatic dysfunction. In addition, PRL may act as a stress hormone in female patients.

Comprehensive frailty assessment with multidimensional frailty domains as a predictor of mortality among vascular and cardiac surgical patients

Purpose

The frailty concept has become a fundamental part of daily clinical practice. In this study our purpose was to create a risk estimation method with a comprehensive aspect of patients' preoperative frailty.

Patients and methods

In our prospective, observational study, patients were enrolled between September 2014 and August 2017 in the Department of Cardiac Surgery and Department of Vascular Surgery at Semmelweis University, Budapest, Hungary. A comprehensive frailty score was built from four main domains: biological, functional-nutritional, cognitive-psychological and sociological. Each domain contained numerous indicators. In addition, the EUROSCORE for cardiac patients and the Vascular POSSUM for vascular patients were calculated and adjusted for mortality.

Results

Data from 228 participants were included for statistical analysis. A total of 161 patients underwent vascular surgery, and 67 underwent cardiac surgery. The preoperatively estimated mortality was not significantly different (median: 2.700, IQR (interquartile range): 2.000-4.900 vs. 3.000, IQR: 1.140-6.000, P = 0.266). The comprehensive frailty index was significantly different (0.400 (0.358-0.467) vs. 0.348 (0.303-0.460), P = 0.001). In deceased patients had elevated comprehensive frailty index (0.371 (0.316-0.445) vs. 0.423 (0.365-0.500), P < 0.001). In the multivariate Cox model an increased risk for mortality in quartiles 2, 3 and 4 compared with quartile 1 as a reference was found (AHR (95% CI): 1.974 (0.982-3.969), 2.306 (1.155-4.603), and 3.058 (1.556-6.010), respectively).

Conclusion

The comprehensive frailty index developed in this study could be an important predictor of long-term mortality after vascular or cardiac surgery. Accurate frailty estimation could make the traditional risk scoring systems more accurate and reliable.

Association between Hepatic Venous Congestion and Adverse Outcomes after Cardiac Surgery

INTRODUCTION

Hepatic venous flow patterns reflect pressure changes in the right ventricle and are also markers of systemic venous congestion. Fluid management is crucial in patients undergoing cardiac surgery.

METHODS

Our goal was to determine which factors are associated with the increased congestion of the liver as measured by Doppler ultrasound in patients undergoing cardiac surgery. This prospective, observational study included 41 patients without preexisting liver disease who underwent cardiac surgery between 1 January 2021 and 30 September 2021 at a tertiary heart center. In addition to routine echocardiographic examination, we recorded the maximal velocity and velocity time integral (VTI) of the standard four waves seen in the common hepatic vein (flow profile) using Doppler ultrasound preoperatively and at the 20-24th hour of the postoperative period. The ratios of the retrograde and anterograde hepatic venous waves were calculated, and the waveforms were compared to the baseline value and expressed as a delta ratio. Demographic data, pre- and postoperative echocardiographic parameters, intraoperative variables (procedure, cardiopulmonary bypass time), postoperative factors (fluid balance, vasoactive medication requirement, ventilation time and parameters) and perioperative laboratory parameters (liver and kidney function tests, albumin) were used in the analysis.

RESULTS

Of the 41 patients, 20 (48.7%) were males, and the median age of the patients was 65.9 years (IQR: 59.8-69.9 years). Retrograde VTI growth showed a correlation with positive fluid balance (0.89 (95% CI 0.785-0.995) c-index. After comparing the postoperative echocardiographic parameters of the two subgroups, right ventricular and atrial diameters were significantly greater in the "retrograde VTI growth" group. The ejection fraction and decrement in ejection fraction to preoperative parameters were significantly different between the two groups. (p = 0.001 and 0.003). Ventilation times were longer in the retrograde VTI group. The postoperative vs. baseline delta VTI ratio of the hepatic vein correlated with positive fluid balance, maximum central venous pressure, and ejection fraction. (B = -0.099, 95% CI = -0.022-0.002, p = 0.022, B = 0.011, 95% CI = 0.001-0.021, p = 0.022, B = 0.091, 95% CI = 0.052-0.213, p = 0.002, respectively.) Conclusion: The increase of the retrograde hepatic flow during the first 24 h following cardiac surgery was associated with positive fluid balance and the decrease of the right ventricular function. Measurement of venous congestion or venous abdominal insufficiency seems to be a useful tool in guiding fluid therapy and hemodynamic management.

Association between Preoperative Retrograde Hepatic Vein Flow and Acute Kidney Injury after Cardiac Surgery

Key questions: Is there a predictive value of hepatic venous flow patterns for postoperative acute kidney injury (AKI) after cardiac surgery? Key findings: In patients who underwent cardiac surgery, retrograde hepatic venous waves (A, V) and their respective ratio to anterograde waves showed a strong association with postoperative AKI, defined as the percentage change of the highest postoperative serum creatinine from the baseline preoperative concentration (%ΔCr). The velocity time integral (VTI) of the retrograde A wave and the ratio of the retrograde and anterograde waves’ VTI were independently associated with AKI after adjustment for disease severity. Take-home message: A higher ratio of retrograde/antegrade waves in hepatic venous retrograde waves, which are related to hepatic stasis, may predict AKI after cardiac surgery. Introduction: Hepatic venous flow patterns reflect pressure changes in the right ventricle and are also markers of systemic venous congestion. Pulsatility of the inferior caval vein was used to predict the risk of acute kidney injury (AKI) after cardiac surgery. Aims: Our objective was to evaluate the association between preoperative hepatic venous flow patterns and the risk of AKI in patients after cardiac surgery. Methods: This prospective, observational study included 98 patients without preexisting liver disease who underwent cardiac surgery between 1 January 2018, and 31 March 2020, at a tertiary heart center. In addition to a routine echocardiographic examination, we recorded the maximal velocity and velocity time integral (VTI) of the standard four waves in the common hepatic vein with Doppler ultrasound. Our primary outcome measure was postoperative AKI, defined as the percentage change of the highest postoperative serum creatinine from the baseline preoperative concentration (%ΔCr). The secondary outcome was AKI, defined by KDIGO (Kidney Disease Improving Global Outcomes) criteria. Results: The median age of the patients was 69.8 years (interquartile range [IQR 25−75] 13 years). Seventeen patients (17.3%) developed postoperative AKI based on the KDIGO. The VTI of the retrograde A waves in the hepatic veins showed a strong correlation (B: 0.714; p = 0.0001) with an increase in creatinine levels after cardiac surgery. The velocity time integral (VTI) of the A wave (B = 0.038, 95% CI = 0.025−0.051, p < 0.001) and the ratio of VTI of the retrograde and anterograde waves (B = 0.233, 95% CI = 0.112−0.356, p < 0.001) were independently associated with an increase in creatinine levels. Conclusions: The severity of hepatic venous regurgitation can be a sign of venous congestion and seems to be related to the development of AKI.

Preoperative nutritional state is associated with mid- and long-term mortality after cardiac surgery

BACKGROUND

The frailty score has been developed to determine physiological functioning capacity. The aim of our research was to explore the relationship between frailty factors and mortality in cardiac surgery patients.

METHODS

Our research is an observational, single-center, prospective cohort study (registered on ClinicalTrials.gov: NCT02224222), and we studied 69 patients who underwent elective cardiac surgery between 2014 and 2017. Thirty days before the surgery, they completed a questionnaire that contained questions related to social support, self-reported life quality-happiness, cognitive functions, anxiety and depression. Demographic, anthropometric and medical data were widely collected. The Geriatric Nutritional Risk Index (GNRI) and the Comprehensive Geriatric Assessment (CGA)-based frailty index were calculated as a sum and the domains, respectively. Cox regression and the Kaplan-Meier tests were applied to analyze survival and relative risk. The primary outcome was mid-term mortality.

RESULTS

The patients' mean age was 65.43 years [standard deviation (SD): 9.81 years]. The median followup was 1,656 days of survival [interquartile range (IQR), 1,336-2,081 years], during this period 14 patients died. The median of EuroSCORE II was 1.56 (1.00-2.58) points. The median preoperative albumin level was 32.80 g/L (IQR, 29.9-35.8 g/L). Major adverse cardiovascular and cerebral events (MACCEs) occurred 7 times during follow-up. The nutrition score of the CGA was significantly associated with worse long-term survival [score; hazard ratio (HR): 5.35; 95% CI: 1.10-25.91, P=0.037]. After adjustment for EuroSCORE II and postoperative complications the noncardiovascular CGA score was associated with overall mortality [adjusted hazard ratio (AHR): 1.44, 95% CI: 1.02-2.04, P=0.036]. In the multivariable Cox regression, GNRI <91 showed an increased risk for mortality (AHR: 4.76, 95% CI: 1.52-14.92, P=0.007).

CONCLUSIONS

The CGA-based noncardiovascular score and nutritional status should be assessed before cardiac surgery prehabilitation and may help decrease long-term mortality.

The effect of cognitive dysfunction on mid- and long-term mortality after vascular surgery

Background

In recent decades, previous studies have noted the importance of frailty, which is a frequently used term in perioperative risk evaluations. Psychological and socioeconomical domains were investigated as part of frailty syndrome. The aim of this study was to assess the importance of these factors in mortality after vascular surgery.

Methods

In our prospective, observational study (ClinicalTrials.gov Identifier: NCT02224222), we examined 164 patients who underwent elective vascular surgery between 2014 and 2017. At the outpatient anaesthesiology clinic, patients completed a questionnaire about cognitive functions, depression and anxiety, social support and self-reported quality of life were assessed using a comprehensive frailty index, in addition to medical variables. Propensity score matching was performed to analyse the difference between patients and controls in a nationwide population cohort. The primary outcome was 4 year mortality. The Kaplan-Meier method and Cox regression analysis were used for statistical analyses.

Results

The patients’ mean age was 67.05 years (SD: 9.49 years). Mini-Mental State Examination scores of less than 27 points were recorded for 41 patients. Overall mortality rates were 22.4 and 47.6% in the control and cognitive impairment groups, respectively (p = 0.013). In the univariate Cox regression analysis, cognitive impairment measured using age- and education-adjusted MMSE scores increased the risk of mortality (AHR: 2.842, 95% CI: 1.389-5.815, p = 0.004).

Conclusion

Even mild cognitive dysfunction measured preoperatively using the MMSE represents a potentially important risk factor for mortality after vascular surgery.

Recent results for the one-proton transfer reaction in the 18O+48Ti collision at 275 MeV

The 18O+48Ti reaction was studied at the energy of 275 MeV for the first time under the NUMEN and NURE experimental campaigns with the aim to investigate the complete net of reaction channels potentially involved in the 48Ca→48Ti double charge exchange transition. Such a transition is of great interest because of its relevance to the extraction of 48Ca→48Ti double beta decay nuclear matrix element. The relevant experiment was carried out at the MAGNEX facility of INFN-LNS in Catania. Angular distribution measurements for the various reaction products were performed by using the MAGNEX large acceptance magnetic spectrometer. The present contribution is focused on the analysis of the one-proton transfer channel with emphasis on the particle identification technique and the estimation of background contaminations.

Perioperative Low Tetraiodothyronine Levels and Adverse Outcomes After Heart Transplantation: A Retrospective, Observational Study

OBJECTIVES

Thyroid dysfunction has been shown to be associated with increased all-cause mortality and severity of chronic heart failure in critical illness and severe cardiac diseases. The present study was conducted to ascertain the relationship between perioperative free triiodothyronine and free tetraiodothyronine (fT4) levels and postoperative adverse outcomes after heart transplantation (HTX).

DESIGN

Retrospective, observational study.

SETTING

Single-center study in a quaternary care university clinical center.

PARTICIPANTS

The study comprised adult patients who underwent HTX between 2015 and 2019 and had at least 1 perioperative thyroid hormone laboratory test on the day of surgery or in the 24 hours before/after the procedure (free triiodothyronine, fT4, and thyroid-stimulating hormone).

INTERVENTIONS

No interventions were applied.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was primary graft dysfunction (PGD), defined by the consensus conference of the International Society for Heart and Lung Transplantation. A total of 151 patients were included in the final analyses. Twenty-nine (19.2%) patients had PGD. Fourteen (9.3%) patients had low fT4 levels. An independent association was found between fT4 and PGD (odds ratio 6.49; 95% confidence interval 2.26-18.61; p = 0.001), with adjusted multivariate Cox regression models.

CONCLUSION

The perioperative fT4 level could be a prognostic marker of adverse outcomes in HTX. The authors suggest appropriate perioperative monitoring of fT4 levels. Additional research is warranted to examine the optimal timing, dosage, and method of replacement.

Model for end-stage liver disease scores in veno-arterial extracorporeal membrane oxygenation

INTRODUCTION

Veno-arterial extracorporeal membrane oxygenation is a valuable therapeutic approach in patients with severe heart failure due to different etiologies. Current prognosis with veno-arterial extracorporeal membrane oxygenation is unsatisfactory, and the risk stratification is still challenging. Therefore, we aimed to evaluate the predictive value of different baseline model for end-stage liver disease scores for survival in patients with veno-arterial extracorporeal membrane oxygenation.

METHODS

We conducted an observational, retrospective study of consecutive veno-arterial extracorporeal membrane oxygenation-treated patients between January 2012 and August 2018. The four types of model for end-stage liver disease scores-model for end-stage liver disease, international normalized ratio-excluded model for end-stage liver disease, modified model for end-stage liver disease, and model for end-stage liver disease with sodium-were calculated preoperatively. Veno-arterial extracorporeal membrane oxygenation was used based on the four clinical indications: primer graft failure after heart transplantation, weaning failure from cardiopulmonary bypass, acute myocardial infarction with refractory cardiogenic shock, and bridge to transplantation or bridge to candidacy. The primary endpoint of the study was overall mortality. The secondary endpoint was in-hospital mortality. We performed univariable and multivariable Cox regression analyses.

RESULTS

Data from 135 patients were analyzed. The median follow-up was 952 days (interquartile range = 417-1555 days). In-hospital mortality was 62.2%, and overall mortality was 71.1%. The multivariable Cox regression analysis is adjusted for indication, and the survival after veno-arterial extracorporeal membrane oxygenation score showed that the following scores were associated with overall mortality: model for end-stage liver disease (hazard ratio = 1.04; 95% confidence interval = 1.01-1.07; p = 0.016), modified model for end-stage liver disease (hazard ratio = 1.04; 95% confidence interval = 1.01-1.06; p = 0.006), and model for end-stage liver disease with sodium (hazard ratio = 1.05; 95% confidence interval = 1.02-1.08; p = 0.001).

CONCLUSION

Model for end-stage liver disease, modified model for end-stage liver disease, and model for end-stage liver disease with sodium scores could be useful in the risk stratification of veno-arterial extracorporeal membrane oxygenation treatment in varying clinical indications.

Determination of self-attenuation correction factor for lichen samples by using gamma-ray spectrometry

In this study, we determine the self attenuation correction factor for lichen samples collected from Erzurum, a city located in the eastern region of Turkey by using gamma-ray spectrometry. The self attenuation correction factor is calculated for 17 lichen samples with densities ranging from 0.683 g/cm3 to 0.886 g/cm3. The transmission method has been used to obtain self-attenuation correction factors. Self attenuation correction factor versus energy fit curve is presented. It is observed that self attenuation correction factor changes with density. At lower energies the self-attenuation correction factor has higher values. At higher energies it has smaller values and tends to become stable.

Determination of activity concentration of natural and artificial radionuclides in sand samples from mediterranean coast of Antalya in Turkey

In this paper, we attempt to determine the activity concentration of natural and artificial radionuclides in 37 sand samples from the Mediterranean coast of Antalya in Turkey by using a high purity Germanium (HpGe) detector. 238U, 232Th, 40K and 137Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard index of sand samples are determined res-pectively. The average values are 13.43 ± 0.21 Bq/kg, 6.96 ± 0.06 Bq/kg and, 122.46 ± 18.58 Bq/kg, for 238U, 232Th and 40K respectively. Most of the activity concentration values are less than below minimum detection limit for 137Cs. The average values of the absorbed dose rate D (nGy/h), annual effective dose equivalent AEDE(μSv/y), radium equivalent activity Raeq (Bq/kg), external hazard index Hex and internal hazard index Hin are 15.52 nGy/h, 19.03 μSv/y, 32.81 Bq/kg, 0.09 and 0.12 respectively. It is observed that 238U, 232Th, 40K and 137Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity are in the limit of the published values, external and internal hazard index values are less than unity.

Retrograde continuous warm blood cardioplegia: maintenance of myocardial homeostasis in humans

Recent clinical reports have suggested that continuous delivery of oxygenated warm blood cardioplegia through the coronary veins (retrograde cardioplegia) produces good myocardial preservation during aortic cross-clamping. No data exist, however, about actual myocardial metabolism/homeostasis during retrograde warm blood cardioplegia. We studied 100 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement, or both who received retrograde continuous warm blood cardioplegia (4:1 dilution) during aortic cross-clamping for 54 to 174 minutes. We measured pH, oxygen tension, carbon dioxide tension, HCO3, base excess, and oxygen content of the inflow cardioplegia and the blood egressing from coronary arteries during each arteriotomy for bypass grafting (arteries act as postcapillary veins with retrograde cardioplegia) or the left and right coronary orifices during aortic valve replacement. We also measured these variables from the coronary sinus effluent 1 minute after release of the aortic cross-clamp. Retrograde cardioplegia flow ranged from 50 to 250 mL/min (mean flow, 150 mL/min). All patients were maintained at normothermia during bypass. A total of 460 samples were analyzed (4.6 per patient). Neither the duration of aortic cross-clamping nor the artery sampled affected myocardial blood gases. The pH dropped from 7.41 +/- 0.05 for the inflow cardioplegia to 7.32 +/- 0.1 when sampled from coronary arteries, and the oxygen tension fell from 181 +/- 25 to 28 +/- 5 mm Hg, respectively. Carbon dioxide tension rose from 31.0 +/- 4.1 to 41.4 +/- 9.8 mm Hg. Coronary sinus blood gases 1 minute after cross-clamp removal showed no acidosis or oxygen debt.(ABSTRACT TRUNCATED AT 250 WORDS)