Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China

BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.

The Cumulative Method for Multiplication and Division

This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularly multiplication and division. The operations of multiplication and division are represented by algebraic formulas. An advantage of the method is that the cumulative process can be performed on decimal numbers. The present paper aims to establish a basic and useful formula valid for the two fundamental arithmetic operations of multiplication and division. The new cumulative method proved to be more flexible and made it possible to extend the multiplication and division based on repeated addition/subtraction to decimal numbers.

Study on cumulative effects of biological craniocerebral trauma under repeated blast

Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects and cumulative effects of repeated blasts.Therefore,rats were used as the experimental samples to suffer from explosion blasts with different peak air overpressures(167 kPa~482 kPa)and varying number of repeated blasts.The cumulative effect of craniocerebral trauma was most pronounced for moderate repeated blast,showing approximately 95%increase of trauma severity with penta blast,and an approximately 85%increase of trauma severity with penta minor blast.The cumulative effect of craniocerebral trauma from severe,repeated blast has a smaller rate of change compared to the other two conditions.The severity of trauma from penta blast increased by approximately 69%compared to a single blast.Comprehensive physiological,pathological and biochemical analysis show that the degree of neurological trauma caused by repeated blasts is higher than that of single blasts,and the pathological trauma to brain tissue is more extensive and severe.The trauma degree remains unchanged after double blast,increases by one grade after triple or quadruple blast,and increases by two grades after penta blast.

Development of a novel critical nitrogen concentration-cumulative transpiration curve for optimizing nitrogen management under varying irrigation conditions in winter wheat

Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop water status.With three-year field experiments with winter wheat,encompassing two irrigation levels(rainfed and irrigation at jointing and anthesis)and three N levels(0,180,and 270 kg ha1),this study aims to establish a novel approach for determining the Nc dilution curve based on crop cumulative transpiration(T),providing a comprehensive analysis of the interaction between N and water availability.The Nc curves derived from both crop dry matter(DM)and T demonstrated N concentration dilution under different conditions with different parameters.The equation Nc=6.43T0.24 established a consistent relationship across varying irrigation regimes.Independent test results indicated that the nitrogen nutrition index(NNI),calculated from this curve,effectively identifies and quantifies the two sources of N deficiency:insufficient N supply in the soil and insufficient soil water concentration leading to decreased N availability for root absorption.Additionally,the NNI calculated from the Nc-DM and Nc-T curves exhibited a strong negative correlation with accumulated N deficit(Nand)and a positive correlation with relative grain yield(RGY).The NNI derived from the Nc-T curve outperformed the NNI derived from the Nc-DM curve concerning its relationship with Nand and RGY,as indicated by larger R2 values and smaller AIC.The novel Nc curve based on T serves as an effective diagnostic tool for assessing winter wheat N status,predicting grain yield,and optimizing N fertilizer management across varying irrigation conditions.These findings would provide new insights and methods to improve the simulations of water-N interaction relationship in crop growth models.

Cumulative Air Quality Impacts from Twenty-Two Major Power Plants

Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developments at risk.This study assessed the cumulative impacts of air emissions from 22 major power plants in southeast Bangladesh planned to generate 21,550 MW of electricity.It also includes anticipated growth in small to medium size industries,brickfields,highway traffic,inland water transport,transhippers,jetty,and vessel transports used for transporting fuel resources for these power plants.A 50 km by 50 km airshed is considered for air quality modeling.Cumulative analysis indicates that predicted MGLCs(Maximum Ground Level Concentrations)of NO2 and CO are complying with both Bangladesh NAAQS(National Ambient Air Quality Standards)and WBG(World Bank Group)Guidelines.The daily average MGLC of PM_(2.5)(62.45µg/m^(3))from all sources complies with NAAQS,however,exceeds the WBG Guidelines.Annual PM_(2.5) concentration(15.45µg/m^(3))exceeds NAAQS and WBG Guidelines.The PM10 concentration complies with the NAAQS for both 24-hour and annual averaging times.Annual average concentration(23.12µg/m^(3))exceeds WBG Guidelines.Daily average SO2 concentration(102.49µg/m^(3))complies with the NAAQS however,it exceeds the WBG guideline values.High concentrations of PM_(2.5) and SO2 are due to the contribution of transboundary emissions and secondary pollutants in the atmosphere.This dispersion modeling outcome can be used by the policymakers for the pollution reduction strategy.

Rational screening of metal coating on Zn anode for ultrahigh-cumulative-capacity aqueous zinc metal batteries

Aqueous zinc metal batteries feature intrinsic safety,but suffer from severe dendrite growth and water-derived side reactions.Many metal coatings have been explored for stabilizing Zn metal anode via a trialand-error approach.Here,we propose an exercisable way to screen the potential metal coating on Zn anodes in view of de-polarization effect and dendrite-suppressing ability theoretically.As an output of this screening,cadmium(Cd) metal is checked experimentally.Therefore,symmetric ZnllZn cells using Cd coated Zn(Zn@Cd) exhibit an ultra-long cycle life of 3500 h(nearly 5 months) at a high current density of 10 mA cm^(-2),achieving a record-high cumulative capacity(35 A h cm^(-2)) compared to the previous reports.The full cells of Zn@Cd‖MnO_(2) display a markedly improved cycling performance under harsh conditions including a limited Zn supply(N/P ratio=1.7) and a high areal capacity(3.5 mA h cm^(-2)).The significance of this work lies in not only the first report of Cd coating for stabilizing Zn metal anode,but also a feasible way to screen the promising metal materials for other metal anodes.

Association ofβ-lactam antimicrobial's exposure with carbapenem-resistant Pseudomonas aeruginosa infection:a cumulative meta-analysis

Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of inappropriate exposure to different antimicrobials in resistant Pseudomonas aeruginosa infection could help in elucidating the effective approach towards using antimicrobials in vulnerable patients with CRPA infection.Object:To investigate the association between exposure ofβ-lactam antimicrobials and CRPA infection relative to control patients.Methods:The MEDLINE/PubMed and OVID/Embase databases were used to search case-control and cohort studies in English language which reported antimicrobial exposure as risk factors for CRPA infection.The pooled odds ratios(OR)were calculated using a random-effect and fixed-effect model,and forest plots from a cumulative meta-analysis method were used to better show how pooled OR changed as updated evidence accumulated.Results:A total of 24 studies comprising 7039 participants were included for cumulative meta-analysis.A positive correlation was found between development of CRPA infection and exposure of beta-lactam antimicrobials:carbapenems(OR=7.60,95%CI:3.95 to 14.62,P<0.0001),imipenem(OR=9.81,95%CI:5.56 to 17.33),ampicillin(OR=1.86,95%CI:1.14 to 2.41),piperacillin(OR=2.82,95%CI:1.46 to 2.43),penicillins(OR=1.42,95%CI:0.90 to 2.24),cephalosporins(OR=1.88,95%CI:1.46 to 2.43)andβlactamase inhibitors(OR=1.96,95%CI:1.44 to 2.67).Further,exposure of other antimicrobial agents like quinolone(OR=2.35,95%CI:1.78 to 3.10),ciprofloxacin(OR=2.35,95%CI:1.66 to 3.95),aminoglycoside(OR=2.17,95%CI:1.60 to 2.95),amikacin(OR=3.11,95%CI:2.10 to 4.61),glycopeptides(OR=3.02,95%CI:1.92 to 4.75)and vancomycin(OR=3.26,95%CI:1.48 to 7.18),were also found to be positively associated with development of CRPA infection.Conclusions:Exposure of all kinds ofβ-lactams is significantly associated with development of carbapenemresistant Pseudomonas aeruginosa infection.These findings provide an impetus to take a more active approach while usingβ-lactam antimicrobials in patients with resistant Pseudomonas aeruginosa infections.

Needs and Challenges of Nigeria Petroleum Industry in Assessing Process Safety Cumulative Risk

A cross-sectional exploratory assessment of the needs and challenges of petroleum industry in Nigeria, in assessing process safety cumulative risk for major accidents prevention was investigated. A purposive cum random sampling technique was used in this study, among selected petroleum companies operating in Nigeria. Survey questionnaires were received from 216 participants made up of asset integrity engineers/operators, process safety experts, production safety professionals in the petroleum industry in Nigeria. Data analyses were carried out to cover descriptive and inferential statistics. Overall, the study recognized that assessing process safety cumulative risk is not a simple process due largely to the changing nature of safety critical barriers degradation data. The study result showed four main challenges faced by petroleum industries in Nigeria, in assessing process safety cumulative risk: 1) the study showed that 94% of the respondents agreed that there is limited accessibility to safety critical barriers degradation data (little automation). Also 2) 94% of the respondents accounted for poor knowledge of process safety cumulative risk is and agreed it to be of low rating. The result further showed that 3) 90% of the respondents demonstrated that there are no guidance and procedures in assessing process safety cumulative risk and finally 4) 92% of the respondents reported that there is no real-time risk visualization model/ tool. Addressing these issues and challenges by the petroleum industries in the study area, will lead to successful assessment of process safety cumulative risk, thereby reducing the risk of major accidents.

Shaking table test and cumulative deformation evaluation analysis of a tunnel across the hauling sliding surface

To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas.

Non-Gaussianity detection of single-mode rotationally symmetric quantum states via cumulant method

The non-Gaussianity of quantum states incarnates an important resource for improving the performance of continuous-variable quantum information protocols.We propose a novel criterion of non-Gaussianity for single-mode rotationally symmetric quantum states via the squared Frobenius norm of higher-order cumulant matrix for the quadrature distribution function.As an application,we study the non-Gaussianities of three classes of single-mode symmetric non-Gaussian states:a mixture of vacuum and Fock states,single-photon added thermal states,and even/odd Schr¨odinger cat states.It is shown that such a criterion is faithful and effective for revealing non-Gaussianity.We further extend this criterion to two cases of symmetric multi-mode non-Gaussian states and non-symmetric single-mode non-Gaussian states.

Feasibility of Integrating Leprosy Post-Exposure Prophylaxis with Single-Dose Rifampicin (LPEP) into Routine Leprosy Control Program in Bukedi and Teso Regions in Uganda

Background: World Health Organization recommends the implementation of contact tracing and Leprosy Post Exposure prophylaxis (LPEP) to interrupt the chain of transmission. To accelerate the uptake of this recommendation, a cross-sectional study among contacts of leprosy patients was conducted to investigate the feasibility of integrating leprosy systematic contact tracing and post-exposure prophylaxis (PEP) into the routine leprosy control program. Methods: This was a mixed methods cross-sectional study. The study was implemented in Kumi, Ngora, Serere, Soroti, Budaka and Kibuku Districts. Results: The 45 enrolled index patients (97.8% of the registered) identified a total of 135 contacts, of which 134 (99·2%) consented and were screened. Among them, one new leprosy patient was identified and started on treatment with multidrug therapy (MDT). All the eligible contacts, received the prophylactic treatment with Single Dose Rifampicin (SDR). Overall, SDR was administered to 133(98.5% of the listed contacts) with no adverse event reported. Factors associated with successful contact investigation and management included: Involvement of index patients, health care workers during the contact screening and SDR A administration, counselling of the index patients and contacts by the health care works, LPEP being administered as Directly observed Therapy (DOT) among others. Results Interpretation: The integration of leprosy post-exposure prophylaxis with administration of SDR and contact tracing is feasible, generally accepted by the patient, their contacts and health workers and can be integrated into the National Leprosy control programmes with minimal additional efforts once contact tracing has been established. Therefore, we recommend integration of administration of SDR in to the routine leprosy control program.

The lithology and composition of lunar mantle modified by ilmenite bearing cumulate:A thermodynamic model

Due to their high density,the ilmenite-bearing cumulates(IBC)(with or without KREEP)formed during the late-stage lunar magma ocean solidification are thought to sink into the underlying lunar mantle and trigger lunar mantle overturn.Geophysical evidence implied that IBC may descend deep inside the Moon and remain as a partially molten layer at the core-mantle boundary(CMB).However,partial melting may have occurred on the mixed mantle cumulates during the sinking of IBC/KREEP and the silicate melt may be positively buoyant,thus preventing the IBC/KREEP layer from sinking to the CMB.Here,we perform thermodynamic simulation on the stability of lunar mantle cumulates at different depths mixed with different amounts of IBC/KREEP from an updated LMO model.The modeling results suggest that the sinking of IBC/KREEP will cause at least 5 wt%partial melting in the shallow(~120 km)and a much larger degree of partial melting in the deep lunar mantle(~420 km).Due to the density contrast with the surrounding mantle,IBC/KREEP-bearing melts could potentially decouple under certain conditions.The modified lunar mantle by sinking of IBC/KREEP can better explain the formation of different kinds of lunar basaltic magma than the primary lunar mantle formed through differentiation of lunar magma ocean.Sinking of IBC/KREEP back into the lunar mantle may introduce plagioclase,clinopyroxene,garnet,and incompatible radioactive elements into the deep lunar mantle,which will further affect the thermal and chemical evolution of the lunar interior.

Accurate models and nutritional strategies for specific oxidative stress factors: Does the dose matter in swine production?

Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.

Helicobacter pylori:High dose amoxicillin does not improve primary or secondary eradication rates in an Irish cohort

BACKGROUND Helicobacter pylori(H.pylori)eradication rates have fallen globally,likely in large part due to increasing antibiotic resistance to traditional therapy.In areas of high clarithromycin and metronidazole resistance such as ours,Maastricht VI guidelines suggest high dose amoxicillin dual therapy(HDADT)can be considered,subject to evidence for local efficacy.In this study we assess efficacy of HDADT therapy for H.pylori eradication in an Irish cohort.AIM To assess the efficacy of HDADT therapy for H.pylori eradication in an Irish cohort as both first line,and subsequent therapy for patients diagnosed with H.pylori.METHODS All patients testing positive for H.pylori in a tertiary centre were treated prospectively with HDADT(amoxicillin 1 g tid and esomeprazole 40 mg bid×14 d)over a period of 8 months.Eradication was confirmed with Urea Breath Test at least 4 wk after cessation of therapy.A delta-over-baseline>4%was considered positive.Patient demographics and treatment outcomes were recorded,analysed and controlled for basic demographics and prior H.pylori treatment.RESULTS One hundred and ninety-eight patients were identified with H.pylori infection,10 patients were excluded due to penicillin allergy and 38 patients refused follow up testing.In all 139 were included in the analysis,55%(n=76)were female,mean age was 46.6 years.Overall,93(67%)of patients were treatment-naïve and 46(33%)had received at least one previous course of treatment.The groups were statistically similar.Self-reported compliance with HDADT was 97%,mild side-effects occurred in 7%.There were no serious adverse drug reactions.Overall the eradication rate for our cohort was 56%(78/139).Eradication rates were worse for those with previous treatment[43%(20/46)vs 62%(58/93),P=0.0458,odds ratio=2.15].Age and Gender had no effect on eradication status.CONCLUSION Overall eradication rates with HDADT were disappointing.Despite being a simple and possibly better tolerated regime,these results do not support its routine use in a high dual resistance country.Further investigation of other regimens to achieve the>90%eradication target is needed.

The Evaluation of Alternative Risk Control Schemes Based on Cumulative Prospect Theory

Based on the analysis of the evaluation problems associated with the risk control scheme for major engineering projects,the evaluation method of the risk control scheme considering the irrational behavior of evaluation members in fuzzy random environment is proposed.Firstly,a maximum entropy model corresponding to any evaluation member is es-tablished by using triangular fuzzy random variables and grey correlation coefficient in order to obtain the weight of each risk factor of the member.Secondly,a nonlinear programming model is established according to the principle of minimiz-ing deviation to estimate the weight of different evaluation members on the evaluation of alternative risk control schemes.Lastly,the cumulative entropy model is used to calculate the weight of risk control schemes.Cumulative prospect theory obtains the comprehensive prospect utility value of each alternative to determine the optimal alternative.

Cardiac Safety with High Cumulative Dose of Pegylated Liposomal Doxorubicin in Patients with Metastatic Breast Cancer Previously Treated with Conventional Anthracyclines

Introduction: The treatment of metastatic breast cancer (MBC) is still challenging. Many studies documented the efficacy of pegylated liposomal doxorubicin (PLD) in patients with MBC, but there is a limited data about the cardiac safety with high cumulative dose (HCD) of PLD. Aim of the work: We conducted this trial to outline the cardiac safety of HCD of PLD in patients with MBC who previously received conventional anthracyclines. Methods: During the period of nine years (January 2011 to December 2019). We extracted the data of the patients with MBC receiving PLD at Medical Oncology Department, South Egypt Cancer Institute, Assiut University. These included patients’ demographics and therapeutic data including the full data of PLD, prior conventional anthracyclines, prior trastuzumab, and prior radiotherapy. Also, data about comorbidities as well as cardiac and other toxicities of PLD were obtained. The data was analysed using SPSS v. 21. Results: For all 81 eligible patients, the mean age was 43.9 years (±standard deviation (SD) 13.2). The mean cumulative dose of PLD was 378.4 mg/m2 (± SD of 250.2) and a range of 100 - 1200 mg/m2. About thirty-one (38.3%) patients received high cumulative dose (400 mg/m2 or more), while the remaining 50 patients did not. The decline in left ventricular ejection fraction (LVEF) was relatively rare;and of low grade. Grade 2 decline in LVEF occurred in only two patients who received high cumulative dose of PLD, and only one patient who did not reach HCD (p = 0.555). Grade 3 or 4 decline in LVEF did not occur in patients either with or without HCD. Regarding other toxicities, there was a significant increase in incidence of all grades palmar plantar erythrodysesthesia (PPE) in patients who received HCD of PLD when compared to those who did not reach the HCD (38.7% versus 16% respectively;p = 0.021). Conclusion: Our study concluded that the use of PLD seems to be a justified agent in the treatment of MBC who previously treated by conventional anthracyclines in the adjuvant, metastatic or both settings, even in patients reaching the cumulative dose of conventional anthracycline.

Determination of Timer Error and Evaluation of Its Effect on Dose for OB6, GammaBeam X200 and X-Ray Irradiators at the Secondary Standard Dosimetry Laboratory in Nigeria

Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.

A Bioequivalence Study of Empagliflozin/Metformin Fixed-Dose Combination in Healthy Subjects under Fasting Conditions

Background: This study evaluated the bioequivalence of empagliflozin 12.5 mg/metformin 1000 mg tablets compared to Synjardy® (Empagliflozin 12.5 mg/metformin 1000 mg) tablets in healthy male subjects under fasting conditions. Methods: This was a phase I, randomized, single-dose, two-period, two-sequence, crossover study to evaluate the bioequivalence (BE) profiles of two fixed-dose combinations (FDCs) of empagliflozin/metformin. Cmax, AUC0-t and AUC0-∞ from test and reference formulations were evaluated to access BE. The plasma concentrations were measured using a validated liquid chromatography-mass spectrometry (LC-MS/MS) method. Of the 24 subjects enrolled, 23 completed both periods of the study. The two formulations test and reference were considered bioequivalent if 90% confidence interval (CI) fell within 80.00% - 125.00% for Cmax, AUC0-t and AUC0-∞. Tolerability and safety were assessed throughout the study. Results: The pharmacokinetic (PK) parameters were similar between the test product (T) and reference product (R) Synjardy®. The 90% CI of the test/reference ratios of log-transformed PK parameters point estimates was Cmax: 89.87% (85.68% - 94.27%), AUC0-t: 87.91% (83.65% - 92.39%) and AUC0-∞: 87.16% (82.80% - 91.75%) to empagliflozin and Cmax: 92.19% (87.95% - 96.65%), AUC0-t: 91.38% (84.42% - 98.91%) and AUC0-∞: 93.78% (83.82% - 104.93%) to metformin respectively (90% CI for all PK parameters fell within 80.00% - 125.00%). Conclusion: Our results demonstrated BE between the test and reference formulations of oral tablets of empagliflozin 12.5 mg/metformin 1000 mg (FDC) in healthy male subjects under fasting conditions.

Validation of the TOPAS Monte-Carlo Code of the Off-Field Dose of a 6 MV Synergy Linac

The risk of radiation-induced second cancer and the late tissue loss due to Off-field doses in radiotherapy remain a serious concern. Monte Carlo (MC) simulation is currently one of the most accurate methods for calculating these doses. MC simulation model based on the Particle Simulation Tool (TOPAS) has been developed to simulate the off-field dose of an Elekta Synergy linear accelerator (Linac) emitting 6 MV photons. Measurements were taken in a water phantom using an ionization chamber to validate this model. The Percentage Depth Dose (PDD) at the depth of 0.0, 5.0, 10.0 and 15.0 cm from the beam axis for a 10 × 10 cm2 field size was measured and simulated. Off-field dose profiles at the depth of 1.5 (dmax), 5.0 and 10.0 cm for field sizes of 5 × 5, 10 × 10, 15 × 15, and 20 × 20 cm2 respectively were measured and simulated. Comparison of measured and simulated off-field dose values showed a good agreement. The average gamma passing rate of the PDDs and profiles curves for off-field doses were 87.5% and 98.11% respectively. The local dose difference based on the PDD curve between the measured and simulated was less than 6.0 % for all locations. For all field size considered in this study, the average difference between profile curves for off-field dose measured and simulated was 9.1%. PDDs and Profiles curves for off-field dose simulation uncertainties were less than 2.0% and 1.0% respectively. TOPAS-MC simulation model developed is a good representation of our 6 MV Linac Elekta Synergy for assessing off-field dose, which would be the primary cause of some secondary cancers.

Life Time Attributable Cancer Risk Estimated Using Scanner Reported Dose Length Product during Chest Computed Tomography Imaging in Young Children

This study aims to estimate the lifetime attributable cancer risk (LAR) for pediatric chest computed tomography (CT) examinations in five age groups using recently published age and region-specific conversion coefficients multiplying the widely available scanner registered dose length products (DLP) displayed on the CT console and hence calculating the Effective Dose (ED). The ED is then multiplied by the International Commission on Radiological Protection (ICRP) published risk factor for LAR. The obtained LAR values are compared with the international literature. Factors that may affect the LAR value are reported and discussed. The study included one hundred twenty five chest CT examinations for both males and females aged from less than one year to fifteen years. The patients reported data are from one single medical institution and using two CT scanners from June 2022 to December 2023. The results of this study may serve as benchmark for institutional radiation dose reference levels and risk estimation.