Concentration Variance Research Articles

Impacts of ENSO on Tropical Pacific Chlorophyll Biomass Under Historical and RCP8.5 Scenarios

AbstractThe present study aims to investigate the influences of El Niño and Southern Oscillation (ENSO) events on chlorophyll biomass in the tropical Pacific under historical and RCP8.5 scenarios with simulations from the Community Earth System Model Large Ensemble (CESM‐LE) project. Large variance in surface chlorophyll concentrations is identified across the Peruvian Upwelling (PU), Equatorial Upwelling (EU), and Western Pacific (WP) regions within the tropical Pacific. Results suggest that responses of surface chlorophyll to ENSO in these regions are governed by different mechanisms. The increasing chlorophyll during La Niña is a consequence of increasing nutrients, influenced by local upwelling systems in the PU and EU regions, while the supplementary nutrients in the WP region arise from the eastern Pacific through stronger surface westward currents. Under RCP8.5 scenario, stronger water warming in the eastern equatorial Pacific leads to a remarkable reduction in the amplitudes of seasonal cycles and interannual variations of chlorophyll in both PU and EU regions. This results in less responsiveness of the chlorophyll biomass to El Niño and moderate La Niña compared to the historical period. However, though warming induces a decrease in chlorophyll concentrations in the WP region, the interannual variations of chlorophyll have shown an improvement in correlation with ENSO events. Meanwhile, despite the small phytoplankton‐dominated community being observed under future scenario, species dominance is likely to shift back to diatoms once extreme La Niña occurs, which is unseen in all El Niño and moderate La Niña cases.

Race explains substantial variance in whole blood thiamine diphosphate concentrations

Deficiency for thiamine (vitamin B1), traditionally assessed via the activity of the thiamine-dependent enzyme erythrocyte transketolase, has been reported in individuals with alcohol use disorder (AUD) and in people with HIV; concentrations of the metabolically active diphosphate form, however, have yet to be reported in HIV cohorts and results in AUD are equivocal. In this cross-sectional study, samples from 170 AUD, 130 HIV, and 100 healthy control individuals were analyzed to test the hypothesis that AUD and HIV groups relative to healthy controls would show low whole blood thiamine diphosphate (TDP) concentrations related to peripheral neuropathy. TDP concentrations were not different in the 3 study groups (P = .6141) but were lower in Black (n = 172) relative to White (n = 155) individuals (P < .0001) regardless of group. In a multiple regression, race relative to diagnoses explained more than 10 times the variance in whole blood TDP concentrations (F4,395 = 3.5, P = .0086; r2 = 15.1]. Performance on a measure of peripheral neuropathy (2-point discrimination) was worse in the HIV and AUD cohorts relative to the healthy control group (P < .0001) but was not associated with TDP concentrations. These findings suggest that Black individuals carry a heightened vulnerability for low whole blood TDP concentrations, but the clinical significance and mechanisms underlying these results remain to be determined.

Job function as determinant of clinker exposure at workplaces during cement production.

In the cement production industry, exposure to airborne particulate matter is associated with a decline in lung function and increased airway symptoms. Exposure to clinker-the major constituent of cement and supposedly the cause of the observed adverse health effects-was determined recently in 15 cement production plants located in 8 different countries (Estonia, Greece, Italy, Norway, Sweden, Switzerland, Spain, Turkey). It was shown that the median clinker abundance in the thoracic fraction varied between approximately 20% and 70% for individual plants. The present study complements the previous work by investigating the significance of job function as a determinant of clinker exposure. The elemental composition (water and acid-soluble fractions separately) of 1,227 personal thoracic workplace samples was analyzed by positive matrix factorization (PMF) to determine the contribution of different sources to the composition of airborne particulate matter and to quantify the clinker content. Median thoracic mass air concentrations varied for individual job functions between 0.094 and 12 mg/m3 (estimated separately for different plants). The PMF 5-factor solution yielded median relative clinker abundances in the personal thoracic samples between 7.6% and 81% for individual job functions. Thoracic clinker air concentrations are highest for cleaning, production, and maintenance work, and lowest for administration and other work. Foremen and laboratory personnel show intermediate exposure levels. The plant was found to have a much higher contribution to the total variance of the thoracic clinker air concentrations than the job function. Thoracic clinker air concentrations (medians between 0.01 and 5.5 mg/m3) are strongly correlated with the thoracic mass air concentrations and to a lesser extent with the relative clinker abundance in an aerosol sample. Job function is an important predictor of exposure to clinker in the cement production industry. As clinker is suspected to be the causal agent for the observed adverse health effects among cement production workers, the clinker air concentration may be a better exposure metric than thoracic air mass concentration despite the strong correlation between the two. Reduction strategies should focus on the most exposed job categories cleaning, production, and maintenance work.

An approach to understand the uranium’s concentration variance on the eastern and western sides of the Nile Valley phosphorites, Egypt

The Nile Valley is a main area for Egyptian phosphorites. The studied samples from the eastern and western sides of the Nile Valley showed similarities in their characteristics, suggesting one depositional basin, but they varied in their uranium content, with averages recorded at 91.7 and 44.83 ppm on the eastern and western sides, respectively. The evidence pointed out that initially the uranium was formed by adsorption onto the iron oxides and organic matter surfaces, then it was partially removed under the effect of groundwater, and the removal was deeper in the western phosphorites than the eastern ones.

Distribution and risk assessment of microplastic pollution in a rural river system near a wastewater treatment plant, hydro-dam, and river confluence

Rivers are the natural drainage system, transporting anthropogenic wastes and pollution, including microplastics (plastic < 5 mm). In a riverine system, microplastics can enter from different sources, and have spatial variance in concentration, physical and chemical properties, and imposed risk to the ecosystem. This pilot study presents an examination of microplastics in water and sediment samples using a single sample collection from the rural Raquette River, NY to evaluate a hypothesis that distinct locations of the river, such as downstream of a wastewater treatment plant, upstream of a hydro-dam, and river confluence, may be locations of higher microplastics concentration. In general, our results revealed the presence of high microplastic concentrations downstream of the wastewater treatment plant (in sediments), upstream of the hydro dam (both water and sediment), and in the river confluence (water sample), compared to other study sites. Moreover, the risk assessment indicates that even in a rural river with most of its drainage basin comprising forested and agricultural land, water, and sediment samples at all three locations are polluted with microplastics (pollution load index, PLI > 1; PLIzone = 1.87 and 1.68 for water and sediment samples respectively), with risk categories between Levels I and IV (“minor” to “danger”). Overall, the river stands in a “considerable” risk category (PRIzone = 134 and 113 for water and sediment samples respectively). The overall objective of this pilot study was to evaluate our hypothesis and advance our understanding of microplastic dynamics in rural river systems, elucidating their introduction from a point source (wastewater treatment plant), transit through an impediment (hydro-dam), and release into a vital transboundary river (confluence of Raquette-St. Lawrence Rivers).

Identification of exhaust stack sampling location of a research reactor considering ANSI/HPS N13.1-2011 mixing criteria using computational fluid dynamics

ABSTRACT Research Reactors have exhaust stacks that emit filtered radioactive gaseous waste into the atmosphere. In this research work, to check whether the radioactive gaseous waste met the requirements of ANSI/HPS N13.1–2011 mixing criteria, computational fluid dynamics (CFD) analysis was performed. According to ANSI criteria, Coefficient of Variance (COV) of velocity uniformity, flow angle, tracer gas, and aerosol particles concentration should be less than 20%. Therefore, the COV of the four parameters at different sampling positions along the stack height, with eight tracer gas and eight particles injection cases, were analyzed. The COV of velocity at 6 m height is 17.5% and flow cyclone is 9.8 degree. The results indicated that the 6 m height of the stack is enough for cyclone angle and COV of velocity to fulfill the ANSI mixing criteria. The COV of tracer gas concentration in one to eight injection cases is 10%, 4.8%, 7.5%, 17%, 2.5%, 6%, 13%, and 5% at 14 m stack height so the tracer gas also satisfied the standard mixing criteria in a concise length of 14 m because of the minimal difference in densities of tracer gas and air. However, due to their much higher density, aerosol particles took much longer to mix into the air. At 60 m stack height, the COV of aerosol particle concentration in one to eight injection cases is 14.8%, 18%, 8%, 12%, 11%, 15%, 15.5%, and 2%, respectively. As a result, when the stack height is set to 60 m, the COV of velocity, cyclone flow angle, tracer gas concentration, and aerosol particle concentration are found to meet the ANSI mixing criteria. Therefore, the minimum recommended height of the stack is proposed to be 60 m for the case under consideration.

Synthesis and characterization of PEG/CS‐AgNO3 polymer nanocomposites for flexible optoelectronic and energy storage applications

AbstractThe Polyethylene glycol (PEG) and Chitosan (CS)/silver nitrate (AgNO3) thin films were prepared by utilizing the casting technique to enhance their optical, dielectric, and electrical properties. Their physicochemical characteristics were investigated using a variety of techniques. The FT‐IR study demonstrates that the addition of AgNO3 NPs results in a discernible difference in the intensities and locations of vibrational peaks of all bands, supporting the incorporation of AgNO3NPs inside the PEG/CS. The XRD analysis indicates that the peak at 2θ = 23.1° broadens and strengthens proportionally with the increase of AgNO3 NPs. This observation suggests that the incorporation of AgNO3 NPs into PEG/CS results in a greater degree of amorphous characteristics compared to the PEG/CS blend. Additionally, when the amount of AgNO3 NPs increases in the PEG/CS, the energy band gap decreases, resulting in the creation of localized states between the valence and conduction bands. These polymer nanocomposite films' electrical conductivity, dielectric constant, and dielectric loss all increased with frequency increased and showed variance for various composite concentrations. These AgNO3NPs/PEG/CS films can be promising options for frequency‐tunable nanodielectrics, flexible dielectric substrates, and bandgap‐regulated materials for upcoming microelectronic, capacitive energy storage, and optoelectronic technologies, according to the experimental results.Highlights AgNO3NPs/PEG/CS nanocomposites films were obtained. The optical properties of the prepared films were calculated. Optical energy‐gap for prepared samples was reduced after adding AgNO3NPs. The dielectric properties of the AgNO3NPs/PEG/CS films are improved. AgNO3NPs/PEG/CS films were suggested to be used in energy storage devices.

Experimental investigation of scalar dispersion in indoor spaces

The scalar dispersion from point sources in indoor spaces is experimentally investigated using simultaneous particle–image velocimetry and planar laser-induced fluorescence techniques in a 20:1 and a 60:1 full-to-model scale room model. The ventilation inlets dominate turbulence production, with magnitudes of the velocities and Reynolds stresses observed to increase with air changes per hour (ACH). Mean concentration maps show a dependence on the ACH and source location which is attributed to the flow field at the near-source region. The peak-to-mean concentration shows a weak dependence on the mean concentration and concentration variance maps, indicating risk for toxic chemicals may be underpredicted if based only on these information. The concentration PDFs are generally well-described by exponential distributions with C99/crms′ values never exceeding 5.0. The magnitudes of the advective and turbulent scalar fluxes are strongly dependent on the ACH and source location, neither of which are able to dominate the other by more than an order of magnitude. The eddy diffusivity tensor was measured and a conditional-averaging based method is proposed to approximate it to an isotropic eddy diffusion coefficient, K. For real applications where K is used to estimate magnitudes of the turbulent scalar flux using the gradient transport model, the assumption of isotropic turbulence can introduce an uncertainty of around 17.8%.

Evaluation of atmospheric methane concentrations and growth trends in selected locations of Rivers State, Nigeria

The study addresses the increasing atmospheric methane mixing ratios in Rivers State, Nigeria, a pressing issue linked to global warming. The objective was to analyze the growth rate and sources of methane emissions in the region. Using a quantitative approach, ground-level methane measurements were collected from seven different locations between September 2021 and June 2022, complemented by data from the Tropospheric Monitoring Instrument satellite spanning January 2019 to June 2022. The methodology combined descriptive, comparative, and regression analyses with plume chemistry modeling using the U.S. EPA Atmospheric Dispersion Modeling System software. Results indicated significant spatial variance in methane concentrations, ranging from 9.76 ppm in Ogbogu to 21.5 ppm in Choba, with notable temporal fluctuations. Regression analysis revealed a correlation between atmospheric conditions and methane levels, while plume chemistry identified a landfill near Choba market as a major emission source, raising concerns about tropospheric ozone pollution and health risks. The study highlights the need for effective waste management in Rivers State and emphasizes the importance of continuous monitoring to address the challenges posed by methane emissions and tropospheric ozone pollution.

Tranexamic Acid in Hip Reconstructions in Children with Cerebral Palsy: A Double-Blind Randomized Controlled Clinical Trial.

Surgical treatment is indicated for hip dislocation in patients with cerebral palsy (CP), but it requires care due to the state of nutrition and associated clinical comorbidities. The use of resources that minimize blood loss and the need for blood transfusions are essential to avoid complications. Tranexamic acid (TXA) has been highlighted for orthopedic surgeries to control intraoperative bleeding; however, there is a lack of large studies for its use in hip surgeries in patients with CP. This study aims to evaluate the efficacy and safety of tranexamic acid to reduce bleeding in pediatric patients with cerebral palsy undergoing surgical treatment for hip instability. A sample of 31 patients with CP who underwent surgical treatment for hip dislocation (hip adductor stretching, varization osteotomy of the proximal femur and acetabuloplasty using the Dega technique) was randomly divided into groups: control (n = 10) and TXA (n = 21). Preoperative and 24 h hemoglobin concentrations, the length of hospital stay (LHS), and intraoperative bleeding (IB) were analyzed. TXA significantly reduced the IB (p = 0.02). The variance in hemoglobin concentration was lower for the TXA group, but without statistical significance (p = 0.06). There was no difference in LHS. Also, no statistical difference was observed for the number of transfusions (p = 0.08). The findings provide evidence of the effectiveness of TXA in decreasing intraoperative bleeding and its safety for use in pediatric patients with cerebral palsy.

Large spread in interannual variance of atmospheric CO2 concentration across CMIP6 Earth System Models

Numerical Earth System Models (ESMs) are our best tool to predict the evolution of atmospheric CO2 concentration and its effect on Global temperature. However, large uncertainties exist among ESMs in the variance of the year-to-year changes of atmospheric CO2 concentration. This prevents us from precisely understanding its past evolution and from accurately estimating its future evolution. Here we analyze various ESMs simulations from the 6th Coupled Model Intercomparison Projects (CMIP6) to understand the origins of the inter-model uncertainty in the interannual variability of the atmospheric CO2 concentration. Considering the observed period 1986-2013, we show that most of this uncertainty is coming from the simulation of the land CO2 flux internal variability. Although models agree that those variations are driven by El Niño Southern Oscillation (ENSO), similar ENSO-related surface temperature and precipitation teleconnections across models drive different land CO2 fluxes, pointing to the land vegetation models as the dominant source of the inter-model uncertainty.

A Single-Step Genome-Wide Association Study for Semen Traits of Egyptian Buffalo Bulls.

The present study aimed to contribute to the limited research on buffalo (Bubalus bubalis) semen traits by incorporating genomic data. A total of 8465 ejaculates were collected. The genotyping procedure was conducted using the Axiom® Buffalo Genotyping 90 K array designed by the Affymetrix Expert Design Program. After conducting a quality assessment, we utilized 67,282 SNPs genotyped in 192 animals. We identified several genomic loci explaining high genetic variance by employing single-step genomic evaluation. The aforementioned regions were located on buffalo chromosomes no. 3, 4, 6, 7, 14, 16, 20, 22, and the X-chromosome. The X-chromosome exhibited substantial influence, accounting for 4.18, 4.59, 5.16, 5.19, and 4.31% of the genomic variance for ejaculate volume, mass motility, livability, abnormality, and concentration, respectively. In the examined genomic regions, we identified five novel candidate genes linked to male fertility and spermatogenesis, four in the X-chromosome and one in chromosome no. 16. Additional extensive research with larger sample sizes and datasets is imperative to validate these findings and evaluate their applicability for genomic selection.

Predictors of blood ionized calcium concentration in sick adult cattle.

Data on the factors affecting blood ionized calcium concentration (ciCa2+ ) and diagnostic performance of serum total calcium concentration (ctCa) measurements to detect abnormal blood iCa2+ status are lacking in sick adult cattle. Assess the association of ciCa2+ with venous blood pH, plasma concentrations of chloride (cCl), sodium (cNa), and potassium (cK), and ctCa, and total protein, albumin, and globulin concentrations in sick adult cattle. Two-hundred and sixty-five adult cattle (≥1-year-old) with different diseases. Prospective study. Whole blood pH, ciCa2+ , cNa, cK, and cCl were measured using a blood gas and electrolyte analyzer, whereas ctCa, and total protein, and albumin concentrations were determined using an autoanalyzer. The relationship between ciCa2+ and venous blood pH, plasma cCl, cNa, cK, and ctCa, and total protein, albumin, and globulin concentrations was investigated. Sensitivity and specificity were calculated for ctCa for diagnosis of abnormal ciCa2+ . Sensitivity of ctCa measurements to detect abnormal ciCa2+ was 66.0% whereas specificity of ctCa measurements was 72.3%. Serum total calcium concentration measurements accounted for 42% of adjusted blood ionized calcium (iCa2+ 7.40 ) concentration variance. Plasma cCl, and cK had explanatory power of ciCa2+ 7.40 , accounting for an additional 21% and 9% of the variance, respectively. Serum tCa measurements failed to accurately predict blood iCa2+ status in ill adult cattle. Serum tCa concentrations and plasma cCl were the strongest predictors of ciCa2+ in sick adult cattle.

Comparison of the effects of calcium ammonium nitrate and stabilized urea fertilizers on grass and silage yields and quality

AbstractEffects of Calcium Ammonium Nitrate (CAN) and Stabilized Urea (SU) fertilizers were compared for herbage yield and composition and silage composition of perennial ryegrass (Lolium perenne L.) swards over a two‐year study. The aim of this experiment was to establish the likely impacts of farmers transitioning to using SU fertilizers in order to reduce the nitrogenous emissions associated with silage production as the agriculture industry moves to address the challenges of climate change. Experimental plots of 7.5 m2 area were established in a randomized block experiment comprising 4 replicates of 18 treatments in a 3 × 6 factorial design (4 × 3 × 6 = 72 plots) for each of 3 silage harvest periods in 2018, and repeated in 2019. Herbage samples and yield measurements were collected weekly for weeks 2–7 post fertilizer application, and herbage harvested after seven weeks regrowth was ensiled and silage was analysed after 100 days. There were no significance differences overall between responses of CAN and SU fertilized plots in terms of grass dry matter (DM) yield and quality parameters (acid detergent fibre (ADF), ash, buffering capacity (BC), metabolisable Energy (ME), nitrate (NO32−), nitrogen (N), or water soluble carbohydrate (WSC) or silage quality parameters (DM, volatile corrected organic dry matter (VCODM), ammonia nitrogen as a fraction of total nitrogen (NH3‐N/ Total N), pH, crude protein (CP), lactic acid (LA), acetic acid (AA), propionic acid (PA), butyric acid (BA), ethanol, propanol, ADF, ash, WSC or dry matter digestibility (DMD). Numerous significant differences between week and between cut were identified for grass quality, silage quality and grass ensilability parameters, and in the grass DM yields recorded. However, in many instances there was no associated treatment effect identified. There were no significant interactions between CAN and SU treatments and either cut, or week for nitrate concentration or yield. Variance of nitrate concentration was highest at the third cut and indicates a reduction in the nitrogen use efficiency of the 3rd cut silage harvest, potentially demonstrating a need to reduce fertilizer application recommendations for late‐season silage harvests. Overall, the results of this study support the hypothesis that replacing the currently favoured CAN fertilizer products with SU will not impact production of grass silage in Northern Ireland, meaning SU can be confidently adopted by farmers as a mitigation strategy to reduce farm nitrogenous emissions without reducing levels of sward productivity. This study recorded average annual grass silage DM yields of 15.5 and 16.1 t DM/ha from the CAN and SU fertilizer treatments respectively, which were not significantly different. In addition, the yield gain response to the application of each fertilizer type were not significantly different at 21.51 and 23.24 kg of DM produced for every kg of N applied as SU or CAN respectively, relative to control plots receiving 0 nitrogen.

A Novel Electrochemical Strategy for the Highly Sensitive Investigation of Tinidazole Using Newly Designed Halloysite Nano Clay and TiO2 Based Sensor

A voltametric technique with high sensitivity has been introduced to perform the electrochemical reduction of Tinidazole (TDZ), a significant antihistamine medication employed to combat infections instigated by various protozoans like Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis. This method employs a Titanium oxide and halloysite nano clay modified Glassy Carbon electrode (TiO2-HNC/GCE), which displayed remarkable sensitivity and selectivity in detecting TDZ. The electrode characterization was carried out by XRD and SEM-EDS. The analysis of TDZ explored using cyclic voltammetry (CV) and square wave voltammetry (SWV). The best reduction activity of TDZ was observed in pH of 7.0. The process was determined to be irreversible and controlled by diffusion. Through concentration variance assessments, a linear range of 1.0 μM to 10.0 μM was established. Detection and quantification limits were computed to be 14 nM and 46.9 nM, which is superior to reported works. The practical utility of the modified sensor was verified to detect TDZ concentration in pharmaceutical and biological samples. The investigation of various parameters indicated the sensor’s stability, and sensitivity in yielding valuable outcomes and can be used in pharamaco-kinetics and quality control laboratories.

Land-Use Regression Analysis of Summer Tropospheric Ozone Concentrations in Ireland

Tropospheric ozone is a powerful oxidant that can damage living organisms; it is widely monitored, as air concentrations have more than doubled since the Industrial Revolution. However, in general air quality monitoring stations are limited spatially to large urban centres; accordingly, accurate prediction of concentrations outside of cities is important for protecting human and plant health. Land-use regression has been successfully used for modelling air pollutant concentrations by establishing a relationship between observed concentrations and landscape features representing sources and sinks. In this study, we developed a land-use regression model that explained 68% of the variance of summer average ozone concentrations in the Republic of Ireland. Ozone was measured at 14 active and 20 passive monitoring sites; air concentrations varied spatially, with the highest ozone measured in rural upland (64.5 µg/m3) and Atlantic coastal (50.2–60.5 µg/m3) sites and the lowest generally in urban centres (38.9–45.7 µg/m3). A total of 74 land-use predictor variables were tested, and their inclusion in the model was based on their impact on the coefficient of determination (R2). The final model included variables linked primarily to deposition processes and included “forest woodland and scrub area” and “distance to coast”. The meteorological variable “rain” and an indicator for NOx emissions “distance to EPA Integrated Pollution Control facilities” were also included in the final model. Our results demonstrate the potential effectiveness of land-use regression modelling in predicting ozone concentrations, at a scale relevant for ecosystem protection.

Rainfall-driven resuspension of pathogenic Leptospira in a leptospirosis hotspot

Leptospirosis is a zoonosis caused by Leptospira bacteria present in the urine of mammals. Leptospira is able to survive in soils and can be resuspended during rain events. Here, we analyzed the pathogenic Leptospira concentration as a function of hydrological variables in a leptospirosis hot spot. A total of 226 samples were collected at the outlet of a 3 km2 watershed degraded by ungulate mammals (deer and feral pigs) and rats which are reservoirs for leptospirosis. Water samples collected at the beginning of a rain event following a dry period contained high concentrations of pathogenic Leptospira. The concentration was generally correlated with the water level and the suspended matter concentration (SMC) during the main flood event. A secondary peak of pathogenic Leptospira was sometimes detected after the main flood and in slightly turbid waters. Lastly, the pathogenic Leptospira concentration was extremely high at the end of a wet season. The pathogenic Leptospira concentrations could not be explained by a linear combination of hydrological variables (e.g. the rainfall, water level, SMC and soil moisture). However, nonlinear machine learning models of rainfall data only provided a fair fit to the observations and explained 75 % of the variance in the log10-transformed pathogenic Leptospira concentration. A comparison of identical machine learning models for the water level, SMC and pathogenic Leptospira concentration showed that the residual error in the Leptospira concentration was due to not only the small dataset but also the intrinsic characteristics of the signal. Our results support the hypothesis whereby pathogenic Leptospira survive at different depths in soils and superficial river sediments (depending on their water saturation) and are transferred to surface water during erosion. These results might help to refine leptospirosis warnings given to the local population. Future research should be focused on larger watersheds in more densely populated areas.

Differentiating gastric schwannoma from gastric stromal tumor (≤5 cm) by histogram analysis based on iodine-based material decomposition images: a preliminary study.

This study aims to investigate the value of histogram analysis based on iodine-based material decomposition (IMD) images obtained through dual-energy computed tomography (DECT) to differentiate gastric schwannoma (GS) from gastric stromal tumor (GST) (≤5 cm) preoperatively. From January 2015 to January 2023, 15 patients with GS and 30 patients with GST (≤5 cm) who underwent biphasic contrast-enhanced scans using DECT were enrolled in this study. For each tumor, we reconstructed IMD images at the arterial phase (AP) and venous phase (VP). Nine histogram parameters were automatically extracted and selected using MaZda software based on the IMD of AP and VP, respectively, including mean, 1st, 10th, 50th, 90th, and 99th percentile of the iodine concentration value (Perc.01, Perc.10, Perc.50, Perc.90, and Perc.99), variance, skewness, and kurtosis. The extracted IMD histogram parameters were compared using the Mann-Whitney U-test. The optimal IMD histogram parameters were selected using receiver operating characteristic (ROC) curves. Among the IMD histogram parameters of AP, the mean, Perc.50, Perc.90, Perc.99, variance, and skewness of the GS group were lower than that of the GST group (all P < 0.05). Among the IMD histogram parameters of VP, Perc.90, Perc.99, and the variance of the GS group was lower than those of the GST group (all P < 0.05). The ROC analysis showed that Perc.99 (AP) generated the best diagnostic performance with the area under the curve, sensitivity, and specificity being 0.960, 86.67%, and 93.33%, respectively, when using 71.00 as the optimal threshold. Histogram analysis based on IMD images obtained through DECT holds promise as a valuable tool for the preoperative distinction between GS and GST (≤5 cm).

The effect of ambient air pollution on birth outcomes in Norway

BackgroundAmbient air pollution can be harmful to the fetus even in countries with relatively low levels of pollution. Most of the established literature estimates the association between air pollution and health rather than causality. In this paper, I examine the causal effects of ambient air pollution on birth outcomes in Norway.MethodsWith the large sample size and geographic division of sub-postal codes in Norway, I can control for a rich set of spatio-temporal fixed effects to overcome most of the endogeneity problems caused by the choice of residential area and date of delivery. After controlling for a rich set of spatio-temporal fixed effects, my paper uses the variance in ambient air pollutant concentrations over narrow time intervals and in a small geographic area of Norway to determine how prenatal air pollution exposure affects birth outcomes. My data contain extensive information about parents as well as meteorological conditions that can be used to control for potential confounding factors.ResultsI find that prenatal exposure to ambient nitric oxide in the last trimester causes significant birth weight and birth length loss under the same sub-postcode fixed effects and calendar month fixed effects, whereas other ambient air pollutants such as nitrogen dioxide and sulfur dioxide appear to be at safe levels for the fetus in Norway. In addition, the marginal adverse effect of ambient nitric oxide is larger for newborns with disadvantaged parents. Both average concentrations of nitric oxide and occasional high concentration events can adversely affect birth outcomes.ConclusionsPrenatal exposure to NO pollution has an adverse effect on birth outcomes. This suggests that government and researchers should pay more attention to examining NO pollution and that health care providers need to advise pregnant women about the risks of air pollution during pregnancy.

Meta-GWAS on PCSK9 concentrations reveals associations of novel loci outside the PCSK9 locus in White populations

Background and aimsProprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of lipid homeostasis. A few earlier genome-wide association studies (GWAS) investigated genetic variants associated with circulating PCSK9 concentrations. However, uncertainty remains about some of the genetic loci discovered beyond the PCSK9 locus. By conducting the largest PCSK9 meta-analysis of GWAS (meta-GWAS) so far, we aimed to identify novel loci and validate the previously reported loci that regulate PCSK9 concentrations. MethodsWe performed GWAS for PCSK9 concentrations in two large cohorts (GCKD (n = 4,963) and KORA F3 (n = 2,895)). These were meta-analyzed with previously published data encompassing together 20,579 individuals. We further conducted a second meta-analysis in statin-naïve individuals (n = 15,390). A genetic risk score (GRS) was constructed on PCSK9-increasing SNPs and assessed its impact on the risk for coronary artery disease (CAD) in 394,943 statin-naïve participants (17,077 with events) of the UK Biobank by performing CAD-free survival analysis. ResultsNine loci were genome-wide significantly associated with PCSK9 concentrations. These included the previously described PCSK9, APOB, KCNA1/KCNA5, and TM6SF2/SUGP1 loci. All imputed SNPs in the PCSK9 locus account for ∼15% of variance of PCSK9 concentrations. We further identified FADS2 as a novel locus that was also found in statin-naïve participants. All imputed SNPs within the FADS2 locus explain ∼1.2% of variance of PCSK9 concentrations. Additionally, four further loci (a region on chromosome 5, SDK1, SPATA16 and HPR) were genome-wide significant in either the main model or the statin-naïve subset. The linear increase in a PCSK9 genetic risk score was associated with 1.41-fold (95%CI 1.16–1.72, p < 0.001) higher risk for incident CAD. ConclusionsWe identified five novel loci (FADS2, SPATA16, SDK1, HPR and a region on chromosome 5) for PCSK9 concentrations that would require further research. Additionally, we confirm the genome-wide significant loci that were previously detected.