24-hour Samples Research Articles

Polycyclic Aromatic Compounds in Ambient PM2.5 in the Central Region of Ghana: Molecular Distribution, Origin and Cancer Risk Assessment

The distribution, sources and the cancer risk of human exposure to PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) were investigated in this work. Airborne particulate samples were obtained at the Winneba highway junction (WHJ) and Apam fish-smoking community (AFC) in the Central Region of Ghana from July 2022 to June 2023. PM2.5 particulates were collected using a Gent sampler equipped with a Gast pump and a stacked filter unit. 24-hour sampling was done two times a month using Teflon filters. Dichloromethane and gas chromatography with a mass spectrometer (GC-MS) were used to extract and analyse the samples, respectively, to identify 14 PAH compounds. The study discovered average PAH concentrations of 67.38 ng/m3 at WHJ and 41.59 ng/m3 at AFC. PAH profile was predominated with Phenanthrene, accounting for 25-27 % of total PAHs. The distribution pattern of PAHs was LMW>HMW>MMW at the two research sites. A strong correlation was found among BaA, BkF, BbF and BeP. The diagnostic ratio model revealed that PAHs stemmed from pyrogenic sources. The carcinogenic PAHs (BaP, BaA, Chr, BbF, BkF, BghiP) contributed approximately 90 % to the carcinogenic activity of total PAHs, denoting a high cancer potential of PAHs. The mean levels of BaP were about 8-10 times higher than the permissible limit of 1 ng/m3. The overall cancer risk values for exposure to PAHs via inhalation were more than 10-4, signifying high cancer risks: 11.61×10-4-21.14×10-4 for children and 19.91×10-4-36.24×10-4 for adults. Reducing PM2.5 and its health effects requires the use of clean fuel and the adoption of eco-friendly transportation.

Long-term investigation on the daily variability of microplastic concentration and composition - Monitoring in the effluent of a wastewater treatment plant

The discharge of treated wastewater into receiving waters by wastewater treatment plants (WWTPs) is considered as one of the main pathways for microplastics (MPs) to enter the environment. To gain a better understanding of the temporal variability of MPs in WWTP effluents, this study investigated the concentration and composition (size, shape and polymer type) of MPs in the effluent of a German WWTP over the course of one month. 24-hour mixed samples were collected daily by a custom built automated sampling unit for MPs. Particles and fibers ≥11 μm were analyzed using Fourier transform infrared microspectroscopy. The MP concentration showed large daily fluctuations and ranged between 9.64 103 m−3 and 8.44 104 m−3 MPs over the study period. However, there was no significant correlation between the MP concentration and the precipitation or discharge from the WWTP. In contrast to the MP concentration, the MP composition in terms of size and shape was consistent over the study period. There were strong correlations between the time series of the polymer types polypropylene, polyethylene, polystyrene, polyester, ethylene-vinyl-acetate, cellulose artificially modified as well as the polymer cluster acrylates/polyurethanes/varnish. The time series of polyamide showed no significant correlation with the time series of any other polymer type. This study established a one month long high-resolution time series of MP concentration and composition, and thus provides a valuable basis for future research on the temporal variability of MP inputs into the environment from WWTP effluents.

The Association of Serum Fibrinogen Levels With the Severity of Primary Postpartum Hemorrhage: A Prospective Study.

Postpartum hemorrhage (PPH) remains a major cause of maternal mortality and morbidity worldwide. Coagulation disorders are a major risk factor for PPH that have not been studied adequately. Fibrinogen, a plasma glycoprotein, is integral to hemostasis and is involved in the final process of the coagulation cascade. Fibrinogen levels increase with advancing pregnancy probably because of an increase in estrogen levels and reach a peak (~5g/L) in the third trimester of pregnancy. However, in the postpartum period, the fibrinogen concentration shows a decreasing trend. The purpose of the study was to study the serum fibrinogen levelin patients with PPH and to find its association with the severity of primary postpartum hemorrhage. Methodology: Patients were selected according to inclusion and exclusion criteria. Written and informed consents were taken. Routine investigations were done on admission and special investigations like red blood cell count, prothrombin time, international normalized ratio,activated partial thromboplastin time, and serum fibrinogen were done later when the patient developed PPH. Serial samples of all PPH patients for serum fibrinogen levels at0, 1, 2, 4, and 24 hours were taken to study the serum fibrinogen levels and data were analyzed. Result: The mean fibrinogen level on admission was 3.92 ± 0.92 g/lin non-severe PPH and 2.03 ± 0.97 g/l in the severe PPH group.Fibrinogen levels in the non-severe group remained < 4.46 g/l at 0, 1, 2, 4, and 24 hours. In the severe group, fibrinogen levels were < 2.89 g/l at 0, 1, 2, and 4 hours and it was 2.44 ± 1.06g/l in the 24-hour samples. Statistical significance was found in all the fibrinogen values among the two study groups (p = 0.001). Our results showed that zero-hour fibrinogen levels correlate significantly with the aggravation of PPH and levels <2 g/L can serve as a predictor for progression to severe PPH.

8342 A Rare Case of a Corticotropic and Gonadotropic Pituitary Double Adenoma

Abstract Disclosure: S. Gruber: None. D. Kirschenbaum: None. T. Hortobagyi: None. C. Serra: None. A. Bink: None. F. Beuschlein: None. Z. Erlic: None. Background: Pituitary adenomas account for about 15% of all intracranial neoplasms and typically arise from monoclonal proliferation of anterior pituitary cells. While lactotropic and clinically hormone-inactive adenomas make up by far the largest proportion, somatotropic and corticotropic adenomas have a significantly lower prevalence. This case describes the very rare finding of a corticotropic and gonadotropic double adenoma. Clinical Case: A 63-year-old Caucasian man (BMI 36.7 kg/m2) presented in the obesity clinic. Hypercortisolism was suspected by repeated lack of cortisol suppression in low-dose dexamethasone suppression tests [minimal 87 nmol/l] and disrupted circadian rhythm of cortisol secretion according to salivary cortisol profile. Cortisol levels in a 24-hour sample of urine were normal. ACTH levels were elevated [73 ng/l; n&amp;lt;61 ng/l] leading to suspicion of Morbus Cushing. Concomitant diseases include sleep apnea, arterial hypertension and newly diagnosed type 2 diabetes mellitus. Medical history was notable for deep vein thrombosis and pulmonary embolism. Other stigmata of hypercortisolism were not evident. The rest of endocrine work up confirmed partial secondary hypothyroidism and hypogondotropic hypogonadism. An MRI of the pituitary gland revealed a pituitary macroadenoma with a maximum dimension of 20 mm. The patient underwent an endoscopic transnasal adenomectomy with post-operative corticotropic insufficiency. Contrary to our expectations, the histological examination of the surgical resection revealed a gonadotrophic pituitary adenoma with SF1 and focal FSH expression. The discrepancy between clinical, biochemical and histological findings led to subsequent examinations of the specimen with detection of an small fragment accounting for less than 5% of the total sample with expression of T-Pit and ACTH but neither SF1 nor Pit-1, corresponding to an additional corticotropic adenoma with densely granulated pattern. The tumor cells did not show overlapping expression patterns of transcription factors or hormones, which indicates the coincidence of two distinct adenomas. Three months postoperatively, the patient is biochemically cured. Partial anterior pituitary insufficiency remained. Conclusion: Pituitary double adenomas are found in 0.5-1.5% of all surgical specimens. They are characterized by their origin from different cell lines, which distinguishes them from plurihormonal adenomas, which originate from one single cell line. Here we demonstrate a SF1-T-Pit lineage combination resulting in a neighboring ACTH and FSH-adenoma. In this particular case, the clinically relevant corticotropic adenoma was comparatively tiny, making it easy to miss. This illustrates well the importance of careful correlation of clinical, laboratory and histologic findings as correct diagnosis is crucial for postoperative patient management. Presentation: 6/2/2024

Microplastics comparison of indoor and outdoor air and ventilation rate effect in outskirts of the Seoul metropolitan city

Microplastics in the air are becoming a concern, especially in indoor environments. Outdoor microplastics can travel from far spaces while indoor ones remain suspended and recirculate in the indoor environment. In this study, we collected air samples from the same buildings indoors and outdoors and observed the indoor microplastic concentration was 1.8 times higher than the outdoor. 24-hour sampling was performed with a mini-volume air sampler at the rate of 5 L/min. In this study, along with a comparison of indoor and outdoor concentrations, we also studied the microplastics' type size, and shape. We found that fiber-type microplastics account for nearly 90 % of the total and synthetic fibers. We also reported the 10 highest present microplastics are Polyethylene, Polyethersulfone, Polyamide, Polystyrene, Acrylic, Polyvinyl Chloride, Polytetrafluoroethylene, Alkyd, and Polyurethane. It is also observed the indoor ventilation rate plays a major role in the microplastic concentrations, long and periodic ventilation resulted in the lower concentration of the indoor microplastics. This study resulted in higher indoor air concentrations than outdoor and even in the outskirts of the metropolitan city which shows that indoor air concentrations are dependent on indoor sources and human activity.

Natural vs. anthropogenic sources of N-Nitrosodimethylamine precursors in surface water

N-nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct formed from reactions between dichloramine and organic nitrogen-containing precursors. It is unclear if NDMA precursors in surface water intakes originate in anthropogenic (i.e., wastewater) or natural sources. The Truckee River has a single point source release of treated wastewater effluent, making it an ideal system to study the relative importance of precursor sources. Three Lagrangian sampling events were conducted. NDMA formation potential (FP, a measurement of precursors) above the wastewater outfall indicated that the natural background of NDMA precursors was 2-28 ng/L. NDMA FP increased to 18-31 ng/L immediately downstream of the wastewater outfall, but decreased rapidly in a first order manner, and were not statistically different from the upstream samples in only ∼6 km. This suggests that the dominant source of NDMA precursors may be wastewater derived only near wastewater outfalls and deviates from the previous belief that wastewater-derived precursors are responsible for NDMA formation in drinking water sources located further downstream. Additionally, given the rapid loss of the wastewater precursors in this study, precursors which are slow to biodegrade/photolyze/adsorb to sediment are likely to be poor surrogates for the overall wastewater NDMA precursor pool. To understand temporal changes in the wastewater impact on environmental NDMA precursor loading, two 24-hour sampling events were conducted near (<3 km) the wastewater outfall and demonstrated that temporal changes in the NDMA precursors directly downstream of the wastewater outfall are directly linked to the wastewater flow contribution.

Winter indoor air quality in traditional Mongolian yurts, in a Ger district of Ulaanbaatar

In Ulaanbaatar roughly 60 % of the population live in traditional Mongolian yurts in the so-called Ger districts of the city. Winter indoor air quality is a serious concern in these districts as about 98 % of households consume solid fossil fuel (mainly coal). In our study, indoor air quality was assessed based on PAHs analysis and ecotoxicity testing of 24-hour samples collected in 4 yurts. Three of the selected yurts were equipped with conventional while the fourth one with improved stoves. Analysis of PAHs profiles showed the prevalence of higher molecular weight PAHs in all yurts. Concentrations of the 5-ring benzo(b)fluoranthene and 6-ring benzo(g.h.i)perylene were extremely high in one yurt using conventional stove, 8430 µg g−1 and 6320 µg g−1, respectively. Ecotoxicity of the samples was assessed using the kinetic version of the Vibrio fischeri bioluminescence inhibition bioassay. In concordance with PAHs concentrations, ecotoxicity was also the highest in that yurt.

Storage Induced Alterations in Erythrocyte Morphology and Platelet Count

Background: Examination of blood smears and various hematologic parameters is the first step in assessment of hematologic function and diagnosis of possible underlying diseases. The aim of this study was to identify artefacts in stored red blood cells and classify the occurrence of such alterations according to the age of the stored sample. This studyalso aimed to note the changes in platelet count dispatched by automated hematology coulter in such stored blood samples. Material and Methods: A prospective cross sectional study was conducted from the EDTA anticoagulated blood samples of 100 patients received in the department of Pathology after receiving ethical approval from the institutional review committee. All the samples were analyzed in 4 occasions i.e. within 2 hours, at 24 hours, at 48 hours and at 96 hours. Analysis was carried out by Sysmex 5 part analyzer for platelet counts and the Leishman stained blood films were examined to note changes in the erythroctyte morphology. Results: There was alterationsin platelet counts in 22% cases between 2-hour samples and other samples. The red blood cell morphology was not different among 2 hours samples and 24 hours sample. However, the red blood cell morphology was altered in 48 hours samples and 96 hours samples. Conclusion: Storage of EDTA anticoagulated blood even upon refrigeration can cause changes in platelet counts as well as morphology of red blood cells. Changes in red blood cells are not significant till 24 hours while the platelet counts may alter within 24 hours.

Effect of Instrument Lubricant on Mechanical Properties of Restorative Composite.

Using a wetting resin or adhesive system as an instrument lubricant when placing composite layers is commonly practiced to improve handling. This study investigated whether instrument lubricants affected strength, stiffness, or hardness. Composite beams (TPH Spectra) were fabricated using a stainless steel mold (25×2.5×2 mm) in two steps, where the second half (12.5 mm) was added and cured against a cured first half (n=15). The composite surface at the open end of the first half was smoothed using an instrument lubricated with wetting resin (Ultradent) or universal adhesive (ScotchBond Universal), enough to prevent sticking, or without lubrication. An additional beam of each group was characterized using scanning electron microscopy. Monolithic specimens were also fabricated. After 24 hour storage (37°C, 100% humidity), the beams' flexural strength and stiffness were determined by four-point bending. Vickers surface hardness was measured on 24-hour composite samples in 2 mm deep acrylic cavities, cured after the surface was smoothed with the two instrument lubricants or no lubricant (n=10). Hardness was remeasured after finishing with a series of contouring and polishing discs. Data were statistically analyzed using ANOVA followed by Student-Newman-Keuls post hoc test at 0.05 significance level. There were significant differences (p<0.001) in flexural strength and stiffness among groups. While strength and stiffness were not affected by using a wetting resin as instrument lubricant, use of a universal adhesive increased strength and stiffness significantly, achieving monolithic values. Scanning electron micrographs showed less porosities at the interface when using instrument lubricants. Surface hardness was significantly reduced in groups in which instrument lubricants were used, but finishing/polishing restored original hardness (p<0.001). Lubricating an instrument with a wetting agent did not adversely affect physical or surface properties, provided the surface was finished and polished. If a universal adhesive was used as lubricant, the strength and stiffness of a layered composite could be increased, reaching monolithic values.

Assessment of Urinary Stone Chemical Compositions and Prevalence of Metabolic Disorders Among Urolithiasis Patients in Northern Sri Lanka: A Prospective Study.

Introduction Urolithiasis, a common urological disorder affecting the global population, demonstrates geographical diversity due to factors such as water quality, climate variations, health conditions, and dietary habits. This study, conducted in Northern Sri Lanka, examines urinary stone compositions and assesses the prevalence of metabolic disorders among urolithiasis patients. Methods This prospective cross-sectional study, conducted at Jaffna Teaching Hospital, Jaffna, Sri Lanka, from July 2022 to June 2023, focused on surgically treated urolithiasis patients. Institutional ethical clearance was obtained. Patient details and investigational findings were collected through questionnaires and data extraction forms. Stone analysis utilized Fourier transform infrared spectroscopy, and a detailed metabolic evaluation of a 24-hour urine collection sample was carried out. Results This study followed 153 surgically treated urolithiasis patients, primarily male (64.3%), with a mean age of 48.64. Ureteric colic (48.4%) was common, with kidney stones (45.8%) prevalent; 57.52% had recurrent stones. Diabetes mellitus (DM; 23.5%) was the top comorbidity. Calcium oxalate monohydrate (COM) stones (78.4%) were the most frequent, followed by uric acid (12.4%). COM predominated in the 40-59 age group. There was no significant gender-stone type association. A total of 86.9% had metabolic abnormalities, notably hypocitraturia (60.1%). Moreover, 23% had both hypocitraturia and hypomagnesuria. Some metabolic disorders showed gender differences, with a marginal age-metabolic disorder association (p < 0.061). Urine oxalate levels were normal, with higher variability in males. Conclusion Middle-aged males with urolithiasis commonly presented with ureteric colic and predominantly had COM stones. Recurrent stones were common, often accompanied by metabolic abnormalities such as hypocitraturia and hypomagnesuria, with DM as the primary comorbidity.

Investigation of occurrence of aromatic amines in municipal wastewaters using passive sampling

Aromatic amines (AAs) are human-made compounds known for their mutagenic properties, entering surface waters from various sources, often originating as transformation products of dyes or pesticides. Despite their low concentrations in surface waters, AAs can exhibit mutagenicity. Our study focused on evaluating three passive samplers (PSs) for enriching these compounds from influent and effluent of a wastewater treatment plant (WWTP) in Brno, Czech Republic. The PSs tested included variants containing AttractSPE™ SDB-RPS sorbent disk, one with and one without a diffusive agarose hydrogel layer, and a modified Speedisk (Bakerbond Speedisk® H2O-Philic). PSs were deployed in wastewater (WW) for one to four weeks in various overlapping combinations, and the uptake of AAs to PSs was compared to their concentrations in 24-hour composite water samples. A targeted LC/MS analysis covered 42 amines, detecting 11 and 13 AAs in daily composite influent and effluent samples, respectively. In the influent, AAs ranged from 1.5 ng L−1 for 1-anilinonaphthalene to 1.0 μg L−1 for aniline, and the highest concentration among all measured amines was observed for cyclohexylamine at 2.9 μg L−1. In the effluent, concentrations ranged from 0.5 ng L−1 for 1-anilinonaphthalene to 88 ng L−1 for o-anisidine. PSs demonstrated comparable accumulation of amines, with integrative uptake up to 28 days in both influent and effluent and detection of up to 23 and 27 amines in influent and effluent, respectively; altogether 34 compounds were detected in the study. Sampling rates (Rs) were estimated for compounds present in at least 50 % of the samples and showing <40 % aqueous concentration variability, with robustness evaluated by comparing values for compounds in WWTP influent and effluent. Although all devices performed similarly, hydrogel-based PS exhibited superior performance in several criteria, including time integration and robustness of sampling rates, making it a suitable monitoring tool for AAs in WW.

Modification of Staphylococcal aureus quorum sensing and virulence factor expression by cold plasma treatment

Abstract Staphylococcal aureus (S. aureus) resides in biofilms and produces virulence factors. Cold atmospheric plasma treatment can be used to kill and reduce bacteria virulence expression. This study will observe the effects of cold plasma treatment on S. aureus killing, biofilm disruption, virulence factor, and quorum sensing gene expression in vitro and in vivo. S. aureus biofilms were grown in vitro on discs and then treated with plasma (J-Plasma; Apyx Medical Inc.) CFU counts, Crystal Violet Staining, and SEM were conducted to determine biofilm disruption and killing. Gene expression was determined by qPCR for Superoxide dismutase (SodA), Panton-Valentine Leukocidin (luk-PV), alpha-hemolysin (Hla), and AgrB and SarA. A similar study was performed on muscles infected in a rat model, treated and untreated, at Days 0, 4 and 14. Cold plasma-treated biofilms on discs had significantly less bacterial CFU counts, lower crystal violet absorbance, and visible disturbances of biofilm. qPCR showed a significant reduction of virulence factor and quorum signaling genes. In vivo, all day 4 and 14 muscle samples had significantly higher CFU counts than 6-hour samples. Results showed a fold change reduction after plasma treatment in virulence and quorum sensing gene expression. Cold plasma treatment disrupts S. aureus biofilm formation and gene expression, both in vivo and in vitro, highlighting the potential of cold plasma treatment to aid in the clearance of S. aureus infections.

Effect of Air Pollutants on Allergic Inflammation in Structural Cells of the Nasal Mucosa.

Air pollution is an increasing global concern, and its effect on allergic inflammation has attracted the attention of many researchers. Particulate matter (PM) is a major component of ambient air pollution, and heavy metals are the primary toxic constituents of PM. As previous studies on the impact of air pollutants on allergic inflammation did not adequately mimic real-world atmospheric exposure, we developed an experimental model to investigate the effects of aerosolized air pollutants on nasal epithelial cells and fibroblasts. We collected particulate matter 2.5 (PM2.5) samples from ambient 24-hour air samples obtained in Seoul from August 2020 to August 2022, and then conducted component analysis for metallic constituents. Primary nasal epithelial cells and nasal fibroblasts, obtained and cultured from the turbinate tissues of human participants, were treated with PM2.5. The associations of heavy metals identified from the component analysis with cytokine expression were investigated. A three-dimensional (3D)-hybrid culture model, consisting of co-culture of an air-liquid interface and nasal fibroblast spheroids, was constructed to observe the impact of aerosolized air pollutants. Among the heavy metals, Si was the predominant component of PM2.5, and Zn showed the highest correlation with the concentration of PM2.5 in Seoul. PM2.5, Zn, and Si increased the production of epithelial cell-derived cytokines, and PM2.5 and Zn exhibited similar trends with one another. Exposure of the 3D-hybrid model to aerosolized PM2.5 and Zn resulted in elevated periostin, alpha-smooth muscle actin, and fibronectin expression in fibroblast spheroids, and those without an epithelial barrier exhibited a similar increase in periostin expression. Ambient air pollutants in the form of aerosols increase the expression of allergic inflammatory cytokines in both nasal epithelial cells and fibroblasts. Regulations on air pollution will help reduce the global burden of allergic diseases in the future.

Influence of cryogenic treatment time on the mechanical properties of AZ31 magnesium alloy sheets after cross-rolling

To investigate the influence of cryogenic treatment time on the mechanical properties and the microstructure of the AZ31 Mg alloy sheets, the different times of cryogenic treatment after two-pass cross-rolling were carried out at air-cooling, 1 hour, 3 hours and 6 hours. The consequences of the tensile experiment illustrated that the cross-rolling Mg alloy with 1-hour cryogenic treatment showed the highest ultimate tensile strength (343 MPa), which was 9.6%, 9.6% and 11.7% higher than air-cooling, 3-hour cryogenic and 6-hour cryogenic samples. The primary reasons for this include fine-grained strengthening, twin strengthening, low-angle grain boundaries (LAGBs) strengthening, dislocation strengthening and precipitation strengthening. The internal grain of the magnesium alloy sheet after 1 hour of cryogenic treatment was refined to 5.2 μm. The {10−11} contraction twin, {10−12} extension twin and {10−12}-{10−11} double twin were surveyed according to the electron backscatter diffraction (EBSD) results. On the <11–20> axis, all the four samples exhibited the {0001} basal texture. And the sample of 1-hour cryogenic treatment exhibited the highest basal texture intensity. According to the micro-structure observation, high-density dislocation and several precipitates were illustrated in the sample of 1-hour cryogenic treatment.

Wastewater Surveillance for Identifying SARS-CoV-2 Infections in Long-Term Care Facilities, Kentucky, USA, 2021-2022.

Persons living in long-term care facilities (LTCFs) were disproportionately affected by COVID-19. We used wastewater surveillance to detect SARS-CoV-2 infection in this setting by collecting and testing 24-hour composite wastewater samples 2-4 times weekly at 6 LTCFs in Kentucky, USA, during March 2021-February 2022. The LTCFs routinely tested staff and symptomatic and exposed residents for SARS-CoV-2 using rapid antigen tests. Of 780 wastewater samples analyzed, 22% (n = 173) had detectable SARS-CoV-2 RNA. The LTCFs reported 161 positive (of 16,905) SARS-CoV-2 clinical tests. The wastewater SARS-CoV-2 signal showed variable correlation with clinical test data; we observed the strongest correlations in the LTCFs with the most positive clinical tests (n = 45 and n = 58). Wastewater surveillance was 48% sensitive and 80% specific in identifying SARS-CoV-2 infections found on clinical testing, which was limited by frequency, coverage, and rapid antigen test performance.

Modelled sources of airborne microplastics collected at a remote Southern Hemisphere site

Airborne microplastics have emerged in recent years as ubiquitous atmospheric pollutants. However, data from the Southern Hemisphere, and remote regions in particular, are sparse. Here, we report airborne microplastic deposition fluxes measured during a five-week sampling campaign at a remote site in the foothills of the Southern Alps of New Zealand. Samples were collected over 24-hour periods for the first week and for 7-day periods thereafter. On average, atmospheric microplastic (MP) deposition fluxes were six times larger during the 24-hour sampling periods (150 MP m−2 day−1) than during the 7-day sampling periods (26 MP m−2 day−1), highlighting the importance of sampling frequency and deposition collector design to limit particle resuspension. Previous studies, many of which used weekly sampling frequencies or longer, may have substantially underestimated atmospheric microplastic deposition fluxes, depending on the study design. To identify likely sources of deposited microplastics, we performed simulations with a global dispersion model coupled with an emissions inventory of airborne microplastics. Modelled deposition fluxes are in good agreement with observations, highlighting the potential for this method in tracing sources of deposited microplastics globally. Modelling indicates that sea-spray was the dominant source when microplastics underwent long-range atmospheric transport, with a small contribution from road dust.

Assessing the role of tidal cycle, waves, and wind as drivers of surf zone zooplankton on a temperate sandy beach

The surf zone is strongly affected by tides, waves, and winds. However, there are still a lack of knowledge about the response of the zooplankton community to these physical factors in the surf area, with a particular emphasis on tidal effects. The aim of this study was to conduct a preliminary assessment of two distinct tidal cycles, encompassing fluctuations in on-offshore currents, waves, and wind and their influence on the surf zooplankton community of Pehuen Co (PC) sandy beach, Argentina. The study involved field sampling at a single station in the surf zone on September 4th, 2018, and May 20th, 2019. The sampling covered four tidal phases at 3-hour intervals, when water and zooplankton samples were collected for analysis. Environmental variables, such as current velocities, water level, and wind data, among others, were also registered. The results indicated that the abundance of surf zooplankton was significantly influenced by physical forces, resulting in distinct impacts. During the Sept 2018 tidal cycle (calm conditions), an on-offshore current emerged as the primary driving force, resulting in the highest abundance of zooplankton being observed at low tide. In contrast, during the May 2019 tidal cycle (southern winds), strong winds intensified the offshore current velocities and wave height, affecting the zooplankton abundance. High velocities of on-offshore currents corresponded to lower abundance of zooplankton at low tide. This situation introduced an extra physical force -the wind- playing a significant role in restructuring the dynamic of the zooplankton community. The preliminary analysis suggests that the relationship between environmental and biological data is complex and varies depending on the physical factors involved. Notably, in rough conditions, south winds can restructure zooplankton dynamics, influenced by strong winds. This work emphasizes the importance of the surf zone waters of sandy beaches and are useful for future research or monitoring programmes of similar high-energy ecosystems.

Validação das equações para estimativa da filtração glomerular ajustáveis por raça/cor em adultos de Vitória, Espírito Santo, Brasil

Abstract The assessment of renal function is performed using the glomerular filtration rate (GFR) whose measurement by creatinine clearance (ClCr) and is dependent on a 24-hour urine sample, hindering it use in primary healthcare. The equations that estimate GFR from serum creatinine make the test more accessible, however, their adjustments by race/color have been questioned in mixed populations. To test the agreement between CrCl and GFR estimated by formulas (Modification of Diet in Renal Disease [MDRD-4] and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), with or without adjusting for race/color, data were used from a sub-study of the National Health Survey (NHS) including 272 adults from Vitória/Espírito Santo who underwent a 24-hour urinary sampling. Analysis of variance (ANOVA) and the Bland-Altman method were adopted. There was adequate agreement between ClCr and equations, but the adjustment by race/color decreases the accuracy of both equations. In the race/color factor, there was similarity between groups for CrCl (p=0.21), suggesting that there is no difference in creatinine metabolism induced by skin color. It is concluded that MDRD and CKD-EPI equations perform satisfactorily in the evaluation of renal function, and the use of corrections for race/color is not recommended.

Correlation of Calcium, Magnesium, Uric Acid and Phosphate Levels in Serum, 24-Hour Urine, and Stone Components in Patients with Urolithiasis: A Cross-sectional Study

Introduction: Urolithiasis is the formation of stony concretions in the bladder or urinary tract. Nearly 10% of the population suffers from urolithiasis, which has a high chance of recurring. Many resources are used to treat urinary stones globally, but the need for prevention has been neglected. Aim: To determine the levels of Calcium (Ca), Phosphorus (P), Uric Acid (UA) and Magnesium (Mg) in the blood and urine of patients with urolithiasis, as well as in urinary stones post-procedure. Materials and Methods: This cross-sectional study was conducted at the Department of General Surgery at the Himalayan Institute of Medical Sciences (HIMS), Swami Ram Nagar, Dehradun, Uttarakhand, India, from November 2021 to October 2022. A total of 80 patients suffering from urolithiasis were involved in the study. Serum and 24-hour urinary samples were collected for quantitative analysis of Mg, Ca, UA and Phosphate (Ph) levels. Urinary stones postsurgery were sent to the biochemistry section of the reference laboratory for semi- quantitative colorimetric determination and morphological analysis. Spearman’s Rank correlation coefficient was used to correlate two quantitative variables and a p-value of &lt;0.05 was considered statistically significant. Results: In the study, 77.5% of the patients were males and 22.5% were females. Based on their fundamental components, a single calcium oxalate calculus was found in 39 patients. The levels of biochemical parameters associated with urinary stones were as follows: Ca component= 38.13±5.53 mg/dL; Mg component= 10.33±4.94 mg/dL; UA= 10.13±9.04 mg/dL; and Ph= 4.55±1.08 mg/dL. A strong positive correlation was observed between serum calcium and stone calcium (r=0.747, p=0.001) and between stone calcium and urine uric acid (r=0.813, p=0.001). Conclusion: A significant relationship was observed between stone calcium and serum calcium.

Dietary intake of methylmercury by 0-5 years children using the duplicate diet method in Japan.

The developing brains are sensitive to methylmercury (MeHg). However, the exposure to MeHg in baby foods and toddler meals remains unknown. This study aimed to determine MeHg intake from baby food or toddler meals, and to investigate the relationship with child hair total mercury (THg). A total of 3 days of 24-hour dietary diet and hair samples were collected from 260 consenting children aged 0-5 years. We measured the concentrations of THg and MeHg in the diet and THg in the hair. The results of measuring THg were below both the method detection and method quantification limits or either of both in powdered milk (93.8%), 5-6 months (53.3%), and 7-8 months (39.5%). The median daily THg intake was 20.3 (95% confidence interval 0.72-232.5) ng/kgbw. MeHg was not detected in 213 samples with dietary THg concentrations below 1 ng/g. The MeHg concentration with THg concentrations of 1 ng/g or higher was 1.70 (0.87-6.21) ng/g, and MeHg percentage in THg was 90.0%. To estimate MeHg intake, we multiplied the THg concentration by 90.0%, resulting in an estimated MeHg intake of 18.3 (0.65-209.2) ng/kgbw/day. The THg in children's hair was 1.05 (0.31-3.96) ppm, and a weak positive correlation was observed between hair THg and dietary MeHg (r = 0.170). This study highlights the accurate estimation of MeHg intake in children using a duplicate method. Japanese children consume fish, the MeHg intakes exceeded the reference dose and/or provisional tolerable weekly intake in several children. Further discussion based on epidemiological data is required.