Stable Concentrations Research Articles

Transdermal diffusion research on functional substances of Jingu Zhitong Gel

This study systematically explored the transdermal diffusion law of functional substances of Jingu Zhitong Gel(JGZTG). The transdermal diffusion research methods of JGZTG were investigated by single factor trial with the automated transdermal(dry-heat) sampling system. High performance liquid chromatography(HPLC) content determination method was established to determine the contents of ferulic acid, senkyunolide I, cinnamic acid, hydroxy-ε-xanthoxylin, hydroxy-α-xanthoxylin, and hydroxy-β-xanthoxylin in the transdermal diffusion solution of JGZTG. The transdermal diffusion law of the components within 16 h was investigated. The results showed that the optimal transdermal diffusion method of JGZTG was as follows: Rat skin was used as the transdermal barrier; normal saline was used as the receiving medium; the dosage of JGZTG was 0.3 g, and the receiving solution was extracted by ethyl acetate. The results of transdermal diffusion showed that the release of ferulic acid, cinnamic acid, and senkyunolide I increased significantly at 0-8 h and slowed down at 8-16 h. The drug release was a synergic process of diffusion and dissolution, in which ferulic acid and cinnamic acid followed Higuchi and Ritger-Peppas equations, and liguolactone I followed Higuchi equation. The transdermal diffusion curves of hydroxy-ε-zanthoxylin, hydroxy-α-zanthoxylin, and hydroxy-β-zanthoxylin showed continuous release within 16 h, and the drug release was skeleton dissolution. The diffusion law followed zero-order equation, first-order equation, and Ritger-Peppas equation. In clonclusion, it is a controlled release of ferulic acid, ligustrone I, cinnamic acid, hydroxy-ε-pyrroxylin, hydroxy-α-pyrroxylin, and hydroxy-β-pyrroxylin in JGZTG, which can maintain stable blood drug concentration with 16 h, and the cumulative transmittance of each component with 12 h can reach 80% of cumulative transmittance with 24 h, which is in line with the clinical drug use law of bis in die.

Towards a reference material for microplastics’ number concentration—case study of PET in water using Raman microspectroscopy

Increasing demand for size-resolved identification and quantification of microplastic particles in drinking water and environmental samples requires the adequate validation of methods and techniques that can be used for this purpose. In turn, the feasibility of such validation depends on the existence of suitable certified reference materials (CRM). A new candidate reference material (RM), consisting of polyethylene terephthalate (PET) particles and a water matrix, has been developed. Here, we examine its suitability with respect to a homogeneous and stable microplastic particle number concentration across its individual units. A measurement series employing tailor-made software for automated counting and analysis of particles (TUM-ParticleTyper 2) coupled with Raman microspectroscopy showed evidence of the candidate RM homogeneity with a relative standard deviation of 12% of PET particle counts involving particle sizes >30 µm. Both the total particle count and the respective sums within distinct size classes were comparable in all selected candidate RM units. We demonstrate the feasibility of production of a reference material that is sufficiently homogeneous and stable with respect to the particle number concentration.Graphical

Adaptative Strategy of Immunosuppressive Drugs Dosage Adjustments When Combined With Nirmatrelvir/Ritonavir in Solid Organ Transplant Recipients With COVID-19.

Nirmatrelvir/ritonavir is a promising option for preventing severe COVID-19 in solid organ transplant recipients with SARS-CoV-2 infection. However, concerns have arisen regarding potential drug interactions with calcineurin inhibitors (CNI). This two-phase multicentre retrospective study, involving 113 patients on tacrolimus and 13 on cyclosporine A, aimed to assess the feasibility and outcomes of recommendations issued by The French societies of transplantation (SFT) and pharmacology (SFPT) for CNI management in this context. The study first evaluated adherence to recommendations, CNI exposure, and clinical outcomes. Notably, 96.5% of patients on tacrolimus adhered to the recommendations, maintaining stable tacrolimus trough concentrations (C0) during nirmatrelvir/ritonavir treatment. After reintroduction, most patients experienced increased C0, with 42.9% surpassing 15ng/mL, including three patients exceeding 40ng/mL. Similar trends were observed in cyclosporine A patients, with no COVID-19-related hospitalizations. Moreover, data from 22 patients were used to refine the reintroduction strategy. Modelling analyses suggested reintroducing tacrolimus at 50% of the initial dose on day 8, and then at 100% from day 9 as the optimal approach. In conclusion, the current strategy effectively maintains consistent tacrolimus exposure during nirmatrelvir/ritonavir treatment, and a stepwise reintroduction of tacrolimus may be better suited to the low CYP3A recovery.

Wild-type lytic bacteriophages against Salmonella Heidelberg: Further characterization and effect of prophylactic therapy in broiler chickens

To characterize wild-type bacteriophages and their effect on Salmonella Heidelberg intestinal colonization in broilers, phages combined in a cocktail were continuously delivered via drinking water since the first day after hatching. After challenge with a field strain, broilers were evaluated at regular intervals for S. Heidelberg and bacteriophages in tissues and cecum, and gross and microscopic lesions in organs. Phages were highly virulent against S. Heidelberg by efficiency of plating. One-step growth curves exhibited eclipse period from 20 to 25 min, whereas the lowest latent period and higher burst size found were 45 min and 54 PFU/cell, respectively. Bacteriophage whole genomic sequencing analyses revealed a lack of genes related to lysogeny, antimicrobial resistance, and virulence factors. Relevant gross or microscopic lesions were absent in tissues analyzed from treated broilers. Although numerically stable bacteriophage concentrations were detected in the cecal contents of treated broilers, no significant difference was found for the S. Heidelberg cecal load in comparison to the untreated group and for the prevalence of positive tissues throughout the evaluated period. The phages produced turbid plaques against some S. Heidelberg re-isolated from treated broilers, suggesting the evolving of a resistant subpopulation. Overall, the results provide new evidence of the safety and in vitro replication of such phages in S. Heidelberg. Nevertheless, continuous administration of the phage suspension most likely induced the development of bacteriophage-resistant mutants, which might have affected the in vivo effect. Therefore, a putative administration protocol should be based on other strategies, such as short-term therapy at pre-harvest age.

Modeling key intermediates during anaerobic digestion of lipid rich kitchen waste with an extended ADM1.

Quantitative dynamics of the key intermediates, gases and carbohydrates during anaerobic digestion of different lipid rich kitchen waste and lipid rich model kitchen waste were modeled. Six batch reactors loaded with 25g l ( 39 l ) kitchen waste and model kitchen waste during a batch experiment were considered in simulation. Observed dynamics of carbohydrates, volatile organic acids and gases were described by an extended benchmark simulation model no. 2 (BSM2). In this study the extended BSM2 included a more detailed -oxidation for prediction of caproic acid. Furthermore, the extensions included carbohydrate digestion with an additional intermediate before propionic acid was released. In addition, a novel simplification approach for initial pH estimation was successfully applied. For parameter estimation a Markov Chain Monte Carlo method was used to obtain parameter distributions. With the presented model it was possible even with no calibrated data to predict point of times of intermediates maxima and propionic acid with relative stable concentration over several days for kitchen waste.

Abstract 2591: Nonclinical ocular toxicity of a maytansinoid payload-antibody drug conjugate: Ocular tissue distribution, lesion pathogenesis, and mitigation

Abstract Background: Antibody-drug conjugates (ADCs) have emerged as a compelling therapeutic modality in oncology with several recent regulatory approvals. However, on and off-target toxicities require further evaluation. Corneal microcyst-like epithelial changes (MECs) are a well-known off-target class effect of ADCs with microtubulin-acting payloads, with varying degrees of severity. Manifestation of MECs is generally unrelated to antibody target and occurs in the absence of corneal target expression. Methods: An ocular toxicology model in Dutch belted rabbits was established using a humanized monoclonal antibody not cross-reactive in rabbits conjugated through an SPDB linker to the maytansinoid drug, DM4. Radiolabeled ADC was administered once and tissues were collected for radioanalysis at multiple time points to evaluate the contribution of ADC exposure and ocular tissue distribution to corneal toxicity. Non-radiolabeled ADC was administered once or twice to evaluate onset and characterization of MECs using slit lamp microscopy and histopathology. Furthermore, potential prophylactic methods for reducing MECs were evaluated. Results: The drug radioactivity was measured over 14 days and was widely distributed with elimination from most ocular tissues (except cornea) similar to blood/plasma elimination (T1/2 of 4.5-7.5 days). In contrast, the corneal layers had an apparent absorption phase followed by a relatively stable concentration plateau through 14 days. Furthermore, preferential distribution to the corneal epithelium was evident by high tissue-to-plasma ratio (1.6 vs <0.5 for other ocular tissues, including other corneal layers). Generally, MECs increased in frequency (number of eyes affected) and decreased in time to onset with increasing dose. Ophthalmic observations of MECs began in the perilimbal cornea with axial migration over time and were reflected by the histopathologic findings in the corneal epithelium of single cell necrosis, increased mitosis, mononuclear cell infiltration, and/or atrophy. A topical ophthalmic vasoconstrictor (brimonidine tartrate 0.2%) delayed the onset of MECs compared to controls (8% vs. 67% of eyes at 7 days; 33% vs. 100% at 10 days) and mitigated severity of some histopathological findings (reduced or absent corneal epithelial atrophy, punctate erosion, pigment, and/or mononuclear cell infiltration). In contrast, corticosteroid administration (prednisolone acetate 1%) did not reduce MECs clinically but did reduce the histologic incidence and severity of corneal pigment and mononuclear cellular infiltration. Conclusion: Collectively, this rabbit model reproduces the MECs associated with maytansinoid ADCs, demonstrates selective long-term corneal epithelium exposure, and provides data to support clinical testing of vasoconstrictor drops as ocular prophylaxis. Citation Format: Ali Warbington, Olga Ab, Sribalaji Lakshmikanthan, Shana Dalton, Paul Miller, Edward Stevens, Patrick Zweidler-McKay, Grace Lytle. Nonclinical ocular toxicity of a maytansinoid payload-antibody drug conjugate: Ocular tissue distribution, lesion pathogenesis, and mitigation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2591.

Effects of high-calorie diet-induced visceral obesity on reproductive hormones and muscle tissues in male and female Wistar rats

Overweight and obesity are associated with alterations in the reproductive system, which affect the anabolic supply to peripheral muscle tissues. The study aimed to investigate the effects of a high-calorie diet (HCD) on the development of obesity, reproductive hormone levels, and morphofunctional characteristics of muscle tissues in Wistar rats (i.e., 54 sexually mature male and female Wistar rats) for 16 weeks. Male rats fed with an HCD displayed (i) visceral obesity and hypogonadism, (ii) a decrease in the mass of the musculus triceps surae, (iii) increased levels of total protein, cholesterol, glucose, lactate, lactate dehydrogenase, and malonic dialdehyde (MDA) and superoxide dismutase (SOD) activities, and (iv) stable concentrations of estradiol and testosterone in the muscle tissues. In contrast, female rats fed with HCD displayed (i) visceral obesity, (ii) alterations in reproductive hormones toward hyperandrogenism, (iii) decreased metabolism in the muscle tissues, and (iv) increased levels of estradiol and MDA (without SOD activation). The cross-sectional area of the muscle fiber was significantly reduced by 20% in male and 44% in female rats on HCD. In addition, the total muscle edema was reportedly increased by twofold in both male and female rats. In summation, obese male and female rats developed an imbalance of reproductive hormones and alterations in muscle tissue metabolism.

Analytical performance specifications based on biological variation data- considerations, strengths and limitations.

Analytical performance specifications (APS) are typically established through one of three models: (i)outcome studies, (ii) biological variation (BV), or (iii) state-of-the-art. Presently, The APS can, for most measurands that have a stable concentration, be based on BV. BV based APS, defined for imprecision, bias, total allowable error and allowable measurement uncertainty, are applied to many different processes in the laboratory. When calculating APS, it is important to consider the different APS formulae, for what setting they are to be applied and if they are suitable for the intended purpose. In this opinion paper, we elucidate the background, limitations, strengths, and potential intended applications of the different BV based APS formulas. When using BV data to set APS, it is important to consider that all formulae are contingent on accurate and relevant BV estimates. During the last decade, efficient procedures have been established to obtain reliable BV estimates that are presented in the EFLM biological variation database. The database publishes detailed BV data for numerous measurands, global BV estimates derived from meta-analysis of quality-assured studies of similar study design and automatic calculation of BV based APS.

Modeling of multi-fractional suspended particle pathways in a shallow water basin under influence of strong winds

In this study, we investigate the complex dynamics of multi-fractional suspended particle transport in a shallow water basin subjected to strong wind conditions. Our research focuses on understanding the interplay between wind-induced advection and particle settlement, and its implications for sediment redistribution.Through our analysis, we reveal the distinct behaviors of different sediment fractions. Clay particles, constituting the lowest fraction in sediment cores, remain suspended throughout the simulation due to their low settlement velocity, with relatively stable concentrations. Conversely, the dominant fraction, medium silt, is suspended during intense wind events but quickly settles to the bed due to its higher settling velocity. Wind stress exceeding 0.05 Pa triggers particulate matter erosion, leading to its presence in the water column.Additionally, we explore the 2D distribution of sediment characteristics, including thickness, dry density, and mud fraction, to identify areas prone to erosion and deposition. Our findings demonstrate that coastal areas of the Taganrog Bay experienced significant erosion following strong wind events, exhibiting the thinnest sediment thickness and the highest dry bulk density. Deposition areas, characterized by thicker sediment layers and lower dry density, were often found in proximity to erosion zones, indicating the influence of particle resuspension and settlement processes.Furthermore, we analyze the implications of our findings on the vulnerability of specific regions to erosion and deposition. The central part of the sea contains moderately thicker sediment layers with a moderately high mud fraction, representing a zone of fine sediment accumulation. These fine sediments, including fine silt and clay, remain suspended for longer durations and are redistributed over greater distances by currents.Overall, our study provides valuable understanding into the multi-fractional suspended particle pathways and their interaction with strong winds in shallow water basins. The results contribute to a better understanding of sediment dynamics, which has implications for coastal management, environmental monitoring, and the preservation of benthic ecosystems.

Tracking the transformation of persistent organic pollutants in food webs using multi element isotope and enantiomer fractionation

In order to track the transformation of persistent organic pollutants (POPs) in food webs, field experiments were conducted at two sites using stable isotope and enantiomer fractionation concepts. The enantiomers of α-hexachlorocyclohexane (α-HCH) were selected as representative compounds for POPs. Isotope and enantiomer fractionation allowed the characterization of α-HCH enantiomer biotransformation processes along trophic levels of the food web - from soil and plants to animal livers, fat tissues and milk. The enrichment of heavy isotopes in soils, plants and sediments as well as the changes of enantiomer fractionation indicate that the biotransformation of α-HCH occurred in these compartments. Moreover, the increase of carbon and chlorine isotopic compositions as well as the changes of enantiomer fractionation of liver, fat tissues and milk demonstrated that the overall HCH exposure was much higher than estimates based on concentration levels, while the isotope and enantiomer fractionation revealed the enantiomer specific enantiomer uptake across the blood-brain barriers. Dual element isotope analysis suggested that complex transformation processes have occurred along the potential food web from the HCH sources over different environmental compartments to animal livers, fat tissues and milk. The results imply that the analyses of stable isotope compositions and concentrations has potential to reconstruct the exposure of higher organisms to POPs.

A comparison between different human hepatocyte models reveals profound differences in net glucose production, lipid composition and metabolism in vitro

Hepatocytes are responsible for maintaining a stable blood glucose concentration during periods of nutrient scarcity. The breakdown of glycogen and de novo synthesis of glucose are crucial metabolic pathways deeply interlinked with lipid metabolism. Alterations in these pathways are often associated with metabolic diseases with serious clinical implications. Studying energy metabolism in human cells is challenging. Primary hepatocytes are still considered the golden standard for in vitro studies and have been instrumental in elucidating key aspects of energy metabolism found in vivo. As a result of several limitations posed by using primary cells, a multitude of alternative hepatocyte cellular models emerged as potential substitutes. Yet, there remains a lack of clarity regarding the precise applications for which these models accurately reflect the metabolic competence of primary hepatocytes. In this study, we compared primary hepatocytes, stem cell-derived hepatocytes, adult donor-derived liver organoids, immortalized Upcyte-hepatocytes and the hepatoma cell line HepG2s in their response to a glucose production challenge. We observed the highest net glucose production in primary hepatocytes, followed by organoids, stem-cell derived hepatocytes, Upcyte-hepatocytes and HepG2s. Glucogenic gene induction was observed in all tested models, as indicated by an increase in G6PC and PCK1 expression. Lipidomic analysis revealed considerable differences across the models, with organoids showing the closest similarity to primary hepatocytes in the common lipidome, comprising 347 lipid species across 19 classes. Changes in lipid profiles as a result of the glucose production challenge showed a variety of, and in some cases opposite, trends when compared to primary hepatocytes.

Long‐term changes in stream water chemistry in small forested watersheds in the northern Kanto region

AbstractConcerns have been raised regarding the degradation of stream water quality due to the excessive influx of atmospheric deposition. This study aimed to reveal the long‐term variation in stream water chemistry in approximately 40 forested small watersheds in the northern Kanto region, based on 3 surveys conducted in 1991–1992, 2006–2007, and 2022. The factors influencing each dissolved element were investigated. Regarding long‐term variations in stream water chemistry, relatively stable concentrations of cations (Ca2+, Mg2+, K+, and Na+) and SiO2 were observed. However, the concentrations of anions (Cl−, , and ) decreased due to the improvement in the atmospheric environment and the diminishing effect of fertilization. Furthermore, the recent increase in stream water pH was attributed to an increase in bicarbonate (), compensating for the decrease in anion concentrations relative to cations. Geology was the most significant factor for inter‐watershed variations in cations and SiO2, and this influence remained relatively constant over 30 years. Forest practices, especially fertilization, had a significant effect on Cl− and , and contributed to higher concentrations in the fertilized watersheds than in the non‐fertilized watersheds over the 15 years following fertilization. Sulfate deposition was a significant influencing factor for , and the concentration fluctuated under long‐term variations in deposition over the past 30 years. Despite substantial acid deposition in the study area, the absence of stream water acidification could be attributed to the abundant cation supply from bedrock and volcanic ash, which underwent weathering processes.

Methane gas sensor based on direct absorption spectroscopy and the laser self-heating effect.

In this paper, a methane detection sensor based on direct absorption spectroscopy and the self-heating effect of lasers is proposed, which abandons the traditional method of relying on a thermoelectric cooler (TEC) to ensure stable gas concentration detection. The sensor can achieve stable concentration measurement in the temperature range of -10∘ to 40°C without the need for a TEC, which greatly simplifies the structure of the sensor and reduces the cost. The results of gas concentration calibration experiments show that the sensor has a good linear correlation (R 2=0.9993). Long-term continuous detection experiments show that the sensor maintains a relative detection error between -2.667% and 4.3% over the full test temperature range. In addition, signal-to-noise ratio analysis experiments further determine that the minimum detection limit of the sensor for methane gas is 27.33p p m⋅m (1σ). Given its advantages of simple structure, low cost, high accuracy, and stability, this methane detection sensor is well suited for natural gas leakage monitoring in home environments and can also be widely used in industrial safety detection and environmental monitoring applications. This technology provides a cost-effective solution for domestic and industrial methane detection.

Microbeads as carriers for Bacillus pumilus: a biofertilizer focus on auxin production

The study aimed to develop a solid biofertilizer using Bacillus pumilus, focusing on auxin production to enhance plant drought tolerance. Methods involved immobilising B. pumilus in alginate-starch beads, focusing on microbial concentration, biopolymer types, and environmental conditions. The optimal formulation showed a diameter of 3.58 mm ± 0.18, a uniform size distribution after 15 h of drying at 30 °C, a stable bacterial concentration (1.99 × 109 CFU g−1 ± 1.03 × 109 over 180 days at room temperature), a high auxin production (748.8 µg g−1 ± 10.3 of IAA in 7 days), and a water retention capacity of 37% ± 4.07. In conclusion, this new formulation of alginate + starch + L-tryptophan + B. pumilus has the potential for use in crops due to its compelling water retention, high viability in storage at room temperature, and high auxin production, which provides commercial advantages.

Recovery of microbial biomass and purification performance after scraping of full-scale slow sand filters

Slow sand filters (SSFs) are widely used in drinking water production to improve microbial safety and biological stability of water. Full-scale SSFs are maintained by scraping the biomass-rich top layers of sand. The period of downtime required for filter recovery after scraping is a major challenge due to limited knowledge of the re-stabilisation of purification processes. This study examined the recovery of microbial biomass, and removal of dissolved organic carbon (DOC) and ammonium (NH4+) in water phase and/or on sand along the depth of a scraped full-scale SSF. Scraping reduced microbial biomass on sand in the top layers, while the main prokaryotic taxa remained unaltered. Cellular ATP (cATP) and intact cell counts (ICC) in water sampled from the top layers increased, indicating a temporary disruption in functionality for 37 days. However, stable concentrations of cATP and ICC and similar microbial community composition in the effluent after scraping revealed that deeper layer biofilms offset any scraping effect. Consistent DOC and NH4+ removal after scraping showed that deeper layers effectively performed the role of the top layer. These findings highlight the resilience and robustness of microbial communities in mature full-scale SSFs and their contribution to water treatment efficiency after disturbances caused by scraping.

An Experimental Investigation of the Effects of Using Hexagonal BN–Water Nanofluids on the Thermal Performance and Pressure Drop of a Concentric Tube Heat Exchanger

The thermal conductivity of recently produced hexagonal boron nitride (hBN)-containing nanofluids is comparatively higher than their viscosity, indicating that these materials belong to a relatively novel class. In this study, hBN–water nanofluids in stable and dispersed concentrations were used in parallel and counterflow experiments at volumes of 0.01%, 0.1%, and 1%, as well as at various flow rates and Reynolds numbers. When employing hBN–water nanofluid in a counter-flow heat exchanger instead of distilled water, the results showed a 16.7% increase in the overall heat transfer coefficient. The findings also showed that, in comparison to a counter-flow heat exchanger, employing hBN nanofluid as the cold fluid in a parallel-flow heat exchanger produced superior results in terms of an increase in heat transfer. The effects of nanofluid concentration on pressure drops were investigated through experiments conducted in both parallel- and counter-flow conditions.

Co-release of paclitaxel and encequidar from amorphous solid dispersions increase oral paclitaxel bioavailability in rats

The oral bioavailability of paclitaxel is limited due to low solubility and high affinity for the P-glycoprotein (P-gp) efflux transporter. Here we hypothesized that maximizing the intestinal paclitaxel levels through apparent solubility enhancement and controlling thesimultaneous release of both paclitaxel and the P-gp inhibitor encequidar from amorphous solid dispersions (ASDs) would increase the oral bioavailability of paclitaxel. ASDs of paclitaxel and encequidar in polyvinylpyrrolidone K30 (PVP-K30), hydroxypropylmethylcellulose 5 (HPMC-5), and hydroxypropylmethylcellulose 4 K (HPMC-4K) were hence prepared by freeze-drying. In vitro dissolution studies showed that both compounds were released fastest from PVP-K30, then from HPMC-5, and slowest from HPMC-4K ASDs. The dissolution of paclitaxel from all polymers resulted in stable concentration levels above the apparent solubility. The pharmacokinetics of paclitaxel after oral administration to male Sprague-Dawley rats was investigated with or without 1 mg/kg encequidar, as amorphous solids or polymer-based ASDs. The bioavailability of paclitaxel increased 3- to 4-fold when administered as polymer-based ASDs relative to solid amorphous paclitaxel. However, when amorphous paclitaxel was co-administered with encequidar, either as an amorphous powder or as a polymer-based ASD, the bioavailability increased 2- to 4-fold, respectively. Interestingly, a noticeable increase in paclitaxel bioavailability of 24-fold was observed when paclitaxel and encequidar were co-administered as HPMC-5-based ASDs. We, therefore, suggest that controlling the dissolution rate of paclitaxel and encequidar in order to obtain simultaneous and timed release from polymer-based ASDs is a strategy to increase oral paclitaxel bioavailability.

Evaluation of UVLED disinfection for biofouling control during distribution of wastewater effluent

Abstract A commercially available UVLED flow-through device, operating at 40 mJ/cm2, was examined for biofilm control on irrigation pipe material fed by wastewater effluent. Biofouling was monitored through total coliform counts, crystal violet (CV) staining, and ATP analyses. A UV fluence of 40 mJ/cm2 at 280 nm retarded biofilm formation; however, complete biofilm prevention by UV treatment was not achieved despite a high inactivation of planktonic cells. After 5 days of the study, the total coliform and CV biofilm quantification assays between the UV-treated and control bioreactor coupons were not statistically different. The total coliform counts indicated a stable biofilm cell concentration was reached; the CV assay showed biofilm biomass accumulation with time. The ATP results revealed higher coupon ATP on the UV-treated coupons than the control coupons by day 5. The results provoke an interesting discussion surrounding the contribution of viable cells, represented by total coliforms, and extracellular polymeric substance (EPS) to total biofilm biomass. This study also highlighted a need for further investigation into the relationship between ATP responses and complex UV-stress responses of diverse microbial communities as opposed to pure bacteria cultures.

Validation of the efficacy of pooled serum for serum glucose inhouse quality control material in comparison with commercial internal quality control in clinical chemistry laboratory

BackgroundThis study aimed to create an in-house glucose quality control material for humans, addressing the challenge of obtaining high-cost commercially prepared quality control materials in developing countries. MethodsAn in-house quality control material for glucose was prepared using a pooled serum sample and analyzed using a fully automated chemistry analyzer following the ISO 80 guidelines. The mean, standard deviation (SD), and coefficient of variance were calculated from the first 30 days of measurement, and the variability was checked over eight months using SPSS software. The study used Pearson's correlation with a 95% confidence interval and a P-value less than 0.05, which was statistically significant. ResultsThe average mean ± SD of human serum glucose was 185.2 ± 8.4 mg/dL, indicating that the precision between each measurement was better. The prepared in-house quality control material was stable for approximately five months without any significant change in the serum glucose concentration (mg/dl) (p-value<0.05). ConclusionsThe study suggests that room-temperature, 2–8 °C, and −20 °C to −30 °C storage of human serum samples for glucose analysis is a viable option, with stable glucose concentrations for up to 30 days. Pooled serum is a cost-effective method for in-house quality control, especially in resource-limited laboratories.

Treatment of greywater with nanofiltration for nutrient removal – 2-year experience from Helsingborg

Abstract Source-separated sanitation and greywater treatment have become an increasingly attractive alternative to traditional wastewater management systems in recent years due to their potential to combat water scarcity, ease resource recovery, and meet tightening effluent demands. In Helsingborg, Sweden, source-separated wastewater from the new city district of Oceanhamnen is being collected and treated in a new treatment plant (RecoLab) to test, among other issues, how efficient greywater treatment can be in achieving low discharge limits for pollutants. The greywater treatment consists of activated sludge treatment, drum filter micro-sieving, and nanofiltration. In the first two years of operation, the robustness of the treatment system during periods with extreme conditions, e.g., very low and very high organic matter concentrations, was tested. The combination of biological treatment and nanofiltration has achieved stable effluent concentrations below 10 mg/L chemical oxygen demand, 2 mg/L total nitrogen, and 0.2 mg/L total phosphorus as average values for 22 months of operation with an average flow of 43 m3/day. The treatment system for greywater treatment thus shows the possibility to achieve low discharge limits and meet the new proposed effluent demands of the EU Urban Wastewater Treatment Directive.