Excretion Rate Research Articles

Design and Experimental Study of Hydrogen Elimination Device for Pd / Pt Exhaust Gas of Proton Exchange Membrane Fuel Cell

This study addresses incomplete hydrogen emissions from hydrogen fuel cell exhausts, focusing on developing safe, efficient strategies to reduce residual hydrogen levels, ensuring compliance with strict environmental and safety norms. Despite maximizing hydrogen utilization, fuel cells inevitably emit residual hydrogen, posing safety risks. An innovative exhaust hydrogen eliminator design is proposed, examining the efficacy of a palladium/platinum catalyst in enhancing hydrogen removal via catalytic combustion. Through systematic investigation on a specialized test platform, factors like airflow, temperature, pressure, and hydrogen concentration influenced the catalytic hydrogen eliminator’s performance. Results highlight the palladium/platinum catalyst’s impact on hydrogen conversion, notably superior platinum performance over palladium, achieving maximum elimination rates of 61% and 96%, respectively. Catalyst shell temperature correlated with input hydrogen concentration, stabilizing near 102°C at 1.97% hydrogen, indicating stable catalytic reactions under tested conditions, pivotal for low-temperature combustion within the hydrogen eliminator.

In Silico Screening of Leguminosae Phytochemicals as Potential Inhibitors of Lung Cancer: A Structure-Based Multi-Targeted Molecular Docking Analysis

About half of the chemotherapeutic drugs are naturally occurring anticancer compounds which are available in the market to date. In silico virtual screening for new anti-cancer drug discovery is a cost-effective method as compared to traditional drug synthesis. From Leguminosae family 144 phytochemicals which were screened from the Dictionary of Natural Products (DNP) undergo molecular docking in comparison to approved drugs Gemcitabine, osimertinib, and Nintedanib against targeted proteins EGFR, BRAF, and KRAS. Only five phytochemicals are 2-Pyrrolecarboxylate, O-(3, 5-Dihydroxy-4-methoxy benzoyl), ?-Aldotripiperideine, O8-(2-Pyrrolecarbonyl), and Benzoyl with high docking scores were selected for further studies based on ADMET lab. In this article, phytochemicals that can inhibit protein growth causing lung cancer were screened and selected by using molecular docking or ADME analysis. In silico ADME studies of these selected phytochemicals suggest that 2-Pyrrolecarboxylate, O-(3,5-Dihydroxy-4-methoxy benzoyl), and O8-(2-Pyrrolecarbonyl) are completely safe, non-toxic, non-carcinogenic, non GERG blocker, do not cause liver injury and have high excretion rate and can be taken for further in vivo and in vitro studies to discover new chemotherapy against lung cancer.

In vivo Assessment of Diltiazem HCl Immobilized Co-polymeric pH Sensitive Microgels

Novel stimuli responsive coplymeric (2-ethyl hexyl acrylate -co- itaconic acid diltiazem HCl loaded microgels were fabricated and characterized successfully to reduce the degradation of drugs in acidic pH of stomach resulting in reduced bioavailability to minimize dosing frequency and enhance patient compliance. To evaluate the clinical significance, in-vivo studies of recently prepared novel pH sensitive copolymeric microgels are performed and different pharmacokinetic parameters as maximum plasma concentration (Cmax), time to reach the maximum plasma concentration (Tmax), area under the plasma concentration-time curve (AUC 0-?), half-life (t 1/2?) and elimination rate constant (K21) are analyzed. The mean plasma concentration of sustained release DLZ loaded microgels showed higher Tmax for prepared microgels (4.0758±0.22 hrs) than standard drug solution. The half-life t1/2? of test microgels is relatively higher (5.68±5.86 hrs) whereas the Cmax is measured to be 41.06±2.02ng/ml for microgels with AUC0-? calculated as 460.35±39.99 ng.hr/ml. Elimination rate constant K21 for DLZ microgels is 0.18 ± 0.07 hrs-1 for which showed the absorption phase is extended and drug is present for a prolong period of time in the body. This study proved that novel prepared pH sensitive copolymeric p(EHA-co-IA) microgels released model drug in sustained release manner in pH sensitive medium.

KIDNEYS INVOLVEMENT INTO THE THYROID GLAND BURNING PATHOGENETIC MECHANISMS

Background. Burn injuries considered to be the most common and severe diseases in people, positioned second place after traffic injuries. The thyroid gland, taking into account the wide range of thyroid hormones physiological activity, its structural and functional organization and morpho-functional features as well as large-scale duplicative mechanisms of regulatory feedback, is one of the first which receives the alterative thermal influence. Thyroid gland and other organs of the body dysfunction or pathological dysregulation occurs as a result of thermal exposure “triggers” systemic dysfunctions via the “vicious circle” and positive feedback mechanisms and systemic-antisystemic regulation which cannot be ignored by the majority of internal organs and organ systems resulting ion their functional disorders. We decided to test the assumptions regarding the kidneys participation in thyroid burning pathological process manifestation.
 Aim: to investigate the changes in lipid peroxidation and antioxidant defense in erythrocytes and kidney tissue and to investigate the kidneys functional activity throughout the thyroid gland thermal.
 Materials and methods. The malondialdehyde concentration and antioxidant enzymes activity - glutathione, catalase, superoxide dismutase and glutathione peroxidase - were determined in white Wistar rats’ erythrocytes and kidney homogenate 1, 3, 7, 14, 21, and 30 days after the thyroid gland burning. Diuresis was calculated in rats during induced water diuresis and both the protein and creatinine content in urine was determined during the indicated periods after thyroid gland burning
 Results. The significant accumulation of lipoperoxidation intermediate products and the antioxidant enzymes activity suppression in erythrocytes and in the kidney parenchyma are registered in rats during the post-burn period. The postburn period course is characterized by diuresis decrease. The urine protein level increased and the rate of protein excretion also increased in conditions of thyroid gland burning
 Conclusion. Significant accumulation of lipoperoxidation intermediate products and the antioxidant enzymes activity suppression in erythrocytes and in the liver parenchyma is recorded in thyroid gland burning dynamics which we consider as evidence of erythrocytes and kidney involvement in the specified pathological process mediation. The expressed renal dysfunction develops with thyroid gland thermal damage which is manifested by kidneys both excretory and filtering functions impairment. The data obtained we consider as the experimental background for kidney involvement into the thyroid gland burning pathogenetic mechanisms and the pathological dysregulation of organs and organ systems formation in these pathological conditions.

Isopod mouthpart traits respond to a tropical forest recovery gradient.

Functional trait ecology has the potential to provide generalizable and mechanistic predictions of ecosystem function from data of species distributions and traits. The traits that are selected should both respond to environmental factors and influence ecosystem functioning. Invertebrate mouthpart traits fulfill these criteria, but are seldom collected, lack standardized measurement protocols, and have infrequently been investigated in response to environmental factors. We surveyed isopod species that consume plant detritus, and tree communities in 58 plots across primary and secondary forests in Singapore. We measured body dimensions (body size traits), pereopod and antennae lengths (locomotory traits), dimensions of mandible structures (morphological mouthpart traits), and mechanical advantages generated by mandible shape (mechanical mouthpart traits) for six isopod species found in these plots and investigated if these traits respond to changes in tree community composition, tree diversity, and forest structure. Morphological mouthpart traits responded to a tree compositional gradient reflecting forest recovery degree. Mouthpart features associated with greater consumption of litter (broader but less serrated/rugose lacinia mobilis [an important cutting and chewing structure on the mandible]) were most prevalent in abandoned plantation and young secondary forests containing disturbance-associated tree species. Feeding strategies associated with fungi grazing (narrower and more serrated/rugose lacinia mobilis) were most prevalent in late secondary forests containing later successional tree species. Since morphological mouthpart traits likely also predict consumption and excretion rates of isopods, these traits advance our understanding of environment-trait-ecosystem functioning relationships across contrasting tropical forest plots that vary in composition, disturbance history, and post-disturbance recovery.

Applicable Pharmacokinetic Study: Development and Validation of Bioanalytical LC-MS/MS Method for Simultaneous Determination of Tipiracil, Trifluridine and Its Two Metabolites 5-Trifluoromethyluracil, 5-Carboxy 2′-Deoxyuridine in Rat Plasma

A novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous determination of tipiracil (TIP), trifluridine (FTD), and their metabolites, 5-trifluoromethyluracil (FTY) and 5-carboxy-2′-deoxyuridine (5CDU), in rat plasma. This method is highly sensitive, specific, and fast. Paracetamol (PAR) is used as an internal standard (IS). Using acetonitrile-induced protein precipitation, the analytes were extracted from a plasma sample and separated on a Waters BEH C18 (1.7 μm particle size, 50 mm × 2.1 mm ID) column protected by a security guard cartridge (C18, 4 × 2.0 mm). The isocratic mobile phase was made up of methanol and water containing 0.1% formic acid (80:20, v/v) at a flow rate of 0.5 mL/min for 4 min. The quantification was performed using a positive electrospray ionization (ESI) interface and a multiple-reaction monitoring (MRM) mode. The MRM transitions employed were m/z 242.96 → 182.88 for TIP, 296.96 → 116.86 for FTD, 180.98 → 139.85 for FTY, 272.96 → 156.86 for 5CDU, and 151.97 → 92.68 for IS. The validated method complied with the guidelines set by the US-FDA over on a linear concentration range of 5–4000 ng/mL for FTD, FTY, and 5CDU, and 5–1000 ng/mL for TIP. The coefficient of determination (r2) was equal to or greater than 0.997. The corresponding lower limits of detection (LLOD) were 1.5 ng/mL for FTD, FTY, and 5CDU and 1.0 ng/mL for TIP. The recoveries of all analytes from rat plasma ranged from 88.67% to 112.18%, and the mean relative standard deviation (RSD) of accuracy and precision result was less than or equal to 6.84%. FTD, FTY, 5CDU, and TIP demonstrated adequate stability throughout the various circumstances examined. Additionally, no matrix effects were identified for any of the analytes. The assay was effectively utilized to conduct a pharmacokinetic study in rats following the oral administration of FTD and TIP at a dosage of 5.6 mg/kg, with a ratio of 1:0.5 for FTD and TIP, respectively. This indicates that the suggested approach is suitable for future clinical research. The pharmacokinetic parameters Cmax (maximum concentration), Tmax (time to reach maximum concentration), t1/2 (half-life), AUC0-24 (area under the concentration–time curve from 0 to 24 h), AUC total (total area under the concentration–time curve), Ke (elimination rate constant), Vd (volume of distribution), and CL (clearance) of all analytes were assessed. The assay developed exhibits significant advancements compared to earlier bioanalytical methods documented in the literature. These improvements include high sensitivity, specificity, and efficacy in high throughput analysis of complex matrices. Additionally, the assay offers a shorter run time and smaller sample volume (50 μL).

Indexes of ferroptosis and iron metabolism were associated with the severity of diabetic nephropathy in patients with type 2 diabetes mellitus: a cross-sectional study.

To explore the correlations between diabetic nephropathy (DN) and serum levels of glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4), iron, transferrin (Tf), and ferritin in patients with type 2 diabetes mellitus (T2DM). According to the urinary albumin excretion rate(UAER) or estimated glomerular filtration rate (eGFR) levels, a total of 123 patients with T2DM were separately divided into normoalbuminuria (NO), microalbuminuria (MI), macroalbuminuria (MA) groups, and G1 (eGFR ≥ 90 mL/min), G2 (eGFR ≤ 60 mL/min to < 90 mL/min), and G3 groups (eGFR< 60 mL/min), with 33 healthy participants as the control (HC). The differences in serum GPX4, ACSL4, iron, Tf, and ferritin levels between groups were compared, and the relationships between these levels were analysed. The independent correlations between UAER or DN severity and serum GPX4, ACSL4, iron, Tf, and ferritin levels were analysed by multiple linear and multinomial logistic regression, respectively. To the patients with T2DM, with the increase in UAER levels, GPX4, iron, and Tf levels gradually decreased, whereas ACSL4 levels increased, meanwhile with the decrease in eGFR levels, GPX4 and Tf levels gradually decreased, whereas ACSL4 levels increased. UAER were independently and positively correlated with ACSL4 [β = 17.53, 95% confidence interval (CI; 11.94, 23.13)] and negatively correlated with GPX4 [β = -1.633, 95% CI (-2.77, -0.496)] and Tf [β = -52.94, 95% CI (-95.78, -10.11)].The NO and MI groups were considered as reference groups, respectively. The severity of DN was negatively correlated with serum GPX4 [odds ratio (OR) = 0.925 and 0.902, p =0.015 and 0.001], and Tf (OR = 0.109 and 0.119, p =0.043 and 0.034), and positively correlated with ACSL4 (OR = 1.952 and 1.865, both p <0.001) in the MA group. DN severity was negatively correlated with serum GPX4 and Tf levels and positively correlated with serum ACSL4 levels in patients with T2DM.

Comparison on removal performance of virus, antibiotic-resistant bacteria, cell-associated and cell-free antibiotic resistance genes, and indicator chemicals by ozone in the filtrated secondary effluent of a sewage treatment plant

Due to the widespread appearance of viruses, antibiotic-resistant bacteria (ARBs), and antibiotic resistance genes (ARGs) in the aquatic environment, more powerful oxidation processes such as ozonation are needed to enhance the efficiency of their inactivation and removal during wastewater treatment. However, information is lacking on the elimination rates of viruses, ARBs, cell-associated ARGs (ca-ARGs), and cell-free ARGs (cf-ARGs) during ozonation. This study examined the kinetics and dose-dependent inactivation of a virus (MS2 coliphage) and an ARB (Ampicillin-resistant [AmpR] E. coli) and the removal of ca- and cf-ARGs (plasmid-encoded blaTEM) by ozonation in a filtered secondary effluent (SE) of a municipal sewage treatment plant (STP). In addition, the ozonation kinetics of carbamazepine (CBZ) and metoprolol (MTP)—ubiquitous organic micropollutants with different removal rate constants—were also investigated in order to monitor their effectiveness as indicators for the abovementioned biological risk factors. Our results showed that ozonation was an efficient way to remove MS2, AmpRE. coli, ARGs, CBZ, and MTP. We investigated the kinetics of their inactivation/removal with respect to exposure in terms of CT (dissolved ozone concentration C and contact time T) value, and found their inactivation/removal constants were in the following order: MS2 (8.66 ×103 M−1s−1) ≈ AmpRE. coli (8.19 ×103 M−1s−1) > cf-ARG (3.95 ×103 M−1s−1) > CBZ (3.21 ×103 M−1s−1) > ca-ARG (2.48×103 M−1s−1) > MTP (8.35 ×102 M−1s−1). In terms of specific ozone dose, > 5-log inactivation of MS2 was observed at > 0.30 mg O3/mg DOC, while > 5-log inactivation of AmpRE. coli was confirmed at 1.61–2.35 mg O3/mg DOC. Moreover, there was almost no removal of ca-ARG when the specific ozone dose was < 0.68 mg O3/mg DOC. However, 2.86–3.42-log removal of ca-ARG was observed at 1.27–1.31 mg O3/mg DOC, while 1.14–1.36-log removal of cf-ARG was confirmed at 3.60–4.30 mg O3/mg DOC. As alternative indicators, > 4-log removal of CBZ was observed at > 1.00 mg O3/mg DOC, while > 2-log removal of MTP was confirmed at > 2.00 mg O3/mg DOC. Thus, it was observed that inactivation of E. coli needs a greater ozone dose to achieve the same level of inactivation of AmpRE. coli; for ARGs, cf-ARG can persist longer than ca-ARG if low dosages of ozone are applied in the filtrated SE, CBZ might act as an indicator with which to monitor the inactivation of viruses and ARBs, while MTP might act as an indicator with which to monitor removal of ARGs. Moreover, cf-ARG cannot be neglected even after ozonation due to the possibility that ca-ARGs can become cf-ARGs during ozonation and be discharged with the final effluent, posing a potential risk to the receiving environment.

Transcutaneous Electrical Acustimulation Improves Constipation Symptoms and Accelerates Colonic Transit in Patients With Slow Transit Constipation Through Autonomic Mechanism

ObjectivesNearly half of patients with slow transit constipation (STC) are not completely satisfied with their traditional remedies. We aimed to evaluate the therapeutic value and possible involved mechanism of transcutaneous electrical acustimulation (TEA) at ST36 in patients with STC. Materials and MethodsSeventy patients with STC were randomly divided into TEA (n = 35) and sham-TEA (n = 35) to undergo a two-week treatment with TEA at ST36 or sham point. After the two-week treatment, 18 patients from each group randomly underwent a few physiological tests, including the electrocardiogram (ECG), anorectal manometry, colon transit test, and blood drawing. After a two-week washout period, TEA was performed in both groups for two weeks. ResultsSpontaneous bowel movements per week were increased, and scores of constipation symptoms were decreased, after a two-week blind TEA but not sham-TEA, which were sustained after a two-week washout period. Improvement in quality of life and psychologic states also was observed with blind TEA treatment. Mechanistically, the two-week blind TEA accelerated colon transit assessed by barium strip excretion rate (the effect was sustained after a two-week washout period), enhanced vagal nerve activity evaluated by the spectral analysis of heart rate variability derived from the ECG, and decreased circulating vasoactive intestinal peptide. ConclusionsNoninvasive TEA relieves constipation and improves quality of life and psychologic states in patients with STC, and the effects are sustained for ≥two weeks. The therapeutic effects of TEA may be attributed to the acceleration of colon transit and decrease of vasoactive intestinal peptide mediated through the vagal mechanism.

Delineating endogenous Cushing’s syndrome by GC-MS urinary steroid metabotyping

BackgroundDiagnosing Cushing’s syndrome (CS) is highly complex. As the diagnostic potential of urinary steroid metabolome analysis by gas chromatography-mass spectrometry (GC-MS) in combination with systems biology has not yet been fully exploited, we studied a large cohort of patients with CS. MethodsWe quantified daily urinary excretion rates of 36 steroid hormone metabolites. Applying cluster analysis, we investigated a control group and 168 patients: 44 with Cushing’s disease (CD) (70% female), 18 with unilateral cortisol-producing adrenal adenoma (83% female), 13 with primary bilateral macronodular adrenal hyperplasia (PBMAH) (77% female), and 93 ruled-out CS (73% female). FindingsCluster-Analysis delineated five urinary steroid metabotypes in CS. Metabotypes 1, 2 and 3 revealing average levels of cortisol and adrenal androgen metabolites included patients with exclusion of CS or and healthy controls. Metabotype 4 reflecting moderately elevated cortisol metabolites but decreased DHEA metabolites characterized the patients with unilateral adrenal CS and PBMAH. Metabotype 5 showing strong increases both in cortisol and DHEA metabolites, as well as overloaded enzymes of cortisol inactivation, was characteristic of CD patients. 11-oxygenated androgens were elevated in all patients with CS. The biomarkers THS, F, THF/THE, and (An + Et)/(11β-OH-An + 11β-OH-Et) correctly classified 97% of patients with CS and 95% of those without CS. An inverse relationship between 11-deoxygenated and 11-oxygenated androgens was typical for the ACTH independent (adrenal) forms of CS with an accuracy of 95%. InterpretationGC-MS based urinary steroid metabotyping allows excellent identification of patients with endogenous CS and differentiation of its subtypes. FundingThe study was funded by the Else-Kröner-Fresenius-Stiftung and the Eva-Luise-und-Horst-Köhler-Stiftung.

Population Pharmacokinetic Modeling for Twice-Daily Intravenous Busulfan in a Large Cohort of Pediatric Patients Undergoing Hematopoietic Stem Cell Transplantation-A 10-Year Single-Center Experience.

Reaching target exposure of busulfan-based conditioning prior to hematopoietic stem cell transplantation is vital for favorable therapy outcomes. Yet, a wide inter-patient and inter-occasion variability in busulfan exposure has been reported, especially in children. We aimed to identify factors associated with the variability of busulfan pharmacokinetics in 124 consecutive patients transplanted at the University Children's Hospital Zurich between October 2010 and February 2020. Clinical data and busulfan plasma levels after twice-daily intravenous administration were analyzed retrospectively by population pharmacokinetic modeling. The volume of distribution correlated with total body water. The elimination rate constant followed an age-dependent maturation function, as previously suggested, and correlated with the levels of serum albumin. Acute lymphoblastic leukemia reduced busulfan clearance by 20%. Clearance significantly decreased by 17% on average from the start to the third day of busulfan administration, in agreement with other studies. An average reduction of 31% was found in patients with hemophagocytic lymphohistiocytosis and X-linked lymphoproliferative disease. In conclusion, we demonstrate that in addition to known factors, underlying disease and serum albumin significantly impact busulfan pharmacokinetics in pediatric patients; yet, substantial unexplained variability in some patients remained. Thus, we consider repeated pharmacokinetic assessment essential to achieve the desired target exposure in twice-daily busulfan administration.

A FRACTIONAL DIFFERENTIAL EQUATION MODEL FOR THE SPREAD OF POTATO LEAF ROLL VIRUS (PLRV) ON POTATOES

Potatoes infected with the PLRV virus will experience a decrease in production up to 90%. In this paper, The PLRV distribution fractional differential equation model with potato and vector populations is reformulated by adding one new parameter, namely the rate of vector death due to predators. The model is divided into susceptible and infected classes. The PLRV dispersion model was developed and converted to a fractional order form for 0&lt;σ ≤ 1. Next, the invariant region, positive solutions, basic reproduction number, equilibrium point, and stability were determined. Based on the stability analysis, it is shown that the stability of the disease-free equilibrium point is locally stable and globally stable if the basic reproduction number (R0)&lt;1, and the stability of the endemic equilibrium point is globally stable if the basic reproduction number (R0)&gt;1. Numerical solutions were also carried out to determine the effect of several parameters on the PLRV distribution model on potatoes. The numerical solution results show that the elimination rate of infected potatoes and the infection rate of potatoes have a significant role in controlling the spread of PLRV in potatoes.

IMMUNOSTIMULANT ACTIVITY OF HANTAP (STERCULIA COCCINEA JACK) LEAVES EXTRACT ON NON-SPECIFIC AND SPESIFIC IMMUNE RESPONSES

Objective: This study aims to determine the immunostimulant effect and the effective dose of hantap leaf ethanolic extract against non-specific and specific immune responses.&#x0D; Methods: The immunostimulant activity of the extract was tested by the carbon clearance method (non-specific response). The effect of the extract on delay-type hypersensitivity/DTH (cellular-specific response) was determined by the paw edema method. The number of leukocyte cells and the percentage of leukocyte cell types were also calculated. The antibody titer (humoral-specific response) test was carried out by the hemagglutination method.&#x0D; Results: The results of the non-specific immune response demonstrated that three doses of hantap leaf extract, when compared to the negative control, could accelerate the rate of carbon elimination and increase the phagocytosis index. Hantap leaf extract can provide an immunomodulatory effect by increasing the delayed-type hypersensitivity response by showing a greater volume of leg swelling than the negative control received CMC Na 0.5%, which was significantly different (p&lt;0.05), increasing leukocyte count and leukocyte differential and increasing primary and secondary antibody titers. The effective dose of hantap leaves extract was 200 mg/kg body weight.&#x0D; Conclusion: This study proves that hantap leaf extract has an immunomodulatory effect that increases the immune system (immunostimulant)

Nitrogen excretion by the lobsters Panulirus ornatus and Thenus australiensis and uptake by the brown algae Sargassum siliquosum: Implications for integrated recirculated aquaculture systems

Farming extractive species such as macroalgae that take up nitrogen (N), with fed species (e.g., lobsters, finfish, prawns) is termed integrated multi-trophic aquaculture (IMTA). In recirculating aquaculture systems (RAS), high concentrations of nitrogenous waste can become toxic to the fed species and macroalgae offers a method of mitigating N waste. To utilise macroalgae as a biofilter for N waste, an understanding of their N ecophysiology of both the fed and extractive species is needed. In this study we first determine the ammonium and urea excretion rates for emerging aquaculture candidates the tropical rock lobsters, Panulirus ornatus (TRL) and slipper lobster, Thenus australiensis (SL). Using multiple flask uptake experiments, we then determined the N ecophysiology of the tropical brown macroalga, Sargassum siliquosum, to assess its potential use as a biofilter in a lobster RAS. Routine (basal) N excretion was predominantly ammonium with only a minor contribution of urea (8 and 13% for TRL and SL respectively). For both lobster species, ammonium and urea excretion substantially increased post-prandial, peaking at levels 3.6 times greater than basal amounts for TRL and 3.2 times greater for SL, and remained elevated for between 32 and 38 h. Uptake of both ammonium and nitrate by S. siliquosum showed saturating kinetics, where the kinetic parameter Vmax is the maximum rate of uptake, Ks is the half-saturation constant and the Vmax:Ks-ratio is a proxy for the algae's affinity of uptake for that respective nutrient: for ammonium Vmax = 110.9 μmoles g−1 dry weight (DW) h−1 and Ks = 37.9 μM and for nitrate Vmax = 152.7 μmoles g−1 DW h−1 and Ks = 58.52 μM. Urea uptake was highly variable with both positive and negative (i.e. urea release from tissue) rates recorded; when positive values were considered, Vmax = 55.5 μmoles g−1 DW h−1 and Ks = 17.65 μM. We used uptake and excretion rates from our study to derive a unit mass stocking ratio of algae to lobster (algae: animal) to offset N pollution in RAS. The ratios of TRL to algae to offset NH4+ and urea post-prandial were 5.15E-04 and 3.09E-04 respectively and for SL, 4.46E-04 and 6.31E-04 respectively. The findings serve as a reference for future studies on integrating Sargassum species into RAS and IMTA systems.

Retention and excretion of microplastics by Yellow Mealworm (Tenebrio molitor) larvae reared on an amino formaldehyde polymer microbeads contaminated substrate

Abstract Yellow mealworm (Tenebrio molitor L., TM), one of the main cultured insect species, is used for feed and food. Larval stages of this species can be reared on several substrates, including grains and industrial by-products. However, this species may potentially accumulate contaminants from the substrate, including microplastics (MPs), which may represent a potential hazard for its utilization in food chain. Evidences for plastic degradation by mealworms have been reported, while there are few information about the retention of microplastics in the body and tissues of this species. The aim of the present study was to assess whether TM larvae reared on a MPs-contaminated substrate were able to retain MPs in body tissues and to evaluate the retention and excretion rate after fasting for 24 and 48 hours. For this purpose, fluorescent amino formaldehyde polymer microbeads (1-5 μm) were used to simulate a MPs contamination in the substrate used for larvae rearing. A relevant concentration of MPs were found in the gut and were associated with ingested feed. However, microscopic analyses indicated that the gut acts as a simple transit site and a barrier towards MPs migration in tissues. A marked reduction of MPS content was highlighted in larvae after fasting, even though a 48-hours fasting period was not sufficient to completely depurate insect gut from MPs. Results obtained in the present study suggest that the polymer microbeads used are recalcitrant to digestion by TM larvae, and show the relevant ability of depuration from MPs of this species. Taken together the results showed the suitability of TM to be reared on MPs contaminated substrates since larvae survival and growth resulted not hampered by the MPs presence and open cues on the fasting period able to completely depurate insect body from MPs residues.

Preparation and Antimicrobial Activity of a Film-Forming Polyhexamethylene Biguanide Teat Disinfectant.

Bovine mastitis caused by infectious pathogens can lead to a decline in production performance and an increase in elimination rate, resulting in huge losses to the dairy industry. This study aims to prepare a novel dairy cow teat disinfectant with polyhexamethylene biguanide (PHMB) as the main bactericidal component and to evaluate its bactericidal activity in vitro and its disinfection effect in dairy cow teats. PHMB disinfectant with a concentration of 3 g/L was prepared with PVA-1788, propylene glycol and glycerol as excipients. When the dilution ratio is 1:4800 and the action time is 5 min, the PHMB teat disinfectant can reduce the four types of bacteria (S. agalactiae ATCC 12386, S. dysgalactiae ATCC 35666, S. aureus ATCC 6538, and E. coli ATCC 8099) by 99.99%. PHMB teat disinfectant applied on the skin of rabbits with four bacteria types achieved an average log10 reduction greater than 4. After 30 s of PHMB teat disinfectant dipping, the bacteria of cow teats were counted prior to disinfection. The mean log10 reduction in bacteria on the skin surface of 12 cows ranged from 0.99 to 3.52 after applying the PHMB teat disinfectant for 10 min. After 12 h, the PHMB teat disinfectant achieved an average log10 reduction in bacteria from 0.27 to 0.68 (compared with that prior to disinfection). These results suggested that PHMB teat disinfection has the potential to prevent and treat mastitis-causing bacteria in dairy herds.

Improved quantitative determination of (R)- and (S)‐rabeprazole sodium and its metabolites in rat plasma by LC-MS/MS and its application to a toxicokinetic study

There exist two enantiomers: (R)‐ and (S)‐rabeprazole. (R)‐rabeprazole offers specific pharmacokinetic advantages and enhanced therapeutic efficacy, warranting further investigation and development. Here, we developed a simple and rapid chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to simultaneously quantify rabeprazole enantiomers and their metabolites (rabeprazole sulfoxide and desmethyl rabeprazole enantiomers) and a LC-MS to quantify rabeprazole thioether. As for the chiral LC-MS/MS method, Chiral-AGP column (150 × 4 mm, 5 μm) was used and its mobile phase was acetonitrile (mobile phase A) and 10 mmol/L ammonium acetate (mobile phase B) (linear gradient profile: 0 min, 10 % B; 5 min, 15 % B; 9 min, 15 % B; 9.01 min, 10 % B; 13 min, 10 % B). The multiple reactions monitoring transitions of m/z 360.3 → 242.1, 376.2 → 240.1, 346.2 → 228.2 and 368.2 → 190.2 were opted for quantifying rabeprazole enantiomers, rabeprazole sulfoxide, desmethyl rabeprazole enantiomers and internal standard omeprazole. The analyte samples were prepared by a simple liquid–liquid extraction method. As for the LC-MS method, analytes were separated on a Inertsil® ODS-3 column (4.6 × 150 mm, 5 μm). The mobile phase was acetonitrile-5 mmol/L ammonium acetate water solution (65:35, v/v). ESI+ was used and ion peaks with m/z 344.2 (rabeprazole thioether) and 285.1 (internal standard diazepam) were monitored. Both these 2 methods were validated for specificity, linearity, precision, accuracy, matrix effect and extraction recovery, and, particularly, the stability of analytes under various conditions. We successfully applied these methods to a 13-week toxicokinetic study of rabeprazole in rats after intravenous administration of (R)- (80, 20, 5 mg/kg/d) and racemic (80 mg/kg/d) rabeprazole sodium. The results showed that rabeprazole and its metabolites did not accumulate in rats. However, desmethyl rabeprazole and rabeprazole thioether showed higher exposure and lower clearance rate in the last administration than in the first one. (R)-rabeprazole showed a higher exposure and a slower elimination rate than (S)-rabeprazole in rats. These findings offer experimental evidence and a theoretical foundation for further preclinical investigations and clinical applications of (R)-rabeprazole.

Study on the dominant mechanism of direct hole oxidation for the photodegradation of tetracycline.

Antibiotic contamination has a significant negative impact on China, one of the largest producers and consumers of antibiotics worldwide. In this study, a three-dimensional flower-like structure of CoFe-LDHs was used to efficiently degrade tetracycline (TC) in a system triggered by peroxymonosulfate (PMS) and exposed to visible light. After exploring the effects of different metal ratios, catalyst dosage, initial TC concentrations, and pH, the optimal reaction conditions were determined. In comparison to pure CoFe-LDHs, the TC elimination rate was dramatically increased by the addition of the PMS. The strong environmental resistance, excellent stability and reusability, and universal flexibility were shown. The quenching experiments and electron spin resonance detection showed that the creation of reactive oxygen species was facilitated by the synergistic transmission of electrons between the active bimetallic components. Further, photogenerated holes was the dominant oxidizing species, which contributed more to the degradation of TC. The potential degradation pathways and intermediate toxicity of TC were suggested. This work offers a new method dominated by photogenerated holes for efficiently removing TC effluent.

Relationship between stable cesium concentration and body size of Japanese flounder Paralichthys olivaceus and the effect of a size-dependent shift in diet.

To understand the relationship between the radioactive cesium (Cs) concentration in muscle of Japanese flounder Paralichthys olivaceus and the species' biological characteristics (size, sex, and age) under conditions of ecological equilibrium (i.e., distributed among ecosystem components over sufficient time, and with nearly constant ratios of Cs concentration in organisms to the concentration in water) as existed before the accident at the Fukushima Dai-ichi Nuclear Power Station (FDNPS), Japan, in 2011, we examined stable Cs, as it is thought to exist in equilibrium in the environment and behave similarly to radioactive Cs in aquatic animals. The concentration of stable Cs in 241 P. olivaceus (range 216-782 mm total length [TL]) collected in Sendai Bay, approximately 90 km north of the FDNPS, in June-July 2015 was expressed as an exponential function with size as an independent variable; the results show the concentration of stable Cs doubled with an increase in TL of 442 mm. Next, to evaluate the cause of the size-dependent change in stable Cs concentration, we examined 909 individuals (200-770 mm TL) collected in September 2013-July 2015 to determine their feeding habit based on size. Analysis of the frequency of occurrence of prey organisms in stomach contents showed that sand lance Ammodytes japonicus (55-180 mm standard length [SL]) was the most consistently consumed across size classes. Analysis on a wet-mass basis showed that A. japonicus and anchovy Engraulis japonicus (65-130 mm SL) were the main food of P. olivaceus sized 200-599 mm TL, whereas chub mackerel Scomber japonicus (120-230 mm SL) and two species of flatfishes (180-205 mm SL) were abundant in the diet of P. olivaceus sized ≥600 mm TL. All these prey items were presumed to have similar concentrations of stable Cs. Based on the above, the effect of diet on the relationship between stable Cs in muscle and fish size was considered negligible. That the diet of P. olivaceus largely did not change with size was also confirmed by C and N stable isotope ratios in P. olivaceus and their prey species. Therefore, the Cs-size relationship is probably determined by changes in the balance between the rate of Cs intake from food and seawater and the excretion rate during growth, both of which change as functions of body mass. Values of stable Cs concentrations among environmental components and animals appear to be a valid indicator for understanding the radioactive Cs distribution in the marine environment and aquatic animals under the equilibrium state, as existed before the 2011 nuclear accident.

Use of oak acorns adsorbent and response surface methodology for removal of crystal violet from aqueous solution

ABSTRACTThis study investigates the potential use of oak acorn pericarp powder as an effective adsorbent for removing crystal violet from aqueous solutions under citric acid activation. Various analytical techniques, including FTIR, EDS, and SEM, were used to examine the characteristics of the adsorbent obtained. Throughout the experiments, parameters such as adsorbent quantity, solution pH, and initial dye concentration were meticulously taken into account. To optimise this removal process, a customised experimental approach based on response surface methodology (RSM) was adopted, involving the performance of 20 series of experiments to assess the influence of key variables, including adsorbent dose (A), pH (B), and initial dye concentration (C), as well as their interactions. Statistical analysis reveals the high significance of the elimination model, supported by an extremely low probability value (p < 0.0001). Notably, increasing adsorbent mass and solution pH leads to higher rates of crystal violet removal. Conversely, as the initial dye concentration increases, the removal rate decreases. Furthermore, the interaction between these variables does not appear to have a significant influence. Under optimal conditions, a remarkable elimination rate of 99.96% was achieved. This involved a solution with an initial pH of 10.82, an adsorbent dose of 28.5 mg, and an initial dye concentration of 17.8 mg/L. The kinetics of crystal violet adsorption onto the adsorbent were effectively described by a pseudo-second-order equation. Additionally, the optimal multilayer uptake capacity of OA@CA for CV dye was determined to be 135.9 mg.g−1, and the Freundlich model demonstrated a significantly better fit to the experimental results when compared to the Langmuir model.