Short-term Experiments Research Articles

Glyphosate Effects on Some Characteristics of Biological Activity and Phytotoxicity of Sod-Podzolic Soil in a Short-Term Model Experiment

In a model laboratory experiment on infertile arable soil with low biological activity, it was found that the introduction of glyphosate leads to a short-term change in the intensity of the main processes of microbial transformation of nitrogen in the soil. When incubating soil with glyphosate at the maximum recommended dose of 8 l/ha for 22 days, there is an increase in nitrogen-fixing and denitrifying activity by 30–80% and 300% and a decrease in the nitrification process by 20–40%. The effects are of a short-term nature and do not reflect the entire complex of ongoing microbiological processes: no effect of glyphosate was detected on the emission of CO2, which is an integral indicator of biological activity. At the end of incubation in the soil with the introduced glyphosate, there was an increase in the number of bacteria by 40% and a decrease in the number of micromycetes by 70%. In general, under the selected conditions, the introduction of glyphosate led to a marked deterioration in the biological activity of the soil. By the method of multisubstrate testing, it was shown that under the action of the herbicide there is an increase in the value of the coefficient of rank diversity of the consumption spectra of substrates d, accompanied by a decrease in the specific metabolic work W and the integral vitality index G. It was shown for the first time that when glyphosate is introduced into soil with low biological activity and availability of phosphorus and the herbicide is degraded along the sarcosine pathway with a break in the C–P bond, excluding the formation of toxic metabolites, there is a pronounced negative effect of glyphosate on soil microorganisms, which leads to inhibition of wheat plant growth.

Invasive frogs show persistent physiological differences to elevation and acclimate to colder temperatures

The coqui frog (Eleutherodactylus coqui) was introduced to the island of Hawai'i in the 1980s and has spread across much of the island. Concern remains that this frog will continue to expand its range and invade higher elevation habitats where much of the island's endemic species are found. We determined whether coqui thermal tolerance and physiology change along Hawai'i’s elevational gradients. We measured physiological responses using a short-term experiment to determine baseline tolerance and physiology by elevation, and a long-term experiment to determine the coqui's ability to acclimate to different temperatures. We collected frogs from low, medium, and high elevations. After both the short and long-term experiments, we measured critical thermal minimum (CTmin), blood glucose, oxidative stress, and corticosterone levels. CTmin was lower in high elevation frogs than low elevation frogs after the short acclimation experiment, signifying that they acclimate to local conditions. After the extended acclimation, CTmin was lower in frogs acclimated to cold temperatures compared to warm-acclimated frogs and no longer varied by elevation. Blood glucose levels were positively correlated with elevation even after the extended acclimation, suggesting glucose may also be related to lower temperatures. Oxidative stress was higher in females than males, and corticosterone was not significantly related to any predictor variables. The extended acclimation experiment showed that coquis can adjust their thermal tolerance to different temperatures over a 3-week period, suggesting the expansion of coqui into higher elevation habitats may still be possible, and they may not be as restricted by cold temperatures as previously thought.

Contrasting two urban wetland parks created for improving habitat and downstream water quality

This paper describes the ecology and management of two flow-through created wetlands that, in turn, defined 30 years of research by Bill Mitsch, 20 years in Columbus, Ohio (1992–2012) and 10 years in Naples, Florida (2012−2022). The Olentangy River Wetland Research Park was built in several stages from 1993 through 2010. The first stage was the creation of dual 1-ha kidney-shaped wetlands primarily fed by pumped Olentangy River water. A pattern of inflow that depended on river stage was maintained for 17 years. The two experimental wetlands were established by planting one of the wetlands with a variety of wetland macrophytes and leaving the second wetland unplanted to ultimately determine whether human introduction of wetland plants matter in the long run. In addition to maintaining data collection for hydrology, water quality, and other functions, these wetlands and several others constructed on the 20-ha floodplain site were heavily used as was the mesocosm compound, mostly for short-term (2 to 3 year) experiments by graduate students.Another 20-ha created wetland complex, called Freedom Park Wetlands, was constructed in 2007–2008 in Naples, Florida, at an abandoned citrus grove, to seasonally treat urban stormwater runoff. During that wet season, the design calls for an average water detention time of 18 days. The wetland system included a 1.9-ha deepwater pond for temporary storage of the urban stormwater pulses from what is mostly an urban watershed, followed by 2.7 ha of shallower vegetated wetland ponds designed to sequentially improve water quality. Within each wetland, there are three deep-water cells and two shallow-water cells. The water eventually exits the treatment wetlands via a rectangular and travels diffusely through a restored bottomland forest to the Gordon River and ultimately toward Naples Bay and the Gulf of Mexico. During our tenure at Florida Gulf Coast University's (FGCU) Everglades Wetland Research Park, Freedom Park was a venue with active mesocosm experiments in a constructed mesocosm compound. Several of these mesocosm experiments were the subjects of master's theses from FGCU and doctoral dissertations from our partner, University of South Florida. Our students also contributed to the local environmental communities by giving tours of the Freedom Park wetlands and our mesocosm research.

Sources, pathways, and abatement strategies of macroplastic pollution: an interdisciplinary approach for the southern North Sea

The issue of marine plastic pollution has been extensively studied by various scientific disciplines in recent decades due to its global threat. However, owing to its complexity, it requires an interdisciplinary approach to develop effective management strategies. The multidisciplinary scientific approach presented here focuses on understanding the sources and pathways of macroplastic litter and developing abatement strategies in the southern North Sea region. Over 2.5 years, more than 63,400 biodegradable wooden drifters were deployed with the help of citizen science to study the sources, pathways, and accumulation areas of floating marine litter. Rivers act as sinks of most of the floating marine litter released within their waterways. Short-term field experiments were also conducted to analyse the hydrodynamic and atmospheric processes that govern the transport of floating litter particles at the sea surface. Numerical models were used to examine the transport of virtual litter particles in the entire North Sea and in coastal regions. It was found that there are no permanent accumulation areas in the North Sea, and the Skagerrak and fronts can increase the residence times of floating marine litter and favour sinking. Field surveys revealed that the majority of litter objects originate from fisheries and consumer waste. To develop effective abatement strategies, the key stakeholder landscape was analysed on a regional level. The interdisciplinary approach developed in this study highlights the importance of synergizing scientific resources from multiple disciplines for a better understanding of marine plastic pollution and the development of effective management strategies.

Natural hypoxic conditions do not affect the respiration rates of the cold-water coral Desmophyllum pertusum (Lophelia pertusa) living in the Angola margin (Southeastern Atlantic Ocean)

Large, well-developed and flourishing reefs dominated by the cold-water coral Desmophyllum pertusum have recently been discovered along the Angola margin in the southeastern Atlantic Ocean living under very low oxygen concentrations (0.6–1.5 mL L−1). This study assessed the respiration rates of this coral in a short-term (10 days) aquarium experiment under naturally low oxygen concentrations (1.4 ± 0.5 mL L−1) as well as under saturated oxygen concentrations (6.1 ± 0.6 mL L−1). We found no significant difference in respiration rates between the two oxygen concentrations. Furthermore, the respiration rates of D. pertusum were in the same order of magnitude as those of the same species living under normoxic conditions in other areas. This work expands the current knowledge on the metabolic activity of cold-water corals under hypoxic conditions, evidencing that low oxygen conditions are not a general limiting factor for the overall distribution of D. pertusum.

Sustained secretion of human growth hormone from TheraCyte devices encapsulated with PiggyBac-engineered retinal pigment epithelium cells

Growth hormone (GH) deficiency is characterized by impaired growth and development, and is currently treated by repeated administration of recombinant human GH (hGH). Encapsulated cell therapy (ECT) may offer a less demanding treatment-strategy for long-term production and release of GH into circulation. We used PiggyBac-based (PB) transposon delivery for engineering retinal pigment epithelial cells (ARPE-19), and tested a series of viral and non-viral promoters as well as codon-optimization to enhance transgene expression. Engineered cells were loaded into TheraCyte macrocapsules and secretion was followed in vitro and in vivo. The cytomegalovirus (CMV) promoter supports strong and persistent transgene expression, and we achieved clonal cell lines secreting over 6 µg hGH/106 cells/day. Codon-optimization of the hGH gene did not improve secretion. ARPE-19 cells endured encapsulation in TheraCyte devices, and resulted in steady hormone release for at least 60 days in vitro. A short-term pilot experiment in immunodeficient SCID mice demonstrated low systemic levels of hGH from a single 40 µL capsule implanted subcutaneously. No significant increase in weight increase or systemic hGH was detected after 23 days in the GH-deficient lit/SCID mouse model using 4.5 µL capsules loaded with the highest secreting clone of ARPE-19 cells. Our results demonstrate that PB-mediated engineering of ARPE-19 is an efficient way to generate hormone secreting cell lines compatible with macroencapsulation, and our CMV-driven expression cassette allows for identification of clones with high level and long-term secretory activity without addition of insulator elements. Our results pave the way for further in vivo studies of encapsulated cell therapy.

Biochar Amends Saline Soil and Enhances Maize Growth: Three-Year Field Experiment Findings

Soil salinization is a significant obstacle to agricultural development in arid and semiarid regions. While short-term experiments have demonstrated the effective improvement of saline soils through biochar amendment, the long-term efficacy in sustainably ameliorating such soils remains uncertain. Addressing this knowledge gap, this study investigated the long-term effects of biochar amendment in a field setting by applying different rates of biochar to a salt-affected soil and cultivating silage maize for three consecutive years. The comprehensive assessment includes not only maize growth but also changes in soil physical and chemical properties over the study period. The results reveal a notable elevation in maize above-ground dry matter, directly correlated to the enhanced uptake of nitrogen, phosphorous, and potassium. Additionally, biochar application improves saline soil physical properties, including reduced bulk density (1–23%), increased soil large pores (0.7–12%), and macroaggregates (24–141%), and chemical properties, including a decrease in exchangeable sodium percentage (35–48%), and an increase in soil total organic carbon (112–857%), total nitrogen (9–198%), available nitrogen (12–49%), phosphorus (141–538%) and potassium (57–895%). These improvements ultimately resulted in better maize growth. However, the amelioration effect of biochar on these soil properties gradually diminished over the three-year study. Consequently, this study suggests that biochar is a promising soil amendment that can enhance maize growth in saline soil for at least three years in a field experiment, providing valuable insights for sustainable agricultural practices in salt-affected regions.

Comparison of the experimental and numerical results of coaxial-type and U-type deep-buried pipes’ heat transfer performances

The ground heat exchanger (GHE) is one of the main forms of geothermal energy utilization in middle-deep strata and typically includes coaxial-type deep-buried GHE (C-DGHE) and U-type deep-buried GHE (U-DGHE). This study compares the heat transfer characteristics of C-DGHE and U-DGHE. A field experiment was carried out on C-DGHE and U-DGHE at 2539 and 2781 m depths, respectively, in a housing estate in Xi'an. Simultaneously, the full-scale numerical models of both C-DGHE and U-DGHE at 2781 m were established based on the field logging data. A short-term experiment (72 h) and a long-term heat transfer simulation (five heating periods) serve to comprehensively compare the heat transfer performances of the two deep-buried pipe types. Results demonstrate that the heat transfer amount per unit meter of C-DGHE and U-DGHE were 132.18–145.91 W/m and 111.15–140.76 W/m respectively in this study, which means C-DGHE is superior to U-DGHE under similar boundary conditions when only heat transfer in buried pipes is considered. However, when heat transfer in buried pipes and water pump power consumption are considered simultaneously, a critical G (GC was ∼8.63 kg/s in this study) makes the comprehensive heat transfer performance of U-DGHE better than that of C-DGHE.

Abstract 5919: The significant role of HMGB1 in mesothelial cells in contributing to the mesothelioma development induced by asbestos

Abstract Diffuse Malignant mesothelioma is a very aggressive cancer that is related to asbestos exposure. We found previously that following asbestos deposition in the pleura and in the peritoneum, mesothelial cells release HMGB1 that attract granulocytes and macrophages that, in turn, secrete HMGB1. It was unknown whether the primary source of HMGB1 that drives the inflammatory process caused by asbestos, which may ensue in mesothelioma, derives from the mesothelial cells exposed to asbestos or from the granulocytes and macrophages. To study separately the contribution of mesothelial cells and of the inflammatory cells to HMGB1 secretion that drives mesothelioma development, we used two tissue-specific HMGB1 knockout mouse models: (1) An inducible mesothelial conditional HMGB1 knockout (HMGB1ΔpMeso) mouse model, and (2) a constitutive myelomonocytic-lineage knock out (HMGB1ΔMylc) mouse model. To investigate the role of HMGB1 in asbestos induced carcinogenesis in vivo, we conducted both short-term and long-term experiments in HMGB1ΔpMeso mice and in HMGB1ΔMylc mice. For the Short-term experiment, we observed that one week following the completion of the 10-weekly crocidolite i.p. injections, all the mice in experimental and control groups showed inflammation with multiple granulomas around asbestos deposits in the various tissues and organs present in the abdomen, and diffuse mesothelial hyperplasia. However, the granulomas in HMGB1ΔpMeso mice were significantly smaller compared to those found in the control WT mice. TNFα IHC stain was minimal to non-detectable in the granulomas and areas of mesothelial hyperplasia of HMGB1ΔpMeso mice, compared to a strong TNFα staining in both HMGB1ΔMylc and WT mice. For the Long-term experiment, we observed that the incidence of mesothelioma was significantly lower in HMGB1ΔpMeso mice compared with the 3 control groups including WT mice, HMGB1F/F mice and Wt1ERT2Cre/+ control mice. Moreover, HMGB1ΔpMeso mice had a significantly longer mesothelioma-specific survival compared to all three controls. Histologically, the HMGB1ΔpMeso mesotheliomas were smaller and grew largely over the surface rather than infiltrating the abdominal organs, compared to the mesotheliomas that developed in the three control groups. In summary, our findings underscore the role of HMGB1 in asbestos pathogenesis, including asbestos induced chronic inflammation and mesothelioma. Moreover, our findings elucidated the mechanisms responsible for asbestos induced inflammation and asbestos carcinogenesis, and the causal link between HMGB1, TNFα secretion and mesothelioma. Our results point to the HMGB1 secreted by mesothelial cells as the culprit and thus the ideal target to prevent the growth of mesothelioma upon asbestos exposure and during the early phases of mesothelioma growth. Citation Format: Joelle S. Suarez, Giovanni Gaudino, Tak W. Mak, Michele Carbone, Haining Yang. The significant role of HMGB1 in mesothelial cells in contributing to the mesothelioma development induced by asbestos [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5919.

Study on the adsorption characteristics of lead in soil by biochar from co-pyrolysis of rice straw and sludge

The adsorption kinetics and short-term soil adsorption experiments were carried out for the biochar (mixed charcoal) prepared by co-pyrolysis of rice straw and sludge. The results showed that the specific surface area and total pore volume of co-pyrolysed biochar were significantly increased compared with sludge pyrolysis biochar. In the lead solution adsorption experiment, the removal rate of lead ions in the solution reached 99.34% using mixed-burning biochar produced at 600 °C for 24h, and the unit mass adsorption capacity was 64.57 mg/g. In the soil adsorption experiment, 12 g/kg of mixed charcoal was added to lead-contaminated soil, and the leaching toxicity and bioavailability of lead-contaminated soil after stabilization for 30 days decreased by 45.3% and 37.0%, respectively. The soil pH value with 12 g/kg of mixed charcoal added within 30 days fluctuated between 7.03 and 7.12, and no acid or alkaline pollution was generated. Co-pyrolysed biochar can effectively reduce the leaching toxicity and bioavailability of lead in soil. For soil with a lead pollution concentration of less than 1600 mg/kg, adding 12 to 16 g/kg of co-pyrolysed biochar produced at 600 °C can achieve a satisfactory repair effect.

Engineering exosomes by three-dimensional porous scaffold culture of human umbilical cord mesenchymal stem cells promote osteochondral repair.

Improving the poor microenvironment in the joint cavity has potential for treating cartilage injury, and mesenchymal stem cell (MSC)-derived exosomes (MSC-Exos), which can modulate cellular behavior, are becoming a new cell-free therapy for cartilage repair. Here, we used acellular cartilage extracellular matrix (ACECM) to prepare 3D scaffolds and 2D substrates by low-temperature deposition modeling (LDM) and tape casting. We aimed to investigate whether MSC-Exos cultured on scaffolds of different dimensions could improve the poor joint cavity microenvironment caused by cartilage injury and to explore the related mechanisms. In vitro experiments showed that exosomes derived from MSCs cultured on three-dimensional (3D) scaffolds (3D-Exos) had increased efficiency. In short-term animal experiments, compared with exosomes derived from MSCs cultured in a two-dimensional (2D) environment (2D-Exos), 3D-Exos had a stronger ability to regulate the joint cavity microenvironment. Long-term animal studies confirmed the therapeutic efficacy of 3D-Exos over 2D-Exos. Thus, 3D-Exos were applied in the rat knee osteochondral defect model after adsorption in the micropores of the scaffold and combined with subsequent articular cavity injections, and they showed a stronger cartilage repair ability. These findings provide a new strategy for repairing articular cartilage damage. Furthermore, miRNA sequencing indicated that the function of 3D-Exos may be associated with high expression of miRNAs. Thus, our study provides valuable insights for the design of 3D-Exos to promote cartilage regeneration.

First report on biological iron uptake in the Antarctic sea-ice environment

Melting sea ice is a seasonal source of iron (Fe) to the Southern Ocean (SO), where Fe levels in surface waters are otherwise generally too low to support phytoplankton growth. However, the effectiveness of sea-ice Fe fertilization in stimulating SO primary production is unknown since no data exist on Fe uptake by microorganisms in the sea-ice environment. This study reports a unique dataset on Fe uptake rates, Fe-to-carbon (C) uptake ratio (Fe uptake normalized to C uptake) and Fe:C uptake rate (Fe uptake normalized to biomass) by in situ microbial communities inhabiting sea ice and the underlying seawater. Radioisotopes 55Fe and 14C were used in short-term uptake experiments during the 32-day Ice Station POLarstern (ISPOL) time series to evaluate the contributions of small (0.8–10 µm) and large (> 10 µm) microbes to Fe uptake. Overall, results show that over 90% of Fe was bound to the outside of the cells. Intracellular Fe (Feintra) uptake rates reached up to 68, 194, and 203 pmol Fe L−1d− 1 in under-ice seawater, bottom ice, and top ice, respectively. Inorganic carbon uptake ranged between 0.03 and 3.2 µmol C L−1 d−1, with the lowest rate observed in under-ice seawater. Importantly, between the start and end of ISPOL, we observed a 30-fold increase in Feintra normalized to carbon biomass in bottom sea ice. This trend was likely due to changes in the microbial community from a dominance of large diatoms at the start of the survey to small diatoms later in the season. As the Antarctic icescape and associated ecosystems are changing, this dataset will help inform the parameterisation of sea-ice biogeochemical and ecological models in ice-covered regions.

Экспериментальное воздействие мазута и дизельного топлива на личинок атерины

In the recent years, in the water and soils of the Black Sea are found oil products, whose concentration exceeds the allowable standard by 3 times. Due to the limited works on studying the petroleum products’ impact on the sea fish juveniles, evaluating the effect of low concentrations of fuel oil and diesel oil (½ maximum permissible concentration (MPC), MPC – 0.05 ml/l and 2 MPC) on atherina larvae was seen as important. This object has already been successfully used in testing the domestic sewage and pesticides. Despite the fact that Atherinidae species are not commercially significant, they are active pelagic fish species of the coastal zone of the southern seas and an important object in the trophic chain of the coastal biocenosis. As a results of the proper experiments, as well as of the literature data, it was proved that the above allowed concentrations of oil products should be revised from the point of view of their safety for aquatic organisms. During three days, the survival of larvae decreased by more than 50%, after which all species (including controls) died in 4-5 days. A similar experiment with diesel oil and fuel oil, due to its greater toxicity, included a feeding factor. Atherina larvae consumed both cysts and branchiopod nauplii, however, on the third day their intestines were empty. This fact, as well as survival rates exceeding the control values, is probably part of the organism compensatory reaction in response to the toxicant presence. From a methodological point of view, it would be more correct to carry out even acute and short-term toxicological experiments with feeding, because they significantly influence the determination of toxicity of the environment or of a specific xenobiotic.

Development of a novel periodic venting-controlled membrane biofilm reactor for hydrogenotrophic denitrification: Process performance and microbial mechanism

The performance of anaerobic membrane biofilm reactor (MBfR) has long been underexploited due to the limited delivery of active gas to the biofilm on the close-end hollow fiber membranes (HFMs). Here, to establish a valid scheme for overcoming this obstacle, we coupled a denitrifying H2-based MBfR to an automatic venting unit for intermittently updating intramembrane gas, and a microsensor unit for investigating the H2 diffusion behavior. In short-term experiments, at the HFM length of 60 cm and H2 supplying pressure of 1.2 atm, the periodic venting strategy, in which the venting time and interval were set as 30 s and 17 min, respectively, was validated to be capable of improving the denitrification performance of H2-based MBfR. The results of long-term experiment show that compared to the conventional close-end operation, the around 50% increase in denitrification flux was achieved in the periodic venting-controlled system, which was found to be associated with the increased biofilm thickness and the evolution of denitrifying bacteria (DNB) and functional genes in the biofilm at the HFM distal end. Model outputs manifest that regardless of the HFM length, the biofilm regions with high DNB activity at the distal end were much narrower than those at the proximal end of the close-end HFMs; owing to the improved H2 delivery, the active biofilm region at the distal end of 60 cm HFM was significantly enlarged from 0–225 µm in the case of close-end operation to 0–450 µm in the venting-controlled system. The proposed periodic venting strategy opens a new avenue for the management of anaerobic MBfR.

Supplementation with Akkermansia muciniphila improved glucose metabolism disorder in common carp (Cyprinus carpio L.)

Akkermansia muciniphila (Akk), a promising next-generation probiotics, has been identified as an effective means for alleviating hepatic steatosis and insulin resistance in mammals. However, its probiotic effect and mechanism remain unclear so far in aquaculture. This study aimed to investigate how Akk is involved in the glucose metabolism of common carp and its mechanism. A total of 300 healthy carp with the same size (26.5 ± 3.0 g) were randomly divided into four groups: G25/A0 group (25% glucose +0 CFU/g Akk), G25/A108 group (25% glucose +1 × 108 CFU/g Akk), G50/A0 group (50% glucose +0 CFU/g Akk), and G50/A108 group (50% glucose +1 × 108 CFU/g Akk). These groups were placed into three replicate tanks (25 fish/tank). At the end of a 60-day feeding trial, the effects of Akk supplementation on the growth performance, glucose metabolism, and intestinal microflora composition of common carp were investigated. Then, a short-term gavage experiment was conducted to further explore the regulatory effects of live Akk, pasteurized Akk, and cell-free supernatant on the glucose metabolism of carp. The results showed that Akk reduced the blood glucose and TG content of carp fed with high glucose, promoted glycolysis, inhibited liver gluconeogenesis, and reduced the diversity and richness of intestinal microbiota. The pasteurized Akk displayed a stronger role in reducing serum TG and promoting glycolysis than the live Akk and cell-free supernatant. In summary, Akk may be considered as one of the ideal new probiotics used in aquaculture.

Intermittent and temporally variable bioturbation by some terrestrial invertebrates: implications for ichnology

Bedding planes and vertical sections of many sedimentary rock formations reveal bioturbation structures, including burrows, produced by diverse animal taxa at different rates and durations. These variables are not directly measurable in the fossil record, but neoichnological observations and experiments provide informative analogues. Comparable to marine invertebrates from many phyla, a captive beetle larva burrowing over 2 weeks showed high rates of sediment disturbance within the first 100 h but slower rates afterwards. Tunnelling by earthworms and adult dung beetles is also inconstant—displacement of lithic material alternates with organic matter displacement, often driven by food availability with more locomotion when hungry. High rates of bioturbation, as with locomotion generally, result from internal and external drives, slowing down or stopping when needs are filled. Like other processes affecting sediment deposition and erosion, rates can drastically differ based on measured timescale, with short bursts of activity followed by hiatuses, concentrated in various seasons and ontogenetic stages for particular species. Assumptions of constant velocities within movement paths, left as traces afterward, may not apply in many cases. Arguments about energetic efficiency or optimal foraging based on ichnofossils have often overlooked these and related issues. Single bioturbation rates from short-term experiments in captivity may not be comparable to rates measured at an ecosystem level over a year or generalized across multiple time scales where conditions differ even for the same species. Neoichnological work, with an understanding of lifetime variabilities in bioturbation and their drivers, helps connect ichnology with behavioural biology and movement ecology.

A NOVEL RP-HPLC GRADIENT ELUTION TECHNIQUE FOR BIOANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR ESTIMATING GALLIC ACID IN WISTAR RAT PLASMA

Objective: Present study aimed to develop and validate a novel, unique, simple, quick, cost-effective, sensitive, specific, accurate, precise, rugged, and robust bioanalytical method for the quantification of gallic acid in rat plasma by reverse phase high-performance liquid chromatography (RP-HPLC) using gradient elution technique. Methods: The stationary phase was a Zorbax SB C18 5 µ (4.6*150) mm column, with the mobile phase being water with 0.1 percent formic acid (A): acetonitrile (ACN) with 0.08 percent formic acid (B). Gradient chromatographic method was used throughout this experiment from the point of view of the estimation of gallic acid from herbal formulations when present along with other phytoconstituents. So at the gradient method, all the present phytoconstituents has cleared off from the column and no any strongly adsorption of phytoconstituents occurred. The experiment was carried out at a flow rate of 1.0 ml/min at 30 °C utilising PDA detectors at 271 nm. The proposed method was validated for different parameters. Results: The approach was found to be linear in the concentration range of 0.5-100 µg/ml, with a r2 of 0.9998. There was not observed any interference of co-eluting peaks of endogenous compounds from the biological matrix at the same retention time (Rt) of gallic acid. The RSD (%) of intra and interday precision was found to be within acceptable limit. The overall % mean recovery was found to be 99.97%. LOD and LOQ were found to be 0.1 and 0.5 μg/ml, respectively. In terms of fluctuation in essential parameters and operating settings, the devised bioanalytical approach was shown to be rugged and resilient. Short-term, long-term, autosampler, bench-top, and freeze-thaw stability experiments revealed that gallic acid is stable. Conclusion: The developed method described in this report was found to be well within an acceptable range. Hence, in the future, this method can be used successfully for the estimation of gallic acid alone or in combination with another analyte or marker present in bulk or an extract containing various phytoconstituents in pharmacokinetic, bioequivalence, and therapeutic drug monitoring studies in clinical laboratories.

Morphological changes in the testes of white rats and humans in acute and chronic alcoholic intoxications: Experimental and sectional study

BACKGROUND: This study analyzed the effects of ethyl alcohol and narcotic drugs on male reproductive organs. Practically no studies have examined morphological transformations in the testicles during alcohol intoxication, which, at the current level of ethanol consumption by men of reproductive age, is a social and medical problem that is far from being solved.
 AIM: Through short-term and long-term experiments, this study aimed to examine the severity and dynamics of morphological changes in the gonads during alcohol intoxication in mature rats and in comparison with those in individuals who died from alcoholic disease and severe alcohol catamnesis.
 MATERIAL AND METHODS: The study examined the testicles of sexually mature rats that were subjected to acute and chronic alcohol intoxications (from 2 weeks to 6 months) and testicles of persons who died in which ethyl alcohol was found in the blood (at least 5 promile) and alcohol catamnesis were noted.
 RESULTS: In both experimental and sectional materials, the stroma of the testicles was characterized by severe circulatory disorders with plethora and stasis in post-capillaries and small veins, edema, and perivascular and interstitial sclerosis. The inhibition of spermatogenesis in the sectional material was more pronounced, which indicated that alcohol was the main etiopathological factor in these changes.
 CONCLUSION: Chronic alcohol intoxication in both rats and men has damaging effects both directly, with changes in the stroma and testicular parenchyma, and indirectly on the overlying links of the reproductive system (hypothalamus and pituitary gland). The neurotoxic, microangiopathic, and disenergetic effects of ethanol inhibit normal spermatogenesis. Ultimately, the negative effect based on the morphological analysis was observed in the hypotesticular conditions and morphological manifestations of the testicular wasting syndrome.

Growth and Plasma Triiodothyronine Concentrations Are Modified by Selenium Deficiency and Repletion in Second-Generation Selenium-Deficient Rats

Classical glutathione peroxidase (GPX) is a useful Se-dependent parameter for determining Se status, but loss of GPX activity alone cannot explain the full effects of Se deficiency. The recent identification of type I thyroxine 5′-deiodinase as a Se-dependent enzyme provides a new potentially critical role for Se. To develop a model of impaired growth due to Se deficiency, second generation deficient weanling rats were fed a Se-deficient amino acid diet with adequate vitamin E and methionine. Initial growth rates of deficient males and females were 53 and 63%, respectively, of rats fed 0.1 µg Se/g diet. In short-term experiments with deficient males, liver Se and GPX activity were reduced 99%, liver glutathione-s-transferase activity was increased 114%, plasma thyroxine concentrations were increased 67%, plasma triiodothyronine was decreased 23% and the plasma triiodothyronine:thyroxine ratio was decreased 55%, compared with rats fed 0.2 µg Se/g diet. When deficient rats were injected on d 14 with 0, 1, 5 or 10 µg Se/100 g, rats grew 4.45, 7.62, 7.17 and 9.05 g/d, respectively, over the next 7 d. Injection with 10 µg Se/100 g restored plasma thyroxine and triiodothyronine concentrations 7 d later. Rats injected with 1 µg Se/100 g rat had significantly altered plasma thyroxine and triiodothyronine concentrations 1 but not 7 d after injection. Infusion of Se-deficient rats with 438 ng triiodothyronine/d for 7 d restored plasma triiodothyronine concentrations but did not increase growth rate compared with rats infused with saline. This model produced a significant growth depression that was significantly reversed by as little as 1 µg Se/100 g rat, but not by triiodothyronine infusion, suggesting that other Se-dependent roles in addition to 5′-deiodinase and GPX are necessary for adequate growth.

Soil microbial respiration adapts to higher and longer warming experiments at the global scale

Warming can affect soil microbial respiration by changing microbial biomass and community composition. The responses of soil microbial respiration to warming under experimental conditions are also related to background conditions and the experimental setup, such as warming magnitude, duration, and methods. However, the global pattern of soil microbial respiration in response to warming and underlying mechanisms remain unclear. Here, we conducted a global meta-analysis of the response of soil microbial respiration to warming by synthesizing data from 187 field experiments. We found that experimental warming significantly increased soil microbial respiration and microbial biomass carbon by 11.8% and 6.4%, respectively. The warming-induced increase in microbial carbon decomposition was positively correlated with increased microbial biomass carbon, but not community composition. Moreover, the positive response of soil microbial respiration marginally increased with warming magnitude, particularly in short-term experiments, but soil microbial respiration adapted to higher warming at longer timescales. Warming method did not significantly affect the response of microbial respiration, except for a significant effect with open top chamber warming. In addition, the impact of warming on soil microbial respiration was more pronounced in wetter sites and in sites with lower soil pH and higher soil organic carbon. Our findings suggest that warming stimulates microbial respiration mainly by increasing microbial biomass carbon. We also highlight the importance of the combination of warming magnitude and duration in regulating soil microbial respiration responses, and the dependence of warming effects upon background precipitation and soil conditions. These findings can advance our understanding of soil carbon losses and carbon-climate feedbacks in a warm world.