Mercury Chloride Research Articles

New advances in the enhancement of direct mercury speciation in solid matter on the example of HgCl, CH3HgCl, HgS and HgSO4 using programmable thermal release in combination with elecrothermal atomic absorption spectrometry

Mercury is considering as hazardous pollutant presented as a number of various species characterized by different migration routes, bioavailability and toxicity. In this regard, the characterization of natural and a fortiori anthropogenic environment by the concentration of various chemical forms of mercury is relevant to assess the degree of its impact on living organisms. From this point of view, solid samples are the most problematic ones due to the need for preliminary extraction of analytes into solution. The promising approach for this purpose is analysis based on a combination of thermal release as separation way with sequential electrothermal atomic absorption spectrometric detection (TR-ETA-AAS). The present work is based on research of the thermal behavior of individual mercury species in argon atmosphere when the evaporation and atomization zones are separated and a programmable heating algorithm is implemented. To unify an analytical procedure the dilution of reference and analyzed samples with aluminum oxide was applied. The developed method allows determination of the species most often found in natural and contaminated environments: mercury (II) chloride, methylmercury chloride, mercury sulfide and sulphate at the level of 0.003–0.030 µg with a reproducibility of 10–25 %,. The trueness of the proposed approach has been confirmed using certified reference material ERM CE464 and spiking method.

Synthesis and Reactivity of Bis[2,6‐bis(diphenylphosphino)phenyl]antimony ChlorideTowards Mercury Chlorides. Unexpected Transmetallation and Sb–Sb Bond Formation.

The reaction of the lithium reagent 2,6‐(Ph2P)2C6H3Li with SbCl3 provided the diarylantimony chloride [2,6‐(Ph2P)2C6H3]2SbCl (1) as sole product. The reaction of 1 with an equimolar mixture of HgCl2 and Hg2Cl2 proceeded with partial transmetallation and provided [2,6‐(Ph2P)2C6H3SbCl]2 (2) and [2,6‐(Ph2P)2C6H3]2Hg×2 HgCl2 (3). The molecular structure of 2 reveals a dinuclear arrangement and the unexpected formation of a central Sb‐Sb single bond (2.7862(4) Å). The molecular structure of 3 exhibits a trinuclear mercury string arrangement comprised of two symmetry equivalent mercurophilic Hg×××Hg interactions (3.2632(3) Å).

New Research on the Origin of Mosaic Gold

This article examines the origins of the golden pigment known as mosaic gold (SnS2), formed through the sublimation of tin with mercury, sulphur, and ammonium chloride. It explores the textual transmission of mosaic gold from the earliest known written testimonies, as well as the earliest material remnants of the pigment during the thirteenth and fourteenth centuries. Additionally, the study introduces and analyses two new recipes from an earlier date: one comes from the Greek treatise known as the Anonymous of Zuretti; and the other from the Latin alchemical work attributed to pseudo-Avicenna, De anima. The analysis of these new recipes allows for a better understanding of the origin of the pigment and its connection with the medieval alchemical tradition inherited from the Arabic world. Based on these testimonies, the study proposes a new hypothesis about the origin, development, and etymology of mosaic gold.

Involvement of aquaporins in Shiga toxin-induced swelling and water transport dysfunction in human renal microvascular endothelial cells

One of the hallmarks of Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is kidney damage. Our previous research demonstrated that Shiga toxin type 2 (Stx2a) decreases cell viability and induces swelling of human glomerular endothelial cells (HGEC). However, Stx2a can disrupt net water transport across HGEC monolayers without affecting cell viability. This work aimed to elucidate the possible mechanisms involved in the water transport disruption caused by Stx2a across HGEC monolayers. We investigated paracellular and transcellular water transfer across HGEC by analyzing the passage of FITC-Dextran and the hydrostatic pressure (Phydr) and measuring the osmotic pressure (Posm), respectively. Stx2a selectively affected the transcellular pathway without impacting the paracellular route. Furthermore, Stx2a cell swelling was prevented by pretreatment with aquaporin inhibitors tetraethylammonium chloride (TEA), Mercury (II) chloride (HgCl2) or TGN-020, suggesting aquaporin involvement in this process. Confocal microscopy revealed that Stx2a increased HGEC total volume, which TEA and TGN-020 counteracted. Additionally, we identified in HGEC not only the expression of aquaporin-1 (AQP1) but also the expression of aquaporin-4 (AQP4). Surprisingly, we observed a decrease in the expression of both AQPs after Stx2a exposure. Our findings suggest that Stx2a may induce water movement into HGEC via AQP1 and AQP4, increasing total cell volume. Subsequently, decreased AQP1 and AQP4 expression could inhibit transcellular water transfer, potentially as a protective mechanism against excessive water entry and cell lysis.

Effects of Gingko Biloba Extract and L-Ascorbic Acid on Some Hematological, Biochemical, and Hepatic-Architectural Alterations in Mercury Chloride Intoxicated Adult Wistar Rat.

The study investigated the effects of Ginkgo biloba and Ascorbic acid (A.A) on mercury chloride (HgCl2) toxicity in Wistar rats. Forty-two adult Wistar rats were randomly divided into seven groups (n=6). Group I served as control. Groups II–VII received 5 mg/kg of HgCl2. Groups III and IV received 100 mg/kg and 500 mg/kg of A.A respectively, while groups V and VI daily received 100 mg/kg and 500 mg/kg of EGB761 respectively. Group VII received 100 mg/kg of A.A and EGB761. All administration were done orally, once daily for 21 days. Mercury exposure caused significant (p<0.05) decreases in RBC (3.62.00±0.75), hemoglobin (8.67±0.14), and PCV (32.93±0.47) in group II when compared to the control group, while significantly (p<0.05) increasing white blood cell count (18.57±1.51). Liver function tests significantly (p<0.05) increased Alanine transaminase (1.38±1.51), Aspartate Transaminase (10.11±4.21), and Alkaline Phosphatase (1.89±0.51) in group II when compared to Control. Biochemical analysis revealed a significant (p<0.05) increase in malondialdehyde levels and a significant (P<0.05) decrease in superoxide dismutase (3.86 ± 0.69), glutathione (10.08 ± 2.13), and catalase (3.65 ± 0.2) levels in group II. However, treatment with ascorbic acid and EGB761 significantly (P<0.05) increased in Groups IV (6.15 ± 0.38); VI (6.28 ± 0.40), and VII (6.19 ± 0.41), SOD levels in Groups IV (6.15 ± 0.38); VI (6.28 ± 0.40) and VII (6.19 ± 0.41) and GSH level when compared to the HgCl2 group. Histological examination showed moderate hepatocyte necrosis in group II, while treatment with EGB761 and A.A showed moderate healing, binucleate nuclei, and a slight decrease of distorted sinusoids and normalization of liver structure. The study concludes that EGB761 and A.A have hepatoprotective effects on mercury-induced hepatotoxicity in a dose-dependent manner. The findings suggest that these antioxidants may be useful in mitigating the harmful effects of mercury exposure on the liver.

The Neuroprotective Effect of Calotropis procera Against Toxicity of Mercury Chloride

Background: Central nervous system intoxication can result from exposure to various toxins, including mercury chloride. Although several chelating agents are available for mercury chloride detoxification, their efficacy can diminish over time. Calotropis procera, a medicinal plant, has shown potential as a protective agent against mercury chloride-induced brain damage. This study aims to evaluate the protective effects of Calotropis procera in mitigating mercury chloride toxicity. Experimental animal design: This study investigates the protective effects of Calotropis procera against mercury chloride toxicity in Wistar albino rats. A total of 36 rats, comprising both males and females, were housed under controlled laboratory conditions and divided into two main groups based on five animals. Each group was further subdivided into five subgroups: a control group, a group treated with Calotropis procera, a group treated with mercury chloride, a group treated with both mercury chloride and Calotropis procera and a group receiving Calotropis procera alongside mercury chloride. Treatments were administered for 20 days. After the treatment period, the rats were euthanised, and brain tissues were collected for histopathological analysis. After the brain tissues were fixed in 10% saline-buffered formalin, they were processed through a series of ascending grades of ethanol to dehydrate them. The tissues were then cleared in xylene and embedded in paraffin. The paraffin-embedded brains were treated three times with pure paraffin to ensure proper infiltration and were subsequently moulded into blocks. Sections of 5 µm thickness were prepared using a Leica microtome and stained with Haematoxylin and Eosin (H&E) for histopathological examination. The study adhered to ethical guidelines and was approved by the relevant regulatory body. The results of this study demonstrated that mercury chloride caused significant cerebral toxicity, manifesting as inflammation and pyknosis of the nuclei. Calotropis procera reduced mercury toxicity and preserved the nuclei in male rats. In female rats, Calotropis procera completely preserved the brain tissue.

Synthesis of Halogen-Substituted [12]Mercuracarborands-4. Crystal Structure of {[(9,12-I<sub>2</sub>-C<sub>2</sub>B<sub>10</sub>H<sub>8</sub>-1,2-Hg)<sub>4</sub>]Cl}Na(H<sub>2</sub>O)<sub>n</sub>

The reactions of the dilithium derivatives of 9,12-dihalogen-ortho-carboranes 1,2-Li2-C2B10H8-9,12-X2 (X = Cl, Br, I) with mercury chloride HgCl2 afford a number of complexes of the chloride ion with the halogen derivatives of [12] mercuracarborand-4: {[(9,12-X2-C2B10H8-1,2ʹ-Hg)4]Cl}Na · nH2O. The molecular crystal structure of the complex of the[12]mercuracarborand-4 octaiodine derivative with the chloride ion is determined by X-ray diffraction. The substituents at the periphery of the mercury-containing macrocycle are found to exert a substantial effect on the macrocycle geometry leading to the transition from the planar to butterfly conformation, whose geometry is predetermined by a set of intermolecular interactions in the crystal.

In-silico analysis of ethanol peel extract of Citrus sinensis on mercury chloride-induced prefrontal cortex damage in Wistar rat

This study evaluated the effect of ethanolic extract of Citrus sinensis peel on mercury chloride-induced changes in the prefrontal cortex of adult Wistar rats. Twenty-five Wistar rats were purchased and divided into five groups containing five animals in each group. Group 1 was administered with distilled water, Group 2, Group 3, Group 4, and Group 5 were administered with 5 mg/kg of mercury chloride only, 5 mg/kg of mercury chloride and 140 mg/kg Silymarin, 5 mg/kg mercury chloride and 1000 mg/kg of ethanoic extract of orange peel, and 5 mg/kg mercury chloride and 1500 mg/kg of ethanoic extract of orange peel. All administration was done orally and the administration lasted for 14 days. The animals were sacrificed humanely using 75 mg/kg ketamine intraperitoneally and prefrontal was dissected out. Part was homogenized in 0.1M phosphate buffered saline for the estimation of superoxide dismutase (SOD), and catalase (CAT) activities, and Malondialdehyde (MDA) level and the other part was fixed by immersion in 10 neutral buffered formal-saline for histological evaluation. The chemical structure of sixteen compounds from Citrus sinensis peel obtained from GC-MS analysis reported in the literature were retrieved from the PubChem compound database and the crystal structure of human peroxisome proliferator- activated receptor gamma (PPARγ; PDB:ID: 2P4Y) reported to increase the expression of catalase gene, human extracellular copper-zinc superoxide dismutase enzyme (PDB ID: 2JLP) and mammalian 15-lipoxygenase - 1 enzyme (PDB ID: 2P0M) responsible for the production of lipid peroxidation were retrieved from the PDB database. Ligands and protein preparation, docking and MM-GBSA relative binding free energy calculation were done in Maestro 2023.1. Data obtained was analyzed using the IBM SPSS (version 25) using one-way ANOVA and p-value < 0.05 was considered statistically significant. The results indicate that the MDA level in control Group(13.29±1.183 μmol) is statistically significantly lower compared to the Group 2 (21.88±1.96 μmol), group 3 (27.44±3.52 μmol), Group 4 (22.20±1.16 μmol) and Group 5 (25.40±3.13 μmol). No statistically significant difference was observed in SOD activity. The CAT activities in control group (53.51±6.83 nmol/ml) was statistically significantly lower compared to the group 2 (26.21±3.70 nmol/ml), Group 3 (27.17±5.32 nmol/ml), Group 4 (25.30±4.24 nmol/ml) and Group5 (26.59±4.22 nmol/ml).The present study suggests, ethanolic extract of Citrus sinensis peel have protective effects on mercury-induced changes in prelimbic part of the prefrontal cortex of adult Wistar rats.

Biochemical and histological analysis of ethanol peel extract of Citrus sinensis on mercury chloride-induced prefrontal cortex damage in Wistar rats

Mercury is one of the heavy metals which is found extensively in many environmental and certain occupational settings. It is the third most dangerous heavy metal and its toxicity causes serious risks to health through unfavorable pathological and biochemical effects. Sweet orange is the fruit of the citrus species (Citrus sinensis) in the family Rutaceae.. Over time there has been increasing interest in the utilization of these peels for both nutritional and medicinal purposes. Studies have reported the antioxidant potential of orange peel oil in laboratory rodents, indicating its protective effect against oxidative stress-mediated ailments. The study evaluated the effect of ethanolic extract of Citrus sinensis peel on mercury chloride-induced changes in the prefrontal cortex of adult Wistar rats. Twenty-five Wistar rats were purchased and divided into five groups containing five animals in each group. Group 1 was administered with distilled water, Group 2, Group 3, Group 4, and Group 5 were administered with 5 mg/kg of mercury chloride only, 5 mg/kg of mercury chloride and 140 mg/kg Silymarin, 5 mg/kg mercury chloride and 1000 mg/kg of ethanoic extract of orange peel, and 5 mg/kg mercury chloride and 1500 mg/kg of ethanoic extract of orange peel. All administration was done orally and the administration lasted for 14 days. The animals were sacrificed humanely using 75 mg/kg ketamine intraperitoneally and prefrontal was dissected out. Part was homogenized in 0.1M phosphate buffered saline for the estimation of superoxide dismutase (SOD), and catalase (CAT) activities, and Malondialdehyde (MDA) level and the other part was fixed by immersion in 10 neutral buffered formal-saline for histological evaluation. The results indicate that the MDA level in control Group(13.29±1.183 μmol) is statistically significantly lower compared to the Group 2 (21.88±1.96 μmol), group 3 (27.44±3.52 μmol), Group 4 (22.20±1.16 μmol) and Group 5 (25.40±3.13 μmol). No statistically significant different that was observed in SOD activity. It CAT activities in control group (53.51±6.83 nmol/ml) is statistically significantly lower compared to the group 2 (26.21±3.70 nmol/ml), Group 3 (27.17±5.32 nmol/ml), Group 4 (25.30±4.24 nmol/ml) and Group5 (26.59±4.22 nmol/ml). Protective role of the extract was observed from the histological evaluation. This study suggests that ethanolic extract of Citrus sinensis peel have protective effects on mercury-induced changes in prelimbic part of the prefrontal cortex of adult Wistar rats.

Rapid Response of Daphnia magna Motor Behavior to Mercury Chloride Toxicity Based on Target Tracking.

A rapid and timely response to the impacts of mercury chloride, which is indispensable to the chemical industry, on aquatic organisms is of great significance. Here, we investigated whether the YOLOX (improvements to the YOLO series, forming a new high-performance detector) observation system can be used for the rapid detection of the response of Daphnia magna targets to mercury chloride stress. Thus, we used this system for the real-time tracking and observation of the multidimensional motional behavior of D. magna. The results obtained showed that the average velocity (v¯), average acceleration (a¯), and cumulative travel (L) values of D. magna exposed to mercury chloride stress changed significantly under different exposure times and concentrations. Further, we observed that v¯, a¯ and L values of D. magna could be used as indexes of toxicity response. Analysis also showed evident D. magna inhibition at exposure concentrations of 0.08 and 0.02 mg/L after exposure for 10 and 25 min, respectively. However, under 0.06 and 0.04 mg/L toxic stress, v¯ and L showed faster toxic response than a¯, and overall, v¯ was identified as the most sensitive index for the rapid detection of D. magna response to toxicity stress. Therefore, we provide a strategy for tracking the motile behavior of D. magna in response to toxic stress and lay the foundations for the comprehensive screening of toxicity in water based on motile behavior.

Mopa Mopa and Barniz de Pasto at the Victoria and Albert Museum: Recent Developments

This paper summarises the research carried out so far on barniz de Pasto objects from the Victoria and Albert Museum (V&A) and outlines future areas of development for our collection of Indigenous lacquer from Latin America. The V&A was the first UK public institution to identify objects decorated with barniz de Pasto within its collection. Two of these were acquired in 2015 and 2018; others had entered the collection between 1855 and 1902 but were recognised as barniz de Pasto only after 2018. The acquisition in 2015 of a cabinet marked the start of a research campaign to understand the materiality and context of all the museum’s barniz de Pasto objects. The analytical techniques used included X-radiography, polarised light microscopy and digital microscopy, Raman microscopy, X-ray fluorescence (point and scanning), chromatography (py-GC–MS and LC–DAD–MS), Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray micro-computed tomography. Unexpected discoveries were made along the way, including the characterisation and documentation of mercury white (mercury(I) chloride, or calomel) used as a white pigment, a world first. Gel-based cleaning methods were used to remove a non-original, discoloured, natural varnish covering nearly the entire surface of one of the objects, and the recent overpaint on its lid, revealing original surfaces which had been repaired and drastically repainted in the second half of the twentieth century.

Protective Effects of Syringic Acid Against Oxidative Damage, Apoptosis, Autophagy, Inflammation, Testicular Histopathologic Disorders, and Impaired Sperm Quality in the Testicular Tissue of Rats Induced by Mercuric Chloride.

Mercury (Hg) is one of the most toxic heavy metals that damage testicular tissue. Mercury chloride (HgCl2) is one of the most toxic forms of mercury that can easily cross biological membranes. Syringic acid (SA) is a natural flavonoid found in many vegetables and fruits. In this study, the effects of SA against HgCl2-induced testicular damage in rats were determined by biochemical, histopathological, and spermatological analyses. For this study, a total of 35 Spraque Dawley rats were used. Rats were divided into five groups as control, HgCl2, SA 50, HgCl2 + SA 25, and HgCl2 + SA 50. HgCl2 was administered intraperitoneal (IP) at a dose of 1.23 mg/kg/bw, while SA was administered by oral gavage at doses of 25 and 50 mg/kg/bw. The rats were then sacrificed, and testicular tissues were removed. HgCl2 caused an increase in MDA level and a decrease in SOD, CAT, and GPx activity and GSH level in the testicular tissue of rats. HgCl2 is involved in the increase of eIF2-α, PERK, ATF-4, ATF-6, CHOP, NF-κB, TNF-α, IL-1β, Apaf-1, Bax, and Caspase-3 mRNA expression. HgCl2 caused a decrease in sperm motility, an increase in the rate of abnormal sperm and sperm DNA fragmentation in rats. However, SA oral administration dose-dependently inhibited endoplasmic reticulum stress, oxidative stress, inflammation, and apoptosis and preserved epididymal sperm quality and testicular histoarchitectures. In conclusion, SA had protective effects against HgCl2-induced testicular oxidative damage, inflammation, endoplasmic reticulum stress, and apoptosis.

In vitro shoot regeneration system from leaves wrapped by bud scales of a multipurpose tree (Neolamarckia cadamba)

Neolamarckia cadamba (N. cadamba) is an evergreen tree species known for its rapid growth, remarkable wood properties, and significant value in medicine, feeding, and landscape. In order to clone a N. cadamba individual with excellent genotype, a plant regeneration protocol was successfully established with leaves wrapped by bud scales as explants. The optimal sterilization method for the leaves was 0.1% Mercury Chloride (HgCl2) treatment for 1 min before culturing on Murashige and Skoog’s medium (MS) supplemented with 3.0 mg/L Thidiazuron (TDZ), 0.1 mg/L 2–4 Dichlorophenoxyacetic acid (2-4D), 0.05 mg/L α-Naphthaleneacetic acid (NAA) and 1 mL/L Plant Preservative Mixture (PPM) to induce calluses. The medium containing 1 mL/L PPM could effectively inhibit explant contamination without an unfavorable impact on the final induction rate of callus from the leaves. Three types of calluses were induced from the leaves cultured on the above medium. Among them, only the Type II callus, which was green and nodular, had few particle masses, could differentiate into adventitious shoots on the MS medium supplemented with 1.5 mg/L 6–Benzylaminopurine (6-BA) and 0.05 mg/L NAA, with the induction rate of 78.89% and adventitious shoot number per callus of 11.67. The adventitious shoots were proliferated on the MS medium supplemented with 1.0 mg/L 6-BA and 0.05 mg/L Indole-3- butyric acid (IBA) with the proliferation coefficient of 3.37. And the micro-shoots developed roots in the MS medium supplemented with 0.05 mg/L NAA and 0.05 mg/L IBA. The regeneration protocol can be used in the propagation and large scale production of seedlings with the same genotype as an excellent individual of N. cadamba in the field.

Quercetin alleviates kidney damage caused by mercury Chloride: The protective effects of quercetin on autophagy and inflammation were studied based on TRIM32/TLR4/LC3 pathway

ObjectiveMercury is one of the heavy metal pollutants causing serious harm to human health. Quercetin was observed to repair kidney damage through the TLR4/TRIM32 pathway, and the detoxification effect of quercetin on heavy metal poisoning was observed. MethodsFor the study, the researchers divided 40 male mice from the KM strain into five groups: control, HgCl2, QU30, HgCl2+QU15, and HgCl2+QU30. The biological effects of those mice in each group were detected by the biochemical experiment, histopathology experiment and protein expression experiment respectively. ResultsHgCl2 had effects in increasing the level of malondialdehyde (MDA) and decreasing the activity of antioxidant enzymes (P < 0.05). HgCl2 induced inflammation by increasing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and Toll Like Receptor 4 (TLR-4) (P < 0.05). The expression of creatinine (CRE) and urea nitrogen (BUN) showed that HgCl2 promoted kidney injury. HgCl2 altered renal tissue integrity and TRIM32 expression which resulted in the increased autophagy associated protein levels of LC3. In contrast, quercetin reduced oxidative stress, autophagy, inflammation and histopathological changes (P < 0.05). ConclusionQuercetin has the renal protection effects of anti-inflammation, anti-oxidation and anti-autophagy.

Promising the potential of β-caryophyllene on mercury chloride-induced alteration in cerebellum and spinal cord of young Wistar albino rats.

Mercury chloride (ME) is a chemical pollutant commonly found in the environment, which can contribute to undesirable health consequence worldwide. The current study investigated the detrimental impact of ME on the cerebellum and spinal cord tissues in 6-8-week-old female rats. We also evaluated the neuroprotective efficacy of β-caryophyllene (BC) against spinal and cerebellar changes caused by ME. Thirty-five young Wistar albino rats were randomly chosen and assigned into five groups: control (CO), olive oil (OI), ME, BC, ME + BC. All samples were analysed by means of unbiased stereological, biochemical, immunohistochemical, and histopathological methods. Our biochemical findings showed that SOD level was significantly increased in the ME group compared to the CO group (p < 0.05). We additionally detected a statistically significant decrease in the number of cerebellar Purkinje cells and granular cells, as well as spinal motor neuron in the ME group compared to the CO group (p < 0.05). In the ME + BC group, the number of Purkinje cells, granular cells, and spinal motor neurons was significantly higher compared to the ME group (p < 0.05). Decreased SOD activity in the ME + BC group was also detected than the ME group (p < 0.05). Immunohistochemical (the tumour necrosis factor-alpha (TNF-α)) and histopathological examinations also exhibited crucial information in each of the group. Taken together, ME exposure was associated with neurotoxicity in the cerebellum and spinal cord tissues. BC treatment also mitigated ME-induced neurological alteration, which may imply its potential therapeutic benefits.

A simple, safe method for preserving dissolved methane in freshwater samples using benzalkonium chloride

AbstractMethane (CH4) dissolved in water is readily consumed by CH4‐oxidizing bacteria, so the possibility of the dissolved CH4 concentration (dCH4) in sampled water changing before analysis is a concern. To determine the accurate in situ dCH4 level, mercury chloride (HgCl2) or sodium azide (NaN3) is traditionally used for sample preservation. However, these preservatives are very toxic and great care must be taken when adding them to samples. Benzalkonium chloride (BAC), a quaternary ammonium salt cationic surfactant, is a readily available disinfectant that is less harmful to the human body than HgCl2, NaN3, and other preservatives. In this study, we investigated the usefulness of BAC in preserving dCH4 in swamp water, which is a critical terrestrial source of CH4. The dCH4 in samples without BAC decreased immediately after sample collection, whereas the dCH4 in the samples with added BAC did not change significantly for at least 15 d. In addition, when BAC was added to 18 water samples with different water chemistries, the dCH4 did not change significantly from immediately after sampling to 1 week after sampling (average difference: 3%). Thus, in the water samples used in this study, BAC effectively preserved dCH4 in the samples for at least 1 week. Further testing of the effect of BAC on the preservation of dCH4 in different types of water samples worldwide will help to establish a more complete, simple, and safe method.

Establishment of a callus induction system of Saxifraga stolonifera Meerb. and its response to different elicitors

Elicitation is a well-known strategy for increasing the accumulation of secondary metabolites in callus cultures. In this study, a callus induction system for Saxifraga stolonifera Meerb. was developed, and elicitors were used to enhance secondary metabolite production. Tender leaves of S. stolonifera were used as explants for in vitro culture. We examined callus induction characteristics of S. stolonifera and its response to various elicitors by assessing the sterilization conditions of the explants, varying hormone ratios, and determining the optimal concentrations of salicylic acid (SA), Sodium nitroprusside (SNP) and methyl jasmonate (MeJA). The results revealed that sterilizing the explants with 70% ethanol for 40 s, followed by 0.1% mercury chloride for 10 min, resulted in a survival rate of 82.22% during tissue culture. Following these sterilization methods, callus formation was successfully induced on Murashige and Skoog medium supplemented with 2 mg/L 6-benzylaminopurine and 0.15 mg/L naphthaleneacetic acid, achieving an induction rate of 88.88%. Additionally, the study identified SA as the most effective elicitor for increasing the levels of gallic acid, protocatechuic acid, and quercitrin in the callus, with optimal concentrations of salicylic acid being 60, 40, and 60 μM, respectively. SNP at 40 μM, 80 μM, and 20 μM concentrations was identified as the best elicitor for promoting the accumulation of bergenin, chlorogenic acid, and quercetin, respectively. This study established appropriate conditions for cultivating S. stolonifera callus and identified the optimal elicitor concentrations for maximizing secondary metabolite production.

Synthesis, Structural characterization and complex impedance analysis of a novel organic-inorganic hybrid compound based on Mercury (II) chloride

The organic-inorganic hybrid compounds are promising materials due to their electro-optical and semiconducting properties. In this study, a single crystal of (C6H16N)2[HgCl4] has been synthesized and characterized using single-crystal X-ray diffraction at room temperature, SEM/EDS and complex impedance spectroscopy. The crystal structure is centrosymmetric with the monoclinic system (P21/c space group). It consists of isolated tetrahedral anions [HgCl4]2− and protonated amines (C6H16N) +. SEM/EDS analyses proved the composition of the title compound. The frequency-dependent electrical and dielectric properties were analyses using complex impedance spectroscopy in the frequency range of 10−1 Hz – 1 MHz. The Nyquist plots (-Z’’ vs Z’) was characterized by the appearance of a single semicircle arc, indicating a non-Debye type relaxation process in the (C6H16N)2[HgCl4] material. The AC conductivity followed Jonscher law, and the variation of frequency exponent s with temperature suggested that non-overlapping small polaron tunneling (NSPT) is the dominant electrical transport mechanism. So, this work will be very beneficial to the further development of the (C6H16N)2[HgCl4] compound and its potential electrical applications.

Hazard assessment and cytogenotoxic effect of different concentrations of mercury chloride sterilant using the Allium cepa assay

The Allium cepa assay represents a crucial in vivo model for evaluating the cytotoxicity and genotoxicity of substances. This study investigated the cytogenotoxicity of mercury chloride (HgCl2), a laboratory disinfectant and catalyst, using the Allium cepa assay. Mitotic slides were prepared from onion root tip cells grown on media supplemented with different concentrations of HgCl2 (0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). The slides were observed to evaluate cytogenotoxicity based on the assessment of the mitotic index, mitotic inhibition, clastogenic effect, and root length. The results showed that the concentrations used are harmful to the cell, leading to adverse impacts on the mitotic index, mitotic inhibition, root growth, and chromosome structure. Different chromosomal aberrations, such as bridge formation, fragmentation fragments, wandering chromosomes, stickiness, binucleate cells, and micronucleus formation, were detected depending on the concentration. Although lower concentrations (0.2–0.4%) had fewer effects on the cells, they still had a significant cytogenotoxic effect (p < 0.05) compared to that of the control (0.0%). The higher the concentration, the greater the effects on clastogenic changes. The abnormalities in both mitotic spread and root growth indicate that mercury chloride is cytotoxic even at low concentrations and can cause mito-depressive effects at higher concentrations. The results of this investigation can be used as a guide to guarantee sufficient safety precautions for people and organs during the regular use of HgCl2.

Effect of environmental factors on conjugative transfer of antibiotic resistance genes in aquatic settings.

Antimicrobial-resistance genes (ARGs) are spread among bacteria by horizontal gene transfer, however, the effect of environmental factors on the dynamics of the ARG in water environments has not been very well understood. In this systematic review, we employed the regression tree algorithm to identify the environmental factors that facilitate/inhibit the transfer of ARGs via conjugation in planktonic/biofilm-formed bacterial cells based on the results of past relevant research. Escherichia coli strains were the most studied genus for conjugation experiments as donor/recipient in the intra-genera category. Conversely, Pseudomonas spp., Acinetobacter spp., and Salmonella spp. were studied primarily as recipients across inter-genera bacteria. The conjugation efficiency (ce) was found to be highly dependent on the incubation period. Some antibiotics, such as nitrofurantoin (at≥0.2µg ml-1) and kanamycin (at≥9.5mg l-1) as well as metallic compounds like mercury (II) chloride (HgCl2, ≥3µmol l-1), and vanadium (III) chloride (VCl3, ≥50µmol l-1) had enhancing effect on conjugation. The highest ce value (-0.90 log10) was achieved at 15°C-19°C, with linoleic acid concentrations<8mg l-1, a recognized conjugation inhibitor. Identifying critical environmental factors affecting ARG dissemination in aquatic environments will accelerate strategies to control their proliferation and combat antibiotic resistance.