Chemical Groups Research Articles

Spectroscopic, thermic and metal binding properties of commercial humic acid and leonardite

Humic acids are formed from a combination of variable chemical groups found in natural sources containing partially aromatic groups in an amorphous structure. These substances have been shown to significantly impact plant biomass, affecting nutrient distribution through direct interaction with the plant and nutrient supply and regulation through indirect interaction. The lack of a regular and repeating molecular structure in humic substances makes them challenging to determine. Humic substances used in agriculture commercially are humic and fulvic acid or combinations of both in different proportions. In our research, we used spectroscopic and thermal methods to understand the structures of commercial samples. We conducted FT-IR (Fourier Transform Infra-Red) spectroscopy to analyze the structure's bonds, thermal analysis to comprehend its thermal properties, and NMR (Nuclear Magnetic Resonance) analysis to obtain information about the carbon content. By combining, comparing, and interpreting all these methods, we can predict commercial samples' spectroscopic and thermal properties during the production stage. This can serve as a foundation for researchers studying or utilizing humic acid.

Chemical characterization of volatile organic compounds emitted by animal manure

Animal manure is considered a valuable organic fertilizer due to its important nutrient content enhancing soil fertility and plant growth in agriculture. Besides its beneficial role as fertilizer, animal manure represents a significant source of volatile organic compounds (VOCs), playing a significant role in atmospheric chemistry. Understanding the composition of VOCs Understanding VOCs from animal manure is crucial for assessing their environmental impact, as they can cause air pollution, odors, and harm to human health and ecosystems. Laboratory studies enhance field measurements by providing a precise inventory of manure emissions, addressing gaps in existing literature. Both approaches complement each other in advancing our understanding of manure emissions. In this context, we conducted an experimental study involving various animal manures (cow, horse, sheep, and goat) taken from a farm in Grignon (near Paris, France). We employed atmospheric simulation chambers within a controlled laboratory environment. The analysis of VOCs involved the combination of Proton Transfer Reaction-Quadrupole ion guide-Time-of-Flight Mass Spectrometry (PTR-QiTOF-MS) and Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS). Using PTR-QiTOF-MS, 368 compounds were detected and quantified within the manure samples. The complementary analysis by TD-GC-MS enhanced our identification of VOCs. Our findings revealed various chemical groups of VOCs, including oxygenated compounds (e.g., ethanol, cresol, acetaldehyde, etc.), nitrogenated compounds (ammonia, trimethylamine, etc.), sulfur compounds (methanethiol, dimethyl sulfide, etc.), aromatic compounds (phenols and indoles), terpenes (isoprene, D-limonene, etc.) and halogenated compounds. Cow manure exhibited the highest VOC emission fluxes, followed by goat, sheep, and horse manures. Notably, oxygenated VOCs were dominant contributors to total VOC emission fluxes in all samples. Statistical analysis highlighted the distinct nature of cow manure emissions, characterized by oxygenated compounds and nitrogenated compounds. In addition, goat manure was isolated from the other samples with high emissions of compounds having both oxygen and nitrogen atoms in their molecular formulas (e.g., CH3NO2). The experimental dataset obtained in this study provides an inventory reference for both VOCs and their emission fluxes in animal manures. Furthermore, it highlights odorant compounds and VOCs that serve as atmospheric aerosol precursor. Future studies can explore the effectiveness of various manure treatment methods to promote sustainable agriculture practices.

Grouping of short alkyl-chain branched carboxylic acids for developmental toxicity

Read-across (RAx) and grouping of chemicals into categories are well-known concepts in toxicology. Recently, ECHA proposed a grouping approach for branched-chain carboxylic acids (BCAs) including more than 60 branched-chain saturated carboxylic acids for hazard identification. Grouping was based only on structural considerations. Due to developmental effects of two members, ECHA postulated that “all short carbon chain acids … are likely reproductive and developmental toxicants”. This work analyzes available data for BCAs. The number of compounds in the group can be significantly reduced by eliminating metal and organic salts of BCAs, compounds of unknown or variable composition, and complex reaction products or biological materials (UVCB compounds). For the resulting reduced number of compounds, grouping is supported by similar physicochemical data and expected similar biotransformation. However, analysis of adverse effects for compounds in the group and mechanistic information show that BCAs, as a class, do not cause developmental effects in rats. Rather, developmental toxicity is limited to selected BCAs with specific structures that share a common mode of action (histone deacetylase inhibition). Thus, the proposed grouping is unreasonably wide and the more detailed analyses show that structural similarity alone is not sufficient for grouping branched-chain carboxylic acids for developmental toxicity.

Tunable dual-band composite metasurface absorber in the mid-infrared region based on LSPs-SPPs interaction

Mid-infrared (MIR) region includes many important fingerprint signals about of particular chemical molecules and functional groups, which is an important band for compact optical sensing system. Controlling the localized surface plasmons (LSPs) and surface plasmon polariton (SPP) modes is an effective approach to achieving perfect absorption in plasmonic metasurfaces. In this work, we systematically investigate the interaction between LSP and SPP within a composite plasmonic metasurface absorber, as well as the impact of this interaction on its absorption characteristics. The absorber achieves absorptivity 99.2 % at 2.39 μm and 98.8 % at 3.61 μm. The detailed absorption mechanism and tunability of the absorber are discussed associated with a physical model based on quantum electron dynamics (QED) theory. Our analysis also explores the effect of incident angle, identifying a Rabi splitting at 40° and 3.61 μm due to the interaction between cavity modes and LSPs, while the absorption peak at 2.39 μm experiences a redshift with an increasing angle. These peaks show minimal dependence on the polarization angles of incident light. Furthermore, we investigate the impact of the SiO2 spacer's refractive index using an admittance model, observing a redshift in the absorption peaks with an increase in refractive index. Our findings not only introduce a metasurface absorber for the MIR spectrum, applicable in sensing and detection, but also establish a foundation for further research.

Bridging scales with Machine Learning: From first principles statistical mechanics to continuum phase field computations to study order–disorder transitions in Li[formula omitted]CoO[formula omitted]

LixTMO2 (TM=Ni, Co, Mn) forms an important family of cathode materials for Li-ion batteries, whose performance is strongly governed by Li composition-dependent crystal structure and phase stability. Here, we use LixCoO2 (LCO) as a model system to benchmark a machine learning-enabled framework for bridging scales in materials physics. We focus on two scales: (a) assemblies of thousands of atoms described by density functional theory-informed statistical mechanics, and (b) continuum phase field models to study the dynamics of order–disorder transitions in LCO. Central to the scale bridging is the rigorous, quantitatively accurate, representation of the free energy density and chemical potentials of this material system by coarse-graining formation energies for specific atomic configurations. We develop active learning workflows to train recently developed integrable deep neural networks for such high-dimensional free energy density and chemical potential functions. The resulting, first principles-informed, machine learning-enabled, phase-field computations allow us to study LCO cathodes’ order–disorder transitions in terms of temperature, microstructure, and charge cycling. We highlight several insights gained to the dynamics of the phase transitions, and that have been made possible by the quantitatively rigorous scale bridging. To the best of our knowledge, such a scale bridging framework has not been previously demonstrated for LCO, or for materials systems of comparable technological interest. This approach can be expanded to other materials systems and can incorporate additional physics to that studied here.

Bio-accessibility of phenols, flavonoid and antioxidant capacity of tropical leafy vegetables through in-vitro gastro-intestinal digestion

To provide a new insight to the nutritionist and processing industries, in-vitro digestion studies of 20 tropical green leafy vegetables were conducted. The results indicated significant (P < 0.05) changes in phenolics, flavonoids and antioxidants level based on food matrix properties where the leaf extracts exhibited higher antioxidant activity than corresponding stem extracts. The most flavonoids bio-accessibility were observed in Ipomoea aquatic leaves (463.4%), Colocasia esculenta stem (335.5%), Alternanthera philoxeroides (260.7%). The transformation of phenolic compounds during in-vitro digestion may lead to different structural forms possessing different chemical properties and functions. Compared to fresh state, except for Trigonella foenum graecum, Ipomoea aquatica stem, all vegetables exhibited decrease in antioxidant activity (DPPH) value (4.7%–76.9%), nine vegetables exhibited a decrease in antioxidant activity (ABTS) value (3.01%–22.8%) and except for Amarantus cruentas, all vegetables exhibited decrease in FRAP value (15.29%–85.24%). Only four vegetables (Colocasia esculenta stem and leaf, Amaranthus cruentas and Murraya koenigii) had shown decrease (1.7%–13.2%) and rest 16 vegetables followed 9.6%–314.13% increase in β-carotene bleaching. Interestingly, all vegetables displayed sharp increase in Super Oxide Dismutage (SOD) value (94.99%–174.78%) after duodenal phase even significant changes in phenolic content and flavonoid contents were observed. Correlation analysis showed weak correlation between phenolic content with antioxidant activity in successive gastric and duodenal phase.

Lower micromolar activity of the antifungal imidazoles on the bacterial-type bifunctional aldehyde/alcohol dehydrogenase (AdhE) in Cryptosporidium parvum and in vitro efficacy against the zoonotic parasite

Cryptosporidium parvum is a waterborne and foodborne zoonotic protozoan parasite, a causative agent of moderate to severe diarrheal diseases in humans and animals. However, fully effective treatments are unavailable for medical and veterinary uses. There is a need to explore new drug targets for potential development of new therapeutics. Because C. parvum relies on anaerobic metabolism to produce ATP, fermentative enzymes in this parasite are attractive targets for exploration. In this study, we investigated the ethanol-fermentation in the parasite and characterized the basic biochemical features of a bacterial-type bifunctional aldehyde/alcohol dehydrogenase, namely CpAdhE. We also screened 3892 chemical entries from three libraries and identified 14 compounds showing >50% inhibition on the enzyme activity of CpAdhE. Intriguingly, antifungal imidazoles and unsaturated fatty acids are the two major chemical groups among the top hits. We further characterized the inhibitory kinetics of selected imidazoles and unsaturated fatty acids on CpAdhE. These compounds displayed lower micromolar activities on CpAdhE (i.e., IC50 values ranging from 0.88 to 11.02 μM for imidazoles and 8.93 to 35.33 μM for unsaturated fatty acids). Finally, we evaluated the in vitro anti-cryptosporidial efficacies and cytotoxicity of three imidazoles (i.e., tioconazole, miconazole and isoconazole). The three antifungal imidazoles exhibited lower micromolar efficacies against the growth of C. parvum in vitro (EC50 values ranging from 4.85 to 10.41 μM and selectivity indices ranging from 5.19 to 10.95). The results provide a proof-of-concept data to support that imidazoles are worth being further investigated for potential development of anti-cryptosporidial therapeutics.

Chemical hazard assessment toward safer electrolytes for lithium-ion batteries.

Commercialization of rechargeable lithium-ion (Li-ion) batteries has revolutionized the design of portable electronic devices and is facilitating the current transition to electric vehicles. The technological specifications of Li-ion batteries continue to evolve through the introduction of various high-risk liquid electrolyte chemicals, yet critical evaluation of the physical, environmental, and human health hazards of these substances is lacking. Using the GreenScreen for Safer Chemicals approach, we conducted a chemical hazard assessment (CHA) of 103 electrolyte chemicals categorized into seven chemical groups: salts, carbonates, esters, ethers, sulfoxides-sulfites-sulfones, overcharge protection additives, and flame-retardant additives. To minimize data gaps, we focused on six toxicity and hazard data sources, including three empirical and three nonempirical predictive data sources. Furthermore, we investigated the structural similarities among selected electrolyte chemicals using the ChemMine tool and the simplified molecular input line entry systeminputs from PubChem to evaluate whether chemicals with similar structures exhibit similar toxicity. The results demonstrate that salts, overcharge protection additives, and flame-retardant additives contain the most toxic components in the electrolyte solutions. Furthermore, carbonates, esters, and ethers account for most flammability hazards in Li-ion batteries. This study supports the complementary use of quantitative structure-activity relationship modelsto minimize data gaps and inconsistencies in CHA. Integr Environ Assess Manag 2024;20:2231-2244. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Effect of reduced graphene oxide on vulcanization of polydimethylsiloxane composites

AbstractThis research aims to investigate the effect of reduced graphene oxide (rGO) on the kinetics of addition vulcanization in polydimethylsiloxane (PDMS) elastomers. For this purpose, the synthesis of graphene oxide (GO) and silane‐grafted GO followed by chemical reduction of particles was conducted to prepare rGOs with different surface chemistry. Particles were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, x‐ray diffraction, scanning electron microscopy, and energy‐dispersive x‐ray analysis. Composites of PDMS containing these particles were prepared by solution mixing, and vulcanization of composites was investigated using differential scanning calorimetry. Results showed that the rate and degree of vulcanization reaction increase up to a critical concentration of particles and then decrease afterward. This behavior was attributed to the catalytic effect of chemical groups on the surface of rGOs, whereas the reverse behavior above the critical concentration was correlated to the immobilization of trapped rubber in the network of particles. Grafting graphene oxide by a long alkyl‐chain silane covered these chemical groups, suppressed the catalytic effect, improved the dispersion of particles, and shifted the critical concentration lower. The critical concentration was correlated to the electrical percolation threshold of particles and confirmed by the solvent swelling method. It was also shown that rGO can itself act as the catalyst for the vulcanization of PDMS with no need for platinum. As the dynamic‐mechanical‐thermal analysis showed, the PDMS composites containing 0.75 wt% of particles did not vulcanize properly. However, composites containing fewer particles were vulcanized.Highlights Reduced graphene oxide affects additional vulcanization of PDMS. Below a critical loading, rGO accelerates vulcanization by a catalytic effect. Above critical loading, rGO decelerates vulcanization by a networking effect. Surface groups of rGO control catalytic and networking mechanisms. Silane modification of rGO affects interfacial behavior, thus critical loading.

High plasma magnesium and phosphorus levels and their correlation with struvite urolithiasis in buffaloes

BackgroundUrolithiasis is a common urinary tract disease in buffaloes, almost exclusively affects young males, and has significant economic and production impacts. We have investigated hemato-biochemical and urinary changes in an attempt to deduce their correlation with struvite urolithiasis in buffaloes. MethodsTen male buffalo calves with obstructive urolithiasis were used. Blood samples were used for hematology and elemental analysis. Urine samples were used for physico-chemical examination, microscopy, and elemental analysis. Uroliths were subjected to chemical functional group determination using the FTIR spectroscopy. ResultsThe mean neutrophil, leukocyte, and neutrophil-to-lymphocyte ratio was significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. The mean blood calcium and magnesium concentrations were significantly (p < 0.05) lower and higher in urolithic buffaloes than in healthy controls, respectively. Mean blood phosphorus concentration and calcium-phosphorus ratio were found to be non-significantly (p > 0.05) higher and lower in urolithic buffaloes than in healthy controls, respectively. The urine pH was highly alkaline. Multiple prismatic lid-shaped crystals, along with erythrocytes, leukocytes, and epithelial cells, were found in urine. The mean urinary magnesium and phosphorus concentrations were non-significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. A positive correlation of magnesium (r = 0.864, p = 0.001) and phosphorus (r = 0.849, p = 0.002) concentrations between the blood and urine was observed in urolithic buffaloes. The FTIR spectra of uroliths were similar to those of magnesium ammonium phosphate hexahydrate, MgNH4PO4·6H2O or struvite. ConclusionThe findings suggest that high plasma magnesium and phosphorus concentrations have a positive correlation with struvite urolithiasis in buffaloes.

Renal toxicity of Aconitum plants? A study based on a new mass spectrometry scanning strategy and computer virtual screening.

Radix Aconiti Lateralis (Fuzi), a mono-herbal preparation of Aconitum herbs in the genus Aconitum, is commonly used in traditional Chinese medicine (TCM) to treat critical illnesses. The curative effect of Fuzi is remarkable. However, the toxic effects of Fuzi are still a key clinical focus, and the substances inducing nephrotoxicity are still unclear. Therefore, this study proposes a research model combining "in vitro and in vivo component mining-virtual multi-target screening-active component prediction-literature verification" to screen potential nephrotoxic substances rapidly. The UHPLC-Q-Exactive-Orbitrap MS analysis method was used for the correlation analysis of Fuzi's in vitro-in vivo chemical substance groups. On this basis, the key targets of nephrotoxicity were screened by combining online disease databases and a protein-protein interaction (PPI) network. The computer screening technique was used to verify the binding mode and affinity of Fuzi's components with nephrotoxic targets. Finally, the potential material basis of Fuzi-induced nephrotoxicity was screened. Eighty-one Fuzi components were identified. Among them, 35 components were absorbed into the blood. Based on the network biology method, 21 important chemical components and three potential key targets were screened. Computer virtual screening revealed that mesaconine, benzoylaconine, aconitine, deoxyaconitine, hypaconitine, benzoylhypaconine, benzoylmesaconine, and hypaconitine may be potential nephrotoxic substances of Fuzi. Fuzi may interact with multiple components and targets in the process of inducing nephrotoxicity. In the future, experiments can be designed to explore further. This study provides a reference for screening Fuzi nephrotoxic components and has certain significance for the safe use of Fuzi.

Raman spectroscopic comparison of zearalenone and its derivatives for non-destructive rapid detection

Raman spectroscopy is used to investigate the absorption and dispersion of zearalenone (ZEN) and its derivatives. The C=C stretching vibration modes of ZEN and zearalenol (ZENOL) were appeared at 975–990 cm−1. The C=O vibration mode was present at 1680–1690 cm−1 for ZEN and zearalanone (ZAN), but it was absent for ZENOL and zearalanol (ZANOL) which have –OH group instead of –C=O group in ZEN and ZAN molecular structures. On the basis of this characterization, Raman spectra of specific chemical groups and linkages corresponding to the structural difference of ZEN and its derivatives were identified. These results indicated that Raman spectroscopy can apply for the identification of ZEN and its derivatives and has a potential for the non-destructive rapid detection of these compounds in food.

A pharmacovigilance study of drug-reduced male semen quality based on the Food and Drug Administration adverse event reporting system database.

Real-world big data studies on drug-reduced male semen quality are few and far between, with most studies based on animal trials, small scale retrospective studies, or a limited number of pre-market clinical trials. This study aimed to identify culprit drugs that reduced male semen quality based on the United States Food and Drug Administration adverse event reporting system. The Medical Dictionary for Regulatory Activities preferred terms and standardized Medical Dictionary for Regulatory Activities queries were used to define reduced male semen quality. Adverse events related to drug-reduced male semen quality were then analyzed by disproportionality analysis using the United States Food and Drug Administration adverse event reporting system data between 2004 and 2023. At the preferred term level, 59 drugs with risk signals were detected to be associated with drug-reduced male semen quality, with the three most frequently reported second-level Anatomical Therapeutic Chemical groups being antineoplastic agents (n=16, 27.12%), psychoanaleptics (n=9, 15.25%), and psycholeptics (n=6, 10.17%). At the standardized Medical Dictionary for Regulatory Activities queries level, the five drugs with the greatest number of cases were finasteride (845 cases, IC025=7.72), dutasteride (163 cases, IC025=7.22), tamsulosin (148 cases, IC025=5.99), testosterone (101 cases, IC025=4.08), and valproic acid (54 cases, IC025=2.44). Additionally, clinical information about drug-reduced male semen quality is absent from the Summary of Product Characteristics of 41 drugs in our study. Using the United States Food and Drug Administration adverse event reporting system database, we offer a list of drugs with risk signals for reducing male semen quality. In the future, there is still a need for more studies on drugs whose effects on male semen quality are not fully understood.

Morphological, TGA, and FTIR on Rigid Polyurethane Composite Laminated with Untreated and Treated Bamboo Fiber Roof Insulation

The performance of roof insulation such as polyurethane decreased due to problems such as insufficient absorption and poor thermal insulation performance, especially during rainstorms. The aims of this study are to investigate the physical property and its potential reinforced material such as rigid polyurethane doped with treated and untreated bamboo fiber composite (RPU-BF) at different ratios of 0, 25, 30, 35, and 40% of bamboo fibers as an insulation material for roof applications. The bamboo fibers were treated by using silane coupling agent treatment. The rigid polyurethane composite samples were prepared and then laminated bamboo fiber to overcome the sound problem in roofs. The physical characterization was investigated by Water Contact Angle (WCA), the morphological by Scanning Electron Microscopy (SEM), Thermo-gravimetric Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FTIR) Analysis. The results showed that the treated bamboo fiber had a 192.5° water contact angle as a super hydrophobic property due to the presence of the chemical bonds Si-O-Si and Si-O-C in the silane coupling agent treatment. The morphology showed that 30% ratios of RPU-BF-T30 give the smallest pore diameter size. The peak of thermal degradation temperature of untreated and treated bamboo fiber was increased from 320°C to 350 °C with a weight loss of 80% to 50%. The treated bamboo fiber exhibited peaks at 3010–3040 cm-1 were associated with stronger Si-O-Si bonding, indicating the formation of new chemical bonds between bamboo fiber and silane coupling agent due to the ester bond from the cellulose, lignin, and hemicellulose. Thus, there was a similar trend peak in the functional chemical group in the FTIR spectrum of the RPU-BF composite. This result shows that RPU-BF composite had the potential of the optimum ratio of bamboo fiber as an insulation material for local communities and beneficial to the bamboo industry.

Effect of ohmic heating on the structure and properties of flexible multilayer packaging

Food-packaging-processing interactions define packaging materials' performance properties and product quality. This study evaluated the effect of ohmic heating (OH) processing and different food simulants on the properties of four multilayer flexible packaging materials (PETmet/PE, PETmet/PP, PET/Al/PE, and PET/Al/PA/PP). OH treatment was applied to the sealed packages containing the food simulants using a voltage gradient of 3.7 V/cm at a frequency of 20 kHz, resulting in a thermal process of at 80 °C for 1 min. The structure and performance of the different packages were then evaluated. The materials did not show changes in chemical groups nor thermal properties. However, the simulant-packaging-processing interaction resulted in changes in crystallinity, morphology, mechanical and barrier properties (water and oxygen), especially for metallized films in contact with acidic food simulants. The results indicate that although OH resulted in changes in packaging materials, these materials can be used under the conditions applied in this study.

Evaluating associations of bisphenol and phthalate exposure with time to pregnancy and subfecundity in a New York City pregnancy cohort

It is important to understand the impact of consumer chemical exposure and fecundity, a couple's measure of probability of successful conception, given approximately 15% of couples experience infertility. Prior research has generally found null associations between bisphenol and phthalate exposure and fecundability, measured via time to pregnancy (TTP). However, this research has not been updated with current chemical exposures and have often lacked diversity in their study populations. We evaluated the associations between common bisphenol and phthalate chemical exposure groups and TTP as well as subfecundity (TTP>12 months) in the New York University Children's Health Study, a diverse pregnancy cohort from 2016 onward. Using first-trimester spot-urine samples to measure chemical exposure and self-reported TTP from first-trimester questionnaires, we observed a significant adverse association between total bisphenol exposure and certain phthalate groups on TTP and odds of subfecundity. Furthermore, in a mixtures analysis to explore the joint effects of the chemical groups on the outcomes, we found evidence of a potential interaction between total bisphenol exposure and low-molecular weight phthalates on TTP. Future research should continue to update our knowledge regarding the complex and potentially interacting effects of these chemicals on reproductive health.

Comparative analysis of Rhipicephalus microplus (Canestrini, 1888)infestation in pure breed (Hereford) and cross breed (Braford) cattle herds subjected to the same chemical treatments.

The aim of this work was to analyze the R. microplus (Canestrini, 1888)infestation in two bovine herds with different degrees of natural resistance (i.e., Hereford and Braford) to ticks subjected to an identical chemical treatment scheme to ticks at the same farm, to demonstrate the impact on tick control of the incorporation of a more resistant bovine breed. Two groups of ten Hereford and Braford cows each were subjected to eleven chemical treatments between August 2022 and October 2023 (four fluazuron, two fipronil 1%, one ivermectin 3.15% and four immersion in a dipping vat with a combination of cypermethrin 10% and ethion 40%). Tick population was shown to be susceptible to ivermectin, fluazuron and the mix cypermethrin 10%-ethion 40% and resistant to fipronil according to in vitro tests. Tick infestation was significantly greater in the Hereford cows than in the Braford cows. Tick infestation in both Hereford and Braford breeds was similar when treatment with functional drugs was applied, but when a block of the treatments was done with drugs with decreased functionality due to resistance (i.e. fipronil), treatment failure was manifested more strongly in the most susceptible breed. The incorporation of cattle breeds with moderate or high resistance to R. microplus is instrumental to optimize the efficacy and sustainability of chemical control of ticks in a scenario where resistance to one or more chemical groups is almost ubiquitous, because it favors the biological control of this parasite.

Occurrence and Consequences of Matrix Effects in Simultaneous Multi-class LC-MS/MS Determination of Pesticides, Pharmaceuticals and Perfluoroalkylsubstances in Different Types of Groundwater

Matrix effects are a recent remarkable feature in quantitative LC-MS/MS analysis. In this work, the matrix effects of a multiclass mixture of 46 analytes - pesticides, pharmaceuticals and perfluoroalkylsubstances in different types of natural groundwater were studied. Groundwater samples were spiked with different standards from different chemical groups and determined by direct injection and liquid chromatography coupled to tandem mass spectrometry. Matrix effects were assessed by matrix factors calculated using the slope ratio technique. Groundwater samples were sampled in different boreholes in several places in Slovakia. The relationship with the various detected inorganic parameters was investigated and discussed. Most of the studied analytes showed negative matrix effects. Some analytes showed weak negative or positive matrix effects. The results show that average matrix factors obtained from different sampling sites are not a reliable tool and matrix effects need to be monitored depending on the sampling location. Only weak or no correlation of the matrix factors with the determined inorganic parameters was found. Geochemical composition of boreholes samples was determined and the differences in the macrochemical composition of the samples was evaluated. Model samples of ultrapure water enriched with NaCl, Na2CO3 and NaNO3 at various concentration levels were tested and the matrix effects were not observed. Other content of sample than cations Na+ were responsible for the matrix effects. It was found that the most affected compounds are sulfamethoxazole, sulfadiazine, metamitron, chloridazon and also caffeine. The results show that the detailed study is suitable as a tool for a deeper understanding of matrix effects in different types of groundwater. The proper ground water sample must be selected for reliable results of quantitative analysis.Graphical

Macroinvertebrate communities respond strongly but non-specifically to a toxicity gradient derived by effect-based methods

Chemical pollution is one of the most important threats to freshwater ecosystems. The plethora of potentially occurring chemicals and their effects in complex mixtures challenge standard monitoring methods. Effect-based methods (EBMs) are proposed as complementary tools for the assessment of chemical pollution and toxic effects. To investigate the effects of chemical pollution, the ecological relevance of EBMs and the potential of macroinvertebrates as toxicity-specific bioindicators, ecological and ecotoxicological data were linked. Baseline toxicity, mutagenicity, dioxin-like and estrogenic activity of water and sediment samples from 30 river sites in central Germany were quantified with four in vitro bioassays. The responses of macroinvertebrate communities at these sites were assessed by calculating 16 taxonomic and functional metrics and by investigating changes in the taxonomic and trait composition. Principal component analysis revealed an increase in toxicity along a joint gradient of chemicals with different modes of action. This toxicity gradient was associated with a decrease in biodiversity and ecological quality, as well as significant changes in taxonomic and functional composition. The strength of the effects suggested a strong impact of chemical pollution and underlined the suitability of EBMs in detecting ecological relevant effects. However, the metrics, taxa, and traits associated with vulnerability or tolerance to toxicity were found to also respond to other stressors in previous studies and thus may have only a low potential as toxicity-specific bioindicators. Because macroinvertebrates respond integratively to all present stressors, linking both ecological and environmental monitoring is necessary to investigate the overall effects but also isolate individual stressors. EBMs have a high potential to separate the toxicity of chemical mixtures from other stressors in a multiple stressor scenario, as well as identifying the presence of chemical groups with specific modes of action.

Unveiling Anisomeles malabarica (L.) R.Br Ex Sims: Extracting Bioactive Compounds for Antibacterial And Antioxidant Activities

The allopathic herb Anisomeles malabarica (L.) R.Br ex Sims is a member of the Lamiaceae family of mints. This investigation aims to determine whether the acetone extract of Anisomeles malabarica (L.) R.Br ex Sims leaves exhibit in vitro antibacterial activity. The results of the phytochemical study showed that steroids, flavonoids, phenols, terpenoids, quinones, and saponin were present. TLC detected and separated potential chemical components present in the extract. The GCMS revealed the presence of volatile substances, and the LC-MS disclosed the existence of non-volatile substances based on the highest peak. The FT-IR spectrum data revealed the chemical compound's potential functional groups in the A.malabarica acetone extract. DPPH free radical scavenging showed that the acetone extract of conc. 40mg/ml, 60mg/ml, 80mg/ml and 100mg/ml possessed great antioxidant ability compared to standard. Escherichia coli, Bacillus subtilis, Bacillus cereus, and Klebsiella pneumonia were tested for antibacterial activity using the unpolished well diffusion technique. E. coli and B. subtilis were inhibited more effectively by the extract in conc.50μg/ml, 75μg/ml and 100μg/ml.