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Scientific Reports Mar 2022The purpose of this study was to test the nematicidal activity of extracts of two marine algae (Colpomenia sinuosa and Corallina mediterranea) and their synthesized...
The purpose of this study was to test the nematicidal activity of extracts of two marine algae (Colpomenia sinuosa and Corallina mediterranea) and their synthesized silver nanoparticles against root-knot nematodes (Meloidogyne incognita) that infest tomato plants. Scanning electron microscopy (SEM) revealed that nanoparticles had aggregated into anisotropic Ag particles, and transmission electron microscopy (TEM) revealed that the particle sizes were less than 40 nm. Fourier Transform Infrared Spectroscopy (FT-IR) analysis revealed that the obtained nanoparticles had a sharp absorbance between 440 and 4000 cm, with 13 distinct peaks ranging from 474 to 3915 cm. Methylene chloride extracts and nanoparticles synthesized from both algae species were used to treat M. incognita. C. sinuosa nanoparticles had the highest nematicidal activity of any treatment. Furthermore, and in contrast to other treatments, C. sinuosa nanoparticles reduced the number of nematode galls, egg-masses per root, and eggs/egg mass, while also improving plant growth parameters. C. sinuosa's methylene chloride extract was more active than C. mediterranea's, and the most effective eluent of this solvent was hexane: methylene chloride: ethyl acetate (1: 0.5: 0.5, v/v/v). When applied to M. incognita, the third fraction of this eluent was the most effective, resulting in 87.5% mortality after 12 h and 100% mortality after 24 and 72 h of exposure. The presence of seven bioactive constituents was discovered during the analysis of this fraction. In conclusion, the silver nanoparticles synthesized from C. sinuosa could be used as alternative chemical nematicides.
Topics: Animals; Antinematodal Agents; Solanum lycopersicum; Metal Nanoparticles; Methylene Chloride; Plant Extracts; Seaweed; Silver; Spectroscopy, Fourier Transform Infrared; Tylenchoidea
PubMed: 35264583
DOI: 10.1038/s41598-022-06600-1 -
Environment International Sep 2019Potentially carcinogenic hazardous air pollutants (air toxics) have been inconsistently associated with breast cancer. Whether metabolic factors modify these...
INTRODUCTION
Potentially carcinogenic hazardous air pollutants (air toxics) have been inconsistently associated with breast cancer. Whether metabolic factors modify these associations is unknown. We studied 29 non-metallic air toxics classified as mammary gland carcinogens in animal studies in relation to breast cancer risk.
METHODS
Participants included 49,718 women from the Sister Study. Census tract air toxic concentration estimates from the 2005 National Air Toxics Assessment were linked to enrollment residential addresses. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for individual air toxics were estimated using Cox regression. Body mass index (BMI) was considered a potential modifier. Relevant mixtures were identified using classification trees.
RESULTS
Over follow-up (average = 8.4 years), 2975 women were newly diagnosed with breast cancer (invasive or ductal carcinoma in situ). Several air toxics, including methylene chloride, polycyclic organic matter, propylene dichloride, and styrene, were associated with increased risk. Of these, methylene chloride was most consistently associated with risk across multiple analyses. It was associated with overall (HR = 1.21 (95%CI = 1.07-1.38)) and estrogen receptor positive (ER+) invasive breast cancer (HR = 1.28 (95%CI = 1.08-1.52)) in individual pollutant models, although no dose-response was observed. Associations were stronger among overweight/obese (vs. non-overweight/obese) women (p < 0.05) for six air toxics. The classification tree identified combinations of age, methylene chloride, BMI, and four other toxics (propylene dichloride, ethylene dibromide, ethylidene dichloride, styrene) related to overall breast cancer.
CONCLUSIONS
Some non-metallic air toxics, particularly methylene chloride, were associated with the hazard for overall and ER+ breast cancer. Overweight/obese women may be particularly susceptible to air toxics.
Topics: Air Pollutants; Air Pollution; Breast Neoplasms; Carcinogens; Cohort Studies; Female; Humans
PubMed: 31226564
DOI: 10.1016/j.envint.2019.06.007 -
Journal of Hazardous Materials Jan 2021For the first time, zinc chloride activation method was used to prepare waste paper-based activated carbon in this study. The structure, morphology, surface functional...
For the first time, zinc chloride activation method was used to prepare waste paper-based activated carbon in this study. The structure, morphology, surface functional groups and particle size distribution of the activated carbon was study using automatic specific surface area analyzer, FTIR, Boehm titration, X-ray diffraction, SEM and EDS. The specific surface area of the activated carbon is up to 1987 m/g. Cumulative pore volume is up to 2.586 cm/g, with micropore volume accounting for 92 %. Methylene blue adsorption performance results shown that the adsorbent has achieved high removal efficiency (99.65 % in 10 min, uptake = 996.5 mg/g), its maximum adsorption capacity has reached 1657 mg/g. The pH of the adsorbent was determined to explore the adsorption mechanism, its results shown that electrostatic adsorption occurs between adsorbents and adsorbents at pH higher than pH (pH = 3.2). Moreover, adsorption mechanism was studied by various isothermal models, thermodynamic models, kinetic models. Redlich-Peterson isotherm model best describes the adsorption experiment, which indicated that the adsorption follows a non-ideal and mixed adsorption mechanism. Methylene blue molecules gone into micropore was the adsorption rate-limiting step, and MB adsorption by the waste paper-based adsorbent was a spontaneous, endothermic and randomly increasing adsorption. Simulated wastewater and regeneration experiments were also used to evaluate the adsorbent's treatment capacity and economic efficiency, and these results indicated that the adsorbent has good decolorization and regeneration ability.
PubMed: 33254745
DOI: 10.1016/j.jhazmat.2020.123579 -
Photodiagnosis and Photodynamic Therapy Jun 2023Orthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased...
Photodynamic antimicrobial therapy (A-PDT) using 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB and λ640 ± 5ηm LED light in patients undertaking orthodontic treatment.
Orthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased antimicrobial resistance A-PDT has shown itself a feasible option. The aim of this investigation was to assess the efficiency of A-PDT employing 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB as a photosensitizing agent combined with red LED irradiation (λ640 ± 5 ηm) against oral biofilm of patients undertaking orthodontic treatment. Twenty-one patients agreed to participate. Four biofilm collections were carried out on brackets and gingiva around inferior central incisors; first was carried out before any treatment (Control); second followed five minutes of pre-irradiation, the third was immediately after the first AmPDT, and the last after a second AmPDT. Then, a microbiological routine for microorganism growth was carried out and, after 24-h, CFU counting was performed. There was significant difference between all groups. No significant difference was seen between Control and Photosensitizer and AmpDT1 and AmPDT2 groups. Significant differences were observed between Control and AmPDT1 and AmPDT2 groups, Photosensitizer and AmPDT1 and AmPDT2 groups. It was concluded that double AmPDT using DMBB in nano concentration and red LED was capable to meaningfully decrease the number of CFUs in orthodontic patients.
Topics: Humans; Methylene Blue; Photosensitizing Agents; Photochemotherapy; Zinc; Anti-Infective Agents
PubMed: 36907259
DOI: 10.1016/j.pdpdt.2023.103503 -
International Journal of Environmental... Sep 2022The synthesis and characterization of novel graphene oxide coupled to TiO (GO-TiO) was carried out in order to better understand the performance of this photocatalyst,...
The synthesis and characterization of novel graphene oxide coupled to TiO (GO-TiO) was carried out in order to better understand the performance of this photocatalyst, when compared to well-known TiO (P25) from Degussa. Thus, its physical-chemical characterization (FTIR, XRD, N isotherms and electrochemical measurements) describes high porosity, suitable charge and high electron mobility, which enhance pollutant degradation. In addition, the importance of the reactor set up was highlighted, testing the effect of both the irradiated area and distance between lamp and bulb solution. Under optimal conditions, the model drug methylthioninium chloride (MC) was degraded and several parameters were assessed, such as the water matrix and the catalyst reutilization, a possibility given the addition of HO. The results in terms of energy consumption compete with those attained for the treatment of this model pollutant, opening a path for further research.
Topics: Catalysis; Environmental Pollutants; Hydrogen Peroxide; Methylene Blue; Titanium; Water
PubMed: 36231173
DOI: 10.3390/ijerph191911874 -
ACS ES&T Water Aug 2021We investigated patterns of volatile organic compound (VOC) contamination in drinking water systems affected by the California 2018 Camp Fire. We performed spatial...
We investigated patterns of volatile organic compound (VOC) contamination in drinking water systems affected by the California 2018 Camp Fire. We performed spatial analysis of over 5000 water samples collected over a 17 month period by a local water utility, sampled tap water for VOCs in approximately 10% ( = 136) of standing homes, and conducted additional nontargeted chemical analysis of 10 samples. Benzene contamination was present in 29% of service connections to destroyed structures and 2% of service connections to standing homes. A spatial pattern was apparent. Tap water in standing homes 11 months after the fire contained low concentrations of benzene in 1% of samples, but methylene chloride was present in 19% of samples, including several above regulatory limits. Elevated methylene chloride was associated with greater distance from the water meter to the tap, longer stagnation time, and the presence of a destroyed structure on the service connection; it was inversely associated with certain trihalomethanes. Nontargeted analysis identified multiple combustion byproducts in the water at 2/10 homes. Our findings support the hypothesis that pyrolysis and smoke intrusion from depressurization contributed to the benzene contamination. Further research is needed to test the hypothesis that methylene chloride may be generated from the dehalogenation of disinfection byproducts stagnating in galvanized iron pipes.
PubMed: 34423333
DOI: 10.1021/acsestwater.1c00129 -
Plants (Basel, Switzerland) May 2021Based on previous investigations where bis-bibenzyls isolated from liverworts showed various biological activities (cytotoxic, antimicrobial, and antiviral), we...
Based on previous investigations where bis-bibenzyls isolated from liverworts showed various biological activities (cytotoxic, antimicrobial, and antiviral), we investigated their cytotoxic activity in several human cancer cell lines. From the methylene-chloride/methanol extract of the liverwort , three bis-bibenzyls of the perrottetin type were isolated, namely perrottetin E, 10'-hydroxyperrottetin E, and 10,10'-dihydroxyperrottetin E. The last two were found for the first time in this species. Their structures were resolved using 1D and 2D NMR, as well as by comparison with data in the literature. Cytotoxic activity of the isolated compounds was tested on three human leukemia cell lines, HL-60 (acute promyelocytic leukemia cells), U-937 (acute monocytic leukemia cells), and K-562 (human chronic myelogenous leukemia cells), as well as on human embryonal teratocarcinoma cell line (NT2/D1) and human glioblastoma cell lines A-172 and U-251, and compared to the previously isolated bis-bibenzyls (perrottetins) of similar structure. The isolated compounds exhibited modest activity against leukemia cells and significant activity against NT2/D1 and A-172. Overall, the most active cytotoxic compounds in this investigation were perrottetin E (1), isolated in this work from , and perrottetin F phenanthrene derivative (7), previously isolated from and added for a comparison of their cytotoxic activity.
PubMed: 34073157
DOI: 10.3390/plants10061063 -
Polymers Mar 2021Conformal coating is typically composed of polymeric film and is used to protect delicate electronic components such as printed-circuit boards. Without removing...
Conformal coating is typically composed of polymeric film and is used to protect delicate electronic components such as printed-circuit boards. Without removing conformal coating, it would be difficult to repair these complicated electronics. Methylene chloride, also called dichloromethane (DCM), has a widespread usage in conformal coating stripper products. The high toxicity of DCM increases human health risk when workers are exposed to DCM during the conformal coating removal processes. Therefore, the replacement of DCM would be beneficial to greatly improve the overall safety profile for workers in the electronics and coating industries. This research identified and evaluated alternative chemicals for replacing DCM used in acrylic conformal coating stripping operations. The solubility of an acrylic conformal coating was measured and characterized using Hansen solubility parameters (HSP) theory. Coating dwell time tests using various solvent blends verified the accuracy of the created HSP solubility sphere. A data processing method was also developed to identify and screen potential alternative solvent blends in terms of safety, toxicity, and cost-effectiveness. The identified safer solvent blends were demonstrated to provide equivalent stripping performance as compared to DCM based coating strippers within an acceptable cost range. The results of this research will be of value to other types of conformal coatings, such as silicone and polyurethane, where DCM is commonly used in similar coating stripping operations. By safely removing conformal coating, delicate electronics would be available for re-manufacturing, enabling a circular economy.
PubMed: 33803712
DOI: 10.3390/polym13060937 -
Toxicology Feb 2020Organophosphates (OPs) are valuable as pesticides in agriculture and for controlling deadly vector-borne illnesses; however, they are highly toxic and associated with...
Organophosphates (OPs) are valuable as pesticides in agriculture and for controlling deadly vector-borne illnesses; however, they are highly toxic and associated with many deleterious health effects in humans including long-term neurological impairments. Antidotal treatment regimens are available to combat the symptoms of acute OP toxicity, which result from the irreversible inhibition of acetylcholinesterase (AChE). However, there are no established treatments for the long-term neurological consequences of OP exposure. In addition to AChE, OPs can negatively affect multiple protein targets as well as biological processes such as axonal transport. Given the fundamental nature of axonal transport to neuronal health, we rationalized that this process might serve as a general focus area for novel therapeutic strategies against OP toxicity. In the studies described here, we employed a multi-target, phenotypic screening, and drug repurposing strategy for the evaluations of potential novel OP-treatments using a primary neuronal culture model and time-lapse live imaging microscopy. Two multi-target compounds, lithium chloride (LiCl) and methylene blue (MB), which are FDA-approved for other indications, were evaluated for their ability to prevent the negative effects of the OP, diisopropylfluorophosphate (DFP) on axonal transport. The results indicated that both LiCl and MB prevented DFP-induced impairments in anterograde and retrograde axonal transport velocities in a concentration dependent manner. While in vivo studies will be required to confirm our in vitro findings, these experiments support the potential of LiCl and MB as repurposed drugs for the treatment of the long-term neurological deficits associated with OP exposure (currently an unmet medical need).
Topics: Animals; Axonal Transport; Cerebral Cortex; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Drug Repositioning; Isoflurophate; Lithium Chloride; Male; Methylene Blue; Neurons; Phosphorylation; Primary Cell Culture; Rats; Rats, Sprague-Dawley
PubMed: 31962143
DOI: 10.1016/j.tox.2020.152379 -
Environmental Research Oct 2022Many volatile organic compounds (VOCs) are used for experiments at universities, and most of them contain benzene, toluene, ethylbenzene, xylene, and an extraction...
Many volatile organic compounds (VOCs) are used for experiments at universities, and most of them contain benzene, toluene, ethylbenzene, xylene, and an extraction solvent of dichloromethane. This study aimed to investigate the indoor concentrations of these five compounds in different locations on campus and to evaluate possible health risks for faculty members and students in a medical university. We selected 10 locations as sampling sites to conduct 4-h monitoring sessions on weekdays each season during 2019-2020. We used a 6-liter canister to collect air samples and analyzed these five VOCs via gas chromatography with a flame ionization detector. Monte Carlo simulation was performed to evaluate the carcinogenic and noncarcinogenic risks of these five VOCs. We found that dichloromethane was the most highly detected compound (median: 621.07 μg/m; range: 44.01-8523.91 μg/m), and the Department of Medicine had the highest concentration of the total of these VOCs among all of the locations (median: 5595.29 μg/m; range: 1565.67-7398.66 μg/m). The median carcinogenic risks of dichloromethane and benzene were 6.36 × 10 (95% confidence interval [CI]: 6.83 × 10-7.37 × 10) and 5.47 × 10 (95% CI: 4.03 × 10-2.42 × 10), respectively, for faculty members, and the lower risks of 3.14 × 10 (95% CI: 3.39 × 10-3.64 × 10) and 2.69 × 10 (95% CI: 1.97 × 10-1.19 × 10) were estimated for the students. The chronic noncarcinogenic risks of four VOCs were less than one, except for dichloromethane with a median hazard index of 1.92 (95% CI: 2.11 × 10-2.22 × 10). This study observed the spatial variation in the concentrations of the total of five VOCs and dichloromethane. The carcinogenic risks were classified as being at the possible level, and the noncarcinogenic risk of dichloromethane was greater than the acceptable level. Increasing local exhaust ventilation during the experiment and reducing the using amount of dichloromethane are recommended actions to reduce VOCs exposures in the medical university.
Topics: Air Pollutants; Benzene; Environmental Monitoring; Humans; Methylene Chloride; Risk Assessment; Universities; Volatile Organic Compounds
PubMed: 35697085
DOI: 10.1016/j.envres.2022.113644