Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.437
Filtrar
1.
Sci Rep ; 14(1): 14143, 2024 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898054

RESUMO

Dental fear and anxiety (DFA) is known as an immense challenge in oral healthcare, which can result in compromised oral health, pain, and uncomfortable treatment. The objective of this study was to analyze the effect of essential-oil vaporization on acute anxiety of patients in dental practices. Four dental practices used five weekly cycles of vaporization with each scent: Orange (Citrus sinensis), Swiss Pine (Pinus cembra), Good Mood (blended essential oils: Citrus sinensis, Citrus aurantifolia, Citrus limon, Osmanthus fragrance (5%)), Forest Walk (blended essential oils: Abies grandis, Pinus cembra, Myrtus communis c. t. 1,8-cineol, Abies alba, Citrus paradisi, Abies sibirica, Pseudotsuga menziesii, Vetiveria zizanoides), and water. Acute anxiety was the primary outcome (state-trait-anxiety inventory (STAI-S)). Secondary outcomes were trait anxiety (STAI-T), dental anxiety (Kleinknecht dental fear survey), and pain perception in treatment (numeric rating scale). Across all patients (n = 486), STAI-S was slightly higher in the control group (40.7 ± 11.6) than in the intervention groups (38.4 ± 10.5). Post-hoc analyses revealed that the effect is only robust for the subgroup of female patients (n = 296, p = 0.044). We also conducted a post-hoc additional analysis on a subpopulation with an increased level of STAI-T ≥ 42 (n = 131 patients). For this group the difference in acute anxiety between the control group (51.1 ± 11.9, n = 30) vs. the intervention groups (46.8 ± 9.6, n = 118) was significant (T = 4.39, p = 0.0379). The results of the study indicate a promising potential of essential-oil vaporization to alleviate dental anxiety, particularly in the subgroups of patients with a high level of trait anxiety, and particularly in female patients. The calming effects of the essential-oil vaporization were also highlighted by the anecdotical statements of the dental-practice staff. The anxiety-reducing role of essential-oil vaporization alone and as one part of combined techniques to counter DFA should be further explored using multi-perspective methodological approaches in research.


Assuntos
Ansiedade ao Tratamento Odontológico , Óleos Voláteis , Humanos , Feminino , Masculino , Óleos Voláteis/uso terapêutico , Adulto , Ansiedade ao Tratamento Odontológico/psicologia , Pessoa de Meia-Idade , Aromaterapia/métodos , Volatilização , Método Simples-Cego , Adulto Jovem
2.
Ecotoxicol Environ Saf ; 280: 116545, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38850709

RESUMO

Isoprenoid metabolism and its derivatives took part in photosynthesis, growth regulation, signal transduction, and plant defense to biotic and abiotic stresses. However, how aluminum (Al) stress affects the isoprenoid metabolism and whether isoprenoid metabolism plays a vital role in the Citrus plants in coping with Al stress remain unclear. In this study, we reported that Al-treatment-induced alternation in the volatilization rate of monoterpenes (α-pinene, ß-pinene, limonene, α-terpinene, γ-terpinene and 3-carene) and isoprene were different between Citrus sinensis (Al-tolerant) and C. grandis (Al-sensitive) leaves. The Al-induced decrease of CO2 assimilation, maximum quantum yield of primary PSII photochemistry (Fv/Fm), the lower contents of glucose and starch, and the lowered activities of enzymes involved in the mevalonic acid (MVA) pathway and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway might account for the different volatilization rate of isoprenoids. Furthermore, the altered transcript levels of genes related to isoprenoid precursors and/or derivatives metabolism, such as geranyl diphosphate (GPP) synthase (GPPS) in GPP biosynthesis, geranylgeranyl diphosphate synthase (GGPPS), chlorophyll synthase (CHS) and GGPP reductase (GGPPR) in chlorophyll biosynthesis, limonene synthase (LS) and α-pinene synthase (APS) in limonene and α-pinene synthesis, respectively, might be responsible for the different contents of corresponding products in C. grandis and C. sinensis. Our data suggested that isoprenoid metabolism was involved in Al tolerance response in Citrus, and the alternation of some branches of isoprenoid metabolism could confer different Al-tolerance to Citrus species.


Assuntos
Alumínio , Monoterpenos Bicíclicos , Citrus , Limoneno , Fotossíntese , Folhas de Planta , Terpenos , Alumínio/toxicidade , Terpenos/metabolismo , Citrus/metabolismo , Citrus/efeitos dos fármacos , Limoneno/metabolismo , Fotossíntese/efeitos dos fármacos , Monoterpenos Bicíclicos/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Monoterpenos/metabolismo , Hemiterpenos/metabolismo , Cicloexenos/metabolismo , Fosfatos Açúcares/metabolismo , Butadienos/metabolismo , Eritritol/análogos & derivados , Eritritol/metabolismo , Ácido Mevalônico/metabolismo , Monoterpenos Cicloexânicos , Citrus sinensis/metabolismo , Citrus sinensis/efeitos dos fármacos , Citrus sinensis/genética , Clorofila/metabolismo , Alquil e Aril Transferases/metabolismo , Alquil e Aril Transferases/genética , Volatilização
3.
Chemosphere ; 361: 142551, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38852280

RESUMO

The fate of volatile organic compounds (VOC) vapors in the unsaturated zone is the basis for evaluating the natural attenuation potential and vapor intrusion risk. Microcosm and column experiments were conducted to study the effects chemical speciation and soil types/properties on the fate of petroleum VOCs in unsaturated zone. The biodegradation and total attenuation rates of the seven VOCs obtained by microcosm experiments in black soil and yellow earth were also generally higher than those in floodplain soil, lateritic red earth, and quartz sand. The VOC vapors in floodplain soil, lateritic red earth, and quartz sand showed slow total attenuation rates (<0.3 d-1). N-pentane, methylcyclopentane, and methylcyclohexane showed lower biodegradation rates than octane and three monoaromatic hydrocarbons. Volatilization into the atmosphere and biodegradation are two important natural attenuation paths for VOCs in unsaturated soil columns. The volatilization loss fractions of different volatile hydrocarbons in all five unsaturated soils were generally in the order: n-pentane (93.5%-97.8%) > methylcyclopentane (77.2%-85.5%) > methylcyclohexane (53.5%-69.2%) > benzene (17.1%-73.3%) > toluene (0-45.7%) > octane (1.9%-34.2%) > m-xylene (0-5.7%). The fractions by volatilization into the atmosphere of all seven hydrocarbons in quartz sand, lateritic red earth, and floodplain soil were close and higher compared to the yellow earth and black soil. Overall, this study illustrated the important roles chemical speciation and soil properties in determining the vapor-phase transport and natural attenuation of VOCs in the unsaturated zone.


Assuntos
Biodegradação Ambiental , Petróleo , Poluentes do Solo , Solo , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Petróleo/análise , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/química , Adsorção , Volatilização , Pentanos/química , Pentanos/análise , Octanos/química , Tolueno/química , Tolueno/análise , Benzeno/análise , Benzeno/química
4.
Environ Sci Technol ; 58(27): 12062-12072, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38917340

RESUMO

Dicamba is a semivolatile herbicide that has caused widespread unintentional damage to vegetation due to its volatilization from genetically engineered dicamba-tolerant crops. Strategies to reduce dicamba volatilization rely on the use of formulations containing amines, which deprotonate dicamba to generate a nonvolatile anion in aqueous solution. Dicamba volatilization in the field is also expected to occur after aqueous spray droplets dry to produce a residue; however, dicamba speciation in this phase is poorly understood. We applied Fourier transform infrared (FTIR) spectroscopy to evaluate dicamba protonation state in dried dicamba-amine residues. We first demonstrated that commercially relevant amines such as diglycolamine (DGA) and n,n-bis(3-aminopropyl)methylamine (BAPMA) fully deprotonated dicamba when applied at an equimolar molar ratio, while dimethylamine (DMA) allowed neutral dicamba to remain detectable, which corresponded to greater dicamba volatilization. Expanding the amines tested, we determined that dicamba speciation in the residues was unrelated to solution-phase amine pKa, but instead was affected by other amine characteristics (i.e., number of hydrogen bonding sites) that also correlated with greater dicamba volatilization. Finally, we characterized dicamba-amine residues containing an additional component (i.e., the herbicide S-metolachlor registered for use alongside dicamba) to investigate dicamba speciation in a more complex chemical environment encountered in field applications.


Assuntos
Aminas , Dicamba , Herbicidas , Aminas/química , Dicamba/química , Volatilização , Herbicidas/química , Espectroscopia de Infravermelho com Transformada de Fourier
5.
Environ Sci Technol ; 58(20): 8835-8845, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38722766

RESUMO

Volatile methyl siloxanes (VMS) are a group of organosilicon compounds of interest because of their potential health effects, their ability to form secondary organic aerosols, and their use as tracer compounds. VMS are emitted in the gas-phase from using consumer and personal care products, including deodorants, lotions, and hair conditioners. Because of this emission route, airborne concentrations are expected to increase with population density, although there are few studies in large urban centers. Here, we report summertime concentrations and daily variations of VMS congeners measured in New York City. Median concentrations of the 6 studied congeners, D3 (20 ng m-3), D4 (57 ng m-3), D5 (230 ng m-3), D6 (11 ng m-3), L5 (2.5 ng m-3), and L7 (1.3 ng m-3) are among the highest reported outdoor concentrations in the literature to date. Average congener ratios of D5:D4 and D5:D6 were consistent with previously reported emissions ratios, suggesting that concentrations were dominated by local emissions. Measured concentrations agree with previously published results from a Community Multiscale Air Quality model and support commonly accepted emissions rates for D4, D5, and D6 of 32.8, 135, and 6.1 mg per capita per day. Concentrations of D4, D5, D6, L5, and L7 and total VMS were significantly lower during the day than during the night, consistent with daytime oxidation reactivity. Concentrations of D3 did not show the same diurnal trend but exhibited a strong directional dependence, suggesting that it may be emitted by industrial point sources in the area rather than personal care product use. Concentrations of all congeners had large temporal variations but showed relatively weak relationships with wind speed, temperature, and mixing height.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Siloxanas , Cidade de Nova Iorque , Siloxanas/análise , Poluentes Atmosféricos/análise , Indústrias , Humanos , Volatilização , Estações do Ano , Cosméticos/análise , Compostos Orgânicos Voláteis/análise
6.
Arch Microbiol ; 206(6): 246, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38704767

RESUMO

Shake-flask culture, an aerobic submerged culture, has been used in various applications involving cell cultivation. However, it is not designed for forced aeration. Hence, this study aimed to develop a small-scale submerged shaking culture system enabling forced aeration into the medium. A forced aeration control system for multiple vessels allows shaking, suppresses volatilization, and is attachable externally to existing shaking tables. Using a specially developed plug, medium volatilization was reduced to less than 10%, even after 45 h of continuous aeration (~ 60 mL/min of dry air) in a 50 mL working volume. Escherichia coli IFO3301 cultivation with aeration was completed within a shorter period than that without aeration, with a 35% reduction in the time-to-reach maximum bacterial concentration (26.5 g-dry cell/L) and a 1.25-fold increase in maximum concentration. The maximum bacterial concentration achieved with aeration was identical to that obtained using the Erlenmeyer flask, with a 65% reduction in the time required to reach it.


Assuntos
Meios de Cultura , Escherichia coli , Escherichia coli/crescimento & desenvolvimento , Volatilização , Meios de Cultura/química , Reatores Biológicos/microbiologia , Técnicas Bacteriológicas/métodos
7.
Environ Res ; 256: 119247, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38815719

RESUMO

The incorporation of organic groups into sol-gel silica materials is known to have a noticeable impact on the properties and structure of the resulting xerogels due to the combination of the properties inherent to the organic fragments (functionality and flexibility) with the mechanical and structural stability of the inorganic matrix. However, the reduction of the inorganic content in the materials could be detrimental to their thermal stability properties, limiting the range of their potential applications. Therefore, this work aims to evaluate the thermal stability of hybrid inorganic-organic silica xerogels prepared from mixtures of tetraethoxysilane and organochlorinated triethoxysilane precursors. To this end, a series of four materials with a molar percentage of organochlorinated precursor fixed at 10%, but differing in the type of organic group (chloroalkyls varying in the alkyl-chain length and chlorophenyl), has been selected as model case study. The gases and vapors released during the thermal decomposition of the samples under N2 atmosphere have been analyzed and their components determined and quantified using a thermogravimetric analyzer coupled to a Fourier-transform infrared spectrophotometer and to a gas chromatography-mass spectrometry unit. These analyses have allowed to identify up to three different thermal events for the pyrolysis of the organochlorinated xerogel materials and to elucidate the reaction pathways associated with such processes. These mechanisms have been found to be strongly dependent on the specific nature of the organic group.


Assuntos
Dióxido de Silício , Dióxido de Silício/química , Adsorção , Hidrocarbonetos Clorados/química , Géis/química , Poluentes Atmosféricos/química , Poluentes Atmosféricos/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Temperatura Alta , Volatilização , Cromatografia Gasosa-Espectrometria de Massas
8.
Chemosphere ; 359: 142257, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38719116

RESUMO

The accurate prediction of standard vaporization enthalpy (ΔvapHm°) for volatile organic compounds (VOCs) is of paramount importance in environmental chemistry, industrial applications and regulatory compliance. To overcome traditional experimental methods for predicting ΔvapHm° of VOCs, machine learning (ML) models enable a high-throughput, cost-effective property estimation. But despite a rising momentum, existing ML algorithms still present limitations in prediction accuracy and broad chemical applications. In this work, we present a data driven, explainable supervised ML model to predict ΔvapHm° of VOCs. The model was built on an established experimental database of 2410 unique molecules and 223 VOCs categorized by chemical groups. Using supervised ML regression algorithms, the Random Forest successfully predicted VOCs' ΔvapHm° with a mean absolute error of 3.02 kJ mol-1 and a 95% test score. The model was successfully validated through the prediction of ΔvapHm° for a known database of VOCs and through molecular group hold-out tests. Through chemical feature importance analysis, this explainable model revealed that VOC polarizability, connectivity indexes and electrotopological state are key for the model's prediction accuracy. We thus present a replicable and explainable model, which can be further expanded towards the prediction of other thermodynamic properties of VOCs.


Assuntos
Aprendizado de Máquina , Termodinâmica , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Volatilização , Algoritmos , Modelos Químicos
9.
Anal Chem ; 96(22): 8886-8892, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38771107

RESUMO

Illegal addition of drugs is common but seriously threatens public health safety. Conventional mass spectrometry methods are difficult to realize direct analysis of drugs existing in some complex matrices such as seawater or soil due to the ion suppression effect and contamination to MS parts caused by nonvolatile salts. In this work, a novel crystallization and solvent evaporation ionization mass spectrometry (CSEI-MS) method was constructed and developed to achieve rapid desalting detection. CSEI only consists of a heated plate and a nebulizer and exhibits excellent desalting performance, enabling direct analysis of six drugs dissolved in eight kinds of salt solutions (up to 200 mmol/L) and three complex salty matrices. Under optimized conditions, CSEI-MS presents high sensitivity, accuracy, linearity, and intraday and interday precision. Finally, this method is applied to the quantitative analysis of drugs in seawater, hand cream, and soil. Furthermore, the highly sensitive detection of CSEI-MS is demonstrated to remain even if the detection processes are conducted within 5 s via common commercial tools.


Assuntos
Cristalização , Solventes , Solventes/química , Preparações Farmacêuticas/química , Preparações Farmacêuticas/análise , Água do Mar/química , Água do Mar/análise , Espectrometria de Massas/métodos , Volatilização , Solo/química
10.
Plant Cell Environ ; 47(8): 3227-3240, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38738504

RESUMO

Plants synthesise a vast array of volatile organic compounds (VOCs), which serve as chemical defence and communication agents in their interactions with insect herbivores. Although nitrogen (N) is a critical resource in the production of plant metabolites, its regulatory effects on defensive VOCs remain largely unknown. Here, we investigated the effect of N content in tomato (Solanum lycopersicum) on the tobacco cutworm (Spodoptera litura), a notorious agricultural pest, using biochemical and molecular experiments in combination with insect behavioural and performance analyses. We observed that on tomato leaves with different N contents, S. litura showed distinct feeding preference and growth and developmental performance. Particularly, metabolomics profiling revealed that limited N availability conferred resistance upon tomato plants to S. litura is likely associated with the biosynthesis and emission of the volatile metabolite α-humulene as a repellent. Moreover, exogenous application of α-humulene on tomato leaves elicited a significant repellent response against herbivores. Thus, our findings unravel the key factors involved in N-mediated plant defence against insect herbivores and pave the way for innovation of N management to improve the plant defence responses to facilitate pest control strategies within agroecosystems.


Assuntos
Herbivoria , Nitrogênio , Folhas de Planta , Solanum lycopersicum , Spodoptera , Compostos Orgânicos Voláteis , Solanum lycopersicum/metabolismo , Solanum lycopersicum/fisiologia , Solanum lycopersicum/parasitologia , Animais , Nitrogênio/metabolismo , Spodoptera/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Defesa das Plantas contra Herbivoria , Volatilização , Larva/fisiologia
11.
Environ Sci Technol ; 58(19): 8380-8392, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38691504

RESUMO

A comprehensive understanding of the full volatility spectrum of organic oxidation products from the benzene series precursors is important to quantify the air quality and climate effects of secondary organic aerosol (SOA) and new particle formation (NPF). However, current models fail to capture the full volatility spectrum due to the absence of important reaction pathways. Here, we develop a novel unified model framework, the integrated two-dimensional volatility basis set (I2D-VBS), to simulate the full volatility spectrum of products from benzene series precursors by simultaneously representing first-generational oxidation, multigenerational aging, autoxidation, dimerization, nitrate formation, etc. The model successfully reproduces the volatility and O/C distributions of oxygenated organic molecules (OOMs) as well as the concentrations and the O/C of SOA over wide-ranging experimental conditions. In typical urban environments, autoxidation and multigenerational oxidation are the two main pathways for the formation of OOMs and SOA with similar contributions, but autoxidation contributes more to low-volatility products. NOx can reduce about two-thirds of OOMs and SOA, and most of the extremely low-volatility products compared to clean conditions, by suppressing dimerization and autoxidation. The I2D-VBS facilitates a holistic understanding of full volatility product formation, which helps fill the large gap in the predictions of organic NPF, particle growth, and SOA formation.


Assuntos
Benzeno , Benzeno/química , Compostos Orgânicos/química , Oxirredução , Aerossóis , Volatilização , Poluentes Atmosféricos , Modelos Teóricos
12.
J Chromatogr A ; 1726: 464894, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38733926

RESUMO

Cyclic volatile methylsiloxanes (cVMS) have been widely found in various types of environmental media and attracted increasing attention as new pollutants. However, there is still a great challenge in the accurate quantification of trace cVMS, due to their volatility, and the high background originating from GC/MS accessories and surroundings. In this work, the main sources of the high background were investigated in detail for octamethylcyclotetrasiloxane (D4), decmethylcyclopentasiloxane (D5) and dodecmethylcyclohexosiloxane (D6). Several effective measures were employed to minimize these backgrounds, including the delayed injection method to minimize the interference from the injection septum. Then, a GC-MS method was developed for the accurate determination of D4, D5 and D6, with a linear range of 2 - 200 µg/L. The coefficient of determination was 0.9982-0.9986, the limit of detection (LOD) was 0.40-0.52 µg/L, and the quantitative range was 1.88-190 µg/L. Good reproducibility and recovery were obtained, indicating the reliability of the established analytical method.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Siloxanas , Siloxanas/análise , Siloxanas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Reprodutibilidade dos Testes , Volatilização , Compostos Orgânicos Voláteis/análise
13.
Anal Chem ; 96(18): 7179-7186, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38661266

RESUMO

This study uses real-time monitoring, at microsecond time scales, with a charge-sensing particle detector to investigate the evaporation and fission processes of methanol/micrometer-sized polystyrene beads (PS beads) droplets and bacterial particles droplets generated via electrospray ionization (ESI) under elevated temperatures. By incrementally raising capillary temperatures, the solvent, such as methanol on 0.75 µm PS beads, experiences partial evaporation. Further temperature increase induces fission, and methanol molecules continue to evaporate until PS ions are detected after this range. Similar partial evaporation is observed on 3 µm PS beads. However, the shorter period of the fission temperature range is necessary compared to 0.75 µm PS beads. For the spherical-shaped bacterium, Staphylococcus aureus, the desolvation process shows a similar fission period as compared to 0.75 µm PS beads. Comparably, the rod-shaped bacteria, Escherichia coli EC11303, and E. coli strain W have shorter fission periods than S. aureus. This research provides insights into the evaporation and fission mechanisms of ESI droplets containing different sizes and shapes of micrometer-sized particles, contributing to a better understanding of gaseous macroion formation.


Assuntos
Escherichia coli , Poliestirenos , Espectrometria de Massas por Ionização por Electrospray , Staphylococcus aureus , Poliestirenos/química , Escherichia coli/química , Tamanho da Partícula , Temperatura , Volatilização , Metanol/química , Microesferas
14.
Environ Sci Technol ; 58(18): 7947-7957, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38676647

RESUMO

Volatility of organic aerosols (OAs) significantly influences new particle formation and the occurrence of particulate air pollution. However, the relationship between the volatility of OA and the level of particulate air pollution (i.e., particulate matter concentration) is not well understood. In this study, we compared the chemical composition (identified by an ultrahigh-resolution Orbitrap mass spectrometer) and volatility (estimated based on a predeveloped parametrization method) of OAs in urban PM2.5 (particulate matter with aerodynamic diameter ≤ 2.5 µm) samples from seven German and Chinese cities, where the PM2.5 concentration ranged from a light (14 µg m-3) to heavy (319 µg m-3) pollution level. A large fraction (71-98%) of compounds in PM2.5 samples were attributable to intermediate-volatility organic compounds (IVOCs) and semivolatile organic compounds (SVOCs). The fraction of low-volatility organic compounds (LVOCs) and extremely low-volatility organic compounds (ELVOCs) decreased from clean (28%) to heavily polluted urban regions (2%), while that of IVOCs increased from 34 to 62%. We found that the average peak area-weighted volatility of organic compounds in different cities showed a logarithmic correlation with the average PM2.5 concentration, indicating that the volatility of urban OAs increases with the increase of air pollution level. Our results provide new insights into the relationship between OA volatility and PM pollution levels and deepen the understanding of urban air pollutant evolution.


Assuntos
Aerossóis , Poluentes Atmosféricos , Poluição do Ar , Espectrometria de Massas , Material Particulado , Material Particulado/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Volatilização , Compostos Orgânicos/análise , China , Compostos Orgânicos Voláteis/análise
15.
Bioresour Technol ; 400: 130673, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38583676

RESUMO

The ubiquitous use of volatile siloxanes in a myriad of product formulations has led to a widespread distribution of these persistent contaminants in both natural ecosystems and wastewater treatment plants. Microbial degradation under microaerobic conditions is a promising approach to mitigate D4 and D5 siloxanes while recovering energy in wastewater treatment plants. This study examined D4/D5 siloxanes biodegradation under both anaerobic and microaerobic conditions ( [Formula: see text]  = 0, 1, 3 %) using wastewater sludge. Results show that the use of microaeration in an otherwise strictly anaerobic environment significantly enhances siloxane conversion to methane. 16S rRNA gene sequencing identified potential degraders, including Clostridium lituseburense, Clostridium bifermentans and Synergistales species. Furthermore, chemical analysis suggested a stepwise siloxane conversion preceding methanogenesis under microaerobic conditions. This study demonstrates the feasibility of microaerobic siloxane biodegradation, laying groundwork for scalable removal technologies in wastewater treatment plants, ultimately highlighting the importance of using bio-based approaches in tackling persistent pollutants.


Assuntos
Biodegradação Ambiental , Metano , Siloxanas , Siloxanas/metabolismo , Metano/metabolismo , Esgotos/microbiologia , RNA Ribossômico 16S/genética , Aerobiose , Águas Residuárias/química , Volatilização
16.
Analyst ; 149(11): 3152-3160, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38630503

RESUMO

Cholesterol plays an important biological role in the body, and its disruption in homeostasis and synthesis has been implicated in several diseases. Mapping the locations of cholesterol is crucial for gaining a better understanding of these conditions. Silver deposition has proven to be an effective method for analyzing cholesterol using mass spectrometry imaging (MSI). We optimized and evaluated thermal evaporation as an alternative deposition technique to sputtering for silver deposition in MSI of cholesterol. A silver layer with a thickness of 6 nm provided an optimal combination of cholesterol signal intensity and mass resolution. The deposition of an ultrathin nanofilm of silver enabled high-resolution MSI with a pixel size of 10 µm. We used this optimized method to visualize the distribution of cholesterol in the senile plaques in the brains of APP/PS1 mice, a model that resembles Alzheimer's disease pathology. We found that cholesterol was evenly distributed across the frontal cortex tissue, with no evidence of plaque-like accumulation. Additionally, we investigated the presence and distribution of cholesterol in myocardial sections of a human heart affected by wild-type ATTR amyloidosis. We identified the presence of cholesterol in areas with amyloid deposition, but complete colocalization was not observed.


Assuntos
Colesterol , Prata , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Animais , Colesterol/análise , Colesterol/química , Prata/química , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Camundongos , Camundongos Transgênicos , Placa Amiloide , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagem , Miocárdio/metabolismo , Miocárdio/química , Miocárdio/patologia , Amiloidose/metabolismo , Amiloidose/patologia , Volatilização , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Temperatura
17.
J Sci Food Agric ; 104(11): 6431-6438, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38497421

RESUMO

BACKGROUND: The main aim of the study is to investigate the thermal, textural and vaporization behaviors of turpentine oil (representing essential oils) organogels prepared with wax mixtures (beeswax, BW; shellac wax, SHW) instead of a single wax. The second aim was to determine the optimum level of wax addition to minimize vaporization of volatiles using response surface methodology. RESULTS: Both weighing and thermogravimetric analyses showed that when the total wax concentration increased, the vaporization was decelerated. The variation of the hardness and melting point values depended on both wax types and amounts in the mixtures. Additionally, the kinetics of the vaporization of the volatile compounds at 37 °C were evaluated, and both first- and second-order reaction kinetic models fitted well for the vaporization with R2 values of 0.96-0.99. The organogelation increased the thermal stability and limited the release of volatiles. The multiple response optimization results showed that the melting point, the reaction rate constant and the weight loss of the organogels produced with 24.43% BW and 17.68% SHW were 44.40 °C, 4.00 × 10-3 day-1 and 30.02%, respectively. CONCLUSION: As a result, essential oil organogels produced with a wax mixture instead of a single wax can provide controlled release of volatiles as well as tailored texture and melting range. © 2024 Society of Chemical Industry.


Assuntos
Géis , Óleos Voláteis , Terebintina , Ceras , Ceras/química , Cinética , Géis/química , Óleos Voláteis/química , Terebintina/química , Volatilização , Termogravimetria , Óleos de Plantas/química , Resinas Vegetais
18.
Chemosphere ; 354: 141681, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38467199

RESUMO

Dimethylsilanediol (DMSD) is the common breakdown product of methylsiloxanes such as polydimethylsiloxane (PDMS) and volatile methylsiloxanes (VMS) in soil. In this work, we first present a sorbent selection experiment aiming to identify a sorbent that can trap gas-phase DMSD without causing DMSD condensation and VMS hydrolysis at environmentally relevant humidities. With a proper sorbent (Tenax) identified, the volatilization of DMSD from water and various wet soil and soil materials were measured in a controlled environment. It was demonstrated that DMSD underwent volatilization after soil water was completely evaporated. Various types of soil constituents show drastic differences in preventing DMSD from volatilization. Analysis of the sorbent-captured products provides further insight, most notably that virtually no cyclic methylsiloxanes are formed during the volatilization of DMSD from water or soil materials, except in one extreme case where only traces are detected.


Assuntos
Compostos de Organossilício , Solo , Água , Volatilização
19.
Neurourol Urodyn ; 43(3): 646-654, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38314960

RESUMO

PURPOSE: Benign prostatic obstruction (BPO) is the most common cause of lower urinary tract symptoms among men. GreenLight photoselective vaporization of the prostate (GL-PVP) using a 180-W Xcelerated performance system (XPS) laser is a well-established method for treating BPO-induced voiding symptoms. However, its therapeutic effects on storage symptoms remain unclear. This study aimed to analyze the storage outcomes in patients who underwent 180-W XPS GL-PVP for BPO and to identify outcome predictors. MATERIALS AND METHODS: Patients who underwent 180-W XPS GL-PVP for BPO between May 2018 and May 2021 were retrospectively reviewed. Data on clinical characteristics, prostate volume, preoperative and postoperative International Prostate Symptom Scores (IPSS), and preoperative urodynamic parameters were collected. A favorable storage outcome was defined as ≥50% reduction in the IPSS storage subscore. RESULTS: Ninety-nine male patients were included, with a mean age of 69.4 ± 9.6 years and a baseline prostatic volume of 75.9 ± 33.1 mL. The IPSS total, storage, and voiding subscores significantly decreased after GL-PVP (all p < 0.001). Seventy-two patients achieved favorable storage outcome at 6 months. Multivariate analysis revealed that detrusor underactivity was predictive of unfavorable storage outcomes (p = 0.022), while IPSS voiding-to-storage subscore ratio >1.25 and the presence of detrusor overactivity were predictive of favorable storage outcomes (p = 0.008 and 0.033, respectively). CONCLUSION: 180-W XPS GL-PVP provided excellent outcomes in both voiding and storage lower urinary tract symptoms concomitant with BPO. Preoperative IPSS and multichannel urodynamic parameters including detrusor overactivity and underactivity are valuable predictors of postoperative storage outcomes.


Assuntos
Terapia a Laser , Sintomas do Trato Urinário Inferior , Hiperplasia Prostática , Ressecção Transuretral da Próstata , Obstrução Uretral , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Próstata/cirurgia , Hiperplasia Prostática/complicações , Hiperplasia Prostática/cirurgia , Estudos Retrospectivos , Volatilização , Ressecção Transuretral da Próstata/efeitos adversos , Ressecção Transuretral da Próstata/métodos , Sintomas do Trato Urinário Inferior/cirurgia , Sintomas do Trato Urinário Inferior/complicações , Obstrução Uretral/complicações , Terapia a Laser/efeitos adversos , Terapia a Laser/métodos , Resultado do Tratamento
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 311: 124009, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38335588

RESUMO

Microemulsion is usually a transparent and isotropic liquid mixture composed of oil phase, water phase, surfactant and cosurfactant. The surfactant-framed nanoscale droplets in the microemulsion can penetrate into the skin surface to reduce its barrier function. This makes microemulsion an ideal preparation for the transdermal drug delivery. The permeability of microemulsion may be further enhanced when botanical essential oils that can dissolve the stratum corneum are used as the oil phase. However, the volatility of essential oils is possible to shorten the retention time of the microemulsion on the skin surface. Therefore, analytical methods are required to understand the volatilization process of the microemulsion composed of essential oils to develop the reasonable topical drug carrier system. In this research, Fourier transform infrared (FTIR) spectroscopy with an attenuated total reflection (ATR) accessory cooperated with two-dimensional correlation spectroscopy (2DCOS) to elucidate the volatilization processes of some microemulsions composed of peppermint essential oil. Principal component analysis (PCA) and moving-window two-dimensional correlation spectroscopy (MW2DCOS) revealed the multiple stages of the volatilization processes of the microemulsions. Synchronous 2D correlation infrared spectra indicated the compositional changes during each stage. It was found that the successive volatilizations of ethanol, water and menthone were the major events during the volatilization process of the microemulsion composed of peppermint essential oil. Ethanol can accelerate the volatilization of water, while the composite herbal extract seemed to not influence the volatilization of the other ingredients. After a 20-min-long volatilization process, the remaining microemulsion still contained considerable peppermint essential oil to affect the skin. The above results showed the feasibility of developing the microemulsion composed of peppermint essential oil for the transdermal drug delivery of composite herbal extract. This research also proved that the combination of ATR-FTIR spectroscopy and 2DCOS was valuable to study the volatilization process of the microemulsion.


Assuntos
Óleos Voláteis , Volatilização , Mentha piperita , Tensoativos/química , Água/química , Etanol , Emulsões/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...