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1.
Proc Natl Acad Sci U S A ; 119(15): e2116576119, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35377807

RESUMO

SignificanceWhat makes a molecule have a smell? This simple question represents a significant gap in our understanding of olfaction. To answer it, we trained models to predict whether molecules were odorous based on molecular characteristics and noted which characteristics were needed to make correct predictions. We found that molecules with sufficient volatility and hydrophobicity are generally odorous, which suggests that reaching olfactory receptors is the dominant barrier for prospective olfactory stimuli. Based on these criteria, there are billions of molecules that are likely odorous but have never been smelled. We can now recognize an odorous molecule from its structure, and this guides us to discover new classes of odorants and include all types of odorants in our study of smell.


Assuntos
Odorantes , Olfato , Compostos Orgânicos Voláteis , Animais , Humanos , Aprendizado de Máquina , Modelos Teóricos , Receptores Odorantes , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/classificação , Volatilização
2.
J Environ Radioact ; 248: 106872, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35430501

RESUMO

Radionuclides 129I (t1/2 = 15.7 × 106 years) and 131I (t1/2 = 8.02 days) are both introduced into the environment as a result of nuclear human activities. Environmental transfer pathways and fluxes between and within ecosystems are essential information for risk assessment. In forest ecosystems, humus degradation over time could result in re-mobilization and then downward migration and/or volatilization of intercepted 129I. In order to estimate the scale of these processes, humus (mull and moder forms) sampled under deciduous and coniferous forests were spiked with 125I- (t1/2 = 59.4 days), as a surrogate for 129I, in order to study the evolution of its water-soluble and organic fractions as well as the volatilization rate during humus degradation at laboratory scale. To our knowledge, this is the first time that interactions between iodine and contrasting forms of forest humus have been investigated. The evolution of native stable iodine (127I) pools in unspiked humus was also studied. The nature of the humus' organic matter appears to be a factor that impacts on the proportions of water-soluble and organic fractions of iodine and on their evolution. Iodine-125 was mainly organically bound (fraction for mulls and moders: ∼54-59 and 41-49%, respectively) and no clear evolution was observed within the 4-month incubation period. A large decrease in 125I water-solubility occurred, being more marked for mull (from ∼14-32 to 3-7%) than for moder (from ∼21-37 to 7-19%) humus. By contrast, a significant fraction was not extractible (∼38-43%) and varied in inverse proportion to the water-soluble fraction, suggesting a stabilization of iodine in humus after wet deposit. The nature of the humus organic matter also impacted on 125I volatilization. Although of the same order of magnitude, the total volatilization of 125I was higher for moders (∼0.039-0.323%) than for mulls (∼0.015-0.023%) within the 4-month incubation period. Volatilization rates for mulls were correlated with the water-soluble fraction, implying that volatilization of 125I could occur from the humus solution. Our results showed that humus is thus a zone of iodine accumulation by association with organic matter and that potential losses by lixiviation are significantly more important compared to volatilization.


Assuntos
Iodo , Monitoramento de Radiação , Ecossistema , Florestas , Humanos , Iodetos , Solo , Volatilização , Água
3.
Molecules ; 27(7)2022 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35408720

RESUMO

Ionic liquids (ILs) are recognized as an environmentally friendly alternative to replacing volatile molecular solvents. Knowledge of vaporization thermodynamics is crucial for practical applications. The vaporization thermodynamics of five ionic liquids containing a pyridinium cation and the [NTf2] anion were studied using a quartz crystal microbalance. Vapor pressure-temperature dependences were used to derive the enthalpies of vaporization of these ionic liquids. Vaporization enthalpies of the pyridinium-based ionic liquids available in the literature were collected and uniformly adjusted to the reference temperature T = 298.15 K. The consistent sets of evaluated vaporization enthalpies were used to develop the "centerpiece"-based group-additivity method for predicting enthalpies of vaporization of ionic compounds. The general transferability of the contributions to the enthalpy of vaporization from the molecular liquids to the ionic liquids was established. A small, but not negligible correction term was supposed to reconcile the estimated results with the experiment. The corrected "centerpiece" approach was recommended to predict the vaporization enthalpies of ILs.


Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Temperatura , Termodinâmica , Pressão de Vapor , Volatilização
4.
J Environ Sci (China) ; 114: 259-285, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35459491

RESUMO

Secondary organic aerosol (SOA) is a very important component of fine particulate matter (PM2.5) in the atmosphere. However, the simulations of SOA, which could help to elucidate the detailed mechanism of SOA formation and quantify the roles of various precursors, remains unsatisfactory, as SOA levels are frequently underestimated. It has been found that the performance of SOA formation models can be significantly improved by incorporating the emission and evolution of semivolatile and intermediate-volatility organic compounds (S/IVOCs). In order to explore the roles of S/IVOCs in SOA formation, this study reviews some simulation models which could consider S/IVOCs for SOA formation as well as the development of emission inventories of S/IVOCs and S/IVOC modules for SOA formation. In addition, the future research directions for simulations of the effect of S/IVOCs on SOA formation are suggested.


Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Aerossóis/análise , Poluentes Atmosféricos/análise , Emissões de Veículos/análise , Compostos Orgânicos Voláteis/análise , Volatilização
5.
J Hazard Mater ; 431: 128603, 2022 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-35255333

RESUMO

In the Indian Ocean, the marine fate of polycyclic aromatic hydrocarbons (PAHs) is impacted by the unique air-sea interactions with great monsoon characters. By collecting water-column samples during the monsoon transition period, we found PAHs (∑8PAH: 1.1-27 ng L-1) showed significantly different distributions from the Bay of Bengal, Equatorial Indian Ocean, Eastern Indian Ocean, and the South China Sea (p < 0.001). Their vertical profiles showed natural logarithm relationships with depth in the Bay of Bengal and Equatorial Indian Ocean. PAHs were mainly from wood/coal combustion and vehicle emission. The estimation of PAHs' air-seawater exchange flux revealed net volatilizations from seawater except in the Eastern Indian Ocean. The Wyrtki Jet, a surface current driven by the westerly wind, was observed in the equatorial area. This swift current could transport PAHs eastward efficiently with a mass flux of 636 ± 188 g s-1. The subsurface current, Equatorial Undercurrent, played a less crucial role in PAHs' lateral transport with a flux of 115 ± 31.3 g s-1. This study preliminarily revealed the role of air-sea interactions on PAHs' transport and fate in the open ocean. The coupled air-sea interactions with biogeochemical processes should be considered in future work.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Oceano Índico , Hidrocarbonetos Policíclicos Aromáticos/análise , Água do Mar , Volatilização
6.
Sci Rep ; 12(1): 4418, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35292685

RESUMO

Understanding the diffusive transport behavior of volatile organic compounds (VOCs) in near-surface soils is important because soil VOC emissions affect atmospheric conditions and climate. Previous studies have suggested that temperature changes affect the transport behavior; however, the effect of these changes are poorly understood. Indeed, under dynamic temperature conditions, the change in VOC flux is much larger than that expected from the temperature dependency of the diffusion coefficient of VOCs in air. However, the mechanism is not well understood, although water in soil has been considered to play an important role. Here, we present the results of experiments for the upward vertical vapor-phase diffusive transport of two VOCs (benzene and tetrachloroethylene) in sandy soil under sinusoidal temperature variations of 20-30 °C, as well as its numerical representation. The results clarify that the unexpectedly large changes in emission flux can occur as a result of changes in the VOC concentration gradient due to VOC release (volatilization) from/trapping (dissolution) into water, and that such flux changes may occur in various environments. This study suggests the importance of a global evaluation of soil VOC emissions by continuous measurements in various soil environments and/or predictions through numerical simulations with thorough consideration of the role of water in dynamic soil environments.


Assuntos
Compostos Orgânicos Voláteis , Solo , Temperatura , Volatilização , Água
7.
Huan Jing Ke Xue ; 43(3): 1678-1687, 2022 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-35258232

RESUMO

In order to explore the response of Chinese farmland soil ammonia volatilization to straw returning to the field under different production conditions, this study used no straw returning as a control. Through the collection of published literature test data, the Meta-analysis method was used to quantitatively study the effects of different natural factors and, under the conditions of farmland management measures, the effect of returning straw to the field on the emission reduction of soil ammonia volatilization. At the same time, through partial correlation analysis, the main influencing factors of ammonia volatilization under the condition of returning straw to the field were found, and the ammonia volatilization was quantified. The results showed that the effect of straw returning on soil ammonia volatilization decreased with the increase in accumulated rainfall during the growth period and increased with the increase in average temperature during the growth period. When the soil pH was less than 6, straw returning to the field significantly promoted soil ammonia volatilization, and when the pH was ≥ 6, returning straw to the field significantly inhibited ammonia volatilization in the soil. The reduction effect of returning straw to the field on soil ammonia volatilization increased with the increase in soil clay content. When the total soil nitrogen content was <0.1% and >0.2%, returning the straw to the field significantly inhibited the volatilization of soil ammonia, and when the total soil nitrogen content was between 0.1% and 0.2%, returning the straw to the field significantly promoted the volatilization of ammonia from the soil. When the nitrogen application rate was 60-180 kg·hm-2 and the nitrogen application rate was >240 kg·hm-2, returning straw to the field significantly reduced soil ammonia volatilization (P<0.05), and when nitrogen application rate was 180-240 kg·hm-2, returning straw to the field significantly promoted ammonia volatilization in the soil. Returning straw to the field by plowing or rotary tillage significantly inhibited ammonia volatilization in the soil, whereas returning straw to the field in a mulching mode had no significant effect on ammonia volatilization. When the straw C/N>45, it significantly inhibited ammonia volatilization from the soil, and when the straw C/N ≤ 45, the straw returning to the field significantly promoted the ammonia volatilization of the soil. The reduction effect of straw returning on ammonia volatilization increased with the increase in straw-returning amount. In non-paddy fields, returning straw to the field had a significant inhibitory effect on soil ammonia volatilization, and in paddy fields, returning straw to the field had a significant effect on soil ammonia volatilization. The results of partial correlation analysis showed that in paddy fields, the average growth period and soil pH were the main factors affecting soil ammonia volatilization under the condition of returning straw to the field, and in non-paddy fields, nitrogen application rate and straw C/N were the main factors affecting the conditions. This study can provide reference for the scientific and rational use of straw to achieve ammonia volatilization emission reduction in farmland.


Assuntos
Oryza , Solo , Agricultura/métodos , Amônia/química , Fertilizantes/análise , Nitrogênio/análise , Solo/química , Volatilização
8.
J Insect Sci ; 22(1)2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35137130

RESUMO

The American beekeeping industry continually experiences colony mortality with annual losses as high as 43%. A leading cause of this is the exotic, ectoparasitic mite, Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae). Integrated Pest Management (IPM) options are used to keep mite populations from reaching lethal levels, however, due to resistance and/or the lack of suitable treatment options, novel controls for reducing mites are warranted. Oxalic acid for controlling V. destructor has become a popular treatment regimen among commercial and backyard beekeepers. Applying vaporized oxalic acid inside a honey bee hive is a legal application method in the U.S., and results in the death of exposed mites. However, if mites are in the reproductive stage and therefore under the protective wax capping, oxalic acid is ineffective. One popular method of applying oxalic is vaporizing multiple times over several weeks to try and circumvent the problem of mites hiding in brood cells. By comparing against control colonies, we tested oxalic acid vaporization in colonies treated with seven applications separated by 5 d (35 d total). We tested in apiaries in Georgia and Alabama during 2019 and 2020, totaling 99 colonies. We found that adult honey bees Linnaeus (Hymenoptera: Apidae), and developing brood experienced no adverse impacts from the oxalic vaporization regime. However, we did not find evidence that frequent periodic application of oxalic during brood-rearing periods is capable of bringing V. destructor populations below treatment thresholds.


Assuntos
Abelhas/parasitologia , Ácido Oxálico/farmacologia , Controle de Pragas , Varroidae , Animais , Criação de Abelhas , Varroidae/efeitos dos fármacos , Volatilização
9.
Sci Total Environ ; 825: 153798, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35151737

RESUMO

BACKGROUND: Pesticides can be transported from the site of application to homes via different routes and lead to exposure of residents, raising concerns regarding health effects. We built a deterministic model framework (OBOmod) to assess exposure of residents living near fields where pesticides are applied. METHODS: OBOmod connects five independent models operating on an hourly timescale and high spatial resolution (meters). Models include descriptions of spray drift, volatilization, atmospheric transport and dispersion, exchange between outdoor and indoor air and exchange between indoor air and dust. Fourteen bulb field applications under different weather conditions and comprising 12 pesticides were simulated. Each simulation included the first seven days after the application. The concentrations computed with OBOmod were compared with those measured in outdoor and indoor air and the amounts measured in indoor dust samples. RESULTS: Model evaluation indicated suitability of the developed framework to estimate outdoor and indoor air concentrations. For most pesticides, model accuracy was good. The framework explained about 30% to 95% of the temporal and spatial variability of air concentrations. For 20% of the simulations, the framework explained more than 35% of spatial variability of concentrations in dust. In general, OBOmod estimates remained within one order of magnitude from measured levels. Calculations showed that in addition to spray drift during application, volatilization from the field after spraying and pesticides in house dust are important routes for residents' exposure to pesticides. CONCLUSIONS: Our framework covers many processes needed to calculate exposure of residents to pesticides. The evaluation phase shows that, with the exception of the dust model, the framework can be used in support of health and epidemiological studies, and can serve as a tool to support development of regulations and policy making regarding pesticide use.


Assuntos
Poluição do Ar em Ambientes Fechados , Praguicidas , Poluição do Ar em Ambientes Fechados/análise , Poeira/análise , Exposição Ambiental/análise , Praguicidas/análise , Volatilização
10.
Med Phys ; 49(4): 2761-2773, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35172015

RESUMO

BACKGROUND: Gold nanodroplets (AuNDs) have been proposed as agents for photothermal therapy and photoacoustic imaging. Previously, we demonstrated that the sonoporation can be more effectively achieved with synchronized optical and acoustic droplet vaporization. By applying a laser pulse at the rarefactional phase of the ultrasound (US) pulse, the vaporization threshold can be reached at a considerably lower laser average power. However, a large loading quantity of the AuNDs may increase the risk of air embolism. The destruction of phase-shifted AuNDs at the inertial cavitation stage leads to a reduced drug delivery performance. And it also causes instability of echogenicity during therapeutic monitoring. PURPOSE: In this study, we propose to further improve the sonoporation effectiveness with repeated vaporization. In other words, the AuNDs repeatedly undergo vaporization and recondensation so that sonoporation effects are accumulated over time at lower energy requirements. Previously, repeated vaporization has been demonstrated as an imaging contrast agent. In this study, we aim to adopt this repeated vaporization scheme for sonoporation. METHODS: Perfluoropentane NDs with a shell made of human serum albumin were used as the US contrast agents. Laser pulses at 808 nm and US pulses of 1 MHz were delivered for triggering vaporization and inertial cavitation of NDs. We detected the vaporization and cavitation effects under different activation firings, US peak negative pressures (PNPs), and laser fluences using 5- and 10-MHz focused US receivers. Numbers of calcein-AM and propidium iodide signals uptake by BNL hepatocarcinoma cancer cells were used to evaluate the sonoporation and cell death rate of the cells. RESULTS: We demonstrate that sonoporation can be realized based on repeatable vaporization instead of the commonly adopted inertial cavitation effects. In addition, it is found that the laser fluence and the acoustic pressure can be reduced. As an example, we demonstrate that the acoustic and optical energy for achieving a similar level of sonoporation rate can be as low as 0.44 MPa for the US PNP and 4.01 mJ/cm2 for the laser fluence, which are lower than those with our previous approach (0.53 MPa and 4.95 mJ/cm2 , respectively). CONCLUSION: We demonstrated the feasibility of vaporization-based sonoporation at a lower optical and acoustic energy. It is an advantageous method that can enhance drug delivery efficiency, therapeutic safety and potentially deliver an upgraded gene therapy strategy for improved theragnosis.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Meios de Contraste , Ouro , Humanos , Microbolhas , Volatilização
11.
Chemosphere ; 296: 134052, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35189200

RESUMO

This paper evaluates the combination of electrokinetic soil flushing (EKSF) with soil vapor extraction (SVE) for the removal of four hexachlorocyclohexane (HCH) isomers contained in a real matrix. Results demonstrate that the combination of EKSF and SVE can be positive, but it is required the application of high electric fields (3 V cm-1) in order to promote a higher temperature in the system, which improves the volatilization of the HCH contained in the system. Electrokinetic transport is also enhanced with the application of higher electric gradients, but these transport processes are slower than the volatilization processes, which are the primary in this system. Hence collection of species in the electrolyte wells is negligible as compared to the compound dragged with air by the SVE but the temperature increase demonstrates a good performance. Combination of EKSF with SVE can efficiently exhaust the four HCH isomers reaching a removal of more than 90% after 15 days of treatment (20% more than values attained by SVE) but it is required the application of high electric fields to promote a higher temperature in the system (to improve the volatilization) and EK transport (to improve the dragging). 1-D transport model can be easily used to estimate the average pore water velocity and the effective diffusion of each compound under the different experimental conditions tested.


Assuntos
Poluentes do Solo , Solo , Gases , Hexaclorocicloexano/análise , Poluentes do Solo/análise , Volatilização
12.
Mikrochim Acta ; 189(3): 108, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35171382

RESUMO

Methyl nicotinate (MN) is a representative and typical volatile organic marker of Mycobacterium tuberculosis, and the specific detection of MN in human breath facilitates non-invasive, rapid, and accurate epidemic screening of tuberculosis infection. Herein, we constructed a fluorescent assay consisted of CdTe quantum dots (QD) and cobalt-metalized tetrakis(4-carboxyphenyl) porphyrin (CoTCPP) nanosheets to determine methyl nicotinate (MN) in vapor samples. Red-emission QD (λex=370 nm, λem=658 nm) acts as signal switches whose fluorescence signals can be effectively quenched by CoTCPP nanosheets but restored in the presence of MN. The strategy relied on the distinct binding affinity of cobalt ion and MN. MN restored the fluorescence of QD quenched by CoTCPP in a concentration-dependent manner, which exhibited a well-linear relationship in the range 1-100 µM, and a limit of detection of 0.59 µM. The proposed platform showed sensitivity and selectivity to detect MN in vapor samples with satisfactory RSD below 3.33%. The method is cheap, simple, and relatively rapid (detected within 4 min), which suggests a potential in tuberculosis diagnosis in resource- and professional-lacked areas.


Assuntos
Compostos de Cádmio/química , Mycobacterium tuberculosis/química , Nanopartículas/química , Ácidos Nicotínicos/análise , Porfirinas/química , Pontos Quânticos/química , Telúrio/química , Biomarcadores/análise , Humanos , Espectrometria de Fluorescência , Volatilização
13.
Ultrason Sonochem ; 83: 105948, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35151989

RESUMO

Acoustic droplet vaporization (ADV) is a new approach to generate vapor bubbles that have potentially broad medical applications. ADV-generated bubbles can be used as contrast agents in acoustic imaging, as drug carriers to deliver drugs to particular targets, and also in embolotherapy, thermal therapy, and histotripsy. However, despite much progress, ADV dynamics have still not been well understood and properly modeled. In this paper, we present a theoretical study of ultrasound-induced evaporation of a droplet encapsulated by a shell. The main emphasis of this theoretical study is on a proper description of the supercritical state occurring after bubble collapse. For this purpose, an isentropic equation of state for a van der Waals gas is used to describe the bubble behavior in the supercritical state. Sensitivity of the vaporization process is investigated for different acoustic and geometrical parameters and mechanical properties of the shell. Results show that the value of the minimum pressure required for direct vaporization (without any oscillatory behavior) depends on shell elasticity and initial size of the droplet, especially at high frequencies (greater than 2[MHz]). Moreover, it has been shown that applying an acoustic wave with proper phase such that thermal equilibrium of the bubble temperature with the surrounding liquid is attained, results in direct vaporization at lower acoustic pressure.


Assuntos
Acústica , Gases , Meios de Contraste , Modelos Teóricos , Volatilização
14.
Langmuir ; 38(8): 2634-2641, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35175053

RESUMO

Vaporizable hydrocarbon-in-fluorocarbon endoskeletal droplets are a unique category of phase-change emulsions with interesting physical and thermodynamic features. Here, we show microfluidic fabrication of various morphologies, such as solid-in-liquid, liquid-in-solid, and Janus-type, of complex solid n-C20H42 or n-C21H44 and liquid n-C5F12 droplets. Furthermore, we investigated the vaporization behavior of these endoskeletal droplets, focusing on the effects of heat treatment and core size. Comparison of vaporization and differential scanning calorimetry results indicated that vaporization occurs prior to melting of the bulk hydrocarbon phase for C20H42/C5F10 droplets and near the rotator phase for C21H44/C5F10 droplets. We found that heat treatment of the droplets increased the fraction of droplets that vaporized and also increased the vaporization temperature of the droplets, although the effect was temporary. Furthermore, we found that changing the relative size of the solid hydrocarbon core compared to the surrounding liquid shell increased the vaporization temperature and the vaporizing fraction. Taken together, these data support the hypothesis that surface melting behavior exhibited by the linear alkane may trigger the fluorocarbon vaporization event. These results may aid in the understanding of the interfacial thermodynamics and transport and the engineering of novel vaporizable endoskeletal droplets for biomedical imaging and other applications.


Assuntos
Fluorcarbonetos , Emulsões , Fluorcarbonetos/química , Hidrocarbonetos , Temperatura , Volatilização
15.
Molecules ; 27(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35164204

RESUMO

The volatile flavor profiles and sensory properties of different vegetable soybean varieties popularized and cultivated in China for 20, 10, and 2 years (TW292, X3, and SX6, respectively) were investigated. Nutrient composition analysis revealed that TW292 had a high soluble protein and soluble sugar content but low fat content. The total free amino acid content (15.43 mg/g) and umami free amino acid content (6.08 mg/g) of SX6 were significantly higher (p < 0.05) than those of the other varieties. An electronic tongue effectively differentiated between the umami and sweetness characteristics of the vegetable soybeans. Differences in sensory evaluation results were mainly reflected in texture and taste. A total of 41 volatile compounds were identified through HS-SPME-GC-MS, and the main flavor compounds were 1-octen-3-ol, hexanal, (Z)-2-heptenal, 2-octene, nonanal, (Z)-2-decenal, and 3,5-octadien-2-one. However, the volatile composition of different vegetable soybean varieties exhibited large variability in type and relative contents. Considerable differences in nutritional, organoleptic, and aroma characteristics were found among different varieties. The results of this study will provide a good basis for the assessment and application of the major vegetable soybean varieties grown in China.


Assuntos
Soja/química , Paladar , Verduras/química , Volatilização
16.
Sci Rep ; 12(1): 2638, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35173259

RESUMO

The capture and safe storage of radioactive iodine (129I or 131I) are of a compelling significance in the generation of nuclear energy and waste storage. Because of their physiochemical properties, Porous Organic Polymers (POPs) are considered to be one of the most sought classes of materials for iodine capture and storage. Herein, we report on the preparation and characterization of two triazine-based, nitrogen-rich, porous organic polymers, NRPOP-1 (SABET = 519 m2 g-1) and NRPOP-2 (SABET = 456 m2 g-1), by reacting 1,3,5-triazine-2,4,6-triamine or 1,4-bis-(2,4-diamino-1,3,5-triazine)-benzene with thieno[2,3-b]thiophene-2,5-dicarboxaldehyde, respectively, and their use in the capture of volatile iodine. NRPOP-1 and NRPOP-2 showed a high adsorption capacity of iodine vapor with an uptake of up to 317 wt % at 80 °C and 1 bar and adequate recyclability. The NRPOPs were also capable of removing up to 87% of iodine from 300 mg L-1 iodine-cyclohexane solution. Furthermore, the iodine-loaded polymers, I2@NRPOP-1 and I2@NRPOP-2, displayed good antibacterial activity against Micrococcus luteus (ML), Escherichia coli (EC), and Pseudomonas aeruginosa (PSA). The synergic functionality of these novel polymers makes them promising materials to the environment and public health.


Assuntos
Antibacterianos , Armazenamento de Medicamentos/métodos , Radioisótopos do Iodo , Compostos Orgânicos , Polímeros , Porosidade , Triazinas , Adsorção , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Micrococcus luteus/efeitos dos fármacos , Nitrogênio , Compostos Orgânicos/farmacologia , Polímeros/farmacologia , Triazinas/farmacologia , Volatilização
17.
Zhonghua Yi Xue Za Zhi ; 102(4): 267-272, 2022 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-35073675

RESUMO

Objective: To prospectively compare the efficacy and safety of the greenlight laser anatomical vaporization-incision technique (AVIT) and photoselective vaporization of the prostate(PVP)in the treatment of benign prostatic hyperplasia (BPH). Methods: From November 2019 to September 2020, a randomized controlled study was conducted on 136 BPH patients undergoing greenlight laser surgery in the Department of Urology, the Second Affiliated Hospital of Soochow University. The patient's age ranged from 53 to 85 years and the prostatic volume ranged from 30 to 104 ml. They were divided into two groups by random number table method,including 68 cases of AVIT(observation group)and 68 cases of PVP(control group). The clinical data of the two groups before, during and after operation were collected and analyzed. Results: Operations were successfully completed in the two groups. At 6 months after operation, 63 cases in the observation group and 66 cases in the control group completed the follow-up. There was no significant difference in the prevalence of hypertension, diabetes, coronary heart disease, atrial fibrillation and renal insufficiency between the two groups before operation (all P>0.05). The differences of preoperative age [(66.8±6.5) vs (67.3±5.4) years], international prostate symptom score (IPSS) [(24.2±4.7) vs (23.5±4.5) ], quality of life score (QOL) [4.7(4.1, 4.9) vs 4.6(4.2, 5.0)], peak urinary flow rate (Qmax) [(6.9±2.8) vs (6. 8±2.6) ml/s], post-void residual volume (PVR) [(137(52.8, 190.9) vs 119(70.6, 172.1) ml], prostate volume (PV) [70.5(60.6, 80.9) vs 68.2(61.2, 80.5) ml], serum prostate specific antigen (PSA) [4.4(3.5, 5.1) vs 4.4(3.4, 5.0) ng/ml] were not statistically significant between the two groups (all P>0.05). There was no significant difference in the amount of intraoperative blood loss, catheterization time and the postoperative hospitalization time between the two groups (all P>0.05). Compared with the control group, the operation time and lasing time of the observation group were longer[69.0(64.6, 75.0) vs 55.8(49.1, 63.4) min,(36.3±9.9) vs (31.3±9.3) min], and the intraoperaive laser energy consumption and laser energy density were higher[(297±20) vs (240±20) kJ,(4.50±1.35) vs (3.73±1.17) kJ/ml]. The differences were all statistically significant (all P<0.05). At the follow-up of 1, 3 and 6 months after operation, IPSS and QOL in the observation group were lower than those in the control group, and the differences were all statistically significant (all P<0.05). Qmax in the observation group was higher and PVR was lower than those in the control group, with statistically significant differences (P<0.05). Six months after operation, PV and PSA in the observation group decreased more significantly than those in the control group (56% vs 47%, 70% vs 60%, both P<0.05). No urethral stricture and urinary incontinence occurred in two groups after operation. The incidence rate of urinary tract irritation in the observation group was 6.3%(4/63),lower than the 18.2%(12/66)in the control group (P<0.05). There was no significant difference in the incidence rates of urinary retention, bladder neck contracture and secondary bleeding between the two groups (all P>0.05). Conclusions: Greenlight laser anatomical vaporization-incision technique is safe and effective in the treatment of BPH. Compared with PVP, AVIT has more prostate tissue removed and better curative effect, which is worthy of clinical promotion.


Assuntos
Terapia a Laser , Hiperplasia Prostática , Ressecção Transuretral da Próstata , Idoso , Idoso de 80 Anos ou mais , Humanos , Lasers , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Próstata/cirurgia , Hiperplasia Prostática/cirurgia , Qualidade de Vida , Resultado do Tratamento , Volatilização
18.
J Hazard Mater ; 428: 128214, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35042164

RESUMO

Boron carbide control rods remain in the fuel debris of the damaged reactors in the Fukushima Daiichi Nuclear Power Plant, potentially preventing re-criticality; however, the state and stability of the control rods remain unknown. Sensitive high-resolution ion microprobe analyses have revealed B-Li isotopic signatures in radioactive Cs-rich microparticles (CsMPs) that formed by volatilization and condensation of Si-oxides during the meltdowns. The CsMPs contain 1518-6733 mg kg-1 of 10+11B and 11.99-1213 mg kg-1 of 7Li. The 11B/10B (4.15-4.21) and 7Li/6Li (213-406) isotopic ratios are greater than natural abundances (~4.05 and ~12.5, respectively), indicating that 10B(n,α)7Li reactions occurred in B4C prior to the meltdowns. The total amount of B released with CsMPs was estimated to be 0.024-62 g, suggesting that essentially all B remains in reactor Units 2 and/or 3 and is enough to prevent re-criticality; however, the heterogeneous distribution of B needs to be considered during decommissioning.


Assuntos
Acidente Nuclear de Fukushima , Monitoramento de Radiação , Césio , Radioisótopos de Césio , Japão , Centrais Nucleares , Volatilização
19.
PLoS One ; 17(1): e0262265, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35081135

RESUMO

Vaporized cannabis is believed to be safer than smoking, but when heated to excessive temperatures nearing combustion (>900 °C) harmful byproducts may form. While some cannabis extract vaporizers operate well below these high temperatures, heating coil temperatures obtained during actual use are frequently not reported and many operate at high temperatures. We report on two major objectives: 1) development of an infrared thermography method to measure heating coil temperatures in cannabis extract vaporizers during a simulated puff and 2) a comparison of temperature- to voltage- controlled cannabis extract vaporization systems during a puff. Infrared thermography was used to measure heating coil temperatures in one temperature-controlled and two voltage-controlled systems. The cartridges were modified for direct line-of-sight on the heating coils, the wick and coils were saturated with cannabis extract, and fixtures were developed to force two liters per minute air flow past the coils for the full duration of the puff allowed by the device. The voltage-controlled systems produced higher temperatures with greater variability than the temperature-controlled system. At the highest temperature setting (420 °C) the temperature-controlled system reached an average heating coil temperature of 420 ± 9.5 °C whereas the 4.0V setting on the variable voltage system reached an average temperature of 543 ± 95.9 °C and the single voltage (3.2V) system an average of 450 ± 60.8 °C. The average temperature at the lowest setting (270 °C) on the temperature-controlled system was 246 ± 5.1 °C and the variable voltage system (2.4V) was 443 ± 56.1 °C. Voltage alone was a poor indicator of coil temperature and only the temperature-controlled system consistently maintained temperatures less than 400 °C for the full puff duration. These lower temperatures could reduce the likelihood of harmful thermal degradation products and thus may reduce potential health risk to consumers when vaporizing cannabis extracts.


Assuntos
Fumar Maconha , Vaping , Cannabis , Humanos , Temperatura , Termografia , Volatilização
20.
Sci Total Environ ; 820: 153158, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35063523

RESUMO

Pesticide use in current cropping systems has become a key input to improve productivity. However, their potential risk to nature demands tools for designing a sustainable use. In this work, a fuzzy knowledge-based model was developed for assessing risk of pesticides into the air. The model was based on fuzzy logic theory which provides a means for representing uncertainty by including knowledge about different processes related to pesticide dynamics using functions, control rules and logical inference systems. All these elements were built through a literature review. Results from the sensitivity analysis on the final model structure showed that the Henry's law constant was the most influential input variable related to the active ingredient identity, while the most influential management and environmental input variables on the pesticide air risk values were the droplet size together with the application method and the current wet bulb temperature depression value, respectively. Results from an independent model validation showed a significant goodness-of-fit between the simulated risk of drift and volatilization and the observed values under experimental conditions. Long-term simulations in a real soybean production system in Argentina showed results of drift reduction in post-emergence conditions of the crop under aerial application condition, and a significant effect of the identity of the active ingredient in the risk values. Simulated risk values from the developed model allow to identify ex ante the combination of agronomic decisions, together with environmental conditions that can reduce the risk of pesticides in the air in real production systems. Further combination with ecotoxicological classification tools should improve pesticide use assessment in agricultural systems.


Assuntos
Praguicidas , Agricultura/métodos , Ecotoxicologia , Lógica Fuzzy , Praguicidas/análise , Volatilização
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