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1.
J Proteome Res ; 18(7): 2979-2986, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31173681

RESUMO

An effective three-step proteomics workflow is proposed to overcome the pitfalls caused by polymers present in optimum cutting temperature (OCT)-embedded tissue during its preparation for mass spectrometry analysis. First, the OCT-embedded tissue biopsies are cleaned using ethanol and water in a sequential series of ultrasonic washes in an ultrasound bath (35 kHz ultrasonic frequency, 100% ultrasonic amplitude, 2 min of ultrasonic duty time). Second, a fast ultrasonic-assisted extraction of proteins is done using an ultrasonic probe (30 kHz ultrasonic frequency, 50% ultrasonic amplitude, 2 min of ultrasonic duty time, 1 mm diameter tip). Third, a rapid ultrasonic digestion of complex proteomes is performed using a microplate horn assembly device (20 kHz ultrasonic frequency, 25% ultrasonic amplitude, 4 min of ultrasonic duty time). As a proof of concept, the new workflow was applied to human normal and tumor kidney biopsies including chromophobe renal cell carcinomas (chRCCs) and renal oncocytomas (ROs). A successful cluster of proteomics profiles was obtained comprising 511 and 172 unique proteins found in chRCC and RO samples, respectively. The new method provides high sample throughput and comprehensive protein recovery from OCT samples.


Assuntos
Neoplasias/química , Proteoma/análise , Manejo de Espécimes/métodos , Inclusão do Tecido/métodos , Adenoma Oxífilo/química , Biópsia , Carcinoma de Células Renais/química , Humanos , Neoplasias Renais/química , Neoplasias/patologia , Estudo de Prova de Conceito , Espectrometria de Massas em Tandem , Ultrassom
2.
Int Ophthalmol ; 39(8): 1761-1766, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30054849

RESUMO

PURPOSE: To compare the amount of phacoemulsification ultrasound energy used between eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification. METHODS: One eye of consecutive patients undergoing routine non-complicated phacoemulsification from January 2014 to December of 2015 was included in the analysis. FLACS was performed using the Alcon LenSx. Linear regression was used for analysis with type of surgery (FLACS versus conventional phacoemulsification) as the exposure and cumulative dispersed energy (CDE) as the outcome variable. Age, surgeon, eye side, and eye sequence (first versus second eye) were covariates. RESULTS: A total of 1159 surgeries met inclusion criteria. The average age of the cohort was 70.6 (SD 8.6) years, 590 cases (51%) were performed by surgeon 1, and 582 cases (50%) were right eyes. Overall, FLACS resulted in significantly lower CDE as compared to conventional phacoemulsification (ß = 0.89, 95% CI 0.83, 0.95). When stratified by eye side and surgeon, FLACS performed on left eyes operated on by surgeon 1 resulted in lower CDE as compared to conventional phacoemulsification (ß = 0.76, 95% CI 0.66, 0.87), but not for right eyes operated on by surgeon 1 (ß = 0.92, 95% CI 0.79, 1.07) or for eyes operated on by surgeons 2 or 3. CONCLUSIONS: The use of FLACS on the Alcon LenSx platform results in a small decrease in phacoemulsification energy as compared to conventional phacoemulsification in certain cases. Further study assessing optimal laser settings and surgical technique is necessary.


Assuntos
Terapia a Laser/métodos , Facoemulsificação/métodos , Acuidade Visual , Idoso , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Resultado do Tratamento , Ondas Ultrassônicas
3.
Sensors (Basel) ; 17(12)2017 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-29207530

RESUMO

During the propagation of ultrasonic waves in structures, there is usually energy loss due to ultrasound energy diffusion and dissipation. The aim of this research is to characterize the ultrasound energy diffusion that occurs due to small-size damage on an aluminum plate using piezoceramic transducers, for the future purpose of developing a damage detection algorithm. The ultrasonic energy diffusion coefficient is related to the damage distributed in the medium. Meanwhile, the ultrasonic energy dissipation coefficient is related to the inhomogeneity of the medium. Both are usually employed to describe the characteristics of ultrasound energy diffusion. The existence of multimodes of Lamb waves in metallic plate structures results in the asynchronous energy transport of different modes. The mode of Lamb waves has a great influence on ultrasound energy diffusion as a result, and thus has to be chosen appropriately. In order to study the characteristics of ultrasound energy diffusion in metallic plate structures, an experimental setup of an aluminum plate with a through-hole, whose diameter varies from 0.6 mm to 1.2 mm, is used as the test specimen with the help of piezoceramic transducers. The experimental results of two categories of damages at different locations reveal that the existence of damage changes the energy transport between the actuator and the sensor. Also, when there is only one dominate mode of Lamb wave excited in the structure, the ultrasound energy diffusion coefficient decreases approximately linearly with the diameter of the simulated damage. Meanwhile, the ultrasonic energy dissipation coefficient increases approximately linearly with the diameter of the simulated damage. However, when two or more modes of Lamb waves are excited, due to the existence of different group velocities between the different modes, the energy transport of the different modes is asynchronous, and the ultrasonic energy diffusion is not strictly linear with the size of the damage. Therefore, it is recommended that only one dominant mode of Lamb wave should be excited during the characterization process, in order to ensure that the linear relationship between the damage size and the characteristic parameters is maintained. In addition, the findings from this paper demonstrate the potential of developing future damage detection algorithms using the linear relationships between damage size and the ultrasound energy diffusion coefficient or ultrasonic energy dissipation coefficient when a single dominant mode is excited.

4.
Adv Mater ; 36(2): e2307194, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37884338

RESUMO

In implantable bioelectronics, which aim for semipermanent use of devices, biosafe energy sources and packaging materials to protect devices are essential elements. However, research so far has been conducted in a direction where they cannot coexist. Here, the development of capacitance-matched triboelectric implants driven is reported by ultrasound under 500 mW cm-2 safe intensity and realize a battery-free, miniatured, and wireless neurostimulator with full titanium (Ti) packaging. The triboelectric implant with high dielectric composite, which has ultralow output impedance, can efficiently deliver sufficient power to generate the stimulation pulse without an energy-storing battery, despite ultrasound attenuation due to the Ti, and has the highest energy transmission efficiency among those reported so far. In vivo study using a rat model demonstrated that the proposed device system is an effective solution for relieving urinary symptoms. These achievements provide a significant step toward permanently implantable devices for controlling human organs and treating various diseases.


Assuntos
Fontes de Energia Elétrica , Próteses e Implantes , Humanos , Ratos , Animais , Ultrassonografia , Capacitância Elétrica
5.
ArXiv ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38979489

RESUMO

Real-time monitoring of dynamic biological processes in the body is critical to understanding disease progression and treatment response. This data, for instance, can help address the lower than 50% response rates to cancer immunotherapy. However, current clinical imaging modalities lack the molecular contrast, resolution, and chronic usability for rapid and accurate response assessments. Here, we present a fully wireless image sensor featuring a 2.5×5 mm2 CMOS integrated circuit for multicolor fluorescence imaging deep in tissue. The sensor operates wirelessly via ultrasound (US) at 5 cm depth in oil, harvesting energy with 221 mW/cm2 incident US power density (31% of FDA limits) and backscattering data at 13 kbps with a bit error rate <10-6. In-situ fluorescence excitation is provided by micro-laser diodes controlled with a programmable on-chip driver. An optical frontend combining a multi-bandpass interference filter and a fiber optic plate provides >6 OD excitation blocking and enables three-color imaging for detecting multiple cell types. A 36×40-pixel array captures images with <125 µm resolution. We demonstrate wireless, dual-color fluorescence imaging of both effector and suppressor immune cells in ex vivo mouse tumor samples with and without immunotherapy. These results show promise for providing rapid insight into therapeutic response and resistance, guiding personalized medicine.

6.
ACS Appl Mater Interfaces ; 16(37): 49069-49082, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39236665

RESUMO

Transdermal drug delivery systems are highly appealing as a convenient drug delivery manner applicable to a wide variety of drugs. While most delivery relies on only passive diffusion and suffers low transdermal efficiencies. Ultrasound motivation promotes drug transdermal penetration but still calls for improvement, because only a thin proportion of the ultrasound energy is applied on the drug delivery patch and most ultrasound energy is wasted in deeper portions of biotissues. In this work, we develop a transdermal patch for enhanced drug delivery. The combination of microsized air pockets and the piezoelectric soft structure enable the conversion of an intended proportion of ultrasound energy into electric energy. The intensified drug flow and synergistic ultrasound pressure and electric field function simultaneously to enhance drug transdermal delivery. The delivery efficacy is related to the power of the ultrasound motivation, the size of the microscopic air pockets, and the chemical structure of the drug molecules. The temperature of the patch within the delivery process remains in the safe range, and the mild temperature elevation causes color changes of the thermochromic patch, used to indicate effective ultrasound-patch matching. A model delivery patch for pain release is constructed, and animal experiments indicate that the drug blood concentrations are 100% higher than the delivery using only ultrasound and even more remarkably enhanced when compared to only electric-field-motivated delivery or static delivery without external motivations.


Assuntos
Administração Cutânea , Sistemas de Liberação de Medicamentos , Microbolhas , Animais , Adesivo Transdérmico , Pele/metabolismo , Camundongos , Ondas Ultrassônicas
7.
J Plast Reconstr Aesthet Surg ; 94: 20-26, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38733713

RESUMO

BACKGROUND: Ultrasound-assisted liposuction (UAL) has become popular because of its favorable outcomes in fat emulsification, blood loss reduction, and skin tightening. This study aimed to compare the effects of two UAL devices on the abdomen by assessing postsurgery skin biomechanical properties. METHODS: This single-blind, prospective study (2020-2022) involved 13 liposuction procedures performed on patients without chronic diseases. Each patient's abdomen was divided vertically from the xiphoid to the perineum. Vibration amplification of sound energy at resonance (VASER)-assisted liposuction (Solta Medical, Inc., Hayward, CA) was performed on one half, while the other half underwent liposuction with high-frequency ultrasound energy (HEUS)-assisted technology. Skin biomechanical measurements, including distensibility, net elasticity, biological elasticity, hydration, erythema, melanin, and skin firmness, were taken at 12 and 24 months postsurgery, focusing on the anterior abdomen, 8 cm to the right and left of the umbilicus. RESULTS: Analysis of the above skin biomechanical measurements revealed no significant differences between the HEUS and VASER devices, except for skin firmness, which showed a notable increase following HEUS surgery. Patient-perceived clinical differences were assessed via nonvalidated questionnaires, revealing no distinctions between devices. CONCLUSION: Biomechanical skin results post-UAL surgery with these devices on the abdomen were not significantly different, although HEUS revealed increased skin firmness. This suggests that HEUS-assisted technology, akin to other devices, is a viable option for UAL procedures.


Assuntos
Lipectomia , Humanos , Lipectomia/métodos , Lipectomia/instrumentação , Feminino , Estudos Prospectivos , Adulto , Método Simples-Cego , Pessoa de Meia-Idade , Masculino , Abdome/cirurgia , Terapia por Ultrassom/métodos , Fenômenos Fisiológicos da Pele
8.
Acta Ophthalmol ; 100(2): e414-e422, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34543523

RESUMO

PURPOSE: The purpose of the study was to compare ultrasound (US) consumption and central macular thickness (CMT) and volume changes with manual and femtosecond laser (FSL)-assisted cataract nucleus workup. METHODS: Sixty patients scheduled for immediate sequential bilateral surgery underwent a prospective randomized intraindividual comparison of nucleus sector fragmentation performed manually in one eye and with low-energy FSL assistance in the partner eye, followed by high-fluidics phacoaspiration with a maximum US power of 30%. Ultrasound (US) energy consumption and macular thickness and volume were compared as measured by intraoperative effective phacoemulsification time (EPT) and high-resolution spectral domain optical coherence tomography pre- and 1 week, 3 weeks and 6 weeks postoperatively. Results are presented as means ± SD or medians [min; max]. RESULTS: Fifty-two patients completed the full follow-up. For the manual and FSL-assisted groups, nuclear hardness was almost identical with a mean LOCS III grade of 2.44 ± 1.08 and 2.50 ± 1.00 (p = 0.371). Median EPT was 1.40 [0.2; 8.3] and 1.25 [0.2; 9.4] seconds. Median preoperative CMT was 276.50 [263.25; 289.75] µm and 276.00 [262.00; 290.00] µm. Median postoperative CMT was 278.00 [260.50; 288.00] versus 275.50 [264.00; 290.50] µm at 1 week, 279.50 [266.75; 292.25] versus 280.00 [266.50; 294.50] µm at 3 weeks and 280.50 [268.00, 293.75] versus 279.50 [264.75; 295.25] µm at 6 weeks. Differences in CMT and total macular volume between the groups were not statistically significant at any point in time. CONCLUSION: Femtosecond laser (FSL) prefragmentation of the nucleus into six sectors did not reduce US energy consumption compared with manual splitting of the nucleus into four quadrants in this particular surgical setting. Sectorial FSL-prechopping with the low-energy FSL used had no additional impact on postoperative macular thickness and volume.


Assuntos
Terapia a Laser/métodos , Macula Lutea/patologia , Facoemulsificação/métodos , Idoso , Método Duplo-Cego , Feminino , Humanos , Macula Lutea/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tomografia de Coerência Óptica , Ultrassonografia
9.
Ultrason Sonochem ; 72: 105453, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33412386

RESUMO

Nitrocellulose is a nitrated cellulose polymer with a broad application in industry. Depending on the nitrogen content, this polymer can be used for manufacturing explosives, varnishes, clothes, and films, being considered a product of high value-added. In this work, the use of ultrasound was investigated for the intensification of nitrocellulose synthesis from microcrystalline cellulose. The ultrasound-assisted nitrocellulose synthesis (UANS) was carried out using several ultrasound systems, such as baths and cup horns, allowing the evaluation of the frequency (from 20 to 130 kHz) and delivered power (from 23 to 134 W dm-3) to the reaction medium. The following parameters were evaluated: acid mixture (H2SO4, H3PO4, CH2O2 or CH3COOH with HNO3, 2 to 14.4 mol L-1), ultrasound amplitude (10 to 70%) and reaction time (5 to 50 min). Better nitrocellulose yield (nitrogen content of 12.5% was obtained from 1 g of microcrystalline cellulose employing a cup horn system operating at 20 kHz, 750 W of nominal power with 60% of amplitude, 25 mL of acid solution (13.6 mL of 18.4 mol L-1 H2SO4 + 9.2 mL of 14.4 mol L-1 HNO3 + 2.2 mL H2O), at 30 °C for 30 min. At silent conditions (mechanical stirring ranging from 100 to 500 rpm), the nitrogen content was lower than 11.8% which demonstrate the ultrasound effects for nitrocellulose synthesis.

10.
Food Chem ; 334: 127559, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711270

RESUMO

This study approaches the development of a method for the determination of Ca, Mg, Zn, and Fe in liquid and powdered cow milk. The method is based on sample dissolution assisted by ultrasound energy in tetramethylammonium hydroxide (TMAH) media and determination by flame atomic absorption spectrometry (FAAS). Central composite design (CCD) associated with response surface methodology and desirability function allowed the fast and efficient optimization of the variables involved in the performance of the dissolution. The developed dissolution method allowed Ca, Fe, Zn, and Mg determination in milk samples with adequate analytical characteristics for these determinations. Addition/recovery tests and analysis of a certified reference material of skimmed powdered milk (ERM-BD150) have shown that this method presents enough accuracy to carry out these analyses.


Assuntos
Análise de Alimentos/métodos , Metais/análise , Leite/química , Compostos de Amônio Quaternário/química , Espectrofotometria Atômica/métodos , Animais , Bovinos , Feminino , Análise de Alimentos/estatística & dados numéricos , Análise Multivariada , Pós , Solubilidade
11.
Indian J Ophthalmol ; 68(10): 2103-2106, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32971617

RESUMO

PURPOSE: The purpose of this study is to evaluate fluid droplet spray generation during phacoemulsification (PE), pars plana vitrectomy (PPV), and fragmatome lensectomy (FL) and assess factors affecting these. METHODS: This is an experimental study. PE through 2.2 and 2.8 mm incisions was performed in six goat eyes and four simulator eyes using both continuous and interrupted ultrasound (U/S). PPV and FL were performed in three goat eyes. Generation of visible fluid droplet spray was analyzed from video recordings through the microscope camera and an external digital camera. Hydroxypropylmethylcellulose (HPMC) was applied over the incision site during PE and FL. RESULTS: When PE was performed through both incision sizes, there was no visible fluid droplet spray if the phaco tip was centered in the incision, without sleeve compression. When there was phaco tip movement with the phaco sleeve sandwiched between the tip and the incision wall, there was visible fluid droplet spray generation. It was more difficult to induce fluid droplet spray with 2.8 mm incision, and spray was lesser with interrupted U/S. During PPV, there was no droplet spray. During FL, fluid droplet spray was only seen when U/S was delivered with the fragmatome tip close to the sclerotomy. HPMC impeded droplet spray. CONCLUSION: Fluid droplet generation during PE can be minimized to a large extent by keeping the phaco tip centered within the incision, avoiding sleeve compression. Smaller incision and continuous U/S were more prone to droplet generation. FL should be performed away from sclerotomy. HPMC over incision is recommended.


Assuntos
Betacoronavirus , Líquidos Corporais/química , Infecções por Coronavirus/epidemiologia , Complicações Intraoperatórias , Microbolhas , Facoemulsificação/instrumentação , Pneumonia Viral/epidemiologia , Vitrectomia/instrumentação , Experimentação Animal , Animais , COVID-19 , Infecções por Coronavirus/prevenção & controle , Cabras , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Pandemias/prevenção & controle , Fotografação , Pneumonia Viral/prevenção & controle , SARS-CoV-2 , Gravação em Vídeo
12.
ACS Nano ; 14(3): 3199-3207, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32078295

RESUMO

Ultrasound is a source of ambient energy that is rarely exploited. In this work, a tissue-mimicking MXene-hydrogel (M-gel) implantable generator has been designed to convert ultrasound power into electric energy. Unlike the present harvesting methods for implantable ultrasound energy harvesters, our M-gel generator is based on an electroacoustic phenomenon known as the streaming vibration potential. Moreover, the output power of the M-gel generator can be improved by coupling with triboelectrification. We demonstrate the potential of this generator for powering implantable devices through quick charging of electric gadgets, buried beneath a centimeter thick piece of beef. The performance is attractive, especially given the extremely simple structure of the generator, consisting of nothing more than encapsulated M-gel. The generator can harvest energy from various ultrasound sources, from ultrasound tips in the lab to the probes used in hospitals and households for imaging and physiotherapy.


Assuntos
Carbono/química , Hidrogéis/química , Nanoestruturas/química , Compostos de Nitrogênio/química , Titânio/química , Ondas Ultrassônicas , Fontes de Energia Bioelétrica , Eletricidade , Desenho de Equipamento
13.
Food Addit Contam Part B Surveill ; 13(4): 268-274, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32449491

RESUMO

Casein and ovalbumin are proteins commonly used as wine fining agents that may trigger allergic reactions in susceptible individuals. Therefore, their occurrence in wines could become a health risk, moreover when their presence is not reported. The objective of this work was to determine the occurrence of casein and ovalbumin in Chilean wines. Proteins were extracted by ultrafiltration and digested applying an optimised ultrasound-assisted method. Peptides were quantified by validated tandem mass spectrometry method using stable isotope dilution analysis. Optimal digestion was achieved in 3 minutes at a 1:10 enzyme protein ratio. The method was validated following ICH guidelines showing determination coefficients R2 ≥ 0.99, repeatability, and intermediate precision with RSD values <1.95% and recoveries from 89.8% to 115.1% (RSD < 5.84%). The method was applied to analyse 60 wine samples. Fifty-six samples showed quantifiable levels, from which 28% presented a total casein and ovalbumin concentration equal or higher to the European limit (0.25 mg L-1).


Assuntos
Alérgenos/análise , Caseínas/análise , Ovalbumina/análise , Vinho/análise , Caseínas/imunologia , Chile , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Humanos , Concentração Máxima Permitida , Ovalbumina/imunologia , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos , Tripsina/metabolismo
14.
Ultrason Sonochem ; 67: 105148, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32388313

RESUMO

The aim of this paper was to evaluate the effect of high energy ultrasound on the bioaccessibility of bioactive compounds from açaí (Euterpe precatoria) and buriti (Mauritia flexuosa) juices. Five levels of energy density (0, 0.9, 1.8, 2.7 and 3.6 J.cm-3), as well as their effects on the bioactive compounds were evaluated. Ultrasound did not significantly influence pH, titratable acidity and soluble solids. However, it affected the color attributes of juices by increasing brightness and color variation. The concentration of bioactive compounds (anthocyanins and carotenoids) and antioxidants increased with increasing ultrasound energy density, which was confirmed by Principal Component Analysis (PCA). Fatty acids increased up to 2.7 J.cm-3 and were reduced when higher energy was employed on the ultrasound process. Ultrasound allowed the release of new aromatic substances. For this reason, the ultrasound technology can be considered an alternative pre-treatment for fruit juices, improving the bioaccessibility and concentration of bioactive compounds.


Assuntos
Frutas/metabolismo , Sonicação , Antocianinas/metabolismo , Disponibilidade Biológica , América do Sul , beta Caroteno/metabolismo
15.
Acta Ophthalmol ; 98(2): e155-e160, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31469490

RESUMO

PURPOSE: The purpose of this study was to establish a standardized in vitro phacoemulsification damage model for future investigations of the effects of phacoemulsification, surgical devices, protective ophthalmic viscoelastic devices (OVDs), irrigation solutions and other aspects related to cataract phacoemulsification surgery on the corneal endothelium using porcine eyes. METHODS: Thirty-four porcine eyes were randomly assigned to three groups (phacoemulsification (n = 13), irrigation (n = 9), control (n = 12)). A total of 5 min of ultrasound energy with intermittent irrigation/aspiration was applied in the eyes of the phacoemulsification group. The eyes of the irrigation group received the identical treatment, but without the application of ultrasound energy. The control group was left untreated. All eyes were then prepared to split corneal buttons followed by 15 days of cultivation. Endothelial cell density (ECD) was assessed blinded on day 15. RESULTS: Endothelial cell density declined significantly more until day 15 in the phacoemulsification group (2567 ± 317/267 cells/mm² (median ± 25%/75%-quartiles), -32.5 ± 7.0/6.4%) compared to the irrigation (3450 ± 350/383 cells/mm², -11.8 ± 5.3/2.6%; p < 0.001) and the control group (3650 ± 288/258 cells/mm², -10.2 ± 3.2/4.6%; p < 0.001). CONCLUSION: The phacoemulsification damage model presented in this study is sensitive to phacoemulsification energy and may reliably be used to investigate various factors involved in phacoemulsification with regard to their influence on corneal endothelial cells. This method is able to replace animal experiments or in vitro cell culture experiments that often do not translate well to the in vivo situation in humans.


Assuntos
Perda de Células Endoteliais da Córnea/etiologia , Modelos Animais de Doenças , Endotélio Corneano/patologia , Facoemulsificação/efeitos adversos , Procedimentos Cirúrgicos Ultrassônicos/efeitos adversos , Animais , Contagem de Células , Perda de Células Endoteliais da Córnea/patologia , Técnicas de Cultura de Órgãos , Suínos , Irrigação Terapêutica , Substâncias Viscoelásticas
16.
Ultrason Sonochem ; 51: 40-48, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30514484

RESUMO

An innovative ultrasonic assisted microextraction method using a deep eutectic solvent for entrapping the organ metallic complexes was developed to pre-concentrate the trace quantities of cadmium (Cd) and lead (Pb) in lipsticks and eye shadows of different brands prior to flame atomic absorption spectrometry analysis. A deep eutectic solvent (DES) was used in this study, prepared by mixing metal salt (ZnCl2) and hydrogen bond donors such as (acetamide) in different ratio. The different branded cosmetic items, lipstick and eye shadows, obtained from local market and subjected to acid digestion prior to application of proposed ultrasonic assisted microextraction method based on deep eutectic solvent (UAµE-DES) with the aid of mechanical and ultrasound energies. Ammonium pyrrolidine dithiocarbamate was used as a ligand to made hydrophobic complexes of Cd and Pb, entrapped in DES in the presence of aprotic solvent. The seven variables, mixing ratio of ZnCl2 and Acetamide, DES volume, Ultrasound and Conventional shaking time, pH, tetrahydrofuran and complexing reagent volume were optimized by multivariate approach for the optimum recovery of Cd and Pb from real cosmetic items. The resulted data indicates that ultrasound energy assisted extraction time, volume of DES and pH were most significant variables. The precision and validity of developed procedure were checked by the spiked known certified standards in real samples. The resulted data indicated that the lipsticks have different glittering colors contains high contents of Pb and Cd, whereas dark colors of eye shadows contain high level of both elements.

17.
Biotechnol Prog ; 35(3): e2802, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30843373

RESUMO

A procedure for the alkaline pretreatment of sisal fiber assisted by ultrasound was optimized to obtain a higher solubilization of hemicellulose and the removal of lignin with cellulose fraction maintenance. A full factorial design 23 was used for the evaluation of the effects of the variables (sonication time, NaOH concentration, and sonication amplitude) on the pretreatment. The optimal values for the variables using the Doehlert matrix for the sonication time, NaOH concentration, and sonication amplitude were 27 min, 4.1% (m/v), and 50%, respectively. The X-ray diffractometry and scanning electron microscopy analyses, after pretreatment, showed changes in chemical structure and morphology due to the removal of 82% of hemicellulose and 86% of lignin from sisal fiber. The soft reaction conditions and relatively short times demonstrated the effectiveness of the combined action of ultrasound with alkaline pretreatment to improve the accessibility to cellulose in this important step of the ethanol production process from biomass.


Assuntos
Agave/química , Celulose/química , Hidróxido de Sódio/química , Sonicação/métodos , Etanol/química , Hidrólise , Lignina/química , Polissacarídeos/química
18.
Ultrason Sonochem ; 50: 182-187, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30287181

RESUMO

In this work, an ultrasonic-assisted supramolecular based on solidification of floating organic drop microextraction (UA-SM-SFO-ME) was developed as a green method for preconcentration of methadone prior to gas chromatography-mass spectrometry (GC-MS). The supramolecular solvent aggregates containing reverse micelles of 1-dodecanol in tetrahydrofuran (THF) were formed by ultrasonication that subsequently dispersed in the sample solution. Ultrasonic waves caused the fast formation of supramolecular solvent aggregates. In this work, ultrasonication was used in two phases: First phase, the formation of reverse micelles and the second phase, the dispersion of supramolecular solvent in the sample solution. Actually, ultrasonication was basic of this presented work. In order to provide the highest extraction efficiency, the influence of various parameters on the method performance (supramolecular solvent type and volume, disperser solvent condition, pH, extraction time and salt concentration) was investigated. Based on the obtained optimum conditions, the limits of detection (LODs) and the limits of quantitation (LOQs) were obtained 0.5-1.2 µg L-1 and 1.2-2.5 µg L-1 with preconcentration factors in the range of 182-191, in water and biological samples, respectively. Subsequently, the method was assessed for preconcentration of the methadone in human plasma and saliva samples.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Microextração em Fase Líquida/métodos , Metadona/análise , Metadona/sangue , Compostos Orgânicos/química , Saliva/química , Ondas Ultrassônicas , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Micelas , Reprodutibilidade dos Testes , Solventes/química
19.
Ultrason Sonochem ; 40(Pt A): 221-229, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28946419

RESUMO

Nowadays, the attention of both academic and industrial research is paid to the novel materials based on renewable organic resources. Sodium lignosulphonate (SLS) is selected in this study to synthesize novel superabsorbent hydrogels by ultrasonic polymerization. The structure, morphology and stability of SLS-based hydrogel were confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Under the optimal condition, SLS-based hydrogel possesses the water absorbency of 1328g·g-1 in distilled water and 110g·g-1 in 0.9wt% NaCl solution. In addition, the prepared SLS-hydrogel as an adsorbent was applied to remove Ni2+ from an aqueous solution in virtue of its low cost and favorable adsorption capacity. The various experimental conditions that influence the adsorption capacity were investigated such as temperature (20-60°C), pH (2.0-7.0), contact time (0-360min) and initial concentration of the Ni2+ solution (100-600mg·L-1). Then the adsorption capability could reach 293mg·g-1 under optimal conditions. The results revealed that the adsorption behavior is spontaneous and endothermic. Furthermore, it was observed that the adsorption mechanism and adsorption equilibrium data obeyed pseudo-second-order kinetic and Freundlich models.

20.
Ultrason Sonochem ; 40(Pt A): 265-270, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28946424

RESUMO

An efficient preconcentration technique based on ultrasonic-assisted ionic liquid-based dual microextraction (UA-ILDµE) method has been developed to preconcentrate the lead (Pb+2) in ground and stored rain water. In the current proposed method, Pb+2 was complexed with a chelating agent (dithizone), whereas an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was used for extraction purpose. The ultrasonic irradiation and electrical shaking system were applied to enhance the dispersion and extraction of Pb+2 complex in aqueous samples. For second phase, dual microextraction (DµE phase), the enriched Pb+2 complex in ionic liquid, extracted back into the acidic aqueous solution and finally determined by flame atomic absorption spectrometry. Some major analytical parameters that influenced the extraction efficiency of developed method, such as pH, concentration of ligand, volume of ionic liquid and samples, time of shaking in thermostatic electrical shaker and ultrasonic bath, effect of back extracting HNO3 volume, matrix effect, centrifugation time and rate were optimized. At the sample volume of 25mL, the calculated preconcentration factor was 62.2. The limit of detection of proposed procedure for Pb+2 ions was found to be 0.54µgL-1. The validation of developed method was performed by the analysis of certified sample of water SRM 1643e and standard addition method in a real water sample. The extraction recovery of Pb+2 was enhanced≥2% with shaking time of 80s in ultrasonic bath as compared to used thermostatic electrical shaker, where for optimum recovery up to 10min was required. The developed procedure was successfully used for the enrichment of Pb+2 in ground and stored rain water (surface water) samples of an endemic region of Pakistan. The resulted data indicated that the ground water samples were highly contaminated with Pb+2, while some of the surface water samples were also have higher values of Pb+2 than permissible limit of WHO. The concentration of Pb+2 in surface and ground water samples was found in the range of 17.5-24.5 and 25.6-99.1µgL-1 respectively.

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