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1.
J Strength Cond Res ; 36(4): 941-947, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35319000

RESUMO

ABSTRACT: Huang, Z-H, Ma, CZ-H, Wang, L-K, Wang, X-Y, Fu, S-N, and Zheng, Y-P. Real-time visual biofeedback via wearable ultrasound imaging can enhance the muscle contraction training outcome of young adults. J Strength Cond Res 36(4): 941-947, 2022-Real-time ultrasound imaging (RUSI) can serve as visual biofeedback to train deep muscle contraction in clinical rehabilitative settings. However, its effectiveness in resistance training in sports/fitness fields remains unexplored. This article introduced a newly developed wearable RUSI system that provided visual biofeedback of muscle thickening and movement and reported its effectiveness in improving the training outcomes of muscle thickness change (%) during dynamic contraction. Twenty-five healthy young men participated and performed pec fly exercise both with and without RUSI biofeedback. Statistical analysis was conducted to examine the reliability of the measurements and the immediate effects of (a) RUSI biofeedback of muscle contraction and (b) training intensity (50 vs. 80% of 1-repetition maximum [1RM]) on the pectoralis major (PMaj) thickness change measured by ultrasound images. In addition to significantly high inter-contraction reliability (ICC3,1 > 0.97), we observed significantly increased PMaj thickness change for both training intensities upon receiving biofeedback in subjects, compared with without biofeedback (p < 0.001). We also observed significantly larger PMaj thickness change at 80% of 1RM compared with 50% of 1RM (p = 0.023). The provision of visual biofeedback using RUSI significantly enlarged the magnitude of PMaj thickness change during pec fly exercises, potentially indicating that RUSI biofeedback could improve the ability of targeted muscle contraction of PMaj in healthy young adults. To our knowledge, this study has pioneered in applying RUSI as a form of biofeedback during weight training and observed positive effectiveness. Future iterations of the technique will benefit more subject groups, such as athletes and patients with neuromuscular disorders.


Assuntos
Contração Muscular , Dispositivos Eletrônicos Vestíveis , Biorretroalimentação Psicológica , Humanos , Contração Muscular/fisiologia , Reprodutibilidade dos Testes , Ultrassonografia/métodos , Adulto Jovem
2.
Sensors (Basel) ; 19(1)2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30621103

RESUMO

BACKGROUND: Motion capture and analyzing systems are essential for understanding locomotion. However, the existing devices are too cumbersome and can be used indoors only. A newly-developed wearable motion capture and measurement system with multiple sensors and ultrasound imaging was introduced in this study. METHODS: In ten healthy participants, the changes in muscle area and activity of gastrocnemius, plantarflexion and dorsiflexion of right leg during walking were evaluated by the developed system and the Vicon system. The existence of significant changes in a gait cycle, comparison of the ankle kinetic data captured by the developed system and the Vicon system, and test-retest reliability (evaluated by the intraclass correlation coefficient, ICC) in each channel's data captured by the developed system were examined. RESULTS: Moderate to good test-retest reliability of various channels of the developed system (0.512 ≤ ICC ≤ 0.988, p < 0.05), significantly high correlation between the developed system and Vicon system in ankle joint angles (0.638R ≤ 0.707, p < 0.05), and significant changes in muscle activity of gastrocnemius during a gait cycle (p < 0.05) were found. CONCLUSION: A newly developed wearable motion capture and measurement system with ultrasound imaging that can accurately capture the motion of one leg was evaluated in this study, which paves the way towards real-time comprehensive evaluation of muscles and joint motions during different activities in both indoor and outdoor environments.


Assuntos
Locomoção/fisiologia , Músculo Esquelético/fisiologia , Caminhada/fisiologia , Dispositivos Eletrônicos Vestíveis , Adulto , Fenômenos Biomecânicos/fisiologia , Feminino , Marcha/fisiologia , Humanos , Masculino , Monitorização Fisiológica
3.
Angew Chem Int Ed Engl ; 58(28): 9443-9447, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31090130

RESUMO

Featuring the simultaneous generation of a library of compounds from a certain intermediate, divergent synthesis has found increasing applications in the construction of natural products and potential medicines. Inspired by this approach, presented herein is a general strategy to introduce functionality, in a divergent manner, into covalent organic frameworks (COFs). This modular protocol includes two stages of covalent assembly, through which functional COFs can be constructed by a three-step transformation of a key platform molecule, such as 4,7-dibromo-2-chloro-1H-benzo[d]imidazole (DBCBI). Constructed herein are four types of chiral COFs (CCOFs) from DBCBI by nucleophilic substitution, Suzuki coupling, and imine formation. The unique array of eight isoframework CCOFs allowed investigation of their catalytic performance and structure-activity relationship in an asymmetric amination reaction.

4.
J Am Chem Soc ; 140(13): 4623-4631, 2018 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-29584421

RESUMO

The structural uniqueness of covalent organic frameworks (COFs) has brought these new materials great potential for advanced applications. One of the key aspects yet to be developed is how to improve the robustness of covalently linked reticular frameworks. In order to make the best use of π-conjugated structures, we develop herein a "killing two birds with one stone" strategy and construct a series of ultrastable benzoxazole-based COFs (denoted as LZU-190, LZU-191, and LZU-192) as metal-free photocatalysts. Benefiting from the formation of benzoxazole rings through reversible/irreversible cascade reactions, the synthesized COFs exhibit permanent stability in the presence of strong acid (9 M HCl), strong base (9 M NaOH), and sunlight. Meanwhile, reticulation of the benzoxazole moiety into the π-conjugated COF frameworks decreases the optical band gap and therefore increases the capability for visible-light absorption. As a result, the excellent photoactivity and unprecedented recyclability of LZU-190 (for at least 20 catalytic runs, each with a product yield of 99%) have been illustrated in the visible-light-driven oxidative hydroxylation of arylboronic acids to phenols. This contribution represents the first report on the photocatalytic application of benzoxazole-based structures, which not only sheds new light on the exploration of robust organophotocatalysts from small molecules to extended frameworks but also offers in-depth understanding of the structure-activity relationship toward practical applications of COF materials.

5.
Mol Reprod Dev ; 84(11): 1140-1154, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28805353

RESUMO

Granulosa cells (GCs) play an important role in ovarian follicle growth, development, and follicular atresia. In the present study, we investigated the effects of Melatonin on bovine GCs, and asked if MTNR1A was involved in their response to this indole hormone. Our results indicated that Melatonin inhibited GC apoptosis by up-regulating the expression of BCL2, BCL-XL, GPX4, and SOD1, and down-regulating the expression of BAX, CASP3, and TP53. Moreover, Melatonin modulated bovine GC function by decreasing the expression of INHA, INHBB, FSHR, and TGFBR3, and the abundance of Inhibin ß and Activin B, while increasing the expression of LHR, INHBA, and secretion of progesterone by GCs. In contrast, knockdown of MTNR1A significantly increased the expression of BAX, CASP3, TP53, INHA, FSHR, and TGFBR3, as well as Inhibin ß abundance, while decreasing the expression of BCL2, GPX4, SOD1, and LHR, and production of progesterone and estradiol; no effect was observed on the expression of BCL-XL, INHBA, or INHBB. These results suggest that Melatonin and MTNR1A play an important role in modulating bovine GC function by regulating cellular progression, apoptosis, hormones secretion, and reproduction-related genes. Furthermore, altered expression of MTNR1A could affect how bovine GCs respond to Melatonin.


Assuntos
Apoptose/efeitos dos fármacos , Células da Granulosa/metabolismo , Melatonina/farmacologia , Receptor MT1 de Melatonina/metabolismo , Animais , Bovinos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa Peroxidase/biossíntese , Células da Granulosa/citologia , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Receptores do LH/biossíntese , Superóxido Dismutase-1/biossíntese , Proteína bcl-X/biossíntese
6.
J Refract Surg ; 30(11): 785-91, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25291757

RESUMO

PURPOSE: To introduce several new ocular biomechanical parameters for comparison between keratoconic and normal eyes using an analysis method based on corneal dynamic deformation video recorded by corneal visualization Scheimpflug technology (Corvis ST; Oculus Optikgeräte GmbH, Wetzlar, Germany). METHODS: This comparative study comprised 52 keratoconic eyes of 43 patients with keratoconus and 52 normal eyes of 52 controls. An analysis method (PolyU [Labview 2009; National Instrument, Austin, TX]) was developed to introduce several new ocular biomechanical parameters and to compare the difference between keratoconic and normal eyes. The repeatability of the new parameters measurement was evaluated and compared with the Corvis ST measurement. Receiver operating characteristic curves were used to establish a cutoff value for the new biomechanical parameters. RESULTS: Intraclass correlation coefficients of the deformation amplitude, peak distance, corneal concave radius of curvature, maximum deformation area, maximum corneal inward velocity and outward velocity (Vin, max and Vout, max) were high in both the keratoconic and normal eyes (all intraclass correlation coefficients > 0.75). The measurement agreement of the PolyU analysis method and Corvis ST was good. Most of the biomechanical parameters of patients with keratoconus were significantly different from those of the controls. In the receiver operating characteristic analysis, the Vin, max was the best predictive parameter with an area under the curve of 0.79. CONCLUSIONS: The corneal deformation video recorded by the Corvis ST provides useful information for the study of ocular biomechanics. Most of the new ocular biomechanical parameters were significantly different between keratoconic and normal eyes. Further research is needed to develop more comprehensive clinical applications with these new ocular biomechanical parameters.


Assuntos
Córnea/fisiopatologia , Diagnóstico por Imagem/métodos , Técnicas de Diagnóstico Oftalmológico , Elasticidade/fisiologia , Ceratocone/fisiopatologia , Adolescente , Adulto , Fenômenos Biomecânicos/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Gravação em Vídeo , Adulto Jovem
7.
Water Sci Technol ; 69(9): 1859-66, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24804660

RESUMO

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm(3) had the best drying performance at each level of temperature, which could save 35-45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm(3) was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.


Assuntos
Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Água/química , Dessecação/métodos , Modelos Teóricos
8.
Artigo em Zh | MEDLINE | ID: mdl-25726610

RESUMO

Five hundred and six fresh fecal samples were collected from Lu'an, Fuyang, Suzhou, Chizhou, Wuhu, Chuzhou and Bozhou in Anhui Province, and detected firstly by direct smear microscopy. The microscopy-positive samples were amplified by nested PCR targeting the triosephosphate isomerase (TPI) and glutamate dehydrogenase(GDH) genes. The positive PCR products were sequenced in both directions. The sequences were analyzed by ClustalX 1.81 for sequence alignment and the neighbor-joining trees were constructed by Mega 5.05. Thirty-two out of 506 fecal specimens were diagnosed as Giardia-positive by microscopy with an infection rate of 6.3%. 23 and 16 of the samples were typed as assemblage E by the TPI (530 bp) and GDH (450 bp) genes, respectively. These findings indicated that there was a different distribution of subtypes of assemblage E in different areas. The zoonosis genotypes such as assemblage A or B was not found in the present study.


Assuntos
Giardia lamblia/genética , Giardia lamblia/isolamento & purificação , Giardíase/veterinária , Doenças das Cabras/parasitologia , Animais , Sequência de Bases , Fezes , Genótipo , Giardíase/epidemiologia , Glutamato Desidrogenase , Cabras , Reação em Cadeia da Polimerase , Prevalência , Alinhamento de Sequência , Triose-Fosfato Isomerase , Zoonoses
9.
Diagnostics (Basel) ; 14(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38248066

RESUMO

Transient elastography (TE), recommended by the WHO, is an established method for characterizing liver fibrosis via liver stiffness measurement (LSM). However, technical barriers remain towards point-of-care application, as conventional TE requires wired connections, possesses a bulky size, and lacks adequate imaging guidance for precise liver localization. In this work, we report the design, phantom validation, and clinical evaluation of a palm-sized TE system that enables simultaneous B-mode imaging and LSM. The performance of this system was validated experimentally using tissue-equivalent reference phantoms (1.45-75 kPa). Comparative studies against other liver elastography techniques, including conventional TE and two-dimensional shear wave elastography (2D-SWE), were performed to evaluate its reliability and validity in adults with various chronic liver diseases. Intra- and inter-operator reliability of LSM were established by an elastography expert and a novice. A good agreement was observed between the Young's modulus reported by the phantom manufacturer and this system (bias: 1.1-8.6%). Among 121 patients, liver stiffness measured by this system and conventional TE were highly correlated (r = 0.975) and strongly agreed with each other (mean difference: -0.77 kPa). Inter-correlation of this system with conventional TE and 2D-SWE was observed. Excellent-to-good operator reliability was demonstrated in 60 patients (ICCs: 0.824-0.913). We demonstrated the feasibility of employing a fully integrated phased array probe for reliable and valid LSM, guided by real-time B-mode imaging of liver anatomy. This system represents the first technical advancement toward point-of-care liver fibrosis assessment. Its small footprint, along with B-mode guidance capability, improves examination efficiency and scales up screening for liver fibrosis.

10.
J Biomech Eng ; 135(10): 101009-8, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23897493

RESUMO

An evaluation of wound mechanics is crucial in reflecting the wound healing status. The present study examined the biomechanical properties of healing rat skin wounds in vivo and ex vivo. Thirty male Sprague-Dawley rats, each with a 6 mm full-thickness circular punch biopsied wound at both posterior hind limbs were used. The mechanical stiffness at both the central and margins of the wound was measured repeatedly in five rats over the same wound sites to monitor the longitudinal changes over time of before wounding, and on days 0, 3, 7, 10, 14, and 21 after wounding in vivo by using an optical coherence tomography-based air-jet indentation system. Five rats were euthanized at each time point, and the biomechanical properties of the wound tissues were assessed ex vivo using a tensiometer. At the central wound bed region, the stiffness measured by the air-jet system increased significantly from day 0 (17.2%), peaked at day 7 (208.3%), and then decreased progressively until day 21 (40.2%) as compared with baseline prewounding status. The biomechanical parameters of the skin wound samples measured by the tensiometer showed a marked reduction upon wounding, then increased with time (all p < 0.05). On day 21, the ultimate tensile strength of the skin wound tissue approached 50% of the normal skin; while the stiffness of tissue recovered at a faster rate, reaching 97% of its prewounded state. Our results suggested that it took less time for healing wound tissues to recover their stiffness than their maximal strength in rat skin. The stiffness of wound tissues measured by air-jet could be an indicator for monitoring wound healing and contraction.


Assuntos
Teste de Materiais/métodos , Fenômenos Mecânicos , Pele/lesões , Cicatrização , Animais , Fenômenos Biomecânicos , Masculino , Ratos , Ratos Sprague-Dawley , Pele/citologia , Resistência à Tração
11.
Biosensors (Basel) ; 12(5)2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35624650

RESUMO

Abnormal muscle tone and muscle weakness are related to gait asymmetry in stroke survivors. However, the internal muscle morphological changes that occur during walking remain unclear. To address this issue, this study investigated the muscle activity of the tibialis anterior (TA) and medial gastrocnemius (MG) of both the paretic and non-paretic sides during walking in nine stroke survivors, by simultaneously capturing electromyography (EMG), mechanomyography (MMG), and ultrasound images, and using a validated novel wearable ultrasound imaging and sensing system. Statistical analysis was performed to examine the test−retest reliability of the collected data, and both the main and interaction effects of each "side" (paretic vs. non-paretic) and "gait" factors, in stroke survivors. This study observed significantly good test−retest reliability in the collected data (0.794 ≤ ICC ≤ 0.985), and significant differences existed in both the side and gait factors of the average TA muscle thickness from ultrasound images, and in the gait factors of TA and MG muscle's MMG and EMG signals (p < 0.05). The muscle morphological characteristics also appeared to be different between the paretic and non-paretic sides on ultrasound images. This study uncovered significantly different internal muscle contraction patterns between paretic and non-paretic sides during walking for TA (7.2% ± 1.6%) and MG (5.3% ± 4.9%) muscles in stroke survivors.


Assuntos
Acidente Vascular Cerebral , Dispositivos Eletrônicos Vestíveis , Tornozelo , Humanos , Músculo Esquelético/diagnóstico por imagem , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/diagnóstico por imagem , Sobreviventes , Tecnologia , Ultrassonografia , Caminhada
12.
Mol Biol Rep ; 37(7): 3327-34, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19885739

RESUMO

Annexins constitute a family of multifunction and structurally related proteins. These proteins are ubiquitous in the plant kingdom, and are important calcium-dependent membrane-binding proteins that participate in the polar development of different plant regions such as rhizoids, root caps, and pollen tube tips. In this study, a novel cotton annexin gene (designated as GhFAnnx) was isolated from a fiber cDNA library of cotton (Gossypium hirsutum). The full-length cDNA of GhFAnnx comprises an open reading frame of 945 bp that encodes a 314-amino acid protein with a calculated molecular mass of 35.7 kDa and an isoelectric point of 6.49. Genomic GhFAnnx sequences from different cotton species, TM-1, Hai7124 and two diploid progenitor cottons, G. herbaceum (A-genome) and G. raimondii (D-genome) showed that at least two copies of the GhFAnnx gene, each with six exons and five introns in the coding region, were identified in the allotetraploid cotton genome. The GhFAnnx gene cloned from the cDNA library in this study was mapped to the chromosome 10 of the A-subgenome of the tetraploid cotton. Sequence alignment revealed that GhFAnnx contained four repeats of 70 amino acids. Semi-quantitative reverse transcriptase-polymerase chain reaction revealed that GhFAnnx is preferentially expressed in different developmental fibers but its expression is low in roots, stems, and leaves. Subcellular localization of GhFAnnx in onion epidermal cells and cotton fibers suggests that this protein is ubiquitous in the epidermal cells of onion, but assembles at the edge and the inner side of the apex of the cotton fiber tips with brilliant spots. In summary, GhFAnnx influences fiber development and is associated with the polar expansion of the cotton fiber during elongation stages.


Assuntos
Anexinas/genética , Anexinas/metabolismo , Fibra de Algodão , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Gossypium/crescimento & desenvolvimento , Gossypium/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Clonagem Molecular , DNA Complementar/genética , Perfilação da Expressão Gênica , Genes de Plantas , Gossypium/citologia , Proteínas de Fluorescência Verde/metabolismo , Especificidade de Órgãos/genética , Filogenia , Transporte Proteico , Proteínas Recombinantes de Fusão/metabolismo , Análise de Sequência de DNA , Frações Subcelulares/metabolismo , Tetraploidia
13.
PLoS One ; 13(11): e0207189, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30419001

RESUMO

The cornea is a soft, transparent, composite organic tissue, which forms the anterior outer coat of the eyeball. Although high myopia is increasing in prevalence worldwide and is known to alter the structure and biomechanical properties of the sclera, remarkably little is known about its impact on the biomechanics of the cornea. We developed and validated a novel optical-coherence-tomography-indentation probe-to measure corneal biomechanical properties in situ, in chicks having experimentally-induced high myopia, while maintaining intraocular pressure at levels covering the physiological range. We found that the cornea of highly myopic chicks was more steeply curved and softer, at all tested intraocular pressures, than that in contralateral, non-myopic eyes, or in age-matched normal, untreated eyes. These results indicate that the biomechanical properties of the cornea are altered in chicks developing experimentally-induced myopia.


Assuntos
Córnea/diagnóstico por imagem , Córnea/fisiopatologia , Miopia/diagnóstico por imagem , Miopia/fisiopatologia , Animais , Fenômenos Biomecânicos , Galinhas , Modelos Animais de Doenças , Pressão Intraocular , Tomografia de Coerência Óptica/instrumentação , Ultrassonografia
14.
Anim Sci J ; 89(9): 1271-1279, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29851189

RESUMO

Two trials were conducted to assess the effects of tributyrin (TB) supplementation on ruminal microbial protein yield and fermentation characteristics in adult sheep. In an in vitro trial, substrate was made to offer TB at 0, 2, 4, 6, and 8 g/kg on a dry matter (DM) basis and incubated for 48 hr. In an in vivo trial, 45 adult ewes were randomly assigned by initial body weight (55 ± 5 kg) to five treatments of nine animals over an 18-day period. Total mixed ration was made to offer TB to ewes at 0, 2, 4, 6, and 8 g/kg on a DM basis. The in vitro trial showed that TB enhanced apparent degradation of DM (p = .009), crude protein (p < .001), neutral detergent fiber (p = .007) and acid detergent fiber (p = .010) and increased methanogenesis (p < .001), respectively. The in vivo trial showed that TB decreased DM intake (p < .001) and enhanced rumen microbial N synthesis (p < .001), respectively. Both in vitro and in vivo trials showed that TB increased total volatile fatty acid concentration and enhanced fibrolytic enzyme activity. The results indicated that TB might exert positive effects on microbial protein yield and fermentation in the rumen.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Dieta/veterinária , Suplementos Nutricionais , Fermentação/fisiologia , Rúmen/metabolismo , Ovinos/metabolismo , Ovinos/fisiologia , Triglicerídeos/administração & dosagem , Erros Inatos do Metabolismo dos Aminoácidos , Animais , Proteínas de Bactérias/metabolismo , Hipoplasia do Esmalte Dentário , Diabetes Mellitus , Nanismo , Ácidos Graxos Voláteis/metabolismo , Feminino , Técnicas In Vitro , Deficiência Intelectual , Microcefalia , Rúmen/enzimologia , Rúmen/microbiologia , Triglicerídeos/farmacologia
15.
J Biophotonics ; 9(5): 454-63, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26755237

RESUMO

The paper presents a novel analysis method of corneal elasticity and viscosity based on corneal visualization Scheimpflug technology (CorVis ST) for keratoconus diagnosis. Methods for air puff force measurement and corneal imaging boundary extraction were proposed. Corneal biomechanical properties, described as tangent stiffness coefficient (STSC ) and energy absorbed area (Aabsorbed ), were assessed using the curves of the applied air puff force with corneal displacement to form a loading-unloading cycle. Twenty-five patients with keratoconus and 34 healthy control subjects, matched for intraocular pressure (IOP), were enrolled in this prospective study. The results showed that the intraclass correlation coefficients (ICC) of the STSC and Aabsorbed were 0.941 and 0.878 in Healthy group; and were 0.891 and 0.809 in Keratoconus group, respectively. Both STSC and Aabsorbed of keratoconus patients were significantly different from that of controls (both probability value P < 0.001). ROC curve analysis showed that the area under curve for STSC was 0.918 and for Aabsorbed was 0.894, which reached a good level of predictive accuracy for detecting keratoconus. Our results demonstrated that this new analysis method could be used to characterize the biomechanical properties of corneas. (a) The air puff force of CorVis ST was measured by a custom-designed force detection system. (b) Corneal displacement was extracted from CorVis ST using a proposed imaging analysis. (c) With the utilization of the air puff force and corneal dynamic displacement, an analysis method was developed to introduce new corneal biomechanical parameters - STSC and Aabsorbed .


Assuntos
Córnea/fisiologia , Processamento de Imagem Assistida por Computador , Ceratocone/diagnóstico por imagem , Fenômenos Biomecânicos , Estudos de Casos e Controles , Elasticidade , Humanos , Estudos Prospectivos , Viscosidade
16.
Ultrasonics ; 71: 20-28, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27262352

RESUMO

Biomechanical properties are potential information for the diagnosis of corneal pathologies. An ultrasound indentation probe consisting of a load cell and a miniature ultrasound transducer as indenter was developed to detect the force-indentation relationship of the cornea. The key idea was to utilize the ultrasound transducer to compress the cornea and to ultrasonically measure the corneal deformation with the eyeball overall displacement compensated. Twelve corneal silicone phantoms were fabricated with different stiffness for the validation of measurement with reference to an extension test. In addition, fifteen fresh porcine eyes were measured by the developed system in vitro. The tangent moduli of the corneal phantoms calculated using the ultrasound indentation data agreed well with the results from the tensile test of the corresponding phantom strips (R(2)=0.96). The mean tangent moduli of the porcine corneas measured by the proposed method were 0.089±0.026MPa at intraocular pressure (IOP) of 15mmHg and 0.220±0.053MPa at IOP of 30mmHg, respectively. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) of tangent modulus were 14.4% and 0.765 at 15mmHg, and 8.6% and 0.870 at 30mmHg, respectively. The preliminary study showed that ultrasound indentation could be applied to the measurement of corneal tangent modulus with good repeatability and improved measurement accuracy compared to conventional surface displacement-based measurement method. The ultrasound indentation can be a potential tool for the corneal biomechanical properties measurement in vivo.


Assuntos
Córnea/diagnóstico por imagem , Córnea/fisiologia , Ultrassonografia/métodos , Animais , Fenômenos Biomecânicos , Módulo de Elasticidade , Desenho de Equipamento , Pressão Intraocular , Imagens de Fantasmas , Suínos , Transdutores
17.
J Hazard Mater ; 286: 493-502, 2015 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-25603298

RESUMO

Improving the reduction kinetics is crucial in the electroreduction process of Cr(VI). In this study, we developed a novel adsorption-electroreduction system for accelerated removal of Cr(VI) by employing reticulated vitreous carbon electrode modified with sulfuric acid-glycine co-doped polyaniline (RVC/PANI-SA-GLY). Firstly, response surface methodology confirmed the optimum polymerization condition of co-doped polyaniline for modifying electrodes (Aniline, sulfuric acid and glycine, respectively, of 0.2 mol/L, 0.85 mol/L, 0.93 mol/L) when untraditional dopant glycine was added. Subsequently, RVC/PANI-SA-GLY showed higher Cr(VI) removal percentages in electroreduction experiments over RVC electrode modified with sulfuric acid doped polyaniline (RVC/PANI-SA) and bare RVC electrode. In contrast to RVC/PANI-SA, the improvement by RVC/PANI-SA-GLY was more significant and especially obvious at more negative potential, lower initial Cr(VI) concentration, relatively less acidic solution and higher current densities, best achieving 7.84% higher removal efficiency with entire Cr(VI) eliminated after 900 s. Current efficiencies were likewise enhanced by RVC/PANI-SA-GLY under quite negative potentials. Fourier transform infrared (FTIR) and energy dispersive spectrometer (EDS) analysis revealed a possible adsorption-reduction mechanism of RVC/PANI-SA-GLY, which greatly contributed to the faster reduction kinetics and was probably relative to the absorption between protonated amine groups of glycine and HCrO4(-). Eventually, the stability of RVC/PANI-SA-GLY was proven relatively satisfactory.


Assuntos
Compostos de Anilina/química , Carbono/química , Cromo/química , Glicina/química , Ácidos Sulfúricos/química , Adsorção , Eletrodos , Oxirredução , Eliminação de Resíduos Líquidos/métodos
18.
Ultrasonics ; 54(5): 1395-400, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24613414

RESUMO

Moisturizing creams and lotions are commonly used in daily life for beauty and treatment of different skin conditions such as dryness and wrinkling, and ultrasound stimulation has been used to enhance the delivery of ingredients into skin. However, there is a lack of convenient methods to study the effect of ultrasound stimulation on lotion absorption by skin in vivo. Ultrasound biomicroscopy was adopted as a viable tool in this study to investigate the effectiveness of ultrasound stimulation on the enhancement of lotion delivery into skin. The forearm skin of 10 male and 10 female young subjects was tested at three different sites, including two lotion treatment sites with (Ultrasound Equipment - UE ON) and without (UE OFF) ultrasound stimulation and a control site without any lotion treatment. 1 MHz ultrasound with a duty cycle of 1.7%, a spatial peak temporal peak pressure of 195 kPa and an average power of 0.43 W was used for the stimulation. The skin thickness before, immediately after (0 min), and 15 and 30 min after the treatment was measured by an ultrasound biomicroscopic system (55 MHz). It was found that the skin thickness significantly increased immediately after the lotion treatment for both UE ON (from 1.379 ± 0.187 mm to 1.466 ± 0.182 mm, p<0.001) and UE OFF (from 1.396 ± 0.193 mm to 1.430 ± 0.194 mm, p<0.001) groups. Further comparison between the two groups revealed that the skin thickness increase of UE ON group was significantly larger than that of UE OFF group (6.5 ± 2.4% vs. 2.5 ± 1.3%, p<0.001). Furthermore, it was disclosed that the enhancement of lotion delivery by ultrasound stimulation was more effective for the female subjects than the male subjects (7.6 ± 2.3% vs. 5.4 ± 2.0% immediately after treatment, p=0.017). In conclusion, this study demonstrated that ultrasound biomicroscopy was a feasible method for studying the effectiveness of lotion treatment in vivo, and ultrasound stimulation was effective to enhance the rate of lotion absorption into skin.


Assuntos
Técnicas Cosméticas/instrumentação , Emolientes/administração & dosagem , Microscopia Acústica , Pele/efeitos dos fármacos , Pele/diagnóstico por imagem , Absorção , Braço , Desenho de Equipamento , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
19.
J Hazard Mater ; 275: 63-71, 2014 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-24853137

RESUMO

Organobentonite-photocatalysis technology was applied to pretreat aging leachate containing refractory pollutants. The organobentonite was synthesized by organic modifier cetyltrimethylammonium bromide (CTMAB) and natural bentonite. In characterization experiments, we could confirm that organic functional groups of cetyltrimethylammonium (CTMA(+)) cations were successfully loaded on the surface of bentonite. The combination of CTMAB2.5 adsorption and TiO2 photocatalysis was superior to either running separately. Furthermore, removal efficiency of simultaneously utilizing CTMAB2.5 and TiO2 was better than them in succession. The combination technology was feasible and was optimized by response surface methodology (RSM) with COD and NH3-N removal rate as the target responses. The optimal operation conditions calculated from the regression equations were CTMAB2.5 dosage of 7.5 g/L, pH at 3.5, TiO2 dosage of 1.63 g/L, and reaction time for 60.02 min, which maintained the removal of COD and NH3-N at 82% and 37%, respectively.


Assuntos
Bentonita/química , Compostos de Cetrimônio/química , Titânio/química , Raios Ultravioleta , Poluentes Químicos da Água/química , Adsorção , Amônia/química , Análise da Demanda Biológica de Oxigênio , Catálise , Cetrimônio , Titânio/efeitos da radiação , Instalações de Eliminação de Resíduos
20.
Huan Jing Ke Xue ; 33(2): 511-7, 2012 Feb.
Artigo em Zh | MEDLINE | ID: mdl-22509590

RESUMO

The experiment was carried out in a sequencing batch reactor (SBR), using granular sludge with 90% shortcut nitrification accumulation ratio, which had been cultivated by the laboratory to seed the reactor. The effects of temperature on characteristics, stability, nitrogen conversion properties and activity of short-cut nitrification granular sludge were investigated. The results show that the temperature has a significant influence on structure and short-cut nitrification performance of short-cut nitrification granular sludge. 30 degrees C was the optimum temperature for shortcut nitrification granular sludge cultivation, and the granules were more compact which led better flocculation and settleability. SVI and average diameter of sludge reached up to 39 mL x g(-1) and 3.03 mm, respectively. The nitrification accumulation was maintained at 96.17% during this period. When the temperature was at 25 degrees C, the granules changed to a loose-structure along with the electronegativity increased as well as the hydrophobicity decreased, which was due to the increase of EPS and decreased ratio of protein to polysaccharide. The granules disintegrated during this period, at the same time, the nitrification accumulation ratio was below 35%. It can be seen that the shortcut nitrification performance was destroyed. At 15 degrees C, the shortcut nitrification sludge also disintegrated and had a looser structure. However, the oxygen penetration depth increased at a lower temperature, which made the relative quantity of ammonia oxidizing bacteria (AOB) in reactor increased, the nitrification accumulation was around 68% ultimately.


Assuntos
Reatores Biológicos/microbiologia , Nitrificação , Esgotos/química , Temperatura , Eliminação de Resíduos Líquidos/métodos , Floculação , Nitritos/isolamento & purificação , Nitritos/metabolismo , Nitrogênio/isolamento & purificação , Nitrogênio/metabolismo
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