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1.
Org Lett ; 26(2): 553-558, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38181402

RESUMO

α,ß-Unsaturated carbonyls are essential structural motifs for nucleophiles of disease-related proteins. Methods for stereoselective functionalizations at the α-position include the Morita-Baylis-Hillman, Negishi, Sonogashira, Stille, and Rauhut-Currier reactions. Described here is a method for the diastereodivergent α-homoallylation of cyclic enones via a sequence of conjugate addition, aldol condensation, and diastereoselective [3,3]-sigmatropic rearrangement. Mechanistic investigations revealed that the [3,3]-sigmatropic rearrangement proceeds with transfer of chirality. These inspire a photocatalyzed olefin isomerization of the aldol condensation product leading to a highly diastereoselective [3,3]-sigmatropic rearrangement to furnish the α-homoallylation of cyclic enones. Importantly, this photocatalyzed olefin isomerization/diastereoselective [3,3]-sigmatropic rearrangement reaction sequence permits a full stereocontrol of the exo-ß-position featuring an allyl group as a synthetic functional handle.

2.
Materials (Basel) ; 16(3)2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36770007

RESUMO

In this research, we studied the functional properties of CuCrO2, which is the most promising p-type transparent conductive oxide (TCO). The thin films were fabricated using a spin coating technique. The diffraction patterns were obtained with the help of X-ray diffractions, and the optical properties of absorption characteristics were studied using UV-visible absorption. The physical properties of film formation and surface morphology were analyzed using FESEM analysis. The aging properties were also analyzed with the help of various precursors with different aging times. The CuCrO2 thin films' functional properties were determined by using chelating agent and precursor solution aging times. The CuCrO2 thin films have better transmittance, resistance, figure of merit (FOM), and electrical conductivity. Moreover, the resistivity values of the CuCrO2 thin films are 7.01, 9.90, 12.54, 4.10, 2.42, and 0.35 Ω cm. The current research article covers the preparation of copper chromium delafossite thin films. These thin films can be suitable for hole transport layers in transparent optoelectronic devices.

3.
Materials (Basel) ; 15(24)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36556574

RESUMO

Hydrogen is the alternative renewable energy source for addressing the energy crisis, global warming, and climate change. Hydrogen is mostly obtained in the industrial process by steam reforming of natural gas. In the present work, CuCrO2 particles were attached to the surfaces of electrospun CeO2 nanofibers to form CeO2-CuCrO2 nanofibers. However, the CuCrO2 particles did not readily adhere to the surfaces of the CeO2 nanofibers, so a trace amount of SiO2 was added to the surfaces to make them hydrophilic. After the SiO2 modification, the CeO2 nanofibers were immersed in Cu-Cr-O precursor and annealed in a vacuum atmosphere to form CeO2-CuCrO2 nanofibers. The CuCrO2, CeO2, and CeO2-CuCrO2 nanofibers were examined by X-ray diffraction analysis, transmission electron microscopy, field emission scanning electron microscopy, scanning transmission electron microscope, thermogravimetric analysis, and Brunauer-Emmett-Teller studies (BET). The BET surface area of the CeO2-CuCrO2 nanofibers was 15.06 m2/g. The CeO2-CuCrO2 nanofibers exhibited hydrogen generation rates of up to 1335.16 mL min-1 g-cat-1 at 773 K. Furthermore, the CeO2-CuCrO2 nanofibers produced more hydrogen at lower temperatures. The hydrogen generation performance of these CeO2-CuCrO2 nanofibers could be of great importance in industry and have an economic impact.

4.
Materials (Basel) ; 15(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36556762

RESUMO

Hydrogen can be employed as an alternative renewable energy source in response to climate change, global warming, and the energy problem. Methanol gas steam reforming (SRM) is the major method used in industry to produce hydrogen. In the SRM process, the catalyst nature offers benefits such as low cost, simplicity, and quickness. In this work, delafossite copper yttrium oxide (CuYO2) nanofibers were successfully prepared by electrospinning. The prepared CuYO2 nanofibers have different physical and chemical properties including thermoelectric behavior. The electrospinning method was used to produce as-spun fibers and annealed in an air atmosphere to form Cu2Y2O5 fibers; then, Cu2Y2O5 fibers were annealed in a nitrogen atmosphere to form CuYO2 nanofibers. X-ray diffraction studies and thermogravimetric and transmission electron microscope analysis confirmed the formation of CuYO2 nanofibers. The CuYO2 nanofibers were applied to methanol steam reforming for hydrogen production to confirm their catalytic ability. The CuYO2 nanofibers exhibited high catalytic activity and the best hydrogen production rate of 1967.89 mL min-1 g-cat-1 at 500 °C. The highly specific surface area of CuYO2 nanofibers used in steam reforming reactions could have significant economic and industrial implications. The performance of these CuYO2 nanofibers in hydrogen generation could be very important in industries with a global economic impact. Furthermore, the H2 production performance increases at higher reaction temperatures.

5.
Chemosphere ; 301: 134458, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35452642

RESUMO

Spinel structured aluminates TAl2O4 (T = Mg, Zn, and Cu) were synthesized by a facile hydrothermal method. The resultant enhancement in the electrochemical behavior was achieved due to the covalent synergism among the elements coexisting together. Structural and morphological characterizations were performed by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and field emission scanning electron microscopy. MgAl2O4, ZnAl2O4 and CuAl2O4 has displayed same space group Fd3m of Laue class lattice type of the cubic structure as they were synthesized at same temperature (600 °C). CuAl2O4 spinel structure displayed a nanoneedle like structure along with the small sized cylindrical particles alongside to which CuAl2O4 spinel is combined with activated carbon (CuAl/C) and was applied to develop a facile sensor for the electrochemical detection of Acetaminophen (ACAP) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which exhibited maximum conductivity, and a substantial electroactive surface area. Finally, the defect-rich composite, CuAl/C, showed excellent sensor performance towards DPV with 21.5 nM limit of detection (LOD) in a wide linear working range of 0.199 µM-165.88 µM ACAP concentration, with a high sensitivity of 19.1221 µA µM-1cm2. Additionally, the sensor showed excellent recovery results in real-time analysis for environmental aquatic samples like industrial wastewater and Tuna Fish.


Assuntos
Óxido de Alumínio , Técnicas Eletroquímicas , Animais , Técnicas Eletroquímicas/métodos , Eletrodos , Óxido de Magnésio , Zinco
6.
J Xray Sci Technol ; 28(4): 739-750, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32597826

RESUMO

BACKGROUND: Although computed tomography (CT) is a powerful diagnostic imaging modality for diagnosing vascular diseases, it is some what risky to human health due to the high radiation dosage. Thus, CT vendors have developed low dose computed tomography (LDCT) aiming to solve this problem. Nowadays, LDCT has gradually become a main stream of CT examination. OBJECTIVE: This study aimed to assess the feasibility of LDCTAin an animal model and compare the imaging features and doses in two clinical scanners. METHODS: Twenty-two New Zealand rabbit head and neck CTA images pre- and post-contrast agent injection were performed using256-sliceand 64-slice CT scanners. The tube voltages used in the 256-slice and the 64-slice CTA were 70 kVp and 80 kVp, respectively. Quantitative images indices and radiation doses obtained from CTA in these two scanners were compared. RESULTS: More neck arterial vessels could be visualized in multi-planar reconstruction (MPR) CTA on the 256-slice CT scanner than on the 64-slice CT scanner. After contrast agent injection, all observed neck arterial vessels had higher CT numbers in 256-slice CTA than in 64-slice CTA. There was no significant difference in contrast-to-noise (CNR) of CTA images between these two scanners. CT dose index (CTDI) and dose length product (DLP) for the 256-slice CTA were lower than those for the 64-slice CTA. CONCLUSIONS: Low dose CTA of rabbits with 70 or 80 kVp is feasible in a 256-slice or a 64-slice CT scanner. The radiation dose from the 256-slice CTA was much lower than that from the 64-slice CTA with comparable SNR and CNR. The technique can be further applied in longitudinal monitoring of an animal stroke model in the future.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Cabeça/diagnóstico por imagem , Pescoço/diagnóstico por imagem , Animais , Angiografia por Tomografia Computadorizada/instrumentação , Meios de Contraste/uso terapêutico , Estudos de Viabilidade , Cabeça/irrigação sanguínea , Processamento de Imagem Assistida por Computador , Pescoço/irrigação sanguínea , Coelhos , Doses de Radiação , Razão Sinal-Ruído
7.
J Xray Sci Technol ; 27(5): 935-947, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31306147

RESUMO

BACKGROUND: Arterial embolism is a major cause of ischemic stroke. Currently, digital subtraction angiography (DSA) is the gold standard in clinical arterial embolization examinations. However, it is invasive and risky. OBJECTIVE: This study aims to longitudinally assess the progression of carotid artery embolism in middle cerebral artery occlusion animal model (MCAO) using magnetic resonance imaging (MRI) techniques. METHODS: Turbo spin echo (TSE), time of flight magnetic resonance angiography (TOF-MRA) and diffusion weighted magnetic resonance imaging (DWI) were used to evaluate the image characteristics of cerebral tissues at 1, 2, 3, 7, 14, 21 and 28 days after MCAO microsurgery on Sprague-Dawley (SD) rats. Quantitative analysis was performed and compared in MCAO hemisphere and contralateral normal hemisphere. Furthermore, pathologic section using triphenyl tetrazolium chloride (TTC) stain was performed as well. RESULTS: TOF-MRA showed carotid signal void in the embolism side, which is evidence of artery occlusion. The used MRI techniques showed that edema gradually dissipated within one week, but there was no significant change afterwards. The time-varying signal intensity of MRI techniques in MCAO hemisphere changed significantly, but there were no significant changes in contralateral normal hemisphere. Cerebral injury was also confirmed by analysis of pathology images. CONCLUSIONS: The MCAO animal model was successfully established on SD rats using the microsurgery to assess arterial embolization of intracranial tissue injury.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Modelos Animais de Doenças , Acidente Vascular Cerebral/diagnóstico por imagem , Angiografia Digital , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Lesões das Artérias Carótidas , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Estudos Longitudinais , Masculino , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/metabolismo , Sais de Tetrazólio/metabolismo
8.
J Xray Sci Technol ; 26(6): 997-1009, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30223421

RESUMO

BACKGROUND: Anesthesia may alter the cellular components contributing to the magnetic resonance imaging (MRI) signal intensities. Developing awake animal models to evaluate cerebral function has grown in importance. OBJECTIVE: To investigate a noninvasive strategy for dynamic MRI (dMRI) of awake rabbits during carbogen challenge. METHODS: A nonmetallic assistive device with a self-adhering wrap secure procedure was developed for the head fixation of awake rabbits. Multi-shot gradient echo echo-planar imaging sequence was applied for the dMRI on a 1.5 T clinical MRI scanner with a quadrature head coil. The carbogen challenge pattern was applied in a sequence of air - carbogen - air - carbogen - air. Twelve scans were performed for each block of carbogen challenge. T2-weighted fast-spin echo and T1-weighted gradient echo sequences were performed before and after dMRI to evaluate the head position shifts. The whole dMRI scan time was about 30 minutes. RESULTS: The position shift of 8 rabbits in the x-and y-direction was less than 3%. The average MRI signal intensities (SI) from the 8 rabbits during carbogen challenge was fitted well using exponential growth and decay functions. The average MRI SI increase due to carbogen inhaling was 1.51%. CONCLUSIONS: The proposed strategy for head dMRI on an awake rabbit during carbogen challenge is feasible.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/instrumentação , Restrição Física/instrumentação , Vigília/fisiologia , Animais , Encéfalo/fisiologia , Dióxido de Carbono/administração & dosagem , Desenho de Equipamento , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Oxigênio/administração & dosagem , Coelhos
9.
BMC Neurol ; 17(1): 192, 2017 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-28985720

RESUMO

BACKGROUND: The clinical features of Alzheimer's disease (AD) are related to brain network degeneration, and hyperhomocysteinemia is related to greater white matter hyperintensities. We investigated the changes in four diffusion tensor imaging parameters in the white matter of patients with early stage AD, examined their associations with homocysteine level, and tested the clinical significance of the diffusion tensor imaging parameters and homocysteine level in correlation analysis with cognitive test scores. METHODS: We enrolled 132 patients with AD and analyzed white matter (WM) macrostructural changes using diffusion tensor neuroimaging parameters including fractional anisotropy (FA), mean diffusion (MD), axial diffusivity (axial-D) and radial diffusivity (RD). Two neuroimaging post-processing analyses were performed to provide complementary data. First, we calculated 11 major bundle microstructural integrities using a WM parcellation algorithm, and correlated them with serum homocysteine levels to explore whether the fiber bundles were affected by homocysteine. Second, we used tract-based spatial statistics to explore the anatomical regions associated with homocysteine levels. Changes in cognitive test scores caused by homocysteine served as the major outcome factor. RESULTS: The results suggested that homocysteine levels did not have a direct impact on cross-sectional cognitive test scores, but that they were inversely correlated with renal function, B12 and folate levels. Topographies showing independent correlations with homocysteine in FA and MD were more diffusely located compared to the posterior brain regions in axial-D and RD. In the association bundle analysis, homocysteine levels were significantly correlated with the four diffusion parameters even after correcting for confounders, however no association between homocysteine and WM to predict cognitive outcomes was established. CONCLUSIONS: In our patients with AD, homocysteine levels were associated with renal dysfunction and decreased levels of vitamin B12 and folate, all of which require clinical attention as they may have been associated with impaired WM microstructural integrity and modulated cognitive performance in cross-sectional observations.


Assuntos
Doença de Alzheimer/fisiopatologia , Homocisteína/metabolismo , Substância Branca/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Anisotropia , Encéfalo/fisiopatologia , Estudos Transversais , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Masculino , Neuroimagem
10.
J Org Chem ; 82(15): 8213-8219, 2017 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-28691490

RESUMO

A facile formal synthesis to aphanorphine and its analogue is described, featuring Rh-catalyzed cyclohydrocarbonylation of 2-aminodihydronaphthalene to the bridged benzazepine core. Subsequent introduction of the methyl group and functional group transformation complete the synthesis of aphanorphine and its analogue over eight steps.


Assuntos
Benzazepinas/química , Hidrocarbonetos Aromáticos com Pontes/síntese química , Naftalenos/química , Compostos Organometálicos/química , Pirróis/síntese química , Ródio/química , Hidrocarbonetos Aromáticos com Pontes/química , Catálise , Estrutura Molecular , Pirróis/química , Estereoisomerismo
11.
Clin Colorectal Cancer ; 16(3): 187-194, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28209482

RESUMO

PURPOSE: We sought to test the effectiveness of the application of a tailored anterior saturation band (ASB) to improve the image quality of pelvic magnetic resonance imaging (MRI) for assessing rectal cancer. METHODS: A total of 165 patients with MRI assessment of rectal cancer between 2013 and 2015 were included. The image quality scores (4-point scale: 1, nondiagnostic through 4, excellent) of MRI without and with tailored ASBs were compared. Sensitivity, specificity, positive and negative predictive values, and accuracy of pelvic MRIs with and without a tailored ASB for T-staging in 65 patients with direct surgery and 67 patients with chemoradiotherapy before surgery were evaluated. RESULTS: Two independent raters exhibited moderate-to-excellent interobserver agreements (κ = 0.529-0.879) in the grading of MRI image quality. Overall, the quality scores of sagittal and axial T2-weighted images with tailored ASBs were significantly improved compared with MRIs without ASBs (3.5 ± 0.3 vs. 2.7 ± 0.8 [mean ± SD]; P < .001, and 3.6 ± 0.3 vs. 2.8 ± 0.8; P < .001, respectively). The application of tailored ASBs in MRIs improved the averaged accuracies for staging of ≤ T2, T3, and T4 tumors from 87.7%, 78.5%, and 90.8% to 93.1%, 86.9%, and 97.7%, respectively. In post-chemoradiotherapy MRI follow-ups, the use of tailored ASBs also improved the average accuracies for staging of yT0, yT1-2, yT3, and yT4 tumors from 80.6%, 73.1%, 73.9%, and 91.0%, to 85.8%, 82.9%, 85.1%, and 94.0%, respectively. CONCLUSIONS: Application of a tailored ASB in pelvic MRI is effective in substantially reducing motion artifacts, significantly upgrading image quality, and improving accuracies of rectal tumor staging.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias Retais/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Aesthetic Plast Surg ; 40(3): 435-45, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27125546

RESUMO

BACKGROUND: Capsular contracture is the most common complication of breast augmentation. Although numerous procedures are intended to prevent capsular contracture, their efficacy does not satisfy surgeons or patients. In the present study, we used shock waves to develop innovative protocols to treat capsular contracture in rabbits. METHODS: We used shock waves to treat capsular contracture in a rabbit model. Six clinical parameters were evaluated to determine the treatment efficacy of shock waves on the pathological histology of capsular contracture. Dual-flip-angle T1-mapping magnetic resonance imaging was used to confirm the pathological findings. RESULTS: Among the parameters, myxoid change, vascular proliferation, and lymphoplasma cell infiltration around the capsule increased more after treatment than they did in a control group. Capsular thickness, inner thinner collagen layer, and capsule wall collagen deposition decreased after shock wave treatment; only the inner thinner collagen layer and capsule wall collagen deposition changed significantly. The MRI findings for both scar thickness and water content were consistent with pathological biology findings. CONCLUSION: This was the first pilot study and trial to treat capsular contractures using shock waves. We found that shock waves can cause changes in the structure or the composition of capsular contracture. We conclude that the treatment could decrease water content, loosen structure, decrease collagen deposition, and might alleviate scar formation from capsular contracture. We believe that the treatment could be a viable remedy for capsular contractures. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Implantes de Mama/efeitos adversos , Ondas de Choque de Alta Energia/uso terapêutico , Contratura Capsular em Implantes/diagnóstico por imagem , Contratura Capsular em Implantes/terapia , Imageamento por Ressonância Magnética/métodos , Animais , Biópsia por Agulha , Modelos Animais de Doenças , Feminino , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Contratura Capsular em Implantes/patologia , Mamoplastia/efeitos adversos , Mamoplastia/métodos , Glândulas Mamárias Animais , Projetos Piloto , Coelhos , Distribuição Aleatória , Valores de Referência , Sensibilidade e Especificidade
13.
ACS Appl Mater Interfaces ; 7(31): 16923-31, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26140290

RESUMO

We present a polyvinylidene fluoride (PVDF) nanogenerator (NG) with advantages of direct writing and in situ poling via near-field electrospinning (NFES), which is completely location addressable and substrate independent. The maximum output voltage reached 20 V from the three layers piled NGs with serial connections, and the maximum output current can exceed 390 nA with the parallel integration setup. Linear superposition and switching polarity of current and voltage tests were validated by the authentic piezoelectric output. Nanofiber (NF)-based devices with a length ∼5 cm can be easily attached on the human finger under folding-releasing at ∼45°, and the output voltage and current can reach 0.8 V and 30 nA, respectively. This work based on NFs can potentially have a huge impact on harvesting various external sources from mechanical energies.


Assuntos
Fontes de Energia Elétrica , Músculo Esquelético/fisiologia , Nanotecnologia/métodos , Desenho de Equipamento , Dedos/fisiologia , Humanos , Movimento/fisiologia , Nanofibras/química , Nanofibras/ultraestrutura , Nanotecnologia/instrumentação , Polivinil/química
14.
Magn Reson Med Sci ; 14(3): 193-202, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25833269

RESUMO

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is widely used to diagnose cancer and monitor therapy. The maximum enhancement ratio (ERmax) obtained from the curve of signal intensity over time could be a biomarker to distinguish cancer from normal tissue or benign tumors. We evaluated the impact of flip angle (FA) and repetition time (TR) on the ERmax values of dynamic gadobutrol-enhanced MR imaging, obtaining T1-weighted (T1W) MR imaging of VX2 tumors using 2-dimensional fast spoiled gradient echo (2D FSPGR) with various FAs (30°, 60° and 90°) at 1.5 tesla before and after injection of 0.1 mmol/kg gadobutrol. In vivo study indicated significant differences between ERmax values and area under the ER-time curve (AUC100) of VX2 tumors and muscle tissue, with the highest ERmax and AUC100 at FA 90°. Computer simulation also demonstrated the ER as a strictly increasing monotonic function in the closed interval [0°, 90°] for a given TR when using T1W FSPGR, and the highest ER value always occurred at FA 90°. The FA for the highest ER differed from that for the highest signal-to-noise or contrast-to-noise ratio. For long TR, the ER value increases gradually. However, for short TR, the ER value increases rapidly and plateaus so that the ER value changes little beyond a certain FA value. Therefore, we suggest use of a higher FA, near 90°, to obtain a higher ERmax for long TR in 2D SPGR or FSPGR and a smaller FA, much less than 90°, to reach an appropriate ERmax for short TR in 3D SPGR or FSPGR. This information could be helpful in setting the optimal parameters for DCE-MRI.


Assuntos
Adenocarcinoma/patologia , Simulação por Computador , Aumento da Imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos , Animais , Meios de Contraste , Modelos Animais de Doenças , Imagens de Fantasmas , Coelhos , Coxa da Perna/patologia
15.
BMC Musculoskelet Disord ; 15: 36, 2014 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-24507771

RESUMO

BACKGROUND: Low-intensity pulsed ultrasound (LIPUS) regiment has been used to treat fractures with non-union and to promote bone union in general. The effect of LIPUS on articular cartilage metabolism has been characterized. Yet, the effect of LIPUS to repair articular cartilage injury remains unclear in vivo. METHODS: We designed a study to investigate the effect of LIPUS on articular cartilage repairing in a rabbit severe cartilage injury model. Eighteen rabbits were divided into three groups: Sham-operated group, operated group without-LIPUS-treatment, operated group with-LIPUS-treatment (a daily 20-minute treatment for 3 months). Full-thickness cartilage defects were surgically created on the right side distal femoral condyle without intending to penetrate into the subchondral bone, which mimicked severe chondral injury. MR images for experimental joints, morphology grading scale, and histopathological Mankin score were evaluated. RESULTS: The preliminary results showed that the operated groups with-LIPUS-treatment and without-LIPUS-treatment had significantly higher Mankin score and morphological grading scale compared with the sham-operated group. However, there was no significant difference between the with-LIPUS-treatment and without-LIPUS-treatment groups. Cartilage defects filled with proliferative tissue were observed in the with-LIPUS-treatment group grossly and under MR images, however which presented less up-take under Alcian blue stain. Furthermore, no new deposition of type II collagen or proliferation of chondrocyte was observed over the cartilage defect after LIPUS treatment. CONCLUSION: LIPUS has no significant therapeutic potential in treating severe articular cartilage injury in our animal study.


Assuntos
Doenças das Cartilagens/terapia , Cartilagem Articular , Condrogênese , Regeneração , Terapia por Ultrassom , Animais , Doenças das Cartilagens/patologia , Doenças das Cartilagens/fisiopatologia , Cartilagem Articular/patologia , Cartilagem Articular/fisiopatologia , Modelos Animais de Doenças , Feminino , Imageamento por Ressonância Magnética , Coelhos , Índice de Gravidade de Doença , Fatores de Tempo
16.
Artigo em Inglês | MEDLINE | ID: mdl-24109886

RESUMO

The incidence rate of capsular contracture after breast implant is about 8% to 12%. Patients would feel extremely uncomfortable after scar formation. Administering oral medications (such as vitamin E and Zafirlukast tablets, etc.) or invasive breast capsulectomy surgery was commonly used for capsular contracture repair in clinical therapy. However, the therapeutic effect is still under investigation. Shock waves can be used to remove soft connective tissue in clinical applications. It has been widely used in orthopedics and rehabilitation. No related research paper about shock wave treatment of capsular contracture has been published yet. It might provide another choice for capsular contracture repair. In order to simulate breast implantation, two silica-gel bags filled with normal saline were implanted into New Zealand rabbit's thighs bilaterally as an animal model. Six weeks later, daily shock wave treatment on the right thigh was performed for six weeks after capsular contractures were formed, while the other thigh was used as a control. Then, magnetic resonance imaging (MRI) was used to compare the difference between treated and un-treated thighs. Afterwards, pathological sections were analyzed to confirm the findings. It has been demonstrated that shock wave treatments are capable of changing the structure and composition of capsular contractures. The structure of scar became myxoid changed or collagen deposition of scar decreased after shock wave treatment, hence, the formation of scars decreased. Increased myxoid and decreased collagen deposition has also been found.


Assuntos
Implantes de Mama/efeitos adversos , Ondas de Choque de Alta Energia , Contratura Capsular em Implantes/terapia , Animais , Colágeno/metabolismo , Feminino , Imageamento por Ressonância Magnética , Glândulas Mamárias Animais/patologia , Modelos Animais , Coelhos
17.
ScientificWorldJournal ; 2012: 343847, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22778696

RESUMO

Most patients with liver cirrhosis must undergo a series of clinical examinations, including ultrasound imaging, liver biopsy, and blood tests. However, the quantification of liver cirrhosis by extracting significant features from a T2-weighted magnetic resonance image (MRI) provides useful diagnostic information in clinical tests. Sixty-two subjects were randomly selected to participate in this retrospective analysis with assigned to experimental and control groups. The T2-weighted MRI was obtained and to them dynamic adjusted gray levels. The extracted features of the image were standard deviation (SD), mean, and entropy of pixel intensity in the region of interest (ROI). The receiver operator characteristic (ROC) curve, 95% confidence intervals, and kappa statistics were used to test the significance and agreement. The analysis of area under ROC shows that SD, mean, and entropy in the ROI were significant between the experimental group and the control group. Smaller values of SD, mean, and entropy were associated with a higher probability of liver cirrhosis. The agreements between the extracted features and diagnostic results were shown significantly (P < 0.001). In this investigation, quantitative features of SD, mean, and entropy in the ROI were successfully computed by the dynamic gray level scaling of T2-weighted MRI with high accuracy.


Assuntos
Algoritmos , Interpretação de Imagem Assistida por Computador/métodos , Cirrose Hepática/patologia , Reconhecimento Automatizado de Padrão/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Opt Express ; 18(2): 645-55, 2010 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-20173884

RESUMO

A color-separation system that angularly positions color LEDs to produce color separation and a lens array to focus this light onto the pixels is proposed. The LED rays from different incident angles are mapped into corresponding sub-pixel positions to efficiently display color image, which can be used to replace the absorbing color filter in the conventional liquid crystal layer. In this paper, the prototype backlight has been designed, fabricated and characterized. The measurement results of this module showed that a gain factor of transmission efficiency three times more than that of conventional color filters efficiency improvement and a larger color gamut are expected.


Assuntos
Cor , Iluminação/instrumentação , Refratometria/instrumentação , Semicondutores , Processamento de Sinais Assistido por Computador/instrumentação , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Projetos Piloto , Espalhamento de Radiação
19.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 1650-1, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-17282525

RESUMO

[Gd(TTDA-BOM)]2-is a newly developed paramagnetic contrast agent.The ligand,TTDA-BOM,bears a benzyloxymethyl group so that the lipophilicity is increased. The water exchange rate for [Gd(TTDA-BOM)]2-is significantly higher than that of [Gd(DTPA)]2-and [Gd(BOPTA)]2-.In addition, the bound relaxivity of this Gd (III) complex has a remarkably high value with HSA. Therefore,it has potential to be used as a blood pool contrast agent for MRI. The aim of this study is to investigate the characterization and imaging behavior of NMG2[Gd(TTDA-BOM)] in normal rat livers and hearts using a 3T high field whole-body MR scanner.The high field MR scanner is expected to have a higher signal to noise ratio. The relaxivities r1and r2for [Gd(TTDA-BOM)]2-at 3T are 5.97 mM-1s-1and 7.99 mM-1s-1respectively, which are higher than those for [Gd(DTPA)]2(r1=4.64 mM-1s-1and r2= 5.08 mM-1s-1). The dynamic MRI studies show that there is marked enhancement in livers and hearts right after the bolus injection and the enhancement ratios keep high until two hours. In conclusion, [Gd(TTDA-BOM)]2-might have a good potential in both cardiovascular and hepatobiliary applications.

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