Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Helminthol ; 98: e41, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38785193

RESUMO

Background: Inflammatory bowel disease is an autoimmune disease that affects the gut. T. spiralis larvae (E/S Ags) loaded on calcium-benzene-1,3,5-tricarboxylate metal-organic frameworks (Ca-BTC MOFs) were tested to determine whether they might prevent or cure acetic acid-induced murine colitis. Methods: T. spiralis larvae E/S Ags/Ca-BTC MOFs were used in prophylactic and therapeutic groups to either precede or follow the development of murine colitis. On the seventh day after colitis, mice were slaughtered. The effect of our target antigens on the progress of the colitis was evaluated using a variety of measures, including survival rate, disease activity index, colon weight/bodyweight, colon weight/length) ratios, and ratings for macroscopic and microscopic colon damage. The levels of inflammatory cytokines (interferon-γ and interleukin-4), oxidative stress marker malondialdehyde, and glutathione peroxidase in serum samples were evaluated. Foxp3 T-reg expression was carried out in colonic and splenic tissues. Results: T. spiralis larvae E/S Ags/Ca-BTC MOFs were the most effective in alleviating severe inflammation in murine colitis. The survival rate, disease activity index score, colon weight/length and colon weight/bodyweight ratios, and gross and microscopic colon damage scores have all considerably improved. A large decrease in proinflammatory cytokine (interferon-γ) and oxidative stress marker (malondialdehyde) expression and a significant increase in interleukin-4 and glutathione peroxidase expression were obtained. The expression of Foxp3+ Treg cells was elevated in colonic and splenic tissues. Conclusion: T. spiralis larvae E/S Ags/Ca-BTC MOFs had the highest anti-inflammatory, antioxidant, and cytoprotective capabilities against murine colitis and might be used to develop new preventative and treatment strategies.


Assuntos
Colite , Citocinas , Larva , Estruturas Metalorgânicas , Trichinella spiralis , Animais , Camundongos , Estruturas Metalorgânicas/química , Colite/prevenção & controle , Colite/induzido quimicamente , Colite/parasitologia , Trichinella spiralis/imunologia , Antígenos de Helmintos/imunologia , Modelos Animais de Doenças , Colo/parasitologia , Colo/patologia , Camundongos Endogâmicos BALB C , Feminino , Masculino
2.
Sci Rep ; 13(1): 1570, 2023 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-36709332

RESUMO

Various vision-threatening eye diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR) are caused due to the dysfunctions manifested in the highly vascular choroid layer of the posterior segment of the eye. In the current clinical practice, screening choroidal structural changes is widely based on optical coherence tomography (OCT) images. Accordingly, to assist clinicians, several automated choroidal biomarker detection methods using OCT images are developed. However, the performance of these algorithms is largely constrained by the quality of the OCT scan. Consequently, determining the quality of choroidal features in OCT scans is significant in building standardized quantification tools and hence constitutes our main objective. This study includes a dataset of 1593 good and 2581 bad quality Spectralis OCT images graded by an expert. Noting the efficacy of deep-learning (DL) in medical image analysis, we propose to train three state-of-the-art DL models: ResNet18, EfficientNet-B0 and EfficientNet-B3 to detect the quality of OCT images. The choice of these models was inspired by their ability to preserve the salient features across all the layers without information loss. To evaluate the attention of DL models on the choroid, we introduced color transparency maps (CTMs) based on GradCAM explanations. Further, we proposed two subjective grading scores: overall choroid coverage (OCC) and choroid coverage in the visible region(CCVR) based on CTMs to objectively correlate visual explanations vis-à-vis DL model attentions. We observed that the average accuracy and F-scores for the three DL models are greater than 96%. Further, the OCC and CCVR scores achieved for the three DL models under consideration substantiate that they mostly focus on the choroid layer in making the decision. In particular, of the three DL models, EfficientNet-B3 is in close agreement with the clinician's inference. The proposed DL-based framework demonstrated high detection accuracy as well as attention on the choroid layer, where EfficientNet-B3 reported superior performance. Our work assumes significance in bench-marking the automated choroid biomarker detection tools and facilitating high-throughput screening. Further, the methods proposed in this work can be adopted for evaluating the attention of DL-based approaches developed for other region-specific quality assessment tasks.


Assuntos
Doenças da Coroide , Aprendizado Profundo , Humanos , Corioide/diagnóstico por imagem , Corioide/irrigação sanguínea , Doenças da Coroide/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos
3.
Comput Med Imaging Graph ; 99: 102086, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35717830

RESUMO

BACKGROUND AND OBJECTIVE: The choroid, a dense vascular structure in the posterior segment of the eye, maintains the health of the retina by supplying oxygen and nutrients, and assumes clinical significance in screening ocular diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR). As a technological assist, algorithmic estimation of choroidal biomarkers has been suggested based on sectional (B-scan) optical coherence tomography (OCT) images. However, most such 2D estimation techniques are compute-intensive, yet enjoy limited accuracy and have only been validated on OCT image datasets of healthy eyes. Not surprisingly, fine-scale analyses, including those involving Haller's sublayer, remain relatively rare and unsophisticated. Against this backdrop, we propose an efficient algorithm to quantify desired biomarkers with improved accuracy based on volume OCT scans. Specifically, we attempted an accurate, computationally light volumetric segmentation method involving stratified smoothing to detect choroid and Haller's sublayer. METHODS: For detecting the various boundaries of the choroid and the Haller's sublayer, we propose a common volumetric method that performs suitable exponential enhancement and maintains smooth spatial continuity across 2D B-scans. Further, we achieve suitable volumetric smoothing by primarily deploying light-duty linear regression, and sparingly using compute-intensive tensor voting, and hence significantly reduce overall complexity. The proposed methodology is tested on five health and five diseased OCT volumes considering various metrics including volumetric Dice coefficient and corresponding quotient measures to facilitate comparison vis-à-vis intra-observer repeatability. RESULTS: On five healthy and five diseased OCT volumes, respectively, the proposed method for choroid segmentation recorded volumetric Dice coefficients of 93.53 % and 93.30 %, which closely approximate the respective reference observer repeatability values of 95.60 % and 95.49 %. In terms of related quotient measures, our method achieved more than 50 % improvement over a recently reported method. In detecting Haller's sublayer as well, our algorithm records statistical performance closely matching that of reference manual method. CONCLUSION: Advancing the state-of-the-art, the proposed volumetric segmentation, tested on both healthy and diseased datasets, demonstrated close match with the manual reference. Our method assumes significance in accurate screening of chorioretinal diseases including AMD, CSCR and pachychoroid. Further, it enables generating accurate training data for developing deep learning models for improved detection of choroid and Haller's sublayer.


Assuntos
Degeneração Macular , Tomografia de Coerência Óptica , Algoritmos , Corioide/diagnóstico por imagem , Humanos , Degeneração Macular/diagnóstico por imagem , Retina/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 274: 121140, 2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35305518

RESUMO

In this work, a new chlorophyll dye-sensitiser derived from mitragyna speciosa (MS) leaves, also known as Kratom, was employed for dye-sensitised solar cells (DSSCs). The influence of magnesium sulfate (MgSO4), a low-cost dye additive, and suitable extraction solvents on the performance of DSSCs were examined. Here, the optical properties were investigated using UV-Visible spectroscopy and the functional anchoring group were investigated by FTIR spectroscopy. Meanwhile, the photovoltaic parameters were investigated by I-V measurements. The highest conversion efficiency is obtained when using a dye extracted from methanol solvent in combination with MgSO4 additive, namely methanolic magnesium sulfate (MMSO). This higher power conversion efficiency is mainly attributed to the enhancement of the hydroxyl group in the MMSO dye solutions, which promotes higher dye adsorption and provides an organic dye passivation layer that reduces back-recombination in the cell. Furthermore, MgSO4 aids in the replenishment of magnesium lost in the chlorophyll porphyrin ring during the degradation process. These combined effects have contributed to the overall conversion efficiency of the MMSO cell at 0.26 %, followed by 0.24 % for ethanolic magnesium sulfate (EMSO), respectively.


Assuntos
Corantes , Energia Solar , Clorofila/química , Corantes/química , Sulfato de Magnésio , Solventes/química , Luz Solar
5.
Sci Rep ; 11(1): 8732, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888821

RESUMO

To study the topographic distribution of the short posterior ciliary arteries (SPCA) entry sites into the choroid in normal eyes using structural en-face swept source optical coherence tomography (SS-OCT). Retrospective analysis of SS-OCT scans (wide-field structural SS-OCT 12 × 12 mm) of 13 healthy subjects was performed. Cross-sectional swept-source OCT scans derived from a volume scan were represented as en-face image display following the Choroid-Scleral Interface to obtain en-face OCT. SPCAs in their last scleral location before choroidal entrance were identified manually, counted and localized by two masked observers. Correlations between two masked observers were analyzed using inter- and intra-class correlation. Accuracy for the choroidal inner and outer border segmentation was 95-99%. Eighteen eyes from 13 normal subjects were included for SPCA analysis. The mean number of arteries was 13.8 ± 3.5 per eye. Thirty-six percent were in the center of the posterior pole image; however, 21% were in the temporal part of the posterior pole. Median accuracy of the detection is 0.94. The correlation between the two observers was fair (0.54). Our algorithm allows visualization of the SPCA at the posterior pole of the eye using wide-field en-face SS-OCT. It can also help the clinicians to study the SPCAs in numerous ocular diseases, particularly its relationship with focal choroidal diseases.


Assuntos
Corioide/irrigação sanguínea , Artérias Ciliares/anatomia & histologia , Esclera/irrigação sanguínea , Algoritmos , Estudos Transversais , Feminino , Humanos , Masculino , Estudos Retrospectivos , Tomografia de Coerência Óptica , Acuidade Visual
6.
Mater Sci Eng C Mater Biol Appl ; 102: 254-263, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146998

RESUMO

The aim of the current study was to biosynthesize the silver nanoparticles (AgNPs) from the bacterial strain of Bacillus cereus (ATCC 14579) extracellularly. When bacterial extract was challenged with 1 mM silver nitrate (AgNO3) the color of the extract changed into brown confirms the formation of nanoparticles. These nanoparticles were capped with bovine serum albumin (BSA). UV- visible spectroscopy showed the absorption peak at 420 nm indicates the formation of AgNPs. Fourier Infra -red (FTIR) attenuated total reflection (ATR) spectroscopy showed amide and amine group associated with AgNPs that stabilizes the nanoparticles. Energy dispersive x-ray spectroscopy (EDX) showed a strong peak of silver confirms the presence of silver. Thermo gravimetric analysis (TGA) analysis was used to determine the protein degradation showed less protein degradation at higher temperature confirms the stability of nanoparticles. Transmission electron microscopy (TEM) showed the AgNPs are well dispersed and spherical, and 5.37 nm to 17.19 whereas albumin coated nanoparticles are size ranges from 11.26 nm to 23.85 nm. The anticancer effect of capped AgNPs (cAgNPs) showed the IC50 value against breast cancer MCF-7 at 80 µg/mL, intestinal colon cancer HCT- 116 60 µg/mL, and bone cancer osteosarcoma MG-63 cell line80 µg/mL while against normal fibroblast cells 3T3 cells showed the IC50 value at 140 µg/mL. Lactate dehydrogenase assay (LDH) showed higher toxicity on MCF-7, HCT-116, and MG-63 cells. The apoptotic study clearly showed the blebbing of membrane, chromatin condensation due to the production of reactive oxygen species (ROS) by ethidium bromide and acridine orange dual staining method. The DNA analysis showed the complete fragmentation of the DNA of treated cells when compared with control cells.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose , Bioengenharia , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Soroalbumina Bovina/química , Prata/uso terapêutico , Células 3T3 , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Bovinos , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , DNA/metabolismo , Feminino , Nanopartículas Metálicas/ultraestrutura , Camundongos , Neoplasias/patologia , Prata/farmacologia , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
7.
J Diet Suppl ; 16(1): 66-85, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29469600

RESUMO

Moringa oleifera leaves were selected as a model due to their hundreds of health benefits. On the other hand, the powder of these leaves has exhibited poor flowability, low tensile strength, bitter taste, poor dissolution rate, and lack of information regarding dosage. These are the common hurdles and limitations in the adaptation of herbal-based medications. Therefore, a comprehensive study was planned to introduce herbal-based medicines into mainstream medicines by standardization according to the U.S. Food and Drug Administration (FDA) and international pharmaceutical standards. A Simplex Lattice Design (SLD) of Design Expert 8.0 software was used to formulate different concentrations of superdisintegrant, binder/diluent, and sweeteners. An Instron Universal Testing machine coupled with a 13 mm stainless cylindrical die was used to manufacture tablets by means of direct compression method at 20 kN applied force. Therefore, selection of excipients was made on the basis of their tensile strength, flowability, and taste-masking properties. Optimum formulation was tested on rabbits for toxicity and growth rate. All formulated tablets were evaluated on standard parameters for orally disintegrating tablets described by the Food and Drug Authority (U.S.). The optimum formulation fulfills all standard parameters such as hardness, disintegration time, friability, and dissolution rate. The present formulation showed no toxicity when tested on rabbits. The present study provides a fundamental understanding of the tableting characteristics of natural medicines. The present study provides information that will help to overcome the challenges.


Assuntos
Suplementos Nutricionais , Composição de Medicamentos/métodos , Moringa oleifera , Extratos Vegetais/administração & dosagem , Administração Oral , Animais , Química Farmacêutica , Excipientes , Feminino , Dureza , Folhas de Planta , Pós , Coelhos , Padrões de Referência , Software , Comprimidos , Paladar
8.
Appl Biochem Biotechnol ; 167(2): 314-26, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22544728

RESUMO

This paper investigates the degradation of polyhydroxyalkanoates and its biofiber composites in both soil and lake environment. Time-dependent changes in the weight loss of films were monitored. The rate of degradation of poly(3-hydroxybutyrate) [P(3HB)], poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-23 mol% 4HB)] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-9 mol% 3HV-co-19 mol% 4HB)] were investigated. The rate of degradation in the lake is higher compared to that in the soil. The highest rate of degradation in lake environment (15.6% w/w week(-1)) was observed with P(3HB-co-3HV-co-4HB) terpolymer. Additionally, the rate of degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-38 mol% 3HV)] was compared to PHBV biofiber composites containing compatibilizers and empty fruit bunch (EFB). Here, composites with 30% EFB displayed the highest rate of degradation both in the lake (25.6% w/w week(-1)) and soil (15.6% w/w week(-1)) environment.


Assuntos
Bactérias/metabolismo , Poluentes Ambientais/metabolismo , Óleos de Plantas/metabolismo , Poli-Hidroxialcanoatos/metabolismo , Bactérias/química , Biodegradação Ambiental , Cinética , Óleo de Palmeira , Óleos de Plantas/química , Poli-Hidroxialcanoatos/química
9.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 2): o522-3, 2011 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-21523172

RESUMO

The asymmetric unit of the title compound, C(58)H(96)N(2)O(4), contains two crystallographically independent mol-ecules. All cyclohexane rings are in chair conformations, while the furan ring is in an envelope conformation in one mol-ecule and a twist conformation in the other. Two acetaldehyde and one isobutane groups are disordered over two orientations with refined site occupancies of 0.940 (4):0.060 (4) and 0.791 (7):0.209 (7), respectively. In the crystal, mol-ecules are stacked along the a axis through van der Waals inter-actions.

10.
J Hazard Mater ; 182(1-3): 377-85, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20619537

RESUMO

The present study explores the ability of modified soda lignin (MSL) extracted from oil palm empty fruit bunches (EFB) in removing lead (II) ions from aqueous solutions. The effect of contact time, point zero charge (pH(pzc)) and pH of the solution, initial metal ion concentration and adsorbent dosage on the removal process were investigated. Furthermore, the MSL is characterized by SEM, XRF, FT-IR and surface area analysis. Equilibrium adsorption isotherms and kinetics were investigated. The experimental data were analyzed by the Langmuir, Freundlich and Temkin models of adsorption. The kinetic data obtained at different initial concentrations were analyzed using pseudo-first-order and pseudo-second-order models. The results provide strong evidence to support the hypothesis of adsorption mechanism.


Assuntos
Chumbo/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Modelos Teóricos , Tamanho da Partícula , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
12.
Trop Anim Health Prod ; 31(5): 307-19, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10509423

RESUMO

A survey on feeding practices was conducted with 60 farmers belonging to four categories (15 farmers in each): male farmers without off-farm income (M-), male farmers with off-farm income (M+), female farmers without off-farm income (W-), and female farmers with off-farm income (W+). Data on herd size, feeds offered, milk production, chest girth, reproduction and management were collected monthly over a period of 1 year. In addition, samples of fodder and concentrates were collected monthly and analysed for dry matter (DM), organic matter (OM), crude protein (CP) and in vitro organic matter digestibility (OMD). Of the 550 rations analysed, grass was included in 99.8% of all rations, followed by gliricidia (65%), creepers (50%) and jak leaves (32%). Consequently, the rations were high in OMD (47-59%) and CP (7.8-23.5%). High-protein forage or coconut cake or both were also included as a supplement in 92% of the rations. Both M- and W- farmers had larger (p < 0.001) herds (mean 1.8 animal units (AU) per household) than their counterparts with off-farm income (mean 1.44 AU/household), but only the male farmers without off-farm income achieved higher feeding levels (84.4 vs 65.6 72.1 g digestible organic matter (DOM)/kg0.75 per day) and milk production (6.4 vs 5.3-5.7 L/lactating cow). The lower production of animals kept by female and M+ farmers was related to lower feeding levels. M- farmers realized higher feeding levels than their M+ counterparts. W- farmers did not collect extra feed in response to higher levels of production. It was concluded that dairy farming in the mid-country of Sri Lanka is particularly important for poorer households without income from off-farm employment.


Assuntos
Agricultura , Ração Animal , Bovinos/fisiologia , Agricultura/economia , Agricultura/métodos , Criação de Animais Domésticos , Animais , Peso Corporal , Coleta de Dados , Feminino , Humanos , Lactação , Masculino , Leite/metabolismo , Valor Nutritivo , Estações do Ano , Fatores Sexuais , Sri Lanka
13.
Egypt Dent J ; 41(1): 1057-66, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9497641

RESUMO

160 specimens of composite (80 chemical and 80 light cured) were prepared in teflon mold 4 mm x 2.5 mm in dimension. Plaque samples were collected using absorbent paper points from 20 normal persons and 20 persons with cervical carious teeth. The samples were inoculated in TSB containing both types of composites. Duplicate cultures were done for aerobic and anaerobic incubations at 37 degrees C. There was no effect of both types of composite on the quality of the isolated organisms from normal group or patient group. Chemical and light cured composite increased significantly the count of aerobic bacterial plaque from normal group. While they decreased the count of aerobic bacterial plaque from patient group and also the anaerobic bacterial plaque from both normal and patient group.


Assuntos
Resinas Compostas/farmacologia , Placa Dentária/microbiologia , Adulto , Bactérias Aeróbias/efeitos dos fármacos , Bactérias Anaeróbias/efeitos dos fármacos , Técnicas Bacteriológicas , Contagem de Colônia Microbiana , Cárie Dentária/microbiologia , Feminino , Humanos , Técnicas In Vitro , Masculino
14.
J Egypt Soc Parasitol ; 21(3): 817-22, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1765695

RESUMO

Niclosamide, as a semisolid pharmaceutical form suitable for external use, was used in 4 different concentrations (0.5%, 1%, 2% & 4%) to paint albino mice tails at different periods before exposure to infection with S. mansoni cercariae. Complete protection (100%) was achieved in all mice painted on the same day, the previous day and 3 days before exposure to cercariae irrespective to the niclosamide concentrations. Neither eggs nor worms were detected. Also, no pathological changes were found in livers, spleens or intestines of those mice. On the other hand, no protection against infection was achieved in mice painted with, 0.5% or 1%, 7 days before exposure to cercariae. Partial protection (25% and 40%) was gained in mice painted with 2% or 4% concentration of the drug respectively. It can be concluded that locally application of niclosamide as an ointment can completely prevent the infection with S. mansoni for three days. So, testing the promising drug for human trials to evaluate its efficacy specially for those at high risk is recommended.


Assuntos
Niclosamida/uso terapêutico , Esquistossomose mansoni/prevenção & controle , Administração Tópica , Animais , Feminino , Camundongos , Niclosamida/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...