Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Life Sci ; 270: 119033, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33497737

RESUMO

AIMS: Physical exercise is beneficial to the recovery of patients with ischemic stroke. However, the underlying mechanism by which exercise promotes dendritic remodeling and synaptic plasticity is still obscure. This study explored the mechanism by which treadmill exercise enhances synaptic plasticity and dendritic remodeling in the ischemic penumbra. MAIN METHODS: A middle cerebral artery occlusion (MCAO) model was generated in C57BL/6 mice, and lentivirus-mediated cytoplasmic FMRP-associated protein 1 (CYFIP1) shRNA expression was utilized to confirm the role of CYFIP1 in the exercise-induced increase in synaptic plasticity and dendritic remodeling. Neurological deficits were measured using the Zea Longa scale. Hematoxylin-eosin (H&E) staining and Nissl staining were performed to assess cerebral ischemic injury. Golgi-Cox staining was used to observe changes in dendritic remodeling and synaptic plasticity. Transmission electron microscopy (TEM) was performed to observe the synaptic ultrastructure. Molecular mechanisms were explored using immunofluorescence staining and western blotting. KEY FINDINGS: Treadmill training enhanced synaptic plasticity in the penumbra. Additionally, we observed significant increases in the expression of CYFIP1 and calcium/calmodulin-dependent kinase 2a (Camk2a); enhanced neurological recovery and a decreased infarct volume. However, the injection of a lentivirus containing CYFIP1 shRNA into the lateral ventricle exerted negative effects on synaptic plasticity. Moreover, the exercise-induced neuroprotective effects were abolished by lentivirus-mediated CYFIP1 shRNA expression, consistent with the downregulation of Camk2a expression and the deterioration of neurological function. SIGNIFICANCE: Treadmill training enhances synaptic plasticity and dendritic remodeling in the ischemic penumbra by inducing the expression of Camk2a via upregulation of CYFIP1.

2.
Behav Brain Res ; 401: 113085, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33358915

RESUMO

Rehabilitation training is routine for children who experience stroke, but its protective mechanism remains unclear. To study the effect of treadmill training intensity on hippocampal synaptic plasticity after cerebral ischemia, a model of middle cerebral artery occlusion (MCAO)/reperfusion was established in young rats to simulate childhood ischemic stroke. The rats were randomly allocated into five groups: sham operation, MCAO, low-intensity exercise and MCAO (5 m/min), medium-intensity exercise and MCAO (10 m/min), and high-intensity exercise and MCAO (15 m/min). Intervention was continued for 14 days, and a series of experimental tests were conducted. After MCAO, the juvenile rats exhibited a series of morphological and functional alterations, including changes in their neurobehavior and cerebral infarct volumes. Compared with control rats, MCAO rats had a longer escape latency and crossed fewer platforms in the water maze test and exhibited decreased hippocampal neuron density and Synapsin I and PSD95 expression. Furthermore, MCAO rats exhibited synapse morphology changes and abnormal serum levels of lactic acid and corticosterone. Treadmill training effectively reduced the neurobehavioral scores and cerebral infarction volumes, with medium-intensity training showing the best effect. Treadmill training shortened the escape latency, increased the number of platform crossings, and improved the spatial cognitive abilities of the rats, with the medium intensity training having the best effect on spatial learning/memory efficiency. Treadmill training increased the neuron density in the hippocampus, with the medium-intensity training resulting in the highest density. Treadmill training had a positive effect on the expression of Synapsin I and PSD95, with the medium-intensity training showing the strongest effect. Treadmill training improved the sub-microstructure synapse morphology, with the medium-intensity training demonstrating the best effect. Treadmill training increased the plasma levels of lactic acid and corticosterone, with the high-intensity training having the most obvious effect. Treadmill training can provide neuroprotection by promoting hippocampal synaptic plasticity, with medium-intensity training showing the most optimal effects.

3.
Urol Oncol ; 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33268274

RESUMO

OBJECTIVE: Financial toxicity (FT) has been defined as the patient-level impact of the costs of cancer care. Our objective was to better characterize FT among bladder cancer patients as well as oncologic, demographic and insurance characteristics related to FT. METHODS: We conducted a cross-sectional survey of the Bladder Cancer Advocacy Network Patient Survey Network using the validated COST (COmprehensive Score for financial Toxicity) questionnaire. Our primary outcome was relative degree of FT, with lower COST scores corresponding to worse FT. Wilcoxon rank sum tests and multiple regression were used to evaluate differences in demographic, diagnostic and treatment characteristics as they related to degree of FT. RESULTS: Among 226 patients, median age was 68 years with 64% male, 83% married, and 49% with Medicare with supplemental insurance. Respondents reported an average of 65 months since diagnosis, with 62% reporting noninvasive disease. Mean COST was 28.4 (range 0-44). On multivariable analysis, patients who were younger, with a household annual income less than $50,000, not retired, or with insurance that was neither Medicare nor employer paid were significantly more likely to have worse FT. A majority of respondents (63.5%) agreed or strongly agreed that they would be interested in discussing cost in the context of their treatment preferences, independent of COST score (P = 0.24). CONCLUSIONS: A national cross-sectional survey demonstrated high prevalence of FT which was worse among younger patients with lower incomes, not retired, and without employer-paid or Medicare insurance. Most patients preferred to discuss treatment costs with their bladder cancer provider.

4.
Life Sci ; : 118634, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33148419

RESUMO

AIMS: Exercise training has a neuroprotective effect against ischaemic injury, but the underlying mechanism is not completely clear. This study explored the potential mechanisms underlying the protective effects of treadmill training and caveolin-1 regulation against mitochondrial dysfunction in cerebral ischaemic injury. MAIN METHODS: After middle cerebral artery occlusion (MCAO) surgery, rats were subjected to treadmill training and received daidzein injections and combined therapy. A series of analyses, including neurological function scoring; body weight measurement; Nissl, haematoxylin and eosin staining; cerebral infarction volume assessment; mitochondrial morphology examination; caveolin-1, cytoplasmic and mitochondrial cytochrome C (CytC), and translocase of outer membrane 20 (TOM20) expression analysis; apoptosis index analysis; and transmission electron microscopy were conducted. KEY FINDINGS: Treadmill training increased caveolin-1 expression, reduced neurobehavioral scores and cerebral infarction volumes, improved tissue morphology, reduced neuronal loss, inhibited mitochondrial outer membrane permeabilization (MOMP) through the caveolin-1 pathway, prevented excessive Cyt-C release from mitochondria, and reduced the degrees of apoptosis and mitochondrial damage. In addition, treadmill training increased the expression of TOM20 through the caveolin-1 pathway and maintained import signal function, thereby protecting mitochondrial integrity. SIGNIFICANCE: Treadmill exercise protected mitochondrial integrity and inhibited the endogenous mitochondrial apoptosis pathway. The damage of cerebral ischaemia was alleviated in rats through enhancement of caveolin-1 by treadmill exercise.

5.
Ultrasound Med Biol ; 46(12): 3188-3199, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32896449

RESUMO

The purpose of this study was to develop, validate and test a prediction model for discriminating malignant from benign breast lesions using conventional ultrasound (US), US elastography of strain elastography and contrast-enhanced ultrasound (CEUS). The study included 454 patients with breast imaging-reporting and data system (BI-RADS) category 4 breast lesions identified on histologic examinations. Firstly, 228 breast lesions (cohort 1) were analyzed by logistic regression analysis to identify the risk factors, and a breast malignancy prediction model was created. Secondly, the prediction model was validated in cohort 2 (84 patients) and tested in cohort 3 (142 patients) by using analysis of the area under the receiver operating characteristic curve (AUC). Univariate regression indicated that age ≥40 y, taller than wide shape on US, early hyperenhancement on CEUS and enlargement of enhancement area on CEUS were independent risk factors for breast malignancy (all p < 0.05). The logistic regression equation was established as follows: p = 1/1+Exp∑[-5.066 + 3.125 x (if age ≥40 y) + 1.943 x (if taller than wide shape) + 1.479 x (if early hyperenhancement) + 4.167 x (if enlargement of enhancement area). The prediction model showed good discrimination performance with an AUC of 0.967 in cohort 1, 0.948 in cohort 2 and 0.920 in cohort 3. By using the prediction model to selectively downgrade category 4a lesions, the re-rated BI-RADS yield an AUC of 0.880 (95% confidence interval [CI], 0.794-0.965) in cohort 2 and 0.870 (95% CI, 0.801-0.939) in cohort 3. The specificity increased from 0.0% (0/35) to 80.0% (28/35) without loss of sensitivity (from 100.0% to 95.9%, p = 0.153) in cohort 2. Similarly, the specificity increased from 0.0% (0/58) to 77.6% (45/58) without loss of sensitivity (from 100.0% to 96.4%, p = 0.081) in cohort 3. Multimodal US showed good diagnostic performance in predicting breast malignancy of BI-RADS category 4 lesions. Although the loss of sensitivity was existing, the addition of multimodal US to US BI-RADS could improve the specificity in BI-RADS category 4 lesions, which reduced unnecessary biopsies.

6.
Biochem Pharmacol ; 180: 114116, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32579960

RESUMO

Runt-related transcription factor 1 (RUNX1), one subunit of core-binding factors in hematopoiesis and leukemia, was highly expressed in ovarian cancer (OC), but the role of RUNX1 in OC is largely unknown. Since we found that high expression of RUNX1 is correlated with poor survival in patients with OC through bioinformatic analysis of TCGA database, we developed RUNX1-knockout clones by CRISPR/Cas9 technique and discovered that RUNX1 depletion could promote cisplatin-induced apoptosis in OC cells, which was further confirmed by RUNX1 knockdown and overexpression. We also proved that RUNX1 could elevate the expression of BCL2. We then examined a total of 32 candidate miRNAs that might mediate the regulation between RUNX1 and BCL2, of which three miRNAs from the miR-17~92 cluster were found to be negatively regulated by RUNX1. Consistently, our analysis of data from TCGA database revealed the negative correlation between RUNX1 and the cluster. We further confirmed that miR-17~92 cluster could enhance cisplatin-induced apoptosis by directly targeting BCL2 3'UTR. Since rescue experiments proved that RUNX1 could repress cisplatin-induced apoptosis by up-regulating BCL2 via miR-17~92 cluster, combining RUNX1 inhibitor Ro5-3335 and cisplatin showed synergic effect in triggering OC cell apoptosis. Collectively, these findings show for the first time that combinational treatment of cisplatin and RUNX1 inhibitor could be used to potentiate apoptosis of ovarian cancer cells, and reveal the potential of targeting RUNX1 in ovarian cancer chemotherapy.

7.
J Ultrasound Med ; 39(10): 2059-2070, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32367518

RESUMO

OBJECTIVES: The purpose of this study was to establish a scoring system for predicting axillary lymph node metastasis (ALNM) in patients with breast invasive ductal carcinoma with negative axillary ultrasound (US) results. METHODS: In this retrospective study, 156 breast invasive ductal carcinoma lesions from 156 women were retrospectively enrolled. The features of conventional US and contrast-enhanced ultrasound (CEUS) qualitative enhancement patterns and quantitative enhancement parameters were analyzed. Subsequently, a scoring system was created by a multivariate logistic regression analysis. RESULTS: The results found that 60 patients (38%) showed ALNM. A scoring system was defined as risk score = 1.75 × (if lesion size ≥20 mm) + 1.93 × (if uncircumscribed margin shown on conventional US) + 1.77 × (if coarse or twisting penetrating vessels shown on CEUS). When the risk scores were less than 1.75, 1.75 to 1.93, 1.94 to 3.70, and 3.70 or higher, the risk rates of ALNM were 0% (0 of 9), 10.7% (5 of 46), 29.2% (14 of 48) and 77.4% (41 of 53), respectively. In comparison with conventional US alone, the scoring system using the combination of conventional US and CEUS showed better discrimination ability in terms of the area under the curve (0.830 versus 0.777; P = .037). CONCLUSIONS: A scoring system based on conventional US and CEUS may improve the prediction of ALNM.

9.
Stat Med ; 39(10): 1458-1472, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32101641

RESUMO

Pharmacoinformatics research has experienced a great deal of successes in detecting drug-induced adverse events (AEs) using large-scale health record databases. In the era of polypharmacy, pharmacoinformatics faces many new challenges, and two significant challenges are to detect high-order drug interactions and to handle strongly correlated drugs. In this article, we propose a super-combo-drug test (SupCD-T) to address the aforementioned two challenges. SupCD-T detects drug interactions by identifying optimal drug combinations with increased AE risks. In addition, SupCD-T increases the statistical powers to detect single-drug effects by combining strongly correlated drugs. Although SupCD-T does not distinguish single-drug effects from their combination effects, it is noticeably more powerful in selecting an individual drug effect in the multiple regression analysis, where confounding justification between two correlated drugs reduces the power in testing the individual drug effects on AEs. Our simulation studies demonstrate that SupCD-T has generally better power comparing with the multiple regression analysis. In addition, SupCD-T is able to select meaningful drug combinations (eg, highly coprescribed drugs). Using electronic health record database, we illustrate the utility of SupCD-T and discover a number of drug combinations that have increased risk in myopathy. Some novel drug combinations have not yet been investigated and reported in the pharmacology research.

11.
Nucleic Acids Res ; 47(18): e105, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31372651

RESUMO

A primary challenge in the analysis of RNA-seq data is to identify differentially expressed genes or transcripts while controlling for technical biases. Ideally, a statistical testing procedure should incorporate the inherent uncertainty of the abundance estimates arising from the quantification step. Most popular methods for RNA-seq differential expression analysis fit a parametric model to the counts for each gene or transcript, and a subset of methods can incorporate uncertainty. Previous work has shown that nonparametric models for RNA-seq differential expression may have better control of the false discovery rate, and adapt well to new data types without requiring reformulation of a parametric model. Existing nonparametric models do not take into account inferential uncertainty, leading to an inflated false discovery rate, in particular at the transcript level. We propose a nonparametric model for differential expression analysis using inferential replicate counts, extending the existing SAMseq method to account for inferential uncertainty. We compare our method, Swish, with popular differential expression analysis methods. Swish has improved control of the false discovery rate, in particular for transcripts with high inferential uncertainty. We apply Swish to a single-cell RNA-seq dataset, assessing differential expression between sub-populations of cells, and compare its performance to the Wilcoxon test.


Assuntos
Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Algoritmos , Linhagem da Célula/genética , Expressão Gênica/genética , Humanos , RNA/genética , Software
12.
Theor Appl Genet ; 132(11): 3101-3114, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31432199

RESUMO

KEY MESSAGE: In the soybean cultivar Raiden, both a SMV-resistance gene and a BCMV-resistance gene were fine-mapped to a common region within the Rsv1 complex locus on chromosome 13, in which two CC-NBS-LRR resistance genes (Glyma.13g184800 and Glyma.13g184900) exhibited significant divergence between resistant and susceptible cultivars and were subjected to positive selection. Both Soybean mosaic virus (SMV) and Bean common mosaic virus (BCMV) can induce soybean mosaic diseases. To date, few studies have explored soybean resistance against these two viruses simultaneously. In this work, Raiden, a cultivar resistant to both SMV and BCMV, was crossed with a susceptible cultivar, Williams 82, to fine-map the resistance genes. After inoculating ~ 200 F2 individuals with either SMV (SC6-N) or BCMV (HZZB011), a segregation ratio of 3 resistant:1 susceptible was observed, indicating that for either virus, a single dominant gene confers resistance. Bulk segregation analysis (BSA) revealed that the BCMV-resistance gene is also linked to the SMV-resistance Rsv1 complex locus. Genotyping the F2 individuals with 12 simple sequence repeat (SSR) markers across the Rsv1 complex locus then preliminarily mapped the SMV-resistance gene, Rsv1-r, between SSR markers BARCSOYSSR_13_1075 and BARCSOYSSR_13_1161 and the BCMV-resistance gene between BARCSOYSSR_13_1084 and BARCSOYSSR_13_1115. Furthermore, a population of 1009 F2 individuals was screened with markers BARCSOYSSR_13_1075 and BARCSOYSSR_13_1161, and 32 recombinant F2 individuals were identified. By determining the genotypes of these F2 individuals on multiple internal SSR and single nucleotide polymorphism (SNP) markers and assaying the phenotypes of selected recombinant F2:3 lines, both the SMV- and BCMV-resistance genes were fine-mapped to a common region ( ~ 154.5 kb) between two SNP markers: SNP-38 and SNP-50. Within the mapped region, two CC-NBS-LRR genes exhibited significant divergence between Raiden and Williams 82, and their evolution has been affected by positive selection.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Potyvirus/patogenicidade , Soja/genética , Mapeamento Cromossômico , Genes Dominantes , Genes de Plantas , Marcadores Genéticos , Genótipo , Repetições de Microssatélites , Doenças das Plantas/virologia , Polimorfismo de Nucleotídeo Único , Seleção Genética , Soja/virologia
14.
Stat Methods Med Res ; 28(7): 2165-2178, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-29355073

RESUMO

One important goal in pharmaco-epidemiology studies is to understand the causal relationship between drug exposures and their clinical outcomes, including adverse drug events. In order to achieve this goal, however, we need to resolve several challenges. Most of pharmaco-epidemiology data are observational and confounding is largely present due to many co-medications. The pharmaco-epidemiology study data set is often sampled from large medical record databases using a matched case-control design, and it may not be representative of the original patient population in the medical record databases. Data analysis method needs to handle a large sample size that cannot be handled using existing statistical analysis packages. In this paper, we tackle these challenges both methodologically and computationally. We propose a conditional causal log-odds ratio (OR) definition to characterize causal effects of drug exposures on a binary adverse drug event adjusting for individual level confounders. Using a case-control design, we present a propensity score estimation using only case samples and we provide sufficient conditions for the consistency of the estimation of the causal log-odds ratio using case-based propensity scores. Computationally, we implement a principle component analysis to reduce high-dimensional confounders. Extensive simulation studies are performed to demonstrate superior performance of our method to existing methods. Finally, we apply the proposed method to analyze drug-induced myopathy data sampled from a de-identified subset of medical record database (close to 5 million patient records), The Indiana Network for Patient Care. Our method identified 70 drug-induced myopathy (p < 0.05) out 72 drugs, which have myoathy side effects on their FDA drug labels. These 70 drugs include three statins who are known for their myopathy side effects.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Estudos Epidemiológicos , Estudos de Casos e Controles , Causalidade , Bases de Dados Factuais , Humanos , Registros Médicos , Razão de Chances , Medicamentos sob Prescrição/efeitos adversos , Pontuação de Propensão
15.
Bioinformatics ; 35(12): 2084-2092, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30395178

RESUMO

MOTIVATION: In RNA-seq differential expression analysis, investigators aim to detect those genes with changes in expression level across conditions, despite technical and biological variability in the observations. A common task is to accurately estimate the effect size, often in terms of a logarithmic fold change (LFC). RESULTS: When the read counts are low or highly variable, the maximum likelihood estimates for the LFCs has high variance, leading to large estimates not representative of true differences, and poor ranking of genes by effect size. One approach is to introduce filtering thresholds and pseudocounts to exclude or moderate estimated LFCs. Filtering may result in a loss of genes from the analysis with true differences in expression, while pseudocounts provide a limited solution that must be adapted per dataset. Here, we propose the use of a heavy-tailed Cauchy prior distribution for effect sizes, which avoids the use of filter thresholds or pseudocounts. The proposed method, Approximate Posterior Estimation for generalized linear model, apeglm, has lower bias than previously proposed shrinkage estimators, while still reducing variance for those genes with little information for statistical inference. AVAILABILITY AND IMPLEMENTATION: The apeglm package is available as an R/Bioconductor package at https://bioconductor.org/packages/apeglm, and the methods can be called from within the DESeq2 software. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Software , Funções Verossimilhança , Modelos Lineares , Análise de Sequência de RNA
16.
Sensors (Basel) ; 18(9)2018 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-30205607

RESUMO

The body dimension measurement of large animals plays a significant role in quality improvement and genetic breeding, and the non-contact measurements by computer vision-based remote sensing could represent great progress in the case of dangerous stress responses and time-costing manual measurements. This paper presents a novel approach for three-dimensional digital modeling of live adult Qinchuan cattle for body size measurement. On the basis of capturing the original point data series of live cattle by a Light Detection and Ranging (LiDAR) sensor, the conditional, statistical outliers and voxel grid filtering methods are fused to cancel the background and outliers. After the segmentation of K-means clustering extraction and the RANdom SAmple Consensus (RANSAC) algorithm, the Fast Point Feature Histogram (FPFH) is put forward to get the cattle data automatically. The cattle surface is reconstructed to get the 3D cattle model using fast Iterative Closest Point (ICP) matching with Bi-directional Random K-D Trees and a Greedy Projection Triangulation (GPT) reconstruction method by which the feature points of cattle silhouettes could be clicked and calculated. Finally, the five body parameters (withers height, chest depth, back height, body length, and waist height) are measured in the field and verified within an accuracy of 2 mm and an error close to 2%. The experimental results show that this approach could be considered as a new feasible method towards the non-contact body measurement for large physique livestock.


Assuntos
Algoritmos , Tamanho Corporal , Bovinos/anatomia & histologia , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Animais , Bovinos/classificação , Bovinos/genética , Masculino
17.
Theor Appl Genet ; 131(9): 1851-1860, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29909526

RESUMO

KEY MESSAGE: In the soybean cultivar Suweon 97, BCMV-resistance gene was fine-mapped to a 58.1-kb region co-localizing with the Soybean mosaic virus (SMV)-resistance gene, Rsv1-h raising a possibility that the same gene is utilized against both viral pathogens. Certain soybean cultivars exhibit resistance against soybean mosaic virus (SMV) or bean common mosaic virus (BCMV). Although several SMV-resistance loci have been reported, the understanding of the mechanism underlying BCMV resistance in soybean is limited. Here, by crossing a resistant cultivar Suweon 97 with a susceptible cultivar Williams 82 and inoculating 220 F2 individuals with a BCMV strain (HZZB011), we observed a 3:1 (resistant/susceptible) segregation ratio, suggesting that Suweon 97 possesses a single dominant resistance gene against BCMV. By performing bulked segregant analysis with 186 polymorphic simple sequence repeat (SSR) markers across the genome, the resistance gene was determined to be linked with marker BARSOYSSR_13_1109. Examining the genotypes of nearby SSR markers on all 220 F2 individuals then narrowed down the gene between markers BARSOYSSR_13_1109 and BARSOYSSR_13_1122. Furthermore, 14 previously established F2:3 lines showing crossovers between the two markers were assayed for their phenotypes upon BCMV inoculation. By developing six more SNP (single nucleotide polymorphism) markers, the resistance gene was finally delimited to a 58.1-kb interval flanked by BARSOYSSR_13_1114 and SNP-49. Five genes were annotated in this interval of the Williams 82 genome, including a characteristic coiled-coil nucleotide-binding site-leucine-rich repeat (CC-NBS-LRR, CNL)-type of resistance gene, Glyma13g184800. Coincidentally, the SMV-resistance allele Rsv1-h was previously mapped to almost the same region, thereby suggesting that soybean Suweon 97 likely relies on the same CNL-type R gene to resist both viral pathogens.


Assuntos
Resistência à Doença/genética , Genes de Plantas , Doenças das Plantas/genética , Potyvirus , Soja/genética , Mapeamento Cromossômico , Genes Dominantes , Marcadores Genéticos , Repetições de Microssatélites , Doenças das Plantas/virologia , Polimorfismo de Nucleotídeo Único , Soja/virologia
18.
ACS Appl Mater Interfaces ; 7(39): 21668-72, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26402568

RESUMO

We report emulsion studies using poly(vinylphenyl boronic acid) (PVPBA) linear homopolymer as an effective emulsifier and gelator. Two stabilizing regimes were identified depending on the pH of PVPBA aqueous solutions, i.e., emulsions stabilized by the hompolymer nanoparticles (Pickering emulsions) at pH < pKa and emulsions stabilized by the homopolymer unimers at pH > pKa. In both cases, gelled emulsions were obtained from medium to high internal phase volume fractions with the unimers exhibiting more effective emulsification and gelling properties. Hydrogen bonding between the boronic acid units is proposed to account for the high strength of the emulsions. The emulsions were shown to be pH- and sugar-responsive. Finally, the stable emulsions were used as templates to directly prepare PVPBA macroporous materials and to fabricate multilayered capsules. This remarkable observation that a simple homopolymer can serve as an effective emulsifier and gelator may dramatically extend the scope of potential emulsifiers and inspire further research in the design of new types of efficient emulsifying agents.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA