107 research outputs found

    Anthocyanins, Phenolics, and Antioxidant Capacity of Vaccinium L. in Texas, USA

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    Berries of Vaccinium spp. have long been an important source of food and pharmaceutical ingredients and are considered to have high antioxidant potential. Growing blueberries in Texas, United States is a substantial industry, but there is no report on their antioxidant capacity, total phenolics, and anthocyanins. This study evaluates antioxidant capacity and contents of total phenolics and anthocayanins in both fruits and leaves of 19 genotypes including five commercial cultivars and 11 selections of rabbiteye blueberry (V. ashei) and southern highbush (V. corymbosum hybrids), and three native species (V. darrowii, V. arboreum, and V. fuscatum) grown in Nacogdoches, Texas. Significant variations in antioxidant capacity (as measured by FRAP) and contents of total phenolics and anthocyanins in fruit were observed among different species, cultivars or selections with less variation observed among individual plants of the same genotype. Our data from rabbiteye blueberry selections and cultivars support the hypothesis that antioxidant capacity is more highly correlated to total phenolics than anthocyanins. The analysis of five species indicates that antioxidant activity decreased during ripening but total phenolics contents tended to increase with maturity. Antioxidant capacity, total phenolics, and anthocyanin content did not change significantly during storage at 4ºC or -20ºC for two weeks but decreased significantly when berries were oven dried at 65ºC for 48 h. Antioxidant capacity and total phenolics content in leaves of each genotype were 3 to 15 times higher than those in fruits

    Rational Reprogramming of Fungal Polyketide First Ring Cyclization

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    Resorcylic acid lactones (RAL) and dihydroxyphenylacetic acid lactones (DAL) represent important pharmacophores with heat shock response and immune system modulatory activities. The biosynthesis of these fungal polyketides involves a pair of collaborating iterative polyketide synthases (iPKSs): a highly reducing iPKS (hrPKS) whose product is further elaborated by a nonreducing iPKS (nrPKS) to yield a 1,3-benzenediol moiety bridged by a macrolactone. Biosynthesis of unreduced polyketides requires the sequestration and programmed cyclization of highly reactive poly-β-ketoacyl intermediates to channel these uncommitted, pluripotent substrates towards defined subsets of the polyketide structural space. Catalyzed by product template (PT) domains of the fungal nrPKSs and discrete aromatase/cyclase enzymes in bacteria, regiospecific first-ring aldol cyclizations result in characteristically different polyketide folding modes. However, a few fungal polyketides, including the DAL dehydrocurvularin, derive from a folding event that is analogous to the bacterial folding mode. The structural basis of such a drastic difference in the way a PT domain acts has not been investigated until now. We report here that the fungal versus the bacterial folding mode difference is portable upon creating hybrid enzymes, and structurally characterize the resulting unnatural products. Using structure-guided active site engineering, we unravel structural contributions to regiospecific aldol condensations, and show that reshaping the cyclization chamber of a PT domain by only three selected point mutations is sufficient to reprogram the dehydrocurvularin nrPKS to produce polyketides with a fungal fold. Such rational control of first ring cyclizations will facilitate efforts towards the engineered biosynthesis of novel chemical diversity from natural unreduced polyketides

    Involvement of endoplasmic reticulum stress in trigeminal ganglion corneal neuron injury in dry eye disease

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    Dry eye disease (DED) is a multifactorial disease with a high prevalence worldwide. Uncomfortable corneal sensations severely affect daily life in DED patients. Hence, corneal neuron injury is a vital pathogenesis in DED. Notably, endoplasmic reticulum stress (ERS) plays a role in peripheral neuron injury. However, the role of ERS in DED corneal neuron injury is still far from being clear. In this study, we established an environmental DED (eDED) model in vivo and a hyperosmotic DED model in vitro. Subsequently, trigeminal ganglion (TG) corneal neurons were retrograde labeled by WGA-Alexa Fluor 555, and fluorescence-activated cell sorting was used to collect targeted corneal neurons for RNA sequencing in mice. Our results revealed that there is TG corneal neuron injury but not neuron apoptosis in DED. ERS-related genes and proteins were upregulated in TG corneal neurons of the eDED mice. ERS inhibition alleviated TG corneal neuron’s ERS-related injury. Therefore, ERS-induced TG corneal neuron injury may be an important pathomechanism and provide a promising therapeutic approach to DED

    Femoral neck system vs. cannulated screws on treating femoral neck fracture: a meta-analysis and system review

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    ObjectiveThis meta-analysis aimed to compare the relative safety and efficacy of cannulated compression screw (CCS) and femoral neck system (FNS) in treating patients with femoral neck fractures and to provide evidence-based medical evidence for FNS in treating femoral neck fractures.MethodsPubMed, Embase, Cochrane, and China National Knowledge Infrastructure databases were searched to collect outcomes related to femoral neck fractures treated with FNS and CCS, including time to fracture healing, incidence of non-union, incidence of osteonecrosis of the femoral head, incidence of failure of internal fixation, rate of femoral neck shortening, Harris hip score, Barthel index, operative time, intraoperative blood loss, fluoroscopy frequency, and complications. A meta-analysis was performed using RevManv5.4 (The Cochrane Collaboration) and Stata v14.0 software.ResultsThis analysis included 21 studies involving 1,347 patients. The results showed that FNS was superior to CCS in terms of fracture healing time [mean difference (MD) = −0.75, 95% CI = (−1.04, −0.46), P < 0.05], incidence of bone non-union [odds ratio (OR) = 0.53, 95% CI = (0.29, 0.98), P = 0.04], incidence of osteonecrosis of the femoral head [OR = 0.49, 95% CI = (0.28, 0.86), P = 0.01], incidence of internal fixation failure [OR = 0.30, 95% CI = (0.18, 0.52), P < 0.05], rate of femoral neck shortening [OR = 0.38, 95% CI = (0.27, 0.54), P > 0.05], Harris hip score [MD = 3.31, 95% CI = (1.99, 4.63), P < 0.001], Barthel index [MD =  4.31, 95% CI = (3.02, 5.61), P < 0.05], intraoperative bleeding [MD = 14.72, 95% CI = (8.52, 20.92), P < 0.05], fluoroscopy frequency [OR = 0.53, 95% CI = (0.29, 0.98), P = 0.04], and complications [OR = 0.31, 95% CI = (0.22, 0.45), P < 0.05]. The difference between FNS and CCS in operative time was not statistically significant [MD = −2.41, 95% CI = (−6.88, 2.05), P = 0.29].ConclusionFNS treatment of femoral neck fracture can shorten the fracture healing time; reduce the incidence and translucent rate of bone non-union, osteonecrosis of the femoral head, and internal fixation failure; reduce intraoperative blood loss and postoperative complications; and improve hip joint function and activity. We are confident in the findings that FNS, an effective and safe procedure for internal fixation of femoral neck fractures, is superior to CCS

    Deep Learning Reservoir Parameter Prediction Based on Seismic Attribute Reduction: Take Ledong Area of Yinggehai Basin as an Example

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    As an important indicator to describe reservoir characteristics, reservoir modeling and fluid model, the accurate estimation of reservoir physical parameters can provide a powerful reference for reservoir prediction, but the traditional inversion method of reservoir physical parameters can not give consideration to inversion accuracy and spatial continuity. To solve the above problems, this paper introduced seismic attributes as input of deep learning algorithm. Aiming at the information redundancy among seismic attributes, random forest-recursive elimination method was used to reduce the seismic attributes, thus a prediction method of reservoir physical property parameters based on seismic attribute reduction was finally established. The actual data test results showed that the prediction results of reservoir physical parameters by deep learning based on seismic attribute reduction presented good accuracy and lateral resolution, which confirmed the effectiveness of the proposed method

    Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconus

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    Objective. To compare fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT (TD-OCT) in the determination of thinnest corneal thickness (TCT). Methods. This study included 55 keratoconus patients and 50 healthy volunteers. The RTVue-OCT (FD-OCT) and Visante-OCT (TD-OCT) were used for the measurement of the TCT. Three consecutive scans were performed. The comparison and agreement between the two modalities were analyzed by paired t-test, the Pearson correlation, intraclass correlation coefficient (ICC), and Bland-Altman plots. intraobserver repeatability was analyzed by the intraobserver within-subject standard deviation (S(w)), coefficient of variation (CV(w)), and ICC. Results. The TCT value of normal corneas was higher by RTVue-OCT (530.4 ± 19.7 μm) than Visante-OCT (521.5 ± 18.3 μm) (p<0.001). For keratoconus eyes, the TCT was 425.0 ± 58.2 μm and 424.4 ± 55.7 μm (difference being 0.6 ± 10.2 μm, p=0.604). Strong correlation (r = 0.938∼0.985) (ICC = 0.915–0.984) was observed between the two OCTs, and each OCT exhibited excellent repeatability in determining the TCT in all subjects (ICC = 0.984–0.994). Conclusions. The values of TCT obtained from RTVue-OCT and Visante-OCT were highly correlated; however, the two values were different. Both OCT instruments exhibited good intraobserver reliability. The existence of systematic differences suggested that the two instruments cannot be used interchangeably
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