Processing and Characterization of Electrospun Nanofibers From Poly(lactic acid)/Trimethylchitosan Blends

Daniella Lury Morgado,Odilio Benedito Garrido Assis 한국고분자학회 2016 Macromolecular Research Vol.24 No.11

In this study the production of biodegradable nanofibrous structures of poly(lactic acid) (PLA) blended with the water-soluble salt trimethylchitosan (TMC) was investigated by using the electrospinning process. Different concentrations of PLA (8 and 10% w/v) and TMC (0.5, 1, and 2% w/v) were prepared and spun. The morphology, diameter and structure of PLA/TMC blended nanofibers were characterized by scanning electron microscope (SEM), atomic force microscope (AFM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and contact angle measurements. Images obtained from SEM showed that the blended nanofibers display a uniform and smooth morphology without bead formation. The diameters of the fibers were affected by the presence of chitosan derivative, decreasing from 264 to 184 nm when the TMC addition was 20% (w/w). FTIR and XRD results indicate strong intermolecular hydrogen bonds between the molecules of PLA and chitosan derivative, with reduction in the crystallinity, thermal stability and hydrophobicity as TMC content increases in the blend.

Alzheimer's Disease Diagnosis Using Misfolding Proteins in Blood

HeeYang Lee,Daniella Ugay,Seungpyo Hong,김영수 대한치매학회 2020 Dementia and Neurocognitive Disorders Vol.19 No.1

Alzheimer's disease (AD) is pathologically characterized by a long progressive phase of neuronal changes, including accumulation of extracellular amyloid-β (Aβ) and intracellular neurofibrillary tangles, before the onset of observable symptoms. Many efforts have been made to develop a blood-based diagnostic method for AD by incorporating Aβ and tau as plasma biomarkers. As blood tests have the advantages of being highly accessible and low cost, clinical implementation of AD blood tests would provide preventative screening to presymptomatic individuals, facilitating early identification of AD patients and, thus, treatment development in clinical research. However, the low concentration of AD biomarkers in the plasma has posed difficulties for accurate detection, hindering the development of a reliable blood test. In this review, we introduce three AD blood test technologies emerging in South Korea, which have distinctive methods of heightening detection sensitivity of specific plasma biomarkers. We discuss in detail the multimer detection system, the self-standard analysis of Aβ biomarkers quantified by interdigitated microelectrodes, and a biomarker ratio analysis comprising Aβ and tau.

Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers

Claudia Concha,María Daniella Carretta,Pablo Alarcón,Ivan Conejeros,Diego Gallardo,Alejandra Isabel Hidalgo,Nestor Tadich,Dante Daniel Cáceres,María Angélica Hidalgo,Rafael Agustín Burgos 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.2

Reactive oxygen species (ROS) production is one of the mainmechanisms used to kill microbes during innate immuneresponse. D-lactic acid, which is augmented during acuteruminal acidosis, reduces platelet activating factor(PAF)-induced ROS production and L-selectin shedding inbovine neutrophils in vitro. This study was conducted toinvestigate whether acute ruminal acidosis induced by acuteoligofructose overload in heifers interferes with ROSproduction and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugularvenipuncture, while ruminal samples were collected usingrumenocentesis. Lactic acid from plasma and ruminal sampleswas measured by HPLC. PAF-induced ROS production andL-selectin shedding were measured in vitro in bovineneutrophils by a luminol chemiluminescence assay and flowcytometry, respectively. A significant increase in ruminal andplasma lactic acid was recorded in these animals. Specifically,a decrease in PAF-induced ROS production was observed 8 hafter oligofructose overload, and this was sustained until 48 hpost oligofructose overload. A reduction in PAF-inducedL-selectin shedding was observed at 16 h and 32 h postoligofructose overload. Overall, the results indicated thatneutrophil PAF responses were altered in heifers with ruminalacidosis, suggesting a potential dysfunction of the innateimmune response.

Processing and Characterization of Chitosan Films with Incorporation of Ethanolic Extract from “Pequi” Peels

Caroline Alves Breda,Daniella Lury Morgado,Odílio Benedito Garrido Assis,Marta Cristina Teixeira Duarte 한국고분자학회 2017 Macromolecular Research Vol.25 No.11

Chitosan is a polysaccharide with excellent film forming ability widely evaluated as active packaging and edible coatings. Chitosan has good antimicrobial activity in gel form; however, in a solid state (film format), a reduction in this activity can occur due to spatial arrangement of the chains in the polymer matrix. Small amounts of natural compounds could then be added to the film formulations to improve both antifungal and antibacterial properties. One possible additive is the “pequi” (Caryocar brasiliense Comb.) peel ethanolic extract (PPE), which forms homogenous blend with chitosan and has proved antimicrobial activity. In this study the preparation of chitosan-PPE was evaluated concerning the effect promoted in the film structure due PPE incorporation. Films processed by casting were analyzed by Fourier transform infrared spectroscopy (FTIR), microscopy, X-ray diffraction, mechanical and thermal properties, water vapor permeability (WVP) and surface wettability. FTIR analysis indicates interactions between the phenolic compounds in the extract and the hydroxyl and amine groups present in the chitosan structure, by establishing a possible ester bonding between constituents. The presence of PPE resulted in a decrease of WVP and an increasing in hydrophobicity. The extract addition also reduced the film’s crystallinity along with a slight decrease of plasticity and lowering of the initial polymeric degradation temperature. However, the blend was characterized by a homogeneous matrix with smooth topography. The results suggest that PPE has good compatibility with chitosan, introducing small changes that do not alter the potential for medical or foodstuff applications.

Expression of gus and gfp Genes in Ggrlic (Allium sativum L.) Cells Following Particle Bombardment Transformation

Lacorte, Cristiano,Barros, Daniella The Korean Society of Plant Biotechnology 2000 Plant molecular biology and biotechnology research Vol.2 No.3

The activity of promoter sequences was evaluated in garlic cells using the $\beta$-glucuronidase (GUS) gene as a reporter. Histochemical GUS assay indicated transient GUS activity in leaf, callus and root cells 48 hours after particle bombardment transformation. Quantitative fluorometric assays in extracts of transformed leaves demonstrated that the CsVMV promoter induced the highest level of gene expression, which was, on average, ten fold the level induced by CaMV35S and by the Arabidopsis Act2 promoters and two fold the level expression observed with a construct containing a double CaMV35S plus the untranslated leader sequence from AMV. No activity or very low levels were observed when cells were transformed with plasmids rontaining the typical monocot promoters, Actl, from rice or the Ubi-1, from maize. The green fluorescent protein (GFP) was also tested as a marker gene for garlic transformation. Intense fluorescence was observed in leaf, callus and root cells transformed with a construct containing the gfp gene under control of the CaMV35 Promoter. No fluorescence was detected when the gfp was under control of the Ubi-1 promoter.

Cashew Gum-Chitosan Blended Films: Spectral, Mechanical and Surface Wetting Evaluations

Carla Silva Martins,Daniella Lury Morgado,Odilio Benedito Garrido Assis 한국고분자학회 2016 Macromolecular Research Vol.24 No.8

Blends of cashew tree gum with chitosan and glycerol as plasticizer were prepared by casting and characterized by Fourier transform infrared spectroscopy (FTIR), mechanical (DMA) and thermogravimetric analysis (TG), scanning electron microscopy (SEM) and surface wettability by static contact angle measurements. FTIR analysis confirmed the consolidation of both polysaccharides and revealed a clearly interaction between the glycerol molecules and hydroxyl groups of chitosan. Chitosan and glycerol improved films mechanical properties and interferes on surface wettability. The unblended cashew gum films presented hydrophilic surfaces (medium measure angle as 40o) and with the addition of chitosan provides a shift towards a more hydrophobic behavior (52o and 75o for additions of 0.5% and 1.0% (w/w) chitosan respectively). Microscopy surface observation confirmed that the presence of glycerol reduced film cracking, changing them from fragile to a more plastic property. The film forming ability of chitosan is also preserved when blending with cashew gum.

Feature recognition for graph-based assembly product representation using machine learning

Jonathan M. Worner,Daniella Brovkina,Oliver Riedel 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

The automation of the entire value chain of a product requires not only automated production and assembly, but also automated production and assembly planning. Today, assembly planning is mostly a manual task and is based on computer-aided design descriptions and technical drawings. For the automation of the assembly planning, an automated recognition of the assembly features of the goal product is essential. In this paper, a concept for an automatic recognition of form features as well as the assignment of the connections between them as joints to build the assembly feature is described. The feature recognition is based on point clouds and uses the PointNet architecture. A data set of point clouds for training and an approach for automatic recognition of shape and assembly features using a convolutional neural network is presented. This approach can be used to recognize 12 features and assign seven joints. The recognition rate for the form features is over 95%. Finally, the features and their connections are stored in a graph database.

Convalescent Plasma in Older Adults with COVID-19: A Systematic Review and Meta-Analysis

I Gusti Putu Suka Aryana,Dian Daniella,Ivana Beatrice Paulus,Sandra Surya Rini,Siti Setiati 대한노인병학회 2022 Annals of geriatric medicine and research Vol.26 No.3

Background: Among all patients infected with coronavirus disease 2019 (COVID-19), the older adult population was the most affected, with 80%–90% of fatalities occurring in this group. The effectiveness of convalescent plasma (CP) in older adults is considerably more restricted than that in adults, resulting in a demand for data on the efficacy of therapeutic CP in older adults. This meta-analysis of updated literature examined the effect of CP in older adults with COVID-19. Methods: Relevant literature was identified from studies indexed in the Cochrane, PubMed, and Google Scholar databases between December 2019 and April 2022. The primary outcome was all-cause mortality. Risk estimates were pooled using a random-effects model. The risk of bias was assessed by regression-based Egger test using the relative risk (RR) and upper and lower confidence intervals (CIs) of the three included studies. Results: Among 377 studies identified, three full-text studies that included 1,038 patients met the inclusion criteria. The results of our meta-analysis showed that CP administration lowered the mortality risk in older adults with COVID-19 (RR=0.47; 95% CI, 0.26–0.86; p=0.01; I2=0%, p<0.81). CP therapy was more useful if delivered early in the course of the disease (within 72 hours of onset) and in less severe stages of the disease. Mortality tended to be lower in the high-titer group. Conclusions: CP treatment was significantly associated with a lower risk of mortality in older adults with COVID-19 than in patients not administered CP. The timing of CP administration is critical since earlier treatment after disease onset was associated with a better prognosis.

Polyurethane Foam Reinforced with Fibers Pineaplle Crown Biocomposites for Sorption of Vegetable Oil

Isabella Loureiro Muller Costa,Francisco Maciel Monticeli,Daniella R. Mulinari 한국섬유공학회 2020 Fibers and polymers Vol.21 No.8

The concern in reducing the environmental impacts caused by human interference is increasing. Thus, theobjective of this study was to generate a sustainable solution for sorption of vegetable oil. It was developed and characterizedbiocomposites obtained from polyurethane derived from castor oil reinforced with fibers from the crown of pineapple forsorption of vegetable oil. The biocomposites were obtained by mass mixing the polyol with the prepolymer (1:1) andreinforced with 5 to 20 % (wt/wt) pineapple crown fiber in 18 and 35 mesh granulometry. The biocomposites and purepolyurethane were characterized by scanning electron microscopy (SEM), optical microscopy (OM), X-ray Diffraction(XRD), porosimetry, contact angle, and density. Sorption tests were carried out on the biocomposites and pure polyurethane(PU). The sorption capacity of the biocomposites was evaluated as a function of the fiber content inserted in the matrix. Results of the sorption tests showed that the biocomposites reinforced with fibers of 18 mesh (20 % wt) presentedapproximately twice the sorption capacity when compared to pure PU and others biocomposites results, due to high porositycombined with high surface area, which influenced directly in the oil sorption. Response surface methodology (RSM)tecnique confirmed the influence fibers granulometry and content on oil sorption.

Real-time distinct visualization of barotrauma risk monitored by electrical impedance tomography in a COVID-19 and latent tuberculosis case

Leite Wagner Souza,Campos Shirley Lima,Brandão Daniella Cunha,Morais Caio César Araújo,de Andrade Armèle Dornelas 대한중환자의학회 2022 Acute and Critical Care Vol.37 No.4