143 research outputs found
Analyzing the performance of novel aerogel wound dressing
No full textLAUREA MAGISTRALECon la crescita della domanda di materiali nei campi biomedici, gli aerogel sono considerati nuovi materiali promettenti. L'aerogel di cellulosa è biocompatibile, altamente poroso e con proprietà meccaniche regolabili e ha il potenziale per essere utilizzato nelle applicazioni di medicazione delle ferite. D'altra parte, gli attuali aerogel hanno scarse proprietà meccaniche, una mancanza di metodi di elaborazione semplici e scalabili e procedure di fabbricazione difficili. In questo studio, una tecnica innovativa chiamata solution blow spinning (SBS) per la filatura di micro-/nano-fibre è stata combinata con l'essiccazione di anidride carbonica supercritica (scCO2) per lo sviluppo di tessuti non tessuti in aerogel di cellulosa (CAN) altamente porosi. L'agente bioattivo timolo è stato aggiunto alle fibre con essiccazione di scCO2 per avere materiale carico di farmaco. Inoltre, per la modifica della superficie viene utilizzata una reazione di esterificazione in fase gassosa.
In questo studio sono state sviluppate anche fibre singole con una tecnica di filatura a umido in cui la cellulosa è stata combinata con chitosano per aumentare le proprietà antibatteriche delle fibre.
Le fibre sono state prodotte durante questo progetto e analizzate in base ad analisi strutturali e morfologiche. Le immagini al microscopio elettronico a scansione (SEM) sono state in grado di mostrare la porosità nanoporosa intra e intermolecolare risultante. La biocompatibilità della fibra è stata determinata dal test XTT, che è stato in grado di mostrare le proprietà non tossiche delle fibre. Le proprietà di guarigione della ferita del materiale sono state confermate utilizzando un test di graffio cellulare. Allo stesso modo, sono stati eseguiti test XTT e cell scratch con timolo libero per esaminare l'interazione del timolo con le cellule in assenza di fibre. È stato studiato il test biassiale meccanico per le valutazioni meccaniche delle fibre. Infine, il modello di pelle 3D ha rivelato che le fibre non tessute di aerogel di cellulosa richiedevano ulteriori esperimenti di contatto cellulare diretto prima di essere esaminate con il modello di pelle 3D.
Tutto ciò considerato, questo nuovo materiale non tessuto in aerogel di cellulosa ha mostrato un grande potenziale per conquistare l'attuale mercato dei materiali per applicazioni biomediche come la medicazione delle ferite, tuttavia sono necessari ulteriori esperimenti.As the demand for materials in biomedical fields grows, aerogels are regarded as promising new materials. Cellulose aerogel is biocompatible, highly porous, and with adjustable mechanical properties and has the potential to be used in wound dressing applications. On the other hand, current aerogels have poor mechanical properties, a lack of simple and scalable processing methods, and difficult fabrication procedures. In this study, an innovative technique called solution blow spinning (SBS) for spinning micro- /nano- fibers has been combined with supercritical carbon dioxide (scCO2) drying for the development of highly porous cellulose aerogel nonwovens (CAN). Bioactive agent thymol was added to the fibers with scCO2 drying to have drug-loaded material. Also, a gas-phase esterification reaction is used for surface modification. In this study, also single fibers were developed with a wet spinning technique in which cellulose was combined with chitosan to increase the antibacterial properties of the fibers.
The fibers were produced during this project and analyzed upon structural and morphological analysis. Scanning electron microscopy (SEM) images were able to show the resulting nanoporous Intra and inter-molecular porosity. The fiber’s biocompatibility was determined by XTT assay, which was able to show the non-toxic properties of fibers. The wound healing properties of the material were confirmed using a cell scratch assay. Similarly, XTT and cell scratch assays with free thymol were performed to examine the interaction of the thymol with cells in the absence of fibers. Mechanical biaxial testing for fiber mechanical assessments was investigated. Finally, the 3D skin model revealed that the cellulose aerogel nonwoven fibers required additional direct cell contact experiments before being examined with the 3D skin model.
All this considered, this novel cellulose aerogel nonwoven material showed great potential for taking over the current market in materials for biomedical applications such as wound dressing, but further experiments are needed
円柱杭群まわりにおける波による洗掘現象に関する研究
Get PDF京都大学0048新制・課程博士博士(工学)甲第18558号工博第3919号新制||工||1602(附属図書館)31458京都大学大学院工学研究科社会基盤工学専攻(主査)教授 平石 哲也, 教授 間瀬 肇, 准教授 馬場 康之学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA
Corrigendum to “Lunar Dust Induces Minimal Pulmonary Toxicity Compared to Earth Dust” [Life Sciences in Space Research, Volume 45, May 2025, Pages 72-80] (Life Sciences in Space Research (2025) 45 (72–80), (S2214552425000252), (10.1016/j.lssr.2025.02.005))
No full textThe author Samaneh Toukhanbeigli has been added. This author was added during the revisions process to the document, but this was not updated in the system and was missed during the proofs. The author contributed greatly to the experiments conducted during revisions
Prediction of pile group scour in waves using support vector machines and ANN
No full textScour around pile groups is rather complicated and not yet fully understood due to the fact that it arises from the triple interaction of fluid–structure–seabed. In this study, two data mining approaches, i.e. Support Vector Machines (SVM) and Artificial Neural Networks (ANN), were applied to estimate the wave-induced scour depth around pile groups. To consider various arrangements of pile groups in the development of the models, datasets collected in the field and laboratory studies were used and arrangement parameters were considered in the models. Several non-dimensional controlling parameters, including the Keulegan–Carpenter number, pile Reynolds number, Shield's parameter, sediment number, gap to diameter ratio and number of piles were used as the inputs. Performances of the developed SVM and ANN models were compared with those of existing empirical methods. Results indicate that the data mining approaches used outperform empirical methods in terms of accuracy. They also indicate that SVM will provide a better estimation of scour depth than ANN (back-propagation/multi-layer perceptron). Sensitivity analysis was also carried out to investigate the relative importance of non-dimensional parameters. It was found that the Keulegan–Carpenter number and gap to diameter ratio have the greatest effect on the equilibrium scour depth around pile groups.</jats:p
The role of elastin fibers in the temporomandibular joint disc: structural-functional study
No full textDrug loaded cellulose–chitosan aerogel microfibers for wound dressing applications
Get PDFCellulose and chitosan have been studied for wound dressing due to their biocompatibility, biodegradability, lower antigenicity, and renewability. The functional and structural characteristics of such biopolymers can be dramatically improved by their transformation into fibrous bioaerogels due to their outstanding characteristics such as low density, high porosity, and large specific surface area. Producing aerogels in the form of fibers and textiles not only can enhance mechanical properties, stiffness, and shapeability of aerogels but also lead to short drying times and scalable production processes. Hereby, wet spun chitosan-cellulose aerogel microfibers (CHCLAFs) in two ratios of 1:5 and 1:10 have been produced by supercritical CO2 (scCO(2)) drying for wound dressing application. The fibers were also loaded with ibuprofen (IBU) through post-treatment scCO(2) impregnation. CHCLAF characteristics in terms of morphology, textural properties, thermal stability, mechanical properties, and in vitro assessment such as drug release, antibacterial properties, cytotoxicity, and wound exudate uptake were analyzed and compared to pure cellulose aerogel microfibers (CLF). Blended CHCLAFs showed a low density (similar to 0.18 g/cm(3)), high porosity (similar to 85%), and large specific surface area (similar to 300 m(2)/g) with a macro-porous outer shell and a nano-porous inner core. The fibers were transformed into braided meshes that were highly water absorbable (similar to 400 wt.%) and bactericidal against escherichia coli and staphylococcus aureus. Furthermore, the fibrous structures showed no cytotoxicity using fibroblast cells, and the hybrid fibers were able to release IBU over 48 h in a sustained manner. The results showed that the CHCLAFs could be used as a promising candidate for wound dressing materials.[GRAPHICS]
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