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Characterization of the Topography and Wettability of English Weed Leaves and biomimetic Replicas

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Journal of bionic Engineering 2014年第3期11卷 346-359页

作者： Pedro Miguel Matos Pereira Ana sofia Moita Gabriel Amaro Monteiro duarte Miguel franca Prazeres Ibb - Institute for biotechnology and bioengineering Centre for Biological and Chemical Engineering Department of Bioengineering Instituto Superior Tecnico Universidade de Lisboa Av. Rovisco Pals 1049-001 Lisboa Portugal IN+ - Center for Innovation Technology and Policy Research Instituto Superior T~cnico Universidade de Lisboa Av. Rovisco Pais 1049-001 Lisboa Portugal

The topography and wettability of the underside of English weed （Oxalis pes-caprae） leaves and of their biomimetic replicas are investigated. Polyvinyl siloxane molds were cast from the leaves and then filled with an epoxy pre-polymer to produce replicas. The particular topographical structures of leaves and replicas were evaluated by optical microscopy and Scanning Electron Microscopy （SEM） analysis. The static wettability of leaves and replicas was assessed by contact angle measurements, while the dynamic wettability was characterized by estimating contact angle hysteresis and studying the dynamic behavior of impacting water droplets. A smooth glass slip and its replica were used as control surfaces. The replica moulding method used was able to transfer the characteristic pattern of irregular 100 μm - 200 μm × 60 μm convex papillae interspersed with stomata of the original leaf to the epoxy replicas. The static contact angle of 143°± 3° and the contact angle hysteresis of 2~ indicate that the underside of the English weed leaf is close to superhydrophobic. The lower contact angles （130° ± 4°） and higher hysteresis （31°） observed for the replica when compared with the original leaves were associated to an inaccurate replication of the chemistry and structures of the three-dimensional wax projections covering the plant surface. Also, trichomes in the original leaves could not be accurately reproduced due to their flexibility and fragility. Differences in wetting behavior were also evident from droplet impact experiments, with rebound regimes prevailing in the original leaves and regimes characterized by higher adhesion and larger dissipation predominating in the replicas. Nevertheless, the morphological features of the leaf transferred to the replica were sufficient to promote a clear hydrophobic behavior of the replica when compared with the smooth epoxy reference surface.

关键词： biomimetic surfaces oxalis pes-caprae English weed replica molding wettability micro-topography

Cell-based therapeutic strategies for treatment of spinocerebellar ataxias:an update

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Neural Regeneration Research 2023年第6期18卷 1203-1212页

作者： Joana sofia Correia Sara duarte-Silva António JoséSalgado Patrícia Maciel Life and Health Sciences Research Institute(ICVS) School of MedicineUniversity of MinhoBragaPortugal ICVS/3b’s–PT Government Associate Laboratory BragaGuimarãesPortugal

Spinocerebellar ataxias are heritable neurodegenerative diseases caused by a cytosine-adenine-guanine expansion,which encodes a long glutamine tract(polyglutamine)in the respective wild-type protein causing misfolding and protein *** features of polyglutamine spinocerebellar ataxias include neuronal aggregation,mitochondrial dysfunction,decreased proteasomal activity,and autophagy *** polyglutamine protein aggregates accumulate within neurons and cause neural dysfunction and death in specific regions of the central nervous *** ataxias are mostly characterized by progressive ataxia,speech and swallowing problems,loss of coordination and gait *** the past decade,efforts have been made to ameliorate disease symptoms in patients,yet no cure is *** studies have been proposing the use of stem cells as promising tools for central nervous system tissue *** far,pre-clinical trials have shown improvement in various models of neurodegenerative diseases following stem cell transplantation,including animal models of spinocerebellar ataxia types 1,2,and ***,contrasting results can be found in the literature,depending on the animal model,cell type,and route of administration ***,clinical trials using cellular implants into degenerated brain regions have already been applied,with the expectation that these cells would be able to differentiate into the specific neuronal subtypes and re-populate these regions,reconstructing the affected neural ***,the question of how feasible it is to continue such treatments remains unanswered,with long-lasting effects being still *** establish the value of these advanced therapeutic tools,it is important to predict the actions of the transplanted cells as well as to understand which cell type can induce the best outcomes for each *** studies are needed to determine the best route of administration,without neglec

关键词： cell transplantation engraftment induced pluripotent stem cells mesenchymal stem cells neural progenitor cells neuroprotection polyglutamine spinocerebellar ataxias secretome spinocerebellar ataxia stem cell therapy

Dynamics of Droplets of biological fluids on Smooth Superhydrophobic Surfaces under Electrostatic Actuation

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Journal of bionic Engineering 2016年第2期13卷 220-234页

作者： Ana sofia Moita Catarina Laurencia Joana Anastacio Ramos duarte Miguel franca Prazeres Antonio Luis Nobre Moreira IN+ - Center for Innovation Technology and Policy Research Instituto Superior Tecnico Universidade de Lisboa Av. Rovisco Pais 1049-001 Lisboa Portugal ibb - Institute for bioengineering and biosciences Department of Bioengineering Instituto Superior Tecnico Universidade de Lisboa Av. Rovisco Pais 1049-001 Lisboa Portugal

This study describes the dynamic behaviour of droplets of biological liquids on hydrophobic surfaces under electrostatic actuation, to devise sample handling in lab-on-chip diagnostic tools. bovine Serum Albumin （bSA） is taken as a representative biomolecule, since it is often used in adsorption studies. Green fluorescence Protein （GfP） is also considered, given its natural fluorescence. Several effects such as sample concentration and pH are discussed. The results show negligible effects of proteins concentration in electrowetting, although increased concentrations endorse passive adsorption mechanisms, which alter the local wettability of the substrates precluding droplet motion. bioinspired surfaces promote the largest spreading diameter, which is beneficial for droplet motion. However, surface roughness promotes energy dissipation limiting the receding droplet motion. Hence, the most effective approach is altering the surface chemistry. The coating is applied to a surface with a mean roughness smaller than 20 nm and does not alter significantly the topography, thus leading to the so-called smooth superhydrophobic surface. This coating also reduces passive proteins adsorption, as confirmed by Confocal Microscopy （CM）, which is beneficial for droplet motion. Evaluating absorption spectra of protein solutions evidences an increase in protein concentration ascribed to droplet evaporation as confirmed by theoretical analysis and time resolved infrared visualization.

关键词： bioinspired surfaces biofluids electrostatic actuation hydrophobicity adsorption evaporation

Pylephlebitis—a rare complication of a fish bone migration mimicking metastatic pancreatic cancer:A case report

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World Journal of Clinical Cases 2021年第23期9卷 6768-6774页

作者： sofia bezerra Nuno J frança firmo Mineiro Germano Capela Cristina duarte António Ribeiro Mendes Department of Surgery Centro Hospitalar do Médio TejoTomar 2304-909Portugal

bACKGROUND Pylephlebitis is a rare condition,poorly recognized by clinicians and with few *** this case,the clinical appearance resembled the clinical course of a pancreatic cancer and was originated by the ingestion of a fish bone,making the case more interesting and *** SUMMARY A 79-year-old female presented to the emergency department with fever,loss of appetite and *** in the right upper quadrant was *** marker were high.A computed tomography(CT)scan revealed gallstones and aspects compatible with acute *** patient was admitted to surgery ward and has her condition aggravated.A magnetic resonance revealed multifocal liver ***,a cholangiopancreatography and an endoscopic ultrasound(US)were able to diagnose the *** treatment was implemented and the patient made a complete *** In conclusion,this case report demonstrates for the first time the diagnosis of an unusual case of pylephlebitis complicated by the migration of a fish bone,mimicking metastatic pancreatic *** presentation and traditional imaging studies,such as transabdominal US and CT,remain the standard for diagnosing this condition.

关键词： Pylephlebitis Portal vein thrombosis Abdominal infection fish bone Pancreatic cancer Case report