From Cell to Tissue Properties—Modeling Skin Electroporation With Pore and Local Transport Region Formation

2018 ◽  
Vol 65 (2) ◽  
pp. 458-468 ◽  
Author(s):  
Janja Dermol-Cerne ◽  
Damijan Miklavcic
Keyword(s):  
Tissue Properties ◽  
Local Transport ◽  
Transport Region

Experimental Factors to Be Considered in Electroporation-Mediated Transdermal Diffusion Experiments

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Nataša Pavšelj ◽  
Barbara Zorec ◽  
Damijan Miklavčič ◽  
Sid Becker
Keyword(s):  
Mass Transport ◽  
Stratum Corneum ◽  
Pulse Shape ◽  
Analytical Investigation ◽  
Potential Difference ◽  
Franz Cell ◽  
Transport Measurements ◽  
Long Duration ◽  
Local Transport ◽  
Transport Region

In this paper, we discuss some of the primary experimental factors that should be considered when interpreting and implementing the published results of skin electroporation studies concerning measurements of mass transport across the stratum corneum (SC) in the Franz cell. It is explained that the pulse magnitude should always be considered in the context of pulse shape and that transport measurements should always be presented in the context of the trans-SC potential difference (instead of the voltage between the electrodes). The condition of the SC prior to the application of the long-duration pulse strongly influences the evolution of the local transport region (LTR). This is quantified in a simple analytical investigation of the conditions that affect the thermodynamic response of the skin.

scholarly journals Quantitative Measurement of Macromolecular Tissue Properties in White and Gray Matter in Healthy Aging and Amnestic MCI

NeuroImage ◽  
2021 ◽  
pp. 118161
Author(s):  
Elveda Gozdas ◽  
Hannah Fingerhut ◽  
Hua Wu ◽  
Jennifer L. Bruno ◽  
Lauren Dacorro ◽  
...  
Keyword(s):  
Gray Matter ◽  
Healthy Aging ◽  
Quantitative Measurement ◽  
Tissue Properties ◽  
Amnestic Mci

scholarly journals A Quasi-Static Quantitative Ultrasound Elastography Algorithm Using Optical Flow

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3010
Author(s):  
Raphael Lamprecht ◽  
Florian Scheible ◽  
Marion Semmler ◽  
Alexander Sutor
Keyword(s):  
Optical Flow ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Young's Modulus ◽  
Image Data ◽  
Maximum Error ◽  
Ultrasound Elastography ◽  
Static Compression ◽  
Tissue Properties ◽  
A Performance

Ultrasound elastography is a constantly developing imaging technique which is capable of displaying the elastic properties of tissue. The measured characteristics could help to refine physiological tissue models, but also indicate pathological changes. Therefore, elastography data give valuable insights into tissue properties. This paper presents an algorithm that measures the spatially resolved Young’s modulus of inhomogeneous gelatin phantoms using a CINE sequence of a quasi-static compression and a load cell measuring the compressing force. An optical flow algorithm evaluates the resulting images, the stresses and strains are computed, and, conclusively, the Young’s modulus and the Poisson’s ratio are calculated. The whole algorithm and its results are evaluated by a performance descriptor, which determines the subsequent calculation and gives the user a trustability index of the modulus estimation. The algorithm shows a good match between the mechanically measured modulus and the elastography result—more precisely, the relative error of the Young’s modulus estimation with a maximum error 35%. Therefore, this study presents a new algorithm that is capable of measuring the elastic properties of gelatin specimens in a quantitative way using only the image data. Further, the computation is monitored and evaluated by a performance descriptor, which measures the trustability of the results.

scholarly journals Privileging Electric Vehicles as an Element of Promoting Sustainable Urban Mobility—Effects on the Local Transport System in a Large Metropolis in Poland

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3838
Author(s):  
Marta Borowska-Stefańska ◽  
Michał Kowalski ◽  
Paulina Kurzyk ◽  
Miroslava Mikušová ◽  
Szymon Wiśniewski
Keyword(s):  
Transport System ◽  
Electric Vehicles ◽  
Traffic Management ◽  
Negative Impact ◽  
Software Tool ◽  
Research Area ◽  
Shopping Centre ◽  
Local Transport ◽  
Sustainable Urban Mobility ◽  
The Impact

The main purpose of this article was to determine the impact on the equilibrium of the local transport system from privileging EVs by permitting them to use bus lanes. The study used two sets of data: information on infrastructure and traffic management; and information on the recorded road network loads and traffic volumes generated by a given shopping centre—the E. Leclerc shopping centre (an important traffic generator within the city of Łódź, Poland). These sets were then used to develop a microsimulation traffic model for the shopping centre and the associated effects on the localised transport system. The model was constructed by means of the PTV Vissim software tool. An initial simulation was conducted that formed a basis for subsequent scenarios (in total, 17 simulations were performed). On the basis of the conducted analyses, it was established that—for the researched part of the transport system—privileging the still rather uncommon battery electric vehicles (BEVs) engendered a marginal deterioration of traffic conditions. At the same time, allowing BEVs to use bus lanes within the chosen research area had no negative impact on bus journey times.

Prognostic utility of differential contrast-enhancement patterns on late gadolinium enhancement cardiac MRI (LGE-CMR) in patients with cancer-associated cardiac masses

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Chan ◽  
W Dinsfriend ◽  
J Kim ◽  
R Steingart ◽  
J.W Weinsaft
Keyword(s):  
Contrast Enhancement ◽  
Cancer Patients ◽  
Cancer Type ◽  
Tissue Properties ◽  
All Cause Mortality ◽  
Prognostic Utility ◽  
Cardiac Masses ◽  
Embolic Risk ◽  
Lge Cmr

Abstract Background LGE-CMR tissue characterization is widely used to identify cardiac masses (CMASS) in cancer patients – including neoplasm (NEO) and thrombus (THR). Prognostic utility of their differential LGE patterns is unknown. Purpose To determine incremental prognostic utility of LGE patterns in CMASS Methods The population comprised of cancer patients with CMASS on LGE-CMR, for which etiology was classified based on presence (NEO) or absence (THR) of enhancement, and controls matched for cancer type/stage. LGE-CMR tissue properties of NEO was classified based on extent of contrast enhancement – diffusely enhancing (DE), mixed (ME), and predominantly avascular (PA). Clinical follow up was performed for embolic events within 6 months of CMR and all-cause mortality. Results 330 cancer patients (55% M; 55±16yo) with an array of cancer diagnoses (19% sarcoma, 17% GI, 13% GU) were studied. Among CMASS+ pts (n=190), 66% had NEO and 34% had THR on LGE. All THR were non-enhancing. Among NEO, LGE pattern was variable (46% DE, 41% ME, 13% PA); ME lesions were larger than other groups (Fig. 1A). Quantitative tissue properties were consistent with qualitative groups, as evidenced by stepwise variation in signal intensity and CNR. Cumulative embolic events were 3-fold higher in CMASS+ than controls (All: 20% vs. 7%, p=0.001; PE: 13% vs. 5%, p=0.02; CVA/systemic embolism: 10% vs. 3%, p=0.01). Median time to event was 1.3 months [IQR 0.1–2.3] from CMR. Aggregate events were similar between NEO and THR, reflecting similar rates of PE and CVA (p=NS). Among CMASS pts with embolic events, 56% were on anticoagulation at time of event (59% NEO, 50% THR, p=0.61). Regarding CMASS morphology, emboli were 3-fold higher among intracavitary (IC) or highly mobile (HM) CMASS (IC: 25% vs 7%, p<0.001; HM: 38% vs 12%, p=0.001). Regarding location, right sided CMASS were associated with a 3–5 fold increase in PE (IC: 19% vs 6%; HM: 35% vs 7%, both p<0.001) and similar CVA events among left sided CMASS (IC: 17% vs. 6%, p=0.02; HM: 33% vs 6%, p=0.05). Embolic events were similar when partitioned based on quantitative LGE patterns between patients with and without embolic events. As for all-cause mortality, NEO on CMR conferred increased mortality than THR (HR 3.06 [CI=1.84–5.1], p<0.001) and matched controls (HR 2.08 [CI=1.42–3.04], p<0.001) during a median follow-up of 9.4 months [IQR 3.6–23.2]. Among NEO subgroups (Fig. 1B), survival was lower in patients with heterogeneous LGE patterns vs matched controls: the lowest survival in ME (p=0.002) suggests increased vascularity and tumor hypoxia/necrosis associated with aggressive tumors and hence larger lesions. Conclusions Among cancer patients, CMR-evidenced CMASS confers high short-term embolic risk, which are equivalently common between NEO and THR. Intra-cavitary location and increased mobility augment embolic risk irrespective of CMASS tissue properties whereas differential LGE patterns on CMR strongly impact prognosis. Funding Acknowledgement Type of funding source: None

scholarly journals Mechanical Enhancement of Cytocompatible 3D Scaffolds, Consisting of Hydroxyapatite Nanocrystals and Natural Biomolecules, Through Physical Cross-Linking

2020 ◽  
Vol 7 (3) ◽  
pp. 96
Author(s):  
Despoina Brasinika ◽  
Elias P. Koumoulos ◽  
Kyriaki Kyriakidou ◽  
Eleni Gkartzou ◽  
Maria Kritikou ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Cell Attachment ◽  
Great Promise ◽  
Porous Network ◽  
Mechanical Reinforcement ◽  
Experimental Conditions ◽  
Tissue Properties ◽  
Human Osteosarcoma Cells ◽  
Hydroxyapatite Nanocrystals ◽  
Physical Crosslinking

Bioinspired scaffolds mimicking natural bone-tissue properties holds great promise in tissue engineering applications towards bone regeneration. Within this work, a way to reinforce mechanical behavior of bioinspired bone scaffolds was examined by applying a physical crosslinking method. Scaffolds consisted of hydroxyapatite nanocrystals, biomimetically synthesized in the presence of collagen and l-arginine. Scaffolds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), microcomputed tomography, and nanoindentation. Results revealed scaffolds with bone-like nanostructure and composition, thus an inherent enhanced cytocompatibility. Evaluation of porosity proved the development of interconnected porous network with bimodal pore size distribution. Mechanical reinforcement was achieved through physical crosslinking with riboflavin irradiation, and nanoindentation tests indicated that within the experimental conditions of 45% humidity and 37 °C, photo-crosslinking led to an increase in the scaffold’s mechanical properties. Elastic modulus and hardness were augmented, and specifically elastic modulus values were doubled, approaching equivalent values of trabecular bone. Cytocompatibility of the scaffolds was assessed using MG63 human osteosarcoma cells. Cell viability was evaluated by double staining and MTT assay, while attachment and morphology were investigated by SEM. The results suggested that scaffolds provided a cell friendly environment with high levels of viability, thus supporting cell attachment, spreading and proliferation.

scholarly journals Publisher Correction: Diattenuation Imaging reveals different brain tissue properties

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Miriam Menzel ◽  
Markus Axer ◽  
Katrin Amunts ◽  
Hans De Raedt ◽  
Kristel Michielsen
Keyword(s):  
Brain Tissue ◽  
Tissue Properties
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