scholarly journals Novel Techniques to Improve Precise Cell Injection

2021 ◽  
Vol 22 (12) ◽  
pp. 6367
Author(s):  
Walter Linzenbold ◽  
Andreas Fech ◽  
Manuela Hofmann ◽  
Wilhelm K. Aicher ◽  
Markus D. Enderle
Keyword(s):  
Tissue Injury ◽  
Target Position ◽  
Physical Parameters ◽  
Sphincter Muscle ◽  
Urethral Sphincter ◽  
Cell Injection ◽  
High Viability ◽  
Wide Range ◽  
Design Pressure ◽  
Superficial Tissue

We noted recently that the injection of cells with a needle through a cystoscope in the urethral sphincter muscle of pigs failed to deposit them nearby or at the intended target position in about 50% of all animals investigated (n > 100). Increasing the chance for precise cell injection by shotgun approaches employing several circumferential injections into the sphincter muscle bears the risk of tissue injury. In this study, we developed and tested a novel needle-free technique to precisely inject cells in the urethral sphincter tissue, or other tissues, using a water-jet system. This system was designed to fit in the working channels of endoscopes and cystoscopes, allowing a wide range of minimally invasive applications. We analyze key features, including the physical parameters of the injector design, pressure ranges applicable for tissue penetration and cell injections and biochemical parameters, such as different compositions of injection media. Our results present settings that enable the high viability of cells post-injection. Lastly, the method is suitable to inject cells in the superficial tissue layer and in deeper layers, required when the submucosa or the sphincter muscle of the urethra is targeted.

scholarly journals A Computational Study on the Role of Parameters for Identification of Thyroid Nodules by Infrared Images (and Comparison with Real Data)

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4459
Author(s):  
José R. González ◽  
Charbel Damião ◽  
Maira Moran ◽  
Cristina A. Pantaleão ◽  
Rubens A. Cruz ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thyroid Nodules ◽  
Numerical Study ◽  
Computational Study ◽  
Internal Heat ◽  
Heat Transfer Process ◽  
The Body ◽  
Physical Parameters ◽  
Infrared Sensors ◽  
Wide Range

According to experts and medical literature, healthy thyroids and thyroids containing benign nodules tend to be less inflamed and less active than those with malignant nodules. It seems to be a consensus that malignant nodules have more blood veins and more blood circulation. This may be related to the maintenance of the nodule’s heat at a higher level compared with neighboring tissues. If the internal heat modifies the skin radiation, then it could be detected by infrared sensors. The goal of this work is the investigation of the factors that allow this detection, and the possible relation with any pattern referent to nodule malignancy. We aim to consider a wide range of factors, so a great number of numerical simulations of the heat transfer in the region under analysis, based on the Finite Element method, are performed to study the influence of each nodule and patient characteristics on the infrared sensor acquisition. To do so, the protocol for infrared thyroid examination used in our university’s hospital is simulated in the numerical study. This protocol presents two phases. In the first one, the body under observation is in steady state. In the second one, it is submitted to thermal stress (transient state). Both are simulated in order to verify if it is possible (by infrared sensors) to identify different behavior referent to malignant nodules. Moreover, when the simulation indicates possible important aspects, patients with and without similar characteristics are examined to confirm such influences. The results show that the tissues between skin and thyroid, as well as the nodule size, have an influence on superficial temperatures. Other thermal parameters of thyroid nodules show little influence on surface infrared emissions, for instance, those related to the vascularization of the nodule. All details of the physical parameters used in the simulations, characteristics of the real nodules and thermal examinations are publicly available, allowing these simulations to be compared with other types of heat transfer solutions and infrared examination protocols. Among the main contributions of this work, we highlight the simulation of the possible range of parameters, and definition of the simulation approach for mapping the used infrared protocol, promoting the investigation of a possible relation between the heat transfer process and the data obtained by infrared acquisitions.

scholarly journals Seed germination requirements of Hypericum scruglii, an endangered medicinal plant species of Sardinia (Italy)

Botany ◽  
2020 ◽  
Vol 98 (10) ◽  
pp. 615-621 ◽  
Author(s):  
Marco Porceddu ◽  
Martina Sanna ◽  
Sara Serra ◽  
Maria Manconi ◽  
Gianluigi Bacchetta
Keyword(s):  
Medicinal Plant ◽  
Seed Bank ◽  
Seed Viability ◽  
Base Temperature ◽  
Endemic Plant ◽  
Endangered Medicinal Plant ◽  
High Viability ◽  
Wide Range ◽  
Baseline Information ◽  
Germination Requirements

Hypericum scruglii Bacch., Brullo & Salmeri is an endangered endemic plant of Sardinia, and the phloroglucinol compounds identified in this species have been reported to inhibit the activity of the Human Immunodeficiency Virus. Seed banks are a genetic repository that effectively preserve taxa of conservation interest, and they hold knowledge about the biology and germination ecophysiology of the taxa they preserve. The main goals of this study were to investigate the germination requirements for H. scruglii, to evaluate the seed viability after eight years of long-term conservation and to suggest an efficient protocol for germination. Seeds stored at –25 °C in the seed bank were tested at temperatures from 5 to 30 °C and 25/10 °C. Base temperature (Tb) and thermal time (θ50) for germination were estimated. Seeds of H. scruglii germinated over a wide range of temperatures, responding positively to high temperatures and 25/10 °C. Tb was estimated at 4.92 °C, and θ50 was estimated at 198.27 degree days. The high viability detected in seeds of H. scruglii allows us to suggest the use of seeds stored in a seed bank when fresh material for plant propagation is scarce. Our results provide new and useful baseline information for implementing conservation and multiplication strategies for this endangered medicinal plant.

scholarly journals Modelling H2 and its effects on star formation using a joint implementation of gadget-3 and KROME

2021 ◽  
Vol 504 (2) ◽  
pp. 2325-2345
Author(s):  
Emanuel Sillero ◽  
Patricia B Tissera ◽  
Diego G Lambas ◽  
Stefano Bovino ◽  
Dominik R Schleicher ◽  
...  
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
Physical Parameters ◽  
Density Profiles ◽  
Star Forming ◽  
Chemical Enrichment ◽  
Numerical Resolution ◽  
Stellar Radiation ◽  
Wide Range ◽  
The Impact

ABSTRACT We present p-gadget3-k, an updated version of gadget-3, that incorporates the chemistry package krome. p-gadget3-k follows the hydrodynamical and chemical evolution of cosmic structures, incorporating the chemistry and cooling of H2 and metal cooling in non-equilibrium. We performed different runs of the same ICs to assess the impact of various physical parameters and prescriptions, namely gas metallicity, molecular hydrogen formation on dust, star formation recipes including or not H2 dependence, and the effects of numerical resolution. We find that the characteristics of the simulated systems, both globally and at kpc-scales, are in good agreement with several observable properties of molecular gas in star-forming galaxies. The surface density profiles of star formation rate (SFR) and H2 are found to vary with the clumping factor and resolution. In agreement with previous results, the chemical enrichment of the gas component is found to be a key ingredient to model the formation and distribution of H2 as a function of gas density and temperature. A star formation algorithm that takes into account the H2 fraction together with a treatment for the local stellar radiation field improves the agreement with observed H2 abundances over a wide range of gas densities and with the molecular Kennicutt–Schmidt law, implying a more realistic modelling of the star formation process.

Data-Driven Analysis of Engine Mission Severity Using Non-Dimensional Groups

2021 ◽  
Author(s):  
Tim Brandes ◽  
Stefano Scarso ◽  
Christian Koch ◽  
Stephan Staudacher
Keyword(s):  
Support Vector Machine ◽  
Computation Time ◽  
Principal Component ◽  
General Term ◽  
Support Vector ◽  
Physical Parameters ◽  
Machine Model ◽  
Precision Error ◽  
Operational Conditions ◽  
Wide Range

Abstract A numerical experiment of intentionally reduced complexity is used to demonstrate a method to classify flight missions in terms of the operational severity experienced by the engines. In this proof of concept, the general term of severity is limited to the erosion of the core flow compressor blade and vane leading edges. A Monte Carlo simulation of varying operational conditions generates a required database of 10000 flight missions. Each flight is sampled at a rate of 1 Hz. Eleven measurable or synthesizable physical parameters are deemed to be relevant for the problem. They are reduced to seven universal non-dimensional groups which are averaged for each flight. The application of principal component analysis allows a further reduction to three principal components. They are used to run a support-vector machine model in order to classify the flights. A linear kernel function is chosen for the support-vector machine due to its low computation time compared to other functions. The robustness of the classification approach against measurement precision error is evaluated. In addition, a minimum number of flights required for training and a sensible number of severity classes are documented. Furthermore, the importance to train the algorithms on a sufficiently wide range of operations is presented.

Age and multiparity related urethral sphincter muscle dysfunction in a rabbit model: Potential roles of TGF‐β and Wnt‐β catenin signaling pathways

2018 ◽  
Vol 38 (2) ◽  
pp. 607-614 ◽  
Author(s):  
Mahadevan R. Rajasekaran ◽  
Johnny Fu ◽  
My‐Uyen (Lilly) Nguyen ◽  
Yaozhi Wang ◽  
Michael Albo ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Rabbit Model ◽  
Model Potential ◽  
Muscle Dysfunction ◽  
Sphincter Muscle ◽  
Urethral Sphincter

scholarly journals Optical tools for ocean monitoring and research

Ocean Science ◽  
2009 ◽  
Vol 5 (4) ◽  
pp. 661-684 ◽  
Author(s):  
C. Moore ◽  
A. Barnard ◽  
P. Fietzek ◽  
M. R. Lewis ◽  
H. M. Sosik ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ocean Color ◽  
Analytical Techniques ◽  
Optical Measurements ◽  
Physical Parameters ◽  
Optical Tools ◽  
Wide Range ◽  
Radiance Distribution ◽  
Ocean Monitoring ◽  
Methane Carbon

Abstract. Requirements for understanding the relationships between ocean color and suspended and dissolved materials within the water column, and a rapidly emerging photonics and materials technology base for performing optical based analytical techniques have generated a diverse offering of commercial sensors and research prototypes that perform optical measurements in water. Through inversion, these tools are now being used to determine a diverse set of related biogeochemical and physical parameters. Techniques engaged include measurement of the solar radiance distribution, absorption, scattering, stimulated fluorescence, flow cytometry, and various spectroscopy methods. Selective membranes and other techniques for material isolation further enhance specificity, leading to sensors for measurement of dissolved oxygen, methane, carbon dioxide, common nutrients and a variety of other parameters. Scientists are using these measurements to infer information related to an increasing set of parameters and wide range of applications over relevant scales in space and time.

scholarly journals Numerical Model for the Analysis of Thermal Transients in District Heating Networks

2020 ◽  
Vol 197 ◽  
pp. 01004
Author(s):  
Martina Capone ◽  
Elisa Guelpa ◽  
Vittorio Verda
Keyword(s):  
Carbon Dioxide Emissions ◽  
Renewable Energy Sources ◽  
Management Strategies ◽  
District Heating ◽  
Equivalent Model ◽  
Computational Time ◽  
Physical Parameters ◽  
Thermal Transients ◽  
Proposed Model ◽  
Wide Range

As District Heating (DH) networks are experiencing an evolution towards the so-called 4th generation, there is a need to update the currently used models to take into account the ever-increasing complexity of this technology. Indeed, to further improve the reduction in energy consumption and carbon-dioxide emissions, a wide range of technologies and management strategies are being introduced within district heating, such as a large exploitation of Renewable Energy Sources (RES). As a consequence, thermal transients assume a major importance, posing the need to redefine the relevant physical parameters and to develop a model which accurately describes their behaviour. In this framework, this paper proposes a quantitative analysis of the influence of the pipe heat-capacity on the model. Moreover, an equivalent-model, which is able to take into account the two heat capacities of steel and water in just one equation, is proposed and compared with two commonly used approaches. One of the features of the proposed model is the suitability for application to large networks. To prove its capabilities, an application to the Turin district heating network, which is among the largest systems in Europe, is proposed. Results show significant improvements in terms of accuracy over computational time ratio.

Non-Linear Dynamic Magneto Electric Effects in Ferromagnetic-Ferroelectric Layered Composites

2013 ◽  
Author(s):  
Satenik Harutyunyan ◽  
Davresh Hasanyan
Keyword(s):  
Vibration Frequency ◽  
Strain Distribution ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Low Frequency ◽  
Structure Design ◽  
Experimental Results ◽  
Physical Parameters ◽  
Wide Range ◽  
Non Linear

A non-linear theoretical model including bending and longitudinal vibration effects was developed for predicting the magneto electric (ME) effects in a laminate bar composite structure consisting of magnetostrictive and piezoelectric multi-layers. If the magnitude of the applied field increases, the deflection rapidly increases and the difference between experimental results and linear predictions becomes large. However, the nonlinear predictions based on the present model well agree with the experimental results within a wide range of applied electric field. The results of the analysis are believed to be useful for materials selection and actuator structure design of actuator in actuator fabrication. It is shown that the problem for bars of symmetrical structure is not divided into a plane problem and a bending problem. A way of simplifying the solution of the problem is found by an asymptotic method. After solving the problem for a laminated bar, formula that enable one to change from one-dimensional required quantities to three dimensional quantities are obtained. The derived analytical expression for ME coefficients depend on vibration frequency and other geometrical and physical parameters of laminated composites. Parametric studies are presented to evaluate the influences of material properties and geometries on strain distribution and the ME coefficient. Analytical expressions indicate that the vibration frequency strongly influences the strain distribution in the laminates, and that these effects strongly influence the ME coefficients. It is shown that for certain values of vibration frequency (resonance frequency), the ME coefficient becomes infinity; as a particular case, low frequency ME coefficient were derived as well.

The Validity of the Reynolds Equation in Modeling Hydrostatic Effects in Gas Lubricated Textured Parallel Surfaces

2005 ◽  
Vol 128 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Y. Feldman ◽  
Y. Kligerman ◽  
I. Etsion ◽  
S. Haber
Keyword(s):  
Carrying Capacity ◽  
Reynolds Equation ◽  
Stokes Equations ◽  
Surface Texturing ◽  
Laser Surface Texturing ◽  
Physical Parameters ◽  
Load Carrying Capacity ◽  
Wide Range ◽  
Load Carrying ◽  
Parallel Surfaces

Microdimples generated by laser surface texturing (LST) can be used to enhance performance in hydrostatic gas-lubricated tribological components with parallel surfaces. The pressure distribution and load carrying capacity for a single three-dimensional dimple, representing the LST, were obtained via two different methods of analysis: a numerical solution of the exact full Navier-Stokes equations, and an approximate solution of the much simpler Reynolds equation. Comparison between the two solution methods illustrates that, despite potential large differences in local pressures, the differences in load carrying capacity, for realistic geometrical and physical parameters, are small. Even at large clearances of 5% of the dimple diameter and pressure ratios of 2.5 the error in the load carrying capacity is only about 15%. Thus, for a wide range of practical clearances and pressures, the simpler, approximate Reynolds equation can safely be applied to yield reasonable predictions for the load carrying capacity of dimpled surfaces.

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