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A microfluidic cell capture device was designed, fabricated, evaluated by numerical simulations and validated experimentally. The cell capture device was designed with a minimal footprint compartment comprising internal micropillars with the goal to obtain a compact, integrated bioanalytical system. The design of the device was accomplished by computational fluid dynamics (CFD) simulations. Various microdevice designs were rapidly prototyped in poly-dimethylsiloxane using conventional soft lithograpy technique applying micropatterned SU-8 epoxy based negative photoresist as moulding replica. The numerically modeled flow characteristics of the cell capture device were experimentally validated by tracing and microscopic recording the flow trajectories using yeast cells. Finally, we give some perspectives on how CFD modeling can be used in the early stage of microfluidics-based cell capture device development.
This study focuses on the drop foot case related to hyperthyroidism of the ankle joint resulting in the relaxation of the toes during walking. This condition requires treatment using an ankle-foot orthosis. Traditional orthosis techniques lack precision and depend on the skill of the fabricator. This research aims to make a bias in ankle-foot orthosis design and analysis methods, where a complete methodology of numerical design and testing has been proposed using advanced engineering software. A numerical model of the patient's foot was generated and used to design an ankle-foot orthosis model using SolidWorks. The designed model was mechanically analyzed by the finite element method using ANSYS Workbench 16.1 under different static and dynamic loading conditions. The ankle-foot orthosis model was numerically designed and analyzed before the manufacturing process. This is believed to reduce time and material loss and foster the use of numerical models in biomedical applications. This study suggests focusing on the design and analysis of orthoses according to the patient's measurements. This is expected to increase the comfort and raise the level of treatment. Numerical design methods also enable precise manufacturing using computerized devices such as three-dimensional printers.
- Klíčová slova
- Drop foot, ankle–foot orthosis, energy dissipation, finite element analysis, rotational hardness,
- MeSH
- analýza metodou konečných prvků MeSH
- biomechanika MeSH
- chůze fyziologie MeSH
- design s pomocí počítače MeSH
- design vybavení metody MeSH
- hlezenní kloub fyziologie MeSH
- lidé MeSH
- neurologické poruchy chůze * etiologie patofyziologie terapie MeSH
- ortézy nohy (od hlezna dolů) * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Diamond thin films have remarkable properties comparable with natural diamond. Because of these properties it is a very promising material for many various applications (sensors, heat sink, optical mirrors, chemical and radiation wear, cold cathodes, tissue engineering, etc.) In this paper we report about design, deposition and measurement of properties of optical planar waveguides fabricated from nanocrystalline diamond thin films. The nanocrystalline diamond planar waveguide was deposited by microwave plasma enhanced chemical vapor deposition and the structure of the deposited film was studied by scanning electron microscopy and Raman spectroscopy. The design of the presented planar waveguides was realized on the bases of modified dispersion equation and was schemed for 632.8 nm, 964 nm, 1 310 nm and 1 550 nm wavelengths. Waveguiding properties were examined by prism coupling technique and it was found that the diamond based planar optical element guided one fundamental mode for all measured wavelengths. Values of the refractive indices of our NCD thin film measured at various wavelengths were almost the same as those of natural diamond.
- MeSH
- analýza selhání vybavení MeSH
- design vybavení MeSH
- diamant chemie MeSH
- krystalizace MeSH
- nanočástice chemie MeSH
- nanotechnologie přístrojové vybavení MeSH
- povrchová plasmonová rezonance přístrojové vybavení MeSH
- refraktometrie přístrojové vybavení MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- diamant MeSH
The recent pandemic has shown that protecting the general population from hazardous substances or pathogens can be a challenging and urgent task. The key element to adequate protection is appropriately sized, well-fitted and sufficiently distributed personal protective equipment (PPE). While these conditions are followed for adult PPE wearers, they are less considered when it comes to protecting subadults. In this study, the assessment of the fit and design improvements of a 3D-printed facial half mask for subadult wearers (4-18 years) is designed. The target population was represented by 1137 subadults, aged 4.06-18.94 years, for whom 3D face models were acquired. The half mask tested, which was originally provided in one subadult size, did not fit appropriately the target population. This finding prompted the creation of four size categories using the age-dependent distribution of the centroid size calculated from 7 facial landmarks. For each size category, a modified half-mask virtual design was created, including resizing and reshaping, and fit was evaluated visually and numerically using averaged and random 3D face representatives.Practitioner summary: The reason for this study was to describe procedures which led to design improvement of an existing half-mask and provide respiratory protection for subadults. To address this, fit was assessed using an innovative metric approach. Four sizes were then created based on centroid size, resulting in improved fit and design.Abbreviations: CH: cheilion landmark; CS: centroid size; EX: exocanthion landmark; GN: gnathion landmark; N: nasion landmark; PPE: personal protective equipment; PR: pronasale landmark; RPE: respiratory protective equipment.
3D human face dataset was used for modifying and validating protective equipment for subadultsTo ensure optimal protection for subadults, four size categories were proposed based on 3D face landmarks and centroid sizeModified half-mask design fit was validated virtually using a visual and numerical approach.
- Klíčová slova
- 3D face database, Personal protective equipment, centroid size, sizing system, subadults, virtual design, virtual fit assessment,
- MeSH
- 3D tisk MeSH
- COVID-19 prevence a kontrola MeSH
- design vybavení * MeSH
- dítě MeSH
- lidé MeSH
- masky * MeSH
- mladiství MeSH
- obličej MeSH
- předškolní dítě MeSH
- prostředky na ochranu dýchání MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Gloves that attenuate vibration above approximately 25 Hz and that exceed the characteristics of standard viscoelastic gloves have been developed using an air bladder system in the palm and fingers of a glove. Testing was performed on a variety of viscoelastic gloves currently marketed to obtain the ratio of energy leaving the handle of a vibrating device and the energy entering the hand. Several simple rectangular air bladders of varying thickness were developed and tested for their vibration attenuating characteristics. A four degree-of-freedom, lumped-parameter model of the vibration response of the human and air bladder was developed using measured hand and bladder parameters. This model, along with subjective criteria, was used to design and fabricate two prototype air bladder gloves. These gloves were tested and found to exceed adopted standard requirements and the characteristics of standard viscoelastic gloves. The prototypes in this study will be further developed, adapted and marketed for practical applications.
- MeSH
- design vybavení MeSH
- lidé MeSH
- nemoci z povolání etiologie prevence a kontrola MeSH
- ochranné rukavice * MeSH
- pružnost MeSH
- vibrace škodlivé účinky MeSH
- viskozita MeSH
- vzduch MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
This paper describes possible ways of prediction of nitrogen oxides formation during combustion of hydrocarbon fuels. Mathematical model based on experimental data acquired from the testing facility has been developed. The model enables to predict--at a high probability measure--the extent of nitrogen oxides emissions. The mathematical model of nitrogen oxide formation relies on the application of simplified kinetic equations describing the formation of nitrogen oxides at so-called equivalent temperature. It is a semi-empirical model that comes out of experimental knowledge. An important role played by the burner design itself has been emphasized and therefore an important supplementary parameter of the model is the characteristic of the burner design. It has been established that there was a good agreement between experimental data and those calculated by the application of the model to various conditions marked out by different combustion parameters in the combustion chamber. The results obtained by application of the model respect the influence of parameters validated by industrial practice that control the formation of nitrogen oxides in the course of fuel combustion. Such parameters-first of all-tare the temperature in the combustion chamber and the concentration of the substances taking part in the reaction. By application of the model, it is possible to assess the consequence of, for example the surplus of combustion air, the increase of temperature of combustion air, the supply of inert gas, etc. on the nitrogen oxides emissions of the operating burner under evaluation. Efficient combining of experience and sophisticated approach together with importance of thus access for an improved design are shown.
Phenolic group in therapeutic drugs can be used for a prodrug modification to overcome various undesirable drug properties that may become pharmacological, pharmaceutical or pharmacokinetic barriers for application. Several strategies have been used in order to overcome the limited bioavailability of phenolic drugs. Classical design represents a nonspecific chemical approach to mask undesirable drug properties, limited bioavailability or chemical instability. Targeted prodrug design represents a new strategy for directed and efficient drug delivery. Particularly, targeting the prodrug to specific enzyme or specific membrane transporter has potential as selective drug delivery system mainly in cancer therapy. The article brings examples of ester, sulphate, carbamate, carbonate, phosphate and ether prodrugs as well as the limitations of these prodrug strategies. Some specific enzyme targets are also presented.
- MeSH
- biologická dostupnost MeSH
- fenoly chemie MeSH
- léčivé přípravky aplikace a dávkování metabolismus MeSH
- lékové transportní systémy * MeSH
- lidé MeSH
- nádory farmakoterapie patofyziologie MeSH
- prekurzory léčiv MeSH
- protinádorové látky aplikace a dávkování farmakokinetika farmakologie MeSH
- racionální návrh léčiv * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- fenoly MeSH
- léčivé přípravky MeSH
- prekurzory léčiv MeSH
- protinádorové látky MeSH
Trends towards portable analytical instrumentation of the last decades have not been equally reflected in developments of portable liquid chromatography (LC) instrumentation for rapid on-site measurements. A miniaturised medium pressure capillary LC (MPLC) system with gradient elution capability has been designed based on a flexible modular microfluidic system using primarily off-the-shelf low cost components to ensure wide accessibility to other analysts. The microfluidic platform was assembled on a breadboard and contained microsyringe pumps and switch valves, complemented with an injection valve and on-capillary detectors, all controlled by a PC. Four miniaturised microsyringe pumps, with 5, 20 and 100 μL syringe volume options, formed the basis of the pumping system. Two pairs of pumps were used for each mobile phase to create gradient elution capability. The two microsyringe pumps in each pairs were linked by two electrically operated microfluidic switching valves and both pairs of pumps were connected through a zero void volume cross-connector, thus providing a low hold-up volume for gradient formation. Sample was injected by a 20 nL nano-LC sampling valve, directly connected to a 18 cm long 100 μm i.d. Chromolith CapRod RP-18 monolithic capillary column. On-capillary LED-based UV-vis photometric detection was conducted through a piece of equal diameter fused silica capillary connected after the column. The performance of the portable LC system was evaluated theoretically and experimentally, including the maximum operating pressure, gradient mixing performance, and the performance of the detectors. The 5 μL microsyringe pump offered the best performance, with typical maximum operating pressures up to 11.4 ± 0.4 MPa (water) and gradient pumping repeatability of between 4 and 9% for gradients between 0.10% s(-1) and 0.33% s(-1). Test analytes of charged and uncharged dyes and pharmaceuticals of varying hydrophobicity showed typical RSD values of 0.7-1.4% and 3.3-4.8% in isocratic mode and 1.2-4.6% and 3.2-6.4% in gradient mode, respectively for retention time and peak area repeatability.
- Klíčová slova
- Capillary liquid chromatography, Light emitting diode photometric on-capillary detection, Microfluidics, Off-the-shelf components, Open platform design, Portable liquid chromatography,
- MeSH
- barvicí látky analýza MeSH
- chromatografie kapalinová přístrojové vybavení MeSH
- design vybavení * MeSH
- léčivé přípravky analýza MeSH
- mikrofluidní analytické techniky přístrojové vybavení MeSH
- tlak * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- barvicí látky MeSH
- léčivé přípravky MeSH
Soft glucocorticoids are compounds that are biotransformed to inactive and non-toxic metabolites and have fewer side effects than traditional glucocorticoids. A new class of 17β-carboxamide steroids has been recently introduced by our group. In this study, local anti-inflammatory activity of these derivatives was evaluated by use of the croton oil-induced ear edema test. Glucocorticoids with the highest maximal edema inhibition (MEI) were pointed out, and the systemic side effects of those with the lowest EC50 values were significantly lower in comparison to dexamethasone. A 3D-QSAR model was created and employed for the design of 27 compounds. By use of the sequential combination of ligand-based and structure-based virtual screening, three compounds were selected from the ChEMBL library and used as a starting point for the design of 15 derivatives. Molecular docking analysis of the designed derivatives with the highest predicted MEI and relative glucocorticoid receptor binding affinity (20, 22, 24-1, 25-1, 27, VS7, VS13, and VS14) confirmed the presence of interactions with the glucocorticoid receptor that are important for the activity.
- Klíčová slova
- Anti-inflammatory activity, QSAR, Rational drug design,
- MeSH
- antiflogistika škodlivé účinky chemie farmakologie MeSH
- design s pomocí počítače * MeSH
- edém chemicky indukované farmakoterapie MeSH
- glukokortikoidy škodlivé účinky chemie farmakologie MeSH
- krotonový olej MeSH
- krysa rodu Rattus MeSH
- kvantitativní vztahy mezi strukturou a aktivitou MeSH
- molekulární konformace MeSH
- nemoci ucha chemicky indukované farmakoterapie MeSH
- potkani Wistar MeSH
- racionální návrh léčiv MeSH
- simulace molekulového dockingu MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antiflogistika MeSH
- glukokortikoidy MeSH
- krotonový olej MeSH
Many enzymes contain tunnels and gates that are essential to their function. Gates reversibly switch between open and closed conformations and thereby control the traffic of small molecules-substrates, products, ions, and solvent molecules-into and out of the enzyme's structure via molecular tunnels. Many transient tunnels and gates undoubtedly remain to be identified, and their functional roles and utility as potential drug targets have received comparatively little attention. Here, we describe a set of general concepts relating to the structural properties, function, and classification of these interesting structural features. In addition, we highlight the potential of enzyme tunnels and gates as targets for the binding of small molecules. The different types of binding that are possible and the potential pharmacological benefits of such targeting are discussed. Twelve examples of ligands bound to the tunnels and/or gates of clinically relevant enzymes are used to illustrate the different binding modes and to explain some new strategies for drug design. Such strategies could potentially help to overcome some of the problems facing medicinal chemists and lead to the discovery of more effective drugs.
- Klíčová slova
- drug binding, drug design, protein gates, protein tunnels, selectivity, specificity,
- MeSH
- cílená molekulární terapie * MeSH
- enzymy metabolismus MeSH
- lidé MeSH
- molekulární modely MeSH
- racionální návrh léčiv MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- enzymy MeSH
