Abstract Ciprofloxacin was incorporated to plain bioresorbable self-reinforced polylactide/glycolyde 80/20 screws and tacks (ciprofloxacin releasing SR-PLGA). These implants were compared to otherwise similar conventional fixation devices. The effect of the ciprofloxacin addition on the pull-out force of screws and tacks was evaluated in human cadaver cranial bones. SR-PLGA tacks applied to cranial bone with a special applicator gun had a similar holding power as screws. Addition of the antibiotic compromised the strength of the screws so that ciprofloxacin-containing PLGA screws had lower pull-out strength than corresponding plain PLGA screws. Scanning electron microscopy showed that the fibrillar strip-like microstructure of plain SR-PLGA screws turned into a coarse uni-axial platelet-like pattern as a result of ciprofloxacin addition. It is concluded that this type of 4 mm long and 1.5 mm diameter ciprofloxacin-containing screws can only be used in non-load-bearing or slightly load-bearing applications. Tissue reactions elicited by plain bioresorbable self-reinforced polylactide/glycolide (SR-PLGA) 80/20 screws were compared to similar but ciprofloxacin-releasing SR-PLGA fixation devices in rabbit cranial bone. Plain and ciprofloxacin-PLGA 80/20 screws elicited only mild inflammatory reactions upon implantation in rabbit cranial bone, but they did not interfere with osteoblast activity in up to 72 week long follow-up. Release of the antibiotic from ciprofloxacin-PLGA screws was gradual and the drug concentration in bone tissues was still higher at 8 weeks than the minimal inhibitory concentration (MIC) of ciprofloxacin for S. aureus (0.1–1.0 μg/g). Ciprofloxacin-releasing SR-PLGA screws can find clinical usage in the prevention of implant-related infections in osteofixation in craniomaxillofacial bones in non-load-bearing or slightly load-bearing applications. Larger 6 mm long and 2 mm diameter ciprofloxacin-releasing tacks had a similar holding power to cranial bone as conventional tacks. Tacks can be recommended for clinical use as the application procedure saves time and costs.

The aim of this thesis was to characterize lean production and kanban method in TRW Carr, s.r.o., Stará Boleslav. The thesis describes current firm situation with focus on kanban method. The another aim was to propose possible improvements. In the thesis are proposed solutions, successfully implemented in different plants. The thesis also include totaly new proposals, which can be implemented only in concrete plant. The last aim of this thesis was to find more effective system and implement new trends, if possible.

The topic of the master thesis is an analysis of the attitude of future graduates towards self-employment. The aim of the thesis is to find out, within the push-pull theory, which factors currently influence graduates in decision-making whether to be employed or to start their own business and whether their attitude has changed due to the situation in society associated with the COVID-19 pandemic. The research will be conducted by a questionnaire survey. The result of the thesis will be a comparison of motives for decision-making between employment and entrepreneurship before and during the pandemic crisis. Based on the research results, solutions for increasing motivation of future graduates to become entrepreneurs and suggestions for improving strategy of business support organizations to support entrepreneurship among graduates according to their needs will be proposed

This diploma thesis is focused on design of high frequency power amplifiers in UHF band, specifically at 435 MHz. Amplifiers are designed in different classes of operation. The thesis deals with the comparison of main parameters in each class of operation, the most important parameter is effeciency. The amplifying part is unipolar transistor which is working in Single-stage mode. The results were simulated in Advanced Design Systems Software.

We created an analytical reduced-order model (macromodel) for an electrically actuated circular plate with an in-plane residual stress for applications in capacitive micromachined ultrasonic transducers (CMUTs). After establishing the equations governing the plate, we discretized the system by using a Galerkin approach. The distributed-parameter equations were then reduced to a finite system of ordinary-differential equations in time. We solved these equations for the equilibrium states due to a general electric potential and determined the natural frequencies of the axisymmetric modes for the stable deflected position. As expected, the fundamental natural frequency generally decreases as the electric forcing increases, reaching a value of zero at pull-in. However, strain-hardening effects can cause the frequencies to increase with voltage. The macromodel was validated by using data from experiments and simulations performed on silicon-based microelectromechanical systems (MEMS). For example, the pull-in voltages differed by about 1% from values produced by full 3-D MEMS simulations. The macromodel was then used to investigate the response of an electrostatically actuated clamped circular plate to a primary resonance excitation of its first axisymmetric mode. The method of multiple scales was used to derive a semi-analytical expression for the equilibrium amplitude of vibration. The plate was found to always transition from a hardening-type to a softening-type behavior as the DC voltage increases towards pull-in. Because the response of CMUTs is highly influenced by the boundary conditions, an updated reduced-order model was created to account for more realistic boundary conditions. The electrode was still considered to be infinitesimally thin, but the electrode was allowed to have general inner and outer radii. The updated reduced-order model was used to show how sensitive the pull-in voltage is with respect to the boundary conditions. The boundary parameters were extracted by matching the pull-in voltages from the macromodel to those from finite element method (FEM) simulations for CMUTs with varying outer and inner radii. The static behavior of the updated macromodel was validated because the pull-in voltages for the macromodel and FEM simulations were very close to each other and the extracted boundary parameters were physically realistic. A macromodel for CMUTs was then created that includes both the boundary effects and an electrode of finite thickness. Matching conditions ensured the continuity of displacements, slopes, forces, and moments from the composite to the non-composite regime of the CMUT. We attempted to validate this model with results from FEM simulations. In general, the center deflections from the macromodel fell below those from the FEM simulation, especially for relatively high residual stresses, but the first natural frequencies that accompany the deflections were very close to those from the FEM simulations. Furthermore, the forced vibration characteristics also compared well with the macromodel predictions for an experimental case in which the primary resonance curve bends to the right because the CMUT is a hardening-type system. The reduced-order model accounts for geometric nonlinear hardening, residual stresses, and boundary conditions related to the CMUT post, allows for general design variables, and is robust up to the pull-in instability. However, even more general boundary conditions need to be incorporated into the model for it to be a more effective design tool for capacitive micromachined ultrasonic transducers. / Ph. D.

In the absence of treatment following strokes, both humans and model organisms demonstrate partial improvements in motor function. Several endogenous mechanisms, such as cortical reorganization, are hypothesized to cause this spontaneous biological recovery. Reorganization of the motor cortex occurs within a time sensitive period and involves both proximal and distal sites of the intact brain. Despite these advancements, whether the same or different cells are used in the reorganized cortex after stroke remains unknown. In order to identify the motor networks involved in recovery, our lab has begun using the inducible Arc-CreERᵀ²:Rosa-YFPᶠᐟᶠ mice. In conjunction with the bimanual string-pulling task, this inducible model allows for the labelling of active cells throughout stroke recovery; either pre, 2 days post-stroke (dps) and 2 weeks post-stroke (wps). Behavioural deficits on the string-pull task were observed at 2 dps and accompanied by a decrease in active cells in the ipsilesional secondary motor (M2) cortex of stroke mice. By 2 wps, stroke mice had partial recovery of motor function with no differences in active cells in the ipsilesional M2. Interestingly, ~40% of cell in the motor cortex of sham and stroke mice were activated more than once while performing the string-pull task until 2 wps. Deeplabcut kinematic analysis of the string-pull task was also unable to identify differences in motor performance between stroke and sham mice. In addition, irrelevant of stroke injuries, only 60% of cells co-expressed the pan-neuronal marker NeuN after surgeries. Together these findings suggest that 40% of cells are reactivated up to 2 weeks post-stroke during the performance of a motor task, despite the acute decreases in active cells in the ipsilesional M2 of stroke mice. DeepLabCut kinematic results also highlight the need to redefine kinematic outcomes to better assess the full spectrum of stroke deficits.

Many orthopedic conditions in dogs require the placement of bone screws in the proximal tibial metaphysis. Currently, both cortical and cancellous screws are used clinically depending on the surgeon’s preference; however, the ideal screw for use in the proximal tibia has not been determined. Currently, both the manual and power tapping techniques are used during surgical procedures of the proximal tibia in dogs. However, it is unknown if the use of power tapping when placing screws in the canine proximal tibial metaphysis affects screw purchase. Measurement of axial pull-out strength is traditionally used to evaluate and compare the holding power of screws inserted in bone. This study compares the axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous screws inserted using manual and power tapping techniques in the proximal tibial metaphysis

Domestic secondary wood products manufacturers are losing their competitive edge in the global economy. Foreign competition is steadily gaining market-share due to decreased labor costs. While domestic operations can not compete with labor costs available to foreign manufacturers, they may be able to remain competitive through product lead time reduction and on-time delivery to the final customer. Pull based manufacturing is one technique to reduce lead time increase on-time delivery. Value stream mapping was used in this project to evaluate a furniture rough mill located in Virginia to assess the current state, as well as develop 2 future state value streams. The current state evaluation found the system to be yield driven and production was based on a forecast. The lead time for internal nightstand components in the current state was found to be 15.1 hours. Using pull production and supermarket methodology in proposed future states, it was found that the lead time could be reduced to 7.5 hours. Lead times could be reduced by eliminating yield increasing non-value added activities currently in place which not only increase lead time, but also manufacturing waste as defined by lean manufacturing concepts. A cost analysis found that the labor and overhead costs associated with yield increasing activities in the current state outweighed the costs of a decreased yield measurement in the future state. While this project was limited to one rough mill and one product family of a lesser valued wood species it represents what is possible for assisting secondary manufacturers to remain competitive. The once successful traditional yield driven rough mill does not guarantee internal customer satisfaction and in this project is not cost effective. Future research should focus on the implications of the furniture rough mill's inability to meet downstream demand to internal customers. / Master of Science

Peer code reviews play a critical role in maintaining code quality, and GitHub has introduced several new features to assist with the review process. One of these features is suggested changes, which allows for precise code modifications in pull requests to be suggested in review comments. Despite the availability of such helpful features, many pull requests remain unattended due to lower priority. To address this issue, we developed a bot called ``Suggestion Bot" to automatically review the codebase using GitHub's suggested changes functionality. An empirical study was also conducted to compare the effectiveness of this bot with manual reviews. The findings suggest that implementing this bot can expedite response times and improve the quality of pull request comments for pull-based software development projects. In addition to providing automated suggestions, this feature also offers valuable, concise, and targeted feedback. / Master of Science / Code review, often known as peer review, is a process used to ensure the quality of software. Code review is a process in software development that involves one or more individuals examining the source code of a program, either after it has been implemented or during a pause in the development process. The creator of the code cannot be one of the individuals. "Reviewers" refers to the individuals conducting the checking, excluding the author. However, the majority of reviewers won't have the time to examine and validate the peer's code base, so they'll assign it the lowest priority possible. This could cause pull requests to stall out without being reviewed. Therefore, as part of our research, we are creating a bot called SUGGESTION BOT that provides code changes in pull requests. The author can then accept, reject, or alter these ideas as a necessary component of the pull request. Additionally, we compared the effectiveness of our bot with the manual pull request review procedure, which clearly demonstrated that the incorporation of this bot significantly shortened the turnaround time. Besides giving automated recommendations, this functionality also provides useful, brief, and focused feedback.

Studying protein-protein interactions has been vital for understanding how proteins function within the cell, how biological processes are strictly regulated by these interactions, and what molecular mechanisms underlie cellular functions and diseases. Recent biochemical and biophysical studies have provided evidence supporting that G protein-coupled receptors (GPCRs) can and do interact with one another to form dimers or larger oligomeric complexes, which may determine the structure and function of GPCRs, including receptor trafficking, scaffolding and signaling. This may help to understand the physiological roles of GPCRs and mechanisms underlying certain disease pathologies and to provide an alternative approach for drug intervention.<p>Cannabinoid CB1 and dopamine D2 receptors are the most common GPCRs in the brain and exert a mutual regulation in brain functions involved in learning, memory and drug addiction. There is structural and functional evidence supporting the idea that CB1 and D2 receptors physically interact with each other in hippocampal and striatal neurons to modulate their functions. Direct evidence supporting a physical interaction between the CB1 and D2 receptors was obtained from cultured HEK293 cells stably coexpressed with both receptors.<p> This research project was designed to critically test the hypothesis that a specific protein sequence (i.e. motif) in the D2 receptor is responsible for in vitro protein-protein interactions between the CB1 and D2 receptors. To reach this goal, fusion proteins containing various domains and motifs of the CB1 and D2 receptors were prepared and then used first to determine the domains of the CB1 and D2 receptors responsible for in vitro protein-protein interactions between CB1 and D2 receptors, and then to identify the specific motifs in the D2 receptor responsible for in vitro CB1 coupling with the D2 receptors. The major method used in this study is in vitro pull-down assay, which uses a purified and tagged bait protein to generate a specific affinity support that is able to bind and purify a prey protein from a lysate sample. The present study provides the first evidence that CB1 intracellular C-terminal (CB1-CT) and D2 intracellular loop 3 (D2-IL3) can directly interact with each other, and that the specific motifs D2-IL3(Ⅳ1) and D2-IL3(Ⅳ3) in the D2 receptor are likely responsible for their in vitro coupling with the CB1 receptors. <p>The results of the present study are invaluable for future research exploring in vivo protein-protein interaction between the CB1 and D2 receptors in the rat striatum by co-immunoprecipitation. Specifically, future studies will determine whether the identified specific motifs D2-IL3(Ⅳ1) and D2-IL3(Ⅳ3) in the D2 receptor are indeed critical for their in vivo coupling with the CB1 receptors.