The problem of the long-term proliferation of cells is a seminal one. It has always been a hot subject in biology. In this reach, it try to improve the growth rate of paramecium by ultrasound exposure. To perform the above-mentioned research, the oscillation of the paramecium in response to the ultrasound radiation is simulated using Rayleigh-Plesset¡¦s bubble activation theory. The gas body activation theory is to calculate the resonant frequencies of the paramecium at different stages of its life. In this research, it will study the activation of the paramecium division using the resonant and non-resonant frequency of the ultrasonic exposure. The observing images obtained from a microscopic camera can be made and recorded by a personal computer. The biological effects such as the hatching period, growth rate, etc., can be observed from the images. In the past, the physical measurement such as the counting method is the easiest way to observe the biological effects of ultrasound. However, it is not sufficiently to analyze the quantitative bioeffect of paramecium by taking counts. Therefore, utilizing the biochemical technique to assay the difference of specimen may be a good point of view. In this research, employing BCA (Bicinchoninic Acid) assay to inspect the protein variation attain a brand-new quantitative analysis. The results obtained from this research can be used to develop the related ultrasonic biotechnology. By using the theory, the calculated resonance frequency of the paramecium vacuole is about 0.467~1.27 MHz. The maximum amount of paramecium was observed in 72th hours with 1 MHz ultrasound exposure for 5 minutes. It¡¦s 1.77 times relative to the control.

Abstract Ultrasonic technique is widely used in medical application and food industry; however, much work has focused on harmful biological effects of tissues and cells by ultrasound exposure; only little information is mentioned about the beneficial biological effects of ultrasound. Thus, the objective of this thesis is to observe the beneficial biological activities of Paramecium induced by ultrasound exposure. Since the structure or biophysical will stimulated into the interaction between ultrasound and living matter. When multi-cell creature is exposed by ultrasound, this reaction will lead the biological effect becomes complex. Therefore, a single cell creature is chosen to understand the beneficial biological effects induced by ultrasound exposure. The oscillation of the monad in response to the ultrasound radiation is simulated using Rayleigh-Plesset¡¦s bubble activation theory. The resonance frequency of the unicellular creature is then calculated. The diffuse field theory of Sabine is used to create a uniform sound field for the radiation experiment. The images obtained from a microscope can be analyzed and recorded by a personal computer. The number of cells was counted in the haemacytometer after irradiation. The calculated resonant frequency range of the Paramecium shape is 0.2~0.27 MHz. The relative growth rate of the Paramecium suspensions exposed to ultrasound was about 20% slower than that of unexposed sample. It was found that the phenomenon of inhibition and destruction appeared during irradiation. Also, the growth curve is retarded during the period. The resonance frequency of the Paramecium vacuole is 0.5~1.09 MHz. The maximum relative growth rate was increasing 18% with 1MHz irradiation.

This proposal is about a project to study the biological activities of Artemia caused by ultrasound exposure. Ultrasound is employed clinically, for example, in medical diagnosis as a pulse-echo technique for obtaining information of tissue characteristics. It can also use the high-intensity-ultrasound to destroy the lump and pathogens of human tissues. In the other hand, the ultrasonic experiments of plant or insect tissues that contain gas in intercellular channels irradiate with megahertz frequencies of ultrasound, causing perturbation and destruction in nearby cells. Thus, the ultrasonic biological effect, in general, is destructive. However, ultrasound can be a noninvasive form of mechanical energy propagated in biologic organisms. This fact attracts our attention to identify the biologic mechanisms corresponding to the biological activation of Artemia induced by ultrasound exposure. To perform the above-mentioned research, the oscillation of the Artemia in response to the ultrasound radiation is simulated using Rayleigh-Plesset¡¦s bubble activation theory. The gas body activation theory is to calculate the resonant frequencies of the Artemia at different stages of its life. The calculated resonant frequency range of the Artemia cyst shape and the embryonic cuticle is about 0.222~0.226 MHz and 2.46~4.71 MHz. By using the above mentioned resonance frequency of the Artemia, the maximum relative growth rate was increasing 16%. It was found that the Artemia of activation and increasing the hatching rate appeared during irradiation.

This paper adopts a dual-point measurement technique to predict the resonance frequency and operation modes of a high speed rotor at different operating speed. The effect of balance policy on the operating mode shapes of a rotor has also been investigated. Displacement signals measured at two different points of a rotating shaft are used to estimate the operation mode shapes at the main operating frequency based on the definition of transmissibility function. To verify the feasibility of this technique, the dynamic parameters, i.e. natural frequencies, damping ratio and normal modes of a stationary rotor are measured in advance by applying the traditional frequency response method for comparison. The values of modal assurance criterion (MAC) and mode shape diagrams indicate that both methods are in a good agreement on the normal modes when the system is undamped or lightly damped. However, a significant difference is observed for highly damped modes. The dual-point measurement technique is applicable to investigate the effect of rotating speed on measured operation modes at different speed. Results indicate that the rotating speed may affect the dynamic parameters of a rotating shaft significantly. Furthermore, the dynamic unbalance effect on the response of a rotating shaft has also been studied in this thesis. Results indicate that the position of the unbalance is quite sensitive to the response of a rotating shaft. The sensitivity of unbalance and its position is dependent on the operation mode correspondence to the driving speed. The measured results indicate the dual-point measurement is quite available to study the dynamic responses of a rotating shaft or rotor.

The purpose of this study is to explore the biological effects of ultrasound exposure on growth of Saccharomyces cerevisiae. The result shows the biological effects of ultrasound exposure. The resonance frequencies and a non-resonance frequency were used with different intensities to find the relations between ultrasonic and cell growth. The methods of this study adopted finite element method and Rayleigh-Plesset theory to calculate the resonance frequencies. And then, the study set a diffuse field to exposure the yeast cells. In the experiment, cell growths were analyzed by a 600 nm ultraviolet spectrophotometer measuring the cell mass concentration. The results show that the restrained time under high intensity ultrasonic exposure was longer than low intensity in 0.306 and 11.6625 MHz. However, the restrained effects were the same between high and low irradiation intensity in 2.4079 MHz. By 10 MHz low irradiation intensity, the restrained time was 0.5 hr after sonication. The restrain effects were not obvious under low and high irradiation intensity in 16.124 MHz.

Milhões de pessoas em todo o mundo ainda não usufruem dos benefícios da osseointegração. O tratamento reabilitador oral com prótese total sobre implantes tem sido cada vez mais adotado pelos especialistas na área de reabilitação oral. Esta é uma alternativa para a obtenção de retenção e estabilidade em tratamentos com próteses totais convencionais, acredita-se que dois implantes são suficientes para reter uma overdenture satisfatoriamente. O objetivo deste estudo foi avaliar dezesseis pacientes, após a instalação de overdenture inferior, por meio da atividade eletromiográfica dos músculos masseteres e temporais, da força de mordida molar e incisiva máxima e da análise da frequência de ressonância da estabilidade inicial e tardia dos implantes utilizados na retenção das overdenture, sob carga imediata. Para estas análises foram utilizados eletromiógrafo Myosystem - Br1; o dinamômetro modelo IDDK Kratos e o aparelho Osstell. A análise estatística foi executada utilizando o teste de medidas repetidas (SPSS 12.0). Verificou-se diminuição da atividade eletromiográfica no repouso, lateralidades e protusão mandibular, aumento da força de mordida molar e incisiva máxima e aumento dos quocientes de estabilidade dos implantes após quinze meses do tratamento reabilitador. Todos os pacientes relataram melhora significativa em todos os aspectos funcionais e estético do sistema estomatognático. Concluiu-se que o uso de overdenture sobre dois implantes inferiores deve-se tornar o tratamento de escolha para indivíduos desdentados inferiores. / Millions of people around the world do not have access to the osseointegration benefits. Treatments involving oral rehabilitation with overdentures have been widely used by specialists in oral medicine field. This is an alternative therapy for retention and stability achievement in total prostheses with conventional treatments, and two implants are enough to establish an overdenture satisfactorily. The objective of this study was to evaluate sixteen patients after inferior overdenture positioning using the electromyographic activity of masseter and temporal muscles to analyze the following parameters: molar and incisive biting strength, resonance frequency of the initial and later implants stability to retain an overdenture under immediate load. For these tests, it was used the Myosystem - BR1 electromyograph; the IDDK Kratos dynamometer and Osstell apparatus. Statistical analysis was performed using the repeated measures test (SPSS 12.0). It was observed a decrease in electromyographic activity during the rest, lateral and mandibular protrusion; increase of the maximal molar and incisive bite strength, and increase of the stability ratios for implants after fifteen months with rehabilitation treatment. All patients reported significant improvement in all functional and aesthetic aspects of the stomatognathic system. It was concluded that the use of inferior overdenture with two implants should become the selected treatment for total mandibular edentulous patients.

Thesis advisor: Michael Graf / The purpose of this dissertation was to investigate the temporal limit on the ability to measure temperature changes using magnetic resonance imaging (MRI). The limit was examined in experiments using a variety of imaging techniques for MRI-based temperature measurements. We applied these methods for monitoring temperature changes in focused ultrasound (FUS) heating experiments. FUS is an attractive alternative to surgical resection due to its noninvasive character. FUS treatments have been successfully conducted in several clinical applications. MRI and MR thermometry is a natural choice for the guidance of FUS surgeries, given its ability to visualize, monitor, and evaluate the success of treatments. MR thermometry, however, can be a very challenging application, as good resolution is often needed along spatial, temporal as well as temperature axes. These three quantities are strictly related to each other, and normally it is theoretically impossible to simultaneously achieve high resolutions for all axes. In this dissertation, techniques were developed to achieve this at cost of some reduction in spatial coverage. Given that the heated foci produced during thermal therapies are typically much smaller than the anatomy being imaged, much of the imaged field-of-view is not actually being heated and may not require temperature monitoring. By sacrificing some of the in-plane spatial coverage outside the region-of-interest (ROI), significant gains can be obtained in terms of temporal resolution. In the extreme, an ROI can be chosen to be a narrow pencil-like column, and a sampling time for temperature imaging is possible with a temporal resolution of a few milliseconds. MRI-based thermal imaging, which maps temperature-induced changes in the proton resonance frequency, was implemented in two projects. In the first project, three previously described, fast MR imaging techniques were combined in a hybrid method to significantly speed up acquisition compared to the conventional thermometry. Acceleration factors up to 24-fold were obtained, and a temporal resolution as high as 320 milliseconds was achieved. The method was tested in a gel phantom and in bovine muscle samples in FUS heating experiments. The robustness of the hybrid method with respect to the cancellation of the fat signal, which causes temperature errors, and the incorporation of the method into an ultrafast, three dimensional sequence were also investigated. In the second project, a novel MR spectroscopic sequence was investigated for ultrafast one-dimension thermometry. Temperature monitoring was examined during FUS sonications in a gel phantom, SNR performance was evaluated in vivo in a rabbit brain, and feasibility was tested in a human heart. It was shown capable in a FUS heating experiment in a gel phantom of increasing temporal resolution to as high as 53 milliseconds in a three Tesla MRI. The temporal resolution achieved is an order of magnitude faster than any other rapid MR thermometry sequences reported. With this one-dimensional approach, a short sampling time as low as 3.6 milliseconds was theoretically achievable. However, given the SNR that could be achieved and the limited heating induced by FUS in the gel phantom in a few milliseconds, any temperature changes in such a short period were obscured by noise. We have analyzed the conditions whereby a temporal resolution of a few-milliseconds could be obtained. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Milhões de pessoas em todo o mundo ainda não usufruem dos benefícios da osseointegração. O tratamento reabilitador oral com prótese total sobre implantes tem sido cada vez mais adotado pelos especialistas na área de reabilitação oral. Esta é uma alternativa para a obtenção de retenção e estabilidade em tratamentos com próteses totais convencionais, acredita-se que dois implantes são suficientes para reter uma overdenture satisfatoriamente. O objetivo deste estudo foi avaliar dezesseis pacientes, após a instalação de overdenture inferior, por meio da atividade eletromiográfica dos músculos masseteres e temporais, da força de mordida molar e incisiva máxima e da análise da frequência de ressonância da estabilidade inicial e tardia dos implantes utilizados na retenção das overdenture, sob carga imediata. Para estas análises foram utilizados eletromiógrafo Myosystem - Br1; o dinamômetro modelo IDDK Kratos e o aparelho Osstell. A análise estatística foi executada utilizando o teste de medidas repetidas (SPSS 12.0). Verificou-se diminuição da atividade eletromiográfica no repouso, lateralidades e protusão mandibular, aumento da força de mordida molar e incisiva máxima e aumento dos quocientes de estabilidade dos implantes após quinze meses do tratamento reabilitador. Todos os pacientes relataram melhora significativa em todos os aspectos funcionais e estético do sistema estomatognático. Concluiu-se que o uso de overdenture sobre dois implantes inferiores deve-se tornar o tratamento de escolha para indivíduos desdentados inferiores. / Millions of people around the world do not have access to the osseointegration benefits. Treatments involving oral rehabilitation with overdentures have been widely used by specialists in oral medicine field. This is an alternative therapy for retention and stability achievement in total prostheses with conventional treatments, and two implants are enough to establish an overdenture satisfactorily. The objective of this study was to evaluate sixteen patients after inferior overdenture positioning using the electromyographic activity of masseter and temporal muscles to analyze the following parameters: molar and incisive biting strength, resonance frequency of the initial and later implants stability to retain an overdenture under immediate load. For these tests, it was used the Myosystem - BR1 electromyograph; the IDDK Kratos dynamometer and Osstell apparatus. Statistical analysis was performed using the repeated measures test (SPSS 12.0). It was observed a decrease in electromyographic activity during the rest, lateral and mandibular protrusion; increase of the maximal molar and incisive bite strength, and increase of the stability ratios for implants after fifteen months with rehabilitation treatment. All patients reported significant improvement in all functional and aesthetic aspects of the stomatognathic system. It was concluded that the use of inferior overdenture with two implants should become the selected treatment for total mandibular edentulous patients.

In recent years, due to advances in semiconductor technology and mature integrated circuit design, complex signal processing equipment is beginning to be replaced by the integrated circuit. This paper presents an integrated circuit programmable frequency generator for open-loop resonator application and its evaluation. It can eventually replace the conventional discrete component system and be used to find the resonance frequency shift for the readout of micro-balances or similar devices. The oscillator provides an analog tuning input to set the coarse center frequency and bit resolution, and uses a digital input to control the frequency sweep. Calculating the resonance frequency difference between the active balance and a passive reference can mitigate some environmental effects on the resonator (e.g. temperature). The generator circuit is designed using Synopsys¡¦ HSPICE and Cadence's Spectre to perform circuit simulation. The circuit is implemented by Taiwan Semiconductor Manufacturing Company in 0.35 £gm 2-poly 4-metal CMOS process technology. The potential detection precision of a micro-balance using the forward generator is assessed by connecting test chips to an evaluation PCB with commercial piezo crystals providing a known resonance frequency for testing. National Instruments¡¦ LABVIEW is used to record the data output, and MATLAB to analyze the results. A minimum detection accuracy of 1 kHz is demonstrated with this setup.

No description available.