Книги з теми "High frequency resonance method"

Cystic echinococcosis (CE)\cystic hydatid disease is one of the most widespread and important global helminth zoonoses. The parasite Echinococcus granulosus is maintained in a wide spectrum of intermediate hosts, including sheep, goats, camels, cattle, pigs and equines. A number of wild intermediate hosts occur, including cervids in the northern part of the North American continent and Eurasia, marsupials in Australia and wild herbivores in East and southern Africa. The application of a range of molecular techniques to the characterization of the parasite has confirmed the existence of mostly host-adapted strains and genotypes of the parasite and several new species have been proposed. The ubiquitous domestic dog serves as the most important definitive host for the transmission of the parasite throughout its wide geographical range.A wide range of diagnostic techniques, including necropsy, arecoline purgation, coproantigen ELISA and DNA based tests are available for detecting E. granulosus infection in the definitive host. In intermediate animal hosts, diagnosis at post mortem still remains the most reliable option. In humans, imaging techniques including ultrasound, nuclear magnetic resonance (NMR) or computer aided tomography (CAT-scan provide not only a method of diagnosis but also reveal important clinical information on the location, condition, number and size of the hydatid cysts in man. Of these ultrasound is the most widely used diagnostic technique and is the only imaging technique for screening of populations in rural areas, where the disease is most common. A classification system has been developed which can be used to assess the likely development of a cyst and hence guide the clinician in treatment options for the patient. Treatment relies on surgery and/or percutaneous interventions, especially ‘Puncture, Aspiration, Injection, Re-aspiration’ (PAIR) and/or antiparasitic treatment with albendazole (and alternatively mebendazole).CE is largely a preventable disease. Successful elimination programmes have focused on frequent periodic treatments of dogs with anthelmintics and the control of slaughter of domestic livestock. In many regions elimination or even control remains a problem as the parasite is endemic over vast areas of low income countries where there may be limited resources for control. In some areas, such as former communist administered countries, the parasite is resurgent. New tools are becoming available to control the parasite, including a highly effective vaccine in sheep which prevents the infection in sheep and breaks the transmission cycle. In addition cost effective methods are being developed which may be appropriate in low income countries where financial resources are not available for intensive control programmes that have been successful in high income countries.

This chapter summarizes the variety of ways in which ureteric stones can present together with non-radiological and radiological diagnostic tests used to identify them. Ureteric stones classically present with sudden onset, severe loin pain with or without radiation to the groin, testis, or labia majora. The urgent desire to pass urine, combined with increased urinary frequency and the passage of small voided volumes of urine is suggestive of a vesicoureteric junction stone. Haematuria as a presenting symptom of a ureteric stone is rare. Magnetic resonance (MR) urography is an accurate imaging test for identifying ureteric stones. However, at the present time, cost, restricted availability and limited experience in interpretation of the images by radiologists and urologists limit its usefulness as a routine diagnostic method of imaging in cases of acute flank pain.

This chapter, found in the bone, joint, and extremity pain section of the book, provides a succinct synopsis of a key study examining the frequency of incidental findings on knee magnetic resonance imaging. This summary outlines the study methodology and design, major results, limitations and criticisms, related studies and additional information, and clinical implications. Incidental meniscal damage on MRI was shown to be common in the general population, especially among the elderly, and is not necessarily attributable to patients’ knee symptoms. Authors advise those interpreting MRI reports and planning interventions that there is a high prevalence of incidental tears even among those without knee symptoms. In addition to outlining the most salient features of the study, a clinical vignette and imaging example are included in order to provide relevant clinical context.

The ultimate importance of rotor position and speed information in permanent magnet synchronous (PMS) machines control, and the industry interest to the rotor and speed sensorless systems as a cost-saving and practical alternative to the motor control with mechanical sensors are emphasized. Major position and speed estimation schemes are then presented in detail. These are the: back electromotive force (EMF)-based method; flux linkage method; hypothesis rotor position method; saliency-based method, including high frequency signal injection and inverter switching harmonics schemes; and finally, the observer-based method, including state observer and extended Kalman filter-based schemes. Each scheme was discussed by presenting the corresponding fundamental principles, followed by the appropriate motor model, estimation procedure, and the implementation. Demanding criteria such as accuracy, robustness, swiftness, and capability of working over the entire range of motor operation are discussed with each method.

This chapter, found in the abdominal and pelvic pain section of the book, provides a succinct synopsis of a key study examining the use of ultrasound and magnetic resonance fusion imaging-guided biopsy for diagnosing prostate cancer. This summary outlines the study methodology and design, major results, limitations and criticisms, related studies and additional information, and clinical implications. Researchers found that this method of biopsy among men with suspected prostate cancer, compared to standard extended-sextant ultrasound-guided biopsy, is associated with higher detection of high-risk prostate cancer and lower detection of low-risk prostate cancer. In addition, targeted biopsy may significantly shift the distribution of risk in men newly diagnosed with prostate cancer toward more high-risk disease. In addition to outlining the most salient features of the study, a clinical vignette and imaging example are included in order to provide relevant clinical context.

Motivated by the theory of turbulence in fluids, the physicist and chemist Lars Onsager conjectured in 1949 that weak solutions to the incompressible Euler equations might fail to conserve energy if their spatial regularity was below 1/3-Hölder. This book uses the method of convex integration to achieve the best-known results regarding nonuniqueness of solutions and Onsager's conjecture. Focusing on the intuition behind the method, the ideas introduced now play a pivotal role in the ongoing study of weak solutions to fluid dynamics equations. The construction itself—an intricate algorithm with hidden symmetries—mixes together transport equations, algebra, the method of nonstationary phase, underdetermined partial differential equations (PDEs), and specially designed high-frequency waves built using nonlinear phase functions. The powerful “Main Lemma”—used here to construct nonzero solutions with compact support in time and to prove nonuniqueness of solutions to the initial value problem—has been extended to a broad range of applications that are surveyed in the appendix. Appropriate for students and researchers studying nonlinear PDEs, this book aims to be as robust as possible and pinpoints the main difficulties that presently stand in the way of a full solution to Onsager's conjecture.

The fundamentals and best practices of passive microrheology using dynamic light scattering and diffusing wave spectroscopy are discussed. The principles of light scattering are introduced and applied in both the single and multiple scattering regimes, including derivations of the light and field autocorrelation functions. Applications to high-frequency microrheology and polymer dynamics are presented, including inertial corrections. Methods to treat gels and other non-ergodic samples, including multi-speckle and optical mixing designs are discussed. Dynamic light scattering (DLS) is a well established method for measuring the motion of colloids, proteins and macromolecules. Light scattering has several advantages for microrheology, especially given the availability of commercial instruments, the relatively large sample volumes that average over many probes, and the sensitivity of the measurement to small particle displacements, which can extend the range of length and timescales probed beyond those typically accessed by the methods of multiple particle tracking and bulk rheology.