Massa Products (United States)

BackgroundThis prospective registry assessed the safety and efficacy of paclitaxel coated balloon (PCB) angioplasty for small vessel coronary artery disease in Europe and Asia with the intention to treat lesions without additional stenting. The use of PCBs in small vessels seems to be associated with favourable outcomes; however, prospective data for the use of PCBs without stenting are limited.MethodsThe SeQuent Please Small Vessel ‘PCB only’ Registry was an international, prospective, multicentre registry enrolling patients with de novo lesions of small reference diameters (≥2.0 mm, ≤2.75 mm). The primary end point was clinically driven target lesion revascularisation (TLR) at 9 months. Secondary end points were acute technical success, in-hospital outcomes, 9-month major adverse cardiac events (MACE) (death, myocardial infarction, or TLR), and the occurrence of definite lesion and vessel thrombosis.ResultsA total of 479 patients (66.1±10.9 years, 36.7% diabetics) were enrolled, 105 (23.5%) with an acute coronary syndrome, 41 (9.2%) with ST elevation myocardial infarction (STEMI), and 60 (14.8%) with non-STEMI. The initial procedural success rate was 99.0%; 27 patients (6%) needed additional bare metal stent implantation. TLR at 9.4±1.7 months occurred in 14 patients (3.6%), while three patients (0.6%) had vessel thrombosis in non-target lesions. There was no cardiac death or coronary artery bypass graft surgery.ConclusionsTo date, this is the largest prospective study with PCBs in small vessel de novo lesions in unselected patients. Rates of TLR and MACE were low, suggesting the use of PCBs may be an attractive alternative treatment option to drug eluting stents in small vessels.

O objetivo deste estudo foi avaliar a contaminação de 24 HPAs em sedimentos superficiais, em zonas de infra e mesolitoral, identificar as possíveis fontes desses compostos e avaliar os impactos causados na zona costeira da Baía de Todos os Santos, Bahia - Brasil. As análises foram realizadas em um cromatógrafo a gás, acoplado a um espectrômetro de massas (CG-MS). A maior concentração do total de HPAs encontrada foi na estação M14 – Saubara (7221,3 ng/g massa seca), e a menor concentração foi verificada na estação M07 – Ilha de Cajaiba (48,6 ng/g massa seca). A distribuição dos HPAs dentro da BTS é governada não só por suas fontes geradoras mais por condições oceanográficas como o fluxo das correntes existentes dentro da BTS. Os resultados encontrados pelas razões moleculares e a análise dos componentes principais (PCA) mostram que as localidades estudadas na BTS apresentam uma predominância de compostos originados através de processos de combustão (pirolíticos), no entanto, a razão Ant/178 demonstrou uma forte contribuição de HPAs de origem petrogênica, provavelmente em conseqüência das atividades de produção, transporte e refino de petróleo na BTS. Os sedimentos da BTS apresentam um grau de contaminação que vai de baixo a alto o que pode comprometer a sua qualidade toxicológica. Algumas estações apresentam concentrações de HPAs individuais acima do Probable Effect Level (PEL), sugerindo desta forma que estes sedimentos podem causar efeitos adversos em organismos.

A unique low-frequency (900 Hz) Class IV flextensional transducer which produces enhanced far-field pressure on one side and canceled far-field pressure on the other side has been developed. The transducer radiating surface consists of an elliptical aluminum shell and a piezoelectric stack along its major axis with two active sections and one inactive section. The directionality is achieved by exciting the shell into an omnidirectional and dipole operation by driving the ceramic stack into both extensional and bending modes. Both measurements and modeling on this device show a front to back pressure ratio of more than 25 dB, producing cardioid type radiation patterns over an octave band. The measured mechanical Q, coupling coefficient, and electroacoustic efficiency were found to be approximately 8%, 0.25%, and 80%, respectively, and the transducer produced a source level of 215 dB re: 1 μPa/m. Six of these transducers were placed in a closely packed line array. The array successfully produced narrow directional sound beams with a front to back ratio greater than 25 dB and a source level of 225 dB re: 1 μPa/m. [Work supported, in part, through a U. S. Navy SBIR contract.]

To evaluate the antihypertensive effect of nifedipine gastrointestinal therapeutic system and retard in terms of trough:peak ratio efficacy. According to a double-blind, randomized, crossover design, 58 patients with mild-to-moderate essential hypertension, after 1 month placebo washout, received 30 mg/day nifedipine gastrointestinal therapeutic system, 20 mg nifedipine retard twice a day and the corresponding placebos for 1 month. At the end of each treatment period, blood pressure was measured by using a mercury sphygmomanometer at trough and 1, 2, 3 and 4 h after the last dosing. The peak effect was identified as the maximum decrement induced by the three randomized treatments with respect to the value at the end of the placebo washout period during the 4 h interval. The trough:peak ratios of systolic and diastolic blood pressure were calculated as group ratios and individual ratios from decrements induced by nifedipine gastrointestinal therapeutic system and retard, corrected for those induced by randomized placebo. Patients were defined as responders to each randomized treatment if their diastolic blood pressure at trough time was reduced by at least 10 mmHg relative to that at the corresponding time at the end of placebo washout. Nifedipine gastrointestinal therapeutic system and retard significantly reduced blood pressure to a similar extent both at trough and at peak. Systolic and diastolic group trough:peak ratios in responders to nifedipine gastrointestinal therapeutic system (n = 41) were 0.80 and 0.88, respectively, and those in responders to nifedipine retard (n = 30) 0.84 and 0.93, respectively. The percentage of patients with trough:peak ratios > 0.50 was > 80% (systolic trough:peak ratios) and above 90% (diastolic trough: peak ratios) for both nifedipine formulations. Our data show that 30 mg/day nifedipine gastrointestinal therapeutic system and 20 mg nifedipine retard twice a day have a favourable trough:peak ratios efficacy when given as monotherapy to essential hypertensive patients.

A unidirectional magnetostrictive/piezoelectric hybrid transducer was constructed that produced enhanced motion at one end and canceled motion at the other end. In the simplest form the transducer consists of a quarter wavelength section of piezoelectric material joined to a quarter wavelength section of Terfenol-D rare earth magnetostrictive material. A 3-kHz experimental hybrid transducer with a total length of approximately 18 in. (0.46 m) was constructed with a small central mass and two small identical end piston masses. Measurements and calculations on this device showed an average front-to-back ratio of approximately 17 dB.

During this brief presentation, time will be turned back a half-century to permit some personal recollections of early experiences as we explored the new frontiers in electroacoustics. The availability of the vacuum tube for the amplification of weak signals made possible the practical application of a variety of wide-range low-sensitivity transduction techniques for the generation and reproduction of sound. Our training in electrical engineering provided an understanding of electrical measurements and design techniques that we could adapt for new specialized uses during our early stages of acoustic measurements and electroacoustic research. The demands of the new talking picture industry for improved electrical recording and reproduction of sound helped finance the costs of electroacoustic research which resulted in rapid progress in the sound reproduction and recording industry during the early 1930s. In less than a decade the reproduction of sound was transformed from the primitive limited frequency range of the mechanical phonograph to the high quality electrical recording and reproduction made possible by the rapid advances in electroacoustic engineering.

A new family of ultrasonic transducers will be described that are especially useful as position sensing probes in many robotic applications. Low-frequency (20–40 kHz) transducers using small exponential horns achieve efficiencies in the order of 50%, and are used for long-range (50-ft) distance measuring. High-frequency (200- to 500-kHz) transducers utilizing planar mode vibrating ceramic discs in combination with quarter-wavelength acoustic waveguides eliminate secondary lobes and are particularly useful for making shorter range measurements and for achieving very high resolution (± 0.001 in.) at close ranges. The new transducers provide a wide variety of beam angles from virtually omnidirectional to 5° conical. The transducer designs to be described operate on either the fundamental or on a controlled overtone mode of the vibratile element, depending on the frequency region of operation required. Special sensing modules will be shown which include the interface circuitry permitting simple control of the ultrasonic sensing probe by logic signal commands produced by the robot's computer.

Journal Article Random Walks and the Theory of the Optimal International Reserves Get access Koichi Hamada, Koichi Hamada University of Tokyo Search for other works by this author on: Oxford Academic Google Scholar Kazuo Ueda Kazuo Ueda Massa Search for other works by this author on: Oxford Academic Google Scholar The Economic Journal, Volume 87, Issue 348, 1 December 1977, Pages 722–742, https://doi.org/10.2307/2231365 Published: 01 December 1977