BACKGROUND Flutter VRP1, Shaker, and Acapella are devices that combine positive expiratory pressure (PEP) and oscillations. OBJECTIVES To compare the mechanical performance of the Flutter VRP1, Shaker, and Acapella devices. METHODS An experimental platform and a ventilator, used a flow generator at 5, 10, 15, 20, 26, and 32 L/min, were employed at angles of -30°, 0°, and +30° to evaluate Fl...

Substitution of the S4 of Shaw into Shaker alters cooperativity in channel activation by slowing a cooperative transition late in the activation pathway. To determine the amino acids responsible for the functional changes in Shaw S4, we created several mutants by substituting amino acids from Shaw S4 into Shaker. The S4 amino acid sequences of Shaker and Shaw S4 differ at 11 positions. Simultan...

DYNAMIC TESTING REFERENCE ISSUE is recognized as being elastic rather than rigid. This is modeled by treating the coil and table as separate masses connected The performance envelope of an electrodynamic shaker system is strongly influenced by three modes of vibration and the voltage/current capacities of the power amplifier that drives it. Other limiting factors are the designed stroke (displa...

A Hybrid Partitioned Frequency/Time domain adaptive filtering algorithm for vibration shock control is proposed. Due to the complexity of the electrodynamic shaker transfer function, the FIR based model of this transfer function requires thousands of filter weights. The Hybrid Partitioned Frequency/Time domain approach for computing the shaker model and inverse controller model is proposed, suc...

Electrodynamic shakers are utilized in many experimental modal tests and general structural dynamic testing. The physical aspects of shaker, stinger and transducer setup can result in anomalies that are often misunderstood. Many times measurement artifacts related to mounting and dynamic coupling between shaker, stinger and test object can appear, affecting test results. This paper overviews so...

Regulation of synaptic efficacy by nerve terminal excitability has not been extensively studied. We performed genetic and pharmacological dissections for presynaptic actions of K+ channels in Drosophila neuromuscular transmission by using electrophysiological and optical imaging techniques. Current understanding of the roles of the Shab IK channel and its mammalian Kv2 counterparts is relativel...

The members of the voltage-dependent potassium channel family subserve a variety of functions and are expected to have voltage sensors with different sensitivities. The Shaker channel of Drosophila, which underlies a transient potassium current, has a high voltage sensitivity that is conferred by a large gating charge movement, approximately 13 elementary charges. A Shaker subunit's primary vol...

FlaSh-YFP, a fluorescent protein (FP) voltage sensor that is a fusion of the Shaker potassium channel with yellow fluorescent protein (YFP), is primarily expressed in the endoplasmic reticulum (ER) of mammalian cells, possibly due to misfolded monomers. In an effort to improve plasma membrane expression, the FP was split into two non-fluorescent halves. Each half was randomly inserted into Shak...

Local anesthetics bind to ion channels in a state-dependent manner. For noninactivating voltage-gated K channels the binding mainly occurs in the open state, while for voltage-gated inactivating Na channels it is assumed to occur mainly in inactivated states, leading to an allosterically caused increase in the inactivation probability, reflected in a negative shift of the steady-state inactivat...

BACKGROUND Dysphagia is a serious complication of chemoradiotherapy (CRT) in patients with head and neck cancer. Approximately 20% to 30% of patients who have dysphagia require feeding tubes. The purpose of this study was to evaluate the impact of prophylactic swallowing exercises on swallowing function. METHODS Fifty-one patients with advanced oropharyngeal, hypopharyngeal, and laryngeal can...