Photo-polymerization kinetics of a dental resin at a high temporal resolution.

Objectives: This study: 1) aims to measure with high temporal resolution the intrinsic rate of the degree of conversion (DC) of a dental resin-based composite (RBC) photo-cured at two irradiances; 2) aims to determine the transition time at which the DC rate is maximum; 3) used two different irradiances to measure the shift in transition time; 4) aims to compare transition times measured using DC and shrinkage strain.

Methods: Samples (n = 20) 1 mm thick by 10 mm diameter of Filtek One bulk-fill restorative A2 shade (3M Oral Care) were photocured for 20 s with a single emission peak (wavelength centered at 455 nm) light-emitting-diode-based light-curing unit at irradiance levels of 890 mW/cm and 209 mW/cm, and initial sample temperature of T = 23 °C. The DC was measured in real-time using Attenuated Total Reflection (ATR) FTIR spectroscopy with a sampling rate of 13 DC data points per second.

The gridded retarding ion drift sensor for the petitSat cubeSat mission.

The Gridded Retarding Ion Drift Sensor (GRIDS) is a small sensor that will fly on the 6 U petitSat CubeSat. It is designed to measure the three-dimensional plasma drift velocity vector in the Earth's ionosphere. The GRIDS also supplies information about the ion temperature, ion density, and the ratio of light to heavy ions present in the ionospheric plasma.

A configurable ion source for validating spaceflight-based thermal plasma measurement systems.

Thermal ion instruments are valuable for analyzing Earth's upper atmosphere. Prelaunch vacuum chamber testing of such instruments with a thermal ion source is often used to validate the performance of such instruments in a relevant environment, which is a prerequisite for a NASA flight. In this paper, we describe a new ion source that can be used for such tests, compare its performance with simulation results, and present an example of the utility for the source for validating the performance of an instrument.

Exploring determinants of behavioral chronotype in a diurnal-rodent model of human physiology.

Numerous studies conducted with human participants have shown that differences in chronotype, defined as individual patterns of early or late beginning of daily activity, have implications for many biobehavioral processes, such as cognitive performance, mood, impulsivity, academic achievement of college students, and mental health. However, the determinants of individual variation in chronotype have not been investigated. Basic research on circadian rhythms has provided a basis for investigating the causes of chronotype variation, but experimental tests of pertinent hypotheses are difficult to conduct with human subjects.

A neutral wind instrument for nano-satellite platforms.

Here we describe the first neutral wind sensor developed specifically for use on resource limited nano-satellite platforms. The instrument is a next generation redesign of the ram wind sensor flown on the Communications/Navigation Outage Forecasting System satellite for measurements of neutral velocity, temperature, and composition. Results of subsystem tests in vacuum conditions show low-power operation, promising design, and good resolution of measured parameters over the operational pressure and energy ranges expected in the low Earth orbit environment.

Real-time intracochlear imaging of automated cochlear implant insertions in whole decalcified cadaver cochleas using ultrasound.

Objectives: This study aimed to determine the feasibility of combining high-frequency ultrasound imaging, automated insertion, and force sensing to yield more information about cochlear implant insertion dynamics.

Methods: An apparatus was developed combining these aspects along with software to control implant and imaging probe positions. Decalcified unfixed human cochleas were implanted at various speeds, insertion sites, and implant models while imaging near the implant tip throughout insertion and recording force data from the cochlea mounting stage.

Transmission of a novel sonotubometry acoustic click stimulus in healthy and patulous eustachian tube subjects: a retrospective case -control study.

Background: Eustachian tube (ET) dysfunction can be very difficult to diagnose accurately. Our aim is to determine whether a newly developed sonotubometric test using clicks can reliably detect ET opening during swallowing in normal ET subjects, and patulous ET (PET) in subjects with ET dysfunction.

Methods: Sixteen subjects (19 normal ET ears and 6 PET ears) were individually placed in a sound-isolated audiometry booth and subjected to a 1000Hz click train stimulus, played through the nose.

Acoustic Transmission Characteristics of a Eustachian Tube Volitionally Opened in Two Living Subjects.

Objective: To assess the acoustic transmission characteristics of the Eustachian tube (ET) in living subjects in verified patent and closed ET states to facilitate the detection and quantification of ET function using acoustic measures such as sonotubometry.

Patients: The two subjects in this study had no history of ear disease nor previous ear surgery and were capable of volitionally opening and closing their ET.

Interventions: Tympanometry and otologic examinations were used to confirm ET patent and closed states by observing tympanic membrane movement with respiration and by acoustic immitance measurements during forced respiration.

Teacher candidates' mastery of phoneme-grapheme correspondence: massed versus distributed practice in teacher education.

Matching phonemes (speech sounds) to graphemes (letters and letter combinations) is an important aspect of decoding (translating print to speech) and encoding (translating speech to print). Yet, many teacher candidates do not receive explicit training in phoneme-grapheme correspondence. Difficulty with accurate phoneme production and/or lack of understanding of sound-symbol correspondence can make it challenging for teachers to (a) identify student errors on common assessments and (b) serve as a model for students when teaching beginning reading or providing remedial reading instruction.

A versatile retarding potential analyzer for nano-satellite platforms.

The design of the first retarding potential analyzer (RPA) built specifically for use on resource-limited cubesat platforms is described. The size, mass, and power consumption are consistent with the limitations of a nano-satellite, but the performance specifications are commensurate with those of RPAs flown on much larger platforms. The instrument is capable of measuring the ion density, temperature, and the ram component of the ion velocity in the spacecraft reference frame, while also providing estimates of the ion composition.

New Approaches for Controlling Saprolegnia parasitica, the Causal Agent of a Devastating Fish Disease.

Pathogenic oomycetes have the ability to infect a wide range of plant and animal hosts and are responsible for a number of economically important diseases. Saprolegniasis, a disease affecting fish eggs and juvenile fish in hatcheries worldwide, is caused by the pathogenic oomycete Saprolegnia parasitica. This disease presents as greyish-white patches of filamentous mycelium on the body or fins of fish and is associated with tissue damage leading to death of the animal.

Hybrid endovascular repair of thoracic aortic aneurysms by debranching and the creation of landing zone-zero.

Thoracic aortic aneurysms (TAA) have remained a formidable operative challenge. Open surgical techniques have been associated with high rates of morbidity and mortality. Thoracic endovascular aneurysm repair (TEVAR) has produced results equal to or better than the traditional open surgical approach.

Precise instructions determine participants' memory search strategy in judgments of relative order in short lists.

Memory often requires knowledge of the order of events. Previous findings about immediate judgments of relative order in short, subspan lists are variable regarding whether participants' strategy is to search memory in the forward direction, starting from the first list item and progressing toward the end item, or in the backward direction, starting from the end item and progressing toward the start. We asked whether wording of the instructions influences participants' search direction.

Endograft repair of type B aortic dissection with three-year follow-up.

Type B aortic dissections have remained a difficult management problem. Open surgical techniques have had a very high perioperative mortality, and medical management has not produced satisfactory long-term results. Endovascular grafting techniques may provide a favorable alternative therapy.

Teaching medical students pediatric cardiovascular examination by telemedicine.

The aim of this feasibility study was to assess whether medical students can be taught the pediatric examination of the cardiovascular system (CVS) facilitated by telemedicine equipment. The views of the students regarding this new technology were sought in a subsequent questionnaire survey. Seventy-seven (n = 77) medical students attended eight telemedicine sessions that consisted of a lecture, case discussion, and physical examination of a child using an electronic stethoscope.

A new satellite-borne neutral wind instrument for thermospheric diagnostics.

The bulk motion of the neutral gas at altitudes between about 200 and 600 km is an important factor in predicting the onset of plasma instabilities that are known to distort and/or disrupt high frequency radio communications. These neutral winds have historically been quite difficult to measure, especially from a moving spacecraft. A new space science instrument called the ram wind sensor has been developed to measure the component of the neutral gas velocity that lies along the orbit track of a satellite in low Earth orbit.

Primary pulmonary rhabdomyosarcoma: a long-term survivor.

This is a clinical report of a young girl who presented with a large left lung mass, which was found to be alveolar rhabdomyosarcoma, a rare clinical entity. This was successfully treated with surgery, radiation, and chemotherapy. To our knowledge, this is the longest survivor with this disease.

Pulmonary carcinosarcoma.

Pulmonary carcinosarcoma is a rare malignancy, comprising less than 0.3% of all malignant neoplasms of the lung. Since the first report of this tumor by Kika in 1908, approximately 100 cases have been described in the literature.

Giant pulmonary cyst simulating tension pneumothorax.

Giant pulmonary cyst is a rare clinico-pathological entity. It was described as a "windy tumor" by John Floyer in 1726. Since that time, there have been numerous reports on this unique manifestation of emphysema by many authors.

Surgical management of intrathoracic goiter.

Intrathoracic goiter is a rare clinical entity. This goiter can develop slowly and the patient may be asymptomatic for many years. A significant number of these patients, however, may develop various complications as a result of compression of vital structures or malignancy.

Carotid endarterectomy in a community hospital.

Despite the popularity of carotid endarterectomy, considerable debate remains regarding the appropriateness of these procedures. Critics of carotid endarterectomy cite the excessive morbidity and mortality associated with these procedures, particularly when performed in a community hospital setting. A retrospective study of 130 procedures, involving 124 patients within a medium size community hospital setting, was conducted.

Embolic stroke from cardiac papillary fibroelastomas.

We describe two patients with cerebral emboli originating from a cardiac papillary fibroelastoma and compared them with six patients reported in the literature. Surgical excision was curative in both of our patients. The surface topography of the tumor, as visualized by scanning electron microscopy, is described.

Effect of coronary artery revascularization on left and right ventricular ejection fractions during rest and exercise.

We have reported a case of a 55-year-old man who had improvement of both left and right ventricular ejection fractions during rest and exercise after coronary revascularization. Ventricular performance was assessed using radionuclide angiography. Although coronary artery bypass grafting has previously been shown to improve left ventricular function, we believe this is the first report of improved right ventricular function after coronary revascularization.