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At least 469 records · Page 26Linked to original sources
PubMed1997

[Pleomorphic adenoma of the lower turbinates: clinical case and review of literature].

A case of pleomorphic adenoma of the lower turbinate salivary glands is presented. A careful review of the literature has revealed that this is a highly unusual site for such neoplasms. The scarcity of symptoms is underlined as the lesion can long go unrecognized. Moreover, it is pointed out that, since only a small number of cases have thus far been presented for this benign lesion the prognostic factors indicating a clinical evolution to malignancy are as yet unknown. For this reason the authors feel it advisable to perform conservative surgery and carry out a careful follow-up.

Adenoma, Pleomorphic↗
PubMed1979

Blindness secondary to steroid injections into the nasal turbinates.

Two cases of inadvertent intra-arterial injection into the anterior turbinates for treatment of allergic rhinitis resulted in retrograde flow of methylprednisolone acetate in the ophthalmic artery. Both patients demonstrated embolization of the retinal circulation, and one of the choroidal circulation as well. Visual outcome was favorable, although one patient showed a permanent paracentral scotoma. Fundus photographs clearly showed intra-arterial obstruction of arterioles that cleared within several days. Precautions can be taken for the prevention of this complication.

Adult↗
PubMed1994

Turbine flow sensor for volume-flow rate verification in MR.

A turbine flow sensor for MR flow experiments has been evaluated using reference volume-flow rate measurements obtained using an electromagnetic (EM) flow meter measurements and simultaneous phase contrast (PC) MR acquisitions. After calibration, the device was found to have accuracy (compared with the EM flow meter), linearity, and precision of better than +/- 1%, +/- 3.5%, 3.5%, respectively, in constant flow mode (0 to 30 ml s-1). The frequency response of the flow sensor was flat (within +/- 10%) up to 13.9 Hz. Volume-flow rate measurements on constant and simulated physiologic flow waveforms were in close agreement with both the electromagnetic (EM) flow meter and the gated MR PC estimates.

Calibration↗
PubMed1998

Do the bacterial flagellar motor and ATP synthase operate as water turbines?

Despite much progress in the study of the rotary motors ATP synthase (F0F1) and the bacterial flagellar motor, we still cannot answer the most basic and simple question, how the random thermal movement of H+ (or Na+) ions down a pH (or Na+) gradient spins the rotors. I suggest consideration of the possibility that the motors operate like water turbines, i.e., rotation is the outcome of water mini-jets impinging tangentially on the rotors. The vectorial jets are formed when the cations lose part or all of their hydration water upon interacting with a properly positioned site on a protein component which is part of the rotor or is located on a peripheral protein.

Adenosine Triphosphate↗
PubMed1988

A high flow turbine CPAP system.

A continuous high flow CPAP system incorporating a turbine blower is described. The system achieves inspiratory flow rates of 150 l/min or more by means of reticulated gas flow and inspired oxygen fractions of 0.21-0.95. Positive airway pressure is provided by weighted disc valves and a modified aviation-type CPAP face mask provides electronic communication with the patient. The mobility of the system also enables its use as an intermittent physiotherapy aid. Work of breathing of the system, as assessed by total pressure fluctuations is at a minimum.

Acute Disease↗
PubMed1978

Selected isolates of bovine viral diarrhea (BVD) virus propagated on bovine turbinate cells: virus titer and soluble antigen production as factors in immunogenicity of killed BVD virus.

Soluble antigen production in a bovine turbinate cell line by 17 isolates of bovine viral diarrhea virus was studied. We showed that the quantity of soluble antigen produced may vary considerably between isolates. Further, the isolate producing the greatest quantity of soluble antigen produced a higher antibody titer in calves than an isolate producing only half as much soluble antigen.

Animals↗
PubMed1993

Evaluation of five small turbine-type respirometers used in adult anesthesia.

OBJECTIVE: The purpose of this study was to determine the accuracy of five rotating vane or turbine-type respirometers--fdE Magtrak Respiratory Monitor, fdE Haloscale Standard Wright Respirometer, Micro-Medical Pocket Monitor II, and Ohmeda 5400 and 5410 Volume Monitors--which are marketed as suitable for measuring expired gas volume in anesthetized adult patients. METHODS: The devices were tested for accuracy at simulated minute ventilations ranging from 2.4 to 15 L/min with three gas mixtures: air, air saturated with water vapor, and N2O/O2 (70:30). RESULTS: In the usual range for adult minute ventilation during general anesthesia with intermittent positive-pressure ventilation (5-12 L/min), all devices were on average accurate to within 12%. At the lowest minute volume readings (2.4 L/min) all devices except the Pocket Monitor tended to have low readings. No significant differences in readings were introduced by either saturation with water vapor or introduction of 70% N2O, except with ventilation below 4 L/min with both Ohmeda respirometers. CONCLUSIONS: All monitors showed reasonable clinical accuracy in the usual adult minute ventilation range during general anesthesia with intermittent positive-pressure ventilation (> 5 L/min) when used to measure air, water vapor-saturated air, or N2O/O2 mixtures.

Adult↗
PubMed1992

Potential neurotoxin formation in thermally degraded synthetic ester turbine lubricants.

Under extreme conditions of thermal degradation, a potent neurotoxin, trimethylolpropane phosphate (TMPP), may be formed by reaction of tricresyl phosphate (TCP, an anti-wear additive) and trimethylolpropane esters (TMPE) of carboxylic acids that may be contained in turbine engine lubricant formulations. The neurotoxin is only formed at extreme temperatures (350-700 degrees C), which has minimized concern for use of the synthetic lubricants under intended applications; however, since researchers are often not privy to the proprietary composition of such lubricants, extreme caution should be exercised in studies of or applications of synthetic lubricants degraded under extreme conditions.

Animals↗
PubMed1996

Neurotoxin formation from pilot-scale incineration of synthetic ester turbine lubricants with a triaryl phosphate additive.

The high-temperature combustion of synthetic ester turbine engine lubricants has been performed by diluting the lubricant 5, 15, or 25% in diesel fuel and burning the mixture in a pilot-scale boiler facility. The effluent gas from this combustion system was carefully monitored for the formation of a potent neurotoxin, trimethylolpropane phosphate (TMPP). Although TMPP was not detected in the gaseous effluent, elevated levels of the neurotoxin were found in scrapings from the inside of the boiler system. Because of the extreme toxicity of this compound, significant dermal exposure could be a potential risk to incinerator operation and maintenance personnel.

Bridged Bicyclo Compounds, Heterocyclic↗
PubMed2005

Risk of contact allergy and dermatitis at a wind turbine plant using epoxy resin-based plastics.

AIMS: To identify workplace and individual risk factors for occupational contact allergy and dermatitis. METHODS: A cross-sectional study was carried out at an international company producing wind turbine systems in Denmark. A cohort of 724 production workers at four facilities was highly exposed to epoxy resin as well as other chemicals. A screening questionnaire (participation rate 84.7%) was followed by an interview by an occupational physician and a dermatological examination, including patch testing, for a comprehensive list of potential workplace sensitizers. RESULTS: Clinically diagnosed dermatitis was found among 214 workers (35.8%) and contact allergy to materials used in the workplace was found in 66 workers (10.9% of the total population and 20.3% of those who underwent patch testing). Of the 66 workers with a work-related allergy, 40 (60.6%) were allergic to epoxy compounds, 25 (37.9%) to hardeners and ten (15.2%) to other workplace materials, where one person showed an allergy only to these materials. Experiencing contact allergy was related to older age and longer employment in the workplace-however, neither of these risk factors was significant. The main risk factor for current dermatitis was contact allergy to materials used in the workplace, determined by patch testing, OR=5.4 (95% CI 3.9-9.9). Fewer days of absence from work was also related to current dermatitis, OR=2.0 (95% CI 1.2-3.5). CONCLUSIONS: In a cohort of workers with extensive exposure to chemicals related to epoxy-resin systems, contact dermatitis and allergy was prevalent. Older age and longer duration of employment at the workplace were individual risk factors for allergy to workplace materials, whilst work-related allergies and longer duration of employment at the workplace were significant risk factors for current dermatitis.

Adolescent↗
PubMed2005

Bioconversion of waste office paper to gluconic acid in a turbine blade reactor by the filamentous fungus Aspergillus niger.

Gluconic acid production was investigated using an enzymatic hydrolysate of waste office automation paper in a culture of Aspergillus niger. In repeated batch cultures using flasks, saccharified solution medium (SM) did not show any inhibitory effects on gluconic acid production compared to glucose medium (GM). The average gluconic acid yields were 92% (SM) and 80% (GM). In repeated batch cultures using SM in a turbine blade reactor (TBR), the gluconic acid yields were 60% (SM) and 67% (GM) with 80-100 g/l of gluconic acid. When pure oxygen was supplied the production rate increased to four times higher than when supplying air. Remarkable differences in the morphology of A. niger and dry cell weight between SM and GM were observed. The difference in morphology may have caused a reduction of oxygen transfer, resulting in a decrease in gluconic acid production rate in SM.

Air↗
PubMed2003

Real-time analysis system for gas turbine ground test acoustic measurements.

This paper provides an overview of a data system upgrade to the Pratt and Whitney facility designed for making acoustic measurements on aircraft gas turbine engines. A data system upgrade was undertaken because the return-on-investment was determined to be extremely high. That is, the savings on the first test series recovered the cost of the hardware. The commercial system selected for this application utilizes 48 input channels, which allows either 1/3 octave and/or narrow-band analyses to be preformed real-time. A high-speed disk drive allows raw data from all 48 channels to be stored simultaneously while the analyses are being preformed. Results of tests to ensure compliance of the new system with regulations and with existing systems are presented. Test times were reduced from 5 h to 1 h of engine run time per engine configuration by the introduction of this new system. Conservative cost reduction estimates for future acoustic testing are 75% on items related to engine run time and 50% on items related to the overall length of the test.

Journal Article↗
PubMed2004

Tuning of PID controllers for boiler-turbine units.

A simple two-by-two model for a boiler-turbine unit is demonstrated in this paper. The model can capture the essential dynamics of a unit. The design of a coordinated controller is discussed based on this model. A PID control structure is derived, and a tuning procedure is proposed. The examples show that the method is easy to apply and can achieve acceptable performance.

Journal Article↗
PubMed1997

Evaluation of a pocket-sized turbine spirometer for clinical use with children.

The results of pulmonary function testing with a turbine spirometer (TS) and a bell spirometer (BS) of a randomized group of 275 patients aged 4-18 years were compared. In the TS, an inexpensive device without graphical display was used. The difference BS minus TS (d) for forced expiratory volume in 1 s (FEV1) was calculated. The results indicate that the FEV1 might be overestimated by the TS, and that the difference of the readings of FEV1 between the spirometers increases with airway obstruction. The TS should be used with caution in young patients with asthma.

Adolescent↗
PubMed2005

Discharge of lubricant from air turbine handpieces.

OBJECTIVE: To demonstrate and quantify the discharge of lubricating oil from high-speed air turbine handpieces whilst running. MATERIALS AND METHODS: Dye-marked oil (Kavospray, KaVo) was used to lubricate four handpieces (Quiet-Air, Midwest) and the air discharged from around the lower bearing was directed at the moving chart paper on a recorder whilst running for 40 minutes. Secondly, seven new handpieces (Quiet-Air, 300SE, Midwest; Topair 796, Topair 795, W+H; VIP-Sigma, Pana-air, NSK; Lares, Lares Research) were cleaned, weighed and then lubricated with unmarked oil (Kavospray, KaVo). Oil discharge was determined gravimetrically over runs of 240 minutes. Data were fitted to the logistic dose response function. RESULT: The dye-marked oil tests showed that oil was discharged for at least 40 minutes in the direction of the bur. The gravimetric tests showed that oil continued to be discharged up to at least 240 minutes, and that the usual practice of removing excess lubricant by running for 1-2 minutes was ineffective in preventing cut-surface contamination. SIGNIFICANCE: Bonding procedures in dentistry may be jeopardised by oil contamination from handpiece lubricants. Decontamination with a detergent is suggested as a means of ensuring effective adhesive dentistry.

Air Pollution, Indoor↗
PubMed1998

History of the Kolff Laboratory turbine driven electrohydraulic artificial heart.

The concept of an electrically powered total artificial heart has been pursued by Dr. Kolff and his associates since the 1960s. Since the 1980s these efforts have been concentrated upon the development of the electrohydraulic total artificial heart, a turbine pump powered by a brushless DC motor. Dr. Kolff realized the benefits of pulsatile flow and device response to Starling's Law, and these concepts have formed the basis of subsequent design decisions. Design iterations have both solved existing problems and exposed new challenges. The current device design is greatly improved over early attempts due to the incorporation of technologies that have recently become available as the result of progress in the fields of materials and electronics and due to the lessons learned over many years of research under the guidance of Dr. Kolff. This article describes, from its inception, the last major research project of Dr. Kolff prior to his retirement. The discussion centers around development, problems and their solutions, and the reasoning for given solutions.

Animals↗
PubMedDate not supplied

Fever of undetermined etiology after cleaning of steam turbine condensers.

Two outbreaks of a febrile syndrome marked by chills, headaches, myalgia, nausea, and malaise occurred in workers who had cleaned the steam condensers of electric power turbines. Mean incubation period was 38 hours. Twenty-two of twenty-three exposed men became ill. Clinical and environmental investigation failed to reveal the etiology of the outbreaks. The circumstances and clinical syndrome have points of similarity to fever following inhalation of metal fumes and low-grade, stained cotton dust, and to Pontiac fever.

Adolescent↗