Read by QxMD icon Read

Stress in jet pilots

Kiyong Na, Hyun-Soo Kim
Jet fighter pilots experience high gravitational acceleration forces in the cephalocaudal direction (+Gz), causing severe stress. Stress affects different physiological functions of the gastrointestinal tract. Although the effects of exposure to hypergravity on cardiovascular and cerebral functions have been the subject of numerous studies, crucial information regarding potential pathophysiological alterations following hypergravity exposure in the gastrointestinal tract is lacking. We recently documented a significant decrease in gastric secretory activity in rats after acute exposure to hypergravity...
May 9, 2017: Oncotarget
Jiying Cai, Wenge Hao, Cong Zhang, Jiaqi Yu, Ting Wang
To reveal the formation mechanism of a pulse-jet airflow's cleaning effect in a filter bag, a theoretical model is built by using the theory of the gas jet and unitary adiabatic flow according to given specifications and dimensions of the bags and resistance characteristics of the cloth and dust layer. It is about the relationship between cleaning system structure and operating parameters. The model follows the principle that the flow and kinetic energy of jet flow injected into a filter bag should be consistent with the flow of cleaning airflow in the bag and the pressure drop flowing through the filter cloth and dust layer...
December 2017: Journal of the Air & Waste Management Association
Christian J Roth, Eva Haeussner, Tanja Ruebelmann, Franz V Koch, Christoph Schmitz, Hans-Georg Frank, Wolfgang A Wall
Ischemic placental disease is a concept that links intrauterine growth retardation (IUGR) and preeclampsia (PE) back to insufficient remodeling of uterine spiral arteries. The rheological consequences of insufficient remodeling of uterine spiral arteries were hypothesized to mediate the considerably later manifestation of obstetric disease. However, the micro-rheology in the intervillous space (IVS) cannot be examined clinically and rheological animal models of the human IVS do not exist. Thus, an in silico approach was implemented to provide in vivo inaccessible data...
January 19, 2017: Scientific Reports
Ahmet Akın, Cengiz Ozturk, Mustafa Aparci, Tolga Cakmak, Suleyman Metin, Sevket Balta, Ahmet Sen
BACKGROUND: Pilots are exposed to various physical and hemodynamic stresses during flight. Aortic dilatation may be one of the important consequences of flight-related stress. In this study, we evaluated whether or not variation in aortic diameter was associated with the type of aircraft and the age of pilots. MATERIALS AND METHODS: Medical records of 87 jet aircraft pilots (JP) (mean age = 30.0 ± 7.0 years) and 65 non-jet aircraft pilots (NJP) (mean age = 32.63 ± 5...
December 2015: Military Medicine
Paola Verde, Pierandrea Trivelloni, Gregorio Angelino, Fabio Morgagni, Enrico Tomao
INTRODUCTION: In jet pilots, the neck is stressed by dynamic loading and there is growing concern about possible neck damage in pilots of new agile aircraft. Jet pilots often report neck pain after flight so intense that their operational capability may be affected. However, there is no clear evidence of structural damage related to the operational exposure. METHODS: We compared 35 F-16 pilots with 35 age-matched Eurofighter Typhoon pilots. All subjects completed an anonymous questionnaire on their flight activity and neck pain...
April 2015: Aerospace Medicine and Human Performance
Cengiz Ozturk, Mustafa Aparci, Tolga Cakmak, Suleyman Metin, Sevket Balta, Ahmet Sen
INTRODUCTION: Syncope may be the initial clinical presentation of atrial fibrillation (AF) and has a great potential for incapacitation during flight. Herein is presented the case of a jet pilot who had paroxysmal palpitations accompanied with presyncope which progressed to syncope and was found to be associated with AF. CASE REPORT: A 23-yr-old male jet pilot had a sudden syncope at the fifth minute of his presentation during the daily flight briefing. After he regained consciousness, he was transferred to the intensive care unit of the military hospital...
September 2014: Aviation, Space, and Environmental Medicine
Florian von Knobelsdorff-Brenkenhoff, Ralf F Trauzeddel, Alex J Barker, Henriette Gruettner, Michael Markl, Jeanette Schulz-Menger
BACKGROUND: Aortic remodeling after aortic valve replacement (AVR) might be influenced by the postoperative blood flow pattern in the ascending aorta. This pilot study used flow-sensitive four-dimensional magnetic resonance imaging (4D-flow) to describe ascending aortic flow characteristics after various types of AVR. METHODS: 4D-flow was acquired in 38 AVR patients (n=9 mechanical, n=8 stentless bioprosthesis, n=14 stented bioprosthesis, n=7 autograft) and 9 healthy controls...
January 1, 2014: International Journal of Cardiology
Marco Lucertini, Paola Verde, Pierandrea Trivelloni
BACKGROUND: Airsickness (AS) still represents a major issue in aviation medicine and affects many student pilots and aircrew members. This study aimed at producing an update of the Italian Air Force rehabilitation program for AS, including data on a prolonged follow-up (> 8 yr). METHODS: Data from 20 military pilots with a past history of rehabilitation for incapacitating AS were compared to those of 65 normal controls. All individuals from both samples were categorized as dropouts or successfully employed in fast jets, multiengine air carriers, or helicopters...
November 2013: Aviation, Space, and Environmental Medicine
Michael D Hope, Thomas A Hope, Stephen E S Crook, Karen G Ordovas, Thomas H Urbania, Marc T Alley, Charles B Higgins
Blood flow imaging with 3-dimensional time-resolved, phase-contrast cardiac magnetic resonance (4-dimensional [4D] Flow) is an innovative and visually appealing method for studying cardiovascular disease that allows quantification of important secondary vascular parameters including wall shear stress. The hypothesis of this pilot study is that 4D Flow will become a powerful tool for characterizing the relationship of aortic valve-related flow dynamics, especially with bicuspid aortic valve (BAV), and progression of ascending aortic (AsAo) dilation...
July 2011: JACC. Cardiovascular Imaging
Alvin W Nienow, Mikkel Nordkvist, Christopher A Boulton
Scale-up/scale-down techniques are vital for successful and safe commercial-scale bioprocess design and operation. An example is given in this review of recent studies related to beer production. Work at the bench scale shows that brewing yeast is not compromised by mechanical agitation up to 4.5 W/kg; and that compared with fermentations mixed by CO(2) evolution, agitation ≥ 0.04 W/kg is able to reduce fermentation time by about 20%. Work at the commercial scale in cylindroconical fermenters shows that, without mechanical agitation, most of the yeast sediments into the cone for about 50% of the fermentation time, leading to poor temperature control...
August 2011: Biotechnology Journal
Marco Di Rienzo, Paolo Castiglioni, Paolo Meriggi, Francesco Rizzo, Pierandrea Trivelloni, Salvatore Cacopardo, Anton Giulio Guadagno
The Push-Pull Effect (PPE) is a physiological phenomenon defined as a reduction of +Gz tolerance induced by a previous exposure to a -Gz acceleration, that may lead to loss of consciousness. Aim of this study was to evaluate, for the first time, the cardiac rhythm changes associated with PPE during real flights. Data were collected in 3 pilots during flights on the Aermacchi MB- 339-CD aircraft. In each flight, lasting about 60 minutes, ECG, respiration and 3D accelerations were recorded by a new smart garment (the MagIC System)...
2010: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
David G Newman, Robin Callister
INTRODUCTION: Fighter pilots report G tolerance increases with regular exposure. Our previous work has shown that the cardiovascular system of +Gz-adapted fighter pilots responds differently to orthostatic challenges than that of non-pilots. A +Gz training effect in pilots after repetitive +Gz exposure has also been shown. Individual pilot factors such as flying experience may have a role in +Gz adaptation. In this study, we investigated the relationship between flying hours (a marker of cumulative +Gz exposure) and mean arterial blood pressure (MAP) response to head-up tilt (HUT; a marker of enhanced cardiovascular performance)...
August 2009: Aviation, Space, and Environmental Medicine
Gero Kinzinger, Norbert Gülden, Faruk Yildizhan, Benita Hermanns-Sachweh, Peter Diedrich
AIM: As a clinical pilot study using the skeletonized, periodontally/miniscrew-anchored Distal Jet appliance, this study aimed to verify the positional stability of the palatally-inserted paramedian miniscrews when subjected to loading for several months, hence to assess the efficacy of the supporting anchorage design. MATERIAL AND METHOD: Sixteen miniscrews (8-9 mm in length, 1.6 mm in diameter, polished surface) were inserted in the anterior region of the palate at paramedian locations...
March 2008: Journal of Orofacial Orthopedics, Fortschritte der Kieferorthopädie
Laurence D Fechter, Caroline Gearhart, Sherry Fulton, Jerry Campbell, Jeffrey Fisher, Kwangsam Na, David Cocker, Alisa Nelson-Miller, Patrick Moon, Benoit Pouyatos
Ethylbenzene + toluene are known individually to have ototoxic potential at high exposure levels and with prolonged exposure times generally of 4-16 weeks. Both ethylbenzene + toluene are minor constituents of JP-8 jet fuel; this fuel has recently been determined to promote susceptibility to noise-induced hearing loss. Therefore, the current study evaluates the ototoxic potential of combined exposure to ethylbenzene + toluene exposure in a ratio calculated from the average found in three laboratories. Rats received ethylbenzene + toluene by inhalation and half of them were subjected simultaneously to an octave band of noise (OBN) of 93-95 dB...
August 2007: Toxicological Sciences: An Official Journal of the Society of Toxicology
Orit Lurie, Yehuda Zadik, Shmuel Einy, Ricardo Tarrasch, Gil Raviv, Liav Goldstein
BACKGROUND: Bruxism is the diurnal or nocturnal para-functional habit of clenching or grinding the teeth and affects 5-10% of the general western population. Bruxism can cause pain and irreversible damage to the teeth, periodontium, masticatory muscles, and temporo-mandibular joint. Variables such as general stress, work-related stress, and personality traits have been increasingly considered as initiating, predisposing, and perpetuating factors for bruxism. We sought to evaluate the potential of work-related stress and personality factors to induce bruxism among military pilots and non-pilot officers...
February 2007: Aviation, Space, and Environmental Medicine
Yasutami Otsuka, Akihiko Onozawa, Yoshinori Miyamoto
INTRODUCTION: The levels of urinary noradrenaline (NAd), adrenaline (Ad) and salivary cortisol (Cor) were determined in student and instructor pilots during Phase 1 (training with propeller engine; PH1), and Phase 2 (training with jet engine; PH2) flight training. METHODS: The subjects in PH1 were 30 students and 33 instructors, and in PH2 were 17 students and 15 instructors. Urine and saliva were collected approximately 30 min before and 20 min after the flights...
April 2006: Aviation, Space, and Environmental Medicine
Francesco Tomei, Simone De Sio, Enrico Tomao, Vincenza Anzelmo, Tiziana Paola Baccolo, Manuela Ciarrocca, Emilia Cherubini, Valentina Valentini, Assunta Capozzella, Maria Valeria Rosati
The role of occupational exposure to noise as a hypertension risk factor has not been established sufficiently. The aim of the study is to evaluate whether chronic exposure to different levels of noise in two groups of pilots, operating with two types of aircraft, could be a risk for hypertension, what relevance the parameters (intensity, duration and type) of exposure can have and, lastly, whether there are any links between hearing impairment and hypertension. After excluding pilots with confounding factors, a study was made of 77 male pilots of turboprop planes (group A) and 224 male pilots of jet aircraft (group B), matched by age and working life...
April 2005: International Journal of Environmental Health Research
Katharina Brodka-Pfeiffer, Peter Langguth, Peter Grass, Heribert Häusler
In order to obtain the optimal particle size distribution for pharmaceutical powders in dry powder inhalers the particles have to be micronised. In most cases the process of micronisation is connected with a high input of energy which induces disorder and defects on the surface of the drug particles and as a result changes in the crystallinity. Consequently, changes in the physical stability of the powders may occur. To investigate changes on the physical stability of the powder, different analytical methods are used in the present investigation: laser diffraction, Differential Scanning Calorimetry (DSC), isothermal microcalorimetry and DVS-method...
November 2003: European Journal of Pharmaceutics and Biopharmaceutics
No abstract text is available yet for this article.
1964: Comptes Rendus des Séances de la Société de Biologie et de Ses Filiales
William W Melek, Ziren Lu, Alex Kapps, Bob Cheung
Dynamic and fuzzy models for a typical subject's cardiovascular response to the orthostatic stress have been developed based on experimental data. In our original study (Cheung et al., 1999), arterial blood pressure (BP) time-series data were obtained using a man-rated tilt table that applies gigahertz-acceleration transitions from +0.861 Gz [head-up (HU)] to -0.707 G [head-down (HD)] and back to +0.861 Gz (HU) using either pitch or roll rotations (Cheung et al., 1999). G transitions of different duration and onset rates are common in fighter maneuvers...
December 2002: IEEE Transactions on Bio-medical Engineering
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"