No description available.

Aim: The aim of this research was to measure functional intraoral pressures using a newly developed method; specifically, three areas were examined. Firstly, this new approach to measurement allowed the equilibrium theory of tooth position to be re-addressed. Secondly, it allowed investigation the patterns of pressure change in the palatal midline during water swallowing. Lastly, this approach allowed a preliminary investigation of the affect of the viscosity of the food ingested on the pressures generated in the mouth. Methods: The participants were 6 healthy volunteers (4 males, 2 females) recruited from the post-graduate students at the University of Otago, School of Dentistry. The age range was 25 to 35 years. All had full permanent dentitions, Angle Class I occlusions (normal) with acceptable overbite and overjet relationship, and none of them had a history of previous orthodontic treatment. For each of the subjects a cast chrome-cobalt baseplate was constructed to house 8 miniature strain gauge pressure transducers (Precision Measurement Co. Michigan). The location of the sensors were standardised as follows: Three sensors were paired on the buccal and lingual surfaces of the central, canine and first molar. Two palatal vault sensors were placed in the midline of the palate, one at level of the distal of the first premolar, and the second slightly anterior to the junction of the hard and soft palate. Simultaneous recordings were taken during a set of tasks including water swallows, saliva swallows and food ingestion. Results: The results showed that swallowing was a highly complex wellcoordinated event, and that each individual had their own unique signature pattern of swallowing, characterised by pressure changes of high frequency, in excess of �1000 kPa/s. Conclusions: The analysis of the pressure acting on the teeth showed that although the pattern and magnitude of pressure generated varied among the group, the observation of waveforms would suggest a tendency for no inherent balance between the buccal and the palatal pressures on the teeth during swallowing for any of the individuals tested. This investigation of the pressure in the midline revealed an aspect previously not fully explored; these experiments showed that there were large and persistent negative pressures generated during swallowing, that preceded the positive pressures and which appear important in bolus propulsion The patterns of swallowing and the magnitudes of pressure generated, changed with the different consistency of the various substances ingested. There was a general trend for increased pressures during swallowing of substrates that are more viscous; water showed the lowest pressures, followed by saliva and finally jelly. Keywords: Tongue pressure, Intraoral pressures, Tongue dynamics, Swallowing.

The epithelial sodium channel (ENaC) is the central component of the sodium absorption pathway in epithelia. It is critical for sodium homeostasis and blood pressure control, which is demonstrated by rare genetic disorders such as Liddle�s syndrome and pseudohypoaldosteronism type I, that are associated with hyper- and hypotension, respectively. ENaC is mainly regulated by mechanisms that control the expression of active channels at the cell surface. Ubiquitin ligases of the Nedd4-like family, such as Nedd4 and Nedd4-2 decrease epithelial sodium absorption by binding to and targeting ENaC for endocytosis and degradation. This is most likely achieved by catalyzing the ubiquitination of ENaC. Conversely the serum- and glucocorticoid regulated kinase (SGK) increases ENaC activity. This effect is partly mediated by the interaction of SGK with the ubiquitin ligases Nedd4 and Nedd4-2. SGK is able to bind to both Nedd4 and Nedd4-2, however only Nedd4-2 is phosphorylated by SGK. The phosphorylation of Nedd4-2 inhibits its interaction with ENaC, thus reducing ENaC ubiquitination, thereby increasing surface expression and sodium absorption. Nedd4-like proteins interact with ENaC via their WW-domains. These domains bind PY-motifs (PPXY) present in ENaC subunits. Nedd4 and Nedd4-2 both have four highly similar WW-domains. Previous studies have shown that interaction between Nedd4 and ENaC is mainly mediated by WW-domain 3. SGK also has a PY-motif; therefore it was analyzed whether the WW-domains of Nedd4 and Nedd4-2 mediate binding to SGK. Here, it is shown that single or tandem WW-domains of Nedd4 and Nedd4-2 mediate binding to SGK and that, despite their high similarity, different WW-domains of Nedd4 and Nedd4-2 are involved. These data also suggest that WW-domains 2 and 3 of Nedd4-2 mediate the interaction with SGK in a concerted manner, and that in vitro the phosphorylation of SGK at serine residue 422 increases its affinity for the WW-domains of Nedd4-2. The stimulatory effect of SGK on ENaC activity is partly mediated via Nedd4-2 and will decrease if competition between Nedd4 and Nedd4-2 for binding to SGK occurs. Here it is shown that Nedd4 and Nedd4-2 are located in the same subcellular compartment and that they compete for binding to SGK. Besides its function in the proteasomal degradation pathway ubiquitination is involved in the regulation of membrane protein trafficking, including their endocytosis. ENaC was shown previously to be ubiquitinated. Here, we provide evidence that ENaC can be ubiquitinated differentially depending on its cellular location. Channels residing in the plasma membrane are multiubiquitinated and we suggest that this serves as an internalization signal for ENaC and a control for further trafficking. Cytosolic ENaC is mainly polyubiquitinated, and therefore probably targeted for proteasomal degradation. However, mono- and multiubiquitination of ENaC located within the cytosol is very likely to occur as well. In addition, it is shown that both proteasomal and lysosomal pathways are involved in the regulation of ENaC.

The purpose of this thesis was to investigate the effect of corneal swelling on the accuracy of Goldmann tonometry estimates of intraocular pressure (IOP). In the first experiment, central corneal thickness (CCT, ultrasonic pachymetry), IOP (Goldmann tonometry) and corneal curvature (keratometry) was measured in one eye of 25 subjects every two hours for 24 hours, except for 8 hours overnight (no measurements taken), and for the first two hours after awakening (measurement frequency 20 minutes). CCT (+20.1??10.9 pm) and IOP (+3.1??2.4 mmHg) peaked on eye opening, and then decreased at a similar rate (r=0.967, p<0.001) for the next two hours. Corneal swelling may have influenced the accuracy of Goldmann IOP measurements during this time. In the second and third studies, the CCT, IOP and corneal curvature were measured in both eyes of two groups of 25 subjects before and after the induction of corneal swelling, resulting from two hours of monocular closed eye contact lens wear. The increase in IOP was correlated to the increase in CCT at a rate of 0.33 to 0.48 mmHg per 10 pm, which signified an overestimation error in Goldmann IOP measurement. However, the change in IOP could not be accounted for solely by the change in CCT. In the fourth study, CCT, IOP and corneal curvature were used in conjunction with the Orssengo-Pye algorithm to determine the range of Young's modulus in the normal population, which was 0.29??0.06 MPa. Physiological variations in Young's modulus had a similar effect on Goldmann tonometry to CCT. In the fifth study, the data collected for studies 2 and 3 was used to calculate the Young's modulus changes associated with corneal swelling, again with the assistance of the Orssengo-Pye algorithm. No systematic change in Young's modulus was recorded after contact lens wear, but the model suggested that corneal biomechanical changes were responsible for the remainder of the change in IOP. All experimental results were combined to develop a model to calculate the diurnal variation of Goldmann IOP errors. The likely error in IOP due to overnight corneal swelling was 0.6 to 1.4 mmHg, which may explain as much as 45% (1.4 mmHg) of the 3.1 mmHg diurnal variation of IOP. In summary, small amounts of corneal swelling were shown to have a clinically significant impact on the accuracy of Goldmann tonometry. This may interfere with the measurement of the diurnal variation of IOP, particularly if measurements are taken prior to the resolution of overnight corneal swelling.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 131-142).

Increasing concern over the environmental impact of motor vehicles is driving the need for the development of lighter materials to reduce automobile weight and fuel consumption. Sintered aluminium alloys, with their high strength to weight ratios, have potential applications in the automotive industry, but conventional pressed-and-sintered materials have poor mechanical properties due to the presence of residual porosity in the sintered compact. Residual porosity can be eliminated by Hot Isostatic Pressing (HIPing) or combined sinter-HIPing, but these processes are expensive due to the high gas pressures involved, up to several hundred MPa, and also pose a significant safety hazard. There is a limited amount of evidence in the literature suggesting that applied gas pressures as low as a few MPa may be beneficial to the sintering of aluminium alloys, and it is this idea that the present work explores. Compacts of aluminium alloy 2712 (Al-3.8Cu-1Mg-0.7Si-0.1Sn) were prepared from elemental powders and sintered at 590ºC for up to 60 minutes in a horizontal tube furnace under constant flowing nitrogen or argon at pressures up to 600 kPa. Archimedes’ method was used to measure the density of sintered compacts, and the amount of open and closed porosity. Increasing the nitrogen pressure at the start of the isothermal holding stage to 160 kPa increased the sintering rate compared to standard atmospheric pressure sintering. Increasing the nitrogen pressure further, up to 600 kPa, had no additional benefit. The sintering rate was increased further by applying a 600 kPa nitrogen pressure during both heating and isothermal holding. The elevated nitrogen pressure had a negligible effect on the maximum sintered density achieved, and sintering in argon at elevated pressures had no measurable effect on the sintered density or sintering rate. It was shown that the elevated pressure aids in the closure of pores open to the specimen surface, contrary to HIPing and sinter-HIPing, where the pores must be isolated prior to the application of pressure. It was also shown that at 600 kPa nitrogen pressure, the sintered density was independent of the presence of tin in the alloy. The improvements to sintering seem to be related to the formation of aluminium nitride.

<p>Background and purpose: Volleyball requires a lot of the human body, and</p><p>effective core stability is necessary for the athlete. Our muscles cooperate as a</p><p>chain of motions and core stabilization is the base for the moving muscles.</p><p>The most well-known stabilization muscle is m.transversus abdominis (TrA).</p><p>The purpose of the present study was to evaluate the function of TrA in</p><p>Swedish female elite volleyball players and to observe the influence of eight</p><p>weeks of stabilization exercise on the TrA. Method: 10 female elite</p><p>volleyball players (mean age 24,7 years, range 18-31 years) participated in</p><p>the study. TrA was measured in supine position with a pressure biofeedback</p><p>unit. Subjects were instructed to draw in the abdominal wall without moving</p><p>the pelvis and hold for 10 seconds. After eight weeks of stabilization exercise</p><p>the same test was repeated. Results: 40 % of the subjects had an insufficient</p><p>function of TrA in the initial test. In the second test 78 % had improved their</p><p>results. Conclusion: Stabilization exercise improves the function of TrA and</p><p>should be included in elite practise.</p>

<p>Förekomst av trycksår utgör ett omfattande problem inom hälso- och sjukvården fortfarande trots</p><p>kunskap om förebyggande faktorer som presenteras i litteraturen. Detta medför att det</p><p>förebyggande omvårdnadsarbetet avseende trycksår även i fortsättning kan vara en mycket</p><p>angelägen fråga för sjuksköterskan. Syftet i föreliggande studie är därför att belysa</p><p>omvårdnadsåtgärder som kan utföras i vårdbädden för att förebygga trycksår hos äldre.</p><p>Litteraturstudie valdes som metod. Sökorden; pressure ulcer, prevention, bed and mattresses,</p><p>scoles, skin-care, decubitus ulcer, aged och nursing används. För att elektronisk söka relevanta,</p><p>vetenskapliga artiklar i databaserna CINAHL och MEDLINE. Resultatet bygger på åtta</p><p>vetenskapliga artiklar som kvalitetsgranskades. Vid dataanalysen användes en modifierad form av</p><p>komponenten nr 4 i Viginia Hendersons omvårdnadsteori som teoretisk utgångspunkt. Resultatet</p><p>redovisas utifrån två huvudrubriker med två respektive tre underrubriker. Den första</p><p>huvudrubriken är: Hur kan patienter med risk för utveckling trycksår identifieras? Med</p><p>underrubrikerna: Sjuksköterskans kunskaper och bedömningsinstrument. Resultatet visar att</p><p>sjuksköterskan utför riskbedömningar för att identifiera patienter i riskzon men att dessa inte är</p><p>tillräckligt omfattande och att visa faktorer såsom födo-och vätskeintag saknas i bedömning.</p><p>Studien visar också att det finns många olika riskbedömningsinstrument (skalor) med olika</p><p>variabler för att identifiera patienter som ligger i riskzonen för att utveckla trycksår. Den andra</p><p>huvudrubriken är: Att hjälpa patienten inta lämplig kroppsställning när han / hon ligger samt att</p><p>växla ställning, omfattar underrubrikerna: intervall, position och hjälpmedel. Resultatet visar att</p><p>vändning på en tryckreducerande madrass leder till minskning av trycksår grad II-IV. Litteraturen</p><p>visar även att patientens position i vårdbädden inte bör överstiga 30 grader av huvudändan för att</p><p>undvika för höga tryck mot korsbenet generellt ger lägre tryck på patientens hud. Hjälpmedel som</p><p>rekommenderas för tryckavlastning på häl och korsben är exempelvis gelkuddar.</p>

Improved methods of determining temperature transients in reactor systems are desired because of recent interest in Pressurized Thermal Shock (PTS) issues. The research presented herein was performed in support of the Nuclear Regulatory Commission's effort to re-evaluate its existing PTS rules. These rules are particularly important to the re-licensing of aging nuclear power plants. The much advanced computational power available to industry may offer a tool that allows the accurate calculation of temperatures inside the reactor vessel while not being inaccessibly expensive. It is proposed that an off-the-shelf Computational Fluid Dynamic (CFD) code, STAR-CD, can be a competitive tool in solving the thermal hydraulic domain of a reactor system. A comparison of the methodology and accuracy of the code types that have been previously used in PTS and one that has not been used extensively, CFD, is provided. A review of the literature shows that computer codes have been validated for solving PTS scenarios. The highly specialized program, REMIX, has been utilized extensively from 1986 to 1991 to interpret accident scenarios in reactor systems. Other programs are also available that can calculate downcomer temperatures including system and CFD type codes. Three codes representing the three different types of programs available are described in detail in the literature review section. Data appropriate for assessing a program's ability to calculate the response of a system to a PTS scenario is available from the current matrix of PTS tests being completed at the APEX-CE facility of the Oregon State University Nuclear Engineering department. The facility is a reduced scale integral test facility originally built for modeling the then-proposed AP-600 plant designed by Westinghouse. For the current test series, the facility was modified to model the Palisades nuclear power plant, a Combustion Engineering Pressurized Water Reactor (PWR). Two of the tests were chosen for their PTS typical conditions to compare with calculations of STAR-CD, REMIX, and RELAP. The computer models in each of the programs were either created, modified from a previous version, or the calculations for the comparisons were contributed. The downcomer temperatures at several locations and cold leg temperature gradients, where available, were extracted from the data and calculations and compared. Comparisons are presented in chapter 5 with graphs, along with some interpretation of the comparisons. It was found that STAR-CD agreed best with the data set in the downcomer and is the only program that calculated the temperature gradient in the cold legs. The agreement of STAR-CD with the cold leg data is also very good. REMIX and RELAP calculations agreement with data for downcomer temperatures are found to be good for all comparisons made, qualitatively more than quantitatively when contrasted with the STAR-CD calculations. / Graduation date: 2002

Alicyclobacillus acidoterrestris is a spore-forming food spoilage bacterium. Its spore is problematic to the juice industry because of its ability to grow in low pH environments and survive pasteurization processes. The purpose of this study was to investigate the effect of the non-thermal technology, high pressure homogenization (HPH) and the antimicrobial compound, dimethyl dicarbonate (DMDC), on inactivation of A. acidoterrestris, in a broth system. Vegetative cells and spores of five strains of A. acidoterrestris (N-1100, N-1108, N-1096, SAC and OS-CAJ) were screened for their sensitivity to HPH (0, 100, 200 and 300 MPa) in Bacilllus acidoterrestris thermophilic (BAT) broth. Strain SAC (most resistant) and OS-CAJ (least resistant) were further tested for their sensitivity to 250 ppm DMDC. This was followed by evaluation of combined effects of HPH and DMDC against strain SAC. Effects of HPHand DMDC treatment combinations (no DMDC, 250 ppm DMDC added 12 h before, 2 h before, immediately before, and immediately after 300 MPa HPH treatment) on spores of SAC over a 24-h period were evaluated. After all treatments, samples were serially diluted and surface plated onto BAT agar, and the populations were determined after incubation at 44 &degC for 48 h. All HPH and DMDC treatments significantly (P<0.05) inhibited growth of vegetative cells, spores were less affected by these treatments. HPH caused a 1-to 2-log reduction in vegetative cell populations at 300 MOa for four strains, but only about 0.5-log reduction of SAC strain. Spores of all five strains were not significantly reduced by HPH. DMDC also slowed growth of vegetative cells significantly. For vegetative cells of SAC and OS-CAJ, 250 ppm DMDC reduced the population by about 2 log whereas spore population was reduced by less than 0.5 log. The addition of DMDC together with HPH slightly enhanced the inactivation effect over a 24-h period as compared with treatment with HPH alone. These results demonstrate that HPH and DMDC show promise for aiding in control of growth of vegetative cells of A. acidoterrestris. However, neither treatment alone or in combination, is very effective against spores.