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Sample records for inter-arm pressure difference

  1. Association of Inter-Arm Systolic Blood Pressure Difference with Coronary Atherosclerotic Disease Burden Using Calcium Scoring.

    Science.gov (United States)

    Her, Ae Young; Cho, Kyoung Im; Garg, Scot; Kim, Yong Hoon; Shin, Eun Seok

    2017-09-01

    There are no sufficient data on the correlation between inter-arm blood pressure (BP) difference and coronary atherosclerosis found using coronary artery calcium score (CACS). We aimed to investigate if the increased difference in inter-arm BP is independently associated with severity of CACS. Patients who had ≥3 cardiovascular risk factors or an intermediate Framingham Risk Score (FRS; ≥10) were enrolled. Inter-arm BP difference was defined as the absolute difference in BP in both arms. Quantitative CACS was measured by using coronary computed tomography angiography with the scoring system. A total of 261 patients were included in this study. Age (r=0.256, parm systolic BP (SBP; r=0.172, p=0.005), mean of left arm SBP (r=0.190, p=0.002), inter-arm SBP difference (r=0.152, p=0.014), and the FRS (r=0.278, parm SBP difference (≥6 mm Hg) was significantly associated with CACS ≥300 [odds ratio (OR) 2.17, 95% confidence interval (CI) 1.12-4.22; p=0.022]. In multivariable analysis, the inter-arm SBP difference ≥6 mm Hg was also significantly associated with CACS ≥300 after adjusting for clinical risk factors (OR 2.34, 95 % CI 1.06-5.19; p=0.036). An increased inter-arm SBP difference (≥6 mm Hg) is associated with coronary atherosclerotic disease burden using CACS, and provides additional information for predicting severe coronary calcification, compared to models based on traditional risk factors. © Copyright: Yonsei University College of Medicine 2017

  2. Handedness and gender influence blood pressure in young healthy men and women: A pilot study

    Directory of Open Access Journals (Sweden)

    Rueda I

    2016-01-01

    Full Text Available Objective. The type and level of sex steroids influence blood pressure (BP. It has been suggested that functional brain asymmetries may be influenced by sex hormones. In addition, there are inter-arm differences in BP not yet related with handedness. In this study, we hypothesize a possible association between sex hormones, handedness, and inter-arm differences in blood pressure.

  3. Interarm difference in blood pressure

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels

    2014-01-01

    The present study aimed at examining the interarm difference in blood pressure and its use as an indicator of peripheral arterial disease (PAD). Data were included from consecutive patients referred from their general practitioner to our vascular laboratory for possible PAD aged 50 years or older...... without known cardiac disease, renal disease, or diabetes mellitus. 824 patients (453 women) with mean age of 72 years (range: 50-101) were included. 491 patients had a diagnosis of hypertension and peripheral arterial disease (PAD) was present in 386 patients. Systolic blood pressure was 143 ± 24 mm......Hg and 142 ± 24 mmHg on the right and left arm, respectively (P = 0.015). The interarm difference was greater in patients with hypertension (P = 0.002) and PAD (P blood pressure was reproducible...

  4. Dependency of radon entry on pressure difference

    International Nuclear Information System (INIS)

    Kokotti, H.; Kalliokoski, P.

    1992-01-01

    Radon levels, ventilation rate and pressure differences were monitored continuously in four apartment houses with different ventilation systems. Two of them were ventilated by mechanical exhaust, one by mechanical supply and exhaust, and one by natural ventilation. The two-storey houses were constructed from concrete elements on a slab and located on a gravel esker. It was surprising to find that increasing the ventilation rate increased levels of radon in the apartments. Increased ventilation caused increased outdoor-indoor pressure difference, which in turn increased the entry rate of radon and counteracted the diluting effect of ventilation. The increase was significant when the outdoor-indoor pressure difference exceeded 5 Pa. Especially in the houses with mechanical exhaust ventilation the pressure difference was the most important factor of radon entry rate, and contributed up to several hundred Bq m -3 h -1 . (Author)

  5. Instationary pressure, pressure difference, and temperature curves in a full-pressure containment

    International Nuclear Information System (INIS)

    Mansfeld, G.

    1975-05-01

    The time dependent short-term pressure, temperature and pressure difference-time histories following a loss-of-coolant accident at the primary system in full pressure containments of water cooled nuclear power reactors, which are important for the design of such containments are treated. Therefore pressure, temperature and pressure difference-time histories calculated by the mathematical model and computer code ZOCO VI have been compared with the experiment C1 of the German research program RS 50 'Druckverteilung im Containment'. This comparison showed a partly good agreement between theory and experiemt and gave a first insight into the simulation of the physical phenomena occurring during this short-term behaviour. (orig.) [de

  6. Membrane distillation against a pressure difference

    NARCIS (Netherlands)

    Keulen, L.; Ham, L.V. van der; Kuipers, N.J.M.; Hanemaaijer, J.H.; Vlugt, T.J.H.; Kjelstrup, S.

    2017-01-01

    Membrane distillation is an attractive technology for production of fresh water from seawater. The MemPower® concept, studied in this work, uses available heat (86 °C) to produce pressurized water (2.2 bar and 46 °C) by membrane distillation, which again can be used to power a turbine for

  7. Mean Blood Pressure Difference among Adolescents Based on Dyssomnia Types

    OpenAIRE

    Krisnarta Sembiring; Oke Rina Ramayani; Munar Lubis

    2018-01-01

    BACKGROUND: Dyssomnia is the most frequent sleep disturbance and associated with increased blood pressure. There has been no study determining the difference in mean blood pressure based on dyssomnia types among adolescents. OBJECTIVE: To determine the difference in mean blood pressure among adolescents based on dyssomnia types. METHODS: a Cross-sectional study was conducted in SMP Negeri 1 Muara Batang Gadis in April 2016. Samples were students having sleep disturbance based on Sleep...

  8. Mean Blood Pressure Difference among Adolescents Based on Dyssomnia Types.

    Science.gov (United States)

    Sembiring, Krisnarta; Ramayani, Oke Rina; Lubis, Munar

    2018-02-15

    Dyssomnia is the most frequent sleep disturbance and associated with increased blood pressure. There has been no study determining the difference in mean blood pressure based on dyssomnia types among adolescents. To determine the difference in mean blood pressure among adolescents based on dyssomnia types. Cross-sectional study was conducted in SMP Negeri 1 Muara Batang Gadis in April 2016. Samples were students having sleep disturbance based on Sleep Disturbance Scale for Children (SDSC) questionnaire. Stature and blood pressure data were collected along with demographic data and sleep disorder questionnaire. Analyses were done with Kruskal-Wallis test and logistic regression. P - value blood pressure (DBP) was 111.1 (SD 16.46) mmHg and 70.3 (SD 11.98) mmHg respectively. Mean SDSC score was 49.7 (SD 8.96), and the most frequent dyssomnia type was disorders of initiating and maintaining sleep. Age and sex were not the risk factors of hypertension in dyssomnia. There was a significant difference in mean SBP (P = 0.006) and DBP (P = 0.022) based on dyssomnia types. Combination dyssomnia type had the highest mean blood pressure among dyssomnia types. There is a significant difference in mean blood pressure among adolescents based on dyssomnia types.

  9. Pulse pressure and diabetes treatments: Blood pressure and pulse pressure difference among glucose lowering modality groups in type 2 diabetes.

    Science.gov (United States)

    Alemi, Hamid; Khaloo, Pegah; Mansournia, Mohammad Ali; Rabizadeh, Soghra; Salehi, Salome Sadat; Mirmiranpour, Hossein; Meftah, Neda; Esteghamati, Alireza; Nakhjavani, Manouchehr

    2018-02-01

    Type 2 diabetes is associated with higher pulse pressure. In this study, we assessed and compared effects of classic diabetes treatments on pulse pressure (PP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) in patients with type 2 diabetes.In a retrospective cohort study, 718 non-hypertensive patients with type 2 diabetes were selected and divided into 4 groups including metformin, insulin, glibenclamide+metformin, and metformin+insulin. They were followed for 4 consecutive visits lasting about 45.5 months. Effects of drug regimens on pulse and blood pressure over time were assessed separately and compared in regression models with generalized estimating equation method and were adjusted for age, duration of diabetes, sex, smoking, and body mass index (BMI).Studied groups had no significant change in PP, SBP, and DBP over time. No significant difference in PP and DBP among studied groups was observed (PP:P = 0.090; DBP:P = 0.063). Pairwise comparisons of PP, SBP, and DBP showed no statistically significant contrast between any 2 studied groups. Interactions of time and treatment were not different among groups.Our results demonstrate patients using metformin got higher PP and SBP over time. Averagely, pulse and blood pressure among groups were not different. Trends of variation in pulse and blood pressure were not different among studied diabetes treatments.

  10. Plantar Pressure Variation during Jogging with Different Heel Height

    Directory of Open Access Journals (Sweden)

    Y. D. Gu

    2013-01-01

    Full Text Available This paper presents the key testing and analysis results of an investigation on the effect of heel height on the plantar pressure over different foot areas in jogging. It is important in improving the understanding of jogging with high heels and damage/injury prevention. It can also potentially guide the development of suitable/adaptive exercise schemes in between daily activities with high heels. In this work, plantar pressure data were collected from 10 habituated healthy female subjects (aged 21–25 years at their natural jogging speed with three different conditions: flat heeled shoes (0.8 cm, low heeled shoes (4.0 cm, and high heeled shoes (6.6 cm. Data analysis showed significantly differences in plantar pressure distribution associated with the heel heights with increased pressure in the first metatarsal region and decreased pressure in the lateral metatarsal and midfoot sections. However, there is no significant alteration of plantar pressure in the central area of the forefoot with jogging gait.

  11. A comparison of shoulder pressure among different patient stabilization techniques.

    Science.gov (United States)

    Suozzi, Brent A; Brazell, Hema D; O'Sullivan, David M; Tulikangas, Paul K

    2013-11-01

    The purpose of this study was to evaluate the pressure placed on the shoulders as a function of varying degrees of head-down tilt (the Trendelenburg position) and to compare these pressures among 3 different patient-positioning systems. Participants were placed in the dorsal-lithotomy position with arms tucked and tilted at 5, 10, 15, 20, 25, and 30 degrees of head-down tilt. Using a manometer, we measured the pressure (centimeters of water) on the shoulders at each angle for 3 support devices: the Skytron shoulder support (Skytron, Grand Rapids, MI), the Allen shoulder support (Allen Medical Systems, Acton, MA), and the Allen Hug-u-Vac. Among 23 participants, body mass index (mean ± SD) was 24.5 ± 4.3 kg/m(2). As the tilt angle increased, so did the shoulder pressure for all support systems. At a 30-degree Trendelenburg position, the Allen Hug-u-Vac transmitted less pressure to the shoulders than the Skytron (right and left, P pressure increases as tilt angle increases. Of the 3 support systems that were tested, the Allen Hug-u-Vac transmitted less pressure to the shoulders at a 30-degree Trendelenburg position than the Skytron and the Allen shoulder support systems. Copyright © 2013 Mosby, Inc. All rights reserved.

  12. Radiation pressure induced difference-sideband generation beyond linearized description

    OpenAIRE

    Xiong, Hao; Fan, Y. W.; Yang, X.; Wu, Y.

    2016-01-01

    We investigate radiation-pressure induced generation of the frequency components at the difference-sideband in an optomechanical system, which beyond the conventional linearized description of optomechanical interactions between cavity fields and the mechanical oscillation. We analytically calculate amplitudes of these signals, and identify a simple square-root law for both the upper and lower difference-sideband generation which can describe the dependence of the intensities of these signals...

  13. Differences in evolutionary pressure acting within highly conserved ortholog groups

    Directory of Open Access Journals (Sweden)

    Aravind L

    2008-07-01

    Full Text Available Abstract Background In highly conserved widely distributed ortholog groups, the main evolutionary force is assumed to be purifying selection that enforces sequence conservation, with most divergence occurring by accumulation of neutral substitutions. Using a set of ortholog groups from prokaryotes, with a single representative in each studied organism, we asked the question if this evolutionary pressure is acting similarly on different subgroups of orthologs defined as major lineages (e.g. Proteobacteria or Firmicutes. Results Using correlations in entropy measures as a proxy for evolutionary pressure, we observed two distinct behaviors within our ortholog collection. The first subset of ortholog groups, called here informational, consisted mostly of proteins associated with information processing (i.e. translation, transcription, DNA replication and the second, the non-informational ortholog groups, mostly comprised of proteins involved in metabolic pathways. The evolutionary pressure acting on non-informational proteins is more uniform relative to their informational counterparts. The non-informational proteins show higher level of correlation between entropy profiles and more uniformity across subgroups. Conclusion The low correlation of entropy profiles in the informational ortholog groups suggest that the evolutionary pressure acting on the informational ortholog groups is not uniform across different clades considered this study. This might suggest "fine-tuning" of informational proteins in each lineage leading to lineage-specific differences in selection. This, in turn, could make these proteins less exchangeable between lineages. In contrast, the uniformity of the selective pressure acting on the non-informational groups might allow the exchange of the genetic material via lateral gene transfer.

  14. Automatic algorithm for monitoring systolic pressure variation and difference in pulse pressure.

    Science.gov (United States)

    Pestel, Gunther; Fukui, Kimiko; Hartwich, Volker; Schumacher, Peter M; Vogt, Andreas; Hiltebrand, Luzius B; Kurz, Andrea; Fujita, Yoshihisa; Inderbitzin, Daniel; Leibundgut, Daniel

    2009-06-01

    Difference in pulse pressure (dPP) reliably predicts fluid responsiveness in patients. We have developed a respiratory variation (RV) monitoring device (RV monitor), which continuously records both airway pressure and arterial blood pressure (ABP). We compared the RV monitor measurements with manual dPP measurements. ABP and airway pressure (PAW) from 24 patients were recorded. Data were fed to the RV monitor to calculate dPP and systolic pressure variation in two different ways: (a) considering both ABP and PAW (RV algorithm) and (b) ABP only (RV(slim) algorithm). Additionally, ABP and PAW were recorded intraoperatively in 10-min intervals for later calculation of dPP by manual assessment. Interobserver variability was determined. Manual dPP assessments were used for comparison with automated measurements. To estimate the importance of the PAW signal, RV(slim) measurements were compared with RV measurements. For the 24 patients, 174 measurements (6-10 per patient) were recorded. Six observers assessed dPP manually in the first 8 patients (10-min interval, 53 measurements); no interobserver variability occurred using a computer-assisted method. Bland-Altman analysis showed acceptable bias and limits of agreement of the 2 automated methods compared with the manual method (RV: -0.33% +/- 8.72% and RV(slim): -1.74% +/- 7.97%). The difference between RV measurements and RV(slim) measurements is small (bias -1.05%, limits of agreement 5.67%). Measurements of the automated device are comparable with measurements obtained by human observers, who use a computer-assisted method. The importance of the PAW signal is questionable.

  15. [Is blood pressure control different in women than in men?].

    Science.gov (United States)

    Oliveras, A; Sans-Atxer, L; Vázquez, S

    2015-01-01

    Blood pressure (BP) evolves with age; until the 50's it is higher in men than in women, equaling and even then increasing in women. The prevalence of controlled BP appears to be similar between the sexes, but the prevalence of cardiovascular disease is higher in women than in men. The possibility that BP influences the cardiovascular risk differently according to sex must therefore be considered. While some studies suggest no difference exists, others have shown evidence of an increased risk in women with respect to men despite equal BP. In this way, it seems that the measurement of ambulatory BP, but not office BP, would mark the differences in the association between BP-gender and cardiovascular risk. It should therefore be investigated the possibility of a different BP goal for women and men, especially by evaluating ambulatory BP. Copyright © 2015 SEHLELHA. Published by Elsevier España, S.L.U. All rights reserved.

  16. Investigating Gender Differences under Time Pressure in Financial Risk Taking.

    Science.gov (United States)

    Xie, Zhixin; Page, Lionel; Hardy, Ben

    2017-01-01

    There is a significant gender imbalance on financial trading floors. This motivated us to investigate gender differences in financial risk taking under pressure. We used a well-established approach from behavior economics to analyze a series of risky monetary choices by male and female participants with and without time pressure. We also used second to fourth digit ratio (2D:4D) and face width-to-height ratio (fWHR) as correlates of pre-natal exposure to testosterone. We constructed a structural model and estimated the participants' risk attitudes and probability perceptions via maximum likelihood estimation under both expected utility (EU) and rank-dependent utility (RDU) models. In line with existing research, we found that male participants are less risk averse and that the gender gap in risk attitudes increases under moderate time pressure. We found that female participants with lower 2D:4D ratios and higher fWHR are less risk averse in RDU estimates. Males with lower 2D:4D ratios were less risk averse in EU estimations, but more risk averse using RDU estimates. We also observe that men whose ratios indicate a greater prenatal exposure to testosterone exhibit a greater optimism and overestimation of small probabilities of success.

  17. Investigating Gender Differences under Time Pressure in Financial Risk Taking

    Directory of Open Access Journals (Sweden)

    Zhixin Xie

    2017-12-01

    Full Text Available There is a significant gender imbalance on financial trading floors. This motivated us to investigate gender differences in financial risk taking under pressure. We used a well-established approach from behavior economics to analyze a series of risky monetary choices by male and female participants with and without time pressure. We also used second to fourth digit ratio (2D:4D and face width-to-height ratio (fWHR as correlates of pre-natal exposure to testosterone. We constructed a structural model and estimated the participants' risk attitudes and probability perceptions via maximum likelihood estimation under both expected utility (EU and rank-dependent utility (RDU models. In line with existing research, we found that male participants are less risk averse and that the gender gap in risk attitudes increases under moderate time pressure. We found that female participants with lower 2D:4D ratios and higher fWHR are less risk averse in RDU estimates. Males with lower 2D:4D ratios were less risk averse in EU estimations, but more risk averse using RDU estimates. We also observe that men whose ratios indicate a greater prenatal exposure to testosterone exhibit a greater optimism and overestimation of small probabilities of success.

  18. Gender differences in blood pressure regulation following artificial gravity exposure

    Science.gov (United States)

    Evans, Joyce; Goswami, Nandu; Kostas, Vladimir; Zhang, Qingguang; Ferguson, Connor; Moore, Fritz; Stenger, Michael, , Dr; Serrador, Jorge; W, Siqi

    Introduction. Before countermeasures to space flight cardiovascular deconditioning are established, gender differences in cardiovascular responses to orthostatic stress, in general, and to orthostatic stress following exposure to artificial gravity (AG), in particular, need to be determined. Our recent determination that a short exposure to AG improved the orthostatic tolerance limit (OTL) of cardiovascularly deconditioned subjects drives the current effort to determine mechanisms of that improvement in men and in women. Methods. We determined the OTL of 9 men and 8 women following a 90 min exposure to AG compared to that following 90 min of head down bed rest (HDBR). On both days (21 days apart), subjects were made hypovolemic (low salt diet plus 20 mg intravenous furosemide) and orthostatic tolerance was determined from a combination of head up tilt and increasing lower body negative pressure until presyncope. Mean values and correlations with OTL were determined for heart rate, blood pressure, stroke volume, cardiac output, total peripheral resistance (Finometer), middle cerebral artery flow velocity (DWL), partial pressure of carbon dioxide (Novametrics) and body segmental impedance (UFI THRIM) at supine baseline, during orthostatic stress to presyncope and at supine recovery. Results. Orthostatic tolerance of these hypovolemic subjects was significantly greater following AG than following HDBR. Exposure to AG increased cardiac output in both men and women and increased stroke volume in women. In addition, AG decreased systolic blood pressure in men, but not women, and increased cerebral flow in women, but not men. In both men and women, AG exposure decreased peripheral resistance and decreased cerebrovascular resistance in women. Men’s heart rate rose more at the end of OTL on their AG, compared to their HDBR, day but women’s fell. Presyncopal stroke volume reached the same level on each day of study for both men and women. Conclusions. In the present

  19. Limited predictability of maximal muscular pressure using the difference between peak airway pressure and positive end-expiratory pressure during proportional assist ventilation (PAV)

    OpenAIRE

    Su, Po-Lan; Kao, Pei-Shan; Lin, Wei-Chieh; Su, Pei-Fang; Chen, Chang-Wen

    2016-01-01

    Background If the proportional assist ventilation (PAV) level is known, muscular effort can be estimated from the difference between peak airway pressure and positive end-expiratory pressure (PEEP) (?P) during PAV. We conjectured that deducing muscle pressure from ?P may be an interesting method to set PAV, and tested this hypothesis using the oesophageal pressure time product calculation. Methods Eleven mechanically ventilated patients with oesophageal pressure monitoring under PAV were enro...

  20. Evaluation of the impact of atmospheric pressure in different seasons on blood pressure in patients with arterial hypertension.

    Science.gov (United States)

    Kamiński, Marek; Cieślik-Guerra, Urszula I; Kotas, Rafał; Mazur, Piotr; Marańda, Witold; Piotrowicz, Maciej; Sakowicz, Bartosz; Napieralski, Andrzej; Trzos, Ewa; Uznańska-Loch, Barbara; Rechciński, Tomasz; Kurpesa, Małgorzata

    2016-01-01

    Atmospheric pressure is the most objective weather factor because regardless of if outdoors or indoors it affects all objects in the same way. The majority of previous studies have used the average daily values of atmospheric pressure in a bioclimatic analysis and have found no correlation with blood pressure changes. The main objective of our research was to assess the relationship between atmospheric pressure recorded with a frequency of 1 measurement per minute and the results of 24-h blood pressure monitoring in patients with treated hypertension in different seasons in the moderate climate of the City of Łódź (Poland). The study group consisted of 1662 patients, divided into 2 equal groups (due to a lower and higher average value of atmospheric pressure). Comparisons between blood pressure values in the 2 groups were performed using the Mann-Whitney U test. We observed a significant difference in blood pressure recorded during the lower and higher range of atmospheric pressure: on the days of the spring months systolic (p = 0.043) and diastolic (p = 0.005) blood pressure, and at nights of the winter months systolic blood pressure (p = 0.013). A significant inverse relationship between atmospheric pressure and blood pressure during the spring days and, only for systolic blood pressure, during winter nights was observed. Int J Occup Med Environ Health 2016;29(5):783-792. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  1. Oscillometric blood pressure measurements: differences between measured and calculated mean arterial pressure.

    NARCIS (Netherlands)

    Kiers, H.D.; Hofstra, J.M.; Wetzels, J.F.M.

    2008-01-01

    Mean arterial pressure (MAP) is often used as an index of overall blood pressure. In recent years, the use of automated oscillometric blood pressure measurement devices is increasing. These devices directly measure and display MAP; however, MAP is often calculated from systolic blood pressure (SBP)

  2. Hydraulic High Pressure Valve Controller Using the In-Situ Pressure Difference

    Science.gov (United States)

    Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor); Hall, Jeffery L. (Inventor)

    2016-01-01

    A hydraulic valve controller that uses an existing pressure differential as some or all of the power source for valve operation. In a high pressure environment, such as downhole in an oil or gas well, the pressure differential between the inside of a pipe and the outside of the pipe may be adequately large to drive a linear slide valve. The valve is operated hydraulically by a piston in a bore. When a higher pressure is applied to one end of the bore and a lower pressure to the other end, the piston moves in response to the pressure differential and drives a valve attached to it. If the pressure differential is too small to drive the piston at a sufficiently high speed, a pump is provided to generate a larger pressure differential to be applied. The apparatus is conveniently constructed using multiport valves, which can be rotary valves.

  3. Blood pressure variations in Subjects with different Haemoglobin ...

    African Journals Online (AJOL)

    Dr Olaleye Samuel

    Blood pressures in 20 steady and crisis states SCD patients ... (p<0.05) lower blood pressure (systolic and diastolic) in SCD in stable (but not in crisis) state .... 2008).The mean values were calculated from a total of three readings in each case. Statistical Analysis. Data were analysed with Microcal origin 5.0 statistical.

  4. Maximum static inspiratory and expiratory pressures with different lung volumes

    Directory of Open Access Journals (Sweden)

    Johnson Monique M

    2006-05-01

    Full Text Available Abstract Background Maximum pressures developed by the respiratory muscles can indicate the health of the respiratory system, help to determine maximum respiratory flow rates, and contribute to respiratory power development. Past measurements of maximum pressures have been found to be inadequate for inclusion in some exercise models involving respiration. Methods Maximum inspiratory and expiratory airway pressures were measured over a range of lung volumes in 29 female and 19 male adults. A commercial bell spirometry system was programmed to occlude airflow at nine target lung volumes ranging from 10% to 90% of vital capacity. Results In women, maximum expiratory pressure increased with volume from 39 to 61 cmH2O and maximum inspiratory pressure decreased with volume from 66 to 28 cmH2O. In men, maximum expiratory pressure increased with volume from 63 to 97 cmH2O and maximum inspiratory pressure decreased with volume from 97 to 39 cmH2O. Equations describing pressures for both sexes are: Pe/Pmax = 0.1426 Ln( %VC + 0.3402 R2 = 0.95 Pi/Pmax = 0.234 Ln(100 - %VC - 0.0828 R2 = 0.96 Conclusion These results were found to be consistent with values and trends obtained by other authors. Regression equations may be suitable for respiratory mechanics models.

  5. Ankle-brachial blood pressure differences in the beach-chair position of the shoulder surgery.

    Science.gov (United States)

    Choi, Jae Chan; Lee, Jong-Hyuk; Lee, Young-Don; Kim, Soon Yul; Chang, Sei-Jin

    2012-12-01

    During shoulder surgery, blood pressure is frequently measured at the ankle. Anesthetic complications may result when ankle blood pressure is higher than brachial blood pressure and anesthesiologists misinterpret ankle blood pressure as brachial blood pressure. Therefore, we investigated whether ankle blood pressure is significantly higher than brachial blood pressure before anesthesia induction, during induction, after tracheal intubation, before beach chair position, and in the beach chair position. Thirty patients requiring general anesthesia for shoulder surgery were included in this study. Ankle and brachial blood pressure were simultaneously measured before induction, during induction, after intubation, before beach chair position, and in the beach chair position. Ankle blood pressure was higher than brachial blood pressure before induction, during induction, after intubation, before beach chair position, and in the beach chair position. Ankle-brachial blood pressure differences in the beach chair condition were much higher than in four other conditions. The correlation coefficient between mean ankle-brachial blood pressure differences before the beach chair position and mean ankle-brachial blood pressure differences in the beach chair position was 0.616. Brachial systolic blood pressure could be predicted by regression equations (R(2) = 0.306-0.771). These results suggest that anesthesiologists should consider these ankle-brachial blood pressure differences when monitoring anesthesia in the beach chair position.

  6. Simultaneously Measured Interarm Blood Pressure Difference and Stroke: An Individual Participants Data Meta-Analysis.

    Science.gov (United States)

    Tomiyama, Hirofumi; Ohkuma, Toshiaki; Ninomiya, Toshiharu; Mastumoto, Chisa; Kario, Kazuomi; Hoshide, Satoshi; Kita, Yoshikuni; Inoguchi, Toyoshi; Maeda, Yasutaka; Kohara, Katsuhiko; Tabara, Yasuharu; Nakamura, Motoyuki; Ohkubo, Takayoshi; Watada, Hirotaka; Munakata, Masanori; Ohishi, Mitsuru; Ito, Norihisa; Nakamura, Michinari; Shoji, Tetsuo; Vlachopoulos, Charalambos; Yamashina, Akira

    2018-04-09

    We conducted individual participant data meta-analysis to examine the validity of interarm blood pressure difference in simultaneous measurement as a marker to identify subjects with ankle-brachial pressure index blood pressure difference >5 mm Hg as being associated with a significant odds ratio for the presence of ankle-brachial pressure index blood pressure difference >15 mm Hg was associated with a significant Cox stratified adjusted hazard ratio for subsequent stroke (hazard ratio, 2.42; 95% confidence interval, 1.27-4.60; P blood pressure differences, measured simultaneously in both arms, may be associated with vascular damage in the systemic arterial tree. These differences may be useful for identifying subjects with an ankle-brachial pressure index of blood pressure in both arms at the first visit. © 2018 American Heart Association, Inc.

  7. Pressure transmission area and maximum pressure transmission of different thermoplastic resin denture base materials under impact load.

    Science.gov (United States)

    Nasution, Hubban; Kamonkhantikul, Krid; Arksornnukit, Mansuang; Takahashi, Hidekazu

    2018-01-01

    The purposes of the present study were to examine the pressure transmission area and maximum pressure transmission of thermoplastic resin denture base materials under an impact load, and to evaluate the modulus of elasticity and nanohardness of thermoplastic resin denture base. Three injection-molded thermoplastic resin denture base materials [polycarbonate (Basis PC), ethylene propylene (Duraflex), and polyamide (Valplast)] and one conventional heat-polymerized acrylic resin (PMMA, SR Triplex Hot) denture base, all with a mandibular first molar acrylic resin denture tooth set in were evaluated (n=6). Pressure transmission area and maximum pressure transmission of the specimens under an impact load were observed by using pressure-sensitive sheets. The modulus of elasticity and nanohardness of each denture base (n=10) were measured on 15×15×15×3mm 3 specimen by using an ultramicroindentation system. The pressure transmission area, modulus of elasticity, and nanohardness data were statistically analyzed with 1-way ANOVA, followed by Tamhane or Tukey HSD post hoc test (α=.05). The maximum pressure transmission data were statistically analyzed with Kruskal-Wallis H test, followed by Mann-Whitney U test (α=.05). Polymethyl methacrylate showed significantly larger pressure transmission area and higher maximum pressure transmission than the other groups (Pdenture bases (Pthermoplastic resin denture base materials. Differences in the modulus of elasticity and nanohardness of each type of denture base were demonstrated. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  8. Prospective Comparative Analysis of 4 Different Intraocular Pressure Measurement Techniques and Their Effects on Pressure Readings.

    Science.gov (United States)

    Berk, Thomas A; Yang, Patrick T; Chan, Clara C

    2016-10-01

    To compare intraocular pressure (IOP) measurement using the Goldmann applanation tonometry (GAT) without fluorescein, with fluorescein strips, with fluorescein droplets, and IOP measurement with Tono-Pen Avia (TPA). This was a prospective comparative clinical analysis. It was performed in clinical practice. The study population consisted of 40 volunteer patients, 1 eye per patient. All patients who were 18 years and older having routine ophthalmological examination were eligible to participate. Active corneal abrasions and/or ulcers, previous glaucoma surgery, or prostheses interfering with GAT measurement were excluded. GAT IOP was measured first without fluorescein, then with fluorescein strip, then with fluorescein droplet, and finally with the TPA device. The main outcome measure was central corneal IOP. Mean±SD IOP measurements for GAT without fluorescein, with fluorescein strip, with fluorescein droplet, and for TPA groups were 12.65±3.01, 14.70±2.82, 15.78±2.64, and 16.33±3.08 mm Hg, respectively. Repeated-measures analysis of variance corrected with the Greenhouse-Geisser estimate ([Latin Small Letter Open E]=0.732) showed that measuring technique had a significant effect on IOP measurements (F2.20,85.59=34.66, P<0.001). The pairwise post hoc testing showed statistically significant mean differences (P≤0.001) between all techniques except when GAT with fluorescein droplet was compared with TPA (P=0.222). The Bland-Altman analyses showed 95% limits of agreement maximum potential discrepancies in measurement ranging from 5.89 mm Hg in the GAT with fluorescein strip versus droplet compared with 11.83 mm Hg in the GAT with fluorescein strip versus TPA comparison. IOP measurement technique significantly impacted the values obtained. The ophthalmologist should ensure consistent measurement technique to minimize variability when following patients.

  9. Does the position or contact pressure of the stethoscope make any difference to clinical blood pressure measurements: an observational study.

    Science.gov (United States)

    Pan, Fan; Zheng, Dingchang; He, Peiyu; Murray, Alan

    2014-12-01

    This study aimed to investigate the effect of stethoscope position and contact pressure on auscultatory blood pressure (BP) measurement. Thirty healthy subjects were studied. Two identical stethoscopes (one under the cuff, the other outside the cuff) were used to simultaneously and digitally record 2 channels of Korotkoff sounds during linear cuff pressure deflation. For each subject, 3 measurements with different contact pressures (0, 50, and 100 mm Hg) on the stethoscope outside the cuff were each recorded at 3 repeat sessions. The Korotkoff sounds were replayed twice on separate days to each of 2 experienced listeners to determine systolic and diastolic BPs (SBP and DBP). Variance analysis was performed to study the measurement repeatability and the effect of stethoscope position and contact pressure on BPs. There was no significant BP difference between the 3 repeat sessions, between the 2 determinations from each listener, between the 2 listeners and between the 3 stethoscope contact pressures (all P > 0.06). There was no significant SBP difference between the 2 stethoscope positions at the 2 lower stethoscope pressures (P = 0.23 and 0.45), but there was a small (0.4 mm Hg, clinically unimportant) significant difference (P = 0.005) at the highest stethoscope pressure. The key result was that, DBP from the stethoscope under the cuff was significantly lower than that from outside the cuff by 2.8 mm Hg (P pressure, this study could suggest that the stethoscope position under the cuff, and closer to the arterial occlusion, might yield measurements closer to the actual invasive DBP.

  10. Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures

    Science.gov (United States)

    2014-11-01

    Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures Allan Fong, MS1,3, Ranjeev...the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the...type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure waveforms. Several network

  11. Generational Differences in Resistance to Peer Pressure among Mexican-Origin Adolescents.

    Science.gov (United States)

    Umana-Taylor, Adriana J.; Bamaca-Gomez, Mayra Y.

    2003-01-01

    Examined whether Mexican origin adolescents who varied by generational status would differ in their resistance to peer pressure. After controlling for gender, resistance to peer pressure varied significantly by generational status. Adolescents with no familial births in the United States were significantly more resistant to peer pressure than…

  12. Pressure ulcer prevention: making a difference across a health authority?

    Science.gov (United States)

    Guy, Heidi; Downie, Fiona; McIntyre, Lyn; Peters, Jeremy

    Pressure ulcers (PUs), their cause and prevention have been discussed in the literature for many decades. Their prevention and management has been the core of a tissue viability nurse's daily clinical and strategic workload. The important point to acknowledge is that not all PUs can be prevented but it is believed most of them can and all preventative measures must be implemented and evaluated. Initial efforts focused on establishing a baseline of incidence and prevalence. More recently, the Department of Health has proposed that PUs could be eliminated in 95% of all NHS patients and incentivised the measurement of PUs and other harms by use of the NHS Safety Thermometer through the introduction of a new initiative. A research company was commissioned to explore which communications interventions would be effective in helping health professionals to prevent and treat PUs. A campaign was subsequently set in motion to educate and inform clinical staff on the cause and prevention of PUs.

  13. Studies on silicon quantum dots prepared at different working pressure

    Directory of Open Access Journals (Sweden)

    Faisal A. Al-Agel

    Full Text Available This research work describes the synthesis and characterization of Si quantum dots of thickness 20 nm prepared on glass/quartz substrate by Physical Vapour Condensation Technique at the working pressure of 5 and 10 Torr with fixed substrate temperature 77 K using liquid nitrogen. The synthesized quantum dots were studied by FESEM, HRTEM, X-ray diffraction, UV–visible spectroscopy, photoluminescence and FTIR spectroscopy. The X-ray diffraction pattern of synthesized quantum dots shows the amorphous nature. FESEM images of synthesized quantum dots suggest that the size of quantum dots varies from 4–6 nm which is further confirmed by HRTEM. On the basis of optical absorbance by UV–visible spectroscopy, a direct band gap has been detected. FTIR spectra suggest that the as-grown Si quantum dots are partially oxidized which is due exposure of samples to air after taking out the samples from the chamber. PL spectra show a broad peak at 444 nm, which may be attributed to the configuration of amorphous Si quantum dots. A slight shift in the peak position has been observed with increase in working pressure from 5 Torr to 10 Torr. The dc conductivity with temperature of Si quantum dots has also been studied from 303 to 454 K. It is evident that the dc conductivity (σdc enhances linearly with temperature, showing that conduction in Si quantum dots is due to an activated action which further verify the semiconductor deportment of these quantum dots. Keywords: Si quantum dots, Thin films, XRD, Optical properties, Electrical properties

  14. Analytical calculations of the rotational transform angles in the torsatron systems with different plasma pressure profiles

    International Nuclear Information System (INIS)

    Kuznetsov, Yu.K.; Pinos, I.B.; Tyupa, V.I.

    1999-01-01

    With formulas for averaging over magnetic surfaces general analytical expressions are here deduced to determine the rotational transform angles in stellarator systems having different plasma pressure profiles

  15. Limited predictability of maximal muscular pressure using the difference between peak airway pressure and positive end-expiratory pressure during proportional assist ventilation (PAV).

    Science.gov (United States)

    Su, Po-Lan; Kao, Pei-Shan; Lin, Wei-Chieh; Su, Pei-Fang; Chen, Chang-Wen

    2016-11-27

    If the proportional assist ventilation (PAV) level is known, muscular effort can be estimated from the difference between peak airway pressure and positive end-expiratory pressure (PEEP) (ΔP) during PAV. We conjectured that deducing muscle pressure from ΔP may be an interesting method to set PAV, and tested this hypothesis using the oesophageal pressure time product calculation. Eleven mechanically ventilated patients with oesophageal pressure monitoring under PAV were enrolled. Patients were randomly assigned to seven assist levels (20-80%, PAV20 means 20% PAV gain) for 15 min. Maximal muscular pressure calculated from oesophageal pressure (P mus, oes ) and from ΔP (P mus, aw ) and inspiratory pressure time product derived from oesophageal pressure (PTP oes ) and from ΔP (PTP aw ) were determined from the last minute of each level. P mus, oes and PTP oes with consideration of PEEPi were expressed as P mus, oes, PEEPi and PTP oes, PEEPi , respectively. Pressure time product was expressed as per minute (PTP oes , PTP oes, PEEPi , PTP aw ) and per breath (PTP oes, br , PTP oes, PEEPi, br , PTP aw, br ). PAV significantly reduced the breathing effort of patients with increasing PAV gain (PTP oes 214.3 ± 80.0 at PAV20 vs. 83.7 ± 49.3 cmH 2 O•s/min at PAV80, PTP oes, PEEPi 277.3 ± 96.4 at PAV20 vs. 121.4 ± 71.6 cmH 2 O•s/min at PAV80, p PAV and underestimates P mus, oes for moderate-gain to high-gain PAV. An optimal P mus, aw could be achieved in 91% of cases with PAV60. When the PAV gain was adjusted to P mus, aw of 5-10 cmH 2 O, there was a 93% probability of PTP oes PAV has limited accuracy. The extrapolated pressure time product from ΔP is usually less than the pressure time product calculated from oesophageal pressure tracing. However, when the PAV gain was adjusted to P mus, aw of 5-10 cmH 2 O, there was a 90% probability of PTP oes and PTP oes, PEEPi within acceptable ranges. This information should be considered when applying

  16. High pressure inactivation of relevant target microorganisms in poultry meat products and the evaluation of pressure-induced protein denaturation of marinated poultry under different high pressure treatments

    Science.gov (United States)

    Schmidgall, Johanna; Hertel, Christian; Bindrich, Ute; Heinz, Volker; Toepfl, Stefan

    2011-03-01

    In this study, the possibility of extending shelf life of marinated poultry meat products by high pressure processing was evaluated. Relevant spoilage and pathogenic strains were selected and used as target microorganisms (MOs) for challenge experiments. Meat and brine were inoculated with MOs and treated at 450 MPa, 4 °C for 3 min. The results of inactivation show a decreasing pressure tolerance in the series Lactobacillus > Arcobacter > Carnobacterium > Bacillus cereus > Brochothrix thermosphacta > Listeria monocytogenes. Leuconostoc gelidum exhibited the highest pressure tolerance in meat. A protective effect of poultry meat was found for L. sakei and L. gelidum. In parallel, the influence of different marinade formulations (pH, carbonates, citrates) on protein structure changes during a pressure treatment was investigated. Addition of sodium carbonate shows a protection against denaturation of myofibrillar proteins and provides a maximum water-holding capacity. Caustic marinades allowed a higher retention of product characteristics than low-pH marinades.

  17. The Phase Envelope of Multicomponent Mixtures in the Presence of a Capillary Pressure Difference

    DEFF Research Database (Denmark)

    Sandoval Lemus, Diego Rolando; Yan, Wei; Michelsen, Michael Locht

    2016-01-01

    Confined fluids such as oil and gas mixtures inside tight reservoirs are systems that can experience high capillary pressure difference between the liquid and gas phases. This capillary pressure difference has an effect on the phase equilibrium and in some cases is considerably high. We presented...

  18. Assessment of plantar pressure in hindfoot relief shoes of different designs.

    Science.gov (United States)

    Hahn, Thomas; Carl, Hans-Dieter; Jendrissek, Andreas; Brem, Matthias; Swoboda, Bernd; Rummel, Philipp; Pauser, Johannes

    2014-01-01

    Although there are several different concepts of hindfoot relief footwear, there are no studies on the extent of pressure reduction to be achieved by this footwear. Therefore, we sought to evaluate the reduction in plantar pressure to be achieved with two different hindfoot relief shoes. Ten healthy volunteers performed three trials at a self-selected speed. Peak pressure values in mass-produced shoes (normal gait) were considered as 100% and were compared with measurements in two differently designed hindfoot relief shoes. Foot portions were defined as heel (0%-15% of total insole length), hindfoot (16%-30%), midfoot (31%-60%), and forefoot (61%-100%). Heel and hindfoot peak pressures were significantly reduced in both shoes compared with normal gait (P shoes. Midfoot peak pressure was not significantly reduced in tested shoes compared with baseline (P > .05) but differed significantly between the two shoes. Forefoot peak pressure was significantly reduced with one of the tested shoes (to a median 73% baseline; P = .004) but not with the other (median, 88% baseline). Hindfoot relief shoes leave a considerable amount of peak pressure, predominantly under the hindfoot. The extent of peak pressure reduction for the heel and the hindfoot varies between different hindfoot relief shoes. Depending on the affected foot area, the kind of hindfoot relief shoe should be carefully chosen.

  19. Comparison of plantar pressure between flat and normal feet when crossing an obstacle at different heights.

    Science.gov (United States)

    Han, Jin-Tae; Lee, Jung-Hoon; Lee, Eun-Ju; Lim, Chang-Hun; Kim, Won-Bok

    2015-01-01

    The purpose of this study is to compare the plantar foot pressure and the center of pressure (COP) pathway of normal and flat feet while crossing an obstacle at different heights. Nineteen subjects (10 normal feet, 9 flat feet) participated in this study. The plantar foot surface was divided into the following seven regions for pressure measurement: two toe regions, three forefoot regions, one midfoot region, and one heel region. A one-way ANOVA with repeated measurements was used to compare the plantar foot pressure of normal and flat feet according to the obstacle height. The trend analysis showed a quadratic trend during level walking for the normal foot group, but a linear trend appeared as the obstacle height increased. In the flat foot group, the trend analysis showed a linear trend regardless of the obstacle height. In the 2nd-3rd metatarsal head region, the plantar pressure of the flat foot group increased more than the normal foot group as the obstacle height increased; however, in the 4th-5th metatarsal head region, the plantar pressure in flat feet was lower than in normal feet. In the heel region, the plantar pressure in both groups generally increased as the obstacle height increased, but the plantar pressure in the flat foot group was lower than in the normal foot group. We believe that, due to a loss of longitudinal arch, the COP path and plantar pressure of flat feet may be different from normal feet when crossing obstacles of different heights.

  20. Differences in foot sensitivity and plantar pressure between young adults and elderly

    NARCIS (Netherlands)

    Machado, A.S.; Bombach, G.D.; Duysens, J.; Carpes, F.P.

    2016-01-01

    OBJECTIVE: The understanding of foot sensitivity and plantar pressure contributes to the design of insoles, shoes, as well as to guide therapeutic interventions. Here we investigate differences in plantar pressure and foot sensitivity between young adults and community-dwelling elderly. METHODS:

  1. Ethnic differences in the association of birth weight and blood pressure

    NARCIS (Netherlands)

    Oberg, Sara; Ge, Dongliang; Cnattingius, Sven; Svensson, Anna; Treiber, Frank A.; Snieder, Harold; Iliadou, Anastasia

    2007-01-01

    Background: African Americans (AAs) not only have higher blood-pressure levels, but also an increased risk of low weight at birth, compared with European Americans (EAs). In light of fetal programming theories, it has been suggested that ethnic differences in blood pressure originate in utero.

  2. Gender Differences in Behavioral and Neural Responses to Unfairness Under Social Pressure.

    Science.gov (United States)

    Zheng, Li; Ning, Reipeng; Li, Lin; Wei, Chunli; Cheng, Xuemei; Zhou, Chu; Guo, Xiuyan

    2017-10-18

    Numerous studies have revealed the key role of social pressure on individuals' decision-making processes. However, the impact of social pressure on unfairness-related decision-making processes remains unclear. In the present study, we investigated how social pressure modulated men's and women's responses in an ultimatum game. Twenty women and eighteen men played the ultimatum game as responders in the scanner, where fair and unfair offers were tendered by proposers acting alone (low pressure) or by proposers endorsed by three supporters (high pressure). Results showed that men rejected more, whereas women accepted more unfair offers in the high versus low pressure context. Neurally, pregenual anterior cingulate cortex activation in women positively predicted their acceptance rate difference between contexts. In men, stronger right anterior insula activation and increased connectivity between right anterior insula and dorsal anterior cingulate cortex were observed when they receiving unfair offers in the high than low pressure context. Furthermore, more bilateral anterior insula and left dorsolateral prefrontal cortex activations were found when men rejected (relative to accepted) unfair offers in the high than low pressure context. These findings highlighted gender differences in the modulation of behavioral and neural responses to unfairness by social pressure.

  3. COMPARISON OF PLANTAR PRESSURE DISTRIBUTION BETWEEN DIFFERENT SPEED AND INCLINE DURING TREADMILL JOGGING

    Directory of Open Access Journals (Sweden)

    I-Ju Ho

    2010-03-01

    Full Text Available The aim of this study was to examine the effect of changes in speed and incline slope on plantar pressure distribution of the foot during treadmill jogging. Plantar pressure parameters were measured with the Pedar-X system in twenty healthy girls (mean age of 20.7 years, mean height of 1.60m, and a mean weight of 53.35kg. Because variations in walking speed or slope can significantly change the magnitude of plantar pressure, comparisons of plantar pressure distribution between the two independent protocols during treadmill jogging were considered in this study. First, the subjects ran at the same speed of 2 m·s-1 with different incline slopes of 0%, 5%, 10%, and 15%. Second, they ran on the same slope of 0% with different speeds of 1.5 m·s-1, 2.0 m·s-1, and 2.5 m·s-1. The peak pressure of the eight plantar surface areas, apart from the medial forefoot and the hallux, significantly increased (p < 0.05 with an increase of 33% of peak pressure from 1.5 m·s-1 to 2.5 m·s-1 (speed at heel region. In contrast, the peak pressures at the heel, medial fore-foot, toe and hallux decreased significantly (p < 0. 05 with increasing incline slope. At the heel, peak pressure reduced by 27% from 0% to 15% incline, however, pressure at the lateral midfoot region increased as following. Different speeds and incline slopes during jogging were associated with changes in plantar pressures. By systematic investigation of foot kinematics and plantar pressure during jogging with varying incline slope and speed, the results of this study provided further insight into foot biomechanics during jogging

  4. The influence of different auto-ignition modes on the behavior of pressure waves

    International Nuclear Information System (INIS)

    Xu, Han; Yao, Anren; Yao, Chunde

    2015-01-01

    Highlights: • Modes of pressure oscillations in knocking, HCCI and super knock are recognized. • Three representative auto-ignition modes in engines are proposed. • A new method of “Energy Injected” is brought into understanding pressure wave. • Simulation results revealed the decisive factors for these three auto-ignition modes. • Different modes lead to different pressure wave behaviors damaging engines. - Abstract: For internal combustion engines, the knock of Homogeneous Charge Compression Ignition engines, the conventional knock of gasoline engines and the super knock are all caused by the auto-ignition of unburned mixture which leads to the oscillation burning, but their Maximal Pressure Oscillation Amplitude (MPOA) and Maximum Pressure Rising Rate (MPRR) are totally different. In order to explore the reason, we propose three typical auto-ignition modes and then bring up the method of “Energy Injected” (EI) which is based on the experiment measured heat release rate. Through changing the heat source term in the energy equation for different auto-ignition modes, we conducted a series of numerical simulations for these three modes. After that, the following pressure oscillations can be compared and analyzed. The numerical simulation results show that different combustion pressure waves with different oscillation characteristics come from different auto-ignition modes, thus the macroscopic MPRR and MPOA are totally different. Furthermore, the method of “EI” based on the experiment measured heat release rate can accurately and rapidly help to research the formation and propagation of pressure waves in the engine combustion chamber.

  5. Oxygen consumption in EPDM irradiated under different oxygen pressures and at different LET

    International Nuclear Information System (INIS)

    Dely, N.; Ngono-Ravache, Y.; Ramillon, J.-M.; Balanzat, E.

    2005-01-01

    We conceived a novel set-up for measuring the radiochemical yields of oxygen consumption in polymers. The measurement is based on a sampling of the gas mixture with a mass spectrometer, before and after irradiation. We irradiated an ethylene, propylene and 1,4-hexadiene terpolymer (EPDM) with 1 MeV electron and 10.75 MeV/A carbon beams. Samples were irradiated under oxygen within a wide range of pressure (5-200 mbar). The yields under C irradiation are four times smaller than the yields under electron irradiation. This shows that radiooxidation is very sensitive to the linear energy transfer of the projectiles and hence to the heterogeneity of the energy deposition. The oxygen consumption yields do not vary significantly in the range of pressure investigated; even at 5 mbar, the kinetics is still governed by the bimolecular recombination of peroxy radicals

  6. Differences in lumbar and pelvic angles and gluteal pressure in different sitting postures

    OpenAIRE

    Yu, Ji-Su; An, Duk-Hyun

    2015-01-01

    [Purpose] To investigate the effects of erect sitting, slouched posture with cross-legged sitting, and erect posture with cross-legged sitting on the lumbar and pelvic angles, and gluteal pressure. [Subjects] For the experiments, 17 healthy women were recruited. [Methods] All subjects were asked to perform three sitting postures: erect sitting, slouched posture with cross-legged sitting, and erect posture with cross-legged sitting. Lumbar and pelvic angles were measured using a three-dimensio...

  7. Comparison of Plantar Pressure Distribution between Different Speed and Incline During Treadmill Jogging.

    Science.gov (United States)

    Ho, I-Ju; Hou, Yi-You; Yang, Chich-Haung; Wu, Wen-Lan; Chen, Sheng-Kai; Guo, Lan-Yuen

    2010-01-01

    The aim of this study was to examine the effect of changes in speed and incline slope on plantar pressure distribution of the foot during treadmill jogging. Plantar pressure parameters were measured with the Pedar-X system in twenty healthy girls (mean age of 20.7 years, mean height of 1.60m, and a mean weight of 53.35kg). Because variations in walking speed or slope can significantly change the magnitude of plantar pressure, comparisons of plantar pressure distribution between the two independent protocols during treadmill jogging were considered in this study. First, the subjects ran at the same speed of 2 m·s(-1) with different incline slopes of 0%, 5%, 10%, and 15%. Second, they ran on the same slope of 0% with different speeds of 1.5 m·s(-1), 2.0 m·s(-1), and 2.5 m·s(-1). The peak pressure of the eight plantar surface areas, apart from the medial forefoot and the hallux, significantly increased (p jogging were associated with changes in plantar pressures. By systematic investigation of foot kinematics and plantar pressure during jogging with varying incline slope and speed, the results of this study provided further insight into foot biomechanics during jogging. Key pointsThe study aimed to compare the plantar pressure distribution of the foot between different incline and speed during treadmill jogging by using plantar insole measurement system.With the increase of speed, apart from the hallux and medical forefoot, the peak pressure of all regions was raised significantly.As the slope increased, there was reduced peak pressure of the heel, medial forefoot, and hallux and toes.

  8. Differences in center of pressure trajectory between normal and steppage gait

    Science.gov (United States)

    Jamshidi, Nima; Rostami, Mostafa; Najarian, Siamak; Menhaj, Mohammad Bagher; Saadatnia, Mohammad; Salami, Firooz

    2010-01-01

    BACKGROUND: This pilot study aimed to assess the differences in center of pressure trajectory in neuropathic patients with steppage gait. Steppage gait has previously been evaluated by several biomechanical methods, but plantar pressure distribution has been much less studied. The purpose of this study was to analyze the changes in center of pressure trajectory using a force plate. METHODS: The steppage gait group was selected from the patients using drop foot brace (25 male) and the control group was selected from Isfahan university students (20 male). They walked at self- selected speed at a mean of ten trials (+2) to collect the center of pressure using a force plate. Center of pressure patterns were categorized into four patterns based on the center of pressure displacement magnitude (spatial features) through time (temporal features) when the longitudinal axis of the insole was plotted as the Y- axis and the transverse axis of the insole as X- axis during stance phase. RESULTS: The horizontal angle measured from center of pressure linear regression was positive in the control group (4.6 ± 2.4) (p < 0.005), but negative in the patient group (- 2.3 ± 1.6) (p < 0.005). CONCLUSIONS: The finding of this research measured center of pressure trajectory in steppage gait over time, which is useful for designing better shoe sole and also orthopaedic device and better understanding of stability in patients with drop foot. PMID:21526056

  9. Custom-made different designs of pressure clips for the management of ear lobe keloids

    Directory of Open Access Journals (Sweden)

    Anshul Chugh

    2013-01-01

    Full Text Available Introduction : Keloids are frequent finding after physical trauma. Keloids of ear lobe are common complication of ear piercing, although its incidence remains unknown. The use of intrakeloid resection and a form pressure device to treat pinna keloids. The recommendation of this therapy is to maintain constant pressure and duration of pressure therapy was about 25 weeks. Clinical innovation : This article will present inexpensive custom made pressure clips of various designs. The dimensions of polymethylmethacrylate (PMMA plates in ear lobe clip presented by us though they esthetically not so good, but colored PMMA has been used to make it decorative and acceptable by most of the patients. This has been an encouraging experience to use the different designs. Discussion : Ear clip prosthesis has been developed for maintaining pressure on ear lobe keloids before and after surgical removal. The prosthesis includes an ear clip to which heat-polymerized acrylic resin is attached, which covers the keloid area. Pressure therapy is widely used to help in the early maturation of scar tissue and to prevent the recurrence of keloid. The preliminary report by Brent revealed that constant light pressure was an effective means of preventing post excision recurrence of ear lobe keloids using a decorative, spring-pressure earring.

  10. [Volume fraction of gas vesicle and floating characteristics of cyanobacteria in Taihu Lake under different pressures].

    Science.gov (United States)

    Wang, Wei; Cong, Hai-Bing; Xu, Ya-Jun; Chen, Wen-Jing; Xu, Si-Tao; Wu, Jun; Jiang, Xin-Yue

    2014-08-01

    In order to ascertain the volumetric change of gas vesicles in cyanobacteria and the floating characteristics, capillary pressure method and image analysis method were used to study burst situation and remanent volume fraction of gas vesicles in cyanobacteria under different pressures. The reform situation after pressuring was also analyzed in this research. The results showed that the volume fraction of gas vesicles in Taihu Lake were 29.52%, 5.73%, 4.43%, 2.71%, 2.46%, 2.19% under 0 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa determined by the image analysis, and were 10.93%, 1.14%, 0.90%, 0.27%, 0.14%, 0.04% determined by the capillary pressure method; cyanobacteria sank due to the gas vesicles' bursting when the pressure was greater than 0.4 MPa. Gas vesicles and structure after pressure were reformed with the lapse of time, under 1 000 lx, 25 degrees C, after 8 h, 24 h, 48 h, the reformed gas vesicles accounted for 31.02%, 45.68%, 81.05% of total gas vesicles before pressuring. Image analysis method is more accurate in the determination for cyanobacteria gas vesicles' volume, while the volume is smaller measured by traditional capillary pressure method.

  11. High-Pressure Chemistry of a Zeolitic Imidazolate Framework Compound in the Presence of Different Fluids.

    Science.gov (United States)

    Im, Junhyuck; Yim, Narae; Kim, Jaheon; Vogt, Thomas; Lee, Yongjae

    2016-09-14

    Pressure-dependent structural and chemical changes of the zeolitic imidazolate framework compound ZIF-8 have been investigated using different pressure transmitting media (PTM) up to 4 GPa. The unit cell of ZIF-8 expands and contracts under hydrostatic pressure depending on the solvent molecules used as PTM. When pressurized in water up to 2.2(1) GPa, the unit cell of ZIF-8 reveals a gradual contraction. In contrast, when alcohols are used as PTM, the ZIF-8 unit cell volume initially expands by 1.2% up to 0.3(1) GPa in methanol, and by 1.7% up to 0.6(1) GPa in ethanol. Further pressure increase then leads to a discontinuous second volume expansion by 1.9% at 1.4(1) GPa in methanol and by 0.3% at 2.3(1) GPa in ethanol. The continuous uptake of molecules under pressure, modeled by the residual electron density derived from Rietveld refinements of X-ray powder diffraction, reveals a saturation pressure near 2 GPa. In non-penetrating PTM (silicone oil), ZIF-8 becomes amorphous at 0.9(1) GPa. The structural changes observed in the ZIF-8-PTM system under pressure point to distinct molecular interactions within the pores.

  12. Differences in Activation Area Within Brodmann Area 2 Caused by Pressure Stimuli on Fingers and Joints

    Science.gov (United States)

    Choi, Mi-Hyun; Kim, Hyung-Sik; Baek, Ji-Hye; Lee, Jung-Chul; Park, Sung-Jun; Jeong, Ul-Ho; Gim, Seon-Young; Kim, Sung-Phil; Lim, Dae-Woon; Chung, Soon-Cheol

    2015-01-01

    Abstract In this study, a constant pressure stimulus was applied on the 3 joints (first [p1], second [p2], and third [p3] joints) of 4 fingers (index, middle, ring, and little fingers), and the activation areas within Brodmann area 2 (BA 2) were compared for these different fingers and joints by using functional magnetic resonance imaging. Eight healthy male college students (25.4 ± 1.32 years) participated in the study. Each session was composed of 3 blocks, and each block was composed of a Control phase (30 seconds) and a Pressure phase (30 seconds). No pressure stimulus was applied in the Control phase, during which the subjects would simply lay comfortably with their eyes closed. In the Pressure phase, a pressure stimulus was applied onto one of the joints of the selected finger. For each finger and joint, BA 2 areas activated by the pressure stimulus were extracted by the region of interest method. There was a significant difference in the activation areas for the different fingers (P = .042) as well as for the different joints (P = .050). The activation area decreased in the order of the little, index, and middle fingers, as well as in the order of p1, p3, and p2. PMID:26402840

  13. Influence of the Pressure Difference and Door Swing on Heavy Contaminants Migration between Rooms.

    Science.gov (United States)

    Hendiger, Jacek; Chludzińska, Marta; Ziętek, Piotr

    2016-01-01

    This paper presents the results of investigations whose aim was to describe the influence of the pressure difference level on the ability of contaminants migration between neighbouring rooms in dynamic conditions associated with door swing. The analysis was based on airflow visualization made with cold smoke, which simulated the heavy contaminants. The test room was pressurized to a specific level and then the door was opened to observe the trail of the smoke plume in the plane of the door. The door was opened in both directions: to the positively and negatively pressurized room. This study focuses on the visualization of smoke plume discharge and an uncertainty analysis is not applicable. Unlike other studies which focus on the analysis of pressure difference, the present study looks at the contaminants which are heavier than air and on "pumping out" the contaminants by means of door swing. Setting the proper level of pressure difference between the contaminated room and the neighbouring rooms can prove instrumental in ensuring protection against toxic contaminants migration. This study helped to establish the threshold of pressure difference necessary to reduce migration of heavy contaminants to neighbouring rooms.

  14. Features of blood pressure in student-athletes from different directions of the training process.

    Directory of Open Access Journals (Sweden)

    Kalenichenko Aleksej Vladimirovich

    2011-11-01

    Full Text Available Performed blood pressure (BP and hemodynamics of 85 students: 30 non-athletes (group I, 27 athletes power enforcement types (group II and 28 - endurance sports (group III. It was found that the second and third groups had higher systolic and mean arterial pressure than in the I group. There are differences in blood pressure reactivity to changes in body position, mental and physical activity among the various groups studied. It is shown that the formation of moderate hypertension in group III is carried out by increasing peripheral vascular resistance, and II - at the expense of increased cardiac output.

  15. An experimental investigation of pressurized planar solid oxide fuel cells using two different flow distributors

    Science.gov (United States)

    Chang, H. W.; Huang, C. M.; Shy, S. S.

    2014-03-01

    A high-pressure high-temperature dual-chamber facility is established for electrochemical impedance measurements of pressurized solid oxide fuel cells (PSOFC) to explain why and how the cell performance is increased with increasing pressure (p). By comparing two sets of nearly identical single-cell stacks except using different flow distributors with different degrees of flow uniformity at 850 °C over a range of p varying from 0.1 MPa to 0.5 MPa, we found that the better flow uniformity in flow distributors is, the better the cell performance is, and such performance enhancement is increased with increasing p. This finding is explained by impedance spectra and their associated equivalent circuit models, showing the coupling impact of flow uniformity and pressure elevation to the decrease of ohmic and polarization resistances. These results should be useful to the development of PSOFC integrating with micro gas turbines for future stationary power generation.

  16. Evaluation of the endotracheal tube cuff pressure resulting from four different methods of inflation in dogs.

    Science.gov (United States)

    Briganti, Angela; Portela, Diego A; Barsotti, Giovanni; Romano, Marta; Breghi, Gloria

    2012-09-01

    To evaluate the endotracheal tube cuff pressure achieved by four different inflation methods. Prospective clinical study. Eighty client owned dogs. After anaesthesia induction, endotracheal intubation was performed using plastic or silicone tubes. A clinician unaware of tube type inflated the cuff by simple digital palpation (method A), thereafter the cuff was deflated and inflated again by a second clinician who tried to reproduce a previously learned cuff pressure of between 19 and 24 mmHg (method B). During method C the cuff was inflated to the minimum occlusive volume at an airway pressure of 20 cm H(2) O, and in method D the cuff was incrementally deflated until an audible air leak could be heard from the oral cavity at an airway pressure of 25 cm H(2) O. For all the methods, an operator recorded the actual cuff pressure obtained using a manometer. Heart rate, respiratory rate and mean arterial pressure were monitored throughout the procedure. The mean inflation pressure for plastic tubes was 56 ± 28 mmHg for method A, 20 ± 9 mmHg for method B, 35 ± 32 mmHg for method C and 46 ± 39 mmHg for method D. Pressures using silicone tubes were significantly higher than for plastic tubes, the mean registered pressures being 79 ± 39, 33 ± 16, 77 ± 50 and 92 ± 56 mmHg for methods A, B, C and D. None of the methods evaluated in this study can be considered effective for inflating the endotracheal tube cuff to within the optimal range when using silicone tubes. Direct measurement of the cuff pressure with a manometer is therefore recommended. © 2012 The Authors. Veterinary Anaesthesia and Analgesia. © 2012 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists.

  17. Evaluation of Different Dose-Response Models for High Hydrostatic Pressure Inactivation of Microorganisms.

    Science.gov (United States)

    Buzrul, Sencer

    2017-09-07

    Modeling of microbial inactivation by high hydrostatic pressure (HHP) requires a plot of the log microbial count or survival ratio versus time data under a constant pressure and temperature. However, at low pressure and temperature values, very long holding times are needed to obtain measurable inactivation. Since the time has a significant effect on the cost of HHP processing it may be reasonable to fix the time at an appropriate value and quantify the inactivation with respect to pressure. Such a plot is called dose-response curve and it may be more beneficial than the traditional inactivation modeling since short holding times with different pressure values can be selected and used for the modeling of HHP inactivation. For this purpose, 49 dose-response curves (with at least 4 log 10 reduction and ≥5 data points including the atmospheric pressure value ( P = 0.1 MPa), and with holding time ≤10 min) for HHP inactivation of microorganisms obtained from published studies were fitted with four different models, namely the Discrete model, Shoulder model, Fermi equation, and Weibull model, and the pressure value needed for 5 log 10 ( P ₅) inactivation was calculated for all the models above. The Shoulder model and Fermi equation produced exactly the same parameter and P ₅ values, while the Discrete model produced similar or sometimes the exact same parameter values as the Fermi equation. The Weibull model produced the worst fit (had the lowest adjusted determination coefficient (R² adj ) and highest mean square error (MSE) values), while the Fermi equation had the best fit (the highest R² adj and lowest MSE values). Parameters of the models and also P ₅ values of each model can be useful for the further experimental design of HHP processing and also for the comparison of the pressure resistance of different microorganisms. Further experiments can be done to verify the P ₅ values at given conditions. The procedure given in this study can also be extended

  18. Analysis of wound filter performance from DREF yarn spun at different suction pressure

    Directory of Open Access Journals (Sweden)

    Pragnya S. Kanade

    2017-03-01

    Full Text Available Wound filters are quite popular in the domestic water purification systems. The performance of these filters is based on the distinctive yarn and winding variables. Yarn used for filtration application is normally produced on DREF spinning system. Several researchers have reported the influence of DREF spinning variables on yarn properties. However none of them are in context of filtration application. Since elucidation of influence of winding parameters on the filter performance has already been reported; it thus becomes intriguing to explore the influence of spinning suction pressure on filtration behavior. Yarn spun at different suction pressures was used to produce wound filter cartridges, keeping winding variables unchanged. Filters wound using yarn spun at higher spinning suction pressure resulted in greater pressure drop but showed better micron rating. However the pressure drop encountered also affects the retention capacity of the wound filter. The outcome of this study helps in establishing the relation between spinning suction pressure and performance parameters of wound filters. Design expert® software was used to develop regression equations to predict performance of wound filter for the given spinning suction pressure which is of practical significance for yarn and filter manufacturers, without performing filter test.

  19. The difference in pediatric blood pressure between middle childhood and late childhood prior to dental treatment

    Directory of Open Access Journals (Sweden)

    Fitri Anissa Syaimima bt. Syaiful Azim

    2018-01-01

    Full Text Available Every child will go through several stages in his or her life. They are different from each other as they are in the process of development of cognition, physics, emotion, and personality. For many children, a visit to the dentist can raise their anxiety. This anxiousness will lead to stress that influences the cardiovascular function in the body. The purpose of this research was to determine the difference in pediatric blood pressure between middle childhood and late childhood prior to dental treatment. This research was a clinical trial, pure experimental study. The sample consisted of 30 children within the range of 4-12 years old where they were divided into two groups of age; middle childhood (4-7 years old and late childhood (8-12 years old. The blood pressures were measured before any dental treatment began and the values were recorded. The data were then analyzed using the One-Sample T-Test analysis. The results of blood pressure in middle childhood and late childhood were compared to the average mean values for each age group. It showed that there was a significant difference in the systolic pressure, which was found higher in the middle childhood group compared to the late childhood. From the result can be concluded that there was a difference in the pediatric blood pressure between middle childhood and late childhood prior to dental treatment.

  20. Tongue Pressure Modulation for Initial Gel Consistency in a Different Oral Strategy

    Science.gov (United States)

    Yokoyama, Sumiko; Hori, Kazuhiro; Tamine, Ken-ichi; Fujiwara, Shigehiro; Inoue, Makoto; Maeda, Yoshinobu; Funami, Takahiro; Ishihara, Sayaka; Ono, Takahiro

    2014-01-01

    Background In the recent hyper-aged societies of developed countries, the market for soft diets for patients with dysphagia has been growing and numerous jelly-type foods have become available. However, interrelationships between the biomechanics of oral strategies and jelly texture remain unclear. The present study investigated the influence of the initial consistency of jelly on tongue motor kinetics in different oral strategies by measuring tongue pressure against the hard palate. Methods Jellies created as a mixture of deacylated gellan gum and psyllium seed gum with different initial consistencies (hard, medium or soft) were prepared as test foods. Tongue pressure production while ingesting 5 ml of jelly using different oral strategies (Squeezing or Mastication) was recorded in eight healthy volunteers using an ultra-thin sensor sheet system. Maximal magnitude, duration and total integrated values (tongue work) of tongue pressure for size reduction and swallowing in each strategy were compared among initial consistencies of jelly, and between Squeezing and Mastication. Results In Squeezing, the tongue performed more work for size reduction with increasing initial consistency of jelly by modulating both the magnitude and duration of tongue pressure over a wide area of hard palate, but tongue work for swallowing increased at the posterior-median and circumferential parts by modulating only the magnitude of tongue pressure. Conversely, in Mastication, the tongue performed more work for size reduction with increasing initial consistency of jelly by modulating both magnitude and duration of tongue pressure mainly at the posterior part of the hard palate, but tongue work as well as other tongue pressure parameters for swallowing showed no differences by type of jelly. Conclusions These results reveal fine modulations in tongue-palate contact according to the initial consistency of jelly and oral strategies. PMID:24643054

  1. Comparison of plantar pressure distribution between three different shoes and three common movements in futsal.

    Directory of Open Access Journals (Sweden)

    Meghdad Teymouri

    Full Text Available Analysis of in-shoe pressure distribution during sport-specific movements may provide a clue to improve shoe design and prevent injuries. This study compared the mean and the peak pressures over the whole foot and ten separate areas of the foot, wearing different shoes during specific movements.Nine male adult recreational futsal players performed three trials of three sport-specific movements (shuffle, sprint and penalty kick, while they were wearing three brands of futsal shoes (Adidas, Lotto and Tiger. Plantar pressures on dominant feet were collected using the F-SCAN system. Peak and mean pressures for whole foot and each separate area were extracted. For statistical analysis, the mean differences in outcome variables between different shoes and movements were estimated using random-effects regression model using STATA ver.10.In the average calculation of the three movements, the peak pressure on the whole foot in Adidas shoe was less than Lotto [8.8% (CI95%: 4.1-13.6%] and Tiger shoes [11.8% (CI95%:7-16.7%], (P<0.001. Also, the recorded peak pressure on the whole foot in penalty kick was 61.1% (CI95%: 56.3-65.9% and 57.6% (CI95%: 52.8-62.3% less than Shuffle and Sprint tests, respectively (P<0.001.Areas with the highest peak pressure during all 3 movements were not different between all shoes. This area was medial forefoot in cases of shuffle and sprint movements and medial heel in case of penalty kick.

  2. Comparison of plantar pressure distribution between three different shoes and three common movements in futsal.

    Science.gov (United States)

    Teymouri, Meghdad; Halabchi, Farzin; Mirshahi, Maryam; Mansournia, Mohammad Ali; Mousavi Ahranjani, Ali; Sadeghi, Amir

    2017-01-01

    Analysis of in-shoe pressure distribution during sport-specific movements may provide a clue to improve shoe design and prevent injuries. This study compared the mean and the peak pressures over the whole foot and ten separate areas of the foot, wearing different shoes during specific movements. Nine male adult recreational futsal players performed three trials of three sport-specific movements (shuffle, sprint and penalty kick), while they were wearing three brands of futsal shoes (Adidas, Lotto and Tiger). Plantar pressures on dominant feet were collected using the F-SCAN system. Peak and mean pressures for whole foot and each separate area were extracted. For statistical analysis, the mean differences in outcome variables between different shoes and movements were estimated using random-effects regression model using STATA ver.10. In the average calculation of the three movements, the peak pressure on the whole foot in Adidas shoe was less than Lotto [8.8% (CI95%: 4.1-13.6%)] and Tiger shoes [11.8% (CI95%:7-16.7%)], (P<0.001). Also, the recorded peak pressure on the whole foot in penalty kick was 61.1% (CI95%: 56.3-65.9%) and 57.6% (CI95%: 52.8-62.3%) less than Shuffle and Sprint tests, respectively (P<0.001). Areas with the highest peak pressure during all 3 movements were not different between all shoes. This area was medial forefoot in cases of shuffle and sprint movements and medial heel in case of penalty kick.

  3. Differing chemical compositions of three teas may explain their different effects on acute blood pressure in spontaneously hypertensive rats.

    Science.gov (United States)

    Li, Shan-Bing; Li, Yi-Fang; Mao, Zhong-Fu; Hu, Hui-Hua; Ouyang, Shu-Hua; Wu, Yan-Ping; Tsoi, Bun; Gong, Pin; Kurihara, Hiroshi; He, Rong-Rong

    2015-04-01

    Heavy tea consumption is suggested to be unsuitable for hypertensive people. However, the bioactive substances in different varieties of tea leaves are very different. This study compares the effects of three Chinese teas - C. sinensis, C. ptilophylla and C. assamica var. kucha - on blood pressure (BP) and heart rate in spontaneously hypertensive rats (SHRs). Intragastric administration of C. sinensis extract led to an acute increase in systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate in SHRs. However, C. ptilophylla and C. assamica var. kucha exerted no obvious influences on SBP, DBP or heart rate. Similar to the extract of C. sinensis, intragastric administration of caffeine also led to an acute increase in BP and heart rate in SHRs. In contrast, theobromine and theacrine - purine alkaloids predominantly contained in C. ptilophylla and C. assamica var. kucha, respectively - had no pressor effects. The effect of caffeine on BP was related to the regulation of plasma epinephrine and norepinephrine levels in SHRs. The different effects of C. sinensis, C. ptilophylla and C. assamica var. kucha on BP might be explained, at least partially, by the differences in the varieties and contents of purine alkaloids. © 2014 Society of Chemical Industry.

  4. Pressure differences between over-pressured sands and bounding shales of the Eugene island 330 field (offshore Louisiana, USA) with implications for fluid flow induced by sediment loading

    Energy Technology Data Exchange (ETDEWEB)

    Stump, B.B.; Flemings, P.B. [Pennsylvania Univ., Philadelphia, PA (United States); Finkbeiner, Th.; Zoback, M.D. [Stanford Univ., Dept. of Geophysics, CA (United States)

    1999-04-01

    We document pressure differences between adjacent sands and shales in geopressured Plio-Pleistocene strata of offshore Louisiana and we quantify a sediment loading model that describes the origin of these differences. The JD sand is in moderate geo-pressure (P{sub f}/{sigma}{sub 1} = 0.6) and has a lower pressure than its bounding shale. The L1 sand is severely over-pressured (P{sub f}/{sigma}{sub 1} = 0.9) and has a pressure greater than its bounding shale. Shales which are adjacent to the JD and L1 sands have pressures (derived from a porosity-effective stress relationship) which follow a litho-static gradient. We interpret this behaviour to result from rapid, spatially varying loading of permeable sand bodies by relatively impermeable shales. Under these conditions. pore pressures at the peak of structure can significantly exceed the pore pressure of bounding shales. The L1 sand records this behaviour. In contrast, the low relative pressures in the JD sand may record dissipation of pressure by fluid migration along permeable pathways. The sediment loading model predicts along-stratal flow within sands and cross-stratal flow at structural highs. In a companion paper. FINKBEINER et al. (this volume) describe how sediment loading and the buoyant effect of hydrocarbons combine to drive sand pressures toward the minimum principal stress of bounding cap rocks, resulting in fluid migration. (author)

  5. High voltage tests of an electrostatic accelerator for different mixtures of gases at various pressures

    International Nuclear Information System (INIS)

    Hellborg, R.

    1996-01-01

    An account is given of high voltage tests of an electrostatic accelerator. High voltage conditioning is measured and is reported for the same accelerator tube after different periods of usage. Tests of different mixtures of sulphur hexafluoride and nitrogen have been performed. A considerable amount of data was obtained for various parameters connected with the high voltage system for different proportions of nitrogen in sulphur hexafluoride at various gas pressures. (orig.)

  6. Diastolic Pressure Difference to Classify Pulmonary Hypertension in the Assessment of Heart Transplant Candidates.

    Science.gov (United States)

    Wright, Stephen P; Moayedi, Yasbanoo; Foroutan, Farid; Agarwal, Suhail; Paradero, Geraldine; Alba, Ana C; Baumwol, Jay; Mak, Susanna

    2017-09-01

    The diastolic pressure difference (DPD) is recommended to differentiate between isolated postcapillary and combined pre-/postcapillary pulmonary hypertension (Cpc-PH) in left heart disease (PH-LHD). However, in usual practice, negative DPD values are commonly calculated, potentially related to the use of mean pulmonary artery wedge pressure (PAWP). We used the ECG to gate late-diastolic PAWP measurements. We examined the method's impact on calculated DPD, PH-LHD subclassification, hemodynamic profiles, and mortality. We studied patients with advanced heart failure undergoing right heart catheterization to assess cardiac transplantation candidacy (N=141). Pressure tracings were analyzed offline over 8 to 10 beat intervals. Diastolic pulmonary artery pressure and mean PAWP were measured to calculate the DPD as per usual practice (diastolic pulmonary artery pressure-mean PAWP). Within the same intervals, PAWP was measured gated to the ECG QRS complex to calculate the QRS-gated DPD (diastolic pulmonary artery pressure-QRS-gated PAWP). Outcomes occurring within 1 year were collected retrospectively from chart review. Overall, 72 of 141 cases demonstrated PH-LHD. Within PH-LHD, the QRS-gated DPD yielded higher calculated DPD values (3 [-1 to 6] versus 0 [-4 to 3] mm Hg; P pulmonary hypertension ( P pulmonary hypertension. The QRS-gated DPD reclassifies a subset of PH-LHD patients from isolated postcapillary pulmonary hypertension to Cpc-PH, which is characterized by an adverse hemodynamic profile. © 2017 American Heart Association, Inc.

  7. Low-pressure reversible axial fan designed with different specific work of elementary stages

    Directory of Open Access Journals (Sweden)

    Bogdanović Božidar P.

    2012-01-01

    Full Text Available Low-pressure axial fan impellers designed according to the principle of equal specific work of all elementary stages have blades whose profile near the fan hub is under a significantly larger inclination angle than at the impeller periphery. In order to minimize the spatial curvature of the fan blades and the fan hub length, impeller blades of low-pressure axial fans can be designed with different specific work of elementary stages, so that the specific work of elementary stages is smaller at the hub than at the periphery. This paper presents the operating characteristics of a low-pressure reversible axial fan with straight blade profiles, designed with different specific work of elementary stages. The fan was tested on a standard test rig, with air intake loading on the suction side of the fan.

  8. An ex vivo porcine skin model to evaluate pressure-reducing devices of different mechanical properties used for pressure ulcer prevention.

    Science.gov (United States)

    Yeung, Ching-Yan C; Holmes, David F; Thomason, Helen A; Stephenson, Christian; Derby, Brian; Hardman, Matthew J

    2016-11-01

    Pressure ulcers are complex wounds caused by pressure- and shear-induced trauma to skin and underlying tissues. Pressure-reducing devices, such as dressings, have been shown to successfully reduce pressure ulcer incidence, when used in adjunct to pressure ulcer preventative care. While pressure-reducing devices are available in a range of materials, with differing mechanical properties, understanding of how a material's mechanical properties will influence clinical efficacy remains limited. The aim of this study was to establish a standardized ex vivo model to allow comparison of the cell protection potential of two gel-like pressure-reducing devices with differing mechanical properties (elastic moduli of 77 vs. 35 kPa). The devices also displayed differing energy dissipation under compressive loading, and resisted strain differently under constant load in compressive creep tests. To evaluate biological efficacy we employed a new ex vivo porcine skin model, with a confirmed elastic moduli closely matching that of human skin (113 vs. 119 kPa, respectively). Static loads up to 20 kPa were applied to porcine skin ex vivo with subsequent evaluation of pressure-induced cell death and cytokine release. Pressure application alone increased the percentage of epidermal apoptotic cells from less than 2% to over 40%, and increased cellular secretion of the pro-inflammatory cytokine TNF-alpha. Co-application of a pressure-reducing device significantly reduced both cellular apoptosis and cytokine production, protecting against cellular damage. These data reveal new insight into the relationship between mechanical properties of pressure-reducing devices and their biological effects. After appropriate validation of these results in clinical pressure ulcer prevention with all tissue layers present between the bony prominence and external surface, this ex vivo porcine skin model could be widely employed to optimize design and evaluation of devices aimed at reducing pressure

  9. Association between body size and blood pressure in children from different ethnic origins

    Directory of Open Access Journals (Sweden)

    LA de Hoog Marieke

    2012-11-01

    Full Text Available Abstract Objective To assess associations between body size and blood pressure in children (5-6 years from different ethnic origins. Method Five ethnic groups of the ABCD cohort were examined: Dutch (n=1 923, Turkish (n=99, Moroccan (n=187, Black-African (n=67 and Black-Caribbean (n=121. Data on body-mass-index (BMI, waist-to-height ratio (WHtR, fat-mass-index (FMI, and systolic blood pressure (SBP and diastolic blood pressure (DBP, were collected. Linear regression analysis with restricted cubic splines was used to examine non-linear associations between body size and blood pressure, adjusted for age, sex, height and birth weight. Results Ethnic differences were found in associations of BMI with SBP and DBP (SBP: p=0.001 and DBP: p=0.01 and FMI with SBP (p=0.03. BMI and FMI had a relatively large positive association with SBP in Turkish children (BMI: β=2.46mmHg; 95%CI:1.20-3.72; FMI: β=2.41mmHg; 95%CI:1.09-3.73 compared to Dutch (BMI: β=1.31mmHg; 95%CI:0.71-1.92; FMI: β=0.84mmHg; 95%CI:0.23-1.45. Black-Caribbean and Moroccan children showed high blood pressure with low BMI and FMI. Moroccan children showed higher SBP with high BMI and FMI. WHtR was positively associated with SBP and DBP, similar in all ethnic groups. Generally, strongest associations with blood pressure were found for BMI in all ethnic groups. Conclusion Ethnic-specific associations between BMI, and FMI and blood pressure are present at young age, with Turkish children showing the highest increase in blood pressure with increasing body size. The higher blood pressure in the Black-Caribbean and Moroccan children with low BMI needs further research. WHtR or FMI do not seem to be associated more strongly to blood pressure than BMI in any ethnic group.

  10. Variation of Compton Profiles of the CO2 at different pressures

    Science.gov (United States)

    Gürol, Ali; Şakar, Erdem

    2017-04-01

    In this study, it has been measured the Compton Profile of the CO2 gas at different pressures by using a Compton Profile Spectrometer with an annular Am-241 radioactive source and a HPGe detector. CO2 gas molecules sealed in a gas chamber at different pressures. The gas pressure had been set by using an analog manometer before the measurements. The γ-rays emitted from source was incident into the gas from a hostaphan window. The detector recorded the scattered photons from molecules. To obtain correct Compton Profile values, the raw data were corrected for some effects; i.e. scattering from the gas chamber's walls, absorption effects of windows on gas chamber and detector, and multiple scattering corrections. A Matlab Code has been used for all calculations. The results clearly demonstrate the valance electronic structure of the materials is highly depending on the pressure. According to our experimental results, when the pressure in the gas chamber increase the Compton Profiles of valance electrons changes ˜ 8,0%.

  11. Microbial quality of soil from the Pampa biome in response to different grazing pressures

    Directory of Open Access Journals (Sweden)

    Rafael S. Vargas

    2015-06-01

    Full Text Available The aim of this study was to evaluate the impact of different grazing pressures on the activity and diversity of soil bacteria. We performed a long-term experiment in Eldorado do Sul, southern Brazil, that assessed three levels of grazing pressure: high pressure (HP, with 4% herbage allowance (HA, moderate pressure (MP, with 12% HA, and low pressure (LP, with 16% HA. Two reference areas were also assessed, one of never-grazed native vegetation (NG and another of regenerated vegetation after two years of grazing (RG. Soil samples were evaluated for microbial biomass and enzymatic (β-glucosidase, arylsulfatase and urease activities. The structure of the bacterial community and the population of diazotrophic bacteria were evaluated by RFLP of the 16S rRNA and nifH genes, respectively. The diversity of diazotrophic bacteria was assessed by partial sequencing of the 16S rDNA gene. The presence of grazing animals increased soil microbial biomass in MP and HP. The structures of the bacterial community and the populations of diazotrophic bacteria were altered by the different grazing managements, with a greater diversity of diazotrophic bacteria in the LP treatment. Based on the characteristics evaluated, the MP treatment was the most appropriate for animal production and conservation of the Pampa biome.

  12. Performance of PrekotAC Filter Aids on Pressure Drop across Two Different Filter Media

    Directory of Open Access Journals (Sweden)

    Hajar S.

    2017-01-01

    Full Text Available A study on the performance of formulated PrekotAC filter aids on pressure drop across two different types of filter media, i.e polytetrafluoroethylene (PTFE and polyimide (P84 was carried out in a laboratory scale fabric filtration system. Filter aids is applied in order to prolong the lifespan of the fabric filter by reducing the pressure drop across a filter cake. PrekotAC which is a combination of 90%wt activated carbon and 10%wt PreKotTM was tested under various material loadings of 0.2, 0.4, and 0.6 mg/mm2 at a constant filtration velocity of 5 m/min across its cake and filter media. The results showed that PrekotAC presents a lower pressure drop across the P84 compared to PTFE filter media under various material loadings. This is because of its different characteristics that effect the porosity of the filter media and allow a higher volumetric airflow passing through, resulting in lower pressure drop compared to PTFE filter media. In addition, the diversity in terms of particle size distribution of the formulated PrekotAC that increase its permeability property helps to reduce the pressure drop across the media and its filter cake. Thus, PrekotAC has a promising characteristic as a two in one filter aids, a pre-coating and adsorbent material for fabric filtration system.

  13. Application of vacuum-assisted closure in seawater-immersed wound treatment under different negative pressures.

    Science.gov (United States)

    Cao, L; Peng, M M; Sun, J J; Yu, X C; Shi, B

    2015-06-11

    The therapeutic effect of vacuum-assisted closure (VAC) has been confirmed in many types of complex wounds, but there are few relevant reports regarding seawater-immersed wounds. The aim of this study was to determine the effect of VAC on seawater-immersed wound healing under different negative pressures and explore the optimal negative pressure value. Four purebred miniature pigs were used as the experimental animal models. Four acute, symmetrical wounds were made on each side of the spine and designated as the experimental group (wounds with 2 h of seawater immersion) and the control group (wounds without seawater immersion). Wounds were divided into a conventional dressing group and 3 further groups with different VAC therapies (negative pressure at either 120, 180, or 240 mmHg). The extent of wound healing, and speed of granulation growth and re-epithelialization were measured. Bacterial flora distribution in the wounds was observed, and fibronectin levels in the exudate of the wounds were tested. Results showed that seawater immersion aggravated wound injury and that VAC therapy with 180 mmHg negative pressure induced the fastest epidermis migration, obvious edema elimination, significant capillary proliferation, and the highest level of fibronectin, and that in wounds, the proportion of Gram-negative bacteria tended to decrease and that of Gram-positive bacteria tended to increase. Our results show that VAC promotes seawater-immersed wound healing and that 180 mmHg negative pressure may be optimal for wound healing.

  14. Differences in blood pressure by measurement technique in neurocritically ill patients: A technological assessment.

    Science.gov (United States)

    Lele, Abhijit V; Wilson, Daren; Chalise, Prabhakar; Nazzaro, Jules; Krishnamoorthy, Vijay; Vavilala, Monica S

    2018-01-01

    Blood pressure data may vary by measurement technique. We performed a technological assessment of differences in blood pressure measurement between non-invasive blood pressure (NIBP) and invasive arterial blood pressure (ABP) in neurocritically ill patients. After IRB approval, a prospective observational study was performed to study differences in systolic blood pressure (SBP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) values measured by NIBP arm, ABP at level of the phlebostatic axis (ABP heart) and ABP at level of the external auditory meatus (ABP brain) at 30 and 45-degree head of bed elevation (HOB) using repeated measure analysis of covariance and correlation coefficients. Overall, 168 patients were studied with median age of 57 ± 15 years, were mostly female (57%), with body mass index ≤30 (66%). Twenty-three percent (n = 39) had indwelling intracranial pressure monitors, and 19.7% (n = 33) received vasoactive agents. ABP heart overestimated ABP brain for SBP (11.5 ± 2.7 mmHg, p < .001), MAP (mean difference 13.3 ± 0.5 mmHg, p < .001) and CPP (13.4 ± 3.2 mmHg, p < .001). ABP heart overestimated NIBP arm for SBP (8 ± 1.5 mmHg, p < .001), MAP (mean difference 8.6 ± 0.8 mmHg, p < .001), and CPP (mean difference 9.8 ± 3.2 mmHg, p < .001). Regardless of HOB elevation, ABP heart overestimates MAP compared to ABP brain and NIBP arm. Using ABP heart data overestimates CPP and may be responsible for not achieving SBP, MAP or CPP targets aimed at the brain. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. [Practices and effects of different measures for blood pressure control in hypertension patients in Beijing, 2014].

    Science.gov (United States)

    Li, H; Dong, Z; Ma, A J; Dong, J; Fang, K; Xie, C; Qi, K; Xie, J; Zhou, Y; Zhao, Y

    2016-09-10

    Objective: To understand the practices and effects of different measures for blood pressure control in hypertension patients. Methods: Patients who have known hypertension from the subjects of "2014 Beijing adult (aged 18-79 years) chronic diseases and risk factors survey" were selected. The choices of different hypertension control measures, the relationship between the measures and demographic characteristics of hypertension patients, and the effects of different control measures were analyzed. Results: A total of 2 229 known hypertension patients were included, the analysis was conducted through a questionnaire survey. Those who answered "never taking any measures" , "taking medication according to doctor's instructions" and "taking medication when blood pressure rose" accounted for 7.0%, 79.8% and 8.3%, respectively. Those who had "diet control" , "physical exercises" and "blood pressure monitoring" accounted for 22.4%, 23.7% and 22.1%, respectively. In terms of "taking medicine according to doctor's instructions" , women (84.3%), those aged ≥60 years (87.6%), those living in urban area (81.5%), those living alone (83.8%), and Beijing local residents (82.3%) had higher compliance rates. As for "diet control" , women (24.4%), those aged ≥60 years (25.8%) and those with educational level of college or above (29.5%) had better practices. In terms of "physical exercise" , those aged ≥60 years (27.9%), those living in urban area (25.3%), those with educational level of college or above (32.5%) had better practice. Women (24.2%) and those aged ≥60 years (28.4%) had higher "blood pressure monitoring" rate. More men (9.7%), those aged 18-44 years (14.7%), those with educational level of high school (9.3%), the unmarried (18.2%), and non-Beijing local residents (14.7%) answered "never taking any measure" , and in terms of "taking medication when blood pressure rose" , non-Beijing local residents (12.8%) had higher rate. In the field survey, more patients who

  16. Thermodynamics of the multicomponent vapor-liquid equilibrium under capillary pressure difference

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    2001-01-01

    algorithms of flash calculations in order to solve these problems. Sample calculations show large variation of the capillary properties of the mixture in the very neighborhood of the phase envelope and the restrictive role of the spinodal surface as a boundary for possible equilibrium states with different...... pressures. (C) 2001 Elsevier Science B.V. All rights reserved....

  17. Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices.

    Science.gov (United States)

    Monnet, Xavier; Anguel, Nadia; Naudin, Brice; Jabot, Julien; Richard, Christian; Teboul, Jean-Louis

    2010-01-01

    We compared the ability of two devices estimating cardiac output from arterial pressure-curve analysis to track the changes in cardiac output measured with transpulmonary thermodilution induced by volume expansion and norepinephrine in sepsis patients. In 80 patients with septic circulatory failure, we administered volume expansion (40 patients) or introduced/increased norepinephrine (40 patients). We measured the pulse contour-derived cardiac index (CI) provided by the PiCCO device (CIpc), the arterial pressure waveform-derived CI provided by the Vigileo device (CIpw), and the transpulmonary thermodilution CI (CItd) before and after therapeutic interventions. The changes in CIpc accurately tracked the changes in CItd induced by volume expansion (bias, -0.20 +/- 0.63 L/min/m2) as well as by norepinephrine (bias, -0.05 +/- 0.74 L/min/m2). The changes in CIpc accurately detected an increase in CItd >or= 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.878 (0.736 to 0.960) and 0.924 (0.795 to 0.983), respectively; P or= 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.564 (0.398 to 0.720) and 0.541 (0.377 to 0.700, respectively, both not significantly different from versus 0.500). The CIpc was reliable and accurate for assessing the CI changes induced by volume expansion and norepinephrine. By contrast, the CIpw poorly tracked the trends in CI induced by those therapeutic interventions.

  18. Compositional Differences of Ojeok-san (Wuji-san Decoctions Using Pressurized or Non-pressurized Methods for Variable Extraction Times

    Directory of Open Access Journals (Sweden)

    Kim Jung-Hoon

    2012-06-01

    Full Text Available This study compared Ojeok-san (Wuji-san in Chinese decoctions produced using different extraction methods for variable times. Decoctions were extracted in pressurized or non-pressurized conditions for 60, 120, and 180 mins. We investigated the Ojeok-san extract yield, the total soluble solid content, the hydrogen ion concentration (pH, and the reference compound content. The extract yield and the total soluble solid content were higher in decoctions produced by non-pressurized extraction; both were proportional to the extraction time. The pH tended to decrease as the extraction time was increased in decoctions produced using both methods. After 60 and 180 mins, the levels of albiflorin, paeoniflorin, nodakenin, naringin, and neohesperidin were significantly higher in decoctions extracted using the non-pressurized method compared with those extracted using the pressurized method. After 120 mins, only cinnamaldehyde was extracted in a greater amount in pressurized decoctions compared with non-pressurized decoctions. The levels of paeoniflorin, ferulic acid, nodakenin, naringin, hesperidin, neohesperidin, and glycyrrhizin increased with time in non-pressurized decoctions. This study showed that the use of pressurized and non-pressurized extraction methods for different times affected the composition of Ojeoksan (Wuji-san decoctions.

  19. Comparison between the volumetric flow rate and pressure distribution for different kinds of sliding thrust bearing

    Directory of Open Access Journals (Sweden)

    O. Pourmehran

    2015-06-01

    Full Text Available In this paper a hydrodynamic journal sliding bearing, forming with two nonparallel surfaces that the lower surface moves with a unidirectional velocity and the upper surface is stationary shaped with exponential geometry is verified mathematically. The values of volumetric flow rate and distribution of pressure for incompressible lubricant flow between two supports in several conditions of velocity with different variables are determined. The results indicate that by increasing the amount of constant (m, the maximum oil pressure in the bearing will face an extreme decrease, and also by increasing the α coefficient, the rate of volumetric flow rate will decrease.

  20. Ethnic differences in the effects of the DASH diet on nocturnal blood pressure dipping in individuals with high blood pressure.

    Science.gov (United States)

    Prather, Aric A; Blumenthal, James A; Hinderliter, Alan L; Sherwood, Andrew

    2011-12-01

    Ethnic differences in nocturnal blood pressure (BP) dipping may contribute to the increased risk for adverse cardiovascular events noted in African Americans (AAs). The DASH (Dietary Approaches to Stop Hypertension) diet has been shown to be efficacious in lowering clinic and ambulatory BP; however, the effect of the DASH diet on BP dipping is unclear. One hundred and eighteen men and women with high clinic BP (systolic BP (SBP) 130-159; diastolic BP 85-99) and above ideal body weight were randomized to a DASH diet intervention or to a usual diet control (UC) condition. Measures of 24-h ambulatory BP were obtained at baseline and at the end of the 4-month intervention period. At baseline, AAs (n = 43) displayed blunted nocturnal SBP dipping compared to Caucasians (CAs; n = 75) and were more likely to be categorized as nondippers (DASH diet intervention showed a significant improvement in SBP dipping postintervention compared to AAs in the UC condition (P = 0.04), whereas there was no appreciable change in SBP dipping in CAs (P = 0.72). Following the intervention, ethnic differences in SBP dipping were no longer statistically significant (nondipper status: AAs: 44% vs. CAs: 32%; P = 0.19). Our study provides preliminary evidence suggesting that in overweight men and women with high BP, AAs may be especially likely to benefit from augmented SBP dipping associated with consumption of the DASH diet.

  1. Clinic Versus Daytime Ambulatory Blood Pressure Difference in Hypertensive Patients: The Impact of Age and Clinic Blood Pressure.

    Science.gov (United States)

    Banegas, José R; Ruilope, Luis M; de la Sierra, Alejandro; Vinyoles, Ernest; Gorostidi, Manuel; de la Cruz, Juan J; Segura, Julián; Oliveras, Anna; Martell, Nieves; García-Puig, Juan; Williams, Bryan

    2017-02-01

    Clinic blood pressure (BP) is usually higher than daytime ambulatory BP in hypertensive patients, but some recent studies have challenged this view, suggesting that this relationship is strongly influenced by age. We used the Spanish ambulatory BP monitoring cohort to examine differences between clinic and daytime BP by age among 104 639 adult hypertensive patients (office systolic/diastolic BP ≥140/90 mm Hg or treated) in usual primary-care practice, across the wide age spectrum. To assess the impact of age, cardiovascular variables, and clinic BP on the clinic-daytime BP differences, we built multivariable regression models of the average BP differences, white-coat hypertension (high clinic BP and normal daytime BP), and masked hypertension (normal clinic BP and high daytime BP). In most patients, mean clinic BP values were higher than daytime BP at all ages. Some 36.7% of patients had white-coat hypertension (amounting to 50% at clinic systolic BP of 140-159 mm Hg) and 3.9% had masked hypertension (amounting to 18% at clinic systolic BP of 130-139 mm Hg). Age explained 0.1% to 1.7% of the variance of quantitative or categorical BP differences (Phypertension status in >40% of patients. This misclassification was not importantly influenced by age but was more evident in patients with borderline/grade 1 hypertension. These findings reinforce the importance of ambulatory BP monitoring for defining BP status in routine clinical practice. © 2017 American Heart Association, Inc.

  2. [Comparison of different continuous positive airway pressure titration methods for obstructive sleep apnea hypopnea syndrome].

    Science.gov (United States)

    Li, Jingjing; Ye, Jingying; Zhang, Peng; Kang, Dan; Cao, Xin; Zhang, Yuhuan; Ding, Xiu; Zheng, Li; Li, Hongguang; Bian, Qiuli

    2014-10-01

    To explore whether there were differences between the results of automatic titration and the results of manual titration for positive airway pressure treatment in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and its influencing factors, the results might provide a theoretical basis for the rational use of two pressure titration methods. Sixty one patients with OSAHS were included in this study. All patients underwent a manual titration and an automatic titration within one week. The clinical informations, polysomnography data, and the results of both two titration of all patients were obtained for analysis. The overall apnea/hypopnea index was (63.1 ± 17.7)/h, with a range of 14.9/h to 110.4/h. The treatment pressure of manual titration was (8.4 ± 2.1) cmH(2)O, which was significantly lower than the treatment pressure of automatic titration, (11.5 ± 2.7) cmH(2)O (t = -9.797, P titration and manual titration), it was found that the pressure of automatic titration was significantly higher in patients with a ΔP > 3 cmH(2)O than in patients with a ΔP ≤ 3 cmH(2)O, which was (13.3 ± 2.3) cmH(2)O vs (10.0 ± 2.0) cmH(2)O (t = -6.159, P titration between these two groups, which was (8.6 ± 2.4) cmH(2)O vs (8.3 ± 2.0)cmH(2)O (P > 0.05). There was no significant difference in age, body mass index, neck circumference, abdomen circumference, apnea hypopnea index, and arterial oxygen saturation between these two groups. The treatment pressure of automatic titration is usually higher than that of manual titration. For patients with a high treatment pressure which is derived from automatic titration, a suggestion about manual titration could be given to decrease the potential treatment pressure of continuous positive airway pressure, which may be helpful in improving the comfortableness and the compliance of this treatment.

  3. Pressure- and flow-controlled media perfusion differently modify vascular mechanics in lung decellularization.

    Science.gov (United States)

    da Palma, Renata K; Campillo, Noelia; Uriarte, Juan J; Oliveira, Luis V F; Navajas, Daniel; Farré, Ramon

    2015-09-01

    Organ biofabrication is a potential future alternative for obtaining viable organs for transplantation. Achieving intact scaffolds to be recellularized is a key step in lung bioengineering. Perfusion of decellularizing media through the pulmonary artery has shown to be effective. How vascular perfusion pressure and flow vary throughout lung decellularization, which is not well known, is important for optimizing the process (minimizing time) while ensuring scaffold integrity (no barotrauma). This work was aimed at characterizing the pressure/flow relationship at the pulmonary vasculature and at how effective vascular resistance depends on pressure- and flow-controlled variables when applying different methods of media perfusion for lung decellularization. Lungs from 43 healthy mice (C57BL/6; 7-8 weeks old) were investigated. After excision and tracheal cannulation, lungs were inflated at 10 cmH2O airway pressure and subjected to conventional decellularization with a solution of 1% sodium dodecyl sulfate (SDS). Pressure (PPA) and flow (V'PA) at the pulmonary artery were continuously measured. Decellularization media was perfused through the pulmonary artery: (a) at constant PPA=20 cmH2O or (b) at constant V'PA=0.5 and 0.2 ml/min. Effective vascular resistance was computed as Rv=PPA/V'PA. Rv (in cmH2O/(ml/min)); mean±SE) considerably varied throughout lung decellularization, particularly for pressure-controlled perfusion (from 29.1±3.0 in baseline to a maximum of 664.1±164.3 (pmechanics throughout decellularization provides information relevant for optimizing the process time while ensuring that vascular pressure is kept within a safety range to preserve the organ scaffold integrity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. The Difference in Translaminar Pressure Gradient and Neuroretinal Rim Area in Glaucoma and Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Lina Siaudvytyte

    2014-01-01

    Full Text Available Purpose. To assess differences in translaminar pressure gradient (TPG and neuroretinal rim area (NRA in patients with normal tension glaucoma (NTG, high tension glaucoma (HTG, and healthy controls. Methods. 27 patients with NTG, HTG, and healthy controls were included in the prospective pilot study (each group consisted of 9 patients. Intraocular pressure (IOP, intracranial pressure (ICP, and confocal laser scanning tomography were assessed. TPG was calculated as the difference of IOP minus ICP. ICP was measured using noninvasive two-depth transcranial Doppler device. The level of significance P 0.05. The difference between TPG for healthy (5.4(7.7 mmHg and glaucomatous eyes (NTG 6.3(3.1 mmHg, HTG 15.7(7.7 mmHg was statistically significant (P < 0.001. Higher TPG was correlated with decreased NRA (r = −0.83; P = 0.01 in the NTG group. Conclusion. Translaminar pressure gradient was higher in glaucoma patients. Reduction of NRA was related to higher TPG in NTG patients. Further prospective studies are warranted to investigate the involvement of TPG in glaucoma management.

  5. Positron annihilation spectroscopy studies of bronze exposed to sandblasting at different pressure

    Science.gov (United States)

    Kurdyumov, S.; Siemek, K.; Horodek, P.

    2017-11-01

    An application of Doppler broadening of annihilation line spectroscopy to samples of beryllium bronze DIN-CuBe2 exposed to sandblasting is presented in performed studies. It is familiar that sandblasting introduces open-volume defects. Samples were sandblasted under different pressure for 1 minute using 110 μm particles of Al2O3. For a non-defected sample the constant value of S-parameter was detected. In the cases of sandblasted samples, S-parameter decreased when the depth enhanced. In our studies the thicknesses of defected zones were determined (it was c.a. 30 μm for a sample blasted under pressure of 1 bar and 110 μm – for 5 bar), and it was also observed that if sandblasting pressure is higher the defected zone is larger.

  6. Effect of different frequencies of music on blood pressure regulation in spontaneously hypertensive rats.

    Science.gov (United States)

    Akiyama, Kayo; Sutoo, Den'etsu

    2011-01-03

    The effect of different frequencies of music on brain function was investigated through measurement of blood pressure in spontaneously hypertensive rats (SHR). Previous studies indicated that exposure to Mozart's music (K. 205) leads to increased calcium/calmodulin-dependent dopamine synthesis in the brain, and that the subsequent increase in dopamine reduces blood pressure via D(2) receptors. The present study demonstrated that the blood pressure-reducing response was dependent on the frequency, and was markedly greater at 4 k-16 kHz compared with lower frequencies. These findings suggest that music containing high-frequency sounds stimulates dopamine synthesis, and might thereby regulate and/or affect various brain functions. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Drilling Performance of Rock Drill by High-Pressure Water Jet under Different Configuration Modes

    Directory of Open Access Journals (Sweden)

    Songyong Liu

    2017-01-01

    Full Text Available In the rock drilling progress, the resistant force results in tools failure and the low drilling efficiency; thus, it is necessary to reduce the tools failure and enhance the drilling efficiency. In this paper, different configuration modes of drilling performance assisted with water jet are explored based on the mechanism and experiment analysis of rock drilling assisted with water jet. Moreover, the rotary sealing device with high pressure is designed to achieve the axial and rotation movement simultaneously as well as good sealing effect under high-pressure water jet. The results indicate that the NDB and NFB have better effects on drilling performance compared with that of NSB. Moreover, the high-pressure water jet is helpful not only to reduce the drill rod deflection, but also to reduce the probability of drill rod bending and improve the drill rod service life.

  8. EMG activities and plantar pressures during ski jumping take-off on three different sized hills.

    Science.gov (United States)

    Virmavirta, M; Perttunen, J; Komi, P V

    2001-04-01

    Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumpers. The small changes in EMG amplitudes between the hills support the assumption that the take-off was performed with the same intensity on different jumping hills and the timing of the gluteus EMG demonstrates well the similarity of the muscle activation on different hills. On the basis of the results obtained it seems that ski jumping training on small hills does not disturb the movement patterns for bigger hills and can also be helpful for special take-off training with low speed.

  9. Racial differences in the impact of social support on nocturnal blood pressure.

    Science.gov (United States)

    Cooper, Denise C; Ziegler, Michael G; Nelesen, Richard A; Dimsdale, Joel E

    2009-06-01

    To investigate whether black and white adults benefit similarly from perceived social support in relation to blood pressure (BP) dipping during sleep. The Interpersonal Support Evaluation List (ISEL, 12-item version), which measures the perceived availability of several types of functional social support, was examined for interactive effects with race on dipping of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) derived from 24-hour ambulatory blood pressure monitoring (ABPM). The sample consisted of 156 young to middle-aged adults (61 blacks, 95 whites; mean age = 35.7 years). Mean ISEL scores did not differ between racial groups. Controlling for age, body mass index (BMI), resting BP, and socioeconomic status (SES), the interaction of social support by race yielded associations with nighttime dipping in MAP and DBP (p social support increased, white adults received cardiovascular benefits as suggested by enhanced nocturnal dipping of BP, but black adults accrued risks as evidenced by blunted declines in BP during sleep.

  10. Blood pressure reduction induced by low dose of epinephrine via different routes in rats.

    Science.gov (United States)

    Wu, Jing; Ji, Mu-Huo; Wang, Zhong-Yun; Zhu, Wei; Yang, Jian-Jun; Peng, Yong G

    2013-09-01

    Epinephrine was recently shown to induce a hypotension episode. Activation of β₂-adrenoceptors with smooth muscle relaxation may be the underlying mechanism. This study investigated the effects of ICI 118551, a β₂-adrenoceptors antagonist, on epinephrine-induced blood pressure reduction via different administration routes in rats. A total of 144 Sprague Dawley rats were equally randomized into 3 groups (intranasal, intravenous, and intra-arterial administration), each with 4 subgroups: saline + saline, ICI 118551 + saline, saline + epinephrine, and ICI 118551 + epinephrine. All rats were anesthetized while spontaneously breathing. Epinephrine was administered at doses of 5 μg/kg via nose, 0.25 μg/kg via femoral vein, and 0.1 μg/kg via aorta. Mean arterial pressure and heart rate were monitored. Mean arterial pressure decreased in all 3 saline + epinephrine subgroups after administration (P blood pressure reduction can be prevented by ICI 118551 in rats, suggesting that the activation of β₂-adrenoceptors contributes to blood pressure reduction.

  11. Evaluation of Different Dose-Response Models for High Hydrostatic Pressure Inactivation of Microorganisms

    Directory of Open Access Journals (Sweden)

    Sencer Buzrul

    2017-09-01

    Full Text Available Modeling of microbial inactivation by high hydrostatic pressure (HHP requires a plot of the log microbial count or survival ratio versus time data under a constant pressure and temperature. However, at low pressure and temperature values, very long holding times are needed to obtain measurable inactivation. Since the time has a significant effect on the cost of HHP processing it may be reasonable to fix the time at an appropriate value and quantify the inactivation with respect to pressure. Such a plot is called dose-response curve and it may be more beneficial than the traditional inactivation modeling since short holding times with different pressure values can be selected and used for the modeling of HHP inactivation. For this purpose, 49 dose-response curves (with at least 4 log10 reduction and ≥5 data points including the atmospheric pressure value (P = 0.1 MPa, and with holding time ≤10 min for HHP inactivation of microorganisms obtained from published studies were fitted with four different models, namely the Discrete model, Shoulder model, Fermi equation, and Weibull model, and the pressure value needed for 5 log10 (P5 inactivation was calculated for all the models above. The Shoulder model and Fermi equation produced exactly the same parameter and P5 values, while the Discrete model produced similar or sometimes the exact same parameter values as the Fermi equation. The Weibull model produced the worst fit (had the lowest adjusted determination coefficient (R2adj and highest mean square error (MSE values, while the Fermi equation had the best fit (the highest R2adj and lowest MSE values. Parameters of the models and also P5 values of each model can be useful for the further experimental design of HHP processing and also for the comparison of the pressure resistance of different microorganisms. Further experiments can be done to verify the P5 values at given conditions. The procedure given in this study can also be extended for

  12. Predicting mass loading as a function of pressure difference across prefilter/HEPA filter systems

    International Nuclear Information System (INIS)

    Novick, V.J.; Klassen, J.F.; Monson, P.R.

    1992-01-01

    The purpose of this work is to develop a methodology for predicting the mass loading and pressure drop effects on a prefilter/ HEPA filter system. The methodology relies on the use of empirical equations for the specific resistance of the aerosol loaded filter as a function of the particle diameter. These correlations relate the pressure difference across a filter to the mass loading on the filter and accounts for aerosol particle density effects. These predictions are necessary for the efficient design of new filtration systems and for risk assessment studies of existing filter systems. This work specifically addresses the prefilter/HEPA filter Airborne Activity Confinement Systems (AACS) at the Savannah River Plant. In order to determine the mass loading on the system, it is necessary to establish the efficiency characteristics for the prefilter, the mass loading characteristics of the prefilter measured as a function of pressure difference across the prefilter, and the mass loading characteristics of the HEPA filter as a function of pressure difference across the filter. Furthermore, the efficiency and mass loading characteristics need to be determined as a function of the aerosol particle diameter. A review of the literature revealed that no previous work had been performed to characterize the prefilter material of interest. In order to complete the foundation of information necessary to predict total mass loadings on prefilter/HEPA filter systems, it was necessary to determine the prefilter efficiency and mass loading characteristics. The measured prefilter characteristics combined with the previously determined HEPA filter characteristics allowed the resulting pressure difference across both filters to be predicted as a function of total particle mass for a given particle distribution. These predictions compare favorably to experimental measurements (±25%)

  13. Respiratory Pattern and Tidal Volumes Differ for Pressure Support and Volume-assured Pressure Support in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Nicholson, Trevor T; Smith, Sean B; Siddique, Teepu; Sufit, Robert; Ajroud-Driss, Senda; Coleman, John M; Wolfe, Lisa F

    2017-07-01

    Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease resulting in respiratory failure and death. Use of noninvasive ventilation (NIV) improves survival. However, use of volume-assured pressure support (VAPS) has not been extensively studied in ALS. To explore the clinical usefulness of a detailed evaluation of device-recorded NIV data in the management of chronic respiratory failure in ALS, and to determine whether there are differences in efficacy between patients using VAPS or PS. We performed a retrospective chart review of 271 patients with ALS using either PS or VAPS, along with an evaluation of device-recorded data to explore differences in attainment of goal tidal volumes (Vt) and ratio of respiratory rate to tidal volume (f/Vt), in addition to triggering and cycling ability. Two hundred and fifteen patients were using PS, while 56 were using VAPS. There were no significant differences in demographic data, symptoms, pulmonary function, or patient compliance. Compared with VAPS, achieved Vt was significantly lower for PS while f/Vt was significantly higher. Percent spontaneous triggering was relatively preserved in both cohorts, whereas percent spontaneous cycling was considerably decreased in both. Furthermore, there was no association found between spontaneous triggering or cycling, and pulmonary function, indicating the presence of low spontaneous breath cycling or triggering ability is difficult to predict. Examination of device data for exhaled tidal volumes and f/Vt may be of use in evaluating efficacy of NIV in ALS. VAPS provides more reliable goal Vt than does PS, and is associated with decreased f/Vt. Spontaneous cycling is decreased in ALS despite preservation of triggering ability. Although a set backup rate may address decreased triggering, perhaps more importantly, setting a sufficient fixed inspiratory time would address the issue of decreased cycling.

  14. Laser-Induced Graphite Plasma Kinetic Spectroscopy under Different Ambient Pressures

    International Nuclear Information System (INIS)

    Chaudhary, K.; Rosalan, S.; Aziz, M. S.; Bohadoran, M.; Ali, J; Bidin, N.; Saktioto; Yupapin, P. P.

    2015-01-01

    The laser induced plasma dynamics of graphite material are investigated by optical emission spectroscopy. Ablation and excitation of the graphite material is performed by using an 1064nm Nd:YAG laser in different ambient pressures. Characteristics of graphite spectra as line intensity variations and signal-to-noise ratio are presented with a main focus on the influence of the ambient pressure on the interaction of laser-induced graphite plasma with an ambient environment. Atomic emission lines are utilized to investigate the dynamical behavior of plasma, such as the excitation temperature and electron density, to describe emission differences under different ambient conditions. The excitation temperature and plasma electron density are the primary factors which contribute to the differences among the atomic carbon emission at different ambient pressures. Reactions between the plasma species and ambient gas, and the total molecular number are the main factors influencing molecular carbon emission. The influence of laser energy on the plasma interaction with environment is also investigated to demonstrate the dynamical behavior of carbon species so that it can be utilized to optimize plasma fluctuations. (paper)

  15. Pressure distribution under three different types of harnesses used for guide dogs.

    Science.gov (United States)

    Peham, C; Limbeck, S; Galla, K; Bockstahler, B

    2013-12-01

    The aim of this study was to evaluate the pressure distribution under three different types of harnesses used for guide dogs (designated H1, H2 and H3). The dogs (n = 8) led a trainer through a course including a range of exercises (straight line, curve left, curve right, upstairs and downstairs). All dogs were clinically sound and showed no sign of lameness. The pressures beneath the harnesses were determined by sensor strips and related to the gait. In all harnesses, the highest pressures were found in the right sternal region (H1 2.02 ± 0.6N/cm(2); H2 1.76 ± 0.4N/cm(2); H3 1.14 ± 0.5 N/cm(2)). In all other regions, the pressures were in the range of 0-1.32 N/cm(2). The right and left sternal regions were almost constantly loaded. Contrary to previous assumptions, the back regions had minimal loading. This investigation demonstrated that there were significant differences among the harnesses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. [Cholesterolemia and arterial pressure levels. Relationship with different chronic stress configurations].

    Science.gov (United States)

    Bianca de Juárez, M; Iglesias, R; Scoppa, H G; Agnelli, H; Gauna, H F

    2000-01-01

    Several experimental studies refer to the relationship between chronic stress, cholesterolaemia levels and variations in the arterial blood pressure. Our objective is to establish a significant statistical correlation between stress factors, hypertension and hypercholesterolaemia in the studied people. 146 agents were tested among teachers an others employees from the National University of Río Cuarto, who voluntarily went clinical control, reporting data such as arterial pressure, cholesterolaemia, patholgoic records; an standized survey was done considering potentially stress factors, grouped in four different types of stress: (1)-psychoalimentary, (2)-pure psychic, (3)-laboral, (4)-psychofamiliar, giving each of them a value whose addition gane a stress potential factor. The results show that 45.89% of the people studied have hypercholesterolaemia (higher 200 mg% with a mean 237.09 +/- 29.97) being significantly higher (P = 0.001) in the group of employees older than 40 years old., 7.53% of the people showed high arterial pressure, and the 90.90% of this people have hypercholesterolaemia. The hypercholesterolaemic group showed a marked incidence of stress rates higher, with respect to the total people in the four types of stress studied. Significative higher values were observed in the laboral and familiar stress types coinciding with the hypertense group of individuals. According to the collected data we conclude that the relationship between cholesterolaemia, arterial pressure and chronic stress varies with the different types of stress considered, and seem adequate index of stressors levels of studied people.

  17. [Association between two different types of strangling and intraocular pressure variation in jiu-jitsu athletes].

    Science.gov (United States)

    Scarpi, Marinho Jorge; Conte, Marcelo; Rossin, Reginaldo Alexandre; Skubs, Renato; Lenk, Rudolf Eberhard; Brant, Rodrigo

    2009-01-01

    To verify the association between two different types of strangling with intraocular pressure variation in jiu-jitsu athletes. An observational study was performed on 9 athletes of jiu-jitsu, with at least 6 month of training, male, aged 20 to 30 years, without any physical and eyeball lesions. Associations between intraocular pressure and Cross Choke from the guard strangling (E1), and E2 - Cross Choke from mount strangling were gotten. Intraocular pressure was determined by using Perkins tonometer, at first in the absence of physical exercise over the last 24 hours and after each strangling. Then it was carried out the intraocular pressure measure at each 3 minutes, during 12 minutes of exercise recovery (R1, R2, R3, and R4) keeping the athletes lied down. Statistical analysis was done using ANOVA test and Bonferroni post-test. Meaningful reduction of both eyes intraocular pressure occurred at the E2 situation comparing to the E1 situation at all exercise recovery measures: R1 (OD: 8.22 +/- 1.39 vs.11.33 +/- 2.00 / OE: 8.55 +/- 1.23 vs. 11.88 +/- 1.90), R2 (OD: 8.44 +/- 1.87 vs.10.22 +/- 2.53 / OE: 9.00 +/- 1.80 vs. 10.44 +/- 2.35), R3 (OD: 8.44 +/- 1.74 vs.9.78 +/- 2.54 / OE: 8.55 +/- 1.42 vs. 10.33 +/- 1.93) all with pjiu-jitsu strangling exercises, with intraocular pressure reduction.

  18. Dynamic mechanical properties and anisotropy of synthetic shales with different clay minerals under confining pressure

    Science.gov (United States)

    Gong, Fei; Di, Bangrang; Wei, Jianxin; Ding, Pinbo; Shuai, Da

    2018-03-01

    The presence of clay minerals can alter the elastic behaviour of reservoir rocks significantly as the type of clay minerals, their volume and distribution, and their orientation control the shale's intrinsic anisotropic behaviours. Clay minerals are the most abundant materials in shale, and it has been proven extremely difficult to measure the elastic properties of natural shale by means of a single variable (in this case, the type of clay minerals), due to the influences of multiple factors, including water, TOC content and complex mineral compositions. We used quartz, clay (kaolinite, illite and smectite), carbonate and kerogen extract as the primary materials to construct synthetic shale with different clay minerals. Ultrasonic experiments were conducted to investigate the anisotropy of velocity and mechanical properties in dry synthetic and natural shale as a function of confining pressure. Velocities in synthetic shale are sensitive to the type of clay minerals, possibly due to the different structures of the clay minerals. The velocities increase with confining pressure and show higher rate of velocity increase at low pressures, and P-wave velocity is usually more sensitive than S-wave velocity to confining pressure according to our results. Similarly, the dynamic Young's modulus and Poisson's ratio increase with applied pressure, and the results also reveal that E11 is always larger than E33 and ν31 is smaller than ν12. Velocity and mechanical anisotropy decrease with increasing stress, and are sensitive to stress and the type of clay minerals. However, the changes of mechanical anisotropy with applied stress are larger compared with the velocity anisotropy, indicating that mechanical properties are more sensitive to the change of rock properties.

  19. Sex differences in step count-blood pressure association: a preliminary study in type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Priya Manjoo

    Full Text Available BACKGROUND: Walking and cardiovascular mortality are inversely associated in type 2 diabetes, but few studies have objectively measured associations of walking with individual cardiovascular risk factors. Such information would be useful for "dosing" daily steps in clinical practice. This study aimed to quantify decrements in blood pressure and glycated hemoglobin (A1C per 1,000 daily step increments. METHODOLOGY/PRINCIPAL FINDINGS: Two hundred and one subjects with type 2 diabetes underwent assessments of step counts (pedometer-measured, blood pressure, A1C and anthropometric parameters. Due to missing data, the final analysis was conducted on 83 women and 102 men, with a mean age of 60 years. Associations of daily steps with blood pressure and A1C were evaluated using sex-specific multivariate linear regression models (adjusted for age, ethnicity, and BMI. Potential sex differences were confirmed in a combined model (women and men with interaction terms. Mean values for daily steps, blood pressure, A1C and BMI were 5,357 steps/day; 137/80 mm Hg; 7.7% and 30.4 kg/m(2 respectively. A 1,000 daily step increment among women was associated with a -2.6 (95% CI: -4.1 to -1.1 mm Hg change in systolic and a -1.4 (95% CI: -2.2 to -0.6 mm Hg change in diastolic blood pressure. Among men, corresponding changes were -0.7 (95% CI: -2.1 to 0.7 and -0.6 (95% CI: -1.4 to 0.3 mm Hg, respectively. Sex differences were confirmed in combined models. Step counts and A1C did not demonstrate clinically important associations. CONCLUSIONS/SIGNIFICANCE: A 1,000 steps/day increment is associated with important blood pressure decrements among women with type 2 diabetes but the data were inconclusive among men. Targeted "dose increments" of 1,000 steps/day in women may lead to measurable blood pressure reductions. This information may be of potential use in the titration or "dosing" of daily steps. No associations were found between step count increments and A1C.

  20. Hypovolemic men and women regulate blood pressure differently following exposure to artificial gravity.

    Science.gov (United States)

    Evans, Joyce M; Ribeiro, L Christine; Moore, Fritz B; Wang, Siqi; Zhang, Qingguang; Kostas, Vladimir; Ferguson, Connor R; Serrador, Jorge; Falvo, Michael; Stenger, Michael B; Goswami, Nandu; Rask, Jon C; Smith, Jeffrey D; Knapp, Charles F

    2015-12-01

    In addition to serious bone, vestibular, and muscle deterioration, space flight leads to cardiovascular dysfunction upon return to gravity. In seeking a countermeasure to space flight-induced orthostatic intolerance, we previously determined that exposure to artificial gravity (AG) training in a centrifuge improved orthostatic tolerance of ambulatory subjects. This protocol was more effective in men than women and more effective when subjects exercised. We now determine the orthostatic tolerance limit (OTL) of cardiovascularly deconditioned (furosemide) men and women on one day following 90 min of AG compared to a control day (90 min of head-down bed rest, HDBR). There were three major findings: a short bout of artificial gravity improved orthostatic tolerance of hypovolemic men (30 %) and women (22 %). Men and women demonstrated different mechanisms of cardiovascular regulation on AG and HDBR days; women maintained systolic blood pressure the same after HDBR and AG exposure while men's systolic pressure dropped (11 ± 2.9 mmHg) after AG. Third, as presyncopal symptoms developed, men's and women's cardiac output and stroke volume dropped to the same level on both days, even though the OTL test lasted significantly longer on the AG day, indicating cardiac filling as a likely variable to trigger presyncope. (1) Even with gender differences, AG should be considered as a space flight countermeasure to be applied to astronauts before reentry into gravity, (2) men and women regulate blood pressure during an orthostatic stress differently following exposure to artificial gravity and (3) the trigger for presyncope may be cardiac filling.

  1. Effect of different pneumoperitoneum pressure on stress state in patients underwent gynecological laparoscopy

    Directory of Open Access Journals (Sweden)

    Ai-Yun Shen

    2016-10-01

    Full Text Available Objective: To observe the effect of different CO2 pneumoperitoneum pressure on the stress state in patients underwent gynecological laparoscopy. Methods: A total of 90 patients who were admitted in our hospital from February, 2015 to October, 2015 for gynecological laparoscopy were included in the study and divided into groups A, B, and C according to different CO2 pneumoperitoneum pressure. The changes of HR, BP, and PetCO2 during the operation process in the three groups were recorded. The changes of stress indicators before operation (T0, 30 min during operation (T1, and 12 h after operation (T2 were compared. Results: The difference of HR, BP, and PetCO2 levels before operation among the three groups was not statistically significant (P>0.05. HR, BP, and PetCO2 levels 30 min after pneumoperitoneum were significantly elevated when compared with before operation (P0.05. PetCO2 level 30 min after pneumoperitoneum in group B was significantly higher than that in group A (P0.05. Conclusions: Low pneumoperitoneum pressure has a small effect on the stress state in patients underwent gynecological laparoscopy, will not affect the surgical operation, and can obtain a preferable muscular relaxation and vision field; therefore, it can be selected in preference.

  2. A discussion of hyperbolicity in CATHENA 4. Virtual mass and phase-to-interface pressure differences

    International Nuclear Information System (INIS)

    Aydemir, Nusret U.

    2012-01-01

    It is well known that the one-dimensional equations of motion for two-phase flow are non-hyperbolic. Non-hyperbolicity can lead to numerical instabilities, destroying the solution. However, researchers in the last few decades were able to show that inclusion of virtual mass and/or phase-to-interface pressure differences in the momentum equations successfully render the equations of motion hyperbolic. In the present paper, the effect of including virtual mass and phase-to-interface pressure terms in the momentum equations on the hyperbolicity of the two-phase model in the CATHENA 4 code is discussed. The study is motivated by the fact that the inclusion of either model has been shown in the open literature to lead to a hyperbolic system separately. However, no known study exists that examine hyperbolicity in the presence of both these terms in the momentum equations. In this work, both terms are considered in the model equations simultaneously and their implications on the hyperbolicity of the two-phase model are discussed. Specifically, it is shown that in the case of mixed flow, there is a distinct region of non-hyperbolicity that developers need to be aware of when their equations include both the virtual mass and the phase-to-interface terms. Selecting the coefficients of phase-to-interface pressure difference terms properly ensures that the equations are hyperbolic for a wide range of conditions. (orig.)

  3. Mean Blood Pressure Assessment during Post-Exercise: Result from Two Different Methods of Calculation

    Directory of Open Access Journals (Sweden)

    Gianmarco Sainas, Raffaele Milia, Girolamo Palazzolo, Gianfranco Ibba, Elisabetta Marongiu, Silvana Roberto, Virginia Pinna, Giovanna Ghiani, Filippo Tocco, Antonio Crisafulli

    2016-09-01

    Full Text Available At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP is usually calculated with a standard formula (SF as follows: MBP = diastolic blood pressure (DBP + 1/3 [systolic blood pressure (SBP – DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by –4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg. Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation.

  4. Clam bioaccumulation of Alkylphenols and Polyciclic aromatic hydrocarbons in the Venice lagoon under different pressures.

    Science.gov (United States)

    Ademollo, N; Patrolecco, L; Matozzo, V; Marin, M G; Valsecchi, S; Polesello, S

    2017-11-15

    Biota-Sediment Accumulation Factors (BSAFs) of nonylphenols (NPs) and polycyclic aromatic hydrocarbons (PAHs) in Ruditapes philippinarum from the Venice Lagoon (Italy) were determined with the aim to verify whether the routine biomonitoring studies are reliable in contaminated sites. Clams and sediments were collected in field campaigns (October 2003 to June 2004) in three sites of the Venice Lagoon. Results showed that Marghera and Campalto sediments were more contaminated by NPs and PAHs than Poveglia. Different trends were observed in the contamination of clams with the highest BSAFs found at Poveglia. BSAF trend appeared to be inversely related to the contaminant pressure on the sites. These results suggest that clam bioaccumulation is not always representative of the chemical pressure on aquatic biota. The direct correlation between sediment and biota concentrations in contaminated sites can be lost as a function of the site-specific conditions such as sediment toxicity and food availability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Positron Annihilation and Complementary Studies of Copper Sandblasted with Alumina Particles at Different Pressures

    Directory of Open Access Journals (Sweden)

    Paweł Horodek

    2017-11-01

    Full Text Available Positron annihilation spectroscopy and complementary methods were used to detect changes induced by sandblasting of alumina particles at different pressures varying from 1 to 6 bar in pure well-annealed copper. The positron lifetime measurements revealed existence of dislocations and vacancy clusters in the adjoined surface layer. The presence of retained alumina particles in the copper at the depth below 50 µm was found in the SEM pictures and also in the annihilation line shape parameter profiles measured in the etching experiment. The profiles show us that the total depth of damaged zones induced by sandblasting of alumina particles ranges from 140 µm up to ca. 800 µm and it depends on the applied pressure. The work-hardening of the adjoined surface layer was found in the microhardness measurements at the cross-section of the sandblasted samples.

  6. Positron Annihilation and Complementary Studies of Copper Sandblasted with Alumina Particles at Different Pressures.

    Science.gov (United States)

    Horodek, Paweł; Siemek, Krzysztof; Dryzek, Jerzy; Wróbel, Mirosław

    2017-11-23

    Positron annihilation spectroscopy and complementary methods were used to detect changes induced by sandblasting of alumina particles at different pressures varying from 1 to 6 bar in pure well-annealed copper. The positron lifetime measurements revealed existence of dislocations and vacancy clusters in the adjoined surface layer. The presence of retained alumina particles in the copper at the depth below 50 µm was found in the SEM pictures and also in the annihilation line shape parameter profiles measured in the etching experiment. The profiles show us that the total depth of damaged zones induced by sandblasting of alumina particles ranges from 140 µm up to ca. 800 µm and it depends on the applied pressure. The work-hardening of the adjoined surface layer was found in the microhardness measurements at the cross-section of the sandblasted samples.

  7. Effects of tractor loads and tyre pressures on soil compaction in Tunisia under different moisture conditions

    Science.gov (United States)

    Khemis, Chiheb; Abrougui, Khaoula; Ren, Lidong; Mutuku, Eunice Ann; Chehaibi, Sayed; Cornelis, Wim

    2017-04-01

    Vegetables in Tunisia demand frequent tractor traffic for soil tillage, cultural operations and phytosanitary treatment, resulting in soil compaction. This study evaluates the effects of four levels of compaction by using different loads and tyre pressures of tractors, i.e., load 1 (C1) = 1460 kg, load 2 (C2) = 3100 kg, tyre pressure 1 (C3) = 800 kg cm-2, tyre pressure 2 (C4) = 1500 kg cm-2 on the hydraulic and physical properties of a sandy loam (10% clay, 20% silt, 68% sand) under three natural moisture conditions H0, H1 (15 days later), H2 (30 days later). At H0 average water content between 0 and 30 cm depth varied from 0.04 to 0.06 kg kg-1, at H1 between 0.13 and 0.07 kg kg-1, and at H2 between 0.10 and 0.09 kg kg-1. Each test run was limited to one pass. Undisturbed soil cores were collected in the topsoil (0-10 cm), at 10-20 cm and in the subsoil (20-30 cm) below the trace of the wheel at sites in the Higher Institute of Agronomy of Chott Mariam, Sousse, Tunisia. Soil compaction level was determined by penetration resistance using a penetrologger. Porosity, bulk density and permeability were then determined to evaluate the impact of the four load/tyre pressure combinations at the three moisture conditions on soil compaction. Prior to the experiment (C0), bulk density was 1.4 Mg m-3. After the tractor pass, the highest degree of compaction was observed with tractor load C2 and tyre pressure C4 which significantly changed soil bulk density resulting in values of up to 1.71 Mg m-3 in the topsoil and compacted subsoil under H2, which is significantly above the critical value of 1.6 Mg m-3 for soils with clay content below 17.5%. The high degree of compaction significantly affected penetration resistance and porosity of both topsoil and subsoil layers accordingly. Permeability was significantly reduced as a result of the induced compaction. The results demonstrate that different degrees of soil compaction under different moisture levels could greatly influence

  8. Assessment of plantar pressure in forefoot relief shoes of different designs.

    Science.gov (United States)

    Carl, Hans-Dieter; Pfander, David; Swoboda, Bernd

    2006-02-01

    After reconstructive forefoot surgery, patients require complete or partial forefoot relief, which can be obtained with a variety of shoe designs. The aim of this study was to evaluate the effectiveness of two different types of forefoot-relief shoes frequently used after surgery, especially their safety against unintentional forefoot load. Ten healthy volunteers were asked to perform five trials on a treadmill at self-selected speeds. In the first trial, mean peak pressure values in mass-produced shoes and insoles were evaluated and considered as 100%. Two different shoe designs (short heel-short sole, ii: short heel-complete sole) were compared in two trials each with appropriate and inappropriate use (attempting to put weight on the forefoot) gait pattern. Plantar pressure values were obtained using the Pedar cable system (Novel Inc., Munich, Germany). For analysis, pedobarographic pictures were subdivided into midfoot (31% to 60% of the total insole length) and forefoot (61% to 100% of the total insole length). ANOVA was used for statistical analysis, and p values less than 0.01 were considered significant. With the short-soled shoe, forefoot and midfoot relief was 100% in both compliant and in noncompliant use. With wearing a complete sole, compliant use led to a significant reduction (p shoe produced mean peak pressure values significantly higher (p shoes under the forefoot, but not under the midfoot. Forefoot-relief shoes are effective in reducing both mean and peak plantar pressures. Shoes with a nonsupported midfoot and forefoot may be safer with inappropriate use than shoes with a complete sole. The kind of forefoot shoe should be carefully chosen to regulate weightbearing after reconstructive forefoot surgery.

  9. Analysis for pressure transient of coalbed methane reservoir based on Laplace transform finite difference method

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2015-09-01

    Full Text Available Based on fractal geometry, fractal medium of coalbed methane mathematical model is established by Langmuir isotherm adsorption formula, Fick's diffusion law, Laplace transform formula, considering the well bore storage effect and skin effect. The Laplace transform finite difference method is used to solve the mathematical model. With Stehfest numerical inversion, the distribution of dimensionless well bore flowing pressure and its derivative was obtained in real space. According to compare with the results from the analytical method, the result from Laplace transform finite difference method turns out to be accurate. The influence factors are analyzed, including fractal dimension, fractal index, skin factor, well bore storage coefficient, energy storage ratio, interporosity flow coefficient and the adsorption factor. The calculating error of Laplace transform difference method is small. Laplace transform difference method has advantages in well-test application since any moment simulation does not rely on other moment results and space grid.

  10. Emergence of ethnic differences in blood pressure in adolescence: the determinants of adolescent social well-being and health study.

    Science.gov (United States)

    Harding, Seeromanie; Whitrow, Melissa; Lenguerrand, Erik; Maynard, Maria; Teyhan, Alison; Cruickshank, J Kennedy; Der, Geoff

    2010-04-01

    The cause of ethnic differences in cardiovascular disease remains a scientific challenge. Blood pressure tracks from late childhood to adulthood. We examined ethnic differences in changes in blood pressure between early and late adolescence in the United Kingdom. Longitudinal measures of blood pressure, height, weight, leg length, smoking, and socioeconomic circumstances were obtained from London, United Kingdom, schoolchildren of White British (n=692), Black Caribbean (n=670), Black African (n=772), Indian (n=384), and Pakistani and Bangladeshi (n=402) ethnicity at 11 to 13 years and 14 to 16 years. Predicted age- and ethnic-specific means of blood pressure, adjusted for anthropometry and social exposures, were derived using mixed models. Among boys, systolic blood pressure did not differ by ethnicity at 12 years, but the greater increase among Black Africans than Whites led to higher systolic blood pressure at 16 years (+2.9 mm Hg). Among girls, ethnic differences in mean systolic blood pressure were not significant at any age, but while systolic blood pressure hardly changed with age among White girls, it increased among Black Caribbeans and Black Africans. Ethnic differences in diastolic blood pressure were more marked than those for systolic blood pressure. Body mass index, height, and leg length were independent predictors of blood pressure, with few ethnic-specific effects. Socioeconomic disadvantage had a disproportionate effect on blood pressure for girls in minority groups. The findings suggest that ethnic divergences in blood pressure begin in adolescence and are particularly striking for boys. They signal the need for early prevention of adverse cardiovascular disease risks in later life.

  11. Golf styles and centre of pressure patterns when using different golf clubs.

    Science.gov (United States)

    Ball, Kevin A; Best, Russell

    2011-03-01

    When using a driver, the centre of pressure of a golfer shows a pattern that is characteristic of one of two distinct swing styles: the "front foot" style or the "reverse" style. The aim of this study was to establish whether these two swing styles are also evident when using other clubs, and if so, to determine whether golfers use the same swing style when using different clubs. Forty-six professional, amateur, and recreational golfers performed swings to hit a ball into a net placed 3 m away. Ten swings were performed for each of the driver, 3-iron, and 7-iron while standing on two force plates. The position of the golfer's centre of pressure parallel with the line of shot and relative to the feet was quantified at eight swing events that were identified from 200-Hz video. Cluster analysis confirmed that the front foot and reverse styles were evident in all three clubs, and most of the golfers (96%) used the same swing style for all three clubs. Golfers that used the reverse swing positioned their centre of pressure nearer to their toes at ball contact compared with golfers that used the front foot swing.

  12. Effect of CO2 partial pressure and different CO2 phases on carbon steel corrosion

    Science.gov (United States)

    Mahlobo, MGR; Premlall, K.; Olubambi, PA

    2017-12-01

    Carbon capture and storage (CCS) is the recent promising technology aimed at reducing greenhouse gas emission. Like many other developed technologies, CCS is faced with great challenges such as pipeline transportation failure due to corrosion. There are many factors contributing to steel corrosion during the pipeline transportation of carbon dioxide (CO2). This study focuses on CO2 partial pressure and different phases of CO2 as some of the factors contributing to steel corrosion. Carbon steel was used as a testing specimen. High pressure reactor was used in this study to compress CO2 from low to high pressures ultimately changing the CO2 from gaseous phase to gas/liquid phase (subcritical) and to dense phase (supercritical). Weight loss method was employed to determine the corrosion rate while scanning electron microscopy (SEM) and X-Ray diffraction (XRD) were used to study the carbon steel morphology and phase analysis. Using low magnification digital camera, the type of corrosion that took place on the carbon steel surface was identified.

  13. Burst pressure of phaseguide structures of different heights in all-polymer microfluidic channels

    Science.gov (United States)

    Garbarino, Francesca; Kistrup, Kasper; Rizzi, Giovanni; Fougt Hansen, Mikkel

    2017-12-01

    We present an experimental investigation of the burst/overflow pressure of water and a representative surfactant-containing buffer in microfluidic channels with phaseguide structures oriented at an angle of 90° to the channel length as a function of their height, h . The all-polymer chips were fabricated by injection moulding and sealed by ultrasonic welding. Channels with a height of 200 μ m and widths of 1 mm or 3 mm were investigated for five values of h between 8 μ m and 82 μ m. Phaseguide structures without branches and with branches at angles α   =  45°, 60° and 75° were studied. All phaseguide structures were found able to pin both liquids and the burst pressure was found to increase approximately linearly with the height of the phaseguide from about 100-350 Pa for water and from about 25-200 Pa for the buffer. The burst pressure was found not to depend on the channel width and it was only weakly influenced by the presence of a branch on the phaseguide. For phaseguides with a branch, the liquid was always found to burst at the branch location. The measured burst pressures were compared to those estimated using a simple theory. The knowledge obtained in this study enables simple tuning of liquid spreading and overflow in microfluidic channels by use of phaseguide structures with different heights and it also provides a set of systematic experimental data to be compared with simulations/theory.

  14. Comparative study on two different seal surface structure for reactor pressure vessel sealing behavior

    International Nuclear Information System (INIS)

    Chen Jun; Xiong Guangming; Deng Xiaoyun

    2014-01-01

    The seal surface structure is very important to reactor pressure vessel (RPV) sealing behavior. In this paper, two 3-D RPV sealing analysis finite models have been established with different seal surface structures, in order to study the influence of two structures. The separation of RPV upper and lower flanges, bolt loads and etc. are obtained, which are used to evaluate the sealing behavior of the RPV. Meanwhile, the comparative analysis of safety margin of two seal surface structural had been done, which provides the theoretical basis for RPV seal structure design optimization. (authors)

  15. Age-specific differences between conventional and ambulatory daytime blood pressure values

    DEFF Research Database (Denmark)

    Conen, David; Aeschbacher, Stefanie; Thijs, Lutgarde

    2014-01-01

    Mean daytime ambulatory blood pressure (BP) values are considered to be lower than conventional BP values, but data on this relation among younger individuals ... population-based cohorts. We compared individual differences between daytime ambulatory and conventional BP according to 10-year age categories. Age-specific prevalences of white coat and masked hypertension were calculated. Among individuals aged 18 to 30, 30 to 40, and 40 to 50 years, mean daytime BP.......2 mm Hg for diastolic BP; all PMasked hypertension was more prevalent among men...

  16. High hydrostatic pressure resistance of Campylobacter jejuni after different sublethal stresses.

    Science.gov (United States)

    Sagarzazu, N; Cebrián, G; Condón, S; Mackey, B; Mañas, P

    2010-07-01

    To study the development of resistance responses in Campylobacter jejuni to high hydrostatic pressure (HHP) treatments after the exposure to different stressful conditions that may be encountered in food-processing environments, such as acid pH, elevated temperatures and cold storage. Campylobacter jejuni cells in exponential and stationary growth phase were exposed to different sublethal stresses (acid, heat and cold shocks) prior to evaluate the development of resistance responses to HHP. For exponential-phase cells, neither of the conditions tested increased nor decreased HHP resistance of C. jejuni. For stationary-phase cells, acid and heat adaptation-sensitized C. jejuni cells to the subsequent pressure treatment. On the contrary, cold-adapted stationary-phase cells developed resistance to HHP. Whereas C. jejuni can be classified as a stress sensitive micro-organism, our findings have demonstrated that it can develop resistance responses under different stressing conditions. The resistance of stationary phase C. jejuni to HHP was increased after cells were exposed to cold temperatures. The results of this study contribute to a better knowledge of the physiology of C. jejuni and its survival to food preservation agents. Results here presented may help in the design of combined processes for food preservation based on HHP technology. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.

  17. Parameters of the center of pressure displacement on the saddle during hippotherapy on different surfaces

    Directory of Open Access Journals (Sweden)

    Fabiana M. Flores

    2015-06-01

    Full Text Available Background: Hippotherapy uses horseback riding movements for therapeutic purposes. In addition to the horse's movement, the choice of equipment and types of floor are also useful in the intervention. The quantification of dynamic parameters that define the interaction of the surface of contact between horse and rider provides insight into how the type of floor surface variations act upon the subject's postural control. Objective: To test whether different types of surfaces promote changes in the amplitude (ACOP and velocity (VCOP of the center of pressure (COP displacement during the rider's contact with the saddle on the horse's back. Method: Twenty two healthy adult male subjects with experience in riding were evaluated. The penetration resistances of asphalt, sand and grass surfaces were measured. The COP data were collected on the three surfaces using a pressure measurement mat. Results: ACOP values were higher in sand, followed by grass and asphalt, with significant differences between sand and asphalt (anteroposterior, p=0.042; mediolateral, p=0.019. The ACOP and VCOP values were higher in the anteroposterior than in the mediolateral direction on all surfaces (ACOP, p=0.001; VCOP, p=0.006. The VCOP did not differ between the surfaces. Conclusion: Postural control, measured by the COP displacement, undergoes variations in its amplitude as a result of the type of floor surface. Therefore, these results reinforce the importance of the choice of floor surface when defining the strategy to be used during hippotherapy intervention.

  18. Parameters of the center of pressure displacement on the saddle during hippotherapy on different surfaces.

    Science.gov (United States)

    Flores, Fabiana M; Dagnese, Frederico; Mota, Carlos B; Copetti, Fernando

    2015-01-01

    Hippotherapy uses horseback riding movements for therapeutic purposes. In addition to the horse's movement, the choice of equipment and types of floor are also useful in the intervention. The quantification of dynamic parameters that define the interaction of the surface of contact between horse and rider provides insight into how the type of floor surface variations act upon the subject's postural control. To test whether different types of surfaces promote changes in the amplitude (ACOP) and velocity (VCOP) of the center of pressure (COP) displacement during the rider's contact with the saddle on the horse's back. Twenty two healthy adult male subjects with experience in riding were evaluated. The penetration resistances of asphalt, sand and grass surfaces were measured. The COP data were collected on the three surfaces using a pressure measurement mat. ACOP values were higher in sand, followed by grass and asphalt, with significant differences between sand and asphalt (anteroposterior, p=0.042; mediolateral, p=0.019). The ACOP and VCOP values were higher in the anteroposterior than in the mediolateral direction on all surfaces (ACOP, p=0.001; VCOP, p=0.006). The VCOP did not differ between the surfaces. Postural control, measured by the COP displacement, undergoes variations in its amplitude as a result of the type of floor surface. Therefore, these results reinforce the importance of the choice of floor surface when defining the strategy to be used during hippotherapy intervention.

  19. Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices

    OpenAIRE

    Monnet, Xavier; Anguel, Nadia; Naudin, Brice; Jabot, Julien; Richard, Christian; Teboul, Jean-Louis

    2010-01-01

    Introduction We compared the ability of two devices estimating cardiac output from arterial pressure-curve analysis to track the changes in cardiac output measured with transpulmonary thermodilution induced by volume expansion and norepinephrine in sepsis patients. Methods In 80 patients with septic circulatory failure, we administered volume expansion (40 patients) or introduced/increased norepinephrine (40 patients). We measured the pulse contour-derived cardiac index (CI) provided by the P...

  20. Interarm differences in systolic blood pressure and mortality among US army veterans

    DEFF Research Database (Denmark)

    White, James; Mortensen, Laust Hvas; Kivimäki, Mika

    2014-01-01

    BACKGROUND: Differences between the arms in systolic blood pressure (SBP) of ≥10 mmHg have been associated with an increased risk of mortality in patients with hypertensive and chronic renal disease. For the first time, we examined these relationships in a non-clinical population. DESIGN: Cohort...... study. METHODS: Participants were 4419 men (mean age 38.37 years) from the Vietnam Experience Study. Bilateral SBP and diastolic BP (DBP), serum lipids, fasting glucose, erythrocyte sedimentation rate, metabolic syndrome, and ankle brachial index were assessed in 1986. RESULTS: Ten per cent of men had....... CONCLUSIONS: In this non-clinical cohort study, interarm differences in SBP were not associated with mortality after accounting for traditional CVD risk factors. Interarm differences might not be valuable as an additional risk factor for mortality in populations with a low risk of CVD....

  1. Climate and Human Pressure Constraints Co-Explain Regional Plant Invasion at Different Spatial Scales.

    Science.gov (United States)

    Campos, Juan Antonio; García-Baquero, Gonzalo; Caño, Lidia; Biurrun, Idoia; García-Mijangos, Itziar; Loidi, Javier; Herrera, Mercedes

    2016-01-01

    Alien species invasion represents a global threat to biodiversity and ecosystems. Explaining invasion patterns in terms of environmental constraints will help us to assess invasion risks and plan control strategies. We aim to identify plant invasion patterns in the Basque Country (Spain), and to determine the effects of climate and human pressure on that pattern. We modeled the regional distribution of 89 invasive plant species using two approaches. First, distance-based Moran's eigenvector maps were used to partition variation in the invasive species richness, S, into spatial components at broad and fine scales; redundancy analysis was then used to explain those components on the basis of climate and human pressure descriptors. Second, we used generalized additive mixed modeling to fit species-specific responses to the same descriptors. Climate and human pressure descriptors have different effects on S at different spatial scales. Broad-scale spatially structured temperature and precipitation, and fine-scale spatially structured human population density and percentage of natural and semi-natural areas, explained altogether 38.7% of the total variance. The distribution of 84% of the individually tested species was related to either temperature, precipitation or both, and 68% was related to either population density or natural and semi-natural areas, displaying similar responses. The spatial pattern of the invasive species richness is strongly environmentally forced, mainly by climate factors. Since individual species responses were proved to be both similarly constrained in shape and explained variance by the same environmental factors, we conclude that the pattern of invasive species richness results from individual species' environmental preferences.

  2. Foot-type analysis and plantar pressure differences between obese and nonobese adolescents during upright standing.

    Science.gov (United States)

    Cimolin, Veronica; Capodaglio, Paolo; Cau, Nicola; Galli, Manuela; Pau, Massimiliano; Patrizi, Alessandra; Tringali, Gabriella; Sartorio, Alessandro

    2016-03-01

    This study aimed to characterize the effect of obesity on foot-type and plantar pressure distribution in adolescents. Ten obese adolescents (obese group; BMI: 35.45±4.73 kg/m) and eight normal-weighted adolescents (control group; BMI: 18.67±2.46 kg/m) were recruited. Both groups were evaluated while standing using the Pedar-X in-shoe system. Foot-ground contact was characterized using contact area, peak of force and pressure calculated for the subareas of the foot. The analysis showed that obese participants had significantly higher area of contact in forefoot and midfoot (only in medial area) regions in comparison with the control group, whereas no statistically significant differences were observed for the rearfoot region. As far as the maximum pressure and force was concerned, similar results were obtained for both groups. Obese participants showed higher values for all the regions, with the exception of medial rearfoot area, for which the values were similar between the two groups. The analysis of foot-type distribution displayed that in the obese group high percentage of participants presented flat foot (70%) respect to cavus foot (20%) and normal foot (10%); on the contrary, in the control group, foot-types were markedly different, with 25% of participants with flat foot, 25% with cavus foot and 50% with normal foot. These results are important from a clinical perspective to develop and enhance the rehabilitative options in these patients and to avoid a worsening of their foot abnormalities. Untreated flat foot can in fact be disabling and over time can result in significant difficulties for the patient.

  3. Dynamic response of liquid-filled catheter systems for measurement of blood pressure: precision of measurements and reliability of the Pressure Recording Analytical Method with different disposable systems.

    Science.gov (United States)

    Romagnoli, Stefano; Romano, Salvatore Mario; Bevilacqua, Sergio; Lazzeri, Chiara; Gensini, Gian Franco; Pratesi, Carlo; Quattrone, Diego; Dini, Daniele; De Gaudio, Angelo Raffaele

    2011-08-01

    We aimed to compare the effects of a blood pressure transducer system specifically manufactured to limit underdamping artifacts with those of a standard system on hemodynamic parameter estimation and accuracy. Forty-three consecutive patients undergoing vascular surgery at the University of Florence, Italy, were included. Arterial blood pressure signal was simultaneously registered with 2 MostCare monitors, connected to the artery either by a standard transducer or a specific transducer manufactured to avoid underdamping artifacts (Resonance Over-Shoot Eliminator [R.O.S.E.]; Becton Dickinson, Becton Drive, NJ). Patients were divided into 2 groups: absence (C group) or presence (R group) of underdamping/resonance artifacts of blood pressure signal. Systolic blood pressure, cardiac index, maximal pressure/time ratio (dP/dt(MAX)), and cardiac cycle efficiency were recorded every 30 seconds for 30 minutes. A total of 2675 measurements were performed with 34.9% incidence of underdamping/resonance artifacts. All hemodynamic parameters showed clinically acceptable differences in the C group; in contrast, the results differed greatly in the R group between standard and R.O.S.E. transducer (systolic blood pressure bias, 16.7 mm Hg; cardiac index bias, 0.24 L min(-1) m(-2); dP/dt(MAX) bias, 0.92 mm Hg/ms; cardiac cycle efficiency bias, 0.018 units). Underdamping/resonance artifacts frequently affect blood pressure measurement in operating rooms and intensive care units and cause severe overestimation of systolic blood pressure and incorrect estimation of hemodynamic parameters when the pulse contour method is used. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Thermodynamics of the multicomponent vapor-liquid equilibrium under capillary pressure difference

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    2001-01-01

    We discuss the two-phase multicomponent equilibrium, provided that the phase pressures are different due to the action of capillary forces. We prove the two general properties of such an equilibrium, which have previously been known for a single-component case, however, to the best of our knowledge......, not for the multicomponent mixtures. The importance is emphasized on the space of the intensive variables P, T and mu (i), where the laws of capillary equilibrium have a simple geometrical interpretation. We formulate thermodynamic problems specific to such an equilibrium, and outline changes to be introduced to common...... algorithms of flash calculations in order to solve these problems. Sample calculations show large variation of the capillary properties of the mixture in the very neighborhood of the phase envelope and the restrictive role of the spinodal surface as a boundary for possible equilibrium states with different...

  5. Assessing intravascular volume by difference in pulse pressure in pigs submitted to graded hemorrhage.

    Science.gov (United States)

    Pestel, Gunther J; Hiltebrand, Luzius B; Fukui, Kimiko; Cohen, Delphine; Hager, Helmut; Kurz, Andrea M

    2006-10-01

    We assessed changes in intravascular volume monitored by difference in pulse pressure (dPP%) after stepwise hemorrhage in an experimental pig model. Six pigs (23-25 kg) were anesthetized (isoflurane 1.5 vol%) and mechanically ventilated to keep end-tidal CO2 (etCO2) at 35 mmHg. A PA-catheter and an arterial catheter were placed via femoral access. During and after surgery, animals received lactated Ringer's solution as long as they were considered volume responders (dPP>13%). Then animals were allowed to stabilize from the induction of anesthesia and insertion of catheters for 30 min. After stabilization, baseline measurements were taken. Five percent of blood volume was withdrawn, followed by another 5%, and then in 10%-increments until death from exsanguination occurred. After withdrawal of 5% of blood volume, all pigs were considered volume responders (dPP>13%); dPP rose significantly from 6.1+/-3.3% to 19.4+/-4.2%. The regression analysis of stepwise hemorrhage revealed a linear relation between blood loss (hemorrhage in %) and dPP (y=0.99*x+14; R2=0.7764; P<.0001). In addition, dPP was the only parameter that changed significantly between baseline and a blood loss of 5% (P<0.01), whereas cardiac output, stroke volume, heart rate, MAP, central venous pressure, pulmonary artery occlusion pressure, and systemic vascular resistance, respectively, remained unchanged. We conclude that in an experimental hypovolemic pig model, dPP correlates well with blood loss.

  6. Effects of salt substitute on home blood pressure differs according to age and degree of blood pressure in hypertensive patients and their families.

    Science.gov (United States)

    Hu, Jihong; Zhao, Liancheng; Thompson, Brian; Zhang, Yawei; Wu, Yangfeng

    2018-02-05

    It is known that home blood pressure (HBP) is a more reliable assessment of hypertension treatments than clinical blood pressure (BP). Despite this, HBP response to a salt substitute has only been evaluated by one study which, did not look at the salt substitute's effect on family members and did not analyze by age, gender, or BP degree. The aim of this current study was to assess the effects of a low-sodium and high-potassium salt substitute on HBP among hypertensive patients and their family members. A total of 220 households (including 220 hypertensive patients and 380 their families) were randomly assigned to the regular salt or salt substitute groups. HBP was measured at the beginning, 3rd, 6th, and 12th months. Among the patients (n = 220), only home systolic blood pressure (HSBP) was significantly reduced, by an adjusted baseline BP of 4.2 mm Hg (95% CI: 1.3-7.0 mm Hg), in the salt substitute group compared with those in the regular salt group at each visit (all P blood pressure (HDBP) at any visit. Among the family members, HSBP and HDBP were not significantly different between the groups. Furthermore, Individuals ≥60 years old, hypertensive patients with stage-2 hypertension, family members with hypertension, and women experienced greater HSBP reduction. Older subjects, those with higher blood pressure, and women experienced greater home blood pressure reduction from the salt substitute compared to regular salt.

  7. Displacement of an electric arc by a stationary transverse magnetic field to different pressures of the ionized gas

    International Nuclear Information System (INIS)

    Ramos, J.

    1987-01-01

    The displacement of a wall-stabilized electric arc by a stationary transverse magnetic field is measured to different pressures of the ionized gas. The increase of the pressure makes the heat transfer function and the mass flow velocity in the arc column to raise, and it makes the arc displacement to decrease. (author)

  8. Numerical study of pressure fluctuations in different guide vanes' opening angle in pump mode of a pump turbine

    International Nuclear Information System (INIS)

    Sun, Y K; Zuo, Z G; Liu, S H; Wu, Y L; Liu, J T

    2012-01-01

    A numerical model based on a pumped storage power station was built to develop the numerical simulation, to analyze the pressure fluctuations in a pump turbine in different guide vanes' opening angle. The different guide vanes' opening angles were simulated using the SST k-ω turbulence model and SIMPLEC Pressure-Velocity coupling scheme. The pressure sensor were placed in mainly three positions, they are: bottom ring between runner and the wicket gates, downstream and left side in the draft tube cone below the runner. All the peak to peak values of pressure fluctuation meet signal probability of 97%. The frequency is gained by Fast Fourier Transform. The pressure fluctuations in different positions of the model in pump condition were showed when the guide vanes' opening angels were different. The simulation results confirmed the results gained in model tests. The results show that pressure fluctuations in design opening angle were much lower than those in off design opening angle. The main source of pressure fluctuations between runner and guide vanes is rotor stator interaction. While a lower frequency is the main frequency of the pressure fluctuation in draft tube.

  9. Determination of viscous pressure losssand resistance upstream from the choke point from breathing gases of different physical properties

    DEFF Research Database (Denmark)

    Pedersen, O.F.

    2007-01-01

      Determination of viscous pressure loss and resistance upstream from the choke point from breathing gases of different physical properties Ole F. Pedersen, Institute of Public Health, University of Aarhus, Denmark. AIM. To determine viscous pressure losses and resistances  upstream to CP...

  10. Comparison of Different Turbulence Models for Numerical Simulation of Pressure Distribution in V-Shaped Stepped Spillway

    Directory of Open Access Journals (Sweden)

    Zhaoliang Bai

    2017-01-01

    Full Text Available V-shaped stepped spillway is a new shaped stepped spillway, and the pressure distribution is quite different from that of the traditional stepped spillway. In this paper, five turbulence models were used to simulate the pressure distribution in the skimming flow regimes. Through comparing with the physical value, the realizable k-ε model had better precision in simulating the pressure distribution. Then, the flow pattern of V-shaped and traditional stepped spillways was given to illustrate the unique pressure distribution using realizable k-ε turbulence model.

  11. Studies on a CI engine using orange skin powder diesel solution with different fuel nozzle opening pressure

    Directory of Open Access Journals (Sweden)

    Purushothaman Krishnan

    2009-01-01

    Full Text Available Experiments have been conducted to study the effect of nozzle opening pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with orange skin powder diesel solution (OSPDS. Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and reduced emissions. In the present investigation the nozzle opening pressure was varied with 30% OSPDS and the combustion, performance, and emissions characteristics were studied and compared with those of diesel fuel. The different nozzle opening pressures studied were 215 bar, 235 bar, and 255 bar. The results showed that the cylinder pressure with 30% OSPDS at 235 bar fuel nozzle opening pressure, was higher than that of diesel fuel as well as at other nozzle opening pressures. Similarly, the ignition delay was longer with shorter combustion duration in case of 30% OSPDS at 235 bar nozzle opening pressure. The brake thermal efficiency was higher at 235 bar than that of other fuel nozzle opening pressures with OSPDS and lower than that of diesel fuel. The NOx emission was higher and HC and CO emissions were lower with 30% OSPDS at 235 bar. The smoke emission was marginally lower at 235 bar and marginally higher at 215 bar than diesel fuel. The performance of the engine at 235 bar nozzle opening pressure was better with reduction in emissions except NOx than other nozzle opening pressures.

  12. Geographic variation of melanisation patterns in a hornet species: genetic differences, climatic pressures or aposematic constraints?

    Directory of Open Access Journals (Sweden)

    Adrien Perrard

    Full Text Available Coloration of stinging insects is often based on contrasted patterns of light and black pigmentations as a warning signal to predators. However, in many social wasp species, geographic variation drastically modifies this signal through melanic polymorphism potentially driven by different selective pressures. To date, surprisingly little is known about the geographic variation of coloration of social wasps in relation to aposematism and melanism and to genetic and developmental constraints. The main objectives of this study are to improve the description of the colour variation within a social wasp species and to determine which factors are driving this variation. Therefore, we explored the evolutionary history of a polymorphic hornet, Vespa velutina Lepeletier, 1836, using mitochondrial and microsatellite markers, and we analysed its melanic variation using a colour space based on a description of body parts coloration. We found two main lineages within the species and confirmed the previous synonymy of V. auraria Smith, 1852, under V. velutina, differing only by the coloration. We also found that the melanic variation of most body parts was positively correlated, with some segments forming potential colour modules. Finally, we showed that the variation of coloration between populations was not related to their molecular, geographic or climatic differences. Our observations suggest that the coloration patterns of hornets and their geographic variations are determined by genes with an influence of developmental constraints. Our results also highlight that Vespa velutina populations have experienced several convergent evolutions of the coloration, more likely influenced by constraints on aposematism and Müllerian mimicry than by abiotic pressures on melanism.

  13. Resistance exercise with different volumes: blood pressure response and forearm blood flow in the hypertensive elderly

    Directory of Open Access Journals (Sweden)

    Brito AF

    2014-12-01

    Full Text Available Aline de Freitas Brito,1 Caio Victor Coutinho de Oliveira,2 Maria do Socorro Brasileiro-Santos,1 Amilton da Cruz Santos1 1Physical Education Department, 2Research Laboratory for Physical Training Applied to Performance and Health, Federal University of Paraíba, João Pessoa, Brazil Background: The purpose of this study was to evaluate the effect of two sessions of resistance exercise with different volumes on post-exercise hypotension, forearm blood flow, and forearm vascular resistance in hypertensive elderly subjects.Methods: The study was conducted with ten hypertensive elderly (65±3 years, 28.7±3 kg/m2 subjected to three experimental sessions, ie, a control session, exercise with a set (S1, and exercise with three sets (S3. For each session, the subjects were evaluated before and after intervention. In the pre-intervention period, blood pressure, forearm blood flow, and forearm vascular resistance were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same time period. Both S1 and S3 comprised a set of ten repetitions of ten exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (post-intervention in the supine position.Results: Post-exercise hypotension was greater in S3 than in S1 (systolic blood pressure, −26.5±4.2 mmHg versus −17.9±4.7 mmHg; diastolic blood pressure, −13.8±4.9 mmHg versus −7.7±5 mmHg, P<0.05. Similarly, forearm blood flow and forearm vascular resistance changed significantly in both sessions with an increase and decrease, respectively, that was more evident in S3 than in S1 (P<0.05.Conclusion: Resistance exercises with higher volume were more effective in causing post-exercise hypotension, being accompanied by an increase in forearm blood flow and a reduction of forearm vascular

  14. Gender Differences in Behavioral and Neural Responses to Unfairness Under Social Pressure

    OpenAIRE

    Zheng, Li; Ning, Reipeng; Li, Lin; Wei, Chunli; Cheng, Xuemei; Zhou, Chu; Guo, Xiuyan

    2017-01-01

    Numerous studies have revealed the key role of social pressure on individuals’ decision-making processes. However, the impact of social pressure on unfairness-related decision-making processes remains unclear. In the present study, we investigated how social pressure modulated men’s and women’s responses in an ultimatum game. Twenty women and eighteen men played the ultimatum game as responders in the scanner, where fair and unfair offers were tendered by proposers acting alone (low pressure)...

  15. Determinants of racial/ethnic differences in blood pressure management among hypertensive patients

    Directory of Open Access Journals (Sweden)

    Shaykevich Shimon

    2005-06-01

    Full Text Available Abstract Background Prior literature has shown that racial/ethnic minorities with hypertension may receive less aggressive treatment for their high blood pressure. However, to date there are few data available regarding the confounders of racial/ethnic disparities in the intensity of hypertension treatment. Methods We reviewed the medical records of 1,205 patients who had a minimum of two hypertension-related outpatient visits to 12 general internal medicine clinics during 7/1/01-6/30/02. Using logistic regression, we determined the odds of having therapy intensified by patient race/ethnicity after adjustment for clinical characteristics. Results Blacks (81.9% and Whites (80.3% were more likely than Latinos (71.5% to have therapy intensified (P = 0.03. After adjustment for racial differences in the number of outpatient visits and presence of diabetes, there were no racial differences in rates of intensification. Conclusion We found that racial/ethnic differences in therapy intensification were largely accounted for by differences in frequency of clinic visits and in the prevalence of diabetes. Given the higher rates of diabetes and hypertension related mortality among Hispanics in the U.S., future interventions to reduce disparities in cardiovascular outcomes should increase physician awareness of the need to intensify drug therapy more agressively in patients without waiting for multiple clinic visits, and should remind providers to treat hypertension more aggressively among diabetic patients.

  16. Investigation of the surface free energy of the ITO thin films deposited under different working pressure

    International Nuclear Information System (INIS)

    Özen, Soner; Pat, Suat; Korkmaz, Şadan; Şenay, Volkan

    2016-01-01

    This study discusses the influence of working pressure on the surface energy of the ITO thin films produced by radio frequency magnetron sputtering method. Optical tensiometer (Attension Theta Lite) is used for evaluating wetting behavior of the water droplet on the film surface and Equation of State method was selected to determine surface free energy for this study. Equation of state method does not divide the surface tension into different components such as polar, dispersive, acid-base. It is calculated the surfaces’ free energy measuring the contact angle with a single liquid. The surface free energy value was in the range of 15-31 mN/m. Also, the transmittances were determined in the wavelength range between 200 and 1000 nm using the UNICO 4802 UV-Vis double beam spectrophotometer. Transmittances of the produced ITO thin films are greater than %70 in the visible range.

  17. Investigation of the surface free energy of the ITO thin films deposited under different working pressure

    Energy Technology Data Exchange (ETDEWEB)

    Özen, Soner, E-mail: osoner@ogu.edu.tr; Pat, Suat; Korkmaz, Şadan [Eskişehir Osmangazi University, Physics Department, 26480 (Turkey); Şenay, Volkan [Eskişehir Osmangazi University, Physics Department, 26480 (Turkey); Bayburt University, Primary Science Education Department, 69000 (Turkey)

    2016-03-25

    This study discusses the influence of working pressure on the surface energy of the ITO thin films produced by radio frequency magnetron sputtering method. Optical tensiometer (Attension Theta Lite) is used for evaluating wetting behavior of the water droplet on the film surface and Equation of State method was selected to determine surface free energy for this study. Equation of state method does not divide the surface tension into different components such as polar, dispersive, acid-base. It is calculated the surfaces’ free energy measuring the contact angle with a single liquid. The surface free energy value was in the range of 15-31 mN/m. Also, the transmittances were determined in the wavelength range between 200 and 1000 nm using the UNICO 4802 UV-Vis double beam spectrophotometer. Transmittances of the produced ITO thin films are greater than %70 in the visible range.

  18. Intraocular pressure variation following retrobulbar anaesthesia among the different sex, age and ethnic groups in Malaysia.

    Science.gov (United States)

    Lee, F N; Kong, V Y; Lee, G P; Ho, K H; Choon, S C; Hoh, H B

    1999-12-01

    A total of 114 patients (48 Chinese, 34 Malay and 32 Indian) undergoing extracapsular cataract extraction (ECCE) with intraocular lens implantation, were enrolled. All were given 3 ml of local anaesthetic (combination of equal amounts of lignocaine 2% and bupivacaine 0.5%) using retrobulbar technique. Intraocular pressure (IOP) was measured at different time intervals; before, immediately after and 5 minutes after injection with Honan balloon compression. Mean IOP increased by 5.0 mmHg immediately after injection (p age groups, Chinese patients demonstrated the highest IOP rise following retrobulbar anaesthesia. This is the first study to demonstrate the influence of race in the IOP response with Chinese subjects having the highest IOP rise.

  19. Antioxidant White Grape Seed Phenolics: Pressurized Liquid Extracts from Different Varieties

    Directory of Open Access Journals (Sweden)

    Carmen Garcia-Jares

    2015-11-01

    Full Text Available Grape seeds represent a high percentage (20% to 26% of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain have been analyzed in order to characterize their polyphenolic content and antioxidant activity. Seeds of native (Albariño, Caiño, Godello, Loureiro, Torrontés, and Treixadura and non-native (Chardonnay, Gewurtzträminer, Pinot blanc, Pinot gris, and Riesling grape varieties have been considered. Low weight phenolics have been extracted by means of pressurized liquid extraction (PLE and further analyzed by LC-MS/MS. The results showed that PLE extracts, whatever the grape variety of origin, contained large amounts of polyphenols and high antioxidant activity. Differences in the varietal polyphenolic profiles were found, so a selective exploitation of seeds might be possible.

  20. Effects of two different fabrics on skin barrier function under real pressure conditions.

    Science.gov (United States)

    Schario, M; Tomova-Simitchieva, T; Lichterfeld, A; Herfert, H; Dobos, G; Lahmann, N; Blume-Peytavi, U; Kottner, J

    2017-05-01

    Pressure Ulcers (PUs) are a severe form of skin and soft tissue lesions, caused by sustained deformation. PU development is complex and depends on different factors. Skin structure and function change during prolonged loading on PU predilection sites and surfaces being in direct contact with skin are likely to have an impact as well. Little is known about the influence of fabrics on skin function under pressure conditions. To investigate skin responses to sustained loading in a sitting position and possible differences between two fabrics. Under controlled conditions 6 healthy females (median age 65.0 (61.0-67.8) years) followed a standardized immobilization protocol of a sitting position for 45 min on a spacer and on a cotton fabric. Before and after the loading period skin surface temperature, stratum corneum hydration, transepidermal water loss (TEWL), erythema, skin elasticity and 'relative elastic recovery' were measured at the gluteal areas. A 45 min sitting period caused increases of skin surface temperature and erythema independent of the fabric. Loading on spacer fabric showed a two times higher increase of TEWL compared to cotton. Stratum corneum hydration showed slight changes after loading, skin elasticity and 'relative elastic recovery' remained stable. Sitting on a hard surface causes skin barrier changes at the gluteal skin in terms of stratum corneum hydration and TEWL. These changes are influenced by the fabric which is in direct contact to the skin. There seems to be a dynamic interaction between skin and fabric properties especially in terms of temperature and humidity accumulation and transport. Copyright © 2016 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  1. Lack of blood pressure difference by race in professional American football players.

    Science.gov (United States)

    Tucker, Andrew M; Lincoln, Andrew E; Vogel, Robert A; Black, Henry R; Dunn, Reginald E; Wilson, Peter W F; Pellman, Elliot J

    2015-05-01

    Previous findings suggest that professional American football players have higher blood pressures (BP) and a higher prevalence of pre-hypertension and hypertension than the general population. We sought to determine whether race is associated with differences in BP and prevalence of pre-hypertension and hypertension among a large sample of professional football players. BP was measured at 2009 team mini-camps for 1484 black (n = 1007) and white (n = 477) players from 27 National Football League (NFL) teams. Players were categorized into three position groups based on body mass index (BMI). There was no racial difference in mean systolic or diastolic BP in any of the three position groups. There were no racial differences in prevalence of hypertension (99 [9.8%] black players vs. 39 [8.2%] white players; P = .353) or pre-hypertension (557 [55.3%] black players vs. 264 [55.3%] white players; P = 1.0). Contrary to findings in the general population, BP and prevalence of pre-hypertension/hypertension did not vary with race in a large population of active NFL players. Copyright © 2015 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  2. Management of high blood pressure in children: similarities and differences between US and European guidelines.

    Science.gov (United States)

    Brady, Tammy M; Stefani-Glücksberg, Amalia; Simonetti, Giacomo D

    2018-03-28

    Over the last several decades, many seminal longitudinal cohort studies have clearly shown that the antecedents to adult disease have their origins in childhood. Hypertension (HTN), which has become increasingly prevalent in childhood, represents one of the most important risk factors for cardiovascular diseases (CVD) such as heart disease and stroke. With the risk of adult HTN much greater when HTN is manifest in childhood, the future burden of CVD worldwide is therefore concerning. In an effort to slow the current trajectory, professional societies have called for more rigorous, evidence-based guideline development to aid primary care providers and subspecialists in improving recognition, diagnosis, evaluation, and treatment of pediatric HTN. In 2016 the European Society of Hypertension and in 2017 the American Academy of Pediatrics published updated guidelines for prevention and management of high blood pressure (BP) in children. While there are many similarities between the two guidelines, important differences exist. These differences, along with the identified knowledge gaps in each, will hopefully spur clinical researchers to action. This review highlights some of these similarities and differences, focusing on several of the more important facets regarding prevalence, prevention, diagnosis, management, and treatment of childhood HTN.

  3. The Effect of Different Doses of Aerobic Exercise Training on Exercise Blood Pressure in Overweight and Obese Postmenopausal Women

    Science.gov (United States)

    Swift, Damon L.; Earnest, Conrad P.; Katzmarzyk, Peter T.; Rankinen, Tuomo; Blair, Steven N.; Church, Timothy S.

    2011-01-01

    Objective Abnormally elevated exercise blood pressure is associated with increased risk of cardiovascular disease. Aerobic exercise training has been shown to reduce exercise blood pressure. However, it is unknown if these improvements occur in a dose dependent manner. The purpose of the present study is to determine the effect of different doses of aerobic exercise training on exercise blood pressure in obese postmenopausal women. Methods Participants (n=404) were randomized to one of 4 groups: 4, 8, or 12 kilocalories per kilogram of energy expenditure per week (kcal/kg/week) or the non-exercise control group for 6 months. Exercise blood pressure was obtained during the 50 watts stage of a cycle ergometer maximal exercise test. Results There was a significant reduction in systolic blood pressure at 50 watts in the 4 kcal/kg/week (−10.9 mmHg, pexercise training dose significantly reduced diastolic blood pressure (−4.3 mmHg, p= 0.033) compared to control. Additionally, resting blood pressure was not altered following exercise training (p>0.05) compared to control, and was not associated with changes in exercise systolic (r=0.09, p=0.09) or diastolic (r=0.10, p=0.08) blood pressure. Conclusions Aerobic exercise training reduces exercise blood pressure and may be more modifiable than changes in resting blood pressure. A high dose of aerobic exercise is recommended to successfully reduce both exercise systolic and diastolic blood pressure, and therefore may attenuate the CVD risk associated with abnormally elevated exercise blood pressure. PMID:22547251

  4. The effects of different lying positions on interface pressure, skin temperature, and tissue blood flow in nursing home residents.

    Science.gov (United States)

    Källman, Ulrika; Engström, Maria; Bergstrand, Sara; Ek, Anna-Christina; Fredrikson, Mats; Lindberg, Lars-Göran; Lindgren, Margareta

    2015-03-01

    Although repositioning is considered an important intervention to prevent pressure ulcers, tissue response during loading in different lying positions has not been adequately explored. To compare the effects of different lying positions on interface pressure, skin temperature, and tissue blood flow in nursing home residents. From May 2011 to August 2012, interface pressure, skin temperature, and blood flow at three tissue depths were measured for 1 hr over the sacrum in 30° supine tilt and 0° supine positions and over the trochanter major in 30° lateral and 90° lateral positions in 25 residents aged 65 years or older. Measurement of interface pressure was accomplished using a pneumatic pressure transmitter connected to a digital manometer, skin temperature using a temperature sensor, and blood flow using photoplethysmography and laser Doppler flowmetry. Interface pressure was significantly higher in the 0° supine and 90° lateral positions than in 30° supine tilt and 30° lateral positions. The mean skin temperature increased from baseline in all positions. Blood flow was significantly higher in the 30° supine tilt position compared to the other positions. A hyperemic response in the post pressure period was seen at almost all tissue depths and positions. The 30° supine tilt position generated less interface pressure and allowed greater tissue perfusion, suggesting that this position is the most beneficial. © The Author(s) 2014.

  5. Interankle systolic blood pressure difference and renal outcomes in patients with chronic kidney disease.

    Science.gov (United States)

    Chen, Szu-Chia; Tsai, Yi-Chun; Huang, Jiun-Chi; Lee, Su-Chu; Chang, Jer-Ming; Hwang, Shang-Jyh; Chen, Hung-Chun

    2016-05-01

    Interankle blood pressure (BP) difference has been associated with peripheral artery disease and adverse cardiovascular outcomes. However, the relationship between interankle BP difference and renal outcomes in chronic kidney disease (CKD) has never been evaluated. The purpose of this study was to determine whether interankle BP difference is associated with the rate of renal function decline and progression to renal end points in patients with stage 3-5 CKD. We enrolled 144 patients with CKD from one regional hospital. The BP in four limbs was simultaneously measured using an ABI-form device. The decline in renal function was evaluated using an estimated glomerular filtration rate (eGFR) slope. Rapid renal progression was defined as an eGFR slope < -3 mL/min per 1.73 m(2) per year. The renal end points were defined as ≥ 25% decline in eGFR or commencement of dialysis during the follow-up period. During a mean follow-up period of 3.1 years, 90 patients (62.5%) reached renal end points. Multivariate analysis showed that an increased interankle systolic BP difference (per 5 mmHg) was associated with a worse eGFR slope (regression β, -0.292; 95% confidence interval [CI], -0.482 to -0.102; P = 0.003), rapid renal progression (odds ratio, 1.189; 95% CI, 1.015-1.394; P = 0.032), and an increased risk of progression to renal end points (hazard ratio, 1.126; 95% CI, 1.052-1.204, P = 0.001). Interankle systolic BP difference was associated with rapid renal progression and progression to renal end points in patients with stage 3-5 CKD in our study. © 2015 Asian Pacific Society of Nephrology.

  6. Synthetic oligomer analysis using atmospheric pressure photoionization mass spectrometry at different photon energies

    Energy Technology Data Exchange (ETDEWEB)

    Desmazières, Bernard [Global Bioenergies, 5 rue Henri Desbruyeres, 91030 Evry (France); Legros, Véronique [CNRS, UMR8587, Université d’Evry-Val-d’Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, F-91025 Evry (France); Giuliani, Alexandre [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, 91192 Gif-sur-Yvette (France); UAR1008, CEPIA, INRA, Rue de la Geraudiere, F-44316 Nantes (France); Buchmann, William, E-mail: william.buchmann@univ-evry.fr [CNRS, UMR8587, Université d’Evry-Val-d’Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, F-91025 Evry (France)

    2014-01-15

    Graphical abstract: Atmospheric pressure photoIonization mass spectra of synthetic oligomers were recorded in the negative mode by varying the photon energy using synchrotron radiation. Photon energy required for an efficient ionization of the polymer was correlated to ionization potential of the solvent (for example 9.4 eV for tetrahydrofuran). -- Highlights: •Atmospheric pressure photoionization was performed using synchrotron radiation. •Photoionization of oligomers in THF with 10% CH{sub 2}Cl{sub 2} produces intact [M + Cl]{sup −} ions. •The photon energy required corresponds to ionization potential of the solvent. •Polymer distributions depend on source parameters such T °C and applied voltages. •Liquid chromatography was coupled to MS using an APPI interface for polymer analysis. -- Abstract: Atmospheric pressure photoionization (APPI) followed by mass spectrometric detection was used to ionize a variety of polymers: polyethylene glycol, polymethyl methacrylate, polystyrene, and polysiloxane. In most cases, whatever the polymer or the solvent used (dichloromethane, tetrahydrofuran, hexane, acetone or toluene), only negative ion mode produced intact ions such as chlorinated adducts, with no or few fragmentations, in contrast to the positive ion mode that frequently led to important in-source fragmentations. In addition, it was shown that optimal detection of polymer distributions require a fine tuning of other source parameters such as temperature and ion transfer voltage. Series of mass spectra were recorded in the negative mode, in various solvents (dichloromethane, tetrahydrofuran, hexane, toluene, and acetone), by varying the photon energy from 8 eV up to 10.6 eV using synchrotron radiation. To these solvents, addition of a classical APPI dopant (toluene or acetone) was not necessary. Courtesy of the synchrotron radiation, it was demonstrated that the photon energy required for an efficient ionization of the polymer was correlated to the

  7. Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index

    Directory of Open Access Journals (Sweden)

    Moreira Leila B

    2010-11-01

    Full Text Available Abstract Background Blood pressure (BP variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM. We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI. Methods and Results In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time, standard deviation (SD of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (≤ 0.90 or ≥ 1.40 was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007. In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04. In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P Conclusion Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.

  8. Pressure transient analysis in single and two-phase water by finite difference methods

    International Nuclear Information System (INIS)

    Berry, G.F.; Daley, J.G.

    1977-01-01

    An important consideration in the design of LMFBR steam generators is the possibility of leakage from a steam generator water tube. The ensuing sodium/water reaction will be largely controlled by the amount of water available at the leak site, thus analysis methods treating this event must have the capability of accurately modeling pressure transients through all states of water occurring in a steam generator, whether single or two-phase. The equation systems of the present model consist of the conservation equations together with an equation of state for one-dimensional homogeneous flow. These equations are then solved using finite difference techniques with phase considerations and non-equilibrium effects being treated through the equation of state. The basis for water property computation is Keenan's 'fundamental equation of state' which is applicable to single-phase water at pressures less than 1000 bars and temperatures less than 1300 0 C. This provides formulations allowing computation of any water property to any desired precision. Two-phase properties are constructed from values on the saturation line. The use of formulations permits the direct calculation of any thermodynamic property (or property derivative) to great precision while requiring very little computer storage, but does involve considerable computation time. For this reason an optional calculation scheme based on the method of 'transfinite interpolation' is included to give rapid computation in selected regions with decreased precision. The conservation equations were solved using the second order Lax-Wendroff scheme which includes wall friction, allows the formation of shocks and locally supersonic flow. Computational boundary conditions were found from a method-of-characteristics solution at the reservoir and receiver ends. The local characteristics were used to interpolate data from inside the pipe to the boundary

  9. Electrocardiographic, echocardiographic, and indirect blood pressure evaluation in dogs subjected to different sedation protocols

    Directory of Open Access Journals (Sweden)

    Helena Mondardo Cardoso

    Full Text Available ABSTRACT: The present study aimed to evaluate the effects of different sedation protocols on blood pressure and echocardiographic and electrocardiographic parameters in dogs. In total, 24 male mixed-breed dogs with a mean weight of 9.87±3.0kg were used.Animals were randomly divided into four groups (n=6, which were subjected to sedation using the following protocols: acepromazine (0.05mgkg-1 and butorphanol (0.3mgkg-1 (AB; acepromazine (0.05mgkg-1and methadone (0.5mgkg-1 (AM; acepromazine (0.03mgkg-1, methadone (0.5mgkg-1, and midazolam (0.3mgkg-1(MAM; and methadone only (0.5mgkg-1 (M. Indirect blood pressure (BP measurements and computerized electrocardiography (ECG and echocardiography (ECO were performed immediately before the application of the sedation protocol (baseline, and the same evaluations were repeated after 15 minutes. BP decreased in groups AB, MAM, and AM compared to baseline values. Electrocardiographic measurements showed decreased heart rates (HRs after sedation in all groups, and bradycardia was observed after sedation in two dogs from group M and one animal from group AM. The P-wave duration increased after sedation in groups AM and M. After sedation, no changes in cardiac dimensions were revealed byECO.Fractional shortening (FS decreased after sedation in the AM group, and dogs from group AB exhibited a smaller decrease in FS compared with the other groups. The cardiac index (CI was lower in groups AM and M than in the other groups. Animals from group AB were less resistant to examination and exhibited the most favorable sedation scores. It was concluded that the combination of acepromazine and butorphanol was the best sedation protocol for performing echocardiogram measurementsbecause dogs were less resistant to examinations and echocardiographic parameters of FS and CI remained stable.

  10. Association between general and abdominal obesity with high blood pressure: difference between genders.

    Science.gov (United States)

    Silva, Alison O; Silva, Micaelly V; Pereira, Lisley K N; Feitosa, Wallacy M N; Ritti-Dias, Raphael M; Diniz, Paula R B; Oliveira, Luciano M F T

    2016-01-01

    To assess the association between general and abdominal obesity with high blood pressure in adolescents of both genders from the public school system. This was an epidemiological, descriptive, exploratory study, with a quantitative approach and local scope whose sample consisted of 481 high school students (aged 14-19), selected by using a random cluster sampling strategy. Blood pressure was measured through the use of automated monitor and was considered high when the pressure values were at or above the 95th percentile. The analyses were performed using the chi-squared test and binary logistic regression. The prevalence of high blood pressure was 6.4%, and it was higher among boys (9.0% vs. 4.7%, phigh blood pressure was associated with general (OR=6.4; phigh blood pressure only in boys, regardless of age. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  11. Blood pressure response during resistance training of different work to rest ratio.

    Science.gov (United States)

    Paulo, Anderson Caetano; Tricoli, Valmor; Queiroz, Andréia C C; Laurentino, Gilberto; Forjaz, Cláudia L M

    2017-06-22

    Changes in the work to rest ratio (W:R) of resistance training protocols (RTP) (i.e. decreasing work and/or increasing rest) reduce the marked elevation in blood pressure (BP) that occurs during RTP execution. However, whether changes in RTP protocol structure without changing W:R can change BP responses to RTP is unknown. To investigate the effect of different structures of rest intervals and number of repetitions per set on BP response among RTP equated and nonequated for W:R, 20 normotensive participants (25±4 years) performed four different RTP of the leg extension exercise with the same work but different W:R structures. Two protocols followed the recommendations for cardiovascular disorders: I) HIGHW:R-3x15:44s - 3x15:44s (setxreps:rest between sets), which has high W:R (45reps:88s) and II) LOWW:R-3x15:88s - 3x15:88s, which has low W:R (45reps:176s). The other two protocols were W:R-equated to LOWW:R (45reps:176s): III) LOWW:R-9x5:22s and IV) LOWW:R-45x1:4s. Systolic BP (ΔSBP) and diastolic BP (ΔDBP) were assessed by finger photoplethysmography. There were significant main effects for ΔSBP following RTP (p LOWW:R-45x1:4s > LOWW:R-9x5:22s (+87±5 and +84±5 vs. +61±4 vs. 57±4 mmHg). For ΔDBP, there was a significant interaction between RTP and moment (p LOWW:R-3x15:88s > LOWW:R-45x1:4s > LOWW:R-9x5:22s (+53±5 vs. +49±5 vs. +44±4 vs. +38±3 mmHg). R-3x15:44s produced the highest increase in ΔDBP and LOWW:R-9x5:22s produced the lowest increase in ΔSBP and ΔDBP. Our findings may help the development of RT protocols that may mitigate pressure peaks without changing important exercise variables (i.e. volume or duration).

  12. How does low temperature coupled with different pressures affect initiation mechanisms and subsequent decompositions in nitramine explosive HMX?

    Science.gov (United States)

    Wu, Qiong; Xiong, Guolin; Zhu, Weihua; Xiao, Heming

    2015-09-21

    We have performed ab initio molecular dynamics simulations to study coupling effects of temperature (534-873 K) and pressure (1-20 GPa) on the initiation mechanisms and subsequent chemical decompositions of nitramine explosive 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). A new initiation decomposition mechanism of HMX was found to be the unimolecular C-H bond breaking, and this mechanism was independent of the coupling effects of different temperatures and pressures. The formed hydrogen radicals could promote subsequent decompositions of HMX. Subsequent decompositions were very sensitive to the pressure at low temperatures (534 and 608 K), while the temperature became the foremost factor that affected the decomposition at a high temperature (873 K) instead of the pressure. Our study may provide a new insight into understanding the coupling effects of the temperature and pressure on the initiation decomposition mechanisms of nitramine explosives.

  13. Evaluation of the pressure difference across the core during PWR-LOCA reflood phase

    International Nuclear Information System (INIS)

    Iguchi, Tadashi; Murao, Yoshio

    1979-03-01

    The flooding rate of the core influences largely cooling of the core during the reflood phase of a PWR-LOCA. Since the void fraction of two-phase flow in the core is important determining the flooding rate, it is essential to examine this void fraction. The void fraction in the core during the reflood phase obtained by experiment was compared with those predicted by the correlations respectively of Akagawa, Nicklin, Zuber, Yeh, Griffice, Behringer and Jhonson. Only Yeh's correlation was found to be usable for the purpose. The pressure difference of the core during the reflood phase was calculated by reflood analyzing code REFLA-1D using Yeh's correlation. Following are the results: (1) During the steady-state period after quenching of the heaters, the prediction agrees within +-15% with the experiment. (2) During the transient period when the quench front is advancing, the prediction is not in agreement with the experiment, the difference being about +-40%. Influence of the advancing quench front upon the void fraction in the core must further be studied. (author)

  14. Pigmented and albino rats differ in their responses to moderate, acute and reversible intraocular pressure elevation.

    Science.gov (United States)

    Gurdita, Akshay; Tan, Bingyao; Joos, Karen M; Bizheva, Kostadinka; Choh, Vivian

    2017-06-01

    To compare the electrophysiological and morphological responses to acute, moderately elevated intraocular pressure (IOP) in Sprague-Dawley (SD), Long-Evans (LE) and Brown Norway (BN) rat eyes. Eleven-week-old SD (n = 5), LE (n = 5) and BN (n = 5) rats were used. Scotopic threshold responses (STRs), Maxwellian flash electroretinograms (ERGs) or ultrahigh-resolution optical coherence tomography (UHR-OCT) images of the rat retinas were collected from both eyes before, during and after IOP elevation of one eye. IOP was raised to ~35 mmHg for 1 h using a vascular loop, while the other eye served as a control. STRs, ERGs and UHR-OCT images were acquired on 3 days separated by 1 day of no experimental manipulation. There were no significant differences between species in baseline electroretinography. However, during IOP elevation, peak positive STR amplitudes in LE (mean ± standard deviation 259 ± 124 µV) and BN (228 ± 96 µV) rats were about fourfold higher than those in SD rats (56 ± 46 µV) rats (p = 0.0002 for both). Similarly, during elevated IOP, ERG b-wave amplitudes were twofold higher in LE and BN rats compared to those of SD rats (947 ± 129 µV and 892 ± 184 µV, vs 427 ± 138 µV; p = 0.0002 for both). UHR-OCT images showed backward bowing in all groups during IOP elevation, with a return to typical form about 30 min after IOP elevation. Differences in the loop-induced responses between the strains are likely due to different inherent retinal morphology and physiology.

  15. Ethnic differences in the effect of environmental stressors on blood pressure and hypertension in the Netherlands

    Directory of Open Access Journals (Sweden)

    Lindeman Ellen

    2007-06-01

    Full Text Available Abstract Background Evidence strongly suggests that the neighbourhood in which people live influences their health. Despite this, investigations of ethnic differences in cardiovascular risk factors have focused mainly on individual-level characteristics. The main purpose of this study was to investigate associations between neighbourhood-level environmental stressors (crime, housing density, nuisance from alcohol and drug misuse, quality of green space and social participation, and blood pressure (BP and hypertension among different ethnic groups. Methods Individual data from the Amsterdam Health Survey 2004 were linked to data on neighbourhood stressors creating a multilevel design for data analysis. The study sample consisted of 517 Dutch, 404 Turkish and 365 Moroccans living in 15 neighbourhoods in Amsterdam, the Netherlands. Results Amongst Moroccans, high density housing and nuisance from drug misuse were associated with a higher systolic BP, while high quality of green space and social participation were associated with a lower systolic BP. High level of nuisance from drug misuse was associated with a higher diastolic BP. High quality of green space was associated with lower odds of hypertension. Amongst Turkish, high level of crime and nuisance from motor traffic were associated with a higher diastolic BP. Similar associations were observed among the Dutch group but none of the differences were statistically significant. Conclusion The study findings show that neighbourhood-level stressors are associated with BP in ethnic minority groups but were less evident in the Dutch group. These findings might imply that the higher BP levels found in some ethnic minority groups might be partly due to their greater susceptibility to the adverse neighbourhood environment in which many ethnic minority people live. Primary prevention measures targeting these neighbourhood stressors may have an impact in reducing high BP related morbidity and mortality

  16. Resuscitation strategies with different arterial pressure targets after surgical management of traumatic shock.

    Science.gov (United States)

    Bai, Xiaowu; Yu, Wenkui; Ji, Wu; Duan, Kaipeng; Tan, Shanjun; Lin, Zhiliang; Xu, Lin; Li, Ning

    2015-04-20

    Hypotensive fluid resuscitation has a better effect before and during surgical intervention for multiple trauma patients with haemorrhagic shock. However, it is questionable whether hypotensive fluid resuscitation is suitable after surgical intervention for these patients, and whether resuscitation with different mean arterial pressure (MAP) targets after surgical intervention can obtain different results. The aim of this study was to investigate these questions and to explore the underlying mechanisms. A total of 30 anesthetized piglets were randomly divided into 3 groups (n = 10 per group): low MAP, middle MAP, and high MAP, which had MAP targets of 60, 80, and 100 mmHg, respectively. All animals underwent femur fracture, intestine and liver injury, haemorrhagic shock, early hypotensive resuscitation, and surgical intervention. Then, the animals received fluid resuscitation with different MAP targets as mentioned above for 24 hours. Hemodynamic parameters and vital organ functions were evaluated. Fluid resuscitation in the 80 mmHg MAP group maintained haemodynamic stability, tissue perfusion, and organ function better than that in the other groups. The 60 mmHg MAP group presented with profound metabolic acidosis and organ histopathologic damage. In addition, animals in the 100 mmHg MAP group exhibited severe tissue oedema, organ function failure, and histopathologic damage. In our porcine model of resuscitation, targeting high MAP by fluid administration alone resulted in a huge increase in the infusion volume, severe tissue oedema, and organ dysfunction. Meanwhile, targeting low MAP resulted in persistent tissue hypoperfusion and metabolic stress. Hence, a resuscitation strategy of targeting appropriate MAP might be compatible with maintaining haemodynamic stability, tissue perfusion, and organ function.

  17. Response of blood pressure to maximum exercise in hypertensive patients under different therapeutic programs

    Directory of Open Access Journals (Sweden)

    Carreira Maria Angela Magalhães de Queiroz

    2000-01-01

    Full Text Available OBJECTIVE: To evaluate the behavior of blood pressure during exercise in patients with hypertension controlled by frontline antihypertension drugs. METHODS: From 979ergometric tests we retrospectively selected 49 hipertensive patients (19 males. The age was 53±12 years old and normal range rest arterial pressure ( or = 10 mmHg/MET; or increase of diastolic pressure greater than 15 mmHg. RESULTS: Physiologic response of arterial blood pressure occurred in 50% of patients on beta blockers, the best one (p<0.05, in 36% and 31% on calcium antagonists and on diuretics, respectively, and in 20% on angiotensin converting enzyme inhibitor, the later the leastr one (p<0.05. CONCLUSION: Beta-blockers were more effective than calcium antagonists, diuretics and angiotensin-converting enzyme inhibitors in controlling blood pressure during exercise, and angiotensin converting enzyme inhibitors the least effective drugs.

  18. Differences in perioperative femoral and radial arterial blood pressure in neonates and infants undergoing cardiac surgery requiring cardiopulmonary bypass

    OpenAIRE

    Cho, Hwa Jin; Lee, Sang Hoon; Jeong, In Seok; Yoon, Nam Sik; Ma, Jae Sook; Ahn, Byoung Hee

    2018-01-01

    Abstract Objective: Several reports claim that blood pressure (BP) in the radial artery may underestimate the accurate BP in critically ill patients. Here, the authors evaluated differences in mean blood pressure (MBP) between the radial and femoral artery during pediatric cardiac surgery to determine the effectiveness of femoral arterial BP monitoring. Method: The medical records of children under 1 year of age who underwent open-heart surgery between 2007 and 2013 were retrospectively rev...

  19. AUTOMATIC CONTROL SYSTEM OF THE DIFFERENCE BETWEEN DISCHARGE AND SUCTION PRESSURES OF THE HEAT PUMP STATION COMPRESSOR

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2009-04-01

    Full Text Available Possibility of realization is shown and the control system of a difference of pressure between an exit and an input of the compressor of the heat pump on carbon dioxide working at variable thermal load, and discharge and suction pressures by means of two control valves connected in series is developed. On an example a flow coefficient calculation procedure of control valves is shown.

  20. Emergence and stability of high-pressure resistance in different food-borne pathogens.

    Science.gov (United States)

    Vanlint, Dietrich; Rutten, Nele; Michiels, Chris W; Aertsen, Abram

    2012-05-01

    High hydrostatic pressure (HHP) processing is becoming a valuable nonthermal food pasteurization technique, although there is reasonable concern that bacterial HHP resistance could compromise the safety and stability of HHP-processed foods. While the degree of natural HHP resistance has already been shown to vary greatly among and within bacterial species, a still unresolved question remains as to what extent different food-borne pathogens can actually develop HHP resistance. In this study, we therefore examined and compared the intrinsic potentials for HHP resistance development among strains of Escherichia coli, Shigella flexneri, Salmonella enterica serovars Typhimurium and Enteritidis, Yersinia enterocolitica, Aeromonas hydrophila, Pseudomonas aeruginosa, and Listeria innocua using a selective enrichment approach. Interestingly, of all strains examined, the acquisition of extreme HHP resistance could be detected in only some of the E. coli strains, indicating that a specific genetic predisposition might be required for resistance development. Furthermore, once acquired, HHP resistance proved to be a very stable trait that was maintained for >80 generations in the absence of HHP exposure. Finally, at the mechanistic level, HHP resistance was not necessarily linked to derepression of the heat shock genes and was not related to the phenomenon of persistence.

  1. Dynamic blood pressure changes and recovery under different work shifts in young women.

    Science.gov (United States)

    Lo, Shih-Hsiang; Liau, Chiau-Suong; Hwang, Jing-Shiang; Wang, Jung-Der

    2008-07-01

    Some studies have reported that shift work can affect blood pressure (BP), but few have studied recovery from BP changes occurring during different shifts. We recruited 16 young female nurses working rotating shifts and six working the regular day shift. All received repeated ambulatory BP monitoring (ABPM) during their workdays and following day off. Our linear mixed-effect model showed that both systolic and diastolic BPs were significantly decreased during sleeping period and significantly increased while on working period, on a work day, but increased during sleeping period after a night shift or evening shift. BP measurements that changed after evening shift usually returned to baseline on consecutive off-duty day after day shift, but they did not completely return to baseline after a night shift (P working rotating shifts had at least changed once in dipper/nondipper status. The rates of change in dipper/nondipper status between work day and off-duty day were 33, 44, 50, and 38% for nurses worked in outpatient clinic, night shift, evening shift, and day shift, respectively. Shift work is significantly associated with BP and possibly dipper/nondipper status in young female nurses. Except for those working night shifts, BP levels returned to baseline the off-duty day after day shift. We recommend that potential influence of shift work be considered when evaluating a person's BP.

  2. Pressure ulcer risk assessment and prevention: what difference does a risk scale make? A comparison between Norway and Ireland.

    Science.gov (United States)

    Johansen, E; Moore, Z; van Etten, M; Strapp, H

    2014-07-01

    To explore similarities and differences in nurses' views on risk assessment practices and preventive care activities in a context where patients' risk of developing pressure ulcers is assessed using clinical judgment (Norway) and a context where patients' risk of developing pressure ulcers is assessed using a formal structured risk assessment combined with clinical judgement (Ireland). A descriptive, qualitative design was employed across two different care settings with a total of 14 health care workers, nine from Norway and five from Ireland. Regardless of whether risk assessment was undertaken using clinical judgment or formal structured risk assessment, identified risk factors, at risk patients and appropriate preventive initiatives discussed by participant were similar across care settings. Furthermore, risk assessment did not necessarily result in the planning and implementation of appropriate pressure ulcer prevention initiatives. Thus, in this instance, use of a formal risk assessment tool does not seem to make any difference to the planning, initiation and evaluation of pressure ulcer prevention strategies. Regardless of the method of risk assessment, patients at risk of developing pressure ulcers are detected, suggesting that the practice of risk assessment should be re-evaluated. Moreover, appropriate preventive interventions were described. However, the missing link between risk assessment and documented care planning is of concern and barriers to appropriate pressure ulcer documentation should be explored further. This work is partly funded by a research grant from the Norwegian Nurses Organisation (NNO) (Norsk Sykepleierforbund NSF) in 2012. The authors have no conflict of interest to declare.

  3. Ethnic differences of intraocular pressure and central corneal thickness: the Singapore Epidemiology of Eye Diseases study.

    Science.gov (United States)

    Chua, Jacqueline; Tham, Yih Chung; Liao, Jiemin; Zheng, Yingfeng; Aung, Tin; Wong, Tien Yin; Cheng, Ching-Yu

    2014-10-01

    To determine the ethnic differences in the distribution of intraocular pressure (IOP) and central corneal thickness (CCT) in a multi-ethnic Asian population by self-reported ethnicity and genetic ancestry. Population-based, cross-sectional study. A total of 10 033 adults (3353 Chinese, 3280 Malays, and 3400 Indians) aged >40 years. Participants underwent standardized systemic and ocular examinations and interviewer-administered questionnaires for risk factor assessment. The IOP readings were obtained by Goldmann applanation tonometry (Haag-Streit, Konig, Switzerland) before pupil dilation. The CCT was measured with ultrasound pachymetry. Genetic ancestry was derived using principal component (PC) analysis. Regression models were used to investigate the association of IOP and CCT with potential risk factors and genetic ancestry. Intraocular pressure and CCT. After excluding participants with a history of glaucoma surgery or medication, refractive surgery, corneal edema, or corneal dystrophy, IOP and CCT readings were available for 3251 Chinese, 3232 Malays, and 3317 Indians. The mean IOP readings in the Chinese, Malay, and Indian participants were 14.3±3.1, 15.3±3.7, and 15.8±2.9 mmHg, respectively (P Chinese, 6.2% in Malays, and 4% in Indians (P Malay and Indian participants on average had 0.81 and 1.43 mmHg higher IOP levels, respectively, than Chinese (P Chinese, 540.9±33.6 μm in Malays, and 540.4±33.6 μm in Indians (P Chinese, 68.5% in Malays, and 66.2% in Indians (P Chinese have the thickest CCT but lowest IOP among the 3 major ethnic groups. In addition, there is a higher proportion of Malays with IOP ≥21 mmHg and CCT Chinese or Indians. This disparity across ethnic groups should be taken into account by future studies investigating IOP and CCT as risk factors or diagnostic tests for glaucoma in Asian populations. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  4. Analysis of Difference in Center-of-Pressure Positions Between Experts and Novices During Asymmetric Lifting

    Science.gov (United States)

    Yamada, Kenji; Kido, Michiko; Okada, Shima; Nomura, Taishin; Ohno, Yuko

    2016-01-01

    Although numerous studies have analyzed the relationship between manual material handling (MMH) and the forces acting on the lumbar spine, the difference in the MMH between experts and novices through the analysis of measured data has not been well studied. The purpose of this paper was to analyze the difference in the MMH positions between ten skilled experts working at a freight transport company (Group 1) and five unskilled novices without any experience (Group 2) during asymmetric lifting. All the human subjects performed asymmetric lifting experiments with closed eyes; the experiments involved moving loads (6 and 18 kg) to the left side. Time series data of the vertical ground reaction force were measured, using a Wii Balance Board, and then, the center-of-pressure (CoP) trajectories were calculated. The balance board was used for the measurement, because it was reliable, inexpensive, and portable and provided good repeatability even on rough surfaces, and all the information pertaining to the load and worker under various conditions was captured without any omissions. Under the 18 kg load condition, the CoP positions for Group 2 were located on the same side during left asymmetric lifting; however, those for Group 1 were located on the opposite side during left asymmetric lifting (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$P CoP positions were located on the opposite side (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$P CoP positions between the two different groups could be attributed to the difference in the hip positions. Most skilled experts position their hips in

  5. New pulse wave measurement method using different hold-down wrist pressures according to individual patient characteristics.

    Science.gov (United States)

    Yoo, Seong Ki; Shin, Ki Young; Lee, Tae Bum; Jin, Seung Oh

    2013-01-01

    In traditional Chinese and Korean medicine, doctors first observe a patient's pulse by gently and strongly pressing their fingers onto the wrist, and then make a diagnosis based on the observed pulse waves. The most common method to implement this diagnostic technique is to mechanically extract the pulse waves by applying a fixed range of pressures for all patients. However, this method does not consider the patients individual characteristics such as age, sex, and skin thickness. In the present study, we propose a new method of pulse wave extraction that incorporates the personal characteristics of the patients. This method measures the pulse wave signal at varying hold-down pressures, rather than applying a fixed hold-down pressure for all patients. To compare this new technique with existing methods, we extracted pulse waves from 20 subjects, and then determined the actual applied pressure at each step, the coefficient of floating and sinking pulse (CFS), and the distinction of floating/sinking pulse for each group. Consequently, each subject had a different pressure range in our proposed method, whereas all subjects had a similar pressure range in the existing method. Four of 20 subjects exhibited different floating/sinking pulse patterns due to the value of the first pressure step and the range of hold-down pressures. These four subjects were categorized as overweight based on BMI. In addition, the moving distance of the proposed method was longer than the existing method (p = 0.003, paired t-test), and the correlation coefficient between CFS values of two different methods was 0.321, indicating that there was no correlation.

  6. Investigation of a mutual interaction force at different pressure amplitudes in sulfuric acid

    International Nuclear Information System (INIS)

    Rezaee, Nastaran; Sadighi-Bonabi, Rasoul; Mirheydari, Mona; Ebrahimi, Homa

    2011-01-01

    This paper investigates the secondary Bjerknes force for two oscillating bubbles in various pressure amplitudes in a concentration of 95% sulfuric acid. The equilibrium radii of the bubbles are assumed to be smaller than 10 μm at a frequency of 37 kHz in various strong driving acoustical fields around 2.0 bars (1 bar=10 5 Pa). The secondary Bjerknes force is investigated in uncoupled and coupled states between the bubbles, with regard to the quasi-adiabatic model for the bubble interior. It finds that the value of the secondary Bjerknes force depends on the driven pressure of sulfuric acid and its amount would be increased by liquid pressure amplitude enhancement. The results show that the repulsion area of the interaction force would be increased by increasing the driven pressure because of nonlinear oscillation of bubbles. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. Effects of pressure and temperature on thermal contact resistance between different materials

    Directory of Open Access Journals (Sweden)

    Zhao Zhe

    2015-01-01

    Full Text Available To explore whether pressure and temperature can affect thermal contact resistance, we have proposed a new experimental approach for measurement of the thermal contact resistance. Taking the thermal contact resistance between phenolic resin and carbon-carbon composites, cuprum, and aluminum as the examples, the influence of the thermal contact resistance between specimens under pressure is tested by experiment. Two groups of experiments are performed and then an analysis on influencing factors of the thermal contact resistance is presented in this paper. The experimental results reveal that the thermal contact resistance depends not only on the thermal conductivity coefficient of materials, but on the interfacial temperature and pressure. Furthermore, the thermal contact resistance between cuprum and aluminum is more sensitive to pressure and temperature than that between phenolic resin and carbon-carbon composites.

  8. Evidence for skill level differences in the thought processes of golfers during high and low pressure situations.

    Directory of Open Access Journals (Sweden)

    Amy Elizabeth Whitehead

    2016-01-01

    Full Text Available Two studies examined differences in the cognition of golfers with differing levels of expertise in high and low pressure situations. In study 1, six high skill and six low skill golfers performed six holes of golf, while verbalizing their thoughts using Think Aloud (TA protocol. Higher skilled golfers’ cognitive processes centered more on planning in comparison to lower skilled golfers. Study 2 investigated whether thought processes of golfers changed in response to competitive pressure. Eight high skill and eight moderate skilled golfers, completed a practice round and a competition round whilst verbalizing thoughts using TA. To create pressure in the competition condition, participants were instructed that monetary prizes would be awarded to the top three performers and scores of all golfers would be published in a league table in the club house. When performing under competitive pressure, it was found that higher skilled golfers were more likely to verbalize technical rules compared to practice conditions, especially during putting performance. This shift in cognition toward more technical aspects of motor performance was strongly related to scores on the Decision Specific Reinvestment Scale, suggesting individuals with a higher propensity for reinvestment show the largest changes in cognition under pressure. From a practical perspective, TA can aid a player, coach or sport psychologist by allowing thought processes to be identified and investigate a performer’s thoughts when faced with the pressure of a competition.

  9. Numerical investigation of the threshold intensity dependence on gas pressure in the breakdown of xenon by different laser wavelengths

    Science.gov (United States)

    Gamal, Yosr E. E.-D.; Abd El Hameid Mahmoud, Mohamed; Dawood, Nagia D. A.

    2014-07-01

    We report a theoretical analysis of the measurements that carried out to study the breakdown of xenon gas over a wide pressure range induced by laser source operating at different wavelengths. The study provided an investigation of the effect of laser wavelength as well as gas pressure on the physical processes associated with this phenomenon. To this aim a modified electron cascade model is applied. The model based on the numerical solution of the time dependent Boltzmann equation for the electron energy distribution function (EEDF) simultaneously with a set of rate equations which describe the rate of change of the formed excited states population. Comparison between the calculated and measured threshold intensities for the experimentally tested laser wavelengths and gas pressure range is obtained. Furthermore computations of the EEDF and its parameters showed the actual correlation between the gain and loss processes which determine the threshold breakdown intensity of xenon and the two experimentally tested parameters; laser wavelength and gas pressure.

  10. Panethnic Differences in Blood Pressure in Europe: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Pietro Amedeo Modesti

    Full Text Available People of Sub Saharan Africa (SSA and South Asians(SA ethnic minorities living in Europe have higher risk of stroke than native Europeans(EU. Study objective is to provide an assessment of gender specific absolute differences in office systolic(SBP and diastolic(DBP blood pressure(BP levels between SSA, SA, and EU.We performed a systematic review and meta-analysis of observational studies conducted in Europe that examined BP in non-selected adult SSA, SA and EU subjects. Medline, PubMed, Embase, Web of Science, and Scopus were searched from their inception through January 31st 2015, for relevant articles. Outcome measures were mean SBP and DBP differences between minorities and EU, using a random effects model and tested for heterogeneity. Twenty-one studies involving 9,070 SSA, 18,421 SA, and 130,380 EU were included. Compared with EU, SSA had higher values of both SBP (3.38 mmHg, 95% CI 1.28 to 5.48 mmHg; and 6.00 mmHg, 95% CI 2.22 to 9.78 in men and women respectively and DBP (3.29 mmHg, 95% CI 1.80 to 4.78; 5.35 mmHg, 95% CI 3.04 to 7.66. SA had lower SBP than EU(-4.57 mmHg, 95% CI -6.20 to -2.93; -2.97 mmHg, 95% CI -5.45 to -0.49 but similar DBP values. Meta-analysis by subgroup showed that SA originating from countries where Islam is the main religion had lower SBP and DBP values than EU. In multivariate meta-regression analyses, SBP difference between minorities and EU populations, was influenced by panethnicity and diabetes prevalence.1 The higher BP in SSA is maintained over decades, suggesting limited efficacy of prevention strategies in such group in Europe;2 The lower BP in Muslim populations suggests that yet untapped lifestyle and behavioral habits may reveal advantages towards the development of hypertension;3 The additive effect of diabetes, emphasizes the need of new strategies for the control of hypertension in groups at high prevalence of diabetes.

  11. Differences in blood pressure measurements in the forearm and upper arm of obese otherwise healthy first year medical students

    Directory of Open Access Journals (Sweden)

    Suganthi V, Navin Rajaratnam, Suzanne Maria D’cruz

    2014-07-01

    Full Text Available Background: The prevalence of obesity is increasing in Indian youth and obesity is associated with complications like systemic hypertension. Often, due to the non-availability of appropriate sized cuffs, standard cuff bladders are used to measure blood pressure in the forearms of obese young adults. Aim: To compare the upper arm arterial blood pressure measured using an appropriate cuff with the forearm arterial blood pressure measured using a standard cuff and conventional sphygmomanometry in obese otherwise healthy first year medical students. Materials and Methods: Blood pressure was measured in 27 obese otherwise healthy first year medical students after five minutes of rest using a mercury sphygmomanometer with the subjects seated and the arm and forearm at heart level, using an appropriate sized cuff for the upper arm according to American Heart Association standards and a standard cuff for the fore arm. Results: A statistically significant difference in both systolic [t-test (paired = -6.921; df = 26; sig = .000 (2- tailed] and diastolic blood pressure [t-test (paired = -8.508; df = 26; sig = .000 (2- tailed] was found, with the blood pressure readings being higher in the forearm. The correlations between upper arm and forearm systolic and diastolic blood pressure were 0.785 (p = .000 and 0.870 (p = .000. Conclusion: Both systolic and diastolic blood pressure measurements were significantly higher in the forearm. Further studies with larger sample size should be conducted to confirm that forearm blood pressure measurements using standard cuff bladders cannot be considered equal to upper arm measurements made using an appropriate sized cuff in all young obese individuals

  12. Neutron spectra at different High Flux Isotope Reactor (HFIR) pressure vessel surveillance locations

    International Nuclear Information System (INIS)

    Remec, I.; Kam, F.B.

    1993-12-01

    This project addresses the potential problem of radiation embrittlement of reactor pressure vessel (RPV) supports. Surveillance specimens irradiated at the High Flux Isotope Reactor (HFIR) at relatively low neutron flux levels (about 1.5E + 8 cm -2 .s -1 ) and low temperatures (about 50 degrees C) showed embrittlement more rapidly than expected. Commercial power reactors have similar flux levels and temperatures at the level vessel support structures. The purposes of this work are to provide the neutron fluence spectra data that are needed to evaluate previously measured mechanical property changes in the HFIR, to explain the discrepancies in neutron flux levels between the nickel dosimeters and two other dosimeters, neptunium and beryllium, and to address any questions or peculiarities of the HFIR reactor environment. The current work consists of neutron and gamma transport calculations, dosimetry measurements, and least-squares logarithmic adjustment to obtain the best estimates for the neutron spectra and the related neutron exposure parameters. The results indicate that the fission rates in neptunium-237 (Np-237) and uranium-238 (U-238) and the helium production rates in beryllium-9 (Be-9) are dominated by photo-induced reactions. The displacements per atom rate for iron (dpa/s) from gamma rays is five times higher than the dpa/s from neutrons. The neutron fluxes in key 7, position 5 do not show any significant gradient in the surveillance capsule, but key 4 and key 2 showed differences in magnitude as well as in the shape of the spectrum. The stainless steel monitor in the V-notch of the Charpy specimens of the surveillance capsules is adequate to determine the neutron flux above 1.0 MeV at the desired V-notch location. Simultaneous adjustment of neutron and gamma fluxes with the measurements has been demonstrated and should avoid future problems with photo-induced reactions

  13. Differences in selective pressure on dhps and dhfr drug resistant mutations in western Kenya

    Directory of Open Access Journals (Sweden)

    McCollum Andrea M

    2012-03-01

    pressures on various dhfr and dhps mutants relative to each other based on a theoretical model tailored to P. falciparum. The data indicate that drug selection acted differently on the resistant alleles of dhfr and dhps, as evidenced by fitness differences. Thus a combination drug therapy such as SP, by itself, does not appear to select for "multidrug"-resistant parasites in areas with high recombination rate. Conclusions The complexity of these observations emphasizes the importance of population-based studies to evaluate the effects of strong drug selection on Plasmodium falciparum populations.

  14. Blood pressure variability and risk of cardiovascular events and death in patients with hypertension and different baseline risks.

    Science.gov (United States)

    Mehlum, Maria H; Liestøl, Knut; Kjeldsen, Sverre E; Julius, Stevo; Hua, Tsushung A; Rothwell, Peter M; Mancia, Giuseppe; Parati, Gianfranco; Weber, Michael A; Berge, Eivind

    2018-01-20

    Blood pressure variability is associated with increased risk of cardiovascular events, particularly in high-risk patients. We assessed if variability was associated with increased risk of cardiovascular events and death in hypertensive patients at different risk levels. The Valsartan Antihypertensive Long-term Use Evaluation trial was a randomized controlled trial of valsartan vs. amlodipine in patients with hypertension and different risks of cardiovascular events, followed for a mean of 4.2 years. We calculated standard deviation (SD) of mean systolic blood pressure from visits from 6 months onward in patients with ≥3 visits and no events during the first 6 months. We compared the risk of cardiovascular events in the highest and lowest quintile of visit-to-visit blood pressure variability, using Cox regression. For analysis of death, variability was analysed as a continuous variable. Of 13 803 patients included, 1557 (11.3%) had a cardiovascular event and 1089 (7.9%) died. Patients in the highest quintile of SD had an increased risk of cardiovascular events [hazard ratio (HR) 2.1, 95% confidence interval (95% CI) 1.7-2.4; P blood pressure was associated with a 10% increase in the risk of death (HR 1.10, 95% CI 1.04-1.17; P = 0.002). Associations were stronger among younger patients and patients with lower systolic blood pressure, and similar between patients with different baseline risks, except for higher risk of death among patients with established cardiovascular disease. Higher visit-to-visit systolic blood pressure variability is associated with increased risk of cardiovascular events in patients with hypertension, irrespective of baseline risk of cardiovascular events. Associations were stronger in younger patients and in those with lower mean systolic blood pressure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.

  15. Attachment of MEM piezoresistive silicon pressure sensor dies using different adhesives

    Directory of Open Access Journals (Sweden)

    Jović Vesna B.

    2011-01-01

    Full Text Available This paper gives comparison and discussion of adhesives used for attachment of silicon piezoresistive pressure sensor dies. Special attention is paid on low pressure sensor dies because of their extreme sensitivity on stresses, which can arise from packaging procedure and applied materials. Commercially available adhesives “Scotch Weld 2214 Hi-Temp” from “3M Co.” and “DM2700P/H848” from “DIEMAT”, USA, were compared. First of them is aluminum filled epoxy adhesive and second is low melting temperature (LMT glass paste. Comparing test results for low pressure sensor chips we found that LMT glass (glass frit is better adhesive for this application. Applying LMT glass paste minimizes internal stresses caused by disagreement of coefficients of thermal expansions between sensor die and housing material. Also, it minimizes stresses introduced during applying external loads in the process of pressure measuring. Regarding the measurements, for the sensors installed with filled epoxy paste, resistor for compensation of temperature offset change had negative values in all cases, which means that linear temperature compensation, of sensors installed this way, would be impossible. In the sensors installed with LMT glass paste, all results, without exception, were in their common limits (values, which give the possibility of passive temperature compensation. Furthermore, LMT glass attachment can broaden temperature operating range of MEM silicon pressure sensors towards higher values, up to 120 ºC.

  16. A cost-effectiveness analysis of two different repositioning strategies for the prevention of pressure ulcers.

    Science.gov (United States)

    Marsden, Grace; Jones, Katie; Neilson, Julie; Avital, Liz; Collier, Mark; Stansby, Gerard

    2015-12-01

    To assess the cost effectiveness of two repositioning strategies and inform the 2014 National Institute for Health and Care Excellence clinical guideline recommendations on pressure ulcer prevention. Pressure ulcers are distressing events, caused when skin and underlying tissues are placed under pressure sufficient to impair blood supply. They can have a substantial impact on quality of life and have significant resource implications. Repositioning is a key prevention strategy, but can be resource intensive, leading to variation in practice. This economic analysis was conducted to identify the most cost-effective repositioning strategy for the prevention of pressure ulcers. The economic analysis took the form of a cost-utility model. The clinical inputs to the model were taken from a systematic review of clinical data. The population in the model was older people in a nursing home. The economic model was developed with members of the guideline development group and included costs borne by the UK National Health Service. Outcomes were expressed as costs and quality adjusted life years. Despite being marginally more clinically effective, alternating 2 and 4 hourly repositioning is not a cost-effective use of UK National Health Service resources (compared with 4 hourly repositioning) for this high risk group of patients at a cost-effectiveness threshold of £20,000 per quality adjusted life years. These results were used to inform the clinical guideline recommendations for those who are at high risk of developing pressure ulcers. © 2015 John Wiley & Sons Ltd.

  17. Numerical simulation and experimental investigation of Ti-6Al-4V melted by CW fiber laser at different pressures

    Science.gov (United States)

    Tabassum, Aasma; Zhou, Jie; Han, Bing; Ni, Xiao-wu; Sardar, Maryam

    2017-07-01

    The interaction of continuous wave (CW) fiber laser with Ti-6Al-4V alloy is investigated numerically and experimentally at different laser fluence values and ambient pressures of N2 atmosphere to determine the melting time threshold of Ti-6Al-4V alloy. A 2D-axisymmetric numerical model considering heat transfer and laminar flow is established to describe the melting process. The simulation results indicate that material melts earlier at lower pressure (8.0 Pa) than at higher pressure (8.8×104 Pa) in several milliseconds with the same laser fluence. The experimental results demonstrate that the melting time threshold at high laser fluence (above 1.89×108 W/m2) is shorter for lower pressure (vacuum), which is consistent with the simulation. While the melting time threshold at low laser fluence (below 1.89×108 W/m2) is shorter for higher pressure. The possible aspects which can affect the melting process include the increased heat loss induced by the heat conduction between the metal surface and the ambient gas with the increased pressure, and the absorption variation of the coarse surface resulted from the chemical reaction.

  18. Skin perfusion pressure measured by isotope washout in legs with arterial occlusive disease. Evaluation of different tracers, comparison to segmental systolic pressure, angiography and transcutaneous oxygen tension and variations during changes in systemic blood pressure

    DEFF Research Database (Denmark)

    Holstein, P; Trap-Jensen, J; Bagger, H

    1983-01-01

    in legs with arterial occlusions at two levels or more; (4) In 47 legs with AOD, the SPP on the calf or on the thigh was compared with transcutaneously measured pO2. The two different methods correlated statistically significant, but the scatter was great; (5) During induced variations in systemic blood...... that 99Tcm is as suitable as the 131I- -labelled tracers in estimating the SPP. The SPP is significantly correlated to skin blood flow, to systolic blood pressure, to tc pO2 and to angiographic findings. Correction of SPP for systemic blood pressure changes can be made in proportion with the measured...... variations in systemic mean blood pressure, but only for groups of patients....

  19. INFLUENCE OF CHRONOTHERAPY WITH DIFFERENT ANTIHYPERTENSIVE DRUGS ON CIRCADIAN BLOOD PRESSURE PATTERN

    Directory of Open Access Journals (Sweden)

    V. M. Gorbunov

    2016-01-01

    Full Text Available Aim. To determine the value of different blood pressure (BP measurement methods for arterial hypertension (HT chronotherapy efficacy assessment. Material and methods. Two similar open, randomized, cross-over studies (morning vs evening intake were carried out. Duration of the initial wash-out period was 2 weeks; duration of both treatment courses — 3 weeks; the interval between courses — 1 week. Only patients with stable HT (mean day-time BP>135/85 mm Hg were included. Ambulatory BP monitoring (ABPM was carried out prior to treatment and at the end of both treatment courses. The patients performed home BP monitoring (HBPM throughout the study. Pharmacokinetics of verapamil (n=14, mean daily dose — 240.0±16.3 mg was studied to assess compliance with verapamil therapy. In ramipril trial (n=30 its mean daily dose was 8.9±0.7 mg. The following main ABPM variables were analyzed: ABPM means and variability, maximal and minimal values, nocturnal BP fall, parameters of Fourier transformation and smoothness index. The morning and evening BP means and morning BP surge (morning – evening BP were assessed by HBPM. Student’s t-value and Mahalanobis distance were used to evaluate individual value of each variable (“morning” vs “evening” effect. This analysis was first done separately for each trial. After that, combined data were analyzed. Results. Overall antihypertensive effect was more intense with morning ramipril (p<0.05 intake and evening verapamil intake. The t-values ranged 2.2-2.3 for nocturnal BP fall; 2.0-2.1 for night-time BP variability; 3.8-4.3 for morning BP surge. The t-values of office and 24-hour BP were low (0.2-1.7. Conclusion. Morning BP surge based on HBPM is a good instrument for chronotherapy effect assessment. Evening administration of antihypertensive drugs causes nocturnal BP fall shift towards “dipper” status.

  20. Persuader Sex Differences and Peer Pressure Effects on Attitudes Toward Drug Abuse.

    Science.gov (United States)

    Stone, Christopher I.; Shute, Robert E.

    This experiment was performed to assess the effects of the experimental confederates' sex and contrived group peer pressure on the drug attitudes of male college students. Subjects were exposed to all male or all female groups of experimental confederates (persuaders) who expressed either extremely pro-drug or anti-drug sentiments in a guided…

  1. Composition and crystallinity of silicon nanoparticles synthesised by hot wire thermal catalytic pyrolysis at different pressures

    CSIR Research Space (South Africa)

    Scriba, MR

    2009-04-01

    Full Text Available mbar, at a flow rate of 50 sccm, using a tungsten filament at temperatures of 1900 °C and 1800 °C respectively. As determined by transmission electron microscopy and X-ray diffraction, the particles produced at lower pressure have sizes around 10 nm...

  2. Burst pressure of phaseguide structures of different heights in all-polymer microfluidic channels

    DEFF Research Database (Denmark)

    Garbarino, Francesca; Kistrup, Kasper; Rizzi, Giovanni

    2017-01-01

    We present an experimental investigation of the burst/overflow pressure of water and a representative surfactant-containing buffer in microfluidic channels with phaseguide structures oriented at an angle of 90° to the channel length as a function of their height, . The all-polymer chips were fabr...

  3. Evaluation of Intracranial Pressure in Different Body Postures and Disease Entities

    DEFF Research Database (Denmark)

    Andresen, Morten; Hadi, Amer; Juhler, Marianne

    2016-01-01

    We currently do not have sufficient knowledge regarding appropriate boundaries between "normal" and "abnormal" intracranial pressure (ICP) in humans. Our objective in this study was to quantify the effects of postural changes on ICP in normal and ill subjects. As a model for normal patients, we...

  4. Rayleigh-Brillouin scattering profiles of air at different temperatures and pressures

    NARCIS (Netherlands)

    Gu, Z.; Witschas, B.; van der Water, W.; Ubachs, W.M.G.

    2013-01-01

    Rayleigh-Brillouin (RB) scattering profiles for air have been recorded for the temperature range from 255 to 340 K and the pressure range from 640 to 3300 mbar, covering the conditions relevant for the Earth's atmosphere and for planned atmospheric light detection and ranging (LIDAR) missions. The

  5. Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry

    OpenAIRE

    Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

    2016-01-01

    Objective: Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Methods: Twenty automotive workers were individually fitted out with three differe...

  6. Isometric Back Exercise Has Different Effect on Pressure Pain Thresholds in Healthy Men and Women

    DEFF Research Database (Denmark)

    Gajsar, Hannah; Titze, Christina; Hasenbring, Monika Ilona

    2017-01-01

    inhibitory mechanisms. So far the results on EIH in patients with low back pain (LBP) are equivocal and no studies have investigated an EIH paradigm targeting the lower back in order to assess EIH in patients with LBP. Thus, the aim of this pilot study was to assess pressure pain sensitivity at local...... and remote assessment sites, before and after an isometric back exercise in healthy women and men. METHODS: In a pre-posttest design, pressure pain thresholds (PPT) were assessed at the lower back, biceps femoris muscle, and hand in 29 healthy subjects (17 women) before and after 120 seconds of the isometric......OBJECTIVE: Isometric exercises produce an acute decrease in the pain sensitivity, known as exercise-induced hypoalgesia (EIH). Existing EIH paradigms use exercises at the extremities with more pronounced EIH at local compared to remote body sites, indicating local inhibition in addition to central...

  7. Titration effectiveness of two autoadjustable continuous positive airway pressure devices driven by different algorithms in patients with obstructive sleep apnoea.

    Science.gov (United States)

    Damiani, Mario Francesco; Quaranta, Vitaliano Nicola; Tedeschi, Ersilia; Drigo, Riccardo; Ranieri, Teresa; Carratù, Pierluigi; Resta, Onofrio

    2013-08-01

    Nocturnal application of continuous positive airway pressure (CPAP) is the standard treatment for patients with obstructive sleep apnoea (OSA). Determination of the therapeutic pressure (CPAP titration) is usually performed by a technician in the sleep laboratory during attended polysomnography. One possible alternative to manual titration is automated titration. Indeed, during the last 15 years, devices have been developed that deliver autoadjustable CPAP (A-CPAP). The aim of the present study was to compare the titration effectiveness of two A-CPAP devices using different flow-based algorithms in patients with OSA. This is a randomized study; 79 subjects underwent two consecutive unattended home A-CPAP titration nights with two different devices (Autoset Resmed; Remstar Auto Respironics); during the third and the fourth night, patients underwent portable monitoring in the sleep laboratory during fixed CPAP at the A-CPAP recommended pressure. Bland Altman plots showed good agreement between the recommended median and maximal pressure levels obtained with the two devices. A significant improvement was observed in all the sleep parameters by both A-CPAP machines to a similar degree. It was observed that the two A-CPAP devices using different algorithms are equally effective in initial titration of CPAP. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

  8. Effects of nanoparticle types and size on boiling feat transfer performance under different pressures

    Science.gov (United States)

    Yao, Shouguang; Huang, Xiaogan; Song, Yindong; Shen, Yan; Zhang, Shili

    2018-02-01

    The experimental study on the boiling heat transfer performance and visualization of Al2O3-H2O, SiO2-H2O and Al2O3-SiO2-H2O nanofluids with 0.01% mass concentration were carried out. Alumina and silica nanoparticles with average particle diameters of 30 nm and 50 nm were selected. Al2O3-SiO2-H2O was the mixed aqueous nanofluids with a mass ratio of Al2O3 to SiO2 of 1: 1. The results show that the effect of particle size on the boiling heat transfer performance is small. For nanofluids with a particle size of 30 nm, the boiling heat transfer performance of Al2O3-H2O nanofluids is better than that of Al2O3-SiO2-H2O and SiO2-H2O nanofluids under the working pressure of 101 kPa. The critical heat fluxes increased by 7.9% and 22.1% respectively, and the maximum heat transfer coefficients increased by 18.3% and 32.6% respectively. The critical heat flux and the maximum heat transfer coefficient are 162.1 W/cm2 and 7.01W/(m2.K). The working pressure has an important effect on the boiling heat transfer performance of nanofluids. Compared with the boiling heat transfer performance under high pressure conditions, the boiling heat transfer performance of nanofluids is better under low pressure.

  9. Gender differences in the relationship between resting heart rate variability and 24-hour blood pressure variability.

    Science.gov (United States)

    Thayer, Julian F; Sollers, John J; Friedman, Bruce H; Koenig, Julian

    2016-01-01

    The study explored the relationship between time- and frequency-domain indices of cardiac autonomic control and 24 h blood pressure variability (BPV) in a sample of healthy men and women. Vagally mediated cardiac control was inversely related to 24 h BPV, and measures of cardiac autonomic control were better predictors of systolic BPV in men and better predictors of diastolic BPV in women. These findings may help researchers to understand the disparity in cardiovascular disease morbidity and mortality between men and women.

  10. EFFECT OF DIFFERENT COMPACTION PRESSURE AND DIFFERENT SINTERING ROUTE ON K0.5NA0.5NBO₃ PHYSICAL AND DIELECTRIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    Nor Fatin Khairah Bahanurddin

    2016-07-01

    Full Text Available Alkaline niobate known as K0.5Na0.5NbO3 (KNN, a lead-free piezoelectric ceramic was synthesized via a solid state reaction method. The samples were compacted at different pressures (100, 200, 300 and 400 MPa and sintered using two different techniques (conventional furnace and hot isostatic pressing (HIP. The effect of compaction pressure and sintering technique on physical and dielectric properties was studied. The optimum compaction pressure (300 MPa and sintering via HIP (at 1080 °C for 30 min increased the density and grain size ( range 30 - 300 nm and improved its dielectric properties. Therefore, the combination of suitable compaction pressure and sintering technique has produced larger grain size and higher density of KNN which resulted in outstanding dielectric properties. At room temperature, excellent values of ε r (5517.35 and tan δ (0.954, recorded at 1 MHz were measured for the KNN300HIP sample with highest density (4.4885 g/cm³.

  11. Combustion characteristics and kinetic analysis of pulverized coal under different pressure grades

    Directory of Open Access Journals (Sweden)

    Qiwei ZUO

    2016-02-01

    Full Text Available By using thermo gravimetric balance, experimental research on combustion characteristics and dynamics parameters of the typical coal injection from some domestic steelworks are conducted with non-isothermal method. The combustion characteristic parameters of the sample pulverized coal such as ignition temperature, peak temperature at maximum weight loss rate, burnout temperature, general burn exponent(S, and maximum combustion rate are studied under pressure grades of 0.1, 1.1, 2.1, 3.1 and 4.1 MPa, the activation energy (E and pre-exponential factor in the combustion process are calculated. The results show that when the pressure increases from 0.1 to 4.1 MPa, ignition temperature decreases by 85.7 K at most, peak temperature at maximum weight loss rate decreases by 249.3 K at most, burnout temperature decreases by 375 K at most, maximum weight loss rate increases by 10 times, and S increases by 33.6 times at most. It is also shown that there exists a kinetic complementation between E and ln A from the view point of dynamics, and the critical pressure of pulverized coal reaction control requirement and combustion mode transform is 3.1 MPa for the pulverized coal.

  12. Effect of high hydrostatic pressure on the supramolecular structure of corn starch with different amylose contents.

    Science.gov (United States)

    Yang, Zhi; Swedlund, Peter; Hemar, Yacine; Mo, Guang; Wei, Yanru; Li, Zhihong; Wu, Zhonghua

    2016-04-01

    Corn starches with amylose contents ranging from 0 to 80% were suspended in 60 wt% water or ethanol and subjected to high hydrostatic pressure (HHP) up to 600 MPa. The impact of HHP treatment on the granule morphology, lamellae structures, and crystalline characteristics were examined with a combination of SAXS, WAXS and optical microscopy. All starch dispersed in water showed a decrease in area of the lamellar peak in the SAXS data at q∼0.6 nm(-1). The lamellae thickness (d) increased for pressurized waxy, normal, and Gelose80 corn starches, suggesting water is forced into starch lamellae during HHP. However, for Gelose50 corn starch, the d remained constant over the whole pressure range and light microscopy showed no obvious granule swelling. WAXS studies demonstrated that HHP partially converted A-type starches (waxy and normal corn) to starches with a faint B-type pattern while starches with a B+V-type pattern (Gelose50 and Gelose80), were not affected by HHP. All corn starches suspended in ethanol showed no detectable changes in either granule morphology, or the fractal, the lamellae, and the crystalline structures. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Experimental study and theoretical interpretation of saturation effect on ultrasonic velocity in tight sandstones under different pressure conditions

    Science.gov (United States)

    Li, Dongqing; Wei, Jianxin; Di, Bangrang; Ding, Pinbo; Huang, Shiqi; Shuai, Da

    2018-03-01

    Understanding the influence of lithology, porosity, permeability, pore structure, fluid content and fluid distribution on the elastic wave properties of porous rocks is of great significance for seismic exploration. However, unlike conventional sandstones, the petrophysical characteristics of tight sandstones are more complex and less understood. To address this problem, we measured ultrasonic velocity in partially saturated tight sandstones under different effective pressures. A new model is proposed, combining the Mavko-Jizba-Gurevich relations and the White model. The proposed model can satisfactorily simulate and explain the saturation dependence and pressure dependence of velocity in tight sandstones. Under low effective pressure, the relationship of P-wave velocity to saturation is pre-dominantly attributed to local (pore scale) fluid flow and inhomogeneous pore-fluid distribution (large scale). At higher effective pressure, local fluid flow gradually decreases, and P-wave velocity gradually shifts from uniform saturation towards patchy saturation. We also find that shear modulus is more sensitive to saturation at low effective pressures. The new model includes wetting ratio, an adjustable parameter that is closely related to the relationship between shear modulus and saturation.

  14. Pressure produced on the residual maxillary alveolar ridge by different impression materials and tray design: an in vivo study.

    Science.gov (United States)

    Reddy, Subash M; Mohan, Chenthil Arun; Vijitha, D; Balasubramanian, R; Satish, A; Kumar, Mahendira

    2013-12-01

    Increased ridge resorption may occur due to inappropriate pressure applied during final impression making phase of complete denture fabrication. This study was done to evaluate the pressure applied on the residual ridge while making impressions with two tray designs (with and without spacer) using, zinc oxide eugenol and light body polyvinyl siloxane impression material. Five edentulous subjects were randomly selected. For each of the five subjects four maxillary final impressions were made and were labelled as, Group A-Impression made with tray without spacer using zinc oxide eugenol impression, Group B-Impression made with tray with spacer using zinc oxide eugenol impression material, Group C-Impression made with tray without spacer using light body polyvinyl siloxane impression material, Group D-Impression made with tray with spacer using light body polyvinyl siloxane impression material. During the impression procedure a closed hydraulic system was used to remotely measure the pressures produced in three areas. The pressure produced were calibrated according to the micro strain record. Statistical comparisons of readings were done using t test and ANOVA. The acquired data revealed that ZOE produced an average pressures value of 26.534 and 72.05 microstrain, while light body PVS produced 11.430 and 37.584 microstrain value with and without spacer respectively. Significantly high values were recorded on the vault of the palate when using trays without spacer. The use of light body polyvinyl siloxane and zinc oxide eugenol impression material showed insignificant difference. Within the limitations of this study, tray design has a significantly effected on the pressures produced, while the impression materials does not have any significant difference.

  15. Ethnic differences in blood pressure in young men living in similar environment: a study of international adoptees in Sweden.

    Science.gov (United States)

    Silventoinen, Karri; Sundström, Johan; Tynelius, Per; Eriksson, Johan; Rasmussen, Finn

    2010-07-01

    To analyze differences in blood pressure in young men with different ethnic backgrounds but living in similar environment. We utilized information on virtually the total Swedish male population born between 1951 and 1987 including 5388 international adoptees, 8834 Swedish adoptees and 1 469 196 Swedish nonadoptees. Systolic blood pressure (SBP), height and weight were measured during conscription examination at the average age of 18.2 years. SBP was lower in international adoptees than in native-born Swedes regardless of the geographic area of origin of the adoptees. BMI and height partly explained this difference, but additional adjustment for childhood social position only slightly modified the results. The largest difference was observed in adoptees from the Indian subcontinent when compared with native-born Swedes (-5.21 95% confidence intervals -6.16 to -4.27 when adjusted for height, BMI and childhood social position). Slightly lower SBP was also observed in Swedish adoptees when compared with Swedish nonadoptees. The association between BMI and SBP did not differ between international adoptees and native-born Swedes. Our results suggest that international adoptees are not at higher risk for elevated blood pressure in young adulthood than native-born Swedes. Non-white genetic heritage or environmental exposures during pregnancy or in early life specific for adopted children may be associated with lower risk of hypertension.

  16. [ProSeal™laryngeal mask in normal weight and obese patients : oxygenation under pressure-controlled ventilation and different end-expiratory pressures].

    Science.gov (United States)

    Goldmann, K; Gerlach, M; Bornträger, C

    2011-10-01

    Most of the data on combining pressure-controlled ventilation (PCV) with positive end-expiratory pressure (PEEP) come from studies with an endotracheal tube (ETT) whereas data on utilization of PEEP with a laryngeal mask airway (LMA) are limited. The LMA-ProSeal® (PLMA) forms a more effective seal of the airway than the LMA-Classic™ (CLMA). The application of PEEP when PCV is used with the PLMA could have an impact on oxygenation in adult patients. For this study 148 patients with an mean age of 44 years (range18-65 years) and mean weight of 86 kg (range 49-120 kg) were recruited in 2 groups: group N ((Normal)): body-mass index (BMI) cmH(2)O, 5 cmH(2)O or 8 cmH(2)O PEEP. An arterial blood gas sample was taken 50 min after induction of anesthesia under an inspiratory oxygen fraction (F(I)O(2)) of 0.3. In the first part partial oxygen pressure (p(a)O(2)) under 0 cmH(2)O was compared with p(a)O(2) under 5 cmH(2)O and in the second part p(a)O(2) under 5 cmH(2)O was compared with p(a)O(2) under 8 cmH(2)O. A significant difference was set as pcmH(2)O. Both findings are in contrast to findings of studies using an ETT which suggests that higher pressures (40 cmH(2)O) are needed for recruitment of collapsed alveoli and higher PEEP (10 cmH(2)O) is needed to produce a clinically significant improvement in oxygenation in obese patients. The results of this study support data showing that the consequences of bronchopulmonary airway reactions known to occur with an ETT are less pronounced or absent when an LMA is used.

  17. Effects of different computer typing speeds on acceleration and peak contact pressure of the fingertips during computer typing.

    Science.gov (United States)

    Yoo, Won-Gyu

    2015-01-01

    [Purpose] This study showed the effects of different computer typing speeds on acceleration and peak contact pressure of the fingertips during computer typing. [Subjects] Twenty-one male computer workers voluntarily consented to participate in this study. They consisted of 7 workers who could type 200-300 characteristics/minute, 7 workers who could type 300-400 characteristics/minute, and 7 workers who could type 400-500 chracteristics/minute. [Methods] This study was used to measure the acceleration and peak contact pressure of the fingertips for different typing speed groups using an accelerometer and CONFORMat system. [Results] The fingertip contact pressure was increased in the high typing speed group compared with the low and medium typing speed groups. The fingertip acceleration was increased in the high typing speed group compared with the low and medium typing speed groups. [Conclusion] The results of the present study indicate that a fast typing speed cause continuous pressure stress to be applied to the fingers, thereby creating pain in the fingers.

  18. Foot pressure analysis of adults with flat and normal feet at different gait speeds on an ascending slope.

    Science.gov (United States)

    Kim, Myoung-Kwon

    2015-12-01

    [Purpose] This study was conducted to determine the difference in foot pressures between flat and normal feet at different gait speeds on an ascending slope. [Subjects] This study enrolled 30 adults with normal (n=15) and flat feet (n=15), with ages from 21 to 30 years old, who had no history of neurological disorders or gait problems. A treadmill was used for the analysis of kinematic features during gait, using a slope of 10%, and gait velocities of slow, normal, and fast. [Methods] A foot pressure analyzer was used to measure changes in foot pressure. [Results] Compared to the normal subjects, the foot pressure of the flatfoot subjects showed a significant increase in the 2-3rd metatarsal region with increasing gait speed, whereas there were significant decreases in the 1st toe and 1st metatarsal regions with increasing gait speed. [Conclusion] The body weight of adults with flatfoot was concentrated on the 2-3rd metatarsal region during the stance phase and increased with walking speed on the ascending slope due to weakening of function of the medial longitudinal arch.

  19. The roles of different salts and a novel osmotic pressure control strategy for improvement of DHA production by Schizochytrium sp.

    Science.gov (United States)

    Hu, Xue-Chao; Ren, Lu-Jing; Chen, Sheng-Lan; Zhang, Li; Ji, Xiao-Jun; Huang, He

    2015-11-01

    The effects of different osmotic pressure, changed by six salts (NaCl, Na2SO4, (NH4)2SO4, KH2PO4 and MSG), on cell growth and DHA synthesis by Schizochytrium sp. were investigated. Six optimal mediums were obtained to study different osmotic pressure combinations at cell growth stage and DHA synthesis stage. Results showed that cultivated cell in higher osmotic pressure condition and fermented in lower osmotic pressure condition was benefit to enhance DHA synthesis. Combination 17-6 could get the maximum cell dry weight of 56.95 g/L and the highest DHA percentage in total fatty acids of 55.21%, while combination 17-B could get the highest lipid yield of 33.47 g/L with 42.10% DHA in total fatty acids. This was the first report about the enhancement of DHA production by osmotic regulation and this work provided two novel osmotic control processes for high lipid yield and high DHA percentage in total fatty acids.

  20. Measurement of blood pressure for the diagnosis and management of hypertension in different ethnic groups: one size fits all.

    Science.gov (United States)

    Gill, Paramjit; Haque, M Sayeed; Martin, Una; Mant, Jonathan; Mohammed, Mohammed A; Heer, Gurdip; Johal, Amanpreet; Kaur, Ramandeep; Schwartz, Claire; Wood, Sally; Greenfield, Sheila M; McManus, Richard J

    2017-02-08

    Hypertension is a major risk factor for cardiovascular disease and prevalence varies by ethnic group. The diagnosis and management of blood pressure are informed by guidelines largely based on data from white populations. This study addressed whether accuracy of blood pressure measurement in terms of diagnosis of hypertension varies by ethnicity by comparing two measurement modalities (clinic blood pressure and home monitoring) with a reference standard of ambulatory BP monitoring in three ethnic groups. Cross-sectional population study (June 2010 - December 2012) with patients (40-75 years) of white British, South Asian and African Caribbean background with and without a previous diagnosis of hypertension recruited from 28 primary care practices. The study compared the test performance of clinic BP (using various protocols) and home-monitoring (1 week) with a reference standard of mean daytime ambulatory measurements using a threshold of 140/90 mmHg for clinic and 135/85 mmHg for out of office measurement. A total of 551 participants had complete data of whom 246 were white British, 147 South Asian and 158 African Caribbean. No consistent difference in accuracy of methods of blood pressure measurement was observed between ethnic groups with or without a prior diagnosis of hypertension: for people without hypertension, clinic measurement using three different methodologies had high specificity (75-97%) but variable sensitivity (33-65%) whereas home monitoring had sensitivity of 68-88% and specificity of 64-80%. For people with hypertension, detection of a raised blood pressure using clinic measurements had sensitivities of 34-69% with specificity of 73-92% and home monitoring had sensitivity (81-88%) and specificity (55-65%). For people without hypertension, ABPM remains the choice for diagnosing hypertension compared to the other modes of BP measurement regardless of ethnicity. Differences in accuracy of home monitoring and clinic monitoring (higher sensitivity

  1. Chronic fatigue syndrome and idiopathic intracranial hypertension: Different manifestations of the same disorder of intracranial pressure?

    Science.gov (United States)

    Higgins, J Nicholas P; Pickard, John D; Lever, Andrew M L

    2017-08-01

    Though not discussed in the medical literature or considered in clinical practice, there are similarities between chronic fatigue syndrome and idiopathic intracranial hypertension (IIH) which ought to encourage exploration of a link between them. The cardinal symptoms of each - fatigue and headache - are common in the other and their multiple other symptoms are frequently seen in both. The single discriminating factor is raised intracranial pressure, evidenced in IIH usually by the sign of papilloedema, regarded as responsible for the visual symptoms which can lead to blindness. Some patients with IIH, however, do not have papilloedema and these patients may be clinically indistinguishable from patients with chronic fatigue syndrome. Yet IIH is rare, IIH without papilloedema (IIHWOP) seems rarer still, while chronic fatigue syndrome is common. So are the clinical parallels spurious or is there a way to reconcile these conflicting observations? We suggest that it is a quirk of clinical measurement that has created this discrepancy. Specifically, that the criteria put in place to define IIH have led to a failure to appreciate the existence, clinical significance or numerical importance of patients with lower level disturbances of intracranial pressure. We argue that this has led to a grossly implausible distortion of the epidemiology of IIH such that the milder form of the illness (IIHWOP) is seen as less common than the more severe and that this would be resolved by recognising a connection with chronic fatigue syndrome. We hypothesise, therefore, that IIH, IIHWOP, lesser forms of IIH and an undetermined proportion of chronic fatigue cases are all manifestations of the same disorder of intracranial pressure across a spectrum of disease severity, in which this subset of chronic fatigue syndrome would represent the most common and least severe and IIH the least common and most extreme. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Iron exclusion in rice genotypes as affected by different vapor pressure deficit conditions

    Directory of Open Access Journals (Sweden)

    Ram Kumar Shrestha

    2015-08-01

    Full Text Available Root iron (Fe exclusion capacity of four lowland rice genotypes were evaluated in increasing rate of Fe2+ stresses (0, 500, 1000 and 1500 mg/L in growing medium under the conditions of low and high vapor pressure deficit. Rice root excluded significantly higher amount of iron under dry atmospheric condition (655 mg Fe/g root dry matter than moist atmospheric condition (118 mg Fe/g root dry matter. But their iron exclusion capacity reduced when they were gradually exposed to the higher levels of Fe stress. Tolerant genotype such as TOX3107 excluded more iron when they were exposed to dry atmospheric condition.

  3. Comparison of Diesel Spray Combustion in Different High-temperature, High-pressure Facilities

    DEFF Research Database (Denmark)

    Pickett, Lyle M.; Genzale, Caroline L.; Bruneaux, Gilles

    2010-01-01

    results from comparative studies using constant-volume vessels at Sandia National Laboratories and IFP. Targeting the same ambient gas conditions (900 K, 60 bar, 22.8 kg/m 3 , 15% oxygen) and using the same injector specifications (common rail, 1500 bar, KS 1.5/86 nozzle, 0.090 mm orifice diameter, n...... boundary conditions at these unique facilities. Performing experiments at the same high-temperature, high-pressure operating conditions is an objective of the Engine Combustion Network (http://www.ca.sandia.gov/ECN/), which seeks to leverage the research capabilities and advanced diagnostics of all...

  4. THE ROLE OF DIFFERENT RHEOLOGICAL MODELS IN ACCURACY OF PRESSURE LOSS PREDICTION

    Directory of Open Access Journals (Sweden)

    Katarina Simon

    2004-12-01

    Full Text Available Hydraulics play an important function in many oil field operations including drilling, completion, fracturing, acidizing, workover and production. The standard API methods for drilling fluid hydraulics assume either power law or Bingham plastic rheological model. These models and corresponding hydraulic calculations do provide a simple way for fair estimates of hydraulics for conventional vertical wells using simple drilling fluids, such as bentonite fluids. However, nowdays with many wells drilled deep, slim or horizontal using complex muds with unusual behaviour (such as tested MMH mud, it is necessary to use appropriate rheological model for mathematical modelling of fluid behaviour. Oil and gas reservoirs in Croatia have been under production for quite a while and the probability to discover new deposits of hydrocarbons is rather small. Therefore attempts have been made to maintain the gas and oil exploitation at the present level. One of possible ways to meet this target is re-entry wells drilling. The diameter of such wells in reservoir is smaller than 0,1524 m (6 in. Accurate modelling of annular pressure losses becomes therefore an important issue, particularly in cases where a small safety margin exists between optimal drilling parameters and wellbore stability, what is the case in re-entry wells. The objective of the paper is to show the influence of well geometry and accuracy of fluid rheological properties modelling to the distribution of pressure losses in a slimhole well.

  5. The minimum data set pressure ulcer indicator: does it reflect differences in care processes related to pressure ulcer prevention and treatment in nursing homes?

    Science.gov (United States)

    Bates-Jensen, Barbara M; Cadogan, Mary; Osterweil, Dan; Levy-Storms, Lené; Jorge, Jennifer; Al-Samarrai, Nahla; Grbic, Valena; Schnelle, John F

    2003-09-01

    To determine whether nursing homes (NHs) that score in the extreme quartiles of pressure ulcer (PU) prevalence as reported on the Minimum Data Set (MDS) PU quality indicator provide different PU care. Descriptive, cohort. Sixteen NHs. Three hundred twenty-nine NH residents at risk for PU development as determined by the PU Resident Assessment Protocol of the MDS. : Sixteen care process quality indicators (10 specific to PU care processes, five related to nutrition, and one related to incontinence management) were scored using medical record data, direct human observation, interviews, and data from wireless thigh movement monitors. There were no differences between homes with low- and high-PU prevalence rates reported on the MDS PU quality indicator on most care processes. NHs with high PU prevalence rates used pressure-reduction surfaces more frequently and were better at documentation of four wound characteristics when PUs were present. No measure of PU care processes was better in low-PU NHs. Neither low- nor high-PU prevalence NHs routinely repositioned residents every 2 hours, even though 2-hour repositioning was documented in the medical record for nearly all residents. The assumption that homes with fewer PUs and thus low PU prevalence according to the MDS PU quality indicator are providing better PU care was not supported in this sample. NHs that scored low on the MDS PU quality indicator did not provide significantly better care than NHs that scored high. All NHs could improve PU prevention, as evidenced by the poor performance on prevention care processes by low- and high-PU NHs. The MDS PU quality indicator is not a useful measure of the quality of PU care in NHs and can be misleading if not presented with an explanation of the meaning of the indicator.

  6. Effect of prenatal exposure to different salt concentration on the third month's weight and blood pressure in wistar rat

    International Nuclear Information System (INIS)

    Fereidoun, H.

    2009-01-01

    In utero alterations in fluid and electrolyte endocrine systems may result in permanent effects on offspring. A low sodium intake during prenatal life jeopardizes growth in young rats, prenatal high-salt diet in Sprague-Dawley rats caused an increase in MAP at postnatal day 30. The objective of this study was to determine the effect of prenatal exposure to different salt concentrations on the third month's weight and blood pressure in Wistar rat. This study was performed at the Department of Physiology, Isfahan University of Medical Science, Isfahan, Iran, over a period from 1998 to 2003. Six groups of rat, 1 male and 5 female in each group were exposed to 0.5, 1, 1.4, 1.6, 1.8 and 2 percent of salt concentrations during pre-pregnancy, pregnancy and lactation period, another test group consumed distilled water and control group used Isfahan tap water, other living conditions for all groups were similar. Exposure to different salt concentrations on the third month's weight and blood pressure was evaluated. Prenatal exposure to 0.5 and 1% salt concentrations gives birth to more alive and healthy infants, and third month's weight increased significantly, but blood pressure was not influenced significantly. Salt concentrations higher than 1% increased the maternal and infant mortality rate and blood pressure significantly, but some concentrations decreased third month's weight significantly. Level of dietary salt during intrauterine development can influence on the number of alive and healthy infants, birth weight, third month' weight and blood pressure significantly. There is no need to introduce a salt restricted diet in prenatal care, a balanced diet in sodium during pregnancy is recommended, high salt diet creates harmful effect. (author)

  7. The elastic constants and anisotropy of superconducting MgCNi3 and CdCNi3 under different pressure

    KAUST Repository

    Feng, Huifang

    2013-11-23

    The second-order elastic constants (SOECs) and third-order elastic constants (TOECs) of MgCNi3 and CdCNi3 are presented by using first-principles methods combined with homogeneous deformation theory. The Voigt-Reuss-Hill (VRH) approximation are used to calculate the bulk modulus B, shear modulus G, averaged Young\\'s modulus E and Poisson\\'s ratio ν for polycrystals and these effective modulus are consistent with the experiments. The SOECs under different pressure of MgCNi3 and CdCNi3 are also obtained based on the TOECs. Furthermore, the Zener anisotropy factor, Chung-Buessem anisotropy index, and the universal anisotropy index are used to describe the anisotropy of MgCNi3 and CdCNi3. The anisotropy of Young\\'s modulus of single-crystal under different pressure is also presented. © 2013 Springer Science+Business Media New York.

  8. Effects of different computer typing speeds on acceleration and peak contact pressure of the fingertips during computer typing

    OpenAIRE

    Yoo, Won-gyu

    2015-01-01

    [Purpose] This study showed the effects of different computer typing speeds on acceleration and peak contact pressure of the fingertips during computer typing. [Subjects] Twenty-one male computer workers voluntarily consented to participate in this study. They consisted of 7 workers who could type 200?300 characteristics/minute, 7 workers who could type 300?400 characteristics/minute, and 7 workers who could type 400?500 chracteristics/minute. [Methods] This study was used to measure the acce...

  9. Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

    International Nuclear Information System (INIS)

    Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T.

    1994-10-01

    Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of uranium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed

  10. Performance characteristics of seven bilevel mechanical ventilators in pressure-support mode with different cycling criteria: a comparative bench study.

    Science.gov (United States)

    Chen, Yuqing; Cheng, Kewen; Zhou, Xin

    2015-01-26

    Pressure support ventilation from a bilevel device is a standard technique for non-invasive home ventilation. A bench study was designed to compare the performance and patient-ventilator synchronization of 7 bilevel ventilators, in the presence of system leaks. Ventilators were connected to a Hans Rudolph Series 1101 lung simulator (compliance, 50 mL/cmH2O; expiratory resistance, 20 cmH2O/L/s; respiratory rate, 15 breaths/min; inspiratory time, 1.0 s). All ventilators were set at 15 cmH2O pressure support and 5 cmH2O positive end-expiratory pressure. Tests were conducted at 2 system leaks (12-15 and 25-28 L/min). The performance characteristics and patient-ventilator asynchrony were assessed, including flow, airway pressure, time, and workload. The Breas Vivo30 could not synchronize with the simulator (frequent auto-triggering) at a leak of 25-28 L/min, but provided stable assisted ventilation when the leak was 12-15 L/min. Missed efforts and back-up ventilation occurred for the Weinmann VENTImotion and Airox Smartair Plus, requiring adjustment of trigger effort. All ventilators had a short trigger delay time (ventilators, possibly due to software algorithm differences. Adjusting the cycling criteria settings can alter the shape of the inspiratory phase and peak expiratory flow, and improve patient-ventilator synchrony.

  11. Similar pressures, different contexts: public attitudes toward government intervention for health care in 21 nations.

    Science.gov (United States)

    Kikuzawa, Saeko; Olafsdottir, Sigrun; Pescosolido, Bernice A

    2008-12-01

    Health care systems worldwide are experiencing similar pressures such as rising cost, aging populations, and increased burden of disease. While policy makers in all countries face these challenges, their responses must consider local pressures, particularly the implicit social contract between the state, medicine, and insurers. We argue that public attitudes provide a window into the social context in which policy decisions are embedded. Using data from the International Social Survey Programme (ISSP), we compare public attitudes toward government involvement in health care in 21 countries, testing the associations between various national-level variables (e.g., health care expenditures, aging of population, health care traditions) and public opinions. Specifically, we posit four national-level hypotheses ("health care traditions," "expenditure crisis," "demographic crisis," "changing disease profile crisis"), one individual-level hypothesis ("individual vulnerability"), and two cross-level hypotheses ("cultural socialization" and "health care need"). Our findings indicate that public attitudes cluster around the historical organization of health care, but also relate to current economic and demographic realities. Individuals in countries adopting the "National Health Service Model" (the state directly provides health care but complete state control is absent) or the "Centralized Model" (the state directly provides health care and has much control) are more supportive of government involvement in health care than those in the "Insurance Model" (the state is limited to maintenance of the system) countries. However citizens in countries currently spending more on health care and having a greater burden of chronic illness are less supportive. Our results cast doubt on arguments that increased cost will result in a questioning of the contract between the state and citizens in the social provision of health care. We end by discussing implications for recent work in

  12. Prior Exercise Lowers Blood Pressure During Simulated Night-Work With Different Meal Schedules

    Science.gov (United States)

    Fullick, Sarah; Morris, Chris; Jones, Helen; Atkinson, Greg

    2009-01-01

    BACKGROUND Shift-work and a sedentary lifestyle are risk factors for raised blood pressure (BP). Exercise can reduce BP in diurnally-active individuals, but it is unknown whether postexercise hypotension persists when people are active and eating at night. We present the first investigation into the acute effects of exercise on BP monitored during simulated night-work. METHODS Nine normotensive participants, aged 20–42 years, completed at least two crossover trials beginning at 1800 hours. Between 1900 and 2000 hours, participants either rested or exercised at 50% peak oxygen uptake (VO2peak) and then remained awake throughout the night, completing various tasks until 0515 hours. Six participants completed a total of four trials in which they exercised or rested, whereas either one standardized (60 kJ/kg) meal at 2200 hours or two smaller (30 kJ/kg) meals at 2200 and 0200 hours were eaten. Systolic and diastolic BP, mean arterial pressure (MAP), heart rate (HR), and wrist activity were recorded every 30 min. RESULTS Following exercise, MAP was significantly (P < 0.0005) lower throughout the night-shift compared with no prior exercise (95% confidence limits for reduction: 4–7 mm Hg). The postexercise reductions in systolic BP and MAP were not moderated by diet, but the reduction in diastolic BP was slightly greater when only one meal was eaten (P < 0.0005). BP was lower even though wrist activity and HR were significantly higher following exercise (P < 0.0005). CONCLUSIONS These data indicate that prior exercise lowers BP throughout a subsequent 8-h night-shift in healthy individuals within the normotensive range. Therefore, regular low-intensity exercise might moderate the well-known association between shift-work participation and raised BP. PMID:19556971

  13. Isometric Back Exercise Has Different Effect on Pressure Pain Thresholds in Healthy Men and Women.

    Science.gov (United States)

    Gajsar, Hannah; Titze, Christina; Hasenbring, Monika Ilona; Vaegter, Henrik Bjarke

    2017-05-01

    Isometric exercises produce an acute decrease in the pain sensitivity, known as exercise-induced hypoalgesia (EIH). Existing EIH paradigms use exercises at the extremities with more pronounced EIH at local compared to remote body sites, indicating local inhibition in addition to central inhibitory mechanisms. So far the results on EIH in patients with low back pain (LBP) are equivocal and no studies have investigated an EIH paradigm targeting the lower back in order to assess EIH in patients with LBP. Thus, the aim of this pilot study was to assess pressure pain sensitivity at local and remote assessment sites, before and after an isometric back exercise in healthy women and men. In a pre-posttest design, pressure pain thresholds (PPT) were assessed at the lower back, biceps femoris muscle, and hand in 29 healthy subjects (17 women) before and after 120 seconds of the isometric Biering-Soerensen back extension test. After exercise, PPT increased significantly at the hand in women, but not in men ( P  = 0.027). Moreover, PPT at the leg increased independently of sex ( P  exercise approached significance ( P  = 0.07). The results of this pilot study indicate that isometric back exercise produces local and remote hypoalgesia. Remote EIH was only demonstrated in women, supporting the influence of sex in the hypoalgesic response after exercise. The effect of isometric back exercise on pain sensitivity in patients with low back pain should be investigated in future studies. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  14. Frequency of different blood groups and its association with BMI and blood pressure among the female medical students of Faisalabad.

    Science.gov (United States)

    Jawed, Shireen; Zia, Sadaf; Tariq, Sundus

    2017-08-01

    To determine the frequency of different blood groups among female medical students and to find the association of blood groups and body mass index with blood pressure. This cross-sectional study was performed at the University Medical and Dental College, Faisalabad, Pakistan, from March to April 2016, and comprised female medical students. Participants were divided into groups on the basis of their ABO blood groups and on body mass index criteria. Blood groups were determined by simple conventional slide method. Blood pressure was estimated by manual auscultatory technique with a mercury sphygmomanometer. Data was analysed usingSPSS20. There were 145 students with an overall mean age of18.4±0.75 years (range: 17-23 years). Blood group B was the predominant group 65(44.8%). Besides, 130(89.6%) subjects were rhesus positive and 23(53%) subjects of blood group O were pre-hypertensive. Multiple regression analysis indicated significant positive association of blood group O with both systolic and diastolic blood pressure (p=0.002, 0.001). However, subsequent logistic regression showed significant association only with diastolic blood pressure (p=0.001). Relative risk of pre-hypertension for obese (p=0.001) was greater than non-obese subjects. Body mass index was significantly associated with both systolic and diastolic blood pressure (p=0.004, 0.042). Blood group B was the most common blood group. Blood group O was associated with diastolic pre-hypertension, while body mass index was associated with both systolic and diastolic pre-hypertension.

  15. Non-cellulosic heteropolysaccharides from sugarcane bagasse - sequential extraction with pressurized hot water and alkaline peroxide at different temperatures.

    Science.gov (United States)

    Banerjee, Protibha Nath; Pranovich, Andrey; Dax, Daniel; Willför, Stefan

    2014-03-01

    The xylan-rich hemicellulose components of sugarcane bagasse were sequentially extracted with pressurized hot-water extraction (PHWE) and alkaline peroxide. The hemicelluloses were found to contain mainly arabinoxylans with varying substitutions confirmed by different chemical and spectroscopic methods. The arabinoxylans obtained from PHWE were found to be more branched compared to those obtained after alkaline extraction. Sequential extraction could be useful for the isolation of hemicelluloses with different degree of branching, molar mass, and functional groups from sugarcane bagasse, which can be of high potential use for various industrial applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Gender difference and economic gradients in the secular trend of population systolic blood pressure

    DEFF Research Database (Denmark)

    Andersen, Ulla; Jensen, Gorm B

    2013-01-01

    are treated without income associated treatment differences. In conclusion: Women in higher income groups have lower SBP than women in low-income groups and the gap between SBP in high-income women and low-income women increased with time. There were no significant differences in SBP-trend associated...

  17. Evolution effects of the copper surface morphology on the nucleation density and growth of graphene domains at different growth pressures

    Energy Technology Data Exchange (ETDEWEB)

    Hedayat, Seyed Mahdi [Transport Phenomena & Nanotechnology Lab., School of Chemical Engineering, College of Engineering, University of Tehran (Iran, Islamic Republic of); Karimi-Sabet, Javad, E-mail: j_karimi@alum.sharif.edu [NFCRS, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Shariaty-Niassar, Mojtaba, E-mail: mshariat@ut.ac.ir [Transport Phenomena & Nanotechnology Lab., School of Chemical Engineering, College of Engineering, University of Tehran (Iran, Islamic Republic of)

    2017-03-31

    Highlights: • Manipulation of the Cu surface morphology in a wide range by electropolishing treatment. • Comparison of the nucleation density of graphene at low pressure and atmospheric pressure CVD processes. • Controlling the evolution of the Cu surface morphology inside a novel confined space. • Growth of large-size graphene domains. - Abstract: In this work, we study the influence of the surface morphology of the catalytic copper substrate on the nucleation density and the growth rate of graphene domains at low and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) processes. In order to obtain a wide range of initial surface morphology, precisely controlled electropolishing methods were developed to manipulate the roughntreess value of the as-received Cu substrate (RMS = 30 nm) to ultra-rough (RMS = 130 nm) and ultra-smooth (RMS = 2 nm) surfaces. The nucleation and growth of graphene domains show obviously different trends at LPCVD and APCVD conditions. In contrast to APCVD condition, the nucleation density of graphene domains is almost equal in substrates with different initial roughness values at LPCVD condition. We show that this is due to the evolution of the surface morphology of the Cu substrate during the graphene growth steps. By stopping the surface sublimation of copper substrate in a confined space saturated with Cu atoms, the evolution of the Cu surface was impeded. This results in the reduction of the nucleation density of graphene domains up to 24 times in the pre-smoothed Cu substrates at LPCVD condition.

  18. Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry.

    Science.gov (United States)

    Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

    2016-09-30

    Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Twenty automotive workers were individually fitted out with three different pairs of safety shoes ( "normal" shoes, cushioned shoes, and midfoot bearing shoes). They walked at a given speed of 1.5 m/s. The CUELA measuring system and shoe insoles were used for gait analysis and plantar pressure measurements, respectively. Statistical analysis was conducted by ANOVA analysis for repeated measures. Walking with cushioned safety shoes or a midfoot bearing safety shoe led to a significant decrease of the average trunk inclination (pshoes as well as midfoot bearing shoes (pshoes. As expected, plantar pressure distributions varied significantly between cushioned or midfoot bearing shoes and shoes without ergonomic components. The overall function of safety shoes is the avoidance of injury in case of an industrial accident, but in addition, safety shoes could be a long-term preventive instrument for maintaining health of the employees' musculoskeletal system, as they are able to affect gait parameters. Further research needs to focus on safety shoes in working situations.

  19. The elastic properties, generalized stacking fault energy and dissociated dislocations in MgB2 under different pressure

    KAUST Repository

    Feng, Huifang

    2013-05-31

    The 〈112̄0〉 perfect dislocation in MgB2 is suggested to dissociate into two partial dislocations in an energy favorable way 〈112̄0〉 → 1/2 〈112̄0〉 + SF + 1/2 〈112̄0〉. This dissociation style is a correction of the previous dissociation 〈1000〉 → 1/3 〈11̄00〉 SF + 1/3 〈 2100〉proposed by Zhu et al. to model the partial dislocations and stacking fault observed by transmission electron microscopy. The latter dissociation results in a maximal stacking fault energy rather than a minimal one according to the generalized stacking fault energy calculated from first-principles methods. Furthermore, the elastic constants and anisotropy of MgB2 under different pressure are investigated. The core structures and mobilities of the 〈112̄0〉 dissociated dislocations are studied within the modified Peierls-Nabarro (P-N) dislocation theory. The variational method is used to solve the modified P-N dislocation equation and the Peierls stress is also determined under different pressure. High pressure effects on elastic anisotropy, core structure and Peierls stress are also presented. © 2013 Springer Science+Business Media New York.

  20. GDI fuel sprays of light naphtha, PRF95 and gasoline using a piezoelectric injector under different ambient pressures

    KAUST Repository

    Wu, Zengyang

    2018-03-20

    This study investigates fuel sprays of light naphtha (LN), primary reference fuel (PRF) and gasoline under different ambient pressures with an outwardly opening piezo gasoline direct injection (GDI) fuel injector. The tested gasoline fuel (regular grade with up to 10% ethanol, E10) was obtained by mixing fuels with AKI (the average of the research octane number (RON) and the motor octane number (MON)) of 87 from three local gas stations. Primary reference fuel (PRF) is commonly used as gasoline surrogate fuel and is blended by iso-octane and n-heptane. PRF95 is the blend of 95% iso-octane and 5% n-heptane by volume. LN fuel was provided by Saudi Aramco Oil Company. Five different ambient pressure conditions varied from 1 bar to 10 bar were tested. The spray was visualized by applying a Mie-scattering technique and a high-speed camera was employed to capture the spray images. The spray structure, spray angle, spray penetration length and spray front fluctuation were analyzed and compared among three fuels. Spray images show that a clear filamentary hollow-cone spray structure is formed for all three fuels at atmospheric conditions, and toroidal recirculation vortexes are observed at the downstream spray edges. A higher ambient pressure leads to a stronger vortex located closer to the injector outlet. Generally speaking, larger spray angles are found under higher ambient pressure conditions for all three fuels. Gasoline fuel always has the largest spray angle for each ambient pressure, while PRF95 has the smallest at most time. For each fuel, the spray front penetration length and spray front penetration velocity decrease with increasing ambient pressure. LN, PRF95 and gasoline show similar penetration length and velocity under the tested conditions. A two-stage spray front fluctuation pattern is observed for all three fuels. Stage one begins from the start of the injection and ends at 450–500 μs after the start of the injection trigger (ASOIT) with a slow

  1. Theoretical analysis and simulation of obstructed breakup of micro-droplet in T-junction under an asymmetric pressure difference

    Science.gov (United States)

    Fu, Yuhang; Bai, Lin; Jin, Yong; Cheng, Yi

    2017-03-01

    Asymmetric droplet breakup under a pressure difference at two outlets of a T-junction is investigated theoretically and numerically in this study. An accurate analysis of the evolution of droplet dynamics during the obstructed breakup process has been conducted. Meanwhile, the lattice Boltzmann method based on color gradient model is employed to simulate the system with the verification of the theoretical results. It is demonstrated that the Zou-He boundary setting at each outlet is advantageous for modifying the pressure drop of the two branches of T-junction. The results reveal that asymmetric breakup of the unequally sized droplets follows two steps, namely, the filling stage and the breakup stage. Then a universal parameter is proposed to describe the asymmetric condition of droplet breakup in T-junction, which plays a key role to characterize the temporal evolution of volume ratio and the droplet length of formed smaller droplets.

  2. Numerical Simulation of Geostress and Pore Pressure Evolution around Oil or Water Well under Different Injection-Production Ratio

    Directory of Open Access Journals (Sweden)

    Liu Jian-jun

    2013-01-01

    Full Text Available Geostress evolution in the process of oil field development can directly influence wellbore stability. Therefore, it is significant to strengthen the research of the evolution rule for well drilling and casing protection. Considering the interaction between reservoir seepage and stress fields, a mathematical model to characterize the stress evolution around wellbore was built. Using the FEM Software ABAQUS, through numerical simulation, the authors studied the evolution features of pore pressure and stress changes with time under different injection-production ratio, which disclosed the dynamic change regulation of pore pressure and stress of surrounding rock nearby the injection and production wells. These results may have implications in the treatment of wellbore stability and optimizing the injection and production processes during oil and gas production.

  3. Differences in perioperative femoral and radial arterial blood pressure in neonates and infants undergoing cardiac surgery requiring cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Hwa Jin Cho

    Full Text Available Abstract Objective: Several reports claim that blood pressure (BP in the radial artery may underestimate the accurate BP in critically ill patients. Here, the authors evaluated differences in mean blood pressure (MBP between the radial and femoral artery during pediatric cardiac surgery to determine the effectiveness of femoral arterial BP monitoring. Method: The medical records of children under 1 year of age who underwent open-heart surgery between 2007 and 2013 were retrospectively reviewed. Radial and femoral BP were measured simultaneously, and the differences between these values were analyzed at various times: after catheter insertion, after the initiation of cardiopulmonary bypass (CPB-on, after aortic cross clamping (ACC, after the release of ACC, after weaning from CPB, at arrival in the intensive care unit (ICU, and every 6 h during the first day in the ICU. Results: A total of 121 patients who underwent open-heart surgery met the inclusion criteria. During the intraoperative period, from the beginning to the end of CPB, radial MBPs were significantly lower than femoral MBPs at each time-point measured (p 60 min, odds ratio: 7.47 was a risk factor for lower radial pressure. However, discrepancies between these two values disappeared after arrival in the ICU. There was no incidence of ischemic complications associated with the catheterization of both arteries. Conclusion: The authors suggest that femoral arterial pressure monitoring can be safely performed, even in neonates, and provides more accurate BP values during CPB-on periods, and immediately after weaning from CPB, especially when CPB time was greater than 60 min.

  4. Gender difference in blood pressure, blood sugar, and cholesterol in young adults with comparable routine physical exertion

    Directory of Open Access Journals (Sweden)

    T S Anish

    2013-01-01

    Full Text Available Context: Gender differences in the risk of developing non-communicable diseases (NCD are a matter of debate. The susceptibility of a woman to NCD should be evaluated taking into consideration the social factors that limit the physical activity among women. It will be interesting to note what will happen if women are allowed to take part in physical exercise to the extent of men. Aims: To find out the gender difference in the pattern of the clinical and biochemical indices related to NCD in young adults with comparable daily physical activity. Settings and Design: This is an institution-based cross-sectional study and the setting was Lekshmibhai National College for Physical Education (LNCPE, Thiruvananthapuram, Kerala, India. Materials and Methods: The study participants were students who were regularly involved in more than three hours of physical exercise daily at least for the previous one year. The information on socio-demography, anthropometry, and blood pressure was recorded. Blood samples were taken for laboratory examination. Results: Out of 150 students registered, 126 (84% in the age group of 17 to 25 years who fulfilled the eligibility criteria were studied. Fifty-five (43.7% of them were women. Systolic blood pressure, fasting blood sugar, and low-density lipoprotein were found significantly lower in women. No significant difference was noted in the case of diastolic blood pressure and total cholesterol. Conclusion: Gender differences exist for NCD risk factors among young adults with comparable physical activity and physical exertion seems to be more protective for females.

  5. A Study on Anthropometric Measurements, Blood Pressure, Blood Sugar and Food Intakes Among Different Social Status and Ethnicities

    Directory of Open Access Journals (Sweden)

    Jafarirad

    2016-09-01

    Full Text Available Background Metabolic syndrome is a disorder that increases the risk of cardiovascular disease and diabetes. Objectives The aim of the study was to evaluate some risk factors of the metabolic syndrome and food intakes among people who lived in Ahvaz City, Iran. Methods It was a filed study that was conducted on 211 subjects who participated in health exhibition. Socioeconomic status and ethnicity were asked by a general questionnaire. Weight, height, body mass index, waist circumference (WC and WC to hip circumference ratio (WHR were obtained. Blood sugar was measured by a glucometer. Systolic and diastolic blood pressures were obtained and dietary intakes were assessed by a brief instrument. Results There was a significant difference in weight, height, WC, WHR and systolic blood pressure among different jobs. Workers had more intakes of cake and sweets. Arab subjects had more intakes of bread and fishes and Persians more intakes of vegetables. Soda, chocolate and candy were more consumed by Kurd ethnicity. Conclusions Job may be accounted as an important effective socioeconomic factor related to metabolic syndrome risk factors; also different cultures due to different ethnicities may have an influence on lifestyle and dietary intakes.

  6. Modeling Study: Mechanism of Foam Propagation in Porous Media at Different Levels of Minimum Mobilization Pressure Gradient

    Science.gov (United States)

    Izadi, M.; Kam, S.

    2017-12-01

    Scope: Numerous laboratory and field tests revealed that foam can effectively control gas mobility and improve sweep efficiency in enhanced-oil-recovery and subsurface-remediation processes, if correctly designed. The objective of this study is to answer (i) how mechanistic foam model parameters can be determined by fitting lab experiments in a step-by-step manner; (ii) how different levels of mobilization pressure gradient for foam generation affects the fundamentals of foam propagation; and (iii) how foam propagation distance can be estimated in the subsurface. This study for the first time shows why, and by how much, supercritical CO2 foams are advantaged over other types of foams such as N2 foam. Methods: First of all, by borrowing experimental data existing in the literature, this study shows how to capture mechanistic foam model parameters. The model, then, is applied to a wide range of mobilization pressure gradient to represent different types of foams that have been applied in the field (Note that supercritical CO2 foams exhibit much lower mobilization pressure compared to other types of foams (N2, steam, air, etc.). Finally, the model and parameters are used to evaluate different types of foam injection scenarios in order to predict how far foams can propagate with what properties in the field condition. Results and Conclusions: The results show that (i) the presence of three different foam states (strong, weak, intermediate) as well as two different strong-foam flow regimes (high-quality and low-quality regimes) plays a key role in model fit and field-scale propagation prediction and (ii) the importance of complex non-Newtonian foam rheology should not be underestimated. More specifically, this study finds that (i) supercritical CO2 foams can propagate a few hundreds of feet easily, which is a few orders of magnitude higher than other foams such as N2 foams; (ii) for dry foams (or, strong foams in the high-quality regime), the higher gas fractions the

  7. Ethnic differences in the effect of environmental stressors on blood pressure and hypertension in the Netherlands

    NARCIS (Netherlands)

    Agyemang, Charles; van Hooijdonk, Carolien; Wendel-Vos, Wanda; Ujcic-Voortman, Joanne K.; Lindeman, Ellen; Stronks, Karien; Droomers, Mariel

    2007-01-01

    BACKGROUND: Evidence strongly suggests that the neighbourhood in which people live influences their health. Despite this, investigations of ethnic differences in cardiovascular risk factors have focused mainly on individual-level characteristics. The main purpose of this study was to investigate

  8. Corrosion kinetics at high pressure and temperature of Zr-2.5 Nb with different heat treatments

    International Nuclear Information System (INIS)

    Jaime Solis, F.; Bordoni, Roberto; Olmedo, Ana M.; Villegas, Marina; Miyagusuku, Marcela

    2003-01-01

    The corrosion behaviour of Zr-2.5 Nb pressure tube (PT) specimens, with ageing treatments at 400 and 500 C degrees for different times, was studied. The results were analyzed using the corrosion behavior of Zr-20 Nb and Zr-1 Nb samples heat treated during 1 hour at 850 C degrees, cooled in air and aged at the same temperature and times than the PT specimens. The comparison between the corrosion behaviour of Zr-1 Nb and Zr-20 Nb aged coupons with the aged pressure tube specimens, together with the metal/oxide interface morphology of Zr-2.5 Nb specimens, suggest that the increase in the corrosion resistance in the latter coupons is associated with the decomposition of the β-Zr phase. There is also a contribution of α-Zr phase when the ageing temperatures are high enough or the ageing times are long enough, due to a decrease in the Nb content of this phase. This last contribution is associated with an increase in the corrosion resistance of the central zone of pressure tube in the reactor. (author)

  9. Properties of the pressure-induced extended-solid carbon monoxide under different synthesis and processing conditions

    Science.gov (United States)

    Dang, Nhan; Ciezak-Jenkins, Jennifer

    2017-06-01

    The discovery of the high-energy-density pressure-induced extended-solid/polymeric carbon monoxide (poly-CO) has opened a new paradigm of energetic materials. Considerable studies have been made to understand properties of poly-CO. However factors which control the morphology and meta-stability of recovered samples at ambient conditions have not been identified. In this presentation, we report the variations of morphology and meta-stability of poly-CO synthesized under different conditions in the GPa range. It has been found that the morphology and meta-stability of poly-CO depend on sample volume, rate of polymeric phase transition and additives. Poly-CO synthesized with a faster compression rate appears to be more structurally disordered and have higher rates of decomposition. Samples synthesized in a larger volume require either a longer time at elevated pressure or a higher pressure for the polymeric phase transitions to occur. Also, results of kinetic studies of photochemical reaction of CO at 4.5 GPa in presence of traces of H2 O, HCl (1M), and concentrated H2SO4 will be presented and influences of these additives on the morphology and meta-stability of polymeric CO will be discussed.

  10. [Mechanisms of sympathetic activity in rats exposed to different patterns of hypoxia and the correlation with blood pressure].

    Science.gov (United States)

    He, Ruoxi; Su, Xiaoli; Xiang, Yonghong; Hu, Chengping; Luo, Yingquan

    2011-10-01

    To observe the effects of two different hypoxia patterns on blood pressure and the underlying mechanisms. Eighteen male SD rats were randomly divided into three groups: the intermittent hypoxia group (IH group), the continuous hypoxia group (CH group) and the normal control group (NC group). The rats of the IH and CH group were subjected to intermittent hypoxia (7 h/d) and continuous hypoxia (7 h/d) for 42 days respectively. The NC group rats were untreated. The levels of arteria caudilis systolic pressure (ACSP) were measured with noninvasive rats arteria caudilis gauge before the experiment, at the end of 3rd, 6th week of the experiment. The concentrations of norepinephrine (NE) in serum and neuropeptide Y (NPY) in plasma were respectively measured by enzyme-linked-immunosorbent assay (ELISA) and radioimmunoassay. The contents of malondialdehyde (MDA) and the ability of inhibiting hydroxyl free radical in serum were analyzed by thiobarbituric acid colorimetric analysis (TBAR) at the end of 6th week. At the end of 3rd week, the levels of ACSP were considerably higher than those before the treatment (P0.05). The levels of NE, NPY and MDA were positively related with ACSP (r=0.873, Phigh blood pressure, which may be related to the sympathetic over-activity and the oxidative stress.

  11. Pasteurization of fruit juices of different pH values by combined high hydrostatic pressure and carbon dioxide.

    Science.gov (United States)

    Li, Wang; Pan, Jian; Xie, Huiming; Yang, Yi; Zhou, Dianfei; Zhu, Zhaona

    2012-10-01

    The inactivation of the selected vegetative bacteria Escherichia coli, Listeria innocua, and Lactobacillus plantarum by high hydrostatic pressure (HHP) in physiological saline (PS) and in four fruit juices with pHs ranging from 3.4 to 6.3, with or without dissolved CO(2), was investigated. The inactivation effect of HHP on the bacteria was greatly enhanced by dissolved CO(2). Effective inactivation (>7 log) was achieved at 250 MPa for E. coli and 350 MPa for L. innocua and L. plantarum in the presence of 0.2 M CO(2) at room temperature for 15 min in PS, with additional inactivation of more than 4 log for all three bacteria species compared with the results with HHP treatment alone. The combined inactivation by HHP and CO(2) in tomato juice of pH 4.2 and carrot juice of pH 6.3 showed minor differences compared with that in PS. By comparison, the combined effect in orange juice of pH 3.8 was considerably promoted, while the HHP inactivation was enhanced only to a limited extent. In another orange juice with a pH of 3.4, all three strains lost their pressure resistance. HHP alone completely inactivated E. coli at relatively mild pressures of 200 MPa and L. innocua and L. plantarum at 300 MPa. Observations of the survival of the bacteria in treated juices also showed that the combined treatment caused more sublethal injury, which increased further inactivation at a relatively mild pH of 4.2 during storage. The results indicated that the combined treatment of HHP with dissolved CO(2) may provide an effective method for the preservation of low- or medium-acid fruit and vegetable juices at relatively low pressures. HHP alone inactivated bacteria effectively in high-acid fruit juice.

  12. Agreement of high definition oscillometry with direct arterial blood pressure measurement at different blood pressure ranges in horses under general anaesthesia.

    Science.gov (United States)

    Tünsmeyer, Julia; Hopster, Klaus; Feige, Karsten; Kästner, Sabine Br

    2015-05-01

    To determine the agreement of high definition oscillometry (HDO) with direct arterial blood pressure measurements in normotensive, hypotensive and hypertensive horses during general anaesthesia. Experimental study. Seven healthy warmblood horses, aged 3-11 years, weighing 470-565 kg. Measurements from a HDO device with the cuff placed around the base of the tail were compared with pressures measured invasively from the facial artery. High blood pressures were induced by intravenous (IV) administration of dobutamine (5 μg kg(-1) minute(-1)) over ten minutes followed by norepinephrine (0.1 mg kg(-1) IV) and low pressures by increasing the inspired fraction of isoflurane and administration of nitroglycerine (0.05 mg kg(-1) IV). For analysis three pressure levels were determined: high (MAP>110 mmHg), normal (60 mmHgstandard deviation for SAP, MAP and DAP were 0.1 ± 19.4 mmHg, 0.5 ± 14.0, 4.7 ± 15.6, respectively. At high pressure levels bias and SD were 26.1 ± 37.3 (SAP), 4.2 ± 19.4 (MAP), 1.5 ± 16.8 (DAP) and at low pressures -20.0 ± 20.9 (SAP), -11.4 ± 19.6 (MAP), -4.7 ± 20.1 (DAP), with HDO measurements at a MAP <50 mmHg often failing. Good agreement with invasive arterial blood pressures was obtained with HDO at normotensive levels in horses. At high and low pressure ranges HDO was unreliable. Therefore, if haemodynamic instability is expected, invasive measurement remains preferable. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  13. Single-sided natural ventilation driven by wind pressure and temperature difference

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Heiselberg, Per

    2008-01-01

    Even though opening a window for ventilation of a room seems very simple, the flow that occurs in this situation is rather complicated. The amount of air going through the window opening will depend on the wind speed near the building, the temperatures inside and outside the room, the wind direct...... on the ratio between the forces and the wind direction. This change is also found in the velocity profiles measured in the opening, which might change from wind dominated to temperature dominated under the same wind direction but with increasing temperature difference.......Even though opening a window for ventilation of a room seems very simple, the flow that occurs in this situation is rather complicated. The amount of air going through the window opening will depend on the wind speed near the building, the temperatures inside and outside the room, the wind......-scale wind tunnel experiments have been made with the aim of making a new expression for calculation of the airflow rate in single-sided natural ventilation. During the wind tunnel experiments it was found that the dominating driving force differs between wind speed and temperature difference depending...

  14. Different patterns of fornix damage in idiopathic normal pressure hydrocephalus and Alzheimer disease.

    Science.gov (United States)

    Hattori, T; Sato, R; Aoki, S; Yuasa, T; Mizusawa, H

    2012-02-01

    The fornix contains efferent fibers of the hippocampus and is in close contact with the corpus callosum. Part of the fornix is directly attached to the corpus callosum, and another part is suspended from the corpus callosum via the septum pellucidum. DTI can be used to evaluate the morphology and microstructural integrity of the fornix. We examined the pattern of fornix damage in patients with iNPH or AD. We enrolled 22 patients with iNPH, 20 with AD, and 20 healthy controls. DTI data were obtained. The morphology (volume, length, and mean cross-sectional area) and FA values of the fornix were evaluated by using tract-specific analysis and compared among groups. The volume, cross-sectional area, and FA value of the fornix were significantly smaller in patients with iNPH than in controls, whereas the length was significantly greater. In patients with AD, the volume, mean cross-sectional area, and FA value of the fornix were significantly smaller than those in controls, whereas the length was not altered. The fornix was significantly longer in patients with iNPH than in patients with AD, whereas the volume and cross-sectional areas were significantly smaller. Our results suggest that the different pathogeneses of these diseases lead to fornix damage through different mechanisms: through mechanical stretching due to lateral ventricular enlargement and corpus callosum deformation in patients with iNPH, and through degeneration secondary to hippocampal atrophy in patients with AD.

  15. A sound pressure field during the quenching of a steel specimen in different water solutions

    Directory of Open Access Journals (Sweden)

    J. Prezelj

    2011-01-01

    Full Text Available The purpose of controlling the quenching process of an orange-hot steel workpiece is to ensure its required surface hardness. A sound in a cooling liquid generated by the quenching process was experimentally analyzed. It contains sufficient information about the ongoing process for its quantification, and it can be used in real time. Traditionally, the quenching and the resultant hardening can be controlled by selecting different process parameters, like, for example the characteristics of the cooling liquid, the velocity of the cooling liquid flow, its temperature, the temperature of the work-piece, and many others. The possibility of controlling the quenching process by using acoustic cavitation is considered in this article.

  16. Analysis on the Spatial Difference of Bacterial Community Structure in Micro-pressure Air-lift Loop Reactor

    Science.gov (United States)

    Wan, L. G.; Lin, Q.; Bian, D. J.; Ren, Q. K.; Xiao, Y. B.; Lu, W. X.

    2018-02-01

    In order to reveal the spatial difference of the bacterial community structure in the Micro-pressure Air-lift Loop Reactor, the activated sludge bacterial at five different representative sites in the reactor were studied by denaturing gradient gel electrophoresis (DGGE). The results of DGGE showed that the difference of environmental conditions (such as substrate concentration, dissolved oxygen and PH, etc.) resulted in different diversity and similarity of microbial flora in different spatial locations. The Shannon-Wiener diversity index of the total bacterial samples from five sludge samples varied from 0.92 to 1.28, the biodiversity index was the smallest at point 5, and the biodiversity index was the highest at point 2. The similarity of the flora between the point 2, 3 and 4 was 80% or more, respectively. The similarity of the flora between the point 5 and the other samples was below 70%, and the similarity of point 2 was only 59.2%. Due to the different contribution of different strains to the removal of pollutants, it can give full play to the synergistic effect of bacterial degradation of pollutants, and further improve the efficiency of sewage treatment.

  17. A Comparative Study on Energy and Exergy Analyses of a CI Engine Performed with Different Multiple Injection Strategies at Part Load: Effect of Injection Pressure

    OpenAIRE

    Özkan, Muammer

    2015-01-01

    In this study, a four stroke four cylinder direct injection CI engine was run using three different injection pressures. In all measurements, the fuel quantity per cycle, the pre injection and main injection timing, the boost pressure and the engine speed were kept constant. The motor tests were performed under 130, 140 and 150 MPa rail pressure. During the theoretical part of the study, combustion, emission, energy and exergy analysis were made using the test results. An increase in the inje...

  18. Dissemination of bacteria labeled with technetium-99m after laparotomy and abdominal insufflation with different CO2 pressures on rats

    International Nuclear Information System (INIS)

    Pitombo, Marcos Bettini; Faria, Clarice Abreu dos Santos Albuquerque de; Steinbruck, Klaus; Bernardo, Luciana Camargo; Bernardo Filho, Mario

    2008-01-01

    Purpose: To asses the dissemination of bacteria labeled with technetium-99m (99mTc) from peritoneal cavity after different surgical procedures. Methods: Bacteria of the Escherichia coli species labeled with 99mTc were used in a concentration of 108 units of colony-makers for ml (UFC/ml) and 1 ml was inoculated through intra-peritoneal via. Forty-eight rats were divided into four groups: control, laparotomy, pneumoperitoneum with 10 mmHg and pneumoperitoneum with 20 mmHg of CO2. Procedures were performed 20 min after injection of the inoculum and lasted 30 min. Animals were sacrificed after six hours (Group 1) and 24 hours (Group 2). Samples of blood, liver and spleen were collected for radioactivity counting. Results: After six hours, indirect detection of the bacteria in different organs was uniform in all groups. After 24 hours, a larger detection of technetium was observed in the livers of animals of the group insufflated with 20 mmHg of CO2, when compared with those of control group (p<0.01). The other groups did not present statistically significant variations. Conclusions: The use of a higher intra-abdominal pressure was associated with a higher bacterial dissemination to the liver. The application of lower intra-abdominal pressures may be associated with a lower dissemination of the infectious status during laparoscopic approach of peritonitis status. (author)

  19. Predation determines different selective pressure on pea aphid host races in a complex agricultural mosaic.

    Directory of Open Access Journals (Sweden)

    Adalbert Balog

    Full Text Available Field assessments were conducted to examine the interplay between host plant and predation in complex agricultural mosaic on pea aphid clover and alfalfa races. In one experiment, we examined the relative fitness on clover race (CR and alfalfa race (AR pea aphids on broad bean, red clover and alfalfa alone. But because clover is typically grown in a more complex agricultural mosaic with alfalfa and broad bean, a second experiment was conducted to assess the fitness consequences under predation in a more complex agricultural field setting that also included potential apparent competition with AR pea aphids. In a third experiment we tested for the effect of differential host race density on the fitness of the other host race mediated by a predator effect. CR pea aphids always had fitness losses when on broad bean (had lower fitness on broad bean relative to red clover and fitness benefits when on red clover (higher fitness on red clover relative to broad bean, whether or not in apparent competition with alfalfa race aphids on bean and alfalfa. AR suffered fitness loss on both alfalfa and bean in apparent competition with CR on clover. Therefore we can conclude that the predation rate between host races was highly asymmetrical. The complexity of the agricultural mosaic thus can influence prey selection by predators on different host plants. These may have evolutionary consequences through context dependent fitness benefits on particular host plants.

  20. An explorative investigation of functional differences in plantar center of pressure of four foot types using sample entropy method.

    Science.gov (United States)

    Mei, Zhanyong; Ivanov, Kamen; Zhao, Guoru; Li, Huihui; Wang, Lei

    2017-04-01

    In the study of biomechanics of different foot types, temporal or spatial parameters derived from plantar pressure are often used. However, there is no comparative study of complexity and regularity of the center of pressure (CoP) during the stance phase among pes valgus, pes cavus, hallux valgus and normal foot. We aim to analyze whether CoP sample entropy characteristics differ among these four foot types. In our experiment participated 40 subjects with normal feet, 40 with pes cavus, 19 with pes valgus and 36 with hallux valgus. A Footscan ® system was used to collect CoP data. We used sample entropy to quantify several parameters of the investigated four foot types. These are the displacement in medial-lateral (M/L) and anterior-posterior (A/P) directions, as well as the vertical ground reaction force of CoP during the stance phase. To fully examine the potential of the sample entropy method for quantification of CoP components, we provide results for two cases: calculating the sample entropy of normalized CoP components, as well as calculating it using the raw data of CoP components. We also explored what are the optimal values of parameters m (the matching length) and r (the tolerance range) when calculating the sample entropy of CoP data obtained during the stance phases. According to statistical results, some factors significantly influenced the sample entropy of CoP components. The sample entropies of non-normalized A/P values for the left foot, as well as for the right foot, were different between the normal foot and pes valgus, and between the normal foot and hallux valgus. The sample entropy of normalized M/L displacement of the right foot was different between the normal foot and pes cavus. The measured variable for A/P and M/L displacements could serve for the study of foot function.

  1. Survival in macaroni penguins and the relative importance of different drivers: individual traits, predation pressure and environmental variability.

    Science.gov (United States)

    Horswill, Catharine; Matthiopoulos, Jason; Green, Jonathan A; Meredith, Michael P; Forcada, Jaume; Peat, Helen; Preston, Mark; Trathan, Phil N; Ratcliffe, Norman

    2014-09-01

    Understanding the demographic response of free-living animal populations to different drivers is the first step towards reliable prediction of population trends. Penguins have exhibited dramatic declines in population size, and many studies have linked this to bottom-up processes altering the abundance of prey species. The effects of individual traits have been considered to a lesser extent, and top-down regulation through predation has been largely overlooked due to the difficulties in empirically measuring this at sea where it usually occurs. For 10 years (2003-2012), macaroni penguins (Eudyptes chrysolophus) were marked with subcutaneous electronic transponder tags and re-encountered using an automated gateway system fitted at the entrance to the colony. We used multistate mark-recapture modelling to identify the different drivers influencing survival rates and a sensitivity analysis to assess their relative importance across different life stages. Survival rates were low and variable during the fledging year (mean = 0·33), increasing to much higher levels from age 1 onwards (mean = 0·89). We show that survival of macaroni penguins is driven by a combination of individual quality, top-down predation pressure and bottom-up environmental forces. The relative importance of these covariates was age specific. During the fledging year, survival rates were most sensitive to top-down predation pressure, followed by individual fledging mass, and finally bottom-up environmental effects. In contrast, birds older than 1 year showed a similar response to bottom-up environmental effects and top-down predation pressure. We infer from our results that macaroni penguins will most likely be negatively impacted by an increase in the local population size of giant petrels. Furthermore, this population is, at least in the short term, likely to be positively influenced by local warming. More broadly, our results highlight the importance of considering multiple causal effects across

  2. Neurotrophin levels in different regions of the placenta and their association with birth outcome and blood pressure.

    Science.gov (United States)

    Sahay, A S; Sundrani, D P; Wagh, G N; Mehendale, S S; Joshi, S R

    2015-08-01

    Our recent study in preeclampsia indicates differential oxidative stress in various regions of the placenta. Oxidative stress is known to influence neurotrophin levels. We therefore hypothesize that placental regional differences in oxidative stress will also lead to differences in neurotrophin levels. The current study examines the levels of neurotrophins, brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in different regions of the placenta in 50 normotensive control women and 47 women with preeclampsia (21 delivering at term and 26 delivering preterm). Placentae were collected from four different regions: central maternal (CM), central fetal (CF), peripheral maternal (PM) and peripheral fetal (PF). BDNF levels were higher in CF region as compared to CM (p placenta in the control group. There was no regional change in NGF levels in any of the groups. Analysis between groups indicated higher NGF levels in CM (p < 0.01), PM (p < 0.05) and PF (p < 0.01) regions of preterm preeclampsia group as compared to control. Negative association of NGF levels in CM, CF and PM regions with baby weight and in CF, PM and PF regions with baby length was observed. NGF levels in all four regions were positively associated with systolic blood pressure. Our data indicates regional differences in levels of BDNF only in normotensive control but not in preeclampsia group. Higher NGF levels in preterm preeclampsia may be a response to increased oxidative stress. This may have implications for altered placental development in preeclampsia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effect of Different Head Positions in Lateral Decubitus Posture on Intraocular Pressure in Treated Patients With Open-Angle Glaucoma.

    Science.gov (United States)

    Lee, Tae-Eun; Yoo, Chungkwon; Lin, Shan C; Kim, Yong Yeon

    2015-11-01

    To investigate the effects of different head positions in the lateral decubitus posture on intraocular pressure (IOP) in medically treated patients with open-angle glaucoma (OAG). Prospective observational study. setting: Institutional. Twenty patients with bilateral OAG who received only latanoprost as treatment. IOP was measured using an ICare Pro tonometer in the sitting, supine, right, and left lateral decubitus posture. In lateral decubitus posture, IOP measurements were taken with 3 different head positions (30 degrees higher than, 30 degrees lower than, and parallel to the center of the thoracic vertebra) in a randomized sequence. Comparison of the IOPs between the dependent (lower-sided) and nondependent eyes in the lateral decubitus postures with different head positions. We also analyzed the differences in IOPs between the better and worse eyes. IOP was higher in the dependent eyes than in the nondependent eyes in lateral decubitus posture, regardless of the head position (all P posture or head position were not significantly different between the better and worse eyes. Low head position elevates IOP of the dependent eyes of medically treated OAG patients compared with neutral head position in the lateral decubitus posture. Adjustment of the height of a pillow may help mitigate IOP elevations resulting from lying on the side with a low or no pillow in glaucoma patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean.

    Science.gov (United States)

    Grimsditch, G; Pisapia, C; Huck, M; Karisa, J; Obura, D; Sweet, M

    2017-10-01

    This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as 'stress tolerant' showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of 'competitive' corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for 'competitive' corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of 'stress tolerant' and 'generalist' coral genera. Copyright © 2017. Published by Elsevier Ltd.

  5. Computing the influences of different Intraocular Pressures on the human eye components using computational fluid-structure interaction model.

    Science.gov (United States)

    Karimi, Alireza; Razaghi, Reza; Navidbakhsh, Mahdi; Sera, Toshihiro; Kudo, Susumu

    2017-01-01

    Intraocular Pressure (IOP) is defined as the pressure of aqueous in the eye. It has been reported that the normal range of IOP should be within the 10-20 mmHg with an average of 15.50 mmHg among the ophthalmologists. Keratoconus is an anti-inflammatory eye disorder that debilitated cornea unable to reserve the normal structure contrary to the IOP in the eye. Consequently, the cornea would bulge outward and invoke a conical shape following by distorted vision. In addition, it is known that any alterations in the structure and composition of the lens and cornea would exceed a change of the eye ball as well as the mechanical and optical properties of the eye. Understanding the precise alteration of the eye components' stresses and deformations due to different IOPs could help elucidate etiology and pathogenesis to develop treatments not only for keratoconus but also for other diseases of the eye. In this study, at three different IOPs, including 10, 20, and 30 mmHg the stresses and deformations of the human eye components were quantified using a Three-Dimensional (3D) computational Fluid-Structure Interaction (FSI) model of the human eye. The results revealed the highest amount of von Mises stress in the bulged region of the cornea with 245 kPa at the IOP of 30 mmHg. The lens was also showed the von Mises stress of 19.38 kPa at the IOPs of 30 mmHg. In addition, by increasing the IOP from 10 to 30 mmHg, the radius of curvature in the cornea and lens was increased accordingly. In contrast, the sclera indicated its highest stress at the IOP of 10 mmHg due to over pressure phenomenon. The variation of IOP illustrated a little influence in the amount of stress as well as the resultant displacement of the optic nerve. These results can be used for understanding the amount of stresses and deformations in the human eye components due to different IOPs as well as for clarifying significant role of IOP on the radius of curvature of the cornea and the lens.

  6. Development of a tapered cell drift chamber II: operation in high magnetic fields and different gas pressures

    International Nuclear Information System (INIS)

    Blissett, J.A.; Hasell, D.K.; Parham, A.G.; Payne, B.T.; Saxon, D.H.

    1985-11-01

    Several designs for drift cells have been constructed and tested in an electron beam at DESY. The designs tested consisted of pairs of adjacent tapered cells, of eight sense wires each, to simulate a portion of a layer of drift cells in a central tracking detector. Tests were made to study the operation and resolution of the drift cells under a variety of conditions. Ar:C 2 H 6 (50:50) and Ar:CO 2 :CH 4 (90:9:1) gas mixtures were used at absolute pressures of one to four bar for the former and at one bar for the latter. Measurements were made at different electric drift fields in conjunction with magnetic fields varying from 0 to 1.82 T. Aspects of the construction, electronics and operation are discussed and results regarding the resolution as a function of drift distance and operating conditions are presented with some model calculations. (author)

  7. Differing prognostic value of pulse pressure in patients with heart failure with reduced or preserved ejection fraction

    DEFF Research Database (Denmark)

    Jackson, Colette E; Castagno, Davide; Maggioni, Aldo P

    2015-01-01

    AIMS: Low pulse pressure is a marker of adverse outcome in patients with heart failure (HF) and reduced ejection fraction (HF-REF) but the prognostic value of pulse pressure in patients with HF and preserved ejection fraction (HF-PEF) is unknown. We examined the prognostic value of pulse pressure......) and 5008 with HF-PEF (828 deaths). Pulse pressure was analysed in quintiles in a multivariable model adjusted for the previously reported Meta-Analysis Global Group in Chronic Heart Failure prognostic variables. Heart failure and reduced ejection fraction patients in the lowest pulse pressure quintile had...

  8. Stability Analysis of Hydrodynamic Pressure Landslides with Different Permeability Coefficients Affected by Reservoir Water Level Fluctuations and Rainstorms

    Directory of Open Access Journals (Sweden)

    Faming Huang

    2017-06-01

    Full Text Available It is significant to study the variations in the stability coefficients of hydrodynamic pressure landslides with different permeability coefficients affected by reservoir water level fluctuations and rainstorms. The Sifangbei landslide in Three Gorges Reservoir area is used as case study. Its stability coefficients are simulated based on saturated-unsaturated seepage theory and finite element analysis. The operating conditions of stability coefficients calculation are reservoir water level variations between 175 m and 145 m, different rates of reservoir water level fluctuations, and a three-day continuous rainstorm. Results show that the stability coefficient of the hydrodynamic pressure landslide decreases with the drawdown of the reservoir water level, and a rapid drawdown rate leads to a small stability coefficient when the permeability coefficient ranges from 1.16 × 10−6 m/s to 4.64 × 10−5 m/s. Additionally, the landslide stability coefficient increases as the reservoir water level increases, and a rapid increase in the water level leads to a high stability coefficient when the permeability coefficient ranges from 1.16 × 10−6 m/s to 4.64 × 10−5 m/s. The landslide stability coefficient initially decreases and then increases as the reservoir water level declines when the permeability coefficient is greater than 4.64 × 10−5 m/s. Moreover, for structures with the same landslide, the landslide stability coefficient is most sensitive to the change in the rate of reservoir water level drawdown when the permeability coefficient increases from 1.16 × 10−6 m/s to 1.16 × 10−4 m/s. Additionally, the rate of decrease in the stability coefficient increases as the permeability coefficient increases. Finally, the three-day rainstorm leads to a significant reduction in landslide stability, and the rate of decrease in the stability coefficient initially increases and then decreases as the permeability coefficient increases.

  9. Photosynthesis Decrease and Stomatal Control of Gas Exchange in Abies alba Mill. in Response to Vapor Pressure Difference.

    Science.gov (United States)

    Guehl, J M; Aussenac, G

    1987-02-01

    The responses of steady state CO(2) assimilation rate (A), transpiration rate (E), and stomatal conductance (g(s)) to changes in leaf-to-air vapor pressure difference (DeltaW) were examined on different dates in shoots from Abies alba trees growing outside. In Ecouves, a provenance representative of wet oceanic conditions in Northern France, both A and g(s) decreased when DeltaW was increased from 4.6 to 14.5 Pa KPa(-1). In Nebias, which represented the dry end of the natural range of A. alba in southern France, A and g(s) decreased only after reaching peak levels at 9.0 and 7.0 Pa KPa(-1), respectively. The representation of the data in assimilation rate (A) versus intercellular CO(2) partial pressure (C(i)) graphs allowed us to determine how stomata and mesophyll photosynthesis interacted when DeltaW was increased. Changes in A were primarily due to alterations in mesophyll photosynthesis. At high DeltaW, and especially in Ecouves when soil water deficit prevailed, A declined, while C(i) remained approximately constant, which may be interpreted as an adjustment of g(s) to changes in mesophyll photosynthesis. Such a stomatal control of gas exchange appeared as an alternative to the classical feedforward interpretation of E versus DeltaW responses with a peak rate of E. The gas exchange response to DeltaW was also characterized by considerable deviations from the optimization theory of IR Cowan and GD Farquhar (1977 Symp Soc Exp Biol 31: 471-505).

  10. Analysis of different anthropometric indicators in the detection of high blood pressure in school adolescents: a cross-sectional study with 8295 adolescents.

    Science.gov (United States)

    Christofaro, Diego G D; Farah, Breno Q; Vanderlei, Luiz Carlos M; Delfino, Leandro D; Tebar, William R; Barros, Mauro Virgílio G de; Ritti-Dias, Raphael M

    High blood pressure is strongly associated with obesity in different populations. However, it is unclear whether different anthropometric indicators of obesity can satisfactorily predict high blood pressure in the school setting. This study evaluated the sensitivity and specificity of body mass index, waist circumference, and waist to height ratio in the detection of high blood pressure in adolescents. The sample consisted of 8295 adolescents aged 10-17 years. Weight was measured using a digital scale, height with a stadiometer, and waist circumference using a tape measure. Blood pressure was measured by an automatic blood pressure measuring device. ROC curves were used for the analysis of sensitivity and specificity of the three anthropometric indices in identifying high blood pressure. Binary Logistic Regression was used to assess the association of body mass index, waist circumference, and waist to height ratio with high blood pressure. Low values of sensitivity were observed for body mass index (0.35), waist circumference (0.37), and waist to height ratio (0.31) and high values of specificity for body mass index (0.86), waist circumference (0.82), and waist to height ratio (0.83) in the detection of high blood pressure. An association was observed between adolescents classified with high body mass index (OR=3.57 [95% CI=3.10-4.10]), waist cirumference (OR=3.24 [95% CI=2.83-3.72]), and waist to height ratio (OR=2.94 [95% CI=2.54-3.40]) with high blood pressure. Body mass index, waist circumference, and waist to height ratio presented low sensitivity to identify adolescents with high blood pressure. However, adolescents classified with high body mass index, waist circumference, and waist to height ratio demonstrated a high association of presenting high blood pressure. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  11. Musical theater and opera singing--why so different? A study of subglottal pressure, voice source, and formant frequency characteristics.

    Science.gov (United States)

    Björkner, Eva

    2008-09-01

    The considerable voice timbre differences between musical theater (MT) and western operatic singers are analyzed with respect to voice source and formant frequencies in five representatives of each singer group. Audio, subglottal pressure (P(sub)), and electroglottograph (EGG) signals were recorded while the subjects sang a sequence of [pae:] syllables starting at maximal vocal loudness and then gradually decreasing vocal loudness. The task was performed at each of two fundamental frequencies (F(0)), approximately one octave apart. Ten equally spaced P(sub) values were then selected for each F(0). The subsequent vowels were analyzed in terms of flow glottograms derived by inverse filtering the audio signal, which also yielded formant frequency data. Period time (T(0)), peak-to-peak pulse amplitude (U(p-t-p)), and maximum flow declination rate (MFDR) were measured from the flow glottograms while closed quotient Q(closed) (T(cl)/T(0)) was determined in combination with the differentiated EGG signal. Also the relationship between the first and the second harmonic in the spectrum (H(1)-H(2)), the amplitude quotient (AQ), that is, the ratio between U(p-t-p) and MFDR, and normalized AQ, that is, AQ normalized with respect to period time was calculated as well as the sound pressure level. The results showed that both the MT and the opera singers varied their P(sub) systematically, approximately doubling P(sub) for a doubling of F(0). For a given value of P(sub), the MT singers produced higher values of MFDR, U(p-t-p), and Q(closed), and lower values of H(1)-H(2), indicating a weaker fundamental. Further, the MT singers showed higher formant frequencies and did not show the opera singers' characteristic clustering of F(3), F(4), and F(5).

  12. Effect of different levels of continuous positive airway pressure on the 99mTc-DTPA lung clearance

    Directory of Open Access Journals (Sweden)

    Dulciane Nunes Paiva

    2014-04-01

    Full Text Available Backgound and Objectives: Positive airway pressure continues (CPAP produces significant hemodynamic changes that may influence the variability of breathing pattern and heart rate, acting as an additional therapy to prevent atelectasis and to combat hypoxia. The rate of inhaled 99 m Technetiumdiethylenetriaminepentaacetic acid (99mTc-DTPA, along with changes in the lung epithelium cause an increase in the rate of clearance of this compound. The aim of this study was evaluate the pulmonary clearance rate of 99mTechnetium Diethylenetriaminepentaacetic acid (99mTc-DTPA through the use of different levels of CPAP. Methods: It was a quasi-experimental study involving 17 healthy individuals with normal lung functional. 99mTc-DTPA, as aerosol, was nebulized for 3 minutes with the individual in a sitting position. The pulmonary clearance rate was assessed through pulmonary scintigraphy under spontaneous breathing and under 20 and 10 cmH2 O CPAP in the sitting position. The clearance rate was expressed as the half-time (T½ that is the time for the activity to decrease to 50% of the peak value. Results: 20 cmH2 O CPAP produced significant reduction of the T½ of 99mTc-DTPA in the sitting position (p=0.005. However, 10 cmH2 O CPAP did not alter the T½ of DTPA in the same positions. Conclusion: High levels of continuos positive pressure in normal lungs resulted in faster 99mTc-DTPA clearance moreover, 10 cmH2 O did not alter its clearance rate. KEYWORDS: Noninvasive ventilation. Technetium Tc 99m Pentetate. Radionuclide Imaging.

  13. Genetic admixture, social-behavioural factors and body composition are associated with blood pressure differently by racial-ethnic group among children.

    Science.gov (United States)

    Klimentidis, Y C; Dulin-Keita, A; Casazza, K; Willig, A L; Allison, D B; Fernandez, J R

    2012-02-01

    Cardiovascular disease has a progressively earlier age of onset, and disproportionately affects African Americans (AAs) in the United States. It has been difficult to establish the extent to which group differences are due to physiological, genetic, social or behavioural factors. In this study, we examined the association between blood pressure and these factors among a sample of 294 children, identified as AA, European American or Hispanic American. We use body composition, behavioural (diet and physical activity) and survey-based measures (socio-economic status and perceived racial discrimination), as well as genetic admixture based on 142 ancestry informative markers (AIMs) to examine associations with systolic and diastolic blood pressure. We find that associations differ by ethnic/racial group. Notably, among AAs, physical activity and perceived racial discrimination, but not African genetic admixture, are associated with blood pressure, while the association between blood pressure and body fat is nearly absent. We find an association between blood pressure and an AIM near a marker identified by a recent genome-wide association study. Our findings shed light on the differences in risk factors for elevated blood pressure among ethnic/racial groups, and the importance of including social and behavioural measures to grasp the full genetic/environmental aetiology of disparities in blood pressure.

  14. Evolution effects of the copper surface morphology on the nucleation density and growth of graphene domains at different growth pressures

    Science.gov (United States)

    Hedayat, Seyed Mahdi; Karimi-Sabet, Javad; Shariaty-Niassar, Mojtaba

    2017-03-01

    In this work, we study the influence of the surface morphology of the catalytic copper substrate on the nucleation density and the growth rate of graphene domains at low and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) processes. In order to obtain a wide range of initial surface morphology, precisely controlled electropolishing methods were developed to manipulate the roughntreess value of the as-received Cu substrate (RMS = 30 nm) to ultra-rough (RMS = 130 nm) and ultra-smooth (RMS = 2 nm) surfaces. The nucleation and growth of graphene domains show obviously different trends at LPCVD and APCVD conditions. In contrast to APCVD condition, the nucleation density of graphene domains is almost equal in substrates with different initial roughness values at LPCVD condition. We show that this is due to the evolution of the surface morphology of the Cu substrate during the graphene growth steps. By stopping the surface sublimation of copper substrate in a confined space saturated with Cu atoms, the evolution of the Cu surface was impeded. This results in the reduction of the nucleation density of graphene domains up to 24 times in the pre-smoothed Cu substrates at LPCVD condition.

  15. Race and Sex Differences of Long-Term Blood Pressure Profiles From Childhood and Adult Hypertension: The Bogalusa Heart Study.

    Science.gov (United States)

    Shen, Wei; Zhang, Tao; Li, Shengxu; Zhang, Huijie; Xi, Bo; Shen, Hongbing; Fernandez, Camilo; Bazzano, Lydia; He, Jiang; Chen, Wei

    2017-07-01

    This study aims to characterize longitudinal blood pressure (BP) trajectories from childhood in black-white and sex groups and examine the association between childhood level-independent trajectories of BP and adult hypertension. The longitudinal cohort consisted of 2732 adults who had body mass index and BP measured 4 to 15 times from childhood (4-19 years) to adulthood (20-51 years). Model-estimated levels and linear slopes of BP and body mass index at childhood age points were calculated at 1-year intervals using the growth curve parameters and their first derivatives, respectively. Linear and nonlinear curve parameters differed significantly between race-sex groups; BP levels showed race and sex differences 15 years of age onward. Hypertensives had higher long-term BP levels than normotensives in race-sex groups. Although linear and nonlinear slope parameters of BP were race and sex specific, they differed consistently, significantly between hypertension and normotension groups. BP trajectories during young adulthood (20-35 years) were significantly greater in hypertensives than in normotensives; however, the trajectories during middle-aged adulthood (36-51 years) were significantly smaller in hypertensives than in normotensives. Level-independent linear slopes of systolic BP showed significantly negative associations (odds ratio=0.50≈0.76; P hypertension, adjusting for covariates. These associations were consistent across race-sex groups. These observations indicate that adult hypertension originates in childhood, with different longitudinal BP trajectory profiles during young and middle-aged adulthood in black-white and sex groups. Puberty is a crucial period for the development of hypertension in later life. © 2017 American Heart Association, Inc.

  16. Cortical response variation with different sound pressure levels: a combined event-related potentials and FMRI study.

    Directory of Open Access Journals (Sweden)

    Irene Neuner

    Full Text Available Simultaneous recording of electroencephalography (EEG and functional magnetic resonance imaging (fMRI provides high spatial and temporal resolution. In this study we combined EEG and fMRI to investigate the structures involved in the processing of different sound pressure levels (SPLs.EEG data were recorded simultaneously with fMRI from 16 healthy volunteers using MR compatible devices at 3 T. Tones with different SPLs were delivered to the volunteers and the N1/P2 amplitudes were included as covariates in the fMRI data analysis in order to compare the structures activated with high and low SPLs. Analysis of variance (ANOVA and ROI analysis were also performed. Additionally, source localisation analysis was performed on the EEG data.The integration of averaged ERP parameters into the fMRI analysis showed an extended map of areas exhibiting covariation with the BOLD signal related to the auditory stimuli. The ANOVA and ROI analyses also revealed additional brain areas other than the primary auditory cortex (PAC which were active with the auditory stimulation at different SPLs. The source localisation analyses showed additional sources apart from the PAC which were active with the high SPLs.The PAC and the insula play an important role in the processing of different SPLs. In the fMRI analysis, additional activation was found in the anterior cingulate cortex, opercular and orbito-frontal cortices with high SPLs. A strong response of the visual cortex was also found with the high SPLs, suggesting the presence of cross-modal effects.

  17. Differences in Activation Area Within Brodmann Area 2 Caused by Pressure Stimuli on Fingers and Joints: In Case of Male Subjects.

    Science.gov (United States)

    Choi, Mi-Hyun; Kim, Hyung-Sik; Baek, Ji-Hye; Lee, Jung-Chul; Park, Sung-Jun; Jeong, Ul-Ho; Gim, Seon-Young; Kim, Sung-Phil; Lim, Dae-Woon; Chung, Soon-Cheol

    2015-09-01

    In this study, a constant pressure stimulus was applied on the 3 joints (first [p1], second [p2], and third [p3] joints) of 4 fingers (index, middle, ring, and little fingers), and the activation areas within Brodmann area 2 (BA 2) were compared for these different fingers and joints by using functional magnetic resonance imaging. Eight healthy male college students (25.4 ± 1.32 years) participated in the study. Each session was composed of 3 blocks, and each block was composed of a Control phase (30 seconds) and a Pressure phase (30 seconds). No pressure stimulus was applied in the Control phase, during which the subjects would simply lay comfortably with their eyes closed. In the Pressure phase, a pressure stimulus was applied onto one of the joints of the selected finger. For each finger and joint, BA 2 areas activated by the pressure stimulus were extracted by the region of interest method. There was a significant difference in the activation areas for the different fingers (P = .042) as well as for the different joints (P = .050). The activation area decreased in the order of the little, index, and middle fingers, as well as in the order of p1, p3, and p2.

  18. Changes of intraocular pressure in different trimesters of pregnancy among Syrian refugees in Turkey: A cross-sectional study.

    Science.gov (United States)

    Tolunay, Harun Egemen; Özcan, Sait Coşkun; Şükür, Yavuz Emre; Özarslan Özcan, Deniz; Adıbelli, Fatih Mehmet; Hilali, Neşe Gül

    2016-06-01

    To evaluate the physiologic changes in intraocular pressure associated with pregnancy in healthy Syrian refugee women in Turkey. In this cross-sectional study, intraocular pressures were measured using a Goldmann tonometer in 235 patients in the first, second, and third trimester of pregnancy and puerperium among Syrian refugees in Turkey. Mean intraocular pressures values of the right eye were 15.5±2.5 mmHg, 14.4±1.4 mmHg, 13.9±1.6 and 14.7±1.9 mmHg in the three trimesters and puerperium, respectively. Mean intraocular pressures values of the left eye were 15.3±1.6 mmHg, 14.3±1.4 mmHg, 13.9±1.6 and 15.3±2.2 mmHg in the three trimesters and puerperium, respectively. The mean intraocular pressures values measured from both eyes were significantly higher in first trimester and puerperal period than in the third trimester (p<0.001). Changes in the intraocular pressure in pregnancy are common and temporary. This study shows the baseline changes in the intraocular pressure during pregnancy in healthy women. Therefore, we cannot extrapolate the results to the whole eye. A decrease in intraocular pressures was shown in healthy pregnant women.

  19. SrRuO3 thin films grown on MgO substrates at different oxygen partial pressures

    KAUST Repository

    Zou, Bin

    2013-01-08

    A comprehensive study of SrRuO3 thin films growth on (001) MgO substrates by pulsed laser deposition in a wide oxygen pressure range from 10 to 300 mTorr was carried out. The experimental results showed a correlation between the lattice constants, resistivity, and oxygen partial pressures used. Ru deficiency detected only in films deposited at lower oxygen pressures (<50 mTorr), resulted in an elongation of the in-plane and out-of-plane lattice constants and an increase in the film resistivity. When deposited with oxygen partial pressure of 50 mTorr, SrRuO3 films had lattice parameters matching those of bulk SrRuO3 material and exhibited room temperature resistivity of 320 μΩ·cm. The resistivity of SrRuO 3/MgO films decreased with increasing oxygen partial pressure. Copyright © 2013 Materials Research Society.

  20. A comparison of ground and satellite observations of cloud cover to saturation pressure differences during a cold air outbreak

    Energy Technology Data Exchange (ETDEWEB)

    Alliss, R.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The role of clouds in the atmospheric general circulation and the global climate is twofold. First, clouds owe their origin to large-scale dynamical forcing, radiative cooling in the atmosphere, and turbulent transfer at the surface. In addition, they provide one of the most important mechanisms for the vertical redistribution of momentum and sensible and latent heat for the large scale, and they influence the coupling between the atmosphere and the surface as well as the radiative and dynamical-hydrological balance. In existing diagnostic cloudiness parameterization schemes, relative humidity is the most frequently used variable for estimating total cloud amount or stratiform cloud amount. However, the prediction of relative humidity in general circulation models (GCMs) is usually poor. Even for the most comprehensive GCMs, the predicted relative humidity may deviate greatly from that observed, as far as the frequency distribution of relative humidity is concerned. Recently, there has been an increased effort to improve the representation of clouds and cloud-radiation feedback in GCMs, but the verification of cloudiness parameterization schemes remains a severe problem because of the lack of observational data sets. In this study, saturation pressure differences (as opposed to relative humidity) and satellite-derived cloud heights and amounts are compared with ground determinations of cloud cover over the Gulf Stream Locale (GSL) during a cold air outbreak.

  1. Three different low-temperature plasma-based methods for hydrophilicity improvement of polyethylene films at atmospheric pressure

    International Nuclear Information System (INIS)

    Chen Guang-Liang; Zheng Xu; Huang Jun; Si Xiao-Lei; Chen Zhi-Li; Xue Fei; Massey Sylvain

    2013-01-01

    Three different low-temperature plasma-based methods were used to improve the surface hydrophilicity of polyethylene (PE) films, and all the modification processes were carried out by employing an atmospheric pressure plasma jet (APPJ) system. (a) PE films were directly modified by APPJ using a gas mixture of He and O 2 . (b) Acrylic acid (AA) was introduced into the system and a polymer acrylic acid (PAA) coating was deposited onto the PE films. (c) AA was grafted onto the PE surface activated by plasma pre-treatment. It was found that the hydrophilicity of the PE films was significantly improved for all the three methods. However, the samples modified by Process (a) showed hydrophobicity recovery after a storage time of 20 days while no significant change was found in samples modified by Process (b) and Process (c). The Fourier transform infrared spectroscopy (FTIR) results indicated that the most intensive C=O peak was detected on the PE surface modified by Process (c). According to the X-ray photoelectron spectroscopy (XPS) analysis, the ratios of oxygen-containing polar groups for samples modified by Process (b) and Process (c) were higher than that modified by Process (a)

  2. Auditory mechanics in a bush-cricket: direct evidence of dual sound inputs in the pressure difference receiver.

    Science.gov (United States)

    Jonsson, Thorin; Montealegre-Z, Fernando; Soulsbury, Carl D; Robson Brown, Kate A; Robert, Daniel

    2016-09-01

    The ear of the bush-cricket, Copiphora gorgonensis, consists of a system of paired eardrums (tympana) on each foreleg. In these insects, the ear is backed by an air-filled tube, the acoustic trachea (AT), which transfers sound from the prothoracic acoustic spiracle to the internal side of the eardrums. Both surfaces of the eardrums of this auditory system are exposed to sound, making it a directionally sensitive pressure difference receiver. A key feature of the AT is its capacity to reduce the velocity of sound propagation and alter the acoustic driving forces at the tympanum. The mechanism responsible for reduction in sound velocity in the AT remains elusive, yet it is deemed to depend on adiabatic or isothermal conditions. To investigate the biophysics of such multiple input ears, we used micro-scanning laser Doppler vibrometry and micro-computed X-ray tomography. We measured the velocity of sound propagation in the AT, the transmission gains across auditory frequencies and the time-resolved mechanical dynamics of the tympanal membranes in C. gorgonensis Tracheal sound transmission generates a gain of approximately 15 dB SPL, and a propagation velocity of ca 255 m s -1 , an approximately 25% reduction from free field propagation. Modelling tracheal acoustic behaviour that accounts for thermal and viscous effects, we conclude that reduction in sound velocity within the AT can be explained, among others, by heat exchange between the sound wave and the tracheal walls. © 2016 The Author(s).

  3. Ionic conductivity ageing investigation of 1Ce10ScSZ in different partial pressures of oxygen

    DEFF Research Database (Denmark)

    Omar, Shobit; Belda, Adriana; Escardino, Agustín

    2011-01-01

    The conductivity and its ageing behaviour has been determined for zirconia co-doped with 10 mol% of Sc2O3 and 1 mol% CeO2 in different partial pressures of oxygen at 600 °C. After 3000 h, samples kept in air, in a humidified mixture of H2/N2 and in humidified H2 exhibited loss in the ionic...... conductivity of 9%, 19% and 25%, respectively. The conductivity degradation rates after the first 1000 h were 1.5%/1000 h in air and 4.3%/1000 h in humidified H2. For all atmospheres, after 3000 h at 600 °C the conductivity value remained above 10 mS/cm, the minimum value required for viable solid oxide fuel...... of the reduction front. The core/shell model was applied on the aged reduced sample, and the conductivity of the reduced region is estimated to be 27% lower than the unaged sample. The conductivity behaviour upon re-oxidation is also investigated in air at 600 °C. The conductivity recovers significantly...

  4. An in vitro study comparing a peripherally inserted central catheter to a conventional central venous catheter: no difference in static and dynamic pressure transmission

    Directory of Open Access Journals (Sweden)

    Gregg Bethene L

    2010-10-01

    Full Text Available Abstract Background Early goal directed therapy improves survival in patients with septic shock. Central venous pressure (CVP monitoring is essential to guide adequate resuscitation. Use of peripherally inserted central catheters (PICC is increasing, but little data exists comparing a PICC to a conventional CVP catheter. We studied the accuracy of a novel PICC to transmit static and dynamic pressures in vitro. Methods We designed a device to generate controlled pressures via a column of water allowing simultaneous measurements from a PICC and a standard triple lumen catheter. Digital transducers were used to obtain all pressure readings. Measurements of static pressures over a physiologic range were recorded using 5Fr and 6Fr dual lumen PICCs. Additionally, random repetitive pressure pulses were applied to the column of water to simulate physiologic intravascular pressure variations. The resultant PICC and control waveforms were recorded simultaneously. Results Six-hundred thirty measurements were made using the 5 Fr and 6 Fr PICCs. The average bias determined by Bland-Altman plot was 0.043 mmHg for 5 Fr PICC and 0.023 mmHg for 6 Fr PICC with a difference range of 1.0 to -1.0. The correlation coefficient for both catheters was 1.0 (p-value Conclusion In vitro, no static or dynamic pressure differences were found between the PICC and a conventional CVP catheter. Clinical studies are required to assess whether the novel PICC has bedside equivalence to conventional catheters when measuring central venous pressures.

  5. The Immediate Effects of Deep Pressure on Young People with Autism and Severe Intellectual Difficulties: Demonstrating Individual Differences

    Directory of Open Access Journals (Sweden)

    Lana Bestbier

    2017-01-01

    Full Text Available Background. Deep pressure is widely used by occupational therapists for people with autism spectrum disorders. There is limited research evaluating deep pressure. Objective. To evaluate the immediate effects of deep pressure on young people with autism and severe intellectual disabilities. Methods. Mood and behaviour were rated for 13 pupils with ASD and severe ID before and after deep pressure sessions. Results. Sufficient data was available from 8 participants to be analysed using Tau-U, a nonparametric technique that allows for serial dependence in data. Six showed benefits statistically. Five of these showed benefits across all domains, and one showed benefits on three out of five domains. Relevance to Clinical Practice. Deep pressure appears to be of immediate benefit to this population with autism and severe ID, but the heterogeneity of response suggests that careful monitoring of response should be used and deep pressure discontinued when it is no longer of benefit. Limitations. This is an open label evaluation study using rating scales. Recommendations for Future Research. Future studies of the use of deep pressure should use physiological response measures, in addition to blinded raters for aspects of behaviours such as attitude to learning psychological health not captured physiologically.

  6. Characterization of Whey Protein Oil-In-Water Emulsions with Different Oil Concentrations Stabilized by Ultra-High Pressure Homogenization

    Directory of Open Access Journals (Sweden)

    Essam Hebishy

    2017-02-01

    Full Text Available In this study, the effect of ultra-high-pressure homogenization (UHPH: 100 or 200 MPa at 25 °C, in comparison to colloid mill (CM: 5000 rpm at 20 °C and conventional homogenization (CH: 15 MPa at 60 °C, on the stability of oil-in-water emulsions with different oil concentrations (10, 30 or 50 g/100 g emulsified by whey protein isolate (4 g/100 g was investigated. Emulsions were characterized for their microstructure, rheological properties, surface protein concentration (SPC, stability to creaming and oxidative stability under light (2000 lux/m2. UHPH produced emulsions containing lipid droplets in the sub-micron range (100–200 nm and with low protein concentrations on droplet surfaces. Droplet size (d3.2, µm was increased in CH and UHPH emulsions by increasing the oil concentration. CM emulsions exhibited Newtonian flow behaviour at all oil concentrations studied; however, the rheological behaviour of CH and UHPH emulsions varied from Newtonian flow (n ≈ 1 to shear-thinning (n ˂ 1 and thixotropic behaviour in emulsions containing 50% oil. This was confirmed by the non-significant differences in the d4.3 (µm value between the top and bottom of emulsions in tubes left at room temperature for nine days and also by a low migration velocity measured with a Turbiscan LAB instrument. UHPH emulsions showed significantly lower oxidation rates during 10 days storage in comparison to CM and CH emulsions as confirmed by hydroperoxides and thiobarbituric acid-reactive substances (TBARS. UHPH emulsions treated at 100 MPa were less oxidized than those treated at 200 MPa. The results from this study suggest that UHPH treatment generates emulsions that have a higher stability to creaming and lipid oxidation compared to colloid mill and conventional treatments.

  7. [Effects of different levels of end-expiratory pressure on hemodynamic, respiratory mechanics and systemic stress response during laparoscopic cholecystectomy].

    Science.gov (United States)

    Sen, Oznur; Erdogan Doventas, Yasemin

    General anesthesia causes reduction of functional residual capacity. And this decrease can lead to atelectasis and intrapulmonary shunting in the lung. In this study we want to evaluate the effects of 5 and 10cmH 2 O PEEP levels on gas exchange, hemodynamic, respiratory mechanics and systemic stress response in laparoscopic cholecystectomy. American Society of Anesthesiologist I-II physical status 43 patients scheduled for laparoscopic cholecystectomy were randomly selected to receive external PEEP of 5cmH 2 O (PEEP 5 group) or 10cmH 2 O PEEP (PEEP 10 group) during pneumoperitoneum. Basal hemodynamic parameters were recorded, and arterial blood gases (ABG) and blood sampling were done for cortisol, insulin and glucose level estimations to assess the systemic stress response before induction of anesthesia. Thirty minutes after the pneumoperitoneum, the respiratory and hemodynamic parameters were recorded again and ABG and sampling for cortisol, insulin, and glucose levels were repeated. Lastly hemodynamic parameters were recorded; ABG analysis and sampling for stress response levels were taken after 60minutes from extubation. There were no statistical differences between the two groups about hemodynamic and respiratory parameters except mean airway pressure (P mean ). P mean , compliance and PaO 2 ; pH values were higher in 'PEEP 10 group'. Also, PaCO 2 values were lower in 'PEEP 10 group'. No differences were observed between insulin and lactic acid levels in the two groups. But postoperative cortisol level was significantly lower in 'PEEP 10 group'. Ventilation with 10cmH 2 O PEEP increases compliance and oxygenation, does not cause hemodynamic and respiratory complications and reduces the postoperative stress response. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  8. Effects of different levels of end-expiratory pressure on hemodynamic, respiratory mechanics and systemic stress response during laparoscopic cholecystectomy.

    Science.gov (United States)

    Sen, Oznur; Erdogan Doventas, Yasemin

    General anesthesia causes reduction of functional residual capacity. And this decrease can lead to atelectasis and intrapulmonary shunting in the lung. In this study we want to evaluate the effects of 5 and 10cmH 2 O PEEP levels on gas exchange, hemodynamic, respiratory mechanics and systemic stress response in laparoscopic cholecystectomy. American Society of Anesthesiologist I-II physical status 43 patients scheduled for laparoscopic cholecystectomy were randomly selected to receive external PEEP of 5cmH 2 O (PEEP 5 group) or 10cmH 2 O PEEP (PEEP 10 group) during pneumoperitoneum. Basal hemodynamic parameters were recorded, and arterial blood gases (ABG) and blood sampling were done for cortisol, insulin and glucose level estimations to assess the systemic stress response before induction of anesthesia. Thirty minutes after the pneumoperitoneum, the respiratory and hemodynamic parameters were recorded again and ABG and sampling for cortisol, insulin, and glucose levels were repeated. Lastly hemodynamic parameters were recorded; ABG analysis and sampling for stress response levels were taken after 60minutes from extubation. There were no statistical differences between the two groups about hemodynamic and respiratory parameters except mean airway pressure (P mean ). P mean , compliance and PaO 2 ; pH values were higher in 'PEEP 10 group'. Also, PaCO 2 values were lower in 'PEEP 10 group'. No differences were observed between insulin and lactic acid levels in the two groups. But postoperative cortisol level was significantly lower in 'PEEP 10 group'. Ventilation with 10cmH 2 O PEEP increases compliance and oxygenation, does not cause hemodynamic and respiratory complications and reduces the postoperative stress response. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  9. A Comparative Study on Energy and Exergy Analyses of a CI Engine Performed with Different Multiple Injection Strategies at Part Load: Effect of Injection Pressure

    Directory of Open Access Journals (Sweden)

    Muammer Özkan

    2015-01-01

    Full Text Available In this study, a four stroke four cylinder direct injection CI engine was run using three different injection pressures. In all measurements, the fuel quantity per cycle, the pre injection and main injection timing, the boost pressure and the engine speed were kept constant. The motor tests were performed under 130, 140 and 150 MPa rail pressure. During the theoretical part of the study, combustion, emission, energy and exergy analysis were made using the test results. An increase in the injection pressure increases combustion efficiency. The results show that combustion efficiency is not enough by itself, because the increase in the power need of the injection pump, decreases the thermal efficiency. The increase in the combustion temperature, increases the cooling loss and decreases the exergetic efficiency. In addition, the NOx emissions increased by 12% and soot emissions decreased 44% via increasing injection pressure by 17%. The thermal and exergetic efficiencies are found inversely proportional with injection pressure. Exergy destruction is found independent of the injection pressure and its value is obtained as ~6%.

  10. Thermodiffusion Coefficient Analysis of n-Dodecane /n-Hexane Mixture at Different Mass Fractions and Pressure Conditions

    Science.gov (United States)

    Lizarraga, Ion; Bou-Ali, M. Mounir; Santamaría, C.

    2018-03-01

    In this study, the thermodiffusion coefficient of n-dodecane/n-hexane binary mixture at 25 ∘C mean temperature was determined for several pressure conditions and mass fractions. The experimental technique used to determine the thermodiffusion coefficient was the thermograviational column of cylindrical configuration. In turn, thermophysical properties, such as density, thermal expansion, mass expansion and dynamic viscosity up to 10 MPa were also determined. The results obtained in this work showed a linear relation between the thermophysical properties and the pressure. Thermodiffusion coefficient values confirm a linear effect when the pressure increases. Additionally, a new correlation based on the thermodiffusion coefficient for n C12/n C6 binary mixture at 25 ∘C temperature for any mass fraction and pressures, which reproduces the data within the experimental error, was proposed.

  11. The difference between the crystallization processes induced by mechanical milling and annealing under normal and high pressure in amorphous Fe-N alloy

    CERN Document Server

    LiuLi; Guo Xing Yuan; Zhao Xu Dong; Yao Bin; Su Wen Hui

    2002-01-01

    An amorphous Fe-N alloy was prepared by ball milling a mixture of Fe and h-BN. Its crystallization processes induced by mechanical milling (MM) and annealing under normal and high pressure were studied. The crystallization product of the amorphous Fe-N alloy induced by MM and annealing at temperatures between 690 and 800 K under pressures of 3-4 GPa is epsilon-Fe sub x N, while the thermal crystallization product under normal pressure is gamma'-Fe sub 4 N. The difference between the crystallization products produced by mechanical and thermal crystallization is attributed to the effects of local pressure and local temperature produced by ball collisions.

  12. Pressure injury progression and factors associated with different end-points in a home palliative care setting: a retrospective chart review study.

    Science.gov (United States)

    Artico, Marco; D'Angelo, Daniela; Piredda, Michela; Petitti, Tommasangelo; Lamarca, Luciano; de Marinis, Maria Grazia; Dante, Angelo; Lusignani, Maura; Matarese, Maria

    2018-03-13

    Patients with advanced illnesses show the highest prevalence for pressure ulcers. In the palliative care setting the ultimate goal is injury healing, but equally important is wound maintenance, wound palliation (wound-related pain and symptom management), and primary and secondary wound prevention. To describe the course of healing for pressure ulcers in a home palliative care setting according to different end-points, and to explore patient and caregiver characteristics and specific care activities associated with their achievement. Four-year retrospective chart review of 669 patients cared for in a home palliative care service, of those 124 (18.5%) patients had at least one pressure ulcer with a survival rate ≤6 months. The proportion of healed pressure ulcers was 24.4%. Of the injuries not healed, 34.0% were in a maintenance phase, while 63.6% were in a process of deterioration. Body Mass Index (p=0.0014), artificial nutrition (p=0.002), and age <70 years (p=0.022) emerged as predictive factors of pressure ulcer complete healing. Artificial nutrition, age, male caregiver (p=0.034) and spouse (p=0.036) were factors significantly associated with a more rapid pressure ulcer healing. Continuous deep sedation was a predictive factor for pressure ulcer deterioration and significantly associated with a more rapid worsening. Pressure ulcer healing is a realistic aim in home palliative care, particularly for injuries not exceeding Stage II occurring at least two weeks before death. When assessing pressure ulcers, our results highlight the need to also pay attention to artificial nutrition, continuous deep sedation, and the caregiver's role and gender. Copyright © 2018. Published by Elsevier Inc.

  13. Investigation of effect of blood pressure and heart rate changes in different positions (lying and sitting on hypotension incidence rate after spinal anesthesia in patients undergoing caesarean section

    Directory of Open Access Journals (Sweden)

    Nahid Manouchehrian

    2016-07-01

    Full Text Available Due to the relatively high prevalence of hypotension (20% -40% after spinal anesthesia as well as the adverse effects of hypotension on mother and baby, it is better to prevent hypotension as much as possible. Therefore, this study is aimed to determine the relationship between postural blood pressure and heart rate changes and hypotension incidence rate after spinal anesthesia in cesarean section.63 women aging18 to 45years old with fullterm pregnancy, who were candidate for caesarean section with spinal anesthesia, entered the study. Afterwards, the diastolic, systolic, and mean arterial pressures as well as the heart rate (pulse in different positions (sitting, lying, and left lateral were measured. After spinal anesthesia, the patients' blood pressure was measured and recorded every minute until the10thmin, then every 3 minute until the15thmin, and then every 5 minute until the end of cesarean section. Data analysis was performed using SPSS (ver. 19 software, descriptive statistics, one-way ANOVA, and post hoc Bonferroni test. In this study, the hypotension incidence rate was 30% and the orthostatic variation rate of the systolic blood pressure in more than half of the people was between 4.39 to 13.49psi, which showed the highest variation compared to the diastolic pressure, mean arterial blood pressure (or: mean arterial pressure [MAP], and heart(pulse. Considering the correlation coefficient of 0.27, the systolic blood pressure in the lateral position has the highest relationship with the incidence of hypotension. The postural systolic blood pressure changes in patients prior to the spinal anesthesia can be a predictive factor for the post-spinal hypotension incidence.

  14. Physical activity and sedentary behaviour at different life stages and adult blood pressure in the 1958 British cohort.

    Science.gov (United States)

    Pouliou, Theodora; Ki, Myung; Law, Catherine; Li, Leah; Power, Chris

    2012-02-01

    To investigate whether physical activity or sedentary behaviour at different life stages is associated with blood pressure (BP) in mid-adulthood; activity levels have accumulative associations with BP; and adult body mass index (BMI) mediates associations. Information on activity and television-viewing was available at several ages (23, 33, 42, 45 years) and BP at 45 years for the 1958 British birth cohort (n = 9927). Associations were examined with and without adjustment for covariates. Active adults, generally, had lower mean systolic and diastolic BP and risk of hypertension than nonactive, although varying by age. After adjustment for covariates, systolic and diastolic BP for active men at 23 years or at 45 years were 1-2 mmHg lower; similar associations were seen for women active at 33 years. Some but not all associations attenuated with further adjustment for BMI: odds ratio (OR) for hypertension associated with 23 years activity changed from 0.82 [95% confidence interval (CI) 0.74, 0.91] to 0.79 (0.70, 0.90) after BMI adjustment. Independent associations of activity at more than one age were found, such that prevalence of hypertension was higher in men active at 23 years but not at 45 years, than men sustaining activity (39 vs. 31%). Sitting at work was unrelated to BP, but there was a trend of higher BP with greater television-viewing: for example risk of hypertension was higher by 10-12% per h/day television-viewing at 45 years after adjustment for covariates, attenuating after allowance for BMI. Our study suggests that there are benefits to BP of becoming and sustaining active lifestyles and minimizing television-viewing over many years of adulthood, with a mediating role for BMI.

  15. Sex differences in the association of childhood socioeconomic status with adult blood pressure change: the CARDIA study.

    Science.gov (United States)

    Janicki-Deverts, Denise; Cohen, Sheldon; Matthews, Karen A; Jacobs, David R

    2012-09-01

    To examine sex differences in the relation of childhood socioeconomic status (CSES) to systolic (SBP) and diastolic blood pressure (DBP) trajectories during 15 years, spanning young (mean [M] [standard deviation {SD}] = 30 [3] years) and middle (M [SD] = 45 [3] years) adulthood, independent of adult SES. A total of 4077 adult participants reported father's and mother's educational attainments at study enrollment (Year 0) and own educational attainment at enrollment and at all follow-up examinations. Resting BP also was measured at all examinations. Data from examination Years 5 (when participant M [SD] age = 30 [3] years), 7, 10, 15, and 20 are examined here. Associations of own adult (Year 5), mother's, and father's educations with 15-year BP trajectories were examined in separate multilevel models. Fully controlled models included time-invariant covariates (age, sex, race, recruitment center) and time-varying covariates that were measured at each examination (marital status, body mass, cholesterol, oral contraceptives/hormones, and antihypertensive drugs). Analyses of parental education controlled for own education. When examined without covariates, higher education - own (SBP γ = -0.03, DBP γ = -0.03), mother's (SBP γ = -0.02, DBP γ = -0.02), and father's (SBP γ = -0.02, DBP γ = -0.01) - were associated with attenuated 15-year increases in BP (p parent's) education with BP trajectories remained independent of standard controls. Sex moderated the apparent null effects of parental education, such that higher parental education-especially mother's, predicted attenuated BP trajectories independent of standard covariates among women (SBP γ = -0.02, p = .02; DBP γ = -0.01, p = .04) but not men (SBP γ = 0.02, p = .06; DBP γ = 0.005, p = .47; p interaction SBP < .001, p interaction DBP = .01). Childhood socioeconomic status may influence women's health independent of their own adult status.

  16. The association between serum uric acid and blood pressure in different age groups in a healthy Chinese cohort.

    Science.gov (United States)

    Cheng, Wenjuan; Wen, Shiling; Wang, Yutang; Qian, Zhiping; Tan, Yuyao; Li, Hongying; Hou, Yueli; Hu, Haiyang; Golledge, Jonathan; Yang, Guang

    2017-12-01

    High serum uric acid (sUA) has been reported to be a risk factor for hypertension however, whether this is the case for all age groups is not clear. We examined the association between sUA concentrations and systolic and diastolic blood pressure (SBP and DBP) in different age groups in a cohort of healthy Chinese participants.A total of 1082 healthy participants aged from 41 to 70 years were included. sUA concentration was measured by the uricase-peroxidase method. SBP and DBP were assessed using mercury sphygmomanometry. Hypertension was defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Hyperuricemia (HUA) was defined as sUA concentration of >7 mg/dL in men and >6 mg/dL in women. The association between sUA concentration and SBP and DBP was examined using Pearson's correlation test, multivariate linear regression, and logistic regression analysis.The prevalence of hypertension and HUA increased with age (P age, sex, total cholesterol, estimated glomerular filtration rate, and fasting plasma glucose). HUA was also a risk factor for hypertension in this age group (odds ratio 1.425, 95% confidence interval, 1.217-1.668, P age groups.In this population of healthy Chinese participants, sUA concentration was positively associated with hypertension only in the 41- to 50-year-old group. Lowering uric acid in this age group may help to reduce the incidence of hypertension. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  17. Determinants of the Morning-Evening Home Blood Pressure Difference in Treated Hypertensives: The HIBA-Home Study

    Directory of Open Access Journals (Sweden)

    Lucas S. Aparicio

    2014-01-01

    Full Text Available Background. The morning home blood pressure (BP rise is a significant asymptomatic target organ damage predictor in hypertensives. Our aim was to evaluate determinants of home-based morning-evening difference (MEdiff in Argentine patients. Methods. Treated hypertensive patients aged ≥18 years participated in a cross-sectional study, after performing home morning and evening BP measurement. MEdiff was morning minus evening home average results. Variables identified as relevant predictors were entered into a multivariable linear regression analysis model. Results. Three hundred sixty-seven medicated hypertensives were included. Mean age was 66.2 (14.5, BMI 28.1 (4.5, total cholesterol 4.89 (1.0 mmol/L, 65.9% women, 11.7% smokers, and 10.6% diabetics. Mean MEdiff was 1.1 (12.5 mmHg systolic and 2.3 (6.1 mmHg diastolic, respectively. Mean self-recorded BP was 131.5 (14.1 mmHg systolic and 73.8 (7.6 mmHg diastolic, respectively. Mean morning and evening home BPs were 133.1 (16.5 versus 132 (15.7 systolic and 75.8 (8.4 versus 73.5 (8.2 diastolic, respectively. Significant beta-coefficient values were found in systolic MEdiff for age and smoking and in diastolic MEdiff for age, smoking, total cholesterol, and calcium-channel blockers. Conclusions. In a cohort of Argentine medicated patients, older age, smoking, total cholesterol, and use of calcium channel blockers were independent determinants of home-based MEdiff.

  18. Self-Recruitment in the Bumphead Parrotfish Under Different Levels of Fishing Pressure in the Solomon Islands

    KAUST Repository

    Lozano-Cortés, Diego

    2014-12-01

    Knowledge in the spatial patterns of fish larval dispersal is crucial for the establishment of a sustainable management of fisheries and species conservation. Direct quantification of larval dispersal is a challenging task due to the difficulty associated with larval tracking in the vast ocean. However, genetic approaches can be used to estimate it. Here, I employed genetic markers (microsatellites) as a proxy to determine dispersal patterns and self-recruitment levels using parentage analysis in the bumphead parrotfish (Bolbometapon muricatum) in the Solomon Islands. Tissue samples of 3924 fish (1692 juveniles, 1121 males and 1111 females) were collected from a spear-fishery at the Kia District in Santa Isabel Island. The samples come from three distinct zones with different fishing pressure histories (lightly fished, recently fished, and heavily fished). The mean dispersal distance estimated for the bumphead parrotfish was 36.5 Km (range 4 – 78 Km) and the genetic diversity for the population studied was low in comparison with other reef fishes. The parentage analysis identified 68 parent–offspring relationships, which represents a self-recruitment level of almost 50 %. Most of the recruits were produced in the zone that recently started to be fished and most of these recruits dispersed to the heavily fished zone. Comparisons of genetic diversity and relatedness among adults and juveniles suggested the potential occurrence of sweepstakes reproductive success. These results suggest that management measures must be taken straightaway to assure the sustainability of the spear-fishery. These measures may imply the ban on juveniles fishing in the heavily fished zone and the larger adults in the recently fished zone. Overall, the population dynamics of the studied system seem to be strongly shaped by self-recruitment and sweepstakes reproduction events.

  19. Experimental and simulation determination of minimum miscibility pressure for a Bakken tight oil and different injection gases

    Directory of Open Access Journals (Sweden)

    Sheng Li

    2017-03-01

    Full Text Available The effective development of unconventional tight oil formations, such as Bakken, could include CO2 enhanced oil recovery (EOR technologies with associated benefits of capturing and storing large quantities of CO2. It is important to conduct the gas injection at miscible condition so as to reach maximum recovery efficiency. Therefore, determination of the minimum miscibility pressure (MMP of reservoir live oil–injection gas system is critical in a miscible gas flooding project design. In this work, five candidate injection gases, namely CO2, CO2-enriched flue gas, natural gas, nitrogen, and CO2-enriched natural gas, were selected and their MMPs with a Bakken live oil were determined experimentally and numerically. At first, phase behaviour tests were conducted for the reconstituted Bakken live oil and the gases. CO2 outperformed other gases in terms of viscosity reduction and oil swelling. Rising bubble apparatus (RBA determined live oil–CO2 MMP as 11.9 MPa and all other gases higher than 30 MPa. The measured phase behaviour data were used to build and tune an equation-of-state (EOS model, which calculated the MMPs for different live oil-gas systems. The EOS-based calculations indicated that CO2 had the lowest MMP with live oil among the five gases in the study. At last, the commonly-accepted Alston et al. equation was used to calculate live oil–pure CO2 MMP and effect of impurities in the gas phase on MMP change. The Bakken oil–CO2 had a calculated MMP of 10.3 MPa from the Alston equation, and sensitivity analysis showed that slight addition of volatile impurities, particularly N2, can increase MMP significantly.

  20. Role of different negative pressure values in the process of infected wounds treated by vacuum-assisted closure: an experimental study.

    Science.gov (United States)

    Zhou, Min; Yu, Aixi; Wu, Gang; Xia, Chengyan; Hu, Xiang; Qi, Baiwen

    2013-10-01

    Vacuum-assisted closure (VAC) device is widely used to treat infected wounds in clinical work. Although the effect of VAC with different negative pressure values is well established, whether different negative pressures could result in varying modulation of wound relative cytokines was not clear. We hypothesise that instead of the highest negative pressure value the suitable value for VAC is the one which is the most effective on regulating wound relative cytokines. Infected wounds created on pigs' back were used to investigate the effects of varying negative pressure values of VAC devices. Wounds were treated with VAC of different negative pressure values or moist gauze, which was set as control. The VAC foam, semiocclusive dresses and moist gauze were changed on days 3, 5, 7 and 9 after wounds were created. When changing dressings, tissues from wounds were harvested for bacteria count and histology examination including Masson's trichrome stain and immunohistochemistry for microvessels. Western blot was carried out to test the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Results showed that on days 3 and 5 the number of bacteria in wounds treated by VAC with 75, 150, 225 and 300 mmHg was significantly decreased compared with that in wounds treated by gauze and 0 mmHg pressure value. However, there was no difference in wounds treated with negative pressure values of 75 , 150, 225 and 300 mmHg at any time spot. Immunohistochemistry showed that more microvessels were generated in wounds treated by VAC using 75 and 150 mmHg negative pressure comparing with that using 225 and 300 mmHg on days 3 and 5. However this difference vanished on days 7 and 9. Morphological evaluation by Masson's trichrome staining showed increased collagen deposition in VAC of 75 and 150 mmHg compared with that in VAC of 225 and 300 mmHg. Western blot showed that the expression of VEGF and bFGF significantly increased when the wounds

  1. The randomized crossover comparison of airway sealing with the laryngeal mask airway Supreme(™) at three different intracuff pressures in children.

    Science.gov (United States)

    Choi, Kwan-Woong; Lee, Jeong-Rim; Oh, Jung-Tak; Kim, Dong Wook; Kim, Min-Soo

    2014-10-01

    An intracuff pressure of 80 cm H2 O in the adult-sized laryngeal mask airway Supreme has been recommended to obtain a higher oropharyngeal leak pressure (OLP). However, the intracuff pressure for the higher OLP in the pediatric laryngeal mask airway Supreme could be different from that in the adult-sized laryngeal mask airway Supreme. Thus, we measured and compared OLP at three intracuff pressures of 40, 60, and 80 cm H2 O in the pediatric laryngeal mask airway Supreme. This study was designed as a randomized crossover study and enrolled 36 children, aged 0-108 months and 5-30 kg in weight. After insertion of the laryngeal mask airway Supreme, oropharyngeal leak pressure (OLP) was measured at intracuff pressures of 40, 60, and 80 cm H2 O according to one of six sequences produced on the basis of 3 × 6 Williams crossover design. During the intraoperative period, the laryngeal mask airway Supreme was maintained using the last intracuff pressure of the allocated sequence. The intraoperative and postoperative complications were compared among three maintenance intracuff pressures. OLP at the intracuff pressure of 60 cm H2 O was significantly higher than that of 40 cm H2 O (17.9 ± 3.9 vs 16.9 ± 4.2 cm H2 O, P = 0.004) and was comparable with that of 80 cm H2 O (17.9 ± 3.9 vs 17.8 ± 4.6 cm H2 O, P = 0.938). There were no significant differences of intraoperative and postoperative complications among the three maintenance intracuff pressures. Our results suggest that the use of an intracuff pressure of 60 cm H2 O in pediatric laryngeal mask airway Supreme provides a higher OLP compared with 40 cm H2 O. © 2014 John Wiley & Sons Ltd.

  2. Analysis of two different types of hydrogen combustion during severe accidents in a typical pressurized water reactor

    International Nuclear Information System (INIS)

    Ko Yuchih; Lee Min

    2005-01-01

    Hydrogen combustion is an important phenomenon that may occur during severe accidents of Nuclear Power Plants (NPPs). Depending on the specific plant design, the initiating events, and mitigation actions executed, hydrogen combustion may have distinct characteristics and may damage the plant in various degrees. The worst scenario will be the catastrophic failure of containment. In this study two specific types of hydrogen combustion are analyzed to evaluate their impact on the containment integrity. In this paper, Station Blackout (SBO) and Loss of Coolant Accidents (LOCAs) sequences are analyzed using MAAP4 (Modular Accident Analysis Program) code. The former sequence is used to represent hydrogen combustion phenomenon under the condition that the reactor pressure vessel (RPV) breaches at high pressure and the latter sequence represents the phenomenon that RPV fails at low pressure. Two types of hydrogen combustion are observed in the simulation. The Type I hydrogen combustion represents global and instantaneous hydrogen combustion. Large pressure spike is created during the combustion and represents a threat to containment integrity. Type II hydrogen combustion is localized burn and burn continuously over a time period. There is hardly any impact of this type hydrogen burn on the containment pressurization rate. Both types of hydrogen combustion can occur in the severe accidents without any human intervention. From the accident mitigation point of view, operators should try to bring the containment into conditions that favor the Type II hydrogen combustion. (authors)

  3. Research on the internal pressure behavior of metal gas distribution pipelines with different types of tubing defects

    Directory of Open Access Journals (Sweden)

    Filip Stefan Mihai

    2017-01-01

    Full Text Available The paper aims to approach an important subject related to natural gas distribution networks which, depending on the expansion of the localities, are composed of intercommunicating pipes, pressure reducing stations and branch connections fittings. The urban networks are the most complex ones and the rural areas networks are the simplest. However, irrespective of their installation, they must meet the safety operating requirements as much as possible. According to standards, all these components must be tight and pressure resistant. In this regard, we intend to approach a very important issue related to the behavior of the tubular steel material showing corrosion and/or material defects, and to the internal stress caused by the gas pressure on the walls of the tubing material.

  4. The vibration and buckling of freely supported non-homogeneous orthotropic conical shells subjected to different uniform pressures

    Energy Technology Data Exchange (ETDEWEB)

    Sofiyev, A.H. [Department of Civil Engineering, Suleyman Demirel University, 32260 Isparta (Turkey)], E-mail: asofiyev@mmf.sdu.edu.tr; Korkmaz, K.A. [Department of Civil Engineering, Suleyman Demirel University, 32260 Isparta (Turkey); Mammadov, Z. [Department of Civil Engineering, Harran University, Sanliurfa (Turkey); Kamanli, M. [Department of Civil Engineering, Selcuk University, Konya (Turkey)

    2009-10-15

    The paper examines the vibration and stability of freely supported orthotropic truncated and complete conical shells with non-homogeneous material properties under uniform lateral and hydrostatic pressures. First, the basic relations have been obtained for orthotropic truncated conical shells, Young's moduli and density which vary continuously in the thickness direction. By applying the Galerkin method, the buckling pressures and lowest cyclic frequencies of truncated and complete conical shells are obtained. To verify the accuracy of the results, comparisons are made with results available in the open literature. This study also examines in detail the effects of the variations of conical shell characteristics, the effects of the non-homogeneity and the orthotropy on the critical pressures and lowest cyclic frequencies of truncated and complete conical shells.

  5. Shallow donor impurities in different shaped double quantum wells under the hydrostatic pressure and applied electric field

    International Nuclear Information System (INIS)

    Kasapoglu, E.; Sari, H.; Sokmen, I.

    2005-01-01

    The combined electric field and hydrostatic pressure effects on the binding energy of the donor impurity in double triangle quantum well (DTQW), double graded (DGQW) and double square (DSQW) GaAs-(Ga,Al)As quantum wells are calculated by using a variational technique within the effective-mass approximation. The results have been obtained in the presence of an electric field applied along the growth direction as a function of hydrostatic pressure, the impurity position, barrier width and the geometric shape of the double quantum wells

  6. Co-gasification of different rank coals with biomass and petroleum coke in a high-pressure reactor for H(2)-rich gas production.

    Science.gov (United States)

    Fermoso, J; Arias, B; Gil, M V; Plaza, M G; Pevida, C; Pis, J J; Rubiera, F

    2010-05-01

    Four coals of different rank were gasified, using a steam/oxygen mixture as gasifying agent, at atmospheric and elevated pressure in a fixed bed reactor fitted with a solids feeding system in continuous mode. Independently of coal rank, an increase in gasification pressure led to a decrease in H(2) + CO production and carbon conversion. Gasification of the different rank coals revealed that the higher the carbon content and reactivity, the greater the hydrogen production. Co-gasification experiments of binary (coal-biomass) and ternary blends (coal-petcoke-biomass) were conducted at high pressure to study possible synergetic effects. Interactions between the blend components were found to modify the gas production. An improvement in hydrogen production and cold gas efficiency was achieved when the coal was gasified with biomass. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Skin perfusion pressure measured by isotope washout in legs with arterial occlusive disease. Evaluation of different tracers, comparison to segmental systolic pressure, angiography and transcutaneous oxygen tension and variations during changes in systemic blood pressure

    DEFF Research Database (Denmark)

    Holstein, P; Trap-Jensen, J; Bagger, H

    1983-01-01

    ), 131I- -antipyrine (131I- -a.p.) was compared to Na(131I-) and 99Tcm-pertechnetate (99Tcm). The average SPP by 131I- -a.p. and by 131I- were approximately equal, 57.0 mmHg (range 18-93) compared to 56.3 mmHg (range 13-88) (P greater than 0.1). The average SPP by 99Tcm was just slightly higher, 60.3 mm...... that 99Tcm is as suitable as the 131I- -labelled tracers in estimating the SPP. The SPP is significantly correlated to skin blood flow, to systolic blood pressure, to tc pO2 and to angiographic findings. Correction of SPP for systemic blood pressure changes can be made in proportion with the measured...

  8. Effect of different methods of accounting for antihypertensive treatment when assessing the relationship between diabetes or obesity and systolic blood pressure.

    Science.gov (United States)

    Tanamas, Stephanie K; Hanson, Robert L; Nelson, Robert G; Knowler, William C

    2017-04-01

    Underlying blood pressure is that observed in the absence of antihypertensive treatment or, among those treated, the estimate of that which would be observed without treatment. This study aims to examine the relationships between diabetes or obesity and underlying systolic blood pressure adjusted for antihypertensive treatment by several methods. Data from two population studies were analyzed-an American Indian community in Arizona and the National Health and Nutrition Examination Surveys. Antihypertensive treatment was accounted for using: no adjustment; antihypertensive use as a covariate; blood pressure dichotomized into normotension and hypertension; addition of a fixed treatment effect; non-parametric algorithm; and censored normal regression. The magnitude of association at each time point differed by adjustment method particularly where there was a difference in prevalence of antihypertensive use between people with and without diabetes or obesity. The common methods of ignoring antihypertensive treatment or including it as a covariate in a regression model underestimated the effects of diabetes and obesity on underlying blood pressure, compared to the recommended method of the censored normal regression. Proper accounting for antihypertensive treatment is needed in interpreting variables that affect blood pressure. Published by Elsevier Inc.

  9. Lack of difference between nebivolol/hydrochlorothiazide and metoprolol/hydrochlorothiazide on aortic wave augmentation and central blood pressure

    NARCIS (Netherlands)

    Eeftinck Schattenkerk, Daan W.; van den Bogaard, Bas; Cammenga, Marianne; Westerhof, Berend E.; Stroes, Erik S. G.; van den Born, Bert-Jan H.

    2013-01-01

    The vasodilating beta-blocker nebivolol is thought to be superior in lowering wave reflection and central blood pressure (BP) compared to nonvasodilating beta-blockers. The results from studies comparing nebivolol with either metoprolol or atenolol, with or without hydrochlorothiazide (HCTZ), are

  10. Progressive and cumulative fabric effects of multiple hydroentangling impacts at different water pressures on greige cotton substrate

    Science.gov (United States)

    A practical study was conducted to determine the effects of the hydroentangling jet strip’s orifice size and the hydroentangling water pressure on the energy expended and the properties of the resulting nonwoven fabrics produced on a commercial-grade hydro-entanglement (HE) system, using greige cott...

  11. Differing Pattern of Ambulatory Blood Pressure in Very Elderly Men Expresses Dynamics in Atherosclerotic Load in the Senescence

    Directory of Open Access Journals (Sweden)

    Arkadiusz Siennicki-Lantz

    2012-01-01

    Full Text Available To assess an impact of vascular risk factors on ambulatory blood pressure measurement (ABPM in the elderly, we followed up a population-based cohort of men from 68 until 82 years, when 104 survivors underwent ABPM. Results. At age 68, hypertension and high clinic blood pressure (CBP did not predict ABPM level. Smoking and low ankle-brachial index (ABI predicted higher ABPM variability and pulse pressure (PP, but not absolute ABPM values. At age 82, hypertension, high or increasing CBP, strongly positively correlated with all variables of ABPM. Carotid stenosis, low or declining ABI during followup, correlated with higher nocturnal ABPM and PP. Concluding. Hypertension and vascular risk factors in a cohort of 68-year-old men do not result in higher ABPM at age 82, possibly due to inflection point in their pressure development. Higher ABPM reflects instead an increasing CBP and aggravating atherosclerosis during the preceding decade in that part of the cohort with previously favorable risk factor status.

  12. Differences in Blood Pressure in Infants after General Anesthesia Compared to Awake Regional Anesthesia (GAS Study - A Prospective Randomized Trial)

    NARCIS (Netherlands)

    McCANN, M.E.; Withington, Davinia E.; Arnup, Sarah J.; Davidson, Andrew J.; DISMA, N.; FRAWLEY, G.; Morton, Neil S.; BELL, G.; Hunt, Rodney W.; Bellinger, David C; Polaner, D. M.; Leo-Macias, Alejandra; Absalom, Anthony R.; Von Ungern-Sternberg, Britta S.; Izzo, Francesca; Szmuk, Peter; Young, Vanessa; Soriano, S. G.; De Graaff, J. C.|info:eu-repo/dai/nl/249966271

    2017-01-01

    BACKGROUND: The General Anesthesia compared to Spinal anesthesia (GAS) study is a prospective randomized, controlled, multisite, trial designed to assess the influence of general anesthesia (GA) on neurodevelopment at 5 years of age. A secondary aim obtained from the blood pressure data of the GAS

  13. Does the pulse pressure in people of European, African and South Asian descent differ? A systematic review and meta-analysis of UK data

    NARCIS (Netherlands)

    Agyemang, C.; Bhopal, R.; Redekop, W. K.

    2007-01-01

    The aim of this study was to assess whether the pulse pressures (PPs) in people of African and South Asian descent differ from those of the European-origin White (henceforth, White) in the UK. A systematic literature review was carried out using MEDLINE 1966-2006 and EMBASE 1980-2006. The

  14. [Influence of different inner dressings in negative-pressure wound therapy on escharectomy wound of full-thickness burn rabbits].

    Science.gov (United States)

    Lin, J H; Chen, J; Xue, D J; Huang, W X; Su, G L

    2017-07-20

    Objective: To explore the influence of different inner dressings in negative-pressure wound therapy (NPWT) on escharectomy wound of full-thickness burn rabbits. Methods: Eighteen Japanese white rabbits were inflicted with full-thickness burn on unilateral back. They were divided into polymer dressing group (PD), biological dressing group (BD), and silver biological dressing group (SBD), according to the random number table, with 6 rabbits in each group. On 3 days post burn, the wounds were performed with escharectomy, and then wounds of rabbits in group PD were covered with polyurethane foam. Wounds of rabbits in group BD were covered with porcine acellular dermal matrix (ADM) and wounds of rabbits in group SBD were covered with silver porcine ADM. Then continuous NPWT was performed on rabbits of the three groups for 7 days. Immediately after surgery and on post surgery day (PSD) 7, general observation of wound was conducted and tissue around the wound was harvested for determination of dry to wet weight ratio. The content of bacteria was counted and the content of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 in wound was determined by enzyme-linked immunosorbent assay. Fibroblasts in wound were counted after Masson staining and number of microvessels was counted after CD31 antibody immunohistochemical staining. Data were processed with analysis of variance for repeated measurement, LSD- t test, paired samples t test, and Bonferroni correction. Results: (1) Immediately after surgery, there was no granulation tissue in basal wound of rabbits in the three groups, with rich blood supply and obvious edema. On PSD 7, much granulation tissue was found in basal wound of rabbits in the three groups, with no or mild edema and no obvious redness and swelling in wound edge. (2) There were no significant differences in dry to wet weight ratios of tissue around the wound among and within the three groups immediately after surgery and on PSD 7 (with F

  15. Simulation of a scenario of total loss of external and internal power (Sbo) for different vent pressures of the containment of a BWR-5

    International Nuclear Information System (INIS)

    Cardenas V, J.; Mugica R, C. A.; Godinez S, V.

    2014-10-01

    The simulation of a Station Black Out (Sbo) was realized with intervention of the vent containment by means of a rigid vent coming from the dry-well and that discharges directly to the atmosphere, with the MELCOR code version 2.1. This scenario was carried out for a BWR-5 and containment type Mark II, with a thermal power of 2317 MWt similar to the reactor of nuclear power plant of Laguna Verde. For this scenario was considered as only available system for coolant injection to the reactor to the Reactor Core Isolation Cooling (Rcic), which remained operating 4 hours with batteries bank. The Security and Relief Valves (SR V) were considered functional (by simplicity) and that they mechanically do not exceed their capacity to liberate pressure due to the performances in their safety way. The operator maneuver to perform the SR V and to de pressurize the vessel until the pressure (13 kg/cm 2 ) to operate the low pressure systems was modeled. The results cover approximately 48 hours (172000 seconds), time in which was observed the behavior of the level and pressure in the vessel. Also the scenario evolution was analyzed to different vent pressures of the primary containment (2.0, 3.0, 4.5, 6.0, and 10.0 kg/cm 2 ), the temperature profiles of the dry-well, the hydrogen accumulation in the containment, the radio-nuclides liberation through rigid vent to the atmosphere and the inventory of these. In this work an analysis of the pressure behavior in the primary containment is presented, with the purpose of minimizing liberated fission products to the environment. (Author)

  16. Microstructure and Electrical Properties of Antimony Telluride Thin Films Deposited by RF Magnetron Sputtering on Flexible Substrate Using Different Sputtering Pressures

    Science.gov (United States)

    Khumtong, T.; Sukwisute, P.; Sakulkalavek, A.; Sakdanuphab, R.

    2017-05-01

    The microstructural, electrical, and thermoelectric properties of antimony telluride (Sb2Te3) thin films have been investigated for thermoelectric applications. Sb2Te3 thin films were deposited on flexible substrate (polyimide) by radiofrequency (RF) magnetron sputtering from a Sb2Te3 target using different sputtering pressures in the range from 4 × 10-3 mbar to 1.2 × 10-2 mbar. The crystal structure, [Sb]:[Te] ratio, and electrical and thermoelectric properties of the films were analyzed by grazing-incidence x-ray diffraction (XRD) analysis, energy-dispersive x-ray spectroscopy (EDS), and Hall effect and Seebeck measurements, respectively. The XRD spectra of the films demonstrated polycrystalline structure with preferred orientation of (015), (110), and (1010). A high-intensity spectrum was found for the film deposited at lower sputtering pressure. EDS analysis of the films revealed the effects of the sputtering pressure on the [Sb]:[Te] atomic ratio, with nearly stoichiometric films being obtained at higher sputtering pressure. The stoichiometric Sb2Te3 films showed p-type characteristics with electrical conductivity, carrier concentration, and mobility of 35.7 S cm-1, 6.38 × 1019 cm-3, and 3.67 cm2 V-1 s-1, respectively. The maximum power factor of 1.07 × 10-4 W m-1 K-2 was achieved for the film deposited at sputtering pressure of 1.0 × 10-2 mbar.

  17. Phase behaviour of pseudo-binary systems of pressurized ((propane + L,L-lactide)) at different ethanol to L,L-lactide mole ratios

    International Nuclear Information System (INIS)

    Bender, João P.; Tres, Marcus V.; Corazza, Marcos L.; Ferreira, Sandra R.S.; Oliveira, J. Vladimir

    2014-01-01

    Highlights: • Phase equilibrium data of (propane + L,L-lactide) system at different ethanol to monomer mole ratios. • Static synthetic method from (323 to 353) K and pressures up to 3.3 MPa. • (Vapour + liquid) (VLE) was observed with bubble point (BP) type transitions. • Experimental modelled using the Peng–Robinson (PR) equation with the Wong–Sandler (PR–WS) rule. - Abstract: This work reports phase equilibrium data of pressurized (propane + L,L-lactide) system at different ethanol to monomer mole ratios (9:1; 7:1; 5:1). Phase equilibrium experiments were accomplished in a high-pressure variable-volume view cell employing the static synthetic method. (Vapour + liquid) equilibrium data for the pseudo-binary systems were determined within the temperature range from (323 to 353) K and pressures up to 3.3 MPa. For the systems investigated, (vapour + liquid) equilibrium (VLE) was visually recorded. It was observed that an increase in temperature or in propane concentration led to a pronounced rise in pressure transition values. On the other hand, an increase in the ethanol to L,L-lactide mole ratio led to a reduction in pressure transitions, whereas a reduction in ethanol concentration complicates the achievement of one-phase homogeneous system. Thus, rapid complete miscibility of the system can be controlled by the amount of ethanol added as a co-solvent. The experimental results were modelled using the Peng–Robinson (PR) equation of state with the Wong–Sandler (PR–WS) mixing rule, providing a good representation of the experimental phase transition points

  18. Who is at higher risk of hypertension? Socioeconomic status differences in blood pressure among Polish adolescents: a population-based ADOPOLNOR study.

    Science.gov (United States)

    Kaczmarek, Maria; Stawińska-Witoszyńska, Barbara; Krzyżaniak, Alicja; Krzywińska-Wiewiorowska, Małgorzata; Siwińska, Aldona

    2015-11-01

    In Poland, there is no data on parental socioeconomic status (SES) as a potent risk factor in adolescent elevated blood pressure, although social differences in somatic growth and maturation of children and adolescents have been recorded since the 1980s. This study aimed to evaluate the association between parental SES and blood pressure levels of their adolescent offspring. A cross-sectional survey was carried out between 2009 and 2010 on a sample of 4941 students (2451 boys and 2490 girls) aged 10-18, participants in the ADOPOLNOR study. The depended outcome variable was the level of blood pressure (optimal, pre- and hypertension) and explanatory variables included place of residence and indicators of parental SES: family size, parental educational attainments and occupation status, income adequacy and family wealth. The final selected model of the multiple multinomial logistic regression analysis (MLRA) with backward elimination procedure revealed the multifactorial dependency of blood pressure levels on maternal educational attainment, paternal occupation and income adequacy interrelated to urbanization category of the place of residence after controlling for family history of hypertension, an adolescent's sex, age and weight status. Consistent rural-to-urban and socioeconomic gradients were found in prevalence of elevated blood pressure, which increased with continuous lines from large cities through small- to medium-sized cities to villages and from high-SES to low-SES familial environments. The adjusted likelihood of developing systolic and diastolic hypertension decreased with each step increase in maternal educational attainment and increased urbanization category. The likelihood of developing prehypertension decreased with increased urbanization category, maternal education, paternal employment status and income adequacy. Weight status appeared to be the strongest confounder of adolescent blood pressure level and, at the same time, a mediator between

  19. Measurement of ion beam angular distribution at different helium gas pressures in a plasma focus device by large-area polycarbonate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohrabi, M.; Habibi, M., E-mail: mortezahabibi@gmail.com; Ramezani, V. [Amirkabir University of Technology, Energy Engineering and Physics Department (Iran, Islamic Republic of)

    2017-02-15

    The paper presents an experimental study and analysis of full helium ion density angular distributions in a 4-kJ plasma focus device (PFD) at pressures of 10, 15, 25, and 30 mbar using large-area polycarbonate track detectors (PCTDs) (15-cm etchable diameter) processed by 50-Hz-HV electrochemical etching (ECE). Helium ion track distributions at different pressures, in particular, at the main axis of the PFD are presented. Maximum ion track density of ~4.4 × 10{sup 4} tracks/cm{sup 2} was obtained in the PCTD placed 6 cm from the anode. The ion distributions for all pressures applied are ring-shaped, which is possibly due to the hollow cylindrical copper anode used. The large-area PCTD processed by ECE proves, at the present state-of-theart, a superior method for direct observation and analysis of ion distributions at a glance with minimum efforts and time. Some observations of the ion density distributions at different pressures are reported and discussed.

  20. Differences in respiratory pressure and pulmonary function among children with spastic diplegic and hemiplegic cerebral palsy in comparison with normal controls.

    Science.gov (United States)

    Kwon, Yong Hyun; Lee, Hye Young

    2015-02-01

    [Purpose] The purpose of this study was to determine differences in respiratory pressure and pulmonary function among children with spastic diplegic and hemiplegic cerebral palsy (CP) in comparison with children with normal development. [Subjects and Methods] Fourteen children with spastic diplegic CP, 11 children with hemiplegic CP, and 14 children with normal development were recruited. Respiratory pressure was measured and the pulmonary function test (PFT) was performed to evaluate the strength of the respiratory muscles and lung volumetric capacity. [Results] Regarding respiratory pressure, children with spastic diplegic and hemiplegic CP showed significantly lower functions in terms of MIP and MEP compared with children with normal development, although no significant differences were found between children with the two types of CP. In the pulmonary function test, children with spastic diplegic CP showed significantly higher pulmonary function than children with normal development in terms of only FVC and FEV1. [Conclusion] Children with CP showed relatively lower function in terms of respiratory pressure and lung capacity, in comparison with children with normal development. Therefore, respiratory function in children with CP should be carefully evaluated and should receive more attention in a rehabilitation setting.

  1. The mechanical reaction of the pars flaccida of the eardrum to rapid air pressure oscillations modeling different levels of atmospheric disturbances.

    Science.gov (United States)

    Didyk, L A; Dirckx, J J J; Bogdanov, V B; Lysenko, V A; Gorgo, Yu P

    2007-01-01

    Atmospheric pressure fluctuations (APF) might induce mechanical effects in the pars flaccida (PF) of the eardrum. To clarify these effects, different kinds of pressure oscillations (PO), chosen within the range of naturally occurring APF, were applied to the middle ears (ME) of gerbils. The linear displacement of the PF during a PO in the ME was measured by laser interferometry. The compliance of the PF to PO was calculated as the ratio of the amplitude of a PF oscillation to the amplitude of a PO. The displacement of the PF traced the PO in the entire range of frequencies (from 10mHz to 200mHz) and amplitudes (from 10Pa to 110Pa) applied to the ME. Moreover, the PF is found to be displaced by pressure pulses of a few pascals only using a PO with a complex shape. The differences found in the compliance of the PF due to PO with low (less than 20Pa) and high (more than 90Pa) amplitude point out that the mechanism of pressure regulation in the ME through the mechanical reaction of the PF in gerbil ears is better adapted to ordinary levels of natural APF than to extraordinary levels. The implications of these findings for the physiology of the human ME with respect to adaptation to natural APF are discussed.

  2. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles.

    Science.gov (United States)

    Papadopoulos, Emmanuel S; Nikolopoulos, Christos; Badekas, Athanasios; Vagenas, George; Papadakis, Stamatios A; Athanasopoulos, Spyros

    2007-09-12

    Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG) activation sequence of four lower limb muscles. Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i) without brace, ii) with brace and 30 kPa application pressure and iii) with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter) was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris) activation onset. The results showed that overall balance (total stability parameter) was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. These findings suggest that peripheral joint receptors are either not adequately stimulated by the brace application and therefore are not able to

  3. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles

    Directory of Open Access Journals (Sweden)

    Papadakis Stamatios A

    2007-09-01

    Full Text Available Abstract Background Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG activation sequence of four lower limb muscles. Methods Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i without brace, ii with brace and 30 kPa application pressure and iii with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris activation onset. Results The results showed that overall balance (total stability parameter was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. Conclusion These findings suggest that peripheral joint receptors are either not adequately

  4. [Efficiency between the different measurement patterns of home blood pressure monitoring in the follow-up of hypertensive patients in primary care].

    Science.gov (United States)

    De León-Robert, Arleen; Hidalgo-García, Isabel; Gascón-Cánovas, Juan; Antón-Botella, José; López-Alegría, Carmen; Campusano Castellanos, Heidi

    2018-03-29

    To identify the most efficient measurement pattern of home blood pressure monitoring (HBPM) for the follow-up of hypertensive patients in primary care. Validation study of a diagnostic test. Primary care team in Murcia, Spain. One hundred and fifty three hypertensive patients younger than 80 years who met the inclusion criteria, who used HBPM and ambulatory blood pressure monitoring. Performing HBPM for 24hours. The HBPM protocol consisted of recording 2 measurements in the morning and 2 in the evening for 7 days. With the records obtained, the different HBPM patterns were established (7, 6, 5, 4, 3 days). The ROC curves were used for the analysis, together with the correlation coefficients and the Bland-Altman plots. The best areas under the curve for the systolic pressure of the different HBPM patterns corresponded to the 4-day pattern: 0.837 (0.77-0.90); and the 3 day one: 0.834 (0.77-0.90). As for diastolic pressure, the 7-day pattern had an area under the curve of 0.889 (0.84-0.94); followed by the 3 and 4 days patterns, which had the same statistical result both: 0.834 (0.83-0.94). There were no significant differences between correlation coefficients for systolic and diastolic blood pressures. The 3-day pattern showed a lower dispersion in the Bland-Altman plots. The 3 days HBPM pattern is proposed for the follow-up of the hypertensive patient, since it does not have an inferior efficiency to the other patterns. Copyright © 2018 The Author. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Physical and electrical properties of graphene grown under different hydrogen flow in low pressure chemical vapor deposition.

    Science.gov (United States)

    Hussain, Sajjad; Iqbal, Muhmmad Waqas; Park, Jaehyun; Ahmad, Muneer; Singh, Jai; Eom, Jonghwa; Jung, Jongwan

    2014-01-01

    Hydrogen flow during low pressure chemical vapor deposition had significant effect not only on the physical properties but also on the electrical properties of graphene. Nucleation and grain growth of graphene increased at higher hydrogen flows. And, more oxygen-related functional groups like amorphous and oxidized carbon that probably contributed to defects or contamination of graphene remained on the graphene surface at low H2 flow conditions. It is believed that at low hydrogen flow, those remained oxygen or other oxidizing impurities make the graphene films p-doped and result in decreasing the carrier mobility.

  6. 5C.01: LITTLE DIFFERENCE IN SALT INTAKE CRUCIALLY AFFECTS FUTURE BLOOD PRESSURE LEVELS IN THE GENERAL POPULATION.

    Science.gov (United States)

    Murai, S; Takase, H; Sugiura, T; Yamashita, S; Ohte, N; Dohi, Y

    2015-06-01

    A causal relationship between salt and hypertension has been argued for a long time. Epidemiological cross-sectional studies demonstrated higher incidence of hypertension in populations with higher dietary salt than in those with lower dietary salt and interventional studies investigated the effects of drastic changes in dietary salt in individuals. However, there is not sufficient evidence proving that individuals with relatively high salt intakes show an accelerated increase in blood pressure compared to those with a relatively low salt intakes over a long period of observation. Thus, the present observational study was designed to investigate whether individual levels of dietary salt affect future increases in blood pressure in the general population. Individual salt intake was estimated by calculating 24-hour urinary salt excretion using a spot urine in normotensive 6,249 participants in our physical check-up program (53.3 ± 11.4 year-old). After baseline examination, they were followed up for the median of 1,089 days with the endpoint being the development of hypertension. During the follow-up period, hypertension developed in 1,027 participants (73.0 per 1,000 person-years) with the incidence being more frequent in male than female participants. After adjustment for possible risk factors, the hazard ratio of incident hypertension in participants with salt intake higher than the target recommended by the Japanese Ministry of Health, Labour and Welfare (male, <9.0 g/day; female, <7.5 g/day) was 1.25 (95% confidence interval 1.04 to 1.50). In multivariate Cox hazards regression analysis, baseline salt intake and the yearly change in salt intake during the follow-up period (as continuous variables) correlated with the incidence of hypertension. Furthermore, both the yearly increase in salt intake and baseline salt intake showed significant correlations with the yearly increase in systolic blood pressure in multivariate regression analysis after

  7. The structural properties of Zr-based bulk metallic glasses subjected to high pressure torsion at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Boltynjuk, E. V., E-mail: boltynjuk@gmail.com; Ubyivovk, E. V.; Kshumanev, A. M. [Saint Petersburg State University, 28 Universitetskiy pr., Saint Petersburg, 198504 (Russian Federation); Gunderov, D. V.; Lukianov, A. V. [Ufa State Aviation Technical University, K. Marks 12, Ufa, 450000 (Russian Federation); Bednarz, A. [Faculty of Mechanical Engineering and Aeronautics, Department of Aircraft and Aircraft Engines, Rzeszow University of Technology, Al. Powstancow Warszawy 8, 35-959 Rzeszow (Poland); Valiev, R. Z. [Saint Petersburg State University, 28 Universitetskiy pr., Saint Petersburg, 198504 (Russian Federation); Ufa State Aviation Technical University, K. Marks 12, Ufa, 450000 (Russian Federation)

    2016-06-17

    The structural properties of a Zr{sub 62}Cu{sub 22}Al{sub 10}Fe{sub 5}Dy{sub 1} bulk metallic glasses were investigated. Cylindrical rods of the Zr{sub 62}Cu{sub 22}Al{sub 10}Fe{sub 5}Dy{sub 1} BMG were subjected to high pressure torsion at temperatures of 20°C and 150°C. X-ray diffraction, transmission electron microscopy were used to determine peculiarities of the modified structure. Analysis of fracture surfaces, nanohardness measurements were conducted to investigate the influence of structural changes on mechanical behavior of processed samples.

  8. Effect of cetane improver addition into diesel fuel: Methanol mixtures on performance and emissions at different injection pressures

    Directory of Open Access Journals (Sweden)

    Candan Feyyaz

    2017-01-01

    Full Text Available In this study, methanol in ratios of 5-10-15% were incorporated into diesel fuel with the aim of reducing harmful exhaust gasses of Diesel engine, di-tertbutyl peroxide as cetane improver in a ratio of 1% was added into mixture fuels in order to reduce negative effects of methanol on engine performance parameters, and isobutanol of a ratio of 1% was used as additive for preventing phase separation of all mixtures. As results of experiments conducted on a single cylinder and direct injection Diesel engine, methanol caused the increase of NOx emission while reducing CO, HC, CO2, and smoke opacity emissions. It also reduced torque and power values, and increased brake specific fuel consumption values. Cetane improver increased torque and power values slightly compared to methanol-mixed fuels, and reduced brake specific fuel consumption values. It also affected exhaust emission values positively, excluding smoke opacity. Increase of injector injection pressure affected performances of methanol-mixed fuels positively. It also increased injection pressure and NOx emissions, while reducing other exhaust emissions.

  9. Blood pressure, seasonal body fat, heart rate, and ecological differences in Caboclo populations of the Brazilian Amazon.

    Science.gov (United States)

    Silva, H P; James, G D; Crews, D E

    2006-01-01

    This study compares blood pressure (BP) and related cardiovascular risk factors among three Caboclo communities from the Brazilian Amazon. Its purpose is to investigate possible risk differentials related to variable ecological settings and Western influences. Caxiuanã is characterized as a more "traditional" group, while Aracampina and Santana are viewed as more "transitional" in lifestyle. A total of 348 subjects from the three communities were evaluated in the wet or the dry season or in both. Measurements across the communities were compared by season and sex. Results suggest little seasonal variation in average BP, BP change, body fat, or body fat change among men. Conversely, there is substantial seasonal and inter-community variation among women. Additional analyses reveal (1) an inconsistent association between age and BP across the communities; (2) that BMI is not associated with BP transitional communities in either season but is associated with both systolic and diastolic pressure in the most traditional community; and (3) little to no sex effect on BP. These results suggest increased Western influence affects body composition particularly of women. However, increased BMI and fat among transitional Caboclo women does not directly translate into higher BP; rather, their BP appears to be more affected by seasonal stresses. Finally, conditions during the wet season diminish age-related variation in BP, suggesting that during the wet season these Caboclo may be less active. Am. J. Hum. Biol. 18:10-22, 2006. (c) 2005 Wiley-Liss, Inc.

  10. Computer Breakdown as a Stress Factor during Task Completion under Time Pressure: Identifying Gender Differences Based on Skin Conductance

    Directory of Open Access Journals (Sweden)

    René Riedl

    2013-01-01

    Full Text Available In today’s society, as computers, the Internet, and mobile phones pervade almost every corner of life, the impact of Information and Communication Technologies (ICT on humans is dramatic. The use of ICT, however, may also have a negative side. Human interaction with technology may lead to notable stress perceptions, a phenomenon referred to as technostress. An investigation of the literature reveals that computer users’ gender has largely been ignored in technostress research, treating users as “gender-neutral.” To close this significant research gap, we conducted a laboratory experiment in which we investigated users’ physiological reaction to the malfunctioning of technology. Based on theories which explain that men, in contrast to women, are more sensitive to “achievement stress,” we predicted that male users would exhibit higher levels of stress than women in cases of system breakdown during the execution of a human-computer interaction task under time pressure, if compared to a breakdown situation without time pressure. Using skin conductance as a stress indicator, the hypothesis was confirmed. Thus, this study shows that user gender is crucial to better understanding the influence of stress factors such as computer malfunctions on physiological stress reactions.

  11. The Effect of Spinal Tap Test on Different Sensory Modalities of Postural Stability in Idiopathic Normal Pressure Hydrocephalus

    Directory of Open Access Journals (Sweden)

    Katrin Abram

    2016-09-01

    Full Text Available Background/Aims: Postural instability in patients with normal pressure hydrocephalus (NPH is a most crucial symptom leading to falls with secondary complications. The aim of the current study was to evaluate the therapeutic effect of spinal tap on postural stability in these patients. Methods: Seventeen patients with clinical symptoms of NPH were examined using gait scale, computerized dynamic posturography (CDP, and neuropsychological assessment. Examinations were done before and after spinal tap test. Results: The gait score showed a significant improvement 24 h after spinal tap test in all subtests and in the sum score (p Conclusion: Postural stability in NPH is predominantly affected by deficient vestibular functions, which did not improve after spinal tap test. Conditions which improved best were mainly independent from visual control and are based on proprioceptive functions.

  12. Integrated solar combined cycles using gas turbines with partial recuperation and solar integration at different pressure levels

    Science.gov (United States)

    Rovira, Antonio; Sánchez, Consuelo; Fernández, Santiago; Muñoz, Marta; Barbero, Rubén

    2017-06-01

    This work studies and compares two alternatives to improve the solar-to-electricity energy conversion efficiency in integrated solar combined cycle power plants (ISCC), which are based on the use of combined cycles including partial recuperative gas turbines. Each alternative has been integrated into dual and triple pressure levels with reheat heat recovery steam generators (HRSG). Partial recuperation conveys lower heat recovery at the steam generator than in conventional plants, because each MW exchanged in the recuperator is not available at the HRSG. This thermal power decrease at the HRSG may be overcome by the integration of solar energy that is implemented using parabolic trough collectors. Moreover, with such an implementation each solar thermal MW integrated allows a MW of heat recuperation and, thus a MW of fossil fuel saving, thus the solar heat-to-electricity energy conversion rate may reach values up to 50 %, which makes the proposal interesting.

  13. Comparison of the compressive strength of impregnated and nonimpregnated eucalyptus subjected to two different pressures and impregnation times

    Directory of Open Access Journals (Sweden)

    Waldemir Rodrigues

    2004-06-01

    Full Text Available The durability of wood is affected by several factors. For this reason, much research has been done on a variety of chemical compounds for impregnating wood, aimed at preserving it while simultaneously improving its properties. Recent studies of the properties of impregnated wood have demonstrated the possibility of substantially improving its mechanical characteristics. Thus, the purpose of this work was to compare the strength to parallel compression of wooden fibers (Eucalyptus grandis, both nonimpregnated and impregnated with a monocomponent resin, from the standpoint of pressure and impregnation time, aiming at its structural utilization. The results demonstrate that the compressive strength of impregnated test specimens is greater than that of nonimpregnated ones, indicating that monocomponent polyurethane resin can be considered suitable for impregnating wood, since it increases the compressive strength of eucalyptus.

  14. Ethnic differences in blood pressure control among men at Veterans Affairs clinics and other health care sites.

    Science.gov (United States)

    Rehman, Shakaib U; Hutchison, Florence N; Hendrix, Katharine; Okonofua, Eni C; Egan, Brent M

    2005-05-09

    Differential access to health care may contribute to lower blood pressure (BP) control rates to under 140/90 mm Hg in African American compared with white hypertensive patients, especially men (26.5% vs 36.5% of all hypertensive patients in the National Health and Nutrition Examination Survey 1999-2000). The Department of Veterans Affairs (VA) system, which provides access to health care and medications across ethnic and economic boundaries, may reduce disparities in BP control. To test this hypothesis, BP treatment and control groups were compared between African American (VA, n = 4379; non-VA, n = 2754) and white (VA, n = 7987; non-VA, n = 4980) hypertensive men. In both groups, whites were older than African Americans (Pcardiovascular risk.

  15. Pressure overload-induced mild cardiac hypertrophy reduces leftventricular transmural differences in mitochondrial respiratory chainactivity and increases oxidative stress

    Directory of Open Access Journals (Sweden)

    Michel eKINDO

    2012-08-01

    Full Text Available Objective: Increased mechanical stress and contractility characterizes normal left ventricular subendocardium (Endo but whether Endo mitochondrial respiratory chain complex activities is reduced as compared to subepicardium (Epi and whether pressure overload-induced left ventricular hypertrophy (LVH might modulate transmural gradients through increased reactive oxygen species (ROS production is unknown. Methods: LVH was induced by 6 weeks abdominal aortic banding and cardiac structure and function were determined with echocardiography and catheterization in sham-operated and LVH rats (n=10 for each group. Mitochondrial respiration rates, coupling, content and ROS production were measured in LV Endo and Epi, using saponin-permeabilised fibres, Amplex Red fluorescence and citrate synthase activity.Results: In sham, a transmural respiratory gradient was observed with decreases in endo maximal oxidative capacity (-36.7%, P<0.01 and complex IV activity (-57.4%, P<0.05. Mitochondrial hydrogen peroxide (H2O2 production was similar in both LV layers.Aortic banding induced mild LVH (+31.7% LV mass, associated with normal LV fractional shortening and end diastolic pressure. LVH reduced maximal oxidative capacity (-23.6 and -33.3%, increased mitochondrial H2O2 production (+86.9 and +73.1%, free radical leak (+27.2% and +36.3% and citrate synthase activity (+27.2% and +36.3% in Endo and Epi, respectively.Transmural mitochondrial respiratory chain complex IV activity was reduced in LVH (-57.4 vs –12.2%; P=0.02. Conclusions: Endo mitochondrial respiratory chain complexes activities are reduced compared to LV Epi. Mild LVH impairs mitochondrial oxidative capacity, increases oxidative stress and reduces transmural complex IV activity. Further studies will be helpful to determine whether reduced LV transmural gradient in mitochondrial respiration might be a new marker of a transition from uncomplicated toward complicated LVH.

  16. Plantar pressure differences among adults with mild flexible flatfoot, severe flexible flatfoot and normal foot when walking on level surface, walking upstairs and downstairs.

    Science.gov (United States)

    Zhai, Jun Na; Wang, Jue; Qiu, Yu Sheng

    2017-04-01

    [Purpose] This study observed the plantar pressure between flexible flatfoot and normal foot on different walking conditions to find out if flexible flatfoot needs the treatment and how the plantar pressure change while walking upstairs and downstairs. [Subjects and Methods] Fifteen adults with mild flexible flatfoot, fifteen adults with severe flexible flatfoot and fifteen adults with normal foot were examined while walking on a level surface, walking up and down 10 cm and 20 cm stairs. The max force and the arch index were acquired using the RSscan system. The repeated measures ANOVA was performed to analyze the data. [Results] Compared with normal foot, both max force and arch index of severe flatfoot were significantly increased on different walking conditions. When walking down 10 cm and 20 cm stairs, the plantar data of both normal foot and flatfoot were significantly increased. [Conclusion] The plantar pressure of severe flexible flatfoot were significantly larger than that of normal foot on different walking conditions. In addition, the arches of both normal foot and flatfoot were obviously deformed when walking downstairs. It is therefore necessary to be treated for severe flexible flatfoot to prevent further deformation.

  17. A comparative study of pressure-dependent emission characteristics in different gas plasmas induced by nanosecond and picosecond neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers.

    Science.gov (United States)

    Abdulmadjid, Syahrun Nur; Idris, Nasrullah; Marpaung, Alion Mangasi; Pardede, Marincan; Jobiliong, Eric; Hedwig, Rinda; Suliyanti, Maria Margaretha; Ramli, Muliadi; Suyanto, Heri; Kagawa, Kiichiro; Tjia, May On; Lie, Zener Sukra; Lie, Tjung Jie; Kurniawan, Hendrik Koo

    2013-11-01

    An experimental study has been performed on the pressure-dependent plasma emission intensities in Ar, He, and N2 surrounding gases with the plasma induced by either nanosecond (ns) or picosecond (ps) yttrium aluminum garnet laser. The study focused on emission lines of light elements such as H, C, O, and a moderately heavy element of Ca from an agate target. The result shows widely different pressure effects among the different emission lines, which further vary with the surrounding gases used and also with the different ablation laser employed. It was found that most of the maximum emission intensities can be achieved in Ar gas plasma generated by ps laser at low gas pressure of around 5 Torr. This experimental condition is particularly useful for spectrochemical analysis of light elements such as H, C, and O, which are known to suffer from intensity diminution at higher gas pressures. Further measurements of the spatial distribution and time profiles of the emission intensities of H I 656.2 nm and Ca II 396.8 nm reveal the similar role of shock wave excitation for the emission in both ns and ps laser-induced plasmas, while an additional early spike is observed in the plasma generated by the ps laser. The suggested preference of Ar surrounding gas and ps laser was further demonstrated by outperforming the ns laser in their applications to depth profiling of the H emission intensity and offering the prospect for the development of three-dimensional analysis of a light element such as H and C.

  18. Comparison of intraocular pressures at different points in human's cornea before and after laser in situ keratomileusis with tono-pen tonometer.

    Science.gov (United States)

    Li, Xinyu; Li, Guigang; Liu, Lei; Li, Jing

    2011-02-01

    In order to explore the difference of intraocular pressure (IOP) at different points of cornea before and after laser in situ keratomileusis (LASIK), IOP was measured by Tono-Pen Tonometer at central cornea, pericentral cornea and limbus respectively and analyzed statistically. After LASIK, IOP was dropped significantly at central cornea and pericentral cornea (P0.05). There was no statistically significant difference in IOP at different points before LASIK (F=0.110, P=0.896), but statistically significant difference was found after LASIK (F=7.375, P=0.001). It was suggested that reliable IOP after LASIK could be obtained from the limbus by Tono-Pen tonometer.

  19. Evolution of strength and homogeneity in a magnesium AZ31 alloy processed by high-pressure torsion at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yi [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Figueiredo, Roberto B. [Department of Materials Science and Civil Construction, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901 (Brazil); Baudin, Thierry; Brisset, Francois [ICMMO, UMR CNRS 8182 - Bat 410, Universite Paris-Sud, 91405 Orsay Cedex (France); Langdon, Terence G. [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Departments of Aerospace and Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States)

    2012-11-15

    Processing through the application of severe plastic deformation (SPD) is attractive because it produces significant grain refinement and high strength. The standard procedure for performing SPD processing is through the use of equal-channel angular pressing (ECAP) but in practice it is difficult to perform ECAP on the magnesium AZ31 alloy at room temperature because the material cracks or exhibits segmentation. This difficulty was avoided in the present investigation by processing the alloy using high-pressure torsion (HPT). The results show that HPT provides an excellent procedure for producing significant grain refinement in the AZ31 alloy. At temperatures of 296 and 373 K, the processed grain sizes are in the submicrometer range and there is an evolution toward microstructural homogeneity after 5 turns. By contrast, at the higher temperature of 473 K, which is a typical temperature for ECAP, the grains grow during the processing operation. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. The Effect of Spinal Tap Test on Different Sensory Modalities of Postural Stability in Idiopathic Normal Pressure Hydrocephalus.

    Science.gov (United States)

    Abram, Katrin; Bohne, Silvia; Bublak, Peter; Karvouniari, Panagiota; Klingner, Carsten M; Witte, Otto W; Guntinas-Lichius, Orlando; Axer, Hubertus

    2016-01-01

    Postural instability in patients with normal pressure hydrocephalus (NPH) is a most crucial symptom leading to falls with secondary complications. The aim of the current study was to evaluate the therapeutic effect of spinal tap on postural stability in these patients. Seventeen patients with clinical symptoms of NPH were examined using gait scale, computerized dynamic posturography (CDP), and neuropsychological assessment. Examinations were done before and after spinal tap test. The gait score showed a significant improvement 24 h after spinal tap test in all subtests and in the sum score (p tap test. CDP showed significant improvements after spinal tap test in the Sensory Organization Tests 2 (p = 0.017), 4 (p = 0.001), and 5 (p = 0.009) and the composite score (p = 0.01). Patients showed best performance in somatosensory and worst performance in vestibular dominated tests. Vestibular dominated tests did not improve significantly after spinal tap test, while somatosensory and visual dominated tests did. Postural stability in NPH is predominantly affected by deficient vestibular functions, which did not improve after spinal tap test. Conditions which improved best were mainly independent from visual control and are based on proprioceptive functions.

  1. Investigation of a Coolant Mixing Phenomena within the Reactor Pressure Vessel of a VVER-1000 Reactor with Different Simulation Tools

    Directory of Open Access Journals (Sweden)

    V. Sánchez

    2010-01-01

    Full Text Available The Institute of Neutron Physics and Reactor Technology (INR is involved in the qualification of coupled codes for reactor safety evaluations, aiming to improve their prediction capability and acceptability. In the frame of the VVER-1000 Coolant Transient Benchmark Phase 1, RELAP5/PARCS has been extensively assessed. Phase 2 of this benchmark was focused on both multidimensional thermal hydraulic phenomena and core physics. Plant data will be used to qualify the 3D models of TRACE and RELAP5/CFX, which were coupled for this purpose. The developed multidimensional models of the VVER-1000 reactor pressure vessel (RPV as well as the performed calculations will be described in detail. The predicted results are in good agreement with experimental data. It was demonstrated that the chosen 3D nodalization of the RPV is adequate for the description of the coolant mixing phenomena in a VVER-1000 reactor. Even though only a 3D coarse nodalization is used in TRACE, the integral results are comparable to those obtained by RELAP5/CFX.

  2. Comparison of the characteristics of atmospheric pressure plasma jets using different working gases and applications to plasma-cancer cell interactions

    Directory of Open Access Journals (Sweden)

    Hea Min Joh

    2013-09-01

    Full Text Available Atmospheric pressure plasma jets employing nitrogen, helium, or argon gases driven by low-frequency (several tens of kilohertz ac voltage and pulsed dc voltage were fabricated and characterized. The changes in discharge current, optical emission intensities from reactive radicals, gas temperature, and plume length of plasma jets with the control parameters were measured and compared. The control parameters include applied voltage, working gas, and gas flow rate. As an application to plasma-cancer cell interactions, the effects of atmospheric pressure plasma jet on the morphology and intracellular reactive oxygen species (ROS level of human lung adenocarcinoma cell (A549 and human bladder cancer cell (EJ were explored. The experimental results show that the plasma can effectively control the intracellular concentrations of ROS. Although there exist slight differences in the production of ROS, helium, argon, or nitrogen plasma jets are found to be useful in enhancing the intracellular ROS concentrations in cancer cells.

  3. Differences in mean arterial pressure of young and elderly people measured by oscilometry during inflation and deflation of the arm cuff.

    Science.gov (United States)

    Fabian, Vratislav; Havlik, Jan; Dvorak, Jan; Kremen, Vaclav; Sajgalik, Pavol; Bellamy, Valentin; Schirger, John A; Sovka, Pavel; Johnson, Bruce D

    2016-12-01

    Systemic arterial blood pressure (BP) is one of the most important parameters of the cardiovascular system. An oscillometric NIBP monitor was specifically designed to measure oscillometric pulsations and mean arterial pressure (MAP) during inflation and deflation of the cuff. Nineteen healthy young (age 23.1±1.7 years; mean±SD) and 35 elderly (83.9±7.9 years; mean±SD) subjects were studied. Differential analysis of MAP during inflation and deflation show mean |ΔMAP|=2.9±2.6 mm Hg in the young group (mean±SD) and |ΔMAP|=6.3±5.2 mm Hg for seniors (mean±SD). There was a significant difference (pdeflation between both groups. In about 50% of elderly subjects |ΔMAP| was higher than 5 mm Hg. Potential clinical relevance of the method needs to be further evaluated.

  4. Impact of Different Ventilation Strategies on Driving Pressure, Mechanical Power, and Biological Markers During Open Abdominal Surgery in Rats.

    Science.gov (United States)

    Maia, Lígia de A; Samary, Cynthia S; Oliveira, Milena V; Santos, Cintia L; Huhle, Robert; Capelozzi, Vera L; Morales, Marcelo M; Schultz, Marcus J; Abreu, Marcelo G; Pelosi, Paolo; Silva, Pedro L; Rocco, Patricia Rieken Macedo

    2017-10-01

    Intraoperative mechanical ventilation may yield lung injury. To date, there is no consensus regarding the best ventilator strategy for abdominal surgery. We aimed to investigate the impact of the mechanical ventilation strategies used in 2 recent trials (Intraoperative Protective Ventilation [IMPROVE] trial and Protective Ventilation using High versus Low PEEP [PROVHILO] trial) on driving pressure (ΔPRS), mechanical power, and lung damage in a model of open abdominal surgery. Thirty-five Wistar rats were used, of which 28 were anesthetized, and a laparotomy was performed with standardized bowel manipulation. Postoperatively, animals (n = 7/group) were randomly assigned to 4 hours of ventilation with: (1) tidal volume (VT) = 7 mL/kg and positive end-expiratory pressure (PEEP) = 1 cm H2O without recruitment maneuvers (RMs) (low VT/low PEEP/RM-), mimicking the low-VT/low-PEEP strategy of PROVHILO; (2) VT = 7 mL/kg and PEEP = 3 cm H2O with RMs before laparotomy and hourly thereafter (low VT/moderate PEEP/4 RM+), mimicking the protective ventilation strategy of IMPROVE; (3) VT = 7 mL/kg and PEEP = 6 cm H2O with RMs only before laparotomy (low VT/high PEEP/1 RM+), mimicking the strategy used after intubation and before extubation in PROVHILO; or (4) VT = 14 mL/kg and PEEP = 1 cm H2O without RMs (high VT/low PEEP/RM-), mimicking conventional ventilation used in IMPROVE. Seven rats were not tracheotomized, operated, or mechanically ventilated, and constituted the healthy nonoperated and nonventilated controls. Low VT/moderate PEEP/4 RM+ and low VT/high PEEP/1 RM+, compared to low VT/low PEEP/RM- and high VT/low PEEP/RM-, resulted in lower ΔPRS (7.1 ± 0.8 and 10.2 ± 2.1 cm H2O vs 13.9 ± 0.9 and 16.9 ± 0.8 cm H2O, respectively; Pmechanical power (63 ± 7 and 79 ± 20 J/min vs 110 ± 10 and 120 ± 20 J/min, respectively; P = .007). Low VT/high PEEP/1 RM+ was associated with less alveolar collapse than low VT/low PEEP/RM- (P = .03). E-cadherin expression was higher in

  5. Different relationships between pulse pressure and mortality in heart failure with reduced, mid-range and preserved ejection fraction.

    Science.gov (United States)

    Teng, Tiew-Hwa Katherine; Tay, Wan Ting; Dahlstrom, Ulf; Benson, Lina; Lam, Carolyn S P; Lund, Lars H

    2018-03-01

    In heart failure (HF), pulse pressure (PP) may reflect both vascular stiffness and left ventricular function, but its prognostic role in relation to ejection fraction (EF) is poorly understood. In the Swedish Heart Failure Registry, we investigated the association between PP and 1-year mortality in patients with HF and reduced (HFrEF, cubic splines. Among 36,770 patients discharged alive or enrolled as out-patients with 1-year follow-up (mean age 74±12years, 63% men, 56% HFrEF, 21% HFmrEF, 23% HFpEF), crude one-year mortality was 18%. Mean PP increased across EF groups: 51±16 in HFrEF, 57±18 in HFmrEF, 60±19mmHg in HFpEF. In crude regression splines, the association between PP and mortality was U-shaped in HFmrEF and HFpEF, but curvilinear with only low PP associated with mortality in HFrEF. In multivariable analyses, a significant interaction by EF group and PP was observed (p interaction =0.015): low PP was associated with higher mortality in HFrEF (adjusted OR [1st vs. 4th quintile]=1.40, 95% CI 1.18-1.67) and HFpEF (1.43, 1.14-1.81) but only by trend in HFmrEF; high PP had a trend towards higher mortality in HFmrEF (5th vs. 3rd quintile=1.30, 1.00-1.69) and HFpEF (1.25, 0.98-1.61). The association between PP and mortality in HF was influenced by EF. Low PP was independently associated with mortality in HFrEF and HFpEF and by trend in HFmrEF. High PP was independently associated with mortality by trend in HFmrEF and HFpEF. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. An experimental study on single phase convection heat transfer and pressure drop in two brazed plate heat exchangers with different chevron shapes and hydraulic diameters

    International Nuclear Information System (INIS)

    Kim, Man Bae; Park, Chang Yong

    2017-01-01

    An experimental study on heat transfer and pressure drop characteristics was performed at single phase flow in two Brazed plate heat exchangers (BPHEs) with different geometries. The corrugation density of one of the BPHE (Type II) was two times as high as that of the other BPHE (Type I). The hydraulic diameter of the type II BPHE was 2.13 mm, which was 38 % smaller than that of the type I BPHE. Also, the cross section shape of the flow channels for the type II BPHE was different from that for conventional BPHEs due to the unusual corrugation patterns and brazing points. The experimental conditions for temperatures were varied from 4.6 °C to 49.1 °C, and for mass flow rates were changed from 0.07 kg/s to 1.24 kg/s. The measured results showed that pressure drop in the type II BPHE was about 110 % higher than that in the type I BPHE. Nu of the type II was higher than that of the type I BPHE and the enhancement became larger with the increase of Re at the ranges above 800. New correlations for fF and Nu were proposed by this study and their prediction accuracy could be improved by considering the surface enlargement factor in the correlations. The performance evaluation of the two BPHEs was performed by (j/f F 1 /3 ) which represented the ratio of heat transfer and pressure drop performance. Also, a new parameter, the capacity compactness of PHE, was proposed and it presented the PHE capacity per unit volume and unit log mean temperature difference. The comparison showed that the two BPHEs had similar values of the (j/f F 1 /3 ), whereas they had significantly different values of the capacity compactness. The capacity compactness of the type II BPHE was 1.5 times higher than that for the type I BPHE.

  7. Comparison of intraocular pressure during the application of a liquid patient interface (FEMTO LDV Z8) for femtosecond laser-assisted cataract surgery using two different vacuum levels.

    Science.gov (United States)

    Ebner, Martina; Mariacher, Siegfried; Januschowski, Kai; Boden, Katrin; Seuthe, Anna-Maria; Szurman, Peter; Boden, Karl Thomas

    2017-08-01

    To evaluate intraocular pressure (IOP) using the application of a novel liquid patient interface for femtosecond laser-assisted cataract surgery with the FEMTO LDV Z8. IOP was evaluated in enucleated porcine eyes prior, during and after the application of the Femto LDV Z8 liquid patient interface (Ziemer Ophthalmic Systems, Switzerland) using intracameral cannulation (n=20), intravitreal cannulation (n=20), rebound tonometry (n=20) and indentation tonometry (n=20). Pressure was assessed prior vacuum, during vacuum (30 s, 1 min, 2 min, 3 min) and after releasing the vacuum (1 min and 2 min). Two groups with different predefined vacuum levels (350 mbar, 420 mbar) were investigated. Mean intracameral pressure (±SD) increased during vacuum application from 20 mm Hg to 52.00 mm Hg (±6.35mm Hg; p=0.005) and 45.18 mmHg (±4.34 mm Hg; p=0.005) for the 420 mbar and the 350 mbar vacuum levels, respectively. Mean intravitreal pressure increased from 20 mm Hg to 25.60 mm Hg (±9.85 mm Hg; p=0.058) and 28.10 mm Hg (±2.54 mm Hg; p=0.059) for the 420 mbar and the 350 mbar vacuum levels, respectively. Pressure values from indentation and rebound tonometry were in between intracameral and intravitreal values. Mean intracameral IOP was 18.1% higher (p=0.019) in the 420 mbar group compared with the 350 mbar group. During vacuum application of the liquid patient interface of the Femto LDV Z8 for femtosecond laser-assisted cataract surgery, IOP values were higher in the anterior chamber compared with the intravitreal pressure measurements. The higher predefined vacuum level (350 mbar vs 420 mbar) resulted in significant higher intracameral IOP. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Effects of blood pressure lowering on cardiovascular outcomes in different cardiovascular risk groups among participants with type 2 diabetes

    NARCIS (Netherlands)

    van Dieren, Susan; Kengne, Andre P.; Chalmers, John; Beulens, Joline W. J.; Cooper, Mark E.; Grobbee, Diederick E.; Harrap, Stephen; Mancia, Giuseppe; Neal, Bruce; Patel, Anushka; Poulter, Neil; van der Schouw, Yvonne T.; Woodward, Mark; Zoungas, Sophia

    2012-01-01

    To asses differences in treatment effects of a fixed combination of perindopril-indapamide on major clinical outcomes in patients with type 2 diabetes across subgroups of cardiovascular risk. 11,140 participants with type 2 diabetes, from the ADVANCE trial, were randomized to perindopril-indapamide

  9. Effect of Laser Irradiation at Different Wavelengths (940, 808, and 658 nm) on Pressure Ulcer Healing: Results from a Clinical Study.

    Science.gov (United States)

    Taradaj, J; Halski, T; Kucharzewski, M; Urbanek, T; Halska, U; Kucio, C

    2013-01-01

    THE AIM OF THE STUDY WAS TO ASSESS THE EFFICACY OF LASER THERAPY (AT DIFFERENT WAVELENGTHS: 940, 808, and 658 nm) for treating pressure ulcers. The primary endpoint in this trial included both the percentage reduction of the ulcer surface area and the percentage of completely healed wounds after one month of therapy (ulcer healing rate). The secondary endpoint was the ulcer healing rate at the follow-up evaluation (3 months after the end of the study). In total, 72 patients with stage II and III pressure ulcers received laser therapy once daily, 5 times per week for 1 month using a (GaAlAs) diode laser with a maximum output power of 50 mW and continuous radiation emission. Three separate wavelengths were used for the laser treatment: 940 nm (group I), 808 nm (group II), and 658 nm (group III). An average dose of 4 J/cm(2) was applied. In group IV, a placebo was applied (laser device was turned off). The laser therapy at a wavelength of 658 nm appeared to be effective at healing pressure ulcers. The wavelengths of 808 and 940 nm did not have any effect in our study.

  10. Effect of Laser Irradiation at Different Wavelengths (940, 808, and 658 nm on Pressure Ulcer Healing: Results from a Clinical Study

    Directory of Open Access Journals (Sweden)

    J. Taradaj

    2013-01-01

    Full Text Available The aim of the study was to assess the efficacy of laser therapy (at different wavelengths: 940, 808, and 658 nm for treating pressure ulcers. The primary endpoint in this trial included both the percentage reduction of the ulcer surface area and the percentage of completely healed wounds after one month of therapy (ulcer healing rate. The secondary endpoint was the ulcer healing rate at the follow-up evaluation (3 months after the end of the study. In total, 72 patients with stage II and III pressure ulcers received laser therapy once daily, 5 times per week for 1 month using a (GaAlAs diode laser with a maximum output power of 50 mW and continuous radiation emission. Three separate wavelengths were used for the laser treatment: 940 nm (group I, 808 nm (group II, and 658 nm (group III. An average dose of 4 J/cm2 was applied. In group IV, a placebo was applied (laser device was turned off. The laser therapy at a wavelength of 658 nm appeared to be effective at healing pressure ulcers. The wavelengths of 808 and 940 nm did not have any effect in our study.

  11. Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure.

    Science.gov (United States)

    Knipfer, Thorsten; Eustis, Ashley; Brodersen, Craig; Walker, Andrew M; McElrone, Andrew J

    2015-08-01

    Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and root pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, root pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with root pressure and gas exchange responses. © 2014 John Wiley & Sons Ltd.

  12. Comparison of Reef Fish Survey Data Gathered by Open and Closed Circuit SCUBA Divers Reveals Differences in Areas With Higher Fishing Pressure.

    Science.gov (United States)

    Gray, Andrew E; Williams, Ivor D; Stamoulis, Kostantinos A; Boland, Raymond C; Lino, Kevin C; Hauk, Brian B; Leonard, Jason C; Rooney, John J; Asher, Jacob M; Lopes, Keolohilani H; Kosaki, Randall K

    2016-01-01

    Visual survey by divers using open-circuit (OC) SCUBA is the most widely used approach to survey coral reef fishes. Therefore, it is important to quantify sources of bias in OC surveys, such as the possibility that avoidance of OC divers by fishes can lead to undercounting in areas where targeted species have come to associate divers with a risk of being speared. One potential way to reduce diver avoidance is to utilize closed circuit rebreathers (CCRs), which do not produce the noise and bubbles that are a major source of disturbance associated with OC diving. For this study, we conducted 66 paired OC and CCR fish surveys in the Main Hawaiian Islands at locations with relatively high, moderate, and light fishing pressure. We found no significant differences in biomass estimates between OC and CCR surveys when data were pooled across all sites, however there were differences at the most heavily fished location, Oahu. There, biomass estimates from OC divers were significantly lower for several targeted fish groups, including surgeonfishes, targeted wrasses, and snappers, as well as for all targeted fishes combined, with mean OC biomass between 32 and 68% of mean CCR biomass. There were no clear differences between OC and CCR biomass estimates for these groups at sites with moderate or low fishing pressure, or at any location for other targeted fish groups, including groupers, parrotfishes, and goatfishes. Bias associated with avoidance of OC divers at heavily fished locations could be substantially reduced, or at least calibrated for, by utilization of CCR. In addition to being affected by fishing pressure, the extent to which avoidance of OC divers is problematic for visual surveys varies greatly among taxa, and is likely to be highly influenced by the survey methodology and dimensions used.

  13. Comparison of Reef Fish Survey Data Gathered by Open and Closed Circuit SCUBA Divers Reveals Differences in Areas With Higher Fishing Pressure.

    Directory of Open Access Journals (Sweden)

    Andrew E Gray

    Full Text Available Visual survey by divers using open-circuit (OC SCUBA is the most widely used approach to survey coral reef fishes. Therefore, it is important to quantify sources of bias in OC surveys, such as the possibility that avoidance of OC divers by fishes can lead to undercounting in areas where targeted species have come to associate divers with a risk of being speared. One potential way to reduce diver avoidance is to utilize closed circuit rebreathers (CCRs, which do not produce the noise and bubbles that are a major source of disturbance associated with OC diving. For this study, we conducted 66 paired OC and CCR fish surveys in the Main Hawaiian Islands at locations with relatively high, moderate, and light fishing pressure. We found no significant differences in biomass estimates between OC and CCR surveys when data were pooled across all sites, however there were differences at the most heavily fished location, Oahu. There, biomass estimates from OC divers were significantly lower for several targeted fish groups, including surgeonfishes, targeted wrasses, and snappers, as well as for all targeted fishes combined, with mean OC biomass between 32 and 68% of mean CCR biomass. There were no clear differences between OC and CCR biomass estimates for these groups at sites with moderate or low fishing pressure, or at any location for other targeted fish groups, including groupers, parrotfishes, and goatfishes. Bias associated with avoidance of OC divers at heavily fished locations could be substantially reduced, or at least calibrated for, by utilization of CCR. In addition to being affected by fishing pressure, the extent to which avoidance of OC divers is problematic for visual surveys varies greatly among taxa, and is likely to be highly influenced by the survey methodology and dimensions used.

  14. Comparison of Reef Fish Survey Data Gathered by Open and Closed Circuit SCUBA Divers Reveals Differences in Areas With Higher Fishing Pressure

    Science.gov (United States)

    Stamoulis, Kostantinos A.; Boland, Raymond C.; Lino, Kevin C.; Hauk, Brian B.; Leonard, Jason C.; Asher, Jacob M.; Lopes, Keolohilani H.; Kosaki, Randall K.

    2016-01-01

    Visual survey by divers using open-circuit (OC) SCUBA is the most widely used approach to survey coral reef fishes. Therefore, it is important to quantify sources of bias in OC surveys, such as the possibility that avoidance of OC divers by fishes can lead to undercounting in areas where targeted species have come to associate divers with a risk of being speared. One potential way to reduce diver avoidance is to utilize closed circuit rebreathers (CCRs), which do not produce the noise and bubbles that are a major source of disturbance associated with OC diving. For this study, we conducted 66 paired OC and CCR fish surveys in the Main Hawaiian Islands at locations with relatively high, moderate, and light fishing pressure. We found no significant differences in biomass estimates between OC and CCR surveys when data were pooled across all sites, however there were differences at the most heavily fished location, Oahu. There, biomass estimates from OC divers were significantly lower for several targeted fish groups, including surgeonfishes, targeted wrasses, and snappers, as well as for all targeted fishes combined, with mean OC biomass between 32 and 68% of mean CCR biomass. There were no clear differences between OC and CCR biomass estimates for these groups at sites with moderate or low fishing pressure, or at any location for other targeted fish groups, including groupers, parrotfishes, and goatfishes. Bias associated with avoidance of OC divers at heavily fished locations could be substantially reduced, or at least calibrated for, by utilization of CCR. In addition to being affected by fishing pressure, the extent to which avoidance of OC divers is problematic for visual surveys varies greatly among taxa, and is likely to be highly influenced by the survey methodology and dimensions used. PMID:27936044

  15. Effect of Laser Irradiation at Different Wavelengths (940, 808, and 658 nm) on Pressure Ulcer Healing: Results from a Clinical Study

    OpenAIRE

    Taradaj, J.; Halski, T.; Kucharzewski, M.; Urbanek, T.; Halska, U.; Kucio, C.

    2013-01-01

    The aim of the study was to assess the efficacy of laser therapy (at different wavelengths: 940, 808, and 658?nm) for treating pressure ulcers. The primary endpoint in this trial included both the percentage reduction of the ulcer surface area and the percentage of completely healed wounds after one month of therapy (ulcer healing rate). The secondary endpoint was the ulcer healing rate at the follow-up evaluation (3 months after the end of the study). In total, 72 patients with stage II and ...

  16. Study of microstructure, texture and mechanical properties of Zr–2.5Nb alloy pressure tubes fabricated with different processing routes

    International Nuclear Information System (INIS)

    Saibaba, N.; Vaibhaw, Kumar; Neogy, S.; Mani Krishna, K.V.; Jha, S.K.; Phani Babu, C.; Ramana Rao, S.V.; Srivastava, D.; Dey, G.K.

    2013-01-01

    Different fabrication trials involving the variation in three important stages of Zr–2.5Nb pressure tube were undertaken. The variations were with respect to the mode of breaking the cast structure of the ingot (forging vs extrusion), the hot extrusion ratio and the number of subsequent cold work stages to produce the finished tube. It was observed that the forging process resulted in superior performance in breaking the cast structure. Higher extrusion ratios resulted in more favorable texture and microstructure. More continuity of the beta phase was observed in the final microstructure for the route involving the single cold work step subsequent to hot extrusion

  17. Influence of different levels of immersion in water on the pulmonary function and respiratory muscle pressure in healthy individuals: observational study.

    Science.gov (United States)

    de Andrade, Armèle Dornelas; Júnior, Jader Carneiro; Lins de Barros Melo, Talita Lourdes; Rattes Lima, Catarina Souza Ferreira; Brandão, Daniella Cunha; de Melo Barcelar, Jacqueline

    2014-09-01

    Immersion in water, with the head above the water line, causes acute physiological changes in the pulmonary and cardiovascular systems. The aim of this study was to evaluate the acute physiological responses to immersion on lung volumes and respiratory muscle strength at different depths. A cross-sectional study was conducted in 28 healthy individuals (21.75 ± 1.99 years; 13 men and 15 women). Anthropometric and spirometric data as well as respiratory muscle strength were evaluated. Evaluations were carried out on dry land (DL) and in a pool at three different levels of immersion: iliac crests (IC), xiphoid appendix of the sternum (XA) and clavicles (CL). The order of evaluation for spirometry and maximal inspiratory and expiratory pressures between DL and the different levels of immersion was randomized. The ANOVA test for repeated measures with post hoc Tukey was applied to compare the variables. Vital capacity exhibited lower values at the CL level compared with DL, XA and IC (p function and respiratory muscle strength when compared with the values measured out of the water and immersed at the IC level in healthy individuals, demonstrating the influence of hydrostatic pressure on the respiratory system. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Physical and mechanical properties of pressure-molded and injection-molded denture base acrylics in different conditions

    Directory of Open Access Journals (Sweden)

    Yousef A Shibat Al Hamd

    2014-01-01

    Conclusion: The three tested denture base acrylics did not show any significant differences in processing shrinkage. However, ProBase Hot showed significantly lower bending deflection values than Lucitone 199 and SR-Ivocap. Compared to Lucitone 199 and SR-Ivocap, ProBase Hot is a tougher and a stiffer material. Hence, it is more likely to fracture readily if subjected to extreme loading conditions due to the accidental fall of the denture on a hard surface or if the denture wearer inadvertently bites on a particularly hard particle.

  19. Ion transfer from an atmospheric pressure ion funnel into a mass spectrometer with different interface options: Simulation-based optimization of ion transmission efficiency.

    Science.gov (United States)

    Mayer, Thomas; Borsdorf, Helko

    2016-02-15

    We optimized an atmospheric pressure ion funnel (APIF) including different interface options (pinhole, capillary, and nozzle) regarding a maximal ion transmission. Previous computer simulations consider the ion funnel itself and do not include the geometry of the following components which can considerably influence the ion transmission into the vacuum stage. Initially, a three-dimensional computer-aided design (CAD) model of our setup was created using Autodesk Inventor. This model was imported to the Autodesk Simulation CFD program where the computational fluid dynamics (CFD) were calculated. The flow field was transferred to SIMION 8.1. Investigations of ion trajectories were carried out using the SDS (statistical diffusion simulation) tool of SIMION, which allowed us to evaluate the flow regime, pressure, and temperature values that we obtained. The simulation-based optimization of different interfaces between an atmospheric pressure ion funnel and the first vacuum stage of a mass spectrometer require the consideration of fluid dynamics. The use of a Venturi nozzle ensures the highest level of transmission efficiency in comparison to capillaries or pinholes. However, the application of radiofrequency (RF) voltage and an appropriate direct current (DC) field leads to process optimization and maximum ion transfer. The nozzle does not hinder the transfer of small ions. Our high-resolution SIMION model (0.01 mm grid unit(-1) ) under consideration of fluid dynamics is generally suitable for predicting the ion transmission through an atmospheric-vacuum system for mass spectrometry and enables the optimization of operational parameters. A Venturi nozzle inserted between the ion funnel and the mass spectrometer permits maximal ion transmission. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Extrapolation of bulk rock elastic moduli of different rock types to high pressure conditions and comparison with texture-derived elastic moduli

    Science.gov (United States)

    Ullemeyer, Klaus; Lokajíček, Tomás; Vasin, Roman N.; Keppler, Ruth; Behrmann, Jan H.

    2018-02-01

    In this study elastic moduli of three different rock types of simple (calcite marble) and more complex (amphibolite, micaschist) mineralogical compositions were determined by modeling of elastic moduli using texture (crystallographic preferred orientation; CPO) data, experimental investigation and extrapolation. 3D models were calculated using single crystal elastic moduli, and CPO measured using time-of-flight neutron diffraction at the SKAT diffractometer in Dubna (Russia) and subsequently analyzed using Rietveld Texture Analysis. To define extrinsic factors influencing elastic behaviour, P-wave and S-wave velocity anisotropies were experimentally determined at 200, 400 and 600 MPa confining pressure. Functions describing variations of the elastic moduli with confining pressure were then used to predict elastic properties at 1000 MPa, revealing anisotropies in a supposedly crack-free medium. In the calcite marble elastic anisotropy is dominated by the CPO. Velocities continuously increase, while anisotropies decrease from measured, over extrapolated to CPO derived data. Differences in velocity patterns with sample orientation suggest that the foliation forms an important mechanical anisotropy. The amphibolite sample shows similar magnitudes of extrapolated and CPO derived velocities, however the pattern of CPO derived velocity is closer to that measured at 200 MPa. Anisotropy decreases from the extrapolated to the CPO derived data. In the micaschist, velocities are higher and anisotropies are lower in the extrapolated data, in comparison to the data from measurements at lower pressures. Generally our results show that predictions for the elastic behavior of rocks at great depths are possible based on experimental data and those computed from CPO. The elastic properties of the lower crust can, thus, be characterized with an improved degree of confidence using extrapolations. Anisotropically distributed spherical micro-pores are likely to be preserved, affecting

  1. Artificial neural networks can be effectively used to model changes of intracranial pressure (ICP) during spinal surgery using different non invasive ICP surrogate estimators.

    Science.gov (United States)

    Watad, Abdulla; Bragazzi, Nicola L; Bacigaluppi, Susanna; Amital, Howard; Watad, Samaa; Sharif, Kassem; Bisharat, Bishara; Siri, Anna; Mahamid, Ala; Abu Ras, Hakim; Nasr, Ahmed; Bilotta, Federico; Robba, Chiara; Adawi, Mohammad

    2018-02-23

    Artificial Intelligence (AI) techniques play a major role in anesthesiology, even though their importance is often overlooked. In the extant literature, AI approaches, such as Artificial Neural Networks (ANNs), have been underutilized, mainly being used to model patient's consciousness state, to predict the precise amount of anesthetic gases, the level of analgesia, or the need of anesthesiological blocks, among others. In the field of neurosurgery, ANNs have been effectively applied to the diagnosis and prognosis of cerebral tumors, seizures, low back pain, and also to the monitoring of intracranial pressure (ICP). A MultiLayer Perceptron (MLP), which is a feedforward ANN, with hyperbolic tangent as activation function in the input/hidden layers, softmax as activation function in the output layer, and cross-entropy as error function, was used to model the impact of prone versus supine position and the use of positive end expiratory pressure (PEEP) on ICP in a sample of 30 patients undergoing spinal surgery. Different non invasive surrogate estimations of ICP have been used and compared: namely, mean optic nerve sheath diameter (ONSD), non invasive estimated cerebral perfusion pressure (NCPP), pulsatility index (PI), ICP derived from PI (ICP-PI), and flow velocity diastolic formula (FVDICP). ONSD proved to be a more robust surrogate estimation of ICP, with a predictive power of 75%, whilst the power of NCPP, ICP-PI, PI, and FVDICP were 60.5%, 54.8%, 53.1%, and 47.7%, respectively. Our MLP analysis confirmed our findings previously obtained with regression, correlation, multivariate Receiving Operator Curve (multi-ROC) analyses. ANNs can be successfully used to predict the effects of prone versus supine position and PEEP on ICP in patients undergoing spinal surgery using different non invasive surrogate estimators of ICP.

  2. Racial Differences in Abnormal Ambulatory Blood Pressure Monitoring Measures: Results From the Coronary Artery Risk Development in Young Adults (CARDIA) Study

    Science.gov (United States)

    Lewis, Cora E.; Diaz, Keith M.; Carson, April P.; Kim, Yongin; Calhoun, David; Yano, Yuichiro; Viera, Anthony J.; Shimbo, Daichi

    2015-01-01

    BACKGROUND Several ambulatory blood pressure monitoring (ABPM) measures have been associated with increased cardiovascular disease risk independent of clinic blood pressure (BP). African Americans have higher clinic BP compared with Whites but few data are available on racial differences in ABPM measures. METHODS We compared ABPM measures between African American (n = 178) and White (n = 103) participants at the Year 5 Coronary Artery Risk Development in Young Adults study visit. BP was measured during a study visit and the second and third measurements were averaged. ABPM was conducted over the following 24 hours. RESULTS Mean ± SD age of participants was 29.8±3.8 years and 30.8±3.5 years for African Americans and Whites, respectively. Mean daytime systolic BP (SBP) was 3.90 (SD 1.18) mm Hg higher among African Americans compared with Whites (P ABPM was higher among African Americans compared with Whites. CONCLUSIONS These data suggest racial differences in several ABPM measures exist. PMID:25376639

  3. Cooperation in simulating a pressurized coal dust reactor with different simulation programs; Kooperation bei der Simulation eines Druckkohlenstaubreaktors mit unterschiedlichen Simulationsprogrammen

    Energy Technology Data Exchange (ETDEWEB)

    Ayar, A.; Hecken, M. [Technische Hochschule Aachen (Germany). Lehrstuhl fuer Waermeuebertragung und Klimatechnik; Mohr, M.; Murza, S. [Bochum Univ. (Germany). Lehrstuhl fuer Energieanlagentechnik; Richter, S.; Stroehle, J. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

    1999-09-01

    The contribution presents the results of a cooperative project of three different universities - Department of Heat Transfer and Air Conditioning Engineering (WUeK) of RWTH Aachen, Department of Power Sytems Engineering (LEAT) of Ruhr-Universitaet Bochum, Institute of Chemical Engineering and Steam Boiler Engineering (IVD) of Stuttgart University - which involved modellilng a benchmark flame of the pressurized coal dust reactor of the Departmentof Heat Transfer and Air Conditioning Engineering. The conditions of the benchmark flame reflect a real firnace condition which so far has never been investigated experimentally. The contribution compares the results of the three different simulation programs and presents an outlook to the necessary further developments of the programs for modelling plants for pressurized coal dust combustion. [Deutsch] Es werden die Ergebnisse der Zusammenarbeit der drei beteiligten Institute - Lehrstuhl fuer Waermeuebertragung und Klimatechnik (WUeK) der RWTH Aachen, Lehrstuhl fuer Energieanlagentechnik (LEAT) der Ruhr-Uni Bochum und Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Uni Stuttgart - bei der Modellierung einer Benchmarkflamme des Druckkohlenstaubreaktors am Lehrstuhl fuer Waermeuebertragung und Klimatechnik dargestellt. Diese Bedingungen fuer diese Benchmarkflamme sind einem realen, bis dato noch nicht experimentell untersuchten Feuerungszustand nachempfunden. Der Beitrag beinhaltet den Vergleich der mit drei unterschiedlichen Simulationsprogrammen erzielten Ergebnisse und gibt einen Ausblick auf die notwendigen Weiterentwicklungen der Programme hinsichtlich der Modellierung druckkohlenstaubgefeuerter Anlagen. (orig.)

  4. Sex difference in blood pressure among South Asian diaspora in Europe and North America and the role of BMI: a meta-analysis.

    Science.gov (United States)

    de Munter, J S L; Agyemang, C; van Valkengoed, I G; Bhopal, R; Stronks, K

    2011-07-01

    It is unclear whether the sex difference that is known to occur in blood pressure (BP) is similar in some South Asian populations. This study presents a meta-analysis of the sex difference in BP, hypertension and the role of body mass index (BMI) in South Asian diaspora compared with populations of European descent. We systematically searched for studies that reported BP and hypertension among South Asian descent populations living in Europe and North America. Weighted mean differences in BP and risk ratios (RR) for hypertension were calculated for men and women. We included 11 studies in this meta-analysis. In general, men had a higher BP and prevalence of hypertension than women, for example, systolic BP was higher in men than in women among the Indian (7.21 mm Hg, 95% confidence interval (CI): 4.46-9.95) and European populations (6.12 mm Hg, 95% CI: 4.45-7.80). The difference was less in the Pakistani population (4.00 mm Hg, 95% CI: 2.65-5.36). The Bangladeshi population showed a comparatively small sex difference in systolic (2.93 mm Hg, 95% CI: 1.20-4.66) and diastolic BP (0.68 mm Hg, 95% CI: -1.76 to 3.12) and prevalence of hypertension (RR 1.28, 95% CI: 0.66-2.46). Sex differences in BMI for the South Asian populations were greater than those in Europeans. The Indian population had similar sex differences in BP and hypertension compared with Europeans, but Pakistani and Bangladeshi had smaller sex differences. Sex differences in BMI might relate to the blunted sex differences in BP in Pakistani and Bangladeshi populations. Further research should focus on factors that underlie this intriguing sex difference among South Asian populations.

  5. Atmospheric pressure chemical ionization studies of non-polar isomeric hydrocarbons using ion mobility spectrometry and mass spectrometry with different ionization techniques

    Science.gov (United States)

    Borsdorf, H.; Nazarov, E. G.; Eiceman, G. A.

    2002-01-01

    The ionization pathways were determined for sets of isomeric non-polar hydrocarbons (structural isomers, cis/trans isomers) using ion mobility spectrometry and mass spectrometry with different techniques of atmospheric pressure chemical ionization to assess the influence of structural features on ion formation. Depending on the structural features, different ions were observed using mass spectrometry. Unsaturated hydrocarbons formed mostly [M - 1]+ and [(M - 1)2H]+ ions while mainly [M - 3]+ and [(M - 3)H2O]+ ions were found for saturated cis/trans isomers using photoionization and 63Ni ionization. These ionization methods and corona discharge ionization were used for ion mobility measurements of these compounds. Different ions were detected for compounds with different structural features. 63Ni ionization and photoionization provide comparable ions for every set of isomers. The product ions formed can be clearly attributed to the structures identified. However, differences in relative abundance of product ions were found. Although corona discharge ionization permits the most sensitive detection of non-polar hydrocarbons, the spectra detected are complex and differ from those obtained with 63Ni ionization and photoionization. c. 2002 American Society for Mass Spectrometry.

  6. Role of beta1-adrenoreceptors at visual associative cortex in rats of different age in the impact on autonomous regulation of the heart rate ander low atmospheric pressure

    Directory of Open Access Journals (Sweden)

    Наталія Михайлівна Волкова

    2015-11-01

    Full Text Available The role of beta1-adrenoreceptors at visual associative cortex in rats of different age in the impact on autonomous regulation of the heart rate ander low atmospheric pressure was investigated. The aim of the study was to check expediency of application nebivolol to prevent the adverse effects of hypoxic environment, the pressure conditions similar to the third type of weather.Methods. In the experimental group cardiointervalography recorded in the intact condition before hypoxia, after hypoxic exposure, after trepanation of the skull and applying the solution beta1-blocker nebivolol (0.5 mg / kg through the trepanation hole on the surface of the cerebral cortex (there were separate groups with right-sided and left-sided trepanation in projection of cortical areas Oc2L, with subsequent automatic analysis of data on a personal computer. In the control group a similar procedure of the experiment was carried out excepting hypoxic exposure. Effect of hypoxic atmosphere was created by reducing pressure by 50.76 hPa (0.05 atm in the Komovsky’s device and hold the anesthetized rat under a glass bell for 1 hour.Results. In juvenile, adult and old intact rats beta1-receptor structures in left and right associative cortical fields Oc2L are included to the neural circuits that provide growth of functional strenuousness in regulation of heart rhythm. After hypoxic exposure beta1-adrenoreceptors in the left field Oc2L are included in other neural circuits, and take part in limiting the functional strenuousness in regulation of heart rhythm.Conclusions. Experimental results about effectiveness of therapeutic doses of beta-1 adrenoblockers especially nebivolol in adult and old age for prevention of unfavorable effects of hypoxic medium that corresponds to the baric conditions of 111type weather are to be verified by the clinical observations

  7. Differences in blood pressure control and stroke mortality across Spain: the Prevención de Riesgo de Ictus (PREV-ICTUS) study.

    Science.gov (United States)

    Redón, Josep; Cea-Calvo, Luis; Lozano, José V; Martí-Canales, Juan C; Llisterri, José L; Aznar, Jose; González-Esteban, Jorge

    2007-04-01

    The objective was to assess the stroke risk and prevalence of the cardiovascular risk factors and to analyze their relationship with the specific stroke rates of mortality in each of the autonomic communities of Spain. We conducted a multicenter, cross-sectional study of population >60 years old in Spanish primary care centers. In all of the subjects, clinical, biochemical, and electrocardiographic data were obtained, and the 10-year stroke risk was calculated using the Framingham score. Mortality rates of stroke, age and sex adjusted, were obtained for each of the autonomic communities from the Ministry of Health. A total of 7343 subjects (mean age: 71.6 years, 53.4% women, 34.4% obese, and 27.1% diabetic subjects) were analyzed. A total of 73% were already diagnosed with hypertension. Among hypertensive subjects, 29.1% had blood pressure on therapeutic objective, and, of the total population, 35.7% had blood pressure under control. ECG-left ventricular hypertrophy was present in 12.9% of the subjects. The estimated stroke risk was 19.6%. Stroke mortality rates were significantly related to the estimated 10-year stroke risk (r=0.41; P<0.05) in each autonomic community. Poor hypertension control (P=-0.42; P<0.05) and prevalence of ECG-left ventricular hypertrophy (P=0.52; P<0.05) were the main factors related to the stroke mortality rates after controlling by age, sex, obesity, diabetes, and urban setting. Differences in stroke mortality throughout the autonomic communities of Spain were associated with indexes of worse blood pressure handling, low control rates, and high left-ventricular hypertrophy.

  8. Variations in battery life of a heart-lung machine using different pump speeds, pressure loads, boot material, centrifugal pump head, multiple pump usage, and battery age.

    LENUS (Irish Health Repository)

    Marshall, Cornelius

    2012-02-03

    Electrical failure during cardiopulmonary bypass (CPB) has previously been reported to occur in 1 of every 1500 cases. Most heart-lung machine pump consoles are equipped with built-in battery back-up units. Battery run times of these devices are variable and have not been reported. Different conditions of use can extend battery life in the event of electrical failure. This study was designed to examine the run time of a fully charged battery under various conditions of pump speed, pressure loads, pump boot material, multiple pump usage, and battery life. Battery life using a centrifugal pump also was examined. The results of this study show that battery life is affected by pump speed, circuit pressure, boot stiffness, and the number of pumps in service. Centrifugal pumps also show a reduced drain on battery when compared with roller pumps. These elements affect the longevity and performance of the battery. This information could be of value to the individual during power failure as these are variables that can affect the battery life during such a challenging scenario.

  9. Different Patterns of pfcrt and pfmdr1 Polymorphisms in P. falciparum Isolates from Nigeria and Brazil: The Potential Role of Antimalarial Drug Selection Pressure

    Science.gov (United States)

    Gbotosho, Grace O.; Folarin, Onikepe A.; Bustamante, Carolina; Pereira da Silva, Luis Hildebrando; Mesquita, Elieth; Sowunmi, Akintunde; Zalis, Mariano G.; Oduola, Ayoade M. J.; Happi, Christian T.

    2012-01-01

    The effect of antimalarial drug selection on pfcrt and pfmdr1 polymorphisms in Plasmodium falciparum isolates from two distinct geographical locations was determined in 70 and 18 P. falciparum isolates from Nigeria and Brazil, respectively, using nested polymerase chain reaction and direct DNA sequencing approaches. All isolates from Brazil and 72% from Nigeria harbored the mutant SVMNT and CVIET pfcrt haplotype, respectively. The pfcrt CVMNT haplotype was also observed in (7%) of the Nigerian samples. One hundred percent (100%) and 54% of the parasites from Brazil and Nigeria, respectively, harbored wild-type pfmdr1Asn86. We provide first evidence of emergence of the CVMNT haplotype in West Africa. The high prevalence of pfcrt CVIET and SVMNT haplotypes in Nigeria and Brazil, respectively, is indicative of different selective pressure by chloroquine and amodiaquine. Continuous monitoring of pfcrt SVMNT haplotype is required in endemic areas of Africa, where artesunate-amodiaquine combination is used for treatment of acute uncomplicated malaria. PMID:22302850

  10. A comparative effectiveness study of continuous positive airway pressure-related skin breakdown when using different nasal interfaces in the extremely low birth weight neonate.

    Science.gov (United States)

    Newnam, Katherine M; McGrath, Jacqueline M; Salyer, Jeanne; Estes, Tracy; Jallo, Nancy; Bass, W Thomas

    2015-02-01

    A three group prospective randomized experimental design was conducted to identify differences in frequency and severity of nasal injuries when comparing various interfaces used during continuous positive airway pressure (CPAP) and identified risk factors associated with injury. Seventy-eight neonates nasal prongs; continuous nasal mask; or alternating mask/prongs. Repeated measures ANOVA with Bonferroni correction demonstrated that significantly less skin injury was detected in the rotation interface group when compared to both mask and prong groups. In the final stepwise regression model (F = 11.51; R(2) = 0.221; p = 0.006) significant predictors of skin injury included number of days on nasal CPAP (p nasal injury was demonstrated using rotating mask/prong nasal interfaces. Future best practices must include precise selection of device size, developmental and CPAP device positioning with focused skin assessment including rapid intervention for skin injury. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Perceptions of Ethical Climate and Research Pressures in Different Faculties of a University: Cross-Sectional Study at the University of Split, Croatia.

    Science.gov (United States)

    Malički, Mario; Katavić, Vedran; Marković, Domagoj; Marušić, Matko; Marušić, Ana

    2017-10-25

    We determined the prevailing ethical climate at three different schools of a single university, in order to explore possible differences in the ethical climate related to different research fields: the School of Electrical Engineering, Mechanical Engineering, and Naval Architecture; the School of Humanities and Social Sciences; and the School of Medicine. We used the Ethical Climate Questionnaire to survey the staff (teachers and administration) at the three schools, and used the research integrity and organizational climate (RIOC) survey for early-stage researchers at the three schools. The dominant ethical climate type perceived collectively at the three university schools (response rate 49%, n = 294) was Laws and professional codes, which is associated with the cosmopolitan level of analysis and the ethical construct of principle. Individually, the same climate predominated at the schools for engineering and humanities, but the School of Medicine had the Self-interest ethical climate, which is associated with the individual level of analysis and the egoism ethical construct. In the RIOC survey (response rate 85%; n = 70), early-stage researchers from the three university schools did not differ in their perceptions of the organizational research integrity climate, or in their perceived individual, group or organizational pressures. Our study is the first, to the best of our knowledge, to show differences in perceived ethical climate at a medical school compared to other schools at a university. Further studies are needed to explore the reasons for these differences and how they translate to organizational outcomes, such as job satisfaction, commitment to the institution and dysfunctional behaviour, including research misconduct.

  12. Experimental blunt chest trauma--cardiorespiratory effects of different mechanical ventilation strategies with high positive end-expiratory pressure: a randomized controlled study.

    Science.gov (United States)

    Schreiter, Dierk; Carvalho, Nadja C; Katscher, Sebastian; Mende, Ludger; Reske, Alexander P; Spieth, Peter M; Carvalho, Alysson R; Beda, Alessandro; Lachmann, Burkhard; Amato, Marcelo B P; Wrigge, Hermann; Reske, Andreas W

    2016-01-12

    Uncertainty persists regarding the optimal ventilatory strategy in trauma patients developing acute respiratory distress syndrome (ARDS). This work aims to assess the effects of two mechanical ventilation strategies with high positive end-expiratory pressure (PEEP) in experimental ARDS following blunt chest trauma. Twenty-six juvenile pigs were anesthetized, tracheotomized and mechanically ventilated. A contusion was applied to the right chest using a bolt-shot device. Ninety minutes after contusion, animals were randomized to two different ventilation modes, applied for 24 h: Twelve pigs received conventional pressure-controlled ventilation with moderately low tidal volumes (VT, 8 ml/kg) and empirically chosen high external PEEP (16 cmH2O) and are referred to as the HP-CMV-group. The other group (n = 14) underwent high-frequency inverse-ratio pressure-controlled ventilation (HFPPV) involving respiratory rate of 65 breaths · min(-1), inspiratory-to-expiratory-ratio 2:1, development of intrinsic PEEP and recruitment maneuvers, compatible with the rationale of the Open Lung Concept. Hemodynamics, gas exchange and respiratory mechanics were monitored during 24 h. Computed tomography and histology were analyzed in subgroups. Comparing changes which occurred from randomization (90 min after chest trauma) over the 24-h treatment period, groups differed statistically significantly (all P values for group effect <0.001, General Linear Model analysis) for the following parameters (values are mean ± SD for randomization vs. 24-h): PaO2 (100% O2) (HFPPV 186 ± 82 vs. 450 ± 59 mmHg; HP-CMV 249 ± 73 vs. 243 ± 81 mmHg), venous admixture (HFPPV 34 ± 9.8 vs. 11.2 ± 3.7%; HP-CMV 33.9 ± 10.5 vs. 21.8 ± 7.2%), PaCO2 (HFPPV 46.9 ± 6.8 vs. 33.1 ± 2.4 mmHg; HP-CMV 46.3 ± 11.9 vs. 59.7 ± 18.3 mmHg) and normally aerated lung mass (HFPPV 42.8 ± 11.8 vs. 74.6 ± 10.0 %; HP-CMV 40.7 ± 8.6 vs. 53.4 ± 11.6%). Improvements occurring after recruitment in the HFPPV-group persisted

  13. Comparing the effects of 3 different pressure ulcer prevention support surfaces on the structure and function of heel and sacral skin: An exploratory cross-over trial.

    Science.gov (United States)

    Tomova-Simitchieva, Tsenka; Lichterfeld-Kottner, Andrea; Blume-Peytavi, Ulrike; Kottner, Jan

    2017-12-26

    Special support surfaces are key in pressure ulcer prevention. The aim of this study was to measure the effects of 3 different types of mattresses (reactive gel, active alternating air, basic foam) on skin properties of the sacral and heel skin after 2 hours loading. Fifteen healthy females (median age 66 years) were included. Transepidermal water loss, skin surface temperature, erythema, stratum corneum hydration, epidermal hydration, skin extensibility, elastic function, and recovery as well as skin roughness parameters were measured under controlled room conditions before loading, immediately after loading, and 20 minutes post-loading in the supine position on the different mattresses. The highest increases in transepidermal water loss, skin temperature, and erythema were observed for the foam mattress after loading, indicating higher deformation and occlusion. Cutaneous stiffness decreased in all 3 groups, indicating structural changes during loading. There was a substantial decrease of mean roughness at the heel skin in the foam group, leading to a flattening of the skin surface. Study results indicate that the type of support surface influences skin structure and function during loading. The gel and air mattress appeared to be more protective compared with the foam mattress, but the differences between the gel and air were minor. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  14. Changes in pulmonary artery pressure affect survival differently in lung transplant recipients who have pulmonary hypertension or chronic obstructive pulmonary disease.

    Science.gov (United States)

    O'Keefe, Kathryn L; Kilic, Ahmet; Pope-Harman, Amy; Hayes, Don; Kirkby, Stephen; Higgins, Robert S D; Whitson, Bryan A

    2014-08-01

    Pulmonary hypertension and right ventricular dysfunction can complicate lung transplant. Pulmonary artery pressures affect outcome are uncertain during wait list. We evaluated changes in wait list pulmonary artery pressures on survival after lung transplant. We queried the United Network for Organ Sharing/Standard Transplant Analysis and Research registry from 1987 to 2012 for all lung transplants. Recipients with unique pulmonary artery pressure measurements upon listing and transplant were included. Mean pulmonary artery pressure was rated as increased (increase > 5 mm Hg), decreased (decrease > 5 mm Hg), or unchanged (variation pulmonary artery pressure during the listing period (P ≤ .0001). In recipients with chronic obstructive pulmonary disease, survival was poorer when mean pulmonary artery pressure was increased than decreased (P ≤ .03). In recipients with primary pulmonary hypertension, survival was poorer when mean pulmonary artery pressure was decreased than increased (P ≤ .02). Proportional hazards analysis showed that increases in mean pulmonary artery pressure independently affected survival (hazard ratio, 0.78; 95% confidence interval, 0.62-0.96). Although the mechanism is unknown, an increase in mean pulmonary artery pressure in patients with chronic obstructive pulmonary disease is associated with poorer survival after lung transplant. In contrast, patients with primary pulmonary hypertension with decreased mean pulmonary artery pressure have poorer survival after lung transplant. In patients with primary pulmonary hypertension, changes in pulmonary artery pressure may be a surrogate for a failing right ventricular function. In chronic obstructive pulmonary disease, the change in pressure suggests an undetermined progressive process. Further study of right ventricular function is warranted to determine the effects of changes in pulmonary artery pressure on lung transplant recipients.

  15. A study on the physical fitness index, heart rate and blood pressure in different phases of lunar month on male human subjects.

    Science.gov (United States)

    Chakraborty, Ujjwal; Ghosh, Tusharkanti

    2013-09-01

    The gravitational pull of the moon on the earth is not the same in all phases of the lunar month, i.e. new moon (NM), first quarter (FQ), full moon (FM) and third quarter (TQ), and as a result the amplitude of tide differs in different phases. The gravitational pull of the moon may have effects on the fluid compartments of the human body and hence the cardiovascular system may be affected differentially in the different phases of the lunar month. In the present study resting heart rate (HR) and blood pressure (BP), physical fitness index (PFI), peak HR and BP immediately after step test, and recovery HR and BP after step test were measured during different phases of the lunar month in 76 male university students (age 23.7 ± 1.7 years). At rest, both systolic and mean arterial BP were ∼5 mmHg lower in NM and FM compared to FQ and TQ, but resting HR was not significantly different between phases. Further, peak HR and peak systolic BP after step test were lower (∼4 beat/min and ∼5 mmHg, respectively) in NM and FM compared to FQ and TQ. PFI was also higher (∼5) in NM and FM compared to FQ and TQ. Recovery of HR after step test was quicker in NM and FM compared to that of FQ and TQ. It appears from this study that gravitational pull of the moon may affect the cardiovascular functions of the human body. Moreover, the physical efficiency of humans is increased in NM and FM due to these altered cardiovascular regulations.

  16. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R

    2013-01-01

    Pressure vessels are closed containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They have a variety of applications in industry, including in oil refineries, nuclear reactors, vehicle airbrake reservoirs, and more. The pressure differential with such vessels is dangerous, and due to the risk of accident and fatality around their use, the design, manufacture, operation and inspection of pressure vessels is regulated by engineering authorities and guided by legal codes and standards. Pressure Vessel Design Manual is a solutions-focused guide to the many problems and technical challenges involved in the design of pressure vessels to match stringent standards and codes. It brings together otherwise scattered information and explanations into one easy-to-use resource to minimize research and take readers from problem to solution in the most direct manner possible. * Covers almost all problems that a working pressure vessel designer can expect to face, with ...

  17. Blood Pressure of Maintenance Hemodialysis Patients in the Dalmatian Region of Croatia: Differences between Hospital and Out-of-Hospital Dialysis Centers.

    Science.gov (United States)

    Gulin, Marijana; Klarić, Dragan; Ilić, Mario; Radić, Josipa; Kovačić, Vedran; Šain, Milenka

    2017-01-01

    This study was aimed at comparing the incidence of arterial hypertension and blood pressure (BP) variance in hospital and out-of-hospital hemodialysis (HD) patients during HD sessions. A cross-sectional study was conducted for 1 week at all the HD centers in Dalmatia, Croatia. The pre-, intra-, and post-dialysis BP values were collected for 3 consecutive HD sessions per patient. Of the 399 subjects, 73.9% were hypertensives, who showed higher interdialytic weight gain compared to the normotensives (2.58 vs. 2.40). Hospital and out-of-hospital HD patients received identical antihypertensive therapies, except that beta blockers were more frequently administered to out-of-hospital HD patients. Higher pre-, intra-, and post-dialysis BP values were recorded in patients at out-of-hospital HD centers. The differences in BP variability and antihypertensive therapies administered to hospital HD patients as compared to out-of-hospital HD patients may reflect differing approaches by the nephrologists at these centers. © 2017 S. Karger AG, Basel.

  18. Differing prognostic value of pulse pressure in patients with heart failure with reduced or preserved ejection fraction: results from the MAGGIC individual patient meta-analysis.

    Science.gov (United States)

    Jackson, Colette E; Castagno, Davide; Maggioni, Aldo P; Køber, Lars; Squire, Iain B; Swedberg, Karl; Andersson, Bert; Richards, A Mark; Bayes-Genis, Antoni; Tribouilloy, Christophe; Dobson, Joanna; Ariti, Cono A; Poppe, Katrina K; Earle, Nikki; Whalley, Gillian; Pocock, Stuart J; Doughty, Robert N; McMurray, John J V

    2015-05-07

    Low pulse pressure is a marker of adverse outcome in patients with heart failure (HF) and reduced ejection fraction (HF-REF) but the prognostic value of pulse pressure in patients with HF and preserved ejection fraction (HF-PEF) is unknown. We examined the prognostic value of pulse pressure in patients with HF-PEF [ejection fraction (EF) ≥ 50%] and HF-REF. Data from 22 HF studies were examined. Preserved left ventricular ejection fraction (LVEF) was defined as LVEF ≥ 50%. All-cause mortality at 3 years was evaluated in 27 046 patients: 22 038 with HF-REF (4980 deaths) and 5008 with HF-PEF (828 deaths). Pulse pressure was analysed in quintiles in a multivariable model adjusted for the previously reported Meta-Analysis Global Group in Chronic Heart Failure prognostic variables. Heart failure and reduced ejection fraction patients in the lowest pulse pressure quintile had the highest crude and adjusted mortality risk (adjusted hazard ratio 1.68, 95% confidence interval 1.53-1.84) compared with all other pulse pressure groups. For patients with HF-PEF, higher pulse pressure was associated with the highest crude mortality, a gradient that was eliminated after adjustment for other prognostic variables. Lower pulse pressure (especially <53 mmHg) was an independent predictor of mortality in patients with HF-REF, particularly in those with an LVEF < 30% and systolic blood pressure <140 mmHg. Overall, this relationship between pulse pressure and outcome was not consistently observed among patients with HF-PEF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  19. Do quiet standing centre of pressure measures within specific frequencies differ based on ability to recover balance in individuals with stroke?

    Science.gov (United States)

    Schinkel-Ivy, Alison; Singer, Jonathan C; Inness, Elizabeth L; Mansfield, Avril

    2016-06-01

    To determine whether quiet standing measures at specific frequency levels (representative of reactive control) differed between individuals with stroke based on their ability to recover balance (Failed or Successful Responses to external perturbations). Individuals with stroke completed a clinical assessment, including 30 s of quiet standing and lean-and-release postural perturbations, at admission to in-patient rehabilitation. Quiet standing centre of pressure (COP) signals were calculated and discrete wavelet decomposition was performed. Net COP amplitude, between-limb synchronization, and ratios of individual-limb COP were determined for each frequency level of interest, and for the non-decomposed signal (all frequency levels). Outcome measures were compared between individuals who exhibited Failed and Successful Responses during (a) unconstrained and (b) encouraged-use lean-and-release trials. Individuals with Failed Responses during the unconstrained lean-and-release trials displayed greater net COP amplitude than those with Successful Responses, specifically within a frequency range of 0.40-3.20Hz. Reduced ability to recover balance among individuals with stroke may be reflected in impaired reactive control of quiet standing. These results provide insight into the mechanism by which reactive control of quiet standing is impaired in individuals with stroke, and may inform assessment and rehabilitation strategies for post-stroke reactive balance control. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  20. Diabetic feet at risk: a new method of analysis of walking foot pressure images at different levels of neuropathy for early detection of plantar ulcers.

    Science.gov (United States)

    Prabhu, K G; Patil, K M; Srinivasan, S

    2001-05-01

    Studies were performed on a large number of diabetic patients with three levels of plantar sensation loss by analysing walking foot pressure images in the frequency domain. The feet of diabetic subjects were scanned over ten specified areas using Semmes-Weinstein's nylon monofilaments to determine quantitatively the three levels of neuropathy. A new parameter, the power ratio (PR, ratio of high frequency power to the total power in an image) was used to distinguish discretely between normal and diabetic feet in three levels of sensation loss. Analysis of results showed that the differences in PR values for diabetic feet (in all three levels of sensation loss) compared to normal feet were found to be highly significant (p<0.0005) in the areas of the foot where there was a high incidence of plantar ulcer formation, even at the early stage of neuropathy characterised by a sensation level of 45mN. This result could help in the early detection of plantar ulcer formation in the initial stage of sensation loss and may be utilised by orthopaedic surgeons to consider early corrective methods to protect these feet from further damage due to neuropathic ulcer formation.

  1. Effect of different single-session educational modalities on improving medical students' ability to demonstrate proper pressurized metered dose inhaler technique.

    Science.gov (United States)

    Dominelli, Giulio S; Dominelli, Paolo B; Rathgeber, Steven L; Webster, Sheila B

    2012-05-01

    Pressurized metered dose inhalers (pMDIs) remain important therapeutic options for obstructive lung diseases. The ability to instruct and evaluate inhaler technique is a crucial skill that all medical professionals should possess; unfortunately, many professionals lack proficiency with pMDIs. We aimed to determine if brief education interventions of differing modalities can positively affect medical students' skills over the long term. The baseline ability of medical students and first year residents to use pMDIs was scored via a 10-point scoring system. Students were randomized to receive no education, one-on-one instruction, or video instruction. Students were then retested immediately after the education and at the 3-month mark for retention of acquired skills. Video, one-on-one and the placebo groups modalities statistically improved the average medical student's score in the immediate retesting (7.5 and 7.4 vs. 4.7, p grades at the immediate recall significantly improved for both modalities. During retention testing, only video education had a statistically significant improvement in pass rate over the control group, as defined by an average score of 7 or better (8 vs. 1, p improve medical students' ability to use pMDIs in short-term testing. However, only video education retained significant improvement compared with control after 3 months. This suggests that compared with traditional one-on-one teaching, video education is an effective means of teaching medical students how to improve their pMDI technique.

  2. Simultaneous determination of 5 phenolic acids in fried Fructus xanthii from different production sites and its dispensing granules by using ultra-pressure liquid chromatography

    Science.gov (United States)

    Chen, Bin; Ma, Lihua; Wang, Xubo; Shen, Yuping; Jia, Xiaobin

    2013-01-01

    Background: To establish a ultra-pressure liquid chromatography (UPLC) method for the determination of 5 phenolic acids including neochlorogenic acid, chlorogenic acid, caffeic acid, cryptochlorogenic acid, and cynarin in fried Fructus xanthii from different production sites and its dispensing granule. Materials and Methods: An Acquity BEH C18 chromatographic column (100 mm × 2.1 mm,1.7 μm) was used to perform the determination, which was maintained at 40°C throughout the analysis. Mobile phase was composed of methanol and water containing 0.1% phosphoric acid (v/v) with flow rate at 0.4 mL/min under gradient elution, and detection wavelength was set to 325 nm for monitoring the separation. Results: Neochlorogenic acid, chlorogenic acid, caffeic acid, cryptochlorogenic acid, and cynarin have shown good linearity (r2≥0.9997) within 0.959–239.75, 0.9408–235.2, 0.1638–40.95, 0.6744–67.44, and 0.47–117.5 μg/mL, and their average recoveries were 100.09%, 99.98%, 101.74%, 99.83%, and 99.63%, respectively. Conclusion: The UPLC method established in this study was rapid, and of good accuracy, repeatability and resolution, and hence can assist in the control quality of fried Fructus xanthii as well as its dispensing granule in an efficient manner. PMID:23772104

  3. Effects of L-Arginine Supplementation on Blood Pressure Reduction Pre-, Peri-, and Post-Cardiovascular Stimulus in Hypertensive Subjects with Different Angiotensin-Converting-Enzyme Genotypes

    Directory of Open Access Journals (Sweden)

    Malfatti Carlos Ricardo Maneck

    2014-08-01

    Full Text Available Purpose. The present study investigated whether L-arginine supplementation reduces blood pressure (BP in hypertensive subjects with different ACE genotypes. Methods. Eight male hypertensive patients received L-arginine (2 or 4 g/day or a placebo for a period of 4 days prior an exercise test. Statistical analysis consisted of one-way analysis of variance. Results. L-arginine supplementation induced a statistically significant (p ⋋ 0.05 reduction in systolic BP measured during rest (reductions of 7.8% and 12.3% with 2 and 4 g/day, respectively, exercise (reductions of 11.8% and 10.4% with 2 and 4 g/day, respectively, and recovery (reductions of 11.7% and 10.7% with 2 and 4 g/day, respectively. The observed magnitude of BP reduction suggests an association with ACE polymorphism; a larger effect was seen with the II and DI genotypes compared with the DD genotype (II: 121 mmHg and DI: 133 mmHg vs. DD: 144 mmHg. Conclusions. The results showed that L-arginine supplementation at low doses was efficient in reducing BP and that vasodilator actions that occurred through the secretion of nitric oxide might be ACE genotype dependent.

  4. Preliminary investigation on the reduction of plantar loading pressure with different insole materials (SRP--Slow Recovery Poron, P--Poron, PPF--Poron +Plastazote, firm and PPS--Poron+Plastazote, soft).

    Science.gov (United States)

    Tong, Jasper W K; Ng, Eddie Y K

    2010-03-01

    The aim of this study is to investigate the amount of pressure reduction for different padding and insole materials commonly used in the podiatry clinic. Plantar pressure were taken for 5 subjects without insoles fitted (BF) in their daily sports shoes, and thereafter with 4 pairs of simple insoles (6.4 mm thick) each as follow: SRP - Slow Recovery Poron, P - Poron, PPF - Poron+Plastazote (firm) and PPS - Poron+Plastazote (soft). In addition, subjects were also tested with semi-compressed felt (SCF) padding with a 1st metatarsophalangeal joint (MTPJ) aperture cut-out bilaterally. Minimum, maximum, mean pressure and peak pressure at the hallux, 1st, 2nd, 3rd/4th and 5th MTPJ across both feet were analysed. Repeated measures ANOVA with post hoc Bonferroni paired wise comparison was used to test for any statistical significance at the 95% confidence level for all pressure data. PPF was significant in reducing the minimum (p<0.005) and mean pressure (p<0.03) when compared to BF. This accounted for approximately 28% and 27% pressure reduction in minimum and mean pressure respectively. Peak pressure on the 1st MTPJ locality showed significant reduction of 37% and 29% with the use of SCF (p<0.004) and PPF (p<0.004), respectively. All 4 commonly used insole materials were able to reduce pressure across the whole foot with PPF achieving significance. Off-loading the 1st MTPJ would still be best achieved with the commonly used plantar metatarsal pad of SCF with the aperture cut-out design. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  5. Effects of blood-pressure-lowering treatment on outcome incidence in hypertension: 10 - Should blood pressure management differ in hypertensive patients with and without diabetes mellitus? Overview and meta-analyses of randomized trials.

    Science.gov (United States)

    Thomopoulos, Costas; Parati, Gianfranco; Zanchetti, Alberto

    2017-05-01

    Type 2 diabetes mellitus is associated with an increased risk of hypertension, and cardiovascular and renal disease, and it has been recommended that management of hypertension should be more aggressive in presence than in absence of diabetes mellitus, but the matter is controversial at present. Meta-analysing all available randomized controlled trials (RCTs) to compare the effects on cardiovascular and renal outcomes of blood pressure BP lowering to different systolic BP (SBP) and diastolic BP (DBP) levels or by different drug classes in patients with and without diabetes mellitus. The database consisted of 72 BP-lowering RCTs (260 210 patients) and 50 head-to-head drug comparison RCTs (247 006). Among these two sets, RCTs or RCT subgroups separately reporting data from patients with and without diabetes mellitus were identified, and stratified by in-treatment achieved SBP and DBP, by drug class compared with placebo, and drug class compared with all other classes. Risk ratios and 95% confidence intervals, and absolute risk reductions of six fatal and non-fatal cardiovascular outcomes, all-cause death, and end-stage renal disease (ESRD) were calculated (random-effects model) separately for diabetes mellitus and no diabetes mellitus, and compared by interaction analysis. We identified 41 RCTs providing data on 61 772 patients with diabetes mellitus and 40 RCTs providing data on 191 353 patients without diabetes mellitus. For achieved SBP at least 140 mmHg, relative and absolute reductions of most cardiovascular outcomes were significantly greater in diabetes mellitus than no diabetes mellitus, whereas for achieved SBP below 130 mmHg, the difference disappeared or reversed (greater outcome reduction in no diabetes mellitus). Significant ESRD reduction was found only in diabetes mellitus, but it was greatest when achieved SBP was at least 140 mmHg, and no further effect was found at SBP below 140 mmHg. All antihypertensive drug classes reduced

  6. Pressure Sores

    Science.gov (United States)

    Pressure sores are areas of damaged skin caused by staying in one position for too long. They ... wheelchair, or are unable to change your position. Pressure sores can cause serious infections, some of which ...

  7. Investigating differences in the root to shoot transfer and xylem sap solubility of organic compounds between zucchini, squash and soybean using a pressure chamber method.

    Science.gov (United States)

    Garvin, Naho; Doucette, William J; White, Jason C

    2015-07-01

    A pressure chamber method was used to examine differences in the root to shoot transfer and xylem sap solubility of caffeine (log Kow=-0.07), triclocarban (log Kow=3.5-4.2) and endosulfan (log Kow=3.8-4.8) for zucchini (cucurbita pepo ssp pepo), squash (cucurbita pepo ssp ovifera), and soybean (glycine max L.). Transpiration stream concentration factors (TSCF) for caffeine (TSCF=0.8) were statistically equivalent for all plant species. However, for the more hydrophobic endosulfan and triclocarban, the TSCF values for zucchini (TSCF=0.6 and 0.4, respectively) were 3 and 10 times greater than the soybean and squash (TSCF=0.2 and 0.05, respectively). The difference in TSCF values was examined by comparing the measured solubilities of caffeine, endosulfan and triclocarban in deionized water to those in soybean and zucchini xylem saps using a modified shake flask method. The measured solubility of organic contaminants in xylem sap has not previously been reported. Caffeine solubilities in the xylem saps of soybean and zucchini were statistically equal to deionized water (21500mgL(-1)) while endosulfan and triclocarban solubilities in the zucchini xylem sap were significantly greater (0.43 and 0.21mgL(-1), respectively) than that of the soybean xylem sap (0.31 and 0.11mgL(-1), respectively) and deionized water (0.34 and 0.11mgL(-1), respectively). This suggests that the enhanced root to shoot transfer of hydrophobic organics reported for zucchini is partly due to increased solubility in the xylem sap. Further xylem sap characterization is needed to determine the mechanism of solubility enhancement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery

    Directory of Open Access Journals (Sweden)

    C.B.F. Pantoni

    2011-01-01

    Full Text Available The application of continuous positive airway pressure (CPAP produces important hemodynamic alterations, which can influence breathing pattern (BP and heart rate variability (HRV. The aim of this study was to evaluate the effects of different levels of CPAP on postoperative BP and HRV after coronary artery bypass grafting (CABG surgery and the impact of CABG surgery on these variables. Eighteen patients undergoing CABG were evaluated postoperatively during spontaneous breathing (SB and application of four levels of CPAP applied in random order: sham (3 cmH2O, 5 cmH2O, 8 cmH2O, and 12 cmH2O. HRV was analyzed in time and frequency domains and by nonlinear methods and BP was analyzed in different variables (breathing frequency, inspiratory tidal volume, inspiratory and expiratory time, total breath time, fractional inspiratory time, percent rib cage inspiratory contribution to tidal volume, phase relation during inspiration, phase relation during expiration. There was significant postoperative impairment in HRV and BP after CABG surgery compared to the preoperative period and improvement of DFAα1, DFAα2 and SD2 indexes, and ventilatory variables during postoperative CPAP application, with a greater effect when 8 and 12 cmH2O were applied. A positive correlation (P < 0.05 and r = 0.64; Spearman was found between DFAα1 and inspiratory time to the delta of 12 cmH2O and SB of HRV and respiratory values. Acute application of CPAP was able to alter cardiac autonomic nervous system control and BP of patients undergoing CABG surgery and 8 and 12 cmH2O of CPAP provided the best performance of pulmonary and cardiac autonomic functions.

  9. Pressure Controller

    Science.gov (United States)

    1981-01-01

    EPIC is Electronic Pressure Indicating Controller produced by North American Manufacturing Company. It is a high-sensitivity device for improving combustion efficiency in industrial furnaces that interprets a signal from a pressure transducer on a furnace and regulates furnace pressure accordingly. A controller can provide savings of from five to 25 percent of an industrial user's annual furnace fuel bill.

  10. Intracranial Pressure

    DEFF Research Database (Denmark)

    Hvedstrup, Jeppe; Radojicic, Aleksandra; Moudrous, Walid

    2018-01-01

    OBJECTIVE: To compare a new method of noninvasive intracranial pressure (nICP) measurement with conventional lumbar puncture (LP) opening pressure. METHODS: In a prospective multicenter study, patients undergoing LP for diagnostic purposes underwent intracranial pressure measurements with HeadSen...

  11. Convective heat transfer and pressure drop of aqua based TiO2 nanofluids at different diameters of nanoparticles: Data analysis and modeling with artificial neural network

    Science.gov (United States)

    Hemmat Esfe, Mohammad; Nadooshan, Afshin Ahmadi; Arshi, Ali; Alirezaie, Ali

    2018-03-01

    In this study, experimental data related to the Nusselt number and pressure drop of aqueous nanofluids of Titania is modeled and estimated by using ANN with 2 hidden layers and 8 neurons in each layer. Also in this study the effect of various effective variables in the Nusselt number and pressure drop is surveyed. This study indicated that the neural network modeling has been able to model experimental data with great accuracy. The modeling regression coefficient for the data of Nusselt number and relative pressure drop is 99.94% and 99.97% respectively. Besides, it represented that the increment of the Reynolds number and concentration made the increment of Nusselt number and pressure drop of aqueous nanofluid.

  12. Laser-induced damage threshold of ZrO2 thin films prepared at different oxygen partial pressures by electron-beam evaporation

    International Nuclear Information System (INIS)

    Zhang Dongping; Shao Jianda; Zhao Yuanan; Fan Shuhai; Hong Ruijing; Fan Zhengxiu

    2005-01-01

    ZrO 2 films were deposited by electron-beam evaporation with the oxygen partial pressure varying from 3x10 -3 Pa to 11x10 -3 Pa. The phase structure of the samples was characterized by x-ray diffraction (XRD). The thermal absorption of the films was measured by the surface thermal lensing technique. A spectrophotometer was employed to measure the refractive indices of the samples. The laser-induced damage threshold (LIDT) was assessed using a 1064 nm Nd: yttritium-aluminum-garnet pulsed laser at pulse width of 12 ns. The influence of oxygen partial pressure on the microstructure and LIDT of ZrO 2 films was investigated. XRD data revealed that the films changed from polycrystalline to amorphous as the oxygen partial pressure increased. The variation of refractive index at 550 nm wavelength indicated that the packing density of the films decreased gradually with increasing oxygen partial pressure. The absorptance of the samples decreased monotonically from 125.2 to 84.5 ppm with increasing oxygen partial pressure. The damage threshold values increased from 18.5 to 26.7 J/cm 2 for oxygen partial pressures varying from 3x10 -3 Pa to 9x10 -3 Pa, but decreased to 17.3 J/cm 2 in the case of 11x10 -3 Pa

  13. Reliability of Center of Pressure Parameters in Postural Sway among Athlete and Non-athlete Men in Different Levels of Fatigue and Vision

    Directory of Open Access Journals (Sweden)

    Zohreh Meshkati

    2010-10-01

    Full Text Available Objective: This study aimed to investigate the skill, fatigue and vision-related differences between athletes and non-athletes in reliability of center of pressure (COP measures derived from force platform. Materials & Methods: Thirty-one healthy male participants (15 athletes and 16 non-athletes were tested on force platform on two sessions with a 48-72 hr interval. COP parameters was recorded during two-legged quiet standing before and after a generalized fatigue exercise by treadmill, with eyes-open (EO and eyes-closed (EC. Standard deviation (SD of amplitude, SD of velocity in anteroposterior (AP and mediolateral directions and mean total velocity were calculated from 30 sec COP data. Results: Higher intraclass correlation coefficient (ICC was found for COP measures in the athlete (compared with the non-athlete group. ICC was increased in post-fatigue (compared with pre-fatigue conditions. Also higher ICC was found for EC (compared with EO tests. Coefficients of variation smaller than 15% were obtained for most of the COP measures. Alpha level of 0. 05 was considered for all statistical analyses. Regarding the level of skill, fatigue and vision, mean total velocity (P=0. 001 and SD of velocity (AP (P=0. 001 were the most reliable parameters. Conclusion: The results aid researchers in selection of reliable COP measures for future studies of postural control in sports. In this way, researchers can use mean total velocity and SD of velocity (AP parameters in their studies in same conditions on athletes.

  14. A Simultaneous Analytical Method to Profile Non-Volatile Components with Low Polarity Elucidating Differences Between Tobacco Leaves Using Atmospheric Pressure Chemical Ionization Mass Spectrometry Detection

    Directory of Open Access Journals (Sweden)

    Ishida Naoyuki

    2016-04-01

    Full Text Available A comprehensive analytical method using liquid chromatography atmospheric pressure chemical ionization mass spectrometry detector (LC/APCI-MSD was developed to determine key non-volatile components with low polarity elucidating holistic difference among tobacco leaves. Nonaqueous reversed-phase chromatography (NARPC using organic solvent ensured simultaneous separation of various components with low polarity in tobacco resin. Application of full-scan mode to APCI-MSD hyphenated with NARPC enabled simultaneous detection of numerous intense product ions given by APCI interface. Parameters for data processing to filter, feature and align peaks were adjusted in order to strike a balance between comprehensiveness and reproducibility in analysis. 63 types of components such as solanesols, chlorophylls, phytosterols, triacylglycerols, solanachromene and others were determined on total ion chromatograms according to authentic components, wavelength spectrum and mass spectrum. The whole area of identified entities among the ones detected on total ion chromatogram reached to over 60% and major entities among those identified showed favorable linearity of determination coefficient of over 0.99. The developed method and data processing procedure were therefore considered feasible for subsequent multivariate analysis. Data matrix consisting of a number of entities was then subjected to principal component analysis (PCA and hierarchical clustering analysis. Cultivars of tobacco leaves were distributed far from each cultivar on PCA score plot and each cluster seemed to be characterized by identified non-volatile components with low polarity. While fluecured Virginia (FCV was loaded by solanachromene, phytosterol esters and triacylglycerols, free phytosterols and chlorophylls loaded Burley (BLY and Oriental (ORI respectively. Consequently the whole methodology consisting of comprehensive method and data processing procedure proved useful to determine key

  15. Roles of PI3K and JAK pathways in viability of retinal ganglion cells after acute elevation of intraocular pressure in rats with different autoimmune backgrounds

    Directory of Open Access Journals (Sweden)

    Wang Ningli

    2008-08-01

    Full Text Available Abstract Background We recently showed that whereas inhibition of PI3K/akt or JAK/STAT pathway promoted retinal ganglion cell (RGC survival after optic nerve (ON injury in Fischer 344 (F344 rats, the same inhibition resulted in aggravated RGC loss after acute intraocular pressure (IOP elevation in Sprague Dawley (SPD rats. In addition, the responses of macrophages to ON injury and acute IOP elevation were different between F344 and Lewis rats, i.e., different autoimmune profiles. Using an acute IOP elevation paradigm in this study, we investigated 1 whether autoimmune background influences PI3K/akt and JAK/STAT functions by examining the effect of PI3K/akt and JAK/STAT pathway inhibition on RGC survival in F344 and Lewis rats, and 2 whether differential actions of macrophages occur in PI3K/akt and JAK/STAT pathways-dependent modulation of RGC survival. IOP elevation was performed at 110 mmHg for 2 hours. PI3K/akt and JAK/STAT pathway inhibitors were applied intravitreally to block their respective pathway signaling transduction. Because macrophage invasion was seen in the eye after the pathway inhibition, to examine the role of these pathways independent of macrophages, macrophages in the retina were removed by intravitreal application of clodronate liposomes. Viable RGCs were retrogradely labelled by FluoroGold 40 hours before animal sacrifice. Results Similar to what was previously observed, significantly more RGCs were lost in Lewis than F344 rats 3 weeks after acute IOP elevation. As in SPD rats, inhibition of the PI3K/akt or JAK/STAT pathway increased the loss of RGCs in both F344 and Lewis rats. Removal of macrophages in the eye by clodronate liposomes reduced RGC loss due to pathway inhibition in both strains. Conclusion This study demonstrates that following acute IOP elevation 1 PI3K/akt and JAK/STAT pathways mediate RGC survival in both F344 and Lewis rats, 2 autoimmune responses do not influence the functions of these two pathways

  16. Isosteric Vapor Pressure – Temperature Data for Water Sorption in Hardened Cement Paste: Enthalpy, Entropy and Sorption Isotherms at Different Temperatures

    DEFF Research Database (Denmark)

    Radjy, Fariborz; Sellevold, Erik J.; Hansen, Kurt Kielsgaard

    PART I: In order to generate isosteric (constant mass) vapor pressure – temperature data (P-T data) for adsorbed pore water in hydrated cement paste, the Thermo Piestic Analysis system (the TPA system) described herein was developed. The TPA system generates high precision equilibrium isosteric P....... The accuracies for pressure, enthalpy and entropy are found to be 0.5% or less. PART II: The TPA-system has been used to generate water vapor pressure – temperature data for room temperature – and steam cured hardened cement pastes as well as porous vycor glass. The moisture contents range from saturated to dry......-T data automatically during slow heating and cooling. The generated data are subjected to regression analysis leading to very close curve fitting of the P-T data and enabling appropriate enthalpy and entropy computations. The TPA system's absolute accuracy is checked by generating P-T data for pure water...

  17. Constraining the Depth of a Martian Magma Ocean through Metal-Silicate Partitioning Experiments: The Role of Different Datasets and the Range of Pressure and Temperature Conditions

    Science.gov (United States)

    Righter, K.; Chabot, N.L.

    2009-01-01

    Mars accretion is known to be fast compared to Earth. Basaltic samples provide a probe into the interior and allow reconstruction of siderophile element contents of the mantle. These estimates can be used to estimate conditions of core formation, as for Earth. Although many assume that Mars went through a magma ocean stage, and possibly even complete melting, the siderophile element content of Mars mantle is consistent with relatively low pressure and temperature (PT) conditions, implying only shallow melting, near 7 GPa and 2073 K. This is a pressure range where some have proposed a change in siderophile element partitioning behavior. We will examine the databases used for parameterization and split them into a low and higher pressure regime to see if the methods used to reach this conclusion agree for the two sets of data.

  18. In shoe pressure measurements during different motor tasks while wearing safety shoes: The effect of custom made insoles vs. prefabricated and off-the-shelf.

    Science.gov (United States)

    Caravaggi, Paolo; Giangrande, Alessia; Lullini, Giada; Padula, Giuseppe; Berti, Lisa; Leardini, Alberto

    2016-10-01

    Health and safety regulations in many countries require workers at risk to wear safety shoes in a factory environment. These shoes are often heavy, rigid, and uncomfortable. Wearing safety shoes daily leads to foot problems, discomfort and fatigue, resulting also in the loss of numerous working days. Currently, knowledge of the biomechanical effects of insoles in safety shoes, during working activities, is very limited. Seventeen workers from a metalworking factory were selected and clinically examined for any foot conditions. Workers feet were 3D scanned, with regards to their plantar view, and the images used to design 34 custom-insoles, based on foot and safety shoe models. Three insoles were blind-tested by each worker: custom (CUS); prefabricated with the safety-shoe (PSS), and off-the-shelf (OTS). Foot-to-insole pressure distribution was measured in seven motor tasks replicating typical working activities: single and double-leg standing; weight lifting; stair ascending and descending; normal and fast walking. Wearing CUS within safety shoes resulted in a greater uniform pressure distribution across plantar regions for most of the working activities. Peak pressure at the forefoot during normal walking was the lowest in the custom insole (CUS 275.9±55.3kPa; OTS 332.7±75.5kPa; PSS 304.5±54.2kPa). Normal and fast walking were found to be the most demanding activities in terms of peak pressure. Wearing safety shoes results in high pedobarographic parameters in several foot regions. The use of custom insoles designed on the foot morphology helps decrease peak pressure and pressure-time integral compared to prefabricated featureless insoles. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Critical cerebral perfusion pressure at high intracranial pressure measured by induced cerebrovascular and intracranial pressure reactivity.

    Science.gov (United States)

    Bragin, Denis E; Statom, Gloria L; Yonas, Howard; Dai, Xingping; Nemoto, Edwin M

    2014-12-01

    The lower limit of cerebral blood flow autoregulation is the critical cerebral perfusion pressure at which cerebral blood flow begins to fall. It is important that cerebral perfusion pressure be maintained above this level to ensure adequate cerebral blood flow, especially in patients with high intracranial pressure. However, the critical cerebral perfusion pressure of 50 mm Hg, obtained by decreasing mean arterial pressure, differs from the value of 30 mm Hg, obtained by increasing intracranial pressure, which we previously showed was due to microvascular shunt flow maintenance of a falsely high cerebral blood flow. The present study shows that the critical cerebral perfusion pressure, measured by increasing intracranial pressure to decrease cerebral perfusion pressure, is inaccurate but accurately determined by dopamine-induced dynamic intracranial pressure reactivity and cerebrovascular reactivity. Cerebral perfusion pressure was decreased either by increasing intracranial pressure or decreasing mean arterial pressure and the critical cerebral perfusion pressure by both methods compared. Cortical Doppler flux, intracranial pressure, and mean arterial pressure were monitored throughout the study. At each cerebral perfusion pressure, we measured microvascular RBC flow velocity, blood-brain barrier integrity (transcapillary dye extravasation), and tissue oxygenation (reduced nicotinamide adenine dinucleotide) in the cerebral cortex of rats using in vivo two-photon laser scanning microscopy. University laboratory. Male Sprague-Dawley rats. At each cerebral perfusion pressure, dopamine-induced arterial pressure transients (~10 mm Hg, ~45 s duration) were used to measure induced intracranial pressure reactivity (Δ intracranial pressure/Δ mean arterial pressure) and induced cerebrovascular reactivity (Δ cerebral blood flow/Δ mean arterial pressure). At a normal cerebral perfusion pressure of 70 mm Hg, 10 mm Hg mean arterial pressure pulses had no effect on

  20. The effects of a pressure extraction system on quality the parameters of different virgin pistachio (Pistacia vera L. var. Larnaka oils

    Directory of Open Access Journals (Sweden)

    Pardo, J. E.

    2012-09-01

    Full Text Available Pistachios are a good source for oil extraction as they are rich in unsaturated fatty acids and other bioactive components like polyphenols and phenolic compounds. The yield and quality parameters of the oil extracted from four batches of pistachios with different sizes were analyzed. Two different pressure systems (screw press and hydraulic press were used for oil extraction. The yield was higher when the screw press was used, especially when the highest quality pistachios (larger pistachios were used to extract the oil (40 ± 2.12%. With the hydraulic press, the yield was around 30% for all pistachio types. The color of the oils extracted with the screw press was darker than the oil extracted with the hydraulic press in all types of pistachios used. No significant differences were found in the acidity, K270, and K232 values when high quality pistachios were used. When lower quality pistachios (smaller pistachios were used, the values of these three parameters increased in comparison with larger pistachios. On the other hand, oil samples from lower quality pistachios obtained by the screw press showed the highest values. The oxidative stability was higher in the samples of oil from high quality pistachios, with no differences in regard to the extraction system. When lower quality pistachios were used, the oxidative stability was significantly lower.El pistacho es una magnífica fuente de aceite, puesto que a su alto contenido en materia grasa se añaden una elevada proporción de ácidos grasos insaturados y otros compuestos bioactivos como los polifenoles o los compuestos fenólicos. Se ha analizado el rendimiento y los parámetros de calidad del aceite extraído de cuatro tipos de pistacho de diferente calidad, usando dos tipos de prensas (hidráulica y de tornillo. El rendimiento de la extracción fue mayor cuando se empleó la prensa de tornillo, especialmente cuando los pistachos de mayor calidad (pistachos más grandes se emplearon para

  1. Pressure ulcers.

    Science.gov (United States)

    Reddy, Madhuri

    2011-04-28

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of preventive interventions in people at risk of developing pressure ulcers? What are the effects of treatments in people with pressure ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 64 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: air-filled vinyl boots, air-fluidised supports, alternating-pressure surfaces (including mattresses), alternative foam mattresses, constant low-pressure supports, debridement, electric profiling beds, electrotherapy, hydrocellular heel supports, low-air-loss beds (including hydrotherapy beds), low-level laser therapy, low-tech constant-low-pressure supports, medical sheepskin overlays, nutritional supplements, orthopaedic wool padding, pressure-relieving overlays on operating tables, pressure-relieving surfaces, repositioning (regular "turning"), seat cushions, standard beds, standard care, standard foam mattresses, standard tables, surgery, therapeutic ultrasound, topical lotions and

  2. Differences in Blood Pressure in Infants After General Anesthesia Compared to Awake Regional Anesthesia (GAS Study-A Prospective Randomized Trial)

    NARCIS (Netherlands)

    McCann, Mary Ellen; Withington, D E; Arnup, S J; Davidson, A J; Disma, N; Frawley, G; Morton, N S; Bell, G; Hunt, R W; Bellinger, D C; Polaner, D M; Leo, A; Absalom, A R; von Ungern-Sternberg, B S; Izzo, F; Szmuk, P; Young, V; Soriano, S G; de Graaff, J C

    BACKGROUND: The General Anesthesia compared to Spinal anesthesia (GAS) study is a prospective randomized, controlled, multisite, trial designed to assess the influence of general anesthesia (GA) on neurodevelopment at 5 years of age. A secondary aim obtained from the blood pressure data of the GAS

  3. Silicon pressure transducers: a review

    International Nuclear Information System (INIS)

    Aceves M, M.; Sandoval I, F.

    1994-01-01

    We present a review of the pressure sensors, which use the silicon piezo resistive effect and micro machining technique. Typical pressure sensors, applications, design and other different structures are presented. (Author)

  4. Blood Pressure Elevation Associated with Topical Prostaglandin F2α Analogs: An Analysis of the Different Spontaneous Adverse Event Report Databases.

    Science.gov (United States)

    Ohyama, Katsuhiro; Kawakami, Haruna; Inoue, Michiko

    2017-01-01

    Topical prostaglandin F2α (PGF2α) analogs are widely used as the first line of therapy for glaucoma. Systemic PGF2α is suggested to increase blood pressure. Some ophthalmic formulations with β-receptor blocking or α-receptor stimulating actions are reported to cause systemic adverse events such as a decrease in heart rate and blood pressure. The objective of this study was to evaluate the association between topical PGF2α analogs and blood pressure elevation. We analyzed the reports obtained from the Food and Drug Administration Adverse Event Reporting System (FAERS) database from the first quarter of 2004 until the end of 2015 and the Japanese Adverse Drug Event Report (JADER) database from April 2004 to January 2016 for signal detection using reporting odds ratio (ROR), a method of disproportionality analyses. Signals are considered significant if the ROR estimates and lower bound of the 95% confidence interval (CI) exceed 1. Preferred terms in the Medical Dictionary for Regulatory Activities were utilized to define blood pressure elevation. A total of 6156081 reports from the FAERS and 351226 reports from the JADER were analyzed. The significant RORs with 95% CI were calculated to be 1.82 (95% CI: 1.55-2.13) for bimatoprost, 1.69 (95% CI: 1.53-1.85) for latanoprost, and 2.17 (95% CI: 1.82-2.59) for travoprost from the FAERS. From the JADER, 5.01 (95% CI: 1.59-15.8) was calculated for bimatoprost and 8.02 (95% CI: 2.94-21.9) for tafluprost. The resulting data suggest the necessity for further clinical research on blood pressure elevation associated with topical PGF2α analogs and close monitoring.

  5. Protocol for Past BP: a randomised controlled trial of different blood pressure targets for people with a history of stroke of transient ischaemic attack (TIA in primary care

    Directory of Open Access Journals (Sweden)

    Greenfield Sheila

    2010-08-01

    Full Text Available Abstract Background Blood pressure (BP lowering in people who have had a stroke or transient ischaemic attack (TIA leads to reduced risk of further stroke. However, it is not clear what the target BP should be, since intensification of therapy may lead to additional adverse effects. PAST BP will determine whether more intensive BP targets can be achieved in a primary care setting, and whether more intensive therapy is associated with adverse effects on quality of life. Methods/Design This is a randomised controlled trial (RCT in patients with a past history of stroke or TIA. Patients will be randomised to two groups and will either have their blood pressure (BP lowered intensively to a target of 130 mmHg systolic, (or by 10 mmHg if the baseline systolic pressure is between 125 and 140 mmHg compared to a standard group where the BP will be reduced to a target of 140 mmHg systolic. Patients will be managed by their practice at 1-3 month intervals depending on level of BP and followed-up by the research team at six monthly intervals for 12 months. 610 patients will be recruited from approximately 50 general practices. The following exclusion criteria will be applied: systolic BP The primary outcome will be change in systolic BP over twelve months. Secondary outcomes include quality of life, adverse events and cardiovascular events. In-depth interviews with 30 patients and 20 health care practitioners will be undertaken to investigate patient and healthcare professionals understanding and views of BP management. Discussion The results of this trial will inform whether intensive blood pressure targets can be achieved in people who have had a stroke or TIA in primary care, and help determine whether or not further research is required before recommending such targets for this population. Trial Registration ISRCTN29062286

  6. Difference between supine and upright blood pressure associates to the efficacy of midodrine on postural orthostatic tachycardia syndrome (POTS) in children.

    Science.gov (United States)

    Deng, Wenjun; Liu, Yanling; Liu, Angie Dong; Holmberg, Lukas; Ochs, Todd; Li, Xueying; Yang, Jinyan; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2014-04-01

    Postural orthostatic tachycardia syndrome (POTS) is common, and has a serious impact on children's quality of life. Midodrine hydrochloride, an α1-adrenoreceptor agonist, is an effective treatment. The study was designed to examine the therapeutic efficacy of midodrine hydrochloride by quantifying changes in blood pressure during the head-up test (HUT), in children with POTS. Overall, 104 out of 110 children with POTS were treated with midodrine hydrochloride and successfully followed-up. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) changes were analyzed during the HUT. In a retrospective analysis, a receiver operating characteristic (ROC) curve was used to analyze the therapeutic predictive value of pre-treatment changes in SBP, DBP, and a combination of both, from the supine position to standing, in the subjects. The increase of SBP and DBP from the supine position to standing in responders were significantly lower than that of the non-responders. The ROC curve showed that midodrine hydrochloride for children with POTS would be predicted to be effective when the pre-treatment increase of SBP was ≤ 0 mmHg, or when the pre-treatment increase of DBP was ≤ 6.5 mmHg (from the supine position to standing), yielding a sensitivity of 72% and specificity of 88%. The area under the curve was 0.744 and 0.809, respectively. Hence, the results suggested that looking at the changes in blood pressure during the HUT was useful in predicting the response to midodrine hydrochloride in children with POTS.

  7. Effects of alpha,beta-blocker, arotinolol chloride, on 24-h blood pressure--difference between elderly and younger hypertensive patients.

    Science.gov (United States)

    Kuwajima, I; Suzuki, Y; Otsuka, K; Kawamura, H; Kuramoto, K

    1993-08-01

    To assess the effect of age on the circadian blood pressure (BP) after an alpha,beta-adrenergic blocker, the ambulatory BP was measured before and after arotinolol chloride administration in nine younger (mean age 49.1 years) and 14 older (72.1 years) patients with essential hypertension. After a 4-week control period, arotinolol chloride was administered twice daily (08:00 and 20:00 hours) for 8 weeks and the ambulatory BP was measured non-invasively at the end of the control and treatment period. Arotinolol significantly reduced the daytime systolic BP from 152.3 to 140.9 mmHg (P arotinolol during the day and night. Night-time reduction of BP was significantly less in the older group (-8.6 vs -15.1 mmHg for the systolic pressure P < 0.01; -5.8 vs -9.8 mmHg for the diastolic pressure P < 0.01).

  8. Evaluation of clinical efficacy and safety of cervical trauma collars: differences in immobilization, effect on jugular venous pressure and patient comfort

    Science.gov (United States)

    2014-01-01

    Background Concern has been raised that cervical collars may increase intracranial pressure in traumatic brain injury. The purpose of this study was to compare four types of cervical collars regarding efficacy of immobilizing the neck, effect on jugular venous pressure (JVP), as a surrogate for possible effect on intracranial pressure, and patient comfort in healthy volunteers. Methods The characteristics of four widely used cervical collars (Laerdal Stifneck® (SN), Vista® (VI), Miami J Advanced® (MJ), Philadelphia® (PH)) were studied in ten volunteers. Neck movement was measured with goniometry, JVP was measured directly through an endovascular catheter and participants graded the collars according to comfort on a scale 1–5. Results The mean age of participants was 27 ± 5 yr and BMI 26 ± 5. The mean neck movement (53 ± 9°) decreased significantly with all the collars (p  MJ > SN > PH). Conclusion Stifneck and Miami J collars offered the most efficient immobilization of the neck with the least effect on JVP. Vista and Miami J were the most comfortable ones. The methodology used in this study may offer a new approach to evaluate clinical efficacy and safety of neck collars and aid their continued development. PMID:24906207

  9. Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial

    OpenAIRE

    2006-01-01

    Objective To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. Design Pragmatic, open, multicentre, randomised controlled trial. Setting 11 hospitals in six NHS trusts. Participants 1972 people admitted to hospital as acute or elective patients. Interventions Participants were randomised to an alternating pressure mattress (n = 98...

  10. Pressure Drop

    Science.gov (United States)

    Lawson, Mike

    2010-01-01

    Mike Lawson briefly discussed pressure drop for aerospace applications and presented short stories about adventures experienced while working at NASA and General Dynamics, including exposure to technologies like the Crew and Equipment Translation Aid (CETA) cart and the SWME.

  11. Differential pressure gauge has fast response

    Science.gov (United States)

    Weber, H. S.

    1965-01-01

    Differential pressure gage with semiconductor type strain gage elements measures rapidly changing pressure. Output of the strain gage elements is a dc voltage that is directly proportional to the pressure difference being measured.

  12. High Blood Pressure: Unique to Older Adults

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z High Blood Pressure Hypertension Unique to Older Adults This section provides information ... Pressure Targets are Different for Very Old Adults High blood pressure (also called hypertension) increases your chance of having ...

  13. Experimental subarachnoid hemorrhage: subarachnoid blood volume, mortality rate, neuronal death, cerebral blood flow, and perfusion pressure in three different rat models.

    Science.gov (United States)

    Prunell, Giselle Fabiana; Mathiesen, Tiit; Diemer, Nils Henrik; Svendgaard, Niels-Aage

    2003-01-01

    To investigate which of three subarachnoid hemorrhage (SAH) models is the most suitable for studies of pathological and pathophysiological processes after SAH. SAH was induced in rats via intracranial endovascular perforation (perforation model), blood injection into the cisterna magna (300 microl), or blood injection into the prechiasmatic cistern (200 microl). The subarachnoid blood volume was quantitatively measured. Cerebral blood flow (CBF) (as assessed with laser Doppler flowmetry), intracranial pressure, and mean arterial blood pressure were recorded for 90 minutes after SAH. Mortality was recorded, and neuronal death was assessed in animals that survived 7 days after SAH. The subarachnoid blood volume was close to the injected amount after prechiasmatic SAH. In the other models, the volume varied between 40 and 480 microl. The mortality rates were 44% in the perforation SAH group, 25% in the prechiasmatic SAH group, and 0% in the cisterna magna SAH group; the corresponding values for neuronal death were 11, 44, and 28%. Cerebral perfusion pressure approached baseline values within 5 minutes after SAH in all three models. CBF decreased to approximately 35% of baseline values immediately after SAH in all groups; it gradually increased to normal values 15 minutes after SAH in the cisterna magna SAH group and to 60 and 89% of baseline values 90 minutes post-SAH in the perforation and prechiasmatic SAH groups. CBF was significantly correlated with the subarachnoid blood volume. The prechiasmatic SAH model seems to be the most suitable for study of the sequelae after SAH; it produces a significant decrease in CBF, an acceptable mortality rate, and substantial pathological lesions, with high reproducibility. The CBF reduction is predominantly dependent on the amount of subarachnoid blood.

  14. The impact of argon/oxygen low-pressure plasma on shear bond strength between a veneering composite and different PEEK materials.

    Science.gov (United States)

    Schwitalla, Andreas Dominik; Bötel, Friederike; Zimmermann, Tycho; Sütel, Mona; Müller, Wolf-Dieter

    2017-09-01

    The aim of the study was to evaluate the impact of low-pressure argon/oxygen plasma with and without previous sandblasting on the shear bond strength (SBS) between dental PEEK compounds and a veneering composite. Of one type of unfilled PEEK and two pigment powder filled PEEK compounds, forty rectangular plates each were prepared and polished up to 4000 grit. The samples were randomly assigned to four surface pre-treatment groups, each consisting of ten specimens (1. Untreated; 2. Plasma treatment; 3. Sandblasting; 4. Sandblasting+plasma treatment). Plasma treatment was performed for 35min using a low-pressure plasma system with a 1:1 mixture of the process gases argon and oxygen. Surface roughness and water contact angles were recorded. An adhesive (Visio.link, Bredent GmbH & Co KG, Senden, Germany) was applied onto the specimen surfaces and light cured. A mold was used to shape the veneering composite (Vita VM LC, Vita Zahnfabrik, Bad Säckingen, Germany) into a cylindrical form on the sample surface before light curing. SBS was measured after 24h incubation at 37°C in distilled water using a universal testing machine. The samples pre-treated according to group 4 (sandblasting and plasma treatment) showed the highest SBS overall, whereas the unfilled PEEK showed the highest SBS (19.8±2.46MPa) compared to the other PEEK materials (15.86±4.39MPa and 9.06±3.1MPa). Sandblasting and surface activation with low-pressure argon/oxygen plasma in combination with an adhesive causes a favorable increase in shear bond strength, especially on unfilled PEEK material. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Effect of Hydrogen Exposure on Mechanical and Tribological Behavior of CrxN Coatings Deposited at Different Pressures on IN718.

    Science.gov (United States)

    Obrosov, Aleksei; Sutygina, Alina N; Volinsky, Alex A; Manakhov, Anton; Weiß, Sabine; Kashkarov, Egor B

    2017-05-20

    In the current study, the properties of the Cr x N coatings deposited on the Inconel 718 superalloy using direct current reactive magnetron sputtering are investigated. The influence of working pressure on the microstructure, mechanical, and tribological properties of the Cr x N coatings before and after high-temperature hydrogen exposure is studied. The cross-sectional scanning electron micrographs indicate the columnar structure of the coatings, which changes from dense and compact columns to large columns with increasing working pressure. The Cr/N ratio increases from 1.4 to 1.9 with increasing working pressure from 300 to 900 mPa, respectively. X-ray diffraction analysis reveals a change from mixed hcp-Cr₂N and fcc-CrN structure to approximately stoichiometric Cr₂N phase. After gas-phase hydrogenation, the coating deposited at 300 mPa exhibits the lowest hydrogen absorption at 600 °C of all investigated coatings. The results indicate that the dense mixed cubic and hexagonal structure is preferential for hydrogen permeation resistance due to the presence of cubic phase with higher packing density in comparison to the hexagonal structure. After hydrogenation, no changes in phase composition were observed; however, a small amount of hydrogen is accumulated in the coatings. An increase of coating hardness and elastic modulus was observed after hydrogen exposure. Tribological tests reveal that hydrogenation leads to a decrease of the friction coefficient up to 20%-30%. The best value of 0.25 was reached for hydrogen exposed Cr x N coating deposited at 300 mPa.

  16. Chemical Stability of Ba0.5Sr0.5Co0.8Fe0.2O3-δ Under Different Oxygen Partial Pressure

    Science.gov (United States)

    Wang, Fang; Yashiro, Keiji; Amezawa, Koji; Mizusaki, Junichiro

    2013-07-01

    Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) is an outstanding material for cathode materials of solid oxide fuel cells (SOFCs). However the chemical stability of BSCF is still not well-understood. In this paper, in situ HT-XRD measurement was performed as a function of temperature and oxygen partial pressure, p(O2), to evaluate the chemical stability window of BSCF. The results inferred the phase transition of BSCF produced two kinds of impurity phases coexisted with BSCF at 800 °C in the relatively higher p(O2).

  17. Pressure Fluctuations on the Bed of Surge Tank at the H.P. Zimapan, Hgo., with Different Arrangements Studied on Hydraulic Model, with the Lowest Operation Conditions

    Directory of Open Access Journals (Sweden)

    H. Marengo–Mogollón

    2009-10-01

    Full Text Available In this paper, the pressure fluctuations of the surge tank in the Zimapan Hydroelectric Project are compared in a hydraulic model. The shaft is located lateral, over the conduction tunnel and in the simple form (permitting the tunnel entering the shaft, with and without orifice plates taking into account the demand and supply condition of energy with the minimum level of water of the conduction. It was determined the hydraulic efficiency and it was found that it was the best constructive option.

  18. Pressure relieving support surfaces (PRESSURE) trial: cost effectiveness analysis.

    Science.gov (United States)

    Iglesias, Cynthia; Nixon, Jane; Cranny, Gillian; Nelson, E Andrea; Hawkins, Kim; Phillips, Angela; Torgerson, David; Mason, Su; Cullum, Nicky

    2006-06-17

    To assess the cost effectiveness of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers in patients admitted to hospital. Cost effectiveness analysis carried out alongside the pressure relieving support surfaces (PRESSURE) trial; a multicentre UK based pragmatic randomised controlled trial. 11 hospitals in six UK NHS trusts. Intention to treat population comprising 1971 participants. Kaplan Meier estimates of restricted mean time to development of pressure ulcers and total costs for treatment in hospital. Alternating pressure mattresses were associated with lower overall costs (283.6 pounds sterling per patient on average, 95% confidence interval--377.59 pounds sterling to 976.79 pounds sterling) mainly due to reduced length of stay in hospital, and greater benefits (a delay in time to ulceration of 10.64 days on average,--24.40 to 3.09). The differences in health benefits and total costs for hospital stay between alternating pressure mattresses and alternating pressure overlays were not statistically significant; however, a cost effectiveness acceptability curve indicated that on average alternating pressure mattresses compared with alternating pressure overlays were associated with an 80% probability of being cost saving. Alternating pressure mattresses for the prevention of pressure ulcers are more likely to be cost effective and are more acceptable to patients than alternating pressure overlays.

  19. Wavelet neural network modeling in QSPR for prediction of solubility of 25 anthraquinone dyes at different temperatures and pressures in supercritical carbon dioxide.

    Science.gov (United States)

    Tabaraki, R; Khayamian, T; Ensafi, A A

    2006-09-01

    A wavelet neural network (WNN) model in quantitative structure property relationship (QSPR) was developed for predicting solubility of 25 anthraquinone dyes in supercritical carbon dioxide over a wide range of pressures (70-770 bar) and temperatures (291-423 K). A large number of descriptors were calculated with Dragon software and a subset of calculated descriptors was selected from 18 classes of Dragon descriptors with a stepwise multiple linear regression (MLR) as a feature selection technique. Six calculated and two experimental descriptors, pressure and temperature, were selected as the most feasible descriptors. The selected descriptors were used as input nodes in a wavelet neural network (WNN) model. The wavelet neural network architecture and its parameters were optimized simultaneously. The data was randomly divided to the training, prediction and validation sets. The predictive ability of the model was evaluated using validation data set. The root mean squares error (RMSE) and mean absolute errors were 0.339 and 0.221, respectively, for the validation data set. The performance of the WNN model was also compared with artificial neural network (ANN) model and the results showed the superiority of the WNN over ANN model.

  20. Undisturbed stance control in healthy adults is achieved differently along anteroposterior and mediolateral axes: evidence from visual feedback of various signals from center of pressure trajectories.

    Science.gov (United States)

    Rougier, Patrice R

    2009-05-01

    Provided through the screen of a monitor, the participant's resultant center of pressure (CPRes) movements from a force platform device, modified the postural performance of a healthy individual. However, these effects could largely vary with the axis that researchers consider (mediolateral [ML] or anteroposterior [AP]), because they know these controls are involved in 2 distinct ankle and hip mechanisms. To demonstrate this organization, the author tested a group of healthy adults in several conditions that gave the whole or some part of the information in the CPRes displacements. Compared with the CPRes feedback, left and right plantar CP or body weight distribution feedback deteriorated the control of the vertically projected center of gravity (CGv) along the ML and AP axes, whose amplitudes increased, respectively. These data highlight the primary role of loading or unloading and pressure variations in the achievement of postural control along each ML or AP axis, respectively. It is interesting that merging these 2 pieces of information (CPRes displacements) helped participants optimize their postural performance.

  1. The effect of different skin-ankle brace application pressures with and without shoes on single-limb balance, electromyographic activation onset and peroneal reaction time of lower limb muscles.

    Science.gov (United States)

    Papadopoulos, E S; Nikolopoulos, C S; Athanasopoulos, S

    2008-12-01

    Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures, with and without shoes, on quiet single-limb balance and the electromyographic (EMG) activation sequence of four lower limb muscles. Twelve male physical education students who volunteered to take part in the study were measured with and without shoes under three ankle brace conditions: (i) without brace, (ii) with brace and 30 kilopascals (kPa) application pressure and (iii) with brace and 60 kPa application pressure. Single-limb balance (anteroposterior and mediolateral parameter) was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris) activation onset. Peroneus longus reaction time was also measured by provoking a sudden subtalar inversion stress test using a trap-door. The results showed that the application of athletic footwear resulted in a significant difference between the condition with shoes and without shoes, with a significantly increased anteroposterior sway and sway velocity, in all three ankle brace application conditions with shoes (F=50.9, d.f.=1, plower limb muscles. Lastly, ankle brace application with 30 and 60 kPa application pressures, with and without athletic footwear, led to a significant delay in the peroneus longus reaction time (F=9.71, d.f.=2, plimb balance, and peroneal reaction time. The application of athletic footwear, further adversely affects these parameters significantly. Further research is needed in this area with more dynamic and functional measurements, before the safe use of ankle bracing can be widely recommended.

  2. Comparison of different calibration approaches for chloramphenicol quantification in chicken muscle by ultra-high pressure liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Pan, Xiao-Dong; Jiang, Wei; Wu, Ping-Gu

    2015-01-07

    Matrix-dependent signal suppression often occurs in quantitative analysis by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In this study, we investigated three calibration methods for compensation of signal suppression on chloramphenicol (CAP) quantification in chicken muscle. The data showed that the spiking recoveries by solvent standard calibration with a stable isotope labelled internal standard (SIL-IS) and matrix-matched standard calibration with a SIL-IS were significantly higher than by external matrix-matched standard calibration (P 0.05). The limit of detection (LOD) for external matrix matched standard calibration was 0.1 μg kg(-1), and that for SIL-IS calibration (including matrix matched and solvent dissolved standard) was 0.03 μg kg(-1).

  3. "allometry" Deterministic Approaches in Cell Size, Cell Number and Crude Fiber Content Related to the Physical Quality of Kangkong (Ipomoea reptans) Grown Under Different Plant Density Pressures

    Science.gov (United States)

    Selamat, A.; Atiman, S. A.; Puteh, A.; Abdullah, N. A. P.; Mohamed, M. T. M.; Zulkeefli, A. A.; Othman, S.

    Kangkong, especially the upland type (Ipomoea reptans) is popularly consumed as a vegetable dish in the South East Asian countries for its quality related to Vitamins (A and C) and crude fiber contents. Higher fiber contents would prevent from the occurrence of colon cancer and diverticular disease. With young stem edible portion, its cell number and size contribute to the stem crude fiber content. The mathematical approach of allometry of cell size, number, and fiber content of stem could be used in determining the 'best' plant density pressure in producing the quality young stem to be consumed. Basically, allometry is the ratio of relative increment (growth or change) rates of two parameters, or the change rate associated to the log of measured variables relationship. Kangkog grown equal or lower than 55 plants m-2 produced bigger individual plant and good quality (physical) kangkong leafy vegetable, but with lower total yield per unit area as compared to those grown at higher densities.

  4. Ethnic differences in inter- and intra-situational blood pressure variation: Comparisons among African-American, Hispanic-American, Asian-American, and European-American women.

    Science.gov (United States)

    James, Gary D; Bovbjerg, Dana H; Hill, Leah A

    2016-11-01

    The purpose of this study was to compare the daily inter- and intra-situational ambulatory blood pressure (BP) variation by ethnicity in women. The African-American (N = 82; Age = 39.7 + 8.9), Hispanic-American (N = 25; age = 37.5 + 9.4), Asian-American (N = 22; Age = 35.2 + 8.6), and European-American (N = 122; Age = 37.2+ 9.4) women in this study all worked in similar positions at two major medical centers in NYC. Each wore an ambulatory monitor during the course of one mid-week workday. Proportional BP changes from work or home to sleep, intra-situational BP variation (standard deviation [SD]) and mean situational BP levels were compared among the groups using ANOVA models. African-American and Asian-American women had significantly smaller proportional work-sleep systolic changes than either European- (P women, but the Asian-American women's changes tended to be smallest. The variability (SD) of diastolic BP at work was significantly greater among African- and Hispanic-American women compared to Asian- and European-American women (all P women had greater sleep variability than European-American women (P Asian-American women had the highest level of sleep diastolic pressure (all comparisons P Asian-American women have an attenuated proportional BP decline from waking environments to sleep compared to European-American and Hispanic-American women. Asian-American nocturnal BP may be elevated relative to all other groups. Am. J. Hum. Biol. 28:932-935, 2016. © 2016Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial.

    Science.gov (United States)

    Nixon, Jane; Cranny, Gillian; Iglesias, Cynthia; Nelson, E Andrea; Hawkins, Kim; Phillips, Angela; Torgerson, David; Mason, Su; Cullum, Nicky

    2006-06-17

    To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. Pragmatic, open, multicentre, randomised controlled trial. 11 hospitals in six NHS trusts. 1972 people admitted to hospital as acute or elective patients. Participants were randomised to an alternating pressure mattress (n = 982) or an alternating pressure overlay (n = 990). The proportion of participants developing a new pressure ulcer of grade 2 or worse; time to development of new pressure ulcers; proportions of participants developing a new ulcer within 30 days; healing of existing pressure ulcers; and patient acceptability. Intention to treat analysis found no difference in the proportions of participants developing a new pressure ulcer of grade 2 or worse (10.7% overlay patients, 10.3% mattress patients; difference 0.4%, 95% confidence interval--2.3% to 3.1%, P = 0.75). More overlay patients requested change owing to dissatisfaction (23.3%) than mattress patients (18.9%, P = 0.02). No difference was found between alternating pressure mattresses and alternating pressure overlays in the proportion of people who develop a pressure ulcer. ISRCTN 78646179.

  6. Village distance from urban centre as the prime modernization variable in differences in blood pressure and body mass index of adults of the Purari delta of the Gulf Province, Papua New Guinea.

    Science.gov (United States)

    Ulijaszek, Stanley J; Koziel, Slawomir; Hermanussen, Michael

    2005-01-01

    The study examined the extent to which the geographical proximity of villages to an urban centre and other modernization variables are associated with variation in blood pressure and body mass index (BMI) of adults of the Purari delta of the Gulf Province, Papua New Guinea (PNG). Mean BMI, systolic blood pressure (SBP) and diastolic blood pressure (DBP) of 292 adults surveyed in 1995-1997 in the Purari delta, PNG, are reported by village of residence, and related to modernization variables, including village of residence, urban life, urban connectedness, economic status and education. Mean BMI, SBP and DBP differ according to village of residence, there being a gradient in mean blood pressure from highest in the village closest to the urban centre, Baimuru, and lowest in the village most distant from it. The gradients in these variables across the three villages are not due to differences in age structures between the villages. Place of residence, which represents the distance from town, has the greatest impact on the BMI of males, while among the females, the number of relatives living in urban centres had a significant effect on BMI. For both males and females, place of residence has the strongest effect on SBP. While for the males, place of residence is the only significant factor associated with SBP, for the females, SBP is also associated with BMI, level of income and to a lesser extent with age. Very similar results were obtained for DBP. Distance to urban centre appears to have a strong effect, relative to other modernization variables, on BMI and blood pressure, this effect being far stronger for males than for females. In large part, this effect operates by way of differences in number of sources of income as well as number of close relatives of women who are resident in an urban centre. Reasons for the male-female differences observed may include gender differences in degree of mobility, and possibly greater physical sensitivity of males to the

  7. Dynamic calculations of a PWR - reactor building for different soil parameters for the safe shutdown earthquake and explosion pressure wave load cases

    International Nuclear Information System (INIS)

    Brandt, K.; Krutzik, N.; Kaiser, A.

    1982-01-01

    For different dynamic soil properties and soil dampings - ranging from very soft to very rigid soil parameters - time histoires of displacements and accelerations as well as response spectra are calculated for several floors for the reactor building of a nuclear power plant using a finite element shell model. As regards the loadcase safety earthquake the computations are carried out for four different soil properties, and the response spectra of different floors are compared. In the loadcase exterior explosion, results for three different soils are obtained. All results are discussed and explained extensively. (Author) [pt

  8. Pressure broadening of the electric dipole and Raman lines of CO2 by argon: Stringent test of the classical impact theory at different temperatures on a benchmark system

    International Nuclear Information System (INIS)

    Ivanov, Sergey V.; Buzykin, Oleg G.

    2016-01-01

    A classical approach is applied to calculate pressure broadening coefficients of CO 2 vibration–rotational spectral lines perturbed by Ar. Three types of spectra are examined: electric dipole (infrared) absorption; isotropic and anisotropic Raman Q branches. Simple and explicit formulae of the classical impact theory are used along with exact 3D Hamilton equations for CO 2 –Ar molecular motion. The calculations utilize vibrationally independent most accurate ab initio potential energy surface (PES) of Hutson et al. expanded in Legendre polynomial series up to l max = 24. New improved algorithm of classical rotational frequency selection is applied. The dependences of CO 2 half-widths on rotational quantum number J up to J=100 are computed for the temperatures between 77 and 765 K and compared with available experimental data as well as with the results of fully quantum dynamical calculations performed on the same PES. To make the picture complete, the predictions of two independent variants of the semi-classical Robert-Bonamy formalism for dipole absorption lines are included. This method. however, has demonstrated poor accuracy almost for all temperatures. On the contrary, classical broadening coefficients are in excellent agreement both with measurements and with quantum results at all temperatures. The classical impact theory in its present variant is capable to produce quickly and accurately the pressure broadening coefficients of spectral lines of linear molecules for any J value (including high Js) using full-dimensional ab initio - based PES in the cases where other computational methods are either extremely time consuming (like the quantum close coupling method) or give erroneous results (like semi-classical methods). - Highlights: • Classical and semi-classical Ar-broadening coefficients for CO 2 . • Infrared absorption and Raman isotropic and anisotropic lines of CO 2 . Low and high temperatures. • Application of very accurate potential energy

  9. [Negative pressure therapy: NPT].

    Science.gov (United States)

    Maillard, H

    2015-01-01

    Negative pressure therapy or treatment (NPT) is used very frequently in hospitals in both surgical and medical departments. NPT consists of maintaining the wound surface at a pressure below ambient atmospheric pressure by means of a specially designed dressing attached to a depressurisation device as well as a system to drain exudate. NPT has been shown to be beneficial in increasing blood flow, thanks to feedback resulting from the decreased oxygen pressure, angiogenesis and reduction of the wound surface area. The French Health Authority (HAS) has issued recommendations for good use in a specific and limited series of applications. NPT may be used in post-traumatic or post-surgical wounds, burns, and in chronic wounds, such as bedsores and ulcers. It is also effective as an adjuvant treatment for infected wounds. In recent years, various different NPT devices have become commercially available. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  10. Liquid chromatography coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry and post-column addition of metal salt solutions as a powerful tool for the metabolic profiling of Fusarium oxysporum.

    Science.gov (United States)

    Cirigliano, Adriana M; Rodriguez, M Alejandra; Gagliano, M Laura; Bertinetti, Brenda V; Godeas, Alicia M; Cabrera, Gabriela M

    2016-03-25

    Fusarium oxysporum L11 is a non-pathogenic soil-borne fungal strain that yielded an extract that showed antifungal activity against phytopathogens. In this study, reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry (API-QTOF-MS) was applied for the comprehensive profiling of the metabolites from the extract. The employed sources were electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). Post-column addition of metal solutions of Ca, Cu and Zn(II) was also tested using ESI. A total of 137 compounds were identified or tentatively identified by matching their accurate mass signals, suggested molecular formulae and MS/MS analysis with previously reported data. Some compounds were isolated and identified by NMR. The extract was rich in cyclic peptides like cyclosporins, diketopiperazines and sansalvamides, most of which were new, and are reported here for the first time. The use of post-column addition of metals resulted in a useful strategy for the discrimination of compound classes since specific adducts were observed for the different compound families. This technique also allowed the screening for compounds with metal binding properties. Thus, the applied methodology is a useful choice for the metabolic profiling of extracts and also for the selection of metabolites with potential biological activities related to interactions with metal ions. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. THE EFFECTS OF DIFFERENT TRUNK INCLINATIONS ON BILATERAL TRUNK MUSCULAR ACTIVITIES, CENTRE OF PRESSURE AND FORCE EXERTIONS IN STATIC PUSHING POSTURES.

    Science.gov (United States)

    Sanjaya, Kadek Heri; Lee, Soomin; Sriwarno, Andar Bagus; Shimomura, Yoshihito; Katsuura, Tetsuo

    2014-06-01

    In order to reconcile contradictory results from previous studies on manual pushing, a study was conducted to examine the effect of trunk inclination on muscular activities, centre of pressure (COP) and force exertion during static pushing. Ten subjects pushed at 0 degrees, 15 degrees, 30 degrees, and 45 degrees body inclinations in parallel and staggered feet stances. Wall and ground force plates measured pushing force, wall COP, vertical ground reaction force (GRF) and ground COP. Electromyogram data were recorded at 10 trunk muscle sites. Pushing force was found to increase with body inclination. GRF peaked at 15 degrees and reached its lowest level at the 45 degrees inclination. The lowest wall force plate standard deviation of COP displacement was found at the 30 degrees inclination. The lowest low back muscular activity was found at the 15 degrees and 30 degrees inclinations. Based on force exertion, muscular load, and stability, the 30 degrees body inclination was found to be the best posture for static pushing. This study also showed asymmetry in muscular activity and force exertion which has been received less attention in manual pushing studies. These findings will require further study.

  12. Experimental and artificial neural network based prediction of performance and emission characteristics of DI diesel engine using Calophyllum inophyllum methyl ester at different nozzle opening pressure

    Science.gov (United States)

    Vairamuthu, G.; Thangagiri, B.; Sundarapandian, S.

    2018-01-01

    The present work investigates the effect of varying Nozzle Opening Pressures (NOP) from 220 bar to 250 bar on performance, emissions and combustion characteristics of Calophyllum inophyllum Methyl Ester (CIME) in a constant speed, Direct Injection (DI) diesel engine using Artificial Neural Network (ANN) approach. An ANN model has been developed to predict a correlation between specific fuel consumption (SFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), Unburnt hydrocarbon (UBHC), CO, CO2, NOx and smoke density using load, blend (B0 and B100) and NOP as input data. A standard Back-Propagation Algorithm (BPA) for the engine is used in this model. A Multi Layer Perceptron network (MLP) is used for nonlinear mapping between the input and the output parameters. An ANN model can predict the performance of diesel engine and the exhaust emissions with correlation coefficient (R2) in the range of 0.98-1. Mean Relative Errors (MRE) values are in the range of 0.46-5.8%, while the Mean Square Errors (MSE) are found to be very low. It is evident that the ANN models are reliable tools for the prediction of DI diesel engine performance and emissions. The test results show that the optimum NOP is 250 bar with B100.

  13. High pressure effect on the color of minced cured restructured ham at different levels of drying, pH, and NaCl.

    Science.gov (United States)

    Bak, Kathrine Holmgaard; Lindahl, Gunilla; Karlsson, Anders H; Lloret, Elsa; Ferrini, Gabriele; Arnau, Jacint; Orlien, Vibeke

    2012-03-01

    Color changes of minced cured restructured ham was studied considering the effects of high pressure (HP) treatment (600MPa, 13°C, 5min), raw meat pH(24) (low, normal, high), salt content (15, 30g/kg), and drying (20%, 50% weight loss). Raw hams were selected based on pH(24) in Semimembranosus, mixed with additives, frozen, sliced, and dried using the Quick-Dry-Slice® process. Meat color (CIE 1976 L*a*b*) and reflectance spectra were measured before and after HP treatment. HP significantly increased L*, decreased a*, and decreased b* for restructured ham dried to 20% weight loss, regardless of salt content and pH(24). L* and a* were best preserved in high pH/high salt restructured ham. HP had no effect on the color of restructured ham dried to 50% weight loss. HP had no effect on the shape of reflectance curves, indicating that the pigment responsible for minced cured restructured ham color did not change due to HP. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Evaluation of browning ratio in an image analysis of apple slices at different stages of instant controlled pressure drop-assisted hot-air drying (AD-DIC).

    Science.gov (United States)

    Gao, Kun; Zhou, Linyan; Bi, Jinfeng; Yi, Jianyong; Wu, Xinye; Zhou, Mo; Wang, Xueyuan; Liu, Xuan

    2017-06-01

    Computer vision-based image analysis systems are widely used in food processing to evaluate quality changes. They are able to objectively measure the surface colour of various products since, providing some obvious advantages with their objectivity and quantitative capabilities. In this study, a computer vision-based image analysis system was used to investigate the colour changes of apple slices dried by instant controlled pressure drop-assisted hot air drying (AD-DIC). The CIE L* value and polyphenol oxidase activity in apple slices decreased during the entire drying process, whereas other colour indexes, including CIE a*, b*, ΔE and C* values, increased. The browning ratio calculated by image analysis increased during the drying process, and a sharp increment was observed for the DIC process. The change in 5-hydroxymethylfurfural (5-HMF) and fluorescent compounds (FIC) showed the same trend with browning ratio due to Maillard reaction. Moreover, the concentrations of 5-HMF and FIC both had a good quadratic correlation (R 2  > 0.998) with the browning ratio. Browning ratio was a reliable indicator of 5-HMF and FIC changes in apple slices during drying. The image analysis system could be used to monitor colour changes, 5-HMF and FIC in dehydrated apple slices during the AD-DIC process. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Biomassa e atividades microbianas em solo sob pastagem com diferentes lotações de ovinos Biomass and microbial activity in pasture soil under different sheep grazing pressure

    Directory of Open Access Journals (Sweden)

    Martha Regina Lucizano Garcia

    2007-04-01

    Full Text Available Os efeitos da lotação de animais na produção de ovinos têm sido bastante estudados. No entanto, informações sobre seus efeitos na biomassa e nas atividades microbianas e, em conseqüência, na fertilidade do solo de pastagens são escassas. Neste trabalho, os efeitos da lotação de ovinos (LO na biomassa e nas atividades microbianas responsáveis pela transformação dos compostos do C e N em solo de clima subtropical foram avaliados. As amostras de solo foram coletadas nas camadas de 0-10 e 10-20 cm de pastos com baixa LO (5 animais ha-1, alta LO (40-50 animais ha-1 e com ausência de animais, em um delineamento inteiramente casualizado em parcelas subdivididas, com seis repetições. Os maiores valores de biomassa microbiana e das atividades respiratória, nitrificante e enzimática (urease e protease foram encontrados nos solos dos pastos com baixa LO. Estes pastos também acumularam as maiores quantidades de matéria orgânica e N total. Essas variáveis foram reduzidas nos pastos sem animais ou com alta LO. Vegetação descontínua e intensa mineralização podem ter acarretado a diminuição dessas variáveis nos pastos com alta LO. Alta correlação foi obtida entre matéria orgânica, C orgânico e N total com as quantidades de biomassa microbiana e a atividade enzimática. A camada de 0-10 cm apresentou valores maiores das variáveis estudadas do que os encontrados na camada de 10-20 cm.The effect of grazing pressure in sheep production has been studied, but not in relation to soil microbiological parameters or the consequences on soil fertility. The effect of grazing pressure (GP by sheep on biomass and microbial activity related to C and N compounds cycling in subtropical region soil was studied. Soil samples were collected from the 0-10 cm and 10-20 cm layers in pastures with low GP (5 animals ha-1, high GP (40-50 animals ha-1 and in absence of animals, in a completely randomized design with 6 replicates. The highest values

  16. Race and sex differences in cardiovascular α-adrenergic and β-adrenergic receptor responsiveness in men and women with high blood pressure.

    Science.gov (United States)

    Sherwood, Andrew; Hill, LaBarron K; Blumenthal, James A; Johnson, Kristy S; Hinderliter, Alan L

    2017-05-01

    Hypertension is associated with unfavorable changes in adrenergic receptor responsiveness, but the relationship of race and sex to adrenergic receptor responsiveness in the development of cardiovascular disease is unclear. This study examined α-adrenergic and ß-adrenergic receptor responsiveness in African-American and white men and women with untreated high blood pressure (BP) (HBP) and with normal BP. The study sample comprised 161 African-American and white men and women in the age range 25-45 years. Isoproterenol, a nonselective ß-adrenergic receptor agonist, was administered intravenously to determine the bolus dose required to increase heart rate by 25 bpm, an index of β-adrenergic receptor responsiveness. Similarly, phenylephrine, an α1-adrenergic receptor agonist, was administered to determine the bolus dose required to increase BP by 25 mmHg, an index of vascular α1-adrenergic receptor responsiveness. HBP (P < 0.01), male sex (P = 0.04), and higher BMI (P < 0.01) were all associated with reduced β-adrenergic receptor responsiveness, with a similar trend observed for African-American race (P = 0.07). Conversely, α1-adrenergic receptor responsiveness was increased in association with HBP (P < 0.01), female sex (P < 0.01), and African-American race (P < 0.01). In the early stages of hypertension, cardiovascular β-adrenergic receptors demonstrate blunted responsiveness, whereas conversely α1-adrenergic receptors exhibit increased responsiveness. This pattern of receptor changes is especially evident in men and African-Americans, is exacerbated by obesity, and may contribute to the development of cardiovascular disease.

  17. High-pressure microfluidics

    Science.gov (United States)

    Hjort, K.

    2015-03-01

    When using appropriate materials and microfabrication techniques, with the small dimensions the mechanical stability of microstructured devices allows for processes at high pressures without loss in safety. The largest area of applications has been demonstrated in green chemistry and bioprocesses, where extraction, synthesis and analyses often excel at high densities and high temperatures. This is accessible through high pressures. Capillary chemistry has been used since long but, just like in low-pressure applications, there are several potential advantages in using microfluidic platforms, e.g., planar isothermal set-ups, large local variations in geometries, dense form factors, small dead volumes and precisely positioned microstructures for control of reactions, catalysis, mixing and separation. Other potential applications are in, e.g., microhydraulics, exploration, gas driven vehicles, and high-pressure science. From a review of the state-of-art and frontiers of high pressure microfluidics, the focus will be on different solutions demonstrated for microfluidic handling at high pressures and challenges that remain.

  18. Blood Pressure Test

    Science.gov (United States)

    ... pressure monitors may have some limitations. Tracking your blood pressure readings It can be helpful in diagnosing or ... more Stage 2 high blood pressure (hypertension) Elevated blood pressure and stages 1 and 2 high blood pressure ( ...

  19. Evidence of uneven selective pressure on different subsets of the conserved human genome; implications for the significance of intronic and intergenic DNA

    Directory of Open Access Journals (Sweden)

    MacKenzie Alasdair

    2009-12-01

    Full Text Available Abstract Background Human genetic variation produces the wide range of phenotypic differences that make us individual. However, little is known about the distribution of variation in the most conserved functional regions of the human genome. We examined whether different subsets of the conserved human genome have been subjected to similar levels of selective constraint within the human population. We used set theory and high performance computing to carry out an analysis of the density of Single Nucleotide Polymorphisms (SNPs within the evolutionary conserved human genome, at three different selective stringencies, intersected with exonic, intronic and intergenic coordinates. Results We demonstrate that SNP density across the genome is significantly reduced in conserved human sequences. Unexpectedly, we further demonstrate that, despite being conserved to the same degree, SNP density differs significantly between conserved subsets. Thus, both the conserved exonic and intronic genomes contain a significantly reduced density of SNPs compared to the conserved intergenic component. Furthermore the intronic and exonic subsets contain almost identical densities of SNPs indicating that they have been constrained to the same degree. Conclusion Our findings suggest the presence of a selective linkage between the exonic and intronic subsets and ascribes increased significance to the role of introns in human health. In addition, the identification of increased plasticity within the conserved intergenic subset suggests an important role for this subset in the adaptation and diversification of the human population.

  20. Time to achieve target mean arterial pressure during resuscitation from experimental anaphylactic shock in an animal model. A comparison of adrenaline alone or in combination with different volume expanders.

    Science.gov (United States)

    Tajima, K; Zheng, F; Collange, O; Barthel, G; Thornton, S N; Longrois, D; Levy, B; Audibert, G; Malinovsky, J M; Mertes, P M

    2013-11-01

    Anaphylactic shock is a rare, but potentially lethal complication, combining life-threatening circulatory failure and massive fluid shifts. Treatment guidelines rely on adrenaline and volume expansion by intravenous fluids, but there is no solid evidence for the choice of one specific type of fluid over another. Our purpose was to compare the time to achieve target mean arterial pressure upon resuscitation using adrenaline alone versus adrenaline with different resuscitation fluids in an animal model and to compare the tissue oxygen pressures (PtiO2) with the various strategies. Twenty-five ovalbumin-sensitised Brown Norway rats were allocated to five groups after anaphylactic shock induction: vehicle (CON), adrenaline alone (AD), or adrenaline with isotonic saline (AD+IS), hydroxyethyl starch (AD+HES) or hypertonic saline (AD+HS). Time to reach a target mean arterial pressure value of 75 mmHg, cardiac output, skeletal muscle PtiO2, lactate/pyruvate ratio and cumulative doses of adrenaline were recorded. Non-treated rats died within 15 minutes. The target mean arterial pressure value was reached faster with AD+HES (median: 10 minutes, range: 7.5 to 12.5 minutes) and AD+IS (median: 17.5 minutes, range: 5 to 25 minutes) versus adrenaline alone (median: 25 minutes, range: 20-30 minutes). There were also reduced adrenaline requirements in these groups. The skeletal muscle PtiO2 was restored only in the AD+HES group. Although direct extrapolation to humans should be made with caution, our results support the combined use of adrenaline and volume expansion for resuscitation from anaphylactic shock. When used with adrenaline the most effective fluid was hydroxyethyl starch, whereas hypertonic saline was the least effective.

  1. Whole-plant growth and N utilization in transgenic rice plants with increased or decreased Rubisco content under different CO2 partial pressures.

    Science.gov (United States)

    Sudo, Emi; Suzuki, Yuji; Makino, Amane

    2014-11-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) strongly limits photosynthesis at lower CO2 concentration [CO2] whereas [corrected] Rubisco limitation is cancelled by elevated [CO2]. Therefore, increase or reduction in Rubisco content by transformation with a sense or an antisense RBCS construct are expected to alter the biomass production under different CO2 levels. RBCS-sense (125% Rubisco of wild-type) and -antisense (35% Rubisco of wild-type) rice (Oryza sativa L.) plants were grown for 63 days at three different CO2 levels: low [CO2] (28 Pa), normal [CO2] (40 Pa) and elevated [CO2] (120 Pa). The biomass of RBCS-sense plants was 32% and 15% greater at low [CO2] and normal [CO2] than that of the wild-type plants, respectively, but did not differ at elevated [CO2]. Conversely, the biomass of RBCS-antisense plants was the smallest at low [CO2]. Thus, overproduction of Rubisco was effective for biomass production at low [CO2]. Greater biomass production at low [CO2] in RBCS-sense plants was caused by an increase in the net assimilation rate, and associated with an increase in the amount of N uptake. Furthermore, Rubisco overproduction in RBCS-sense plants was also promoted at low [CO2]. Although it seems that low [CO2]-growth additionally stimulates the effect of RBCS overexpression, such a phenomenon observed at low [CO2] was mediated through an increase in total leaf N content. Thus, the dependence of the growth improvement in RBCS-sense rice on growth [CO2] was closely related to the degree of Rubisco overproduction which was accompanied not only by leaf N content but also by whole plant N content. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. The Facioscapulohumeral muscular dystrophy region on 4qter and the homologous locus on 10qter evolved independently under different evolutionary pressure

    Directory of Open Access Journals (Sweden)

    Frusciante Roberto

    2007-03-01

    Full Text Available Abstract Background The homologous 4q and 10q subtelomeric regions include two distinctive polymorphic arrays of 3.3 kb repeats, named D4Z4. An additional BlnI restriction site on the 10q-type sequence allows to distinguish the chromosomal origin of the repeats. Reduction in the number of D4Z4 repeats below a threshold of 10 at the 4q locus is tightly linked to Facioscapulohumeral Muscular Dystrophy (FSHD, while similar contractions at 10q locus, are not pathogenic. Sequence variations due to the presence of BlnI-sensitive repeats (10q-type on chromosome 4 or viceversa of BlnI-resistant repeats (4q-type on chromosome 10 are observed in both alleles. Results We analysed DNA samples from 116 healthy subiects and 114 FSHD patients and determined the size distributions of polymorphic 4q and 10q alleles, the frequency and the D4Z4 repeat assortment of variant alleles, and finally the telomeric sequences both in standard and variant alleles. We observed the same frequency and types of variant alleles in FSHD patients and controls, but we found marked differences between the repeat arrays of the 4q and 10q chromosomes. In particular we detected 10q alleles completely replaced by the 4q subtelomeric region, consisting in the whole set of 4q-type repeats and the distal telomeric markers. However the reciprocal event, 10q-type subtelomeric region on chromosome 4, was never observed. At 4q locus we always identified hybrid alleles containing a mixture of 4q and 10q-type repeats. Conclusion The different size distribution and different structure of 10q variant alleles as compared with 4q suggests that these loci evolved in a different manner, since the 4q locus is linked to FSHD, while no inheritable disease is associated with mutations in 10qter genomic region. Hybrid alleles on chromosome 4 always retain a minimum number of 4q type repeats, as they are probably essential for maintaining the structural and functional properties of this subtelomeric region

  3. Pressure Ulcer Prevention

    Science.gov (United States)

    2009-01-01

    . Summary of Findings Risk Assessment There is very low quality evidence to support the hypothesis that allocating the type of pressure-relieving equipment according to the person’s level of pressure ulcer risk statistically decreases the incidence of pressure ulcer development. Similarly, there is very low quality evidence to support the hypothesis that incorporating a risk assessment into nursing practice increases the number of preventative measures used per person and that these interventions are initiated earlier in the care continuum. Pressure Redistribution Devices There is moderate quality evidence that the use of an alternative foam mattress produces a relative risk reduction (RRR) of 69% in the incidence of pressure ulcers compared with a standard hospital mattress. The evidence does not support the superiority of one particular type of alternative foam mattress. There is very low quality evidence that the use of an alternating pressure mattress is associated with an RRR of 71% in the incidence of grade 1 or 2 pressure ulcers. Similarly, there is low quality evidence that the use of an alternating pressure mattress is associated with an RRR of 68% in the incidence of deteriorating skin changes. There is moderate quality evidence that there is a statistically nonsignificant difference in the incidence of grade 2 pressure ulcers between persons using an alternating pressure mattress and those using an alternating pressure overlay. There is moderate quality evidence that the use of an Australian sheepskin produces an RRR of 58% in the incidence of pressure ulcers grade 1 or greater. There is also evidence that sheepskins are uncomfortable to use. The Pressure Ulcer Advisory Panel noted that, in general, sheepskins are not a useful preventive intervention because they bunch up in a patient’s bed and may contribute to wound infection if not properly cleaned, and this reduces their acceptability as a preventive intervention. There is very low quality evidence that

  4. Ten years of marketing approvals of anticancer drugs in Europe: regulatory policy and guidance documents need to find a balance between different pressures.

    Science.gov (United States)

    Apolone, G; Joppi, R; Bertele', V; Garattini, S

    2005-09-05

    Despite important progress in understanding the molecular factors underlying the development of cancer and the improvement in response rates with new drugs, long-term survival is still disappointing for most common solid tumours. This might be because very little of the modest gain for patients is the result of the new compounds discovered and marketed recently. An assessment of the regulatory agencies' performance may suggest improvements. The present analysis summarizes and evaluates the type of studies and end points used by the EMEA to approve new anticancer drugs, and discusses the application of current regulations. This report is based on the information available on the EMEA web site. We identified current regulatory requirements for anticancer drugs promulgated by the agency and retrieved them in the relevant directory; information about empirical evidence supporting the approval of drugs for solid cancers through the centralised procedure were retrieved from the European Public Assessment Report (EPAR). We surveyed documents for drug applications and later extensions from January 1995, when EMEA was set up, to December 2004. We identified 14 anticancer drugs for 27 different indications (14 new applications and 13 extensions). Overall, 48 clinical studies were used as the basis for approval; randomised comparative (clinical) trial (RCT) and Response Rate were the study design and end points most frequently adopted (respectively, 25 out of 48 and 30 out of 48). In 13 cases, the EPAR explicitly reported differences between arms in terms of survival: the range was 0-3.7 months, and the mean and median differences were 1.5 and 1.2 months. The majority of studies (13 out of 27, 48%) involved the evaluation of complete and/or partial tumour responses, with regard to the end points supporting the 27 indications. Despite the recommendations of the current EMEA guidance documents, new anticancer agents are still often approved on the basis of small single arm

  5. High pressure phase transformations revisited

    Science.gov (United States)

    Levitas, Valery I.

    2018-04-01

    High pressure phase transformations play an important role in the search for new materials and material synthesis, as well as in geophysics. However, they are poorly characterized, and phase transformation pressure and pressure hysteresis vary drastically in experiments of different researchers, with different pressure transmitting media, and with different material suppliers. Here we review the current state, challenges in studying phase transformations under high pressure, and the possible ways in overcoming the challenges. This field is critically compared with fields of phase transformations under normal pressure in steels and shape memory alloys, as well as plastic deformation of materials. The main reason for the above mentioned discrepancy is the lack of understanding that there is a fundamental difference between pressure-induced transformations under hydrostatic conditions, stress-induced transformations under nonhydrostatic conditions below yield, and strain-induced transformations during plastic flow. Each of these types of transformations has different mechanisms and requires a completely different thermodynamic and kinetic description and experimental characterization. In comparison with other fields the following challenges are indicated for high pressure phase transformation: (a) initial and evolving microstructure is not included in characterization of transformations; (b) continuum theory is poorly developed; (c) heterogeneous stress and strain fields in experiments are not determined, which leads to confusing material transformational properties with a system behavior. Some ways to advance the field of high pressure phase transformations are suggested. The key points are: (a) to take into account plastic deformations and microstructure evolution during transformations; (b) to formulate phase transformation criteria and kinetic equations in terms of stress and plastic strain tensors (instead of pressure alone); (c) to develop multiscale continuum

  6. Modified headspace solid-phase microextraction for the determination of quantitative relationships between components of mixtures consisting of alcohols, esters, and ethers - impact of the vapor pressure difference of the compounds.

    Science.gov (United States)

    Dawidowicz, Andrzej Lech; Szewczyk, Joanna; Dybowski, Michal P

    2017-07-01

    The quantitative relationship between analytes established by the headspace solid-phase microextraction procedure for multicomponent mixtures depends not only on the character and strength of interactions of individual components with solid-phase microextraction fiber but also on their vapor pressure in the applied headspace solid-phase microextraction system. This study proves that vapor pressure is of minor importance when the sample is dissolved/suspended in a low-volatility liquid of the same physicochemical character as that of the used solid phase microextraction fiber coating. It is demonstrated for mixtures of alcohols, esters, ethers and their selected representatives by applying a headspace solid-phase microextraction system composed of Carbowax fiber and sample solutions in polyethyleneglycol. The observed differences in quantitative relations between components of the examined mixtures established by their direct analysis and by modified headspace solid-phase microextraction are insignificant (F exp  difference between individual components of the examined mixture in the applied headspace solid phase microextraction system due to low components concentration in polyethyleneglycol suspensions (Raoult's law) and due to strong specific interactions of analyte molecules with polyethyleneglycol molecules. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Dissemination of bacteria labeled with technetium-99m after laparotomy and abdominal insufflation with different CO2 pressures on rats; Disseminacao de bacterias marcadas com tecnecio-99m apos laparotomia e insuflacao com diferentes pressoes de CO2 em ratos

    Energy Technology Data Exchange (ETDEWEB)

    Pitombo, Marcos Bettini; Faria, Clarice Abreu dos Santos Albuquerque de; Steinbruck, Klaus [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Escola de Medicina]. E-mail: mpitombo@urbi.com.br; Bernardo, Luciana Camargo; Bernardo Filho, Mario[Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes (IBRAG). Lab. de Radiofarmacia Experimental

    2008-01-15

    Purpose: To asses the dissemination of bacteria labeled with technetium-99m (99mTc) from peritoneal cavity after different surgical procedures. Methods: Bacteria of the Escherichia coli species labeled with 99mTc were used in a concentration of 108 units of colony-makers for ml (UFC/ml) and 1 ml was inoculated through intra-peritoneal via. Forty-eight rats were divided into four groups: control, laparotomy, pneumoperitoneum with 10 mmHg and pneumoperitoneum with 20 mmHg of CO2. Procedures were performed 20 min after injection of the inoculum and lasted 30 min. Animals were sacrificed after six hours (Group 1) and 24 hours (Group 2). Samples of blood, liver and spleen were collected for radioactivity counting. Results: After six hours, indirect detection of the bacteria in different organs was uniform in all groups. After 24 hours, a larger detection of technetium was observed in the livers of animals of the group insufflated with 20 mmHg of CO2, when compared with those of control group (p<0.01). The other groups did not present statistically significant variations. Conclusions: The use of a higher intra-abdominal pressure was associated with a higher bacterial dissemination to the liver. The application of lower intra-abdominal pressures may be associated with a lower dissemination of the infectious status during laparoscopic approach of peritonitis status. (author)

  8. Peri-implant bone formation of non-thermal atmospheric pressure plasma-treated zirconia implants with different surface roughness in rabbit tibiae.

    Science.gov (United States)

    Shon, Won-Jun; Chung, Shin Hye; Kim, Hong-Kyun; Han, Geum-Jun; Cho, Byeong-Hoon; Park, Young-Seok

    2014-05-01

    The aim of this study was to evaluate and compare the osseointegration of powder-injection molded (PIM) zirconia implants in rabbit tibiae with or without He plasma treatment. Twenty-five rabbits received 4 types of external hex implants with identical geometry in the tibiae: PIM zirconia implants, roughened PIM zirconia implants, plasma-treated PIM zirconia implants, and plasma-treated roughened PIM zirconia implants. The contact angles of the four types of implants were evaluated. Removal torque tests and histomorphometric analyses were performed. The plasma treatment markedly enhanced the hydrophilicity, but did not seem to change the surface topography of the PIM zirconia implants. There were statistically significant differences in the bone-to-implant contact (BIC) ratios, bone volume (BV/TV), and removal torque values (RTQ) among the tested implant types (P zirconia implants made the surface more hydrophilic and enhanced the osseointegration of the implants without changing the micro-topography. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  9. Estimation of vapour pressure and partial pressure of subliming ...

    Indian Academy of Sciences (India)

    Administrator

    temperature curves are calculated at 80, 160 and 1000 mbar for salicylic acid and vanadyl bis-2,4- pentanedionate, a precursor used for chemical vapour deposition of vanadium oxides. Using a modification of the Langmuir equation, the partial pressure of these materials at different total pressures is also determined.

  10. Estimation of vapour pressure and partial pressure of subliming ...

    Indian Academy of Sciences (India)

    Administrator

    substance due to the flowing gas in the thermogravimetric analysis (TGA) apparatus was taken into account. ... the partial pressure, V the volume, n number of moles (of the vapour), R the universal gas constant and T the .... Figure 7. Molar concentration of vanadium metal as a func- tion of temperature at different pressures.

  11. Lying Posture Classification for Pressure Ulcer Prevention

    Directory of Open Access Journals (Sweden)

    Aung Phyo Wai

    2010-01-01

    Full Text Available Pressure ulcers are a common problem among patients with limited mobility, such as those bed-bound and wheelchair-bound. Constant and prolonged applied pressure is one of the extrinsic factors contributing to the development of pressure ulcers. Analyzing lying postures together with interface pressure measurements from a pressure sensitive bed helps revealing pressure hot spots that can potentially lead to pressure ulcer development. We propose an intelligent system that features lying posture classification with pressure hot spots identification based on interface pressure measurements to possibly identify potential pressure ulcer risk and to provide effective preventive measures. Experimental outcomes correctly classify different lying postures with an accuracy of up to 93%. The proposed system is expected to assist caregivers to detect risk evidence and to provide timely and appropriate interventions for effective pressure ulcer prevention.

  12. Hypertensive response to raised intracranial pressure in infancy.

    OpenAIRE

    Kaiser, A M; Whitelaw, A G

    1988-01-01

    Mean arterial pressure and intracranial pressure were measured serially in six infants with intracranial hypertension (intracranial pressure greater than 20 mm Hg), and cerebral perfusion pressure was calculated from their difference. Overall, mean arterial pressure increased with rising intracranial pressure at a mean rate of 0.20 mm Hg/mm Hg. This caused a fall in cerebral perfusion pressure with increasing intracranial pressure at a mean rate of 0.80 mm Hg/mm Hg overall, although cerebral ...

  13. Temporal shifts in floristic and avian diversity in Mediterranean pine forest ecosystems under different fire pressure: The island of Zakynthos as a case study

    Directory of Open Access Journals (Sweden)

    Konstantinos Poirazidis

    2014-01-01

    Full Text Available We evaluated how fire impacts the ecological coherence of Aleppo pine forests and their biodiversity over a 40-year period. The study area forms part of an insular ecosystem of Zakynthos Island (Zante in western Greece, which forms part of the Ionian Islands. Post-fire effects were studied for both plant and bird diversity at 20 sampling plots, using stratified random sampling, during the summer of 2012. The plots were selected based on the frequency of burning since the 1970s. Sites were categorized as: 1 no burning for >40 years, 2 burnt once in the 1970s, 3 burnt twice, first in the 1970s and again in 2000–2010, 4 burnt three times, first in the 1970s, and twice more in 2000–2010, and 5 burnt four times, first in the1970s, twice more in 2000–2010, and again in 2011. A total of 79 plant species and 26 bird species were recorded at the studied sites. One-way ANOVA analysis showed that fire intensity has a significant impact on alpha floristic diversity. Average plant species richness at sites that burned in 2011 was significantly higher than in those that burned in the 1970s. Detected differences in bird species richness were not significant; however, more species were documented in the forested habitats (unburnt for >40 years, and burnt in the 1970s. The highest Jaccard similarity index was observed between the sites that had not burned for more than 40 years and the sites that burned in the 1970s. The lowest floristic similarity to non-burnt sites was observed between the recently burnt sites in 2011 and the sites that burned in the 1970s. The lowest bird similarity was detected between recently burnt sites in 2011 and sites that had not burned for more than 40 years. DCA ordination showed the presence of a clear fire gradient, from intensively burnt open sites to non-burnt forest sites. We suggest that fire is essential to maintain biodiversity in Aleppo pine forests, but only at intermediate frequency.

  14. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

  15. Normal Pressure Hydrocephalus (NPH)

    Science.gov (United States)

    ... local chapter Join our online community Normal Pressure Hydrocephalus (NPH) Normal pressure hydrocephalus is a brain disorder ... Symptoms Diagnosis Causes & risks Treatments About Normal Pressure Hydrocephalus Normal pressure hydrocephalus occurs when excess cerebrospinal fluid ...

  16. Comparison of ambulatory blood pressure-lowering effects of higher doses of different calcium antagonists in uncontrolled hypertension: the Calcium Antagonist Controlled-Release High-Dose Therapy in Uncontrolled Refractory Hypertensive Patients (CARILLON) Study.

    Science.gov (United States)

    Mizuno, Hiroyuki; Hoshide, Satoshi; Tomitani, Naoko; Kario, Kazuomi

    2017-10-01

    Data are sparse regarding ambulatory blood pressure (BP) reduction of up-titration from a standard dose to a high dose in both nifedipine controlled-release (CR) and amlodipine. This was a prospective, randomized, multicenter, open-label trial. Fifty-one uncontrolled hypertensives medicated by two or more antihypertensive drugs including a renin-angiotensin system inhibitor and a calcium antagonist were randomly assigned to either the nifedipine CR (80 mg)/candesartan (8 mg) group or the amlodipine (10 mg)/candesartan (8 mg) group. The changes in 24-hr BP were comparable between the groups. The nifedipine group demonstrated a significant decrease in their urinary albumin creatinine ratio, whereas the amlodipine group demonstrated a significant decrease in their NTproBNP level. However, there was no significant difference in any biomarkers between the two groups. Nifedipine showed an almost equal effect on ambulatory blood pressure as amlodipine. Their potentially differential effects on renal protection and NTproBNP should be tested in larger samples.

  17. Novel pulsatile cerebrospinal fluid model to assess pressure manometry and fluid sampling through spinal needles of different gauge: support for the use of a 22 G spinal needle with a tapered 27 G pencil-point tip.

    Science.gov (United States)

    Ginosar, Y; Smith, Y; Ben-Hur, T; Lovett, J M; Clements, T; Ginosar, Y D; Davidson, E M

    2012-02-01

    Parallel-walled spinal needles ≤ 22 G are routinely used for lumbar puncture, despite a reported ≥ 32% incidence of post-dural puncture headache. A tapered spinal needle (22 G shaft, 27 G tip) is in use in our institution. We hypothesized that despite the smaller dural puncture hole, this needle has similar cerebrospinal fluid (CSF) pressure equilibration times and CSF sampling times to a standard 22 G needle and assessed a range of spinal needles using an experimental pulsatile CSF reservoir. The pulsatile CSF reservoir had an oscillating pressure varying between 25 and 15 cm H(2)O at a cycle frequency of 80 s(-1). We tested seven parallel-walled spinal needles (18-27 G) and the tapered 22/27 G needle. CSF pressure was measured every 2 s by manometry. The time to collect 1 ml CSF samples was measured. Saline 0.9% and mannitol 20% were tested separately. One-way ANOVA with Bonferroni post-hoc test was used to compare 22G, 27G and 22/27G needles. The mean [standard deviation (sd)] CSF pressure equilibration time (saline) was 40.7 (6.4), 108.7 (6.1), and 51.3 (4.6) s for the 22, 27, and 22/27 G needles (P< 0.0001 for comparisons between 27 G and other needles). The mean (sd) CSF sampling time (saline) was 40.3 (3.1), 225.3 (10.0), and 63.0 (5.2) s for the 22, 27, and 22/27 G needles (P< 0.0001 for comparisons between 27 G and other needles, and P= 0.019 between 22 and 22/27 G needles). Saline was different from mannitol for both measurements and all needles (P< 0.0001). A 22/27 G tapered spinal needle has similar flow properties to the 22 G needle, despite a 27 G tip.

  18. Pressure effects on nanostructured manganites

    International Nuclear Information System (INIS)

    Acha, C.; Garbarino, G.; Leyva, A.G.

    2007-01-01

    We have measured the pressure sensitivity of magnetic properties on La 5/8-y Pr y Ca 3/8 MnO 3 (y=0.3) nanostructured powders. Samples were synthesized following a microwave assisted denitration process and a final heat treatment at different temperatures to control the grain size of the samples. A span in grain diameters from 40 nm to ∼1000 nm was obtained. Magnetization curves as a function of temperature were measured following different thermomagnetic histories. AC susceptibility as a function of temperature was also measured at different hydrostatic pressures (up to 10 kbar) and for different frequencies. Our results indicate that the nanostructuration plays a role of an internal pressure, producing a structural deformation with similar effects to those obtained under an external hydrostatic pressure

  19. The effect of positive end-expiratory pressure on pulse pressure ...

    African Journals Online (AJOL)

    The effect of positive end-expiratory pressure on pulse pressure variation. FJ Smith, M Geyser, I Schreuder, PJ Becker. Abstract. Objectives: To determine the effect of different levels of positive end-expiratory pressure (PEEP) on pulse pressure variation (PPV). Design: An observational study. Setting: Operating theatres of a ...

  20. Roller pressure algometry as a new tool for assessing dynamic pressure sensitivity in migraine

    DEFF Research Database (Denmark)

    Guerrero-Peral, Ángel L.; Ruíz, Marina; Barón, Johanna

    2018-01-01

    Objectives To explore the validity of the roller pressure algometer as a new tool for evaluating dynamic pressure sensitivity by assessing its association with pain features and widespread pressure pain sensitivity in migraine women, and also to determine whether dynamic pressure algometry differ...

  1. The physics of osmotic pressure

    Science.gov (United States)

    Bowler, M. G.

    2017-09-01

    Osmosis drives the development of a pressure difference of many atmospheres between a dilute solution and pure solvent with which it is in contact through a semi-permeable membrane. The educational importance of this paper is that it presents a novel treatment in terms of fluid mechanics that is quantitative and exact. It is also simple and intuitive, showing vividly how osmotic pressures are generated and maintained in equilibrium, driven by differential solvent pressures. The present rigorous analysis using the virial theorem seems unknown and can be easily understood—and taught—at various different levels. It should be valuable to undergraduates, graduate students and indeed to the general physicist.

  2. Peer Pressure

    Science.gov (United States)

    ... you when they think you're making a mistake or doing something risky. Socializing. Your peer group gives you opportunities to try out new social skills. Getting to know lots of different people — such as classmates or teammates — gives you a chance to learn how to expand your circle of friends, build ...

  3. Análise da pressão plantar e do equilíbrio postural em diferentes fases da gestação Analysis of plantar pressure and postural balance during different phases of pregnancy

    Directory of Open Access Journals (Sweden)

    SI Ribas

    2007-10-01

    hindfoot (HFP; distance between the medial borders of the foot (width of support base; the distance from the center of force to the anterior (COF-A and posterior (COF-P limits of the foot; anteroposterior (AP and mediolateral (ML COF displacements; and the contact area (CA. RESULTS: There were no differences in peak contact pressures and COF-A and COF-P distances between the groups. The AP displacement was greater (p 0.05 between the groups regarding ML displacement. There was a positive correlation between weight gained during pregnancy and CA for the 2T group, and between weight gain and WFP in the right feet in the 1T group. CONCLUSION: The results demonstrate the influence of the anatomical and physiological changes inherent to pregnancy on plantar pressure. They also suggest that postural equilibrium decreases in the third trimester, associated with greater AP displacement during this phase.

  4. Solvation pressure as real pressure: I. Ethanol and starch under negative pressure

    CERN Document Server

    Uden, N W A V; Faux, D A; Tanczos, A C; Howlin, B; Dunstan, D J

    2003-01-01

    The reality of the solvation pressure generated by the cohesive energy density of liquids is demonstrated by three methods. Firstly, the Raman spectrum of ethanol as a function of cohesive energy density (solvation pressure) in ethanol-water and ethanol-chloroform mixtures is compared with the Raman spectrum of pure ethanol under external hydrostatic pressure and the solvation pressure and hydrostatic pressure are found to be equivalent for some transitions. Secondly, the bond lengths of ethanol are calculated by molecular dynamics modelling for liquid ethanol under pressure and for ethanol vapour. The difference in bond lengths between vapour and liquid are found to be equivalent to the solvation pressure for the C-H sub 3 , C-H sub 2 and O-H bond lengths, with discrepancies for the C-C and C-O bond lengths. Thirdly, the pressure-induced gelation of potato starch is measured in pure water and in mixtures of water and ethanol. The phase transition pressure varies in accordance with the change in solvation pre...

  5. Reproducibility of calibration results by 0-A-0 pressurization procedures for hydraulic pressure transducers

    International Nuclear Information System (INIS)

    Kajikawa, Hiroaki; Kobata, Tokihiko

    2014-01-01

    This paper focuses on 0-A-0 pressurization for the calibration of electromechanical pressure gauges in order to obtain reproducible results by various procedures. In 0-A-0 pressurization, pressure is released to atmospheric pressure after finishing each measurement at each calibration pressure, and the output reading at atmospheric pressure is used for offset correction. Pressure gauges are calibrated under various pressure sequence and time interval conditions in the pressure range of 10 MPa to 100 MPa using a fully automated calibration system that uses a pressure balance as the standard device. Results for a quartz Bourdon-type pressure transducer are mainly reported. The hysteresis obtained by 0-A-0 pressurization is found to be nearly one-tenth of that obtained by stepwise pressurization. The effect of the previously applied pressure is less than 10 parts per million even for a random pressure sequence. Key points for calibration procedures are proposed from the calibration results for different time intervals. When the appropriate procedure is used, 0-A-0 pressurization largely reduces the effect of pressurization history, thus yielding highly reproducible calibration results. (paper)

  6. A life under pressure

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; von Holstein-Rathlou, Niels-Henrik

    2012-01-01

    Microvessels live 'a life under pressure' in several ways. In a literal sense, vessels of the microcirculation are exposed to high levels of stress caused primarily by the intravascular pressure head. In a figurative sense, the individual vessel and the microvascular network as a whole must...... continuously strive to meet the changing demands of the surrounding tissue. The 'principle of optimal operation' as formulated by Y. C. Fung states that living tissues adapts structurally through remodelling and growth until a level of tensile and compressive stresses is reached at which tissue performance...... stress component has a huge impact on the state of the vascular wall. It is involved as a unifying factor on vastly different timescales in processes as diverse as acute regulation of vessel diameter, structural vessel remodelling and growth or atrophy of the vascular wall. The aim of this Mini...

  7. Cost-effectiveness analysis of different systolic blood pressure targets for people with a history of stroke or transient ischaemic attack: Economic analysis of the PAST-BP study.

    Science.gov (United States)

    Penaloza-Ramos, Maria Cristina; Jowett, Sue; Barton, Pelham; Roalfe, Andrea; Fletcher, Kate; Taylor, Clare J; Hobbs, Fd Richard; McManus, Richard J; Mant, Jonathan

    2016-10-01

    The PAST-BP trial found that using a lower systolic blood pressure target (disease was associated with a small additional reduction in blood pressure (2.9 mmHg). To determine the cost effectiveness of an intensive systolic blood pressure target (stroke or transient ischaemic attack on general practice stroke/transient ischaemic attack registers in England. A Markov model with a one-year time cycle and a 30-year time horizon was used to estimate the cost per quality-adjusted life year of an intensive target versus a standard target. Individual patient level data were used from the PAST-BP trial with regard to change in blood pressure and numbers of primary care consultations over a 12-month period. Published sources were used to estimate life expectancy and risks of cardiovascular events and their associated costs and utilities. In the base-case results, aiming for an intensive blood pressure target was dominant, with the incremental lifetime costs being £169 lower per patient than for the standard blood pressure target with a 0.08 quality-adjusted life year gain. This was robust to sensitivity analyses, unless intensive blood pressure lowering reduced quality of life by 2% or more. Aiming for a systolic blood pressure target of stroke/transient ischaemic attack in the community, but it is difficult to separate out the impact of the lower target from the impact of more active management of blood pressure. © The European Society of Cardiology 2016.

  8. Intracranial pressure monitoring

    Science.gov (United States)

    ICP monitoring; CSF pressure monitoring ... There are 3 ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is the most accurate monitoring method. To insert an intraventricular catheter, a ...

  9. Intracranial pressure monitoring (image)

    Science.gov (United States)

    Intracranial pressure monitoring is performed by inserting a catheter into the head with a sensing device to monitor the pressure around the brain. An increase in intracranial pressure can cause a decrease in blood flow to ...

  10. High Blood Pressure Facts

    Science.gov (United States)

    ... Stroke Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN High Blood Pressure Facts Recommend on Facebook Tweet Share Compartir On ... Top of Page CDC Fact Sheets Related to High Blood Pressure High Blood Pressure Pulmonary Hypertension Heart Disease Signs ...

  11. High Blood Pressure

    Science.gov (United States)

    ... normal blood pressure 140/90 or higher is high blood pressure Between 120 and 139 for the top number, ... prehypertension. Prehypertension means you may end up with high blood pressure, unless you take steps to prevent it. High ...

  12. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... Print Page Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has high ... weight. How Will I Know if I Have High Blood Pressure? High blood pressure is a silent problem — you ...

  13. Simple device to determine the pressure applied by pressure clips for the treatment of earlobe keloids

    Directory of Open Access Journals (Sweden)

    Aashish Sasidharan

    2015-01-01

    Full Text Available Background: Keloids of the ear are common problems. Various treatment modalities are available for the treatment of ear keloids. Surgical excision with intralesional steroid injection along with compression therapy has the least recurrence rate. Various types of devices are available for pressure therapy. Pressure applied by these devices is uncontrolled and is associated with the risk of pressure necrosis. We describe here a simple and easy to use device to measure pressure applied by these clips for better outcome. Objectives: To devise a simple method to measure the pressure applied by various pressure clips used in ear keloid pressure therapy. Materials and Methods: By using a force sensitive resistor (FSR, the pressure applied gets converted into voltage using electrical wires, resistors, capacitors, converter, amplifier, diode, nine-volt (9V cadmium battery and the voltage is measured using a multimeter. The measured voltage is then converted into pressure using pressure voltage graph that depicts the actual pressure applied by the pressure clip. Results: The pressure applied by different clips was variable. The spring clips were adjustable by slight variation in the design whereas the pressure applied by binder clips and magnet discs was not adjustable. Conclusion: The uncontrolled/suboptimal pressure applied by certain pressure clips can be monitored to provide optimal pressure therapy in ear keloid for better outcome.

  14. Characterization of a Standardized Ex-vivo Porcine Model to Assess Short Term Intraocular Pressure Changes and Trabecular Meshwork Vitality After Pars Plana Vitrectomy with Different Silicone Oil and BSS Tamponades.

    Science.gov (United States)

    Ebner, Martina; Mariacher, Siegfried; Hurst, José; Szurman, Peter; Schnichels, Sven; Spitzer, Martin S; Januschowski, Kai

    2017-08-01

    The aim of this study was to characterize a standardized porcine ex-vivo testing system for intraocular pressure (IOP) monitoring after vitrectomy with different endotamponades. Twenty-four pig eyes, six per endotamponade group were obtained immediately postmortem. After pars plana vitrectomy, vitreous substitutes (silicone oil 1000 mPas, 2000 mPas, 5000 mPas, and Balanced Salt Solution (BSS)) were instillated and IOP was observed over 24-hours. Infusion pumps with Dulbecco's Modified Eagle Medium (DMEM) simulated a constant aqueous humor circulation. A histological examination of the trabecular meshwork with DAPI- and TUNEL-staining was performed to detect the amount of apoptotic cells. TUNEL-assay showed a mean cell death rate of 3.78% (SD ± 1.46%) for silicone oil endotamponades compared to 5.05% (SD ± 2.18%) in BSS group. One-way ANOVA (p = 0.425) showed no significant difference between both groups. Mean IOP in silicone oil endotamponades was 9.50 mmHg (SD ± 1.68 mmHg) at baseline, 13.23 mmHg (SD ± 0.79 mmHg) after 1 hour, 18.46 mmHg (SD ± 2.13 mmHg) after 12 hours and 15.51 mmHg (SD ± 2.82 mmHg) 24 hours after instillation. A comparison of all silicone oil groups (one-way ANOVA, Bonferroni post-hoc test, p = 0.269 to 1.000) didn't reveal significant differences in mean IOP. The standardized ex-vivo porcine model represents an effective alternative to the in-vivo testing in animals. Maintaining the trabecular and uveoscleral outflow pathway enables a pseudo in-vivo analysis.

  15. Organic electronics based pressure sensor towards intracranial pressure monitoring

    Science.gov (United States)

    Rai, Pratyush; Varadan, Vijay K.

    2010-04-01

    The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

  16. Dependence of osmotic pressure on solution properties

    International Nuclear Information System (INIS)

    Fritz, S.J.

    1978-01-01

    Hydrostatic pressure, temperature, salt concentration, and the chemical composition of the salt are parameters affecting solution properties. Pressure and temperature have little effect on osmosis, but osmotic pressure variations due to type of dissolved salt may be significant, especially at high concentrations. For a given salt solution, concentration variations cause large differences in osmotic pressure. A representative difference in concentration across a clay layer in a relatively shallow groundwater system might be 100 to 1,000 ppm. When expressed as ppm NaCl, this difference could cause a head difference of 0.8 to 8 meters of water if one of the rock bodies were closed to fluid escape

  17. Observations of different core water cluster ions Y-(H2O)n (Y = O2, HOx, NOx, COx) and magic number in atmospheric pressure negative corona discharge mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2011-01-01

    Reliable mass spectrometry data from large water clusters Y(-)(H(2)O)(n) with various negative core ions Y(-) such as O(2)(-), HO(-), HO(2)(-), NO(2)(-), NO(3)(-), NO(3)(-)(HNO(3))(2), CO(3)(-) and HCO(4)(-) have been obtained using atmospheric pressure negative corona discharge mass spectrometry. All the core Y(-) ions observed were ionic species that play a central role in tropospheric ion chemistry. These mass spectra exhibited discontinuities in ion peak intensity at certain size clusters Y(-)(H(2)O)(m) indicating specific thermochemical stability. Thus, Y(-)(H(2)O)(m) may correspond to the magic number or first hydrated shell in the cluster series Y(-)(H(2)O)(n). The high intensity discontinuity at HO(-)(H(2)O)(3) observed was the first mass spectrometric evidence for the specific stability of HO(-)(H(2)O)(3) as the first hydrated shell which Eigen postulated in 1964. The negative ion water clusters Y(-)(H(2)O)(n) observed in the mass spectra are most likely to be formed via core ion formation in the ambient discharge area (760 torr) and the growth of water clusters by adiabatic expansion in the vacuum region of the mass spectrometers (≈1 torr). The detailed mechanism of the formation of the different core water cluster ions Y(-)(H(2)O)(n) is described. Copyright © 2010 John Wiley & Sons, Ltd.

  18. Espessura central da córnea e a medida da pressão intra-ocular com diferentes tonômetros Could the central cornea thickness change the intraocular pressure results obtained by different tonometers

    Directory of Open Access Journals (Sweden)

    Priscila Yumi Kitice

    2007-12-01

    observed with IC and PDCT, showing a mean average difference of -0.2. The intraocular pressure data obtained from PDCT showed higher values when compared with GAT, with a mean average difference of -3.1. There are also a statistical significant difference with the IOP measurements with IC and GAT. CONCLUSION: There are a significant difference in IOP measurements obtained by IC, GAT and PCDT when compared with CCT.

  19. Laplace pressure based disjoining pressure isotherm in non symmetric conditions

    Science.gov (United States)

    Huerre, Axel; Valignat, Marie-Pierre; Maggs, A. C.; Theodoly, Olivier; Jullien, Marie-Caroline

    2017-11-01

    Understanding the stability and dynamics of two phase systems, such as foams and emulsions, in porous media is still a challenge for physicists and calls for a better understanding of the intermolecular interactions between interfaces. In a classical approach, these interactions are investigated in the framework of Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory by building disjoining pressure isotherms. This paper reports on a technique allowing the measurement of disjoining pressure isotherms in a thin liquid film squeezed by either a gas or a liquid phase on a solid substrate. We couple a Reflection Interference Contrast Microscopy set-up to a microfluidic channel that sets the disjoining pressure through the Laplace pressure. This simple technique is found to be both accurate and precise. The Laplace pressure mechanism provides extremely stable conditions and offers opportunity for parallelizing experiments by producing several drops in channels of different heights. We illustrate its potential by comparing experimental isotherms for oil—[(water and sodium dodecyl sulfate (SDS)]—glass systems with different models focusing on the electrostatic contribution of the disjoining pressure. The extracted values of the interface potentials are in agreement with the constant surface potential model and with a full computation. The derived SDS surface concentration agrees with values reported in the literature. We believe that this technique is suitable for investigating other working fluids and intermolecular interactions at smaller scales.

  20. Serotonin and Blood Pressure Regulation

    Science.gov (United States)

    Morrison, Shaun F.; Davis, Robert Patrick; Barman, Susan M.

    2012-01-01

    5-Hydroxytryptamine (5-HT; serotonin) was discovered more than 60 years ago as a substance isolated from blood. The neural effects of 5-HT have been well investigated and understood, thanks in part to the pharmacological tools available to dissect the serotonergic system and the development of the frequently prescribed selective serotonin-reuptake inhibitors. By contrast, our understanding of the role of 5-HT in the control and modification of blood pressure pales in comparison. Here we focus on the role of 5-HT in systemic blood pressure control. This review provides an in-depth study of the function and pharmacology of 5-HT in those tissues that can modify blood pressure (blood, vasculature, heart, adrenal gland, kidney, brain), with a focus on the autonomic nervous system that includes mechanisms of action and pharmacology of 5-HT within each system. We compare the change in blood pressure produced in different species by short- and long-term administration of 5-HT or selective serotonin receptor agonists. To further our understanding of the mechanisms through which 5-HT modifies blood pressure, we also describe the blood pressure effects of commonly used drugs that modify the actions of 5-HT. The pharmacology and physiological actions of 5-HT in modifying blood pressure are important, given its involvement in circulatory shock, orthostatic hypotension, serotonin syndrome and hypertension. PMID:22407614

  1. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2010-01-01

    Process monitoring of micro injection moulding (µIM) is of crusial importance to analyse the effect of different parameter settings on the process and to assess its quality. Quality factors related to cavity pressure can provide useful information directly connected with the dyanmics of the process...... as well as with the filling of the cavity by the polymer melt. In this paper, two parameters derived from cavity pressure over time (i.e. pressure work). The influence of four µIM parameters (melt temperature, mould temperature, injection speed, aand packing pressure) on the two pressure-related outputs...

  2. Reproducibility of repeated measurements with the Kikuhime pressure sensor under pressure garments in burn scar treatment.

    Science.gov (United States)

    Van den Kerckhove, Eric; Fieuws, Steffen; Massagé, Patrick; Hierner, Robert; Boeckx, Willy; Deleuze, Jean-Paul; Laperre, Jan; Anthonissen, Mieke

    2007-08-01

    This study investigated the reproducibility of repeated measurements with the Kikuhime pressure sensor under two different types of pressure garments used in the treatment and prevention of scars after burns. Also efficiency of garments was assessed in clinical circumstances by assessing pressure loss and residual pressure after 1 month. Intra- and inter-observer reproducibility and repeated measurements with 1-month time lapse were examined on 55 sites in 26 subjects by means of intra-class correlation coefficients and standard error of measurements. Results showed good to excellent ICC and low SEMs in the two conditions. There was a significant difference in pressure after 1 month between elastic tricot and weft knit garments, although evolution of pressure loss after 1 month was similar. Concerning different locations, there was a significant difference in pressure loss after 1 month between gloves and sleeves with the largest pressure loss for sleeves. Considering these results we concluded that the Kikuhime pressure sensor provides valid and reliable information and can be used in comparative clinical trials to evaluate pressure garments used in burn scar treatment. Secondly, elastic tricot garments in our study tended to have higher clinical pressures but both types of garments had similar pressure loss over time.

  3. "Left ventricular filling pressure(s)" - Ambiguous and misleading terminology, best abandoned.

    Science.gov (United States)

    Peverill, Roger E

    2015-07-15

    The use of the terms "left ventricular filling pressure" and "left ventricular filling pressures" is widespread in the cardiology literature, but the meanings ascribed to these terms have not been consistent. Left ventricular end-diastolic pressure (LVEDP) and mean left atrial pressure (LAP) cannot be used interchangeably as they will often differ in magnitude in the presence of cardiac disease and they also have different clinical significance. LVEDP is the best pressure to use when considering left ventricular function, whereas mean LAP is the most relevant pressure when considering the tendency to pulmonary congestion. The mean LAP is also the most relevant pressure for determining whether pulmonary hypertension has a left heart (post-capillary) component. If only a left ventricular pressure tracing is available then a technique to measure the mean left ventricular diastolic pressure is the best option for estimating the mean LAP. If only right heart pressures are available then the pulmonary artery end-diastolic pressure will provide a reasonable estimate of LVEDP, but only when the heart and pulmonary circulation are normal. If there is mitral valve disease, left ventricular disease or pulmonary hypertension the LVEDP cannot be estimated from right heart pressures. The problem of the ambiguity of "filling pressure (s)" is readily solved by the abandonment of this term and the use of either LVEDP or mean LAP as appropriate. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Low blood pressure

    Science.gov (United States)

    ... Low blood pressure can usually be treated with success. Possible Complications Falls due to low blood pressure ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  5. Atmospheric Pressure Indicator.

    Science.gov (United States)

    Salzsieder, John C.

    1995-01-01

    Discusses observable phenomena related to air pressure. Describes a simple, unobtrusive, semiquantitative device to monitor the changes in air pressure that are associated with altitude, using a soft-drink bottle and a balloon. (JRH)

  6. Pressure surge attenuator

    Science.gov (United States)

    Christie, Alan M.; Snyder, Kurt I.

    1985-01-01

    A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

  7. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... increased? play_arrow What do family members and caregivers need to know about pressure sores? play_arrow What do family members and caregivers need to do to prevent pressure sores? play_ ...

  8. High blood pressure medications

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007484.htm High blood pressure medicines To use the sharing features on this page, please enable JavaScript. Treating high blood pressure will help prevent problems such as heart disease, ...

  9. High blood pressure - children

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007696.htm High blood pressure - children To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  10. High Blood Pressure

    Science.gov (United States)

    ... Immunosuppressant medicines Anxiety, depression and mental health Kidney rejection Lifestyle changes Donate a kidney Being a living ... take a blood pressure medicine. There are many types of blood pressure medicine and you may need to take ...

  11. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Injury Medical Expert Videos Topics menu Topics Preventing Pressure Sores Adult Injuries Spinal Cord Injury 101 David Chen, MD Preventing Pressure Sores Mary Zeigler, MS Transition from Hospital to ...

  12. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... L Sarah Harrison, OT Anne Bryden, OT The Role of the Social Worker after Spinal Cord Injury ... do to prevent pressure sores? play_arrow What role does diet and hydration play in preventing pressure ...

  13. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... to prevent pressure sores? play_arrow What is “skin tolerance” and how can it be ... play_arrow What role does diet and hydration play in preventing pressure sores among ...

  14. Preventing High Blood Pressure

    Science.gov (United States)

    ... Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN Preventing High Blood Pressure: Healthy Living Habits Recommend on Facebook Tweet Share ... meal and snack options can help you avoid high blood pressure and its complications. Be sure to eat plenty ...

  15. High blood pressure - infants

    Science.gov (United States)

    Hypertension - infants ... and blood vessels The health of the kidneys High blood pressure in infants may be due to kidney or ... blood vessel of the kidney) In newborn babies, high blood pressure is often caused by a blood clot in ...

  16. Understanding Blood Pressure Readings

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Understanding Blood Pressure Readings Updated:Feb 19,2018 What do your ... this chart: English | Spanish | Traditional Chinese Enter Your Blood Pressure Systolic mm Hg (upper #) Diastolic mm Hg (lower #) ...

  17. [Cessation of livor in defined pressure conditions].

    Science.gov (United States)

    Fechner, G; Koops, E; Henssge, C

    1984-01-01

    In 28 cases of sudden death, the corpses were tested for the effect of different storage temperatures (5 degrees C, 14 degrees-15 degrees C, 25 degrees C) regarding the reaction of livor mortis to known pressure conditions (force and duration of pressure). The reaction is dependent on the storage temperature but there is no linear relationship. At certain storage temperatures the postmortem lividity reaction is dependent on the amount and duration of the pressure. In addition, at defined storage temperature and pressure conditions, there are large interindividual differences in the estimation of time of death.

  18. High-pressure microbiology

    National Research Council Canada - National Science Library

    Michiels, Chris; Bartlett, Douglas Hoyt; Aertsen, Abram

    2008-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. High Hydrostatic Pressure Effects in the Biosphere: from Molecules to Microbiology * Filip Meersman and Karel Heremans . . . . . . . . . . . . 2. Effects...

  19. PRESSURE SYSTEM CONTROL

    Science.gov (United States)

    Esselman, W.H.; Kaplan, G.M.

    1961-06-20

    The control of pressure in pressurized liquid systems, especially a pressurized liquid reactor system, may be achieved by providing a bias circuit or loop across a closed loop having a flow restriction means in the form of an orifice, a storage tank, and a pump connected in series. The subject invention is advantageously utilized where control of a reactor can be achieved by response to the temperature and pressure of the primary cooling system.

  20. Tunable high pressure lasers

    Science.gov (United States)

    Hess, R. V.

    1976-01-01

    Atmospheric transmission of high energy CO2 lasers is considerably improved by high pressure operation which, due to pressure broadening, permits tuning the laser lines off atmospheric absorption lines. Pronounced improvement is shown for horizontal transmission at altitudes above several kilometers