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Sample records for inter-arm pressure difference

  1. Inter arm systolic blood pressure difference is associated with a high prevalence of cardio vascular diseases

    Directory of Open Access Journals (Sweden)

    Narsingh Verma

    2016-04-01

    Results: The systolic blood pressure on right arm was 118.8+/-11.5 mmHg and 11.7+/-7.72 mmHg left arm. Result significantly showed higher mean systolic blood pressure on right arm. There were 54, 17 and 29 participants with inter-arm systolic blood pressure difference of 30. Out of 100 subjects, 11 subject having inter-arm systolic blood pressure difference and #8805;10 mmHg was associated with a family history of diabetes or hypertension. Conclusions: Presence of inter-arm blood pressure difference with having family history of hypertension or diabetes is more susceptible to develop cardiovascular disorder in future. [Int J Res Med Sci 2016; 4(4.000: 1177-1180

  2. Human immunodeficiency virus infection and inter-arm blood pressure difference

    Institute of Scientific and Technical Information of China (English)

    杨明

    2013-01-01

    Objective To analyze the association between cardiovascular risk factors and inter-arm blood pressure difference(IAD) in patients with human immunodeficiency virus(HIV) infection,and to confirm as to whether HIV infection promotes atherosclerosis. Methods 41 HAART-naive HIV infected-patients and 43 healthy people were

  3. Association of Inter-arm Blood Pressure Difference with Asymptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients

    Science.gov (United States)

    Wang, Yan; Zhang, Jin; Qian, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Li, Yan; Gao, Pingjin; Zhu, Dingliang

    2016-01-01

    Inter-arm blood pressure (BP) difference has been associated with ischemic stroke. Local atherosclerosis of stroke differ among vulnerable individuals, whereas intracranial arterial stenosis (ICAS) is more frequently affected Asians, and extracranial arterial stenosis (ECAS) is more prevalent among whites. We hereby sought to explore the association of inter-arm BP difference with ICAS and ECAS in stroke-free hypertensive patients in Chinese population. All the 885 subjects were evaluated of ICAS and ECAS through computerized tomographic angiography. Both arm BP was measured simultaneously by Vascular Profiler-1000 device. In the continuous study, ICAS was significantly associated with age, male, average brachial SBP, diabetes, anti-hypertensive treatment and inter-arm DBP difference. ECAS was associated with age, inter-arm SBP and LDL. In the categorical study, subjects with the top quartile of inter-arm DBP difference (≥4 mmHg) showed significantly higher risk of ICAS (OR = 2.109; 95% CI, 1.24–3.587). And the participants with the top quartile of inter-arm SBP difference (≥6 mmHg) showed significantly higher risk of ECAS (OR = 2.288; 95% CI, 1.309–3.998). In conclusion, we reported a diverse association of inter-arm SBP/DBP difference with the ICAS/ECAS. Inter-arm DBP difference might be the early symbol of ICAS in Chinese population, which need further verification in long-term cohort study. PMID:27412818

  4. Development and validation of optimal cut-off value in inter-arm systolic blood pressure difference for prediction of cardiovascular events.

    Science.gov (United States)

    Hirono, Akira; Kusunose, Kenya; Kageyama, Norihito; Sumitomo, Masayuki; Abe, Masahiro; Fujinaga, Hiroyuki; Sata, Masataka

    2017-08-19

    An inter-arm systolic blood pressure difference (IAD) is associated with cardiovascular disease. The aim of this study was to develop and validate the optimal cut-off value of IAD as a predictor of major adverse cardiac events in patients with arteriosclerosis risk factors. From 2009 to 2014, 1076 patients who had at least one cardiovascular risk factor were included in the analysis. We defined 700 randomly selected patients as a development cohort to confirm that IAD was the predictor of cardiovascular events and to determine optimal cut-off value of IAD. Next, we validated outcomes in the remaining 376 patients as a validation cohort. The blood pressure (BP) of both arms measurements were done simultaneously using the ankle-brachial blood pressure index (ABI) form of automatic device. The primary endpoint was the cardiovascular event and secondary endpoint was the all-cause mortality. During a median period of 2.8 years, 143 patients reached the primary endpoint in the development cohort. In the multivariate Cox proportional hazards analysis, IAD was the strong predictor of cardiovascular events (hazard ratio: 1.03, 95% confidence interval: 1.01-1.05, p=0.005). The receiver operating characteristic curve revealed that 5mmHg was the optimal cut-off point of IAD to predict cardiovascular events (p<0.001). In the validation cohort, the presence of a large IAD (IAD ≥5mmHg) was significantly associated with the primary endpoint (p=0.021). IAD is significantly associated with future cardiovascular events in patients with arteriosclerosis risk factors. The optimal cut-off value of IAD is 5mmHg. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

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

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    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.

  6. Inter-arm coordination and intra-cyclic variation of the hip velocity during front crawl resisted swimming.

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    Gourgoulis, V; Aggeloussis, N; Boli, A; Michalopoulou, M; Toubekis, A; Kasimatis, P; Vezos, N; Mavridis, G; Antoniou, P; Mavrommatis, G

    2013-12-01

    The aim of the study was to assess the acute effect of front crawl sprint resisted swimming on the inter-arm coordination and the fluctuation of the swimming velocity. Nine female swimmers swam four all-out trials of 25 m, without and with low, moderate and high added resistance. Four camcorders were used to record the underwater movement. The inter-arm coordination was quantified using the index of coordination and the hip intra-cyclic velocity variation was analysed by calculating the coefficient of variation and the difference between the maximum and minimum velocities normalized for the mean stroke cycle velocity. One-way repeated measures analyses of variance showed that swimmers change their inter-arm coordination from a "catch up" toward an "opposition" mode. Concerning the hip horizontal intra-cyclic velocity variation, it was increased significantly during resisted swimming. These findings indicate that although resisted swimming cause an increase in the index of coordination and consequently it could be speculated a better propulsive continuity, the velocity fluctuations of the hip within a stroke cycle are not decreased, probably due to the inability of the swimmers to overcome effectively the concrete added resistances used in this study. Thus, at least concerning its acute effect, the hypothesis that the sprint resisted swimming could led to a technical improvement can not be satisfied.

  7. Pressure difference receiving ears

    DEFF Research Database (Denmark)

    Michelsen, Axel; Larsen, Ole Næsbye

    2007-01-01

    of such pressure difference receiving ears have been hampered by lack of suitable experimental methods. In this review, we review the methods for collecting reliable data on the binaural directional cues at the eardrums, on how the eardrum vibrations depend on the direction of sound incidence, and on how sound...... waves behave in the air spaces leading to the interior surfaces of eardrums. A linear mathematical model with well-defined inputs is used for exploring how the directionality varies with the binaural directional cues and the amplitude and phase gain of the sound pathway to the inner surface...

  8. Influence of swimming speed on inter-arm coordination in competitive unilateral arm amputee front crawl swimmers.

    Science.gov (United States)

    Osborough, Conor D; Payton, Carl J; Daly, Daniel J

    2010-12-01

    This study examined the effect of swimming speed on inter-arm coordination and the inter-relationships between swimming speed, inter-arm coordination, and other stroke parameters, in a group of competitive unilateral arm amputee front crawl swimmers. Thirteen highly-trained swimmers were filmed underwater during a series of 25-m front crawl trials of increasing speed. Arm coordination for both arms was quantified using an adapted version of the Index of Coordination. Inter-arm coordination of the amputee swimmers did not change as swimming speed was increased up to maximum. Swimmers showed significantly more catch-up coordination of their affected-arm compared to their unaffected-arm. When sprinting, the fastest swimmers used higher stroke frequencies and less catch-up of their affected-arm than the slower swimmers. Unilateral arm-amputees used an asymmetrical strategy for coordinating their affected-arm relative to their unaffected-arm to maintain the stable repetition of their overall arm stroke cycle. When sprinting, the attainment of a high stroke frequency is influenced mainly by the length of time the affected-arm is held in a stationary position in front of the body before pulling. Reducing this time delay appears to be beneficial for successful swimming performance. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. 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...

  10. Dependency of radon entry on pressure difference

    Science.gov (United States)

    Kokotti, H.; Kalliokoski, P.; Jantunen, M.

    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.

  11. High sensitivity fiber Bragg grating pressure difference sensor

    Institute of Scientific and Technical Information of China (English)

    Haiwei Fu(傅海威); Junmei Fu(傅君眉); Xueguang Qiao(乔学光)

    2004-01-01

    Based on the effect of fiber Bragg grating (FBG) pressure difference sensitivity enhancement by encapsulating the FBG with uniform strength beam and metal bellows, a FBG pressure difference sensor is proposed, and its mechanism is also discussed. The relationship between Bragg wavelength and the pressure difference is derived, and the expression of the pressure difference sensitivity coefficient is also given. It is indicated that there is good linear relation between the Bragg wavelength shift and the pressure difference of the sensor. The theoretical and experimental pressure difference sensitivity coefficients are 38.67 and 37.6 nm/MPa, which are 12890 and 12533 times of that of the bare FBG, respectively. The pressure difference sensitivity and dynamic range can be easily changed by changing the size, Young's modulus, and Poisson's ratio of the beam and the bellows.

  12. Research experiments on pressure-difference sensors with ferrofluid

    Energy Technology Data Exchange (ETDEWEB)

    Ruican, Hao, E-mail: haoruican@163.com [School of Mechanical Engineering, Beijing Polytechnic, Beijing 100176 (China); Huagang, Liu; Wen, Gong; Na, Zhang [School of Mechanical Engineering, Beijing Polytechnic, Beijing 100176 (China); Ruixiao, Hao [Civil and Architectural Engineering Institute of CCCC-FHEB Co., Ltd., Beijing 101102 (China)

    2016-10-15

    Ferrofluid has distinctive properties and can be applied in many industrial uses, especially in sensors. The principles of pressure-difference sensors with ferrofluid were illustrated and experiments were demonstrated. Four types of ferrofluids with different concentrations were selected for the experiments performed. Then, the parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. Four U tubes with different diameters were designed and built. Experiments were conducted to analyze the impacts of tube diameter and ferrofluid concentration on the output voltage/pressure difference performance. According to the experiment results, the tube diameter has little effect on the sensor output voltage. With the concentration of ferrofluid increasing, the output voltage and sensitivity of the pressure-difference sensor increases. The measurable range of the sensor also increases with the increasing concentration of ferrofluid. The workable range and the sensitivity of the designed sensor were (−2000~+2000)Pa and 1.26 mV/Pa, respectively. - Highlights: • The principle of pressure difference sensor with ferrofluid was illustrated. • The parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. • Four series of U tubes with different diameter were designed and manufactured. • The experiments were made to analyze the factors of the tube diameter and the concentration of ferrofluid on the output-input pressure difference. • The sensitivity of the pressure difference sensor with ferrofluid was studied and the corresponding conclusions were obtained.

  13. Racial differences in hypertension: implications for high blood pressure management.

    Science.gov (United States)

    Lackland, Daniel T

    2014-08-01

    The racial disparity in hypertension and hypertension-related outcomes has been recognized for decades with African Americans with greater risks than Caucasians. Blood pressure levels have consistently been higher for African Americans with an earlier onset of hypertension. Although awareness and treatment levels of high blood pressure have been similar, racial differences in control rates are evident. The higher blood pressure levels for African Americans are associated with higher rates of stroke, end-stage renal disease and congestive heart failure. The reasons for the racial disparities in elevated blood pressure and hypertension-related outcomes risk remain unclear. However, the implications of the disparities of hypertension for prevention and clinical management are substantial, identifying African American men and women with excel hypertension risk and warranting interventions focused on these differences. In addition, focused research to identify the factors attributed to these disparities in risk burden is an essential need to address the evidence gaps.

  14. Regulation of South China Sea throughflow by pressure difference

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    Qin, Huiling; Huang, Rui Xin; Wang, Weiqiang; Xue, Huijie

    2016-06-01

    Sea Surface Height (SSH) data from the European Centre for Medium-Range Weather Forecasts-Ocean Reanalysis System 4 (ECMWF-ORAS4) are used to determine the pressure difference in connection with variability of the South China Sea ThroughFlow (SCSTF) from 1958 to 2007. Two branches of SCSTF, the Karimata-Sunda Strait ThroughFlow (KSSTF) and the Mindoro Strait ThroughFlow (MSTF), are examined. Using the ensemble empirical mode decomposition method (EEMD), time series of pressure difference and volume transport are decomposed into intrinsic mode functions and trend functions, with the corresponding variability on different time scales. Pressure difference agrees with the KSSTF volume transport on decadal time scale; while for the MSTF, pressure difference varies similarly with volume transport on interannual time scale. Separating the dynamic height difference into the thermal and haline terms, for the KSSTF more than half of the dynamic height difference (32 cm) is due to the thermal contributions; while the remaining dynamic height difference (23 cm) is due to the haline contributions. For the MSTF, the dynamic height difference (29 cm) is primarily due to the thermal contribution (26 cm).

  15. Plantar Pressure Variation during Jogging with Different Heel Height

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    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.

  16. Comparison of unsteady pressure fields on turrets with different surface features using pressure-sensitive paint

    Science.gov (United States)

    Gordeyev, Stanislav; De Lucca, Nicholas; Jumper, Eric J.; Hird, Kyle; Juliano, Thomas J.; Gregory, James W.; Thordahl, James; Wittich, Donald J.

    2014-01-01

    Spatially temporally resolved unsteady pressure fields on a surface of a hemisphere-on-cylinder turret with either a flat or a conformal window with realistic features such as gaps and "smile" cutouts were characterized using fast-response pressure-sensitive paint at M = 0.33 for several window viewing angles. Various statistical properties of pressure fields were computed, and geometry effects on the unsteady pressure fields were analyzed and discussed. Proper orthogonal decomposition was also used to extract dominant pressure modes and corresponding temporal coefficients and to analyze and compare instantaneous pressure structures for different turret geometric features and the window viewing angles. An unsteady separation off the turret and a recirculation region downstream of the turret were identified as dominant sources of the unsteady pressure. It was found that while all geometric features affected the unsteady pressure field, the "smiles," positioned spanwise-symmetrically on both sides of the turret, were the leading cause of these changes, followed by the looking forward flat window. The gaps, the side- and the back-looking flat window introduced only small local changes.

  17. Sex differences in pressure diuresis/natriuresis in rabbits.

    Science.gov (United States)

    Evans, R G; Stevenson, K M; Bergström, G; Denton, K M; Madden, A C; Gribben, R L; Weekes, S R; Anderson, W P

    2000-08-01

    We tested for sex-related differences in the pressure diuresis/natriuresis relationships in anaesthetized, renally denervated rabbits, using an extracorporeal circuit to perfuse the left kidney with the rabbit's own blood, through a series of step-wise increases in renal artery pressure (RAP) (from 65 to 130 mmHg). Urine flow, sodium excretion, and the fractional excretions of sodium and urine increased with increasing RAP, and were greater in male than in female rabbits at all levels of RAP-tested. However, these apparent sex-related differences in the acute pressure diuresis/natriuresis relationships were not reflected in alterations in chronic regulation of mean arterial pressure (MAP). Thus, in rabbits on a normal salt diet (0.85 g day(-1)), resting conscious MAP was significantly greater in males (87 +/- 3 mmHg) compared with females (77+/-1 mmHg). Chronically increasing daily salt intake to 4.98 g day(-1) for 28 days had no significant effect on resting conscious MAP in either sex. Thus, although our observations indicate sex differences, at least under the present experimental conditions, in the factors regulating extracellular fluid volume, these do not appear to have a major impact in setting the level of MAP in the long term.

  18. Research experiments on pressure-difference sensors with ferrofluid

    Science.gov (United States)

    Ruican, Hao; Huagang, Liu; Wen, Gong; Na, Zhang; Ruixiao, Hao

    2016-10-01

    Ferrofluid has distinctive properties and can be applied in many industrial uses, especially in sensors. The principles of pressure-difference sensors with ferrofluid were illustrated and experiments were demonstrated. Four types of ferrofluids with different concentrations were selected for the experiments performed. Then, the parameters of ferrofluid, such as density and magnetization, were measured. The magnetization curves of the ferrofluid were sketched. Four U tubes with different diameters were designed and built. Experiments were conducted to analyze the impacts of tube diameter and ferrofluid concentration on the output voltage/pressure difference performance. According to the experiment results, the tube diameter has little effect on the sensor output voltage. With the concentration of ferrofluid increasing, the output voltage and sensitivity of the pressure-difference sensor increases. The measurable range of the sensor also increases with the increasing concentration of ferrofluid. The workable range and the sensitivity of the designed sensor were (-2000~+2000)Pa and 1.26 mV/Pa, respectively.

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

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    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.

  20. 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.

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

    CERN Document Server

    Xiong, Hao; 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 on the pump power. Further calculation shows that difference-sideband generation can be greatly enhanced via achieving the matching conditions. The effect of difference-sideband generation, which may have potential application for manipulation of light, is especially suited for on-chip optomechanical devices, where nonlinear optomechanical interaction in the weak coupling regime is within current experimental reach.

  2. [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.

  3. 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

  4. Center of pressure trajectory differences between shod and barefoot running.

    Science.gov (United States)

    Becker, James; Pisciotta, Eric; James, Stan; Osternig, Louis R; Chou, Li-Shan

    2014-09-01

    This study examined differences in center of pressure (COP) trajectories between shod and barefoot running. Ten habitually shod runners ran continuous laps under both shod and barefoot conditions. The COP trajectory was calculated in the global coordinate system but then transformed to the anatomic coordinate system of the foot. The anterior-posterior and medio-lateral positions and excursions of the COP, as well as the most medial location and percent stand at which it occurred were examined. Additionally, external eversion moments and ground reaction forces were assessed. Compared to the shod condition, in the barefoot condition the COP was located more anteriorly early in stance and the COP was located significantly more medially at most time points across stance. There were no differences in external eversion moments during early stance or peak ground reaction forces between conditions. Future studies on mechanical or epidemiological differences between shod and barefoot running may find the COP trajectory an informative parameter to examine.

  5. Systolic Pressure in Different Percents of Stenosis at Major Arteries

    CERN Document Server

    Mirzaee, Mohammad Reza; Firoozabadi, Bahar; Dandaneband, Meitham

    2016-01-01

    - Modeling Human cardiovascular system is always an important issue. One of the most effective methods is using lumped model to reach to a complete model of human cardiovascular system. Such modeling with advanced considerations is used in this paper. Some of these considerations are as follow: Exact simulating of ventricles as pressure suppliers, peristaltic motion of descending arteries as additional suppliers, and dividing each vessel into more than one compartment to reach more accurate answers. Finally a circuit with more than 150 RLC segments and different elements is made. Then the verification of our complex circuit is done and at the end, obstruction as an important abnormality is investigated. For this aim different percents of obstruction in vital arteries are considered and the results are brought as different graphs at the end. According to physiological texts the citation of our simulation and its results are obvious. To earn productive information about arteries characteristics a 36-vessels mod...

  6. Different origins of garnet in high pressure to ultrahigh pressure metamorphic rocks

    Science.gov (United States)

    Xia, Qiong-Xia; Zhou, Li-Gang

    2017-09-01

    Garnet in high-pressure (HP) to ultrahigh-pressure (UHP) metamorphic rocks in subduction zone commonly shows considerable zonation in major and trace elements as well as mineral inclusions, which bears information on its growth mechanism via metamorphic or peritectic reactions in coexistence with relic minerals and metamorphic fluids or anatectic melts at subduction-zone conditions. It provides an important target to retrieve physicochemical changes in subduction-zone processes, including those not only in pressure and temperature but also in the durations of metamorphism and anatexis. Garnet from different compositions of HP to UHP metamorphic rocks may show different types of major and trace element zonation, as well as mineral inclusions. Discrimination between the different origins of garnet provides important constraints on pressure and temperature and the evolution history for the HP to UHP metamorphic rocks. Magmatic garnet may occur as relics in granitic gneisses despite metamorphic modification at subduction-zone conditions, with spessartine-increasing or flat major element profiles from inner to outer core and exceptionally higher contents of trace elements than metamorphic mantle and rim. Metamorphic garnet can grow at different metamorphic stages during prograde subduction and retrograde exhumation, with spessartine-decreasing from core to rim if the intracrystalline diffusion is not too fast. The compositional profiles of metamorphic garnet in the abundances of grossular, almandine and pyrope are variable depending on the composition of host rocks and co-existing minerals. Peritectic garnet grows through peritectic reactions during partial melting of HP to UHP rocks, with the composition of major elements to be controlled by anatectic P-T conditions and the compositions of parental rocks and anatectic melts. Trace element profiles in garnet with different origins are also variable depending on the coexisting mineral assemblages, the garnet

  7. Different Selection Pressures Give Rise to Distinct Ethnic Phenomena

    Science.gov (United States)

    Moya, Cristina; Boyd, Robert

    2015-01-01

    Many accounts of ethnic phenomena imply that processes such as stereotyping, essentialism, ethnocentrism, and intergroup hostility stem from a unitary adaptation for reasoning about groups. This is partly justified by the phenomena’s co-occurrence in correlational studies. Here we argue that these behaviors are better modeled as functionally independent adaptations that arose in response to different selection pressures throughout human evolution. As such, different mechanisms may be triggered by different group boundaries within a single society. We illustrate this functionalist framework using ethnographic work from the Quechua-Aymara language boundary in the Peruvian Altiplano. We show that different group boundaries motivate different ethnic phenomena. For example, people have strong stereotypes about socioeconomic categories, which are not cooperative units, whereas they hold fewer stereotypes about communities, which are the primary focus of cooperative activity. We also show that, despite the cross-cultural importance of ethnolinguistic boundaries, the Quechua-Aymara linguistic distinction does not strongly motivate any of these intergroup processes. PMID:25731969

  8. 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.

  9. Genes influencing circadian differences in blood pressure in hypertensive mice.

    Directory of Open Access Journals (Sweden)

    Francine Z Marques

    Full Text Available Essential hypertension is a common multifactorial heritable condition in which increased sympathetic outflow from the central nervous system is involved in the elevation in blood pressure (BP, as well as the exaggerated morning surge in BP that is a risk factor for myocardial infarction and stroke in hypertensive patients. The Schlager BPH/2J mouse is a genetic model of hypertension in which increased sympathetic outflow from the hypothalamus has an important etiological role in the elevation of BP. Schlager hypertensive mice exhibit a large variation in BP between the active and inactive periods of the day, and also show a morning surge in BP. To investigate the genes responsible for the circadian variation in BP in hypertension, hypothalamic tissue was collected from BPH/2J and normotensive BPN/3J mice at the 'peak' (n = 12 and 'trough' (n = 6 of diurnal BP. Using Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays, validation by quantitative real-time PCR and a statistical method that adjusted for clock genes, we identified 212 hypothalamic genes whose expression differed between 'peak' and 'trough' BP in the hypertensive strain. These included genes with known roles in BP regulation, such as vasopressin, oxytocin and thyrotropin releasing hormone, as well as genes not recognized previously as regulators of BP, including chemokine (C-C motif ligand 19, hypocretin and zinc finger and BTB domain containing 16. Gene ontology analysis showed an enrichment of terms for inflammatory response, mitochondrial proton-transporting ATP synthase complex, structural constituent of ribosome, amongst others. In conclusion, we have identified genes whose expression differs between the peak and trough of 24-hour circadian BP in BPH/2J mice, pointing to mechanisms responsible for diurnal variation in BP. The findings may assist in the elucidation of the mechanism for the morning surge in BP in essential hypertension.

  10. Genes influencing circadian differences in blood pressure in hypertensive mice.

    Science.gov (United States)

    Marques, Francine Z; Campain, Anna E; Davern, Pamela J; Yang, Yee Hwa J; Head, Geoffrey A; Morris, Brian J

    2011-04-26

    Essential hypertension is a common multifactorial heritable condition in which increased sympathetic outflow from the central nervous system is involved in the elevation in blood pressure (BP), as well as the exaggerated morning surge in BP that is a risk factor for myocardial infarction and stroke in hypertensive patients. The Schlager BPH/2J mouse is a genetic model of hypertension in which increased sympathetic outflow from the hypothalamus has an important etiological role in the elevation of BP. Schlager hypertensive mice exhibit a large variation in BP between the active and inactive periods of the day, and also show a morning surge in BP. To investigate the genes responsible for the circadian variation in BP in hypertension, hypothalamic tissue was collected from BPH/2J and normotensive BPN/3J mice at the 'peak' (n = 12) and 'trough' (n = 6) of diurnal BP. Using Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays, validation by quantitative real-time PCR and a statistical method that adjusted for clock genes, we identified 212 hypothalamic genes whose expression differed between 'peak' and 'trough' BP in the hypertensive strain. These included genes with known roles in BP regulation, such as vasopressin, oxytocin and thyrotropin releasing hormone, as well as genes not recognized previously as regulators of BP, including chemokine (C-C motif) ligand 19, hypocretin and zinc finger and BTB domain containing 16. Gene ontology analysis showed an enrichment of terms for inflammatory response, mitochondrial proton-transporting ATP synthase complex, structural constituent of ribosome, amongst others. In conclusion, we have identified genes whose expression differs between the peak and trough of 24-hour circadian BP in BPH/2J mice, pointing to mechanisms responsible for diurnal variation in BP. The findings may assist in the elucidation of the mechanism for the morning surge in BP in essential hypertension.

  11. Morning blood pressure surge: the reliability of different definitions.

    Science.gov (United States)

    Stergiou, George S; Mastorantonakis, Stylianos E; Roussias, Leonidas G

    2008-08-01

    Preliminary evidence suggests that the morning surge (MS) in blood pressure (BP) is an independent predictor of cerebrovascular disease. However, the optimal definition of MS is uncertain. To compare the reproducibility of several MS definitions used in the literature, 132 untreated hypertensives were assessed with ambulatory BP monitoring twice, 2 weeks apart. Five MS definitions were compared. MS-1: the average BP of the first hour after rising minus the average BP of the first hour before rising; MS-2: BP 2 h after rising minus that of 2 h before rising; MS-3: BP 3 h after rising minus that of 3 h before rising; MS-4: BP 2 h after rising minus the average BP during sleep; MS-5: BP 2 h after rising minus the average BP of 3 consecutive readings, centered on the lowest reading during sleep. The reproducibility of each MS definition was assessed using the concordance correlation coefficient (CCC), the standard deviation of differences (SDD) and the coefficient of variation (CV) between repeated MS assessments, and the agreement in detecting "surgers," defined as subjects at the top quartile (Q4) of the MS distribution. CCCs were 0.20/0.30, 0.43/0.45, 0.53/0.51, 0.51/0.47, and 0.46/0.48 (systolic/diastolic) for MS-1 to MS-5 respectively; SDDs were 14.3/11.4, 12.1/9.9, 11.2/9.5, 10.3/8.2, and 11.9/9.8, respectively; CVs were 0.49/0.57, 0.44/0.39, 0.37/0.35, 0.36/0.31, and 0.27/0.24, respectively; and the agreement in detecting "surgers" was 69%/70%, 71%/76%, 75%/75%, 81%/83%, and 74%/75%, with kappa of 0.18/0.20, 0.23/0.36, 0.33/0.33, 0.49/0.53 and 0.29/0.31, respectively. There are important differences in the reproducibility of MS calculated by different methods. MS4 appears to provide the most reproducible definition of MS.

  12. The nature of bubble growth under different system pressures in a narrow channel

    Energy Technology Data Exchange (ETDEWEB)

    Chen Deqi [School of Power Engineering, Chongqing University, Chongqing, Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing 400044 (China); Pan Liangming, E-mail: cneng@cqu.edu.c [School of Power Engineering, Chongqing University, Chongqing, Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing 400044 (China); Yuan Dewen; Zhang Hui [School of Power Engineering, Chongqing University, Chongqing, Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing 400044 (China); Xu Jianhui; Huang Yanping [Institute of Nuclear Power of China, Chengdu 610041 (China)

    2011-03-15

    Research highlights: We find that Sliding bubble growth occurs under higher system pressure (6-10 bar). The heat transfer situation is quite different under different system pressure. The latent heat needed for a bubble increases with increasing system pressure. So the bubble size and bubble growth rate decrease with increasing system pressure. Also a method for non-dimensionalizing the bubble radius and growth time is proposed. - Abstract: Bubble growth in a vertical narrow channel under different system pressures (1-10 bar) was photographically studied. It was found that bubble growth rates and bubble sizes decrease with increasing system pressures. It was also found that bubbles grow at nucleate sites and begin to shrink due to condensation after departing from nucleate sites under lower system pressures (1-3 bar). However, bubbles keep growing along the heating wall under higher system pressures (6-10 bar). All bubble growth curves under different system pressures can be predicted by power curve model in the present study. A theoretical analysis on the effect of system pressure on bubble growth shows that the latent heat needed for a bubble with unit volume and the heat transfer on the heating wall are quite different under different system pressures, which results in distinct difference in bubble growth under different system pressure.

  13. Response of an artificially blown clarinet to different blowing pressure profiles

    CERN Document Server

    Bergeot, Baptiste; Vergez, Christophe; Gazengel, Bruno; Didier, Ferrand

    2013-01-01

    Using an artificial mouth with an accurate pressure control, the onset of the pressure oscillations inside the mouthpiece of a simplified clarinet is studied experimentally. Two time profiles are used for the blowing pressure: in a first set of experiments the pressure is increased at constant rates, then decreased at the same rate. In a second set of experiments the pressure rises at a constant rate and is then kept constant for an arbitrary period of time. In both cases the experiments are repeated for different increase rates. Numerical simulations using a simplified clarinet model blown with a constantly increasing mouth pressure are compared to the oscillating pressure obtained inside the mouthpiece. Both show that the beginning of the oscillations appears at a higher pressure values than the theoretical static threshold pressure, a manifestation of bifurcation delay. Experiments performed using an interrupted increase in mouth pressure show that the beginning of the oscillation occurs close to the stop ...

  14. Evaluation of intraperitoneal pressure and the effect of different osmotic agents on intraperitoneal pressure in children.

    NARCIS (Netherlands)

    Rusthoven, E.; Vlugt, M.E. van der; Lingen-van Bueren, L.J. van; Schaijk, T.C. van; Willems, H.L.; Monnens, L.A.H.; Schroder, C.H.

    2005-01-01

    OBJECTIVES: To establish intraperitoneal pressure (IPP) in a relatively large pediatric study group and to study the effects of a 3.86% glucose solution and a 7.5% icodextrin solution on IPP during a 4-hour dwell. DESIGN: IPP was measured with the patient in a supine position. The intraperitoneal vo

  15. 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…

  16. Plastic Limit Load Analysis of Cylindrical Pressure Vessels with Different Nozzle Inclination

    Science.gov (United States)

    Prakash, Anupam; Raval, Harit Kishorchandra; Gandhi, Anish; Pawar, Dipak Bapu

    2016-04-01

    Sudden change in geometry of pressure vessel due to nozzle cutout, leads to local stress concentration and deformation, decreasing its strength. Elastic plastic analysis of cylindrical pressure vessels with different inclination angles of nozzle is important to estimate plastic limit load. In the present study, cylindrical pressure vessels with combined inclination of nozzles (i.e. in longitudinal and radial plane) are considered for elastic plastic limit load analysis. Three dimensional static nonlinear finite element analyses of cylindrical pressure vessels with nozzle are performed for incremental pressure loading. The von Mises stress distribution on pressure vessel shows higher stress zones at shell-nozzle junction. Approximate plastic limit load is obtained by twice elastic slope method. Variation in limit pressure with different combined inclination angle of nozzle is analyzed and found to be distinct in nature. Reported results can be helpful in optimizing pressure vessel design.

  17. High hydrostatic pressure tolerance of four different anhydrobiotic animal species.

    Science.gov (United States)

    Horikawa, Daiki D; Iwata, Ken-Ichi; Kawai, Kiyoshi; Koseki, Shigenobu; Okuda, Takashi; Yamamoto, Kazutaka

    2009-03-01

    High hydrostatic pressure (HHP) can induce physical changes in DNA, proteins, and lipids, causing lethal or sublethal damage to organisms. However, HHP tolerance of animals has not been studied sufficiently. In this study, HHP tolerance of four species of invertebrate anhydrobiotes (the tardigrade Milnesium tardigradum, a nematode species in the family Plectidae, larvae of Polypedilum vanderplanki, and cysts of Artemia franciscana), which have the potential to enter anhydrobiosis upon desiccation, were investigated by exposing them to 1.2 GPa for 20 minutes. This exposure killed the anhydrobiotes in their ordinary hydrated state, but did not affect their survival in the anhydrobiotic state. The results indicated that the hydrated anhydrobiotes were vulnerable to HHP, but that HHP of 1.2 GPa was not sufficient to kill them in anhyrdobiosis.

  18. PERFUSION PRESSURE AND RENAL BLOOD FLOW: THEIR RELATIONSHIP AND DIFFERENCES

    Directory of Open Access Journals (Sweden)

    Carlos G. Musso, MD. PhD.1,2, Manuel Vilas, MD.

    2014-05-01

    Full Text Available The concepts of renal perfusion pressure (RPP and renal blood flow (RBF are usually confused, but although they are intimately related, they are not strictly the same. RPP originates from the minute cardiac volume and is, therefore, the cause of RBF, which generates glomerular filtration and as a consequence, also induces the urinary flow. On the other hand, whereas RPP can be subject to fluctuations, the same happens to RBF though at a much lower level due to the existence of physiological mechanisms, such as self-regulation of the flow and tubule-glomerular feed-back. We conclude that there is a dependence of the RBF in relation with RPP, with the former acting as the final responsible of the glomerular filtration.

  19. 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.

  20. Electronic and elastic properties of Li{sub 3}N under different pressure

    Energy Technology Data Exchange (ETDEWEB)

    Li Wei, E-mail: tolwwt@163.co [Laboratory of Quantum Information Technology, School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Chen Junfang [Laboratory of Quantum Information Technology, School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Wang Teng [School of Computer, South China Normal University, 510631 Guangzhou (China)

    2010-01-01

    The electronic structures and elastic properties of lithium nitride are studied using first-principles calculations. The energy band structure and density of state (DOS) of Li{sub 3}N at 0 GPa are calculated. The band gap energy of Li{sub 3}N versus the pressure 0-38.8 GPa is obtained. We find that the band gap energy decreases as the pressure increases. The geometry optimized structural parameters for lithium nitride under different pressures are listed. The parameters a, c, and E all decrease with increasing pressure. However, parameter B, S and Y increase with pressure. The normalized lattice constants and the elastic modulus as two functions of pressure from 0 to 38.8 GPa are obtained. All the calculated elastic constants C{sub ij} increase by different rates with increasing pressure.

  1. Pressure stability of lipases and their use in different systems

    OpenAIRE

    Knez, Željko; Leitgeb, Maja

    2015-01-01

    For the investigation of the solvent impact on the enzymes, lipases from different sources (Pseudomonas fluorescences, Rhizopus javanicus, Rhizopus niveus, Candida rugose and Porcine pancreas) were used. Stability and activity of these lipases in aqueous medium in supercritical $CO_2$ and liquid propane at 100 bar and 40°C were studied. On the basis of previous results lipases were used for their application in two different systems. The application of the polysulphone membrane in the cont...

  2. 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.

  3. [Features of arterial blood pressure in elderly persons of different ethnic groups in Yakutsk].

    Science.gov (United States)

    Nikitin, Iu P; Tatarinova, O V; Neustroeva, V N; Shcherbakova, L V; Sidorov, A S

    2013-01-01

    The differences in arterial blood pressure in the sample of population in the age of 60 and older of different ethnic groups in Yakutsk, as well as its connection with the other cardiovascular diseases risk factors have been analyzed. It was shown that the average values of systolic and diastolic blood pressure in subsample of the Yakuts appeared to be lower than in Caucasoid gerontic persons. The average values of systolic arterial blood pressure both in the Yakuts and in the Caucasoids were detected higher than normal values in all age-dependent subgroups. The average values of diastolic blood pressure in both ethnic groups were within the limits of high normal level. From 60 to 90 years and older the decrease in systolic and diastolic arterial blood pressure was detected; it was more marked in Caucasoid gerontic persons. The average values of pulse pressure in the Yakuts and in the Caucasoids appeared to be higher than the existing standard and didn't have any differences in ethnic groups. In both ethnical subsamples, pulse pressure values increase was observed in persons of 60-89 years old and its decrease after 90. Persons with overweight, obesity, central (abdominal) obesity, dyslypoproteidemias irrespective of belonging to ethnical group were characterized as having higher levels of arterial blood pressure. Statistically significant differences in the levels of arterial blood pressure in the Yakuts and in the Caucasoids depending on hyperglycemia, smoking, the presence of burdened anamnesis, educational level, marital status was not detected.

  4. Adsorption mechanism of different coal ranks under variable temperature and pressure conditions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-ling

    2008-01-01

    Variable temperature and pressure adsorption tests were conducted on four coal samples with different coal ranks, under simulated temperatures and pressures corresponding to coal reservoirs at different depths. The regularity of the variation in the amounts of adsorption by coals under variable temperature and pressure and 30 ~C isothermal conditions are compared and the adsorption characteristics of coal under the composite effect of temperature and pressure were obtained. The adsorption test and data processing method of coal under variable temperature and pressure are presented and the effect of the mechanism of tempera-ture and pressure on the adsorption capacity of coal has been studied. The research results are of significant importance in the in-vestigation of coalbed methane storage mechanism and for the prediction of the amounts of coalbed methane at various depths.

  5. 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:

  6. Mechanisms of surface pressure distribution within a laminar separation bubble at different Reynolds numbers

    Science.gov (United States)

    Lee, Donghwi; Kawai, Soshi; Nonomura, Taku; Anyoji, Masayuki; Aono, Hikaru; Oyama, Akira; Asai, Keisuke; Fujii, Kozo

    2015-02-01

    Mechanisms behind the pressure distribution and skin friction within a laminar separation bubble (LSB) are investigated by large-eddy simulations around a 5% thickness blunt flat plate at the chord length based Reynolds number 5.0 × 103, 6.1 × 103, 1.1 × 104, and 2.0 × 104. The characteristics inside the LSB change with the Reynolds number; a steady laminar separation bubble (LSB_S) at the Reynolds number 5.0 × 103 and 6.1 × 103, and a steady-fluctuating laminar separation bubble (LSB_SF) at the Reynolds number 1.1 × 104, and 2.0 × 104. Different characteristics of pressure and skin friction distributions are observed by increasing the Reynolds number, such that a gradual monotonous pressure recovery in the LSB_S and a plateau pressure distribution followed by a rapid pressure recovery region in the LSB_SF. The reasons behind the different characteristics of pressure distributions at different Reynolds numbers are discussed by deriving the Reynolds averaged pressure gradient equation. It is confirmed that the viscous stress distributions near the surface play an important role in determining the formation of different pressure distributions. Depending on the Reynolds numbers, the viscous stress distributions near the surface are affected by the development of a separated laminar shear layer or the Reynolds shear stress. In addition, we show that the same analyses can be applied to the flows around a NACA0012 airfoil.

  7. 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.

  8. 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. Howev

  9. Thermal power transfer system using applied potential difference to sustain operating pressure difference

    Science.gov (United States)

    Bhandari, Pradeep (Inventor); Fujita, Toshio (Inventor)

    1991-01-01

    A thermal power transfer system using a phase change liquid gas fluid in a closed loop configuration has a heat exchanger member connected to a gas conduit for inputting thermal energy into the fluid. The pressure in the gas conduit is higher than a liquid conduit that is connected to a heat exchanger member for outputting thermal energy. A solid electrolyte member acts as a barrier between the gas conduit and the liquid conduit adjacent to a solid electrolyte member. The solid electrolyte member has the capacity of transmitting ions of a fluid through the electrolyte member. The ions can be recombined with electrons with the assistance of a porous electrode. An electrical field is applied across the solid electrolyte member to force the ions of the fluid from a lower pressure liquid conduit to the higher pressure gas conduit.

  10. Heat Transfer From Electrically Heated Nichrome Wires to Boiling Water at Different Pressures

    Directory of Open Access Journals (Sweden)

    Devi Dayal

    1968-01-01

    Full Text Available Boiling curves for nucleate and film boiling have been drawn for nichrome of three sizes in distilled and degasified water at saturation temperatures under five different sub-atmospheric vapour pressure. It has been observed that (i for the same Q/A (heat transfer, Delta Theta (excess of wire temperature over saturation point of water decreases with pressure in both nucleate and film boiling ranges, (ii Both Q/A max. and Delta Theta/SubC show a rapid decrease with pressure but these variations become more gradual at higher pressures, and (iii Q/A max. and Delta Theta/SubC increase with wire size at all pressures; increase in Delta Theta/SubC however, becomes less conspicuous at higher pressures approaching one atmosphere.

  11. An Inexpensive Arterial Pressure Wave Sensor and its application in different physiological condition

    CERN Document Server

    Sur, S; Sur, Shantanu

    2005-01-01

    Arterial Blood Pressure wave monitoring is considered to be important in assessment of cardiovascular system. We developed a novel pulse wave detection system using low frequency specific piezoelectric material as pressure wave sensor. The transducer detects the periodic change in the arterial wall diameter produced by pressure wave and the amplified signal after integration represents the pressure wave. The signal before integration is proportional to the rate of change of pressure wave and it not only reproduces the pressure waveform faithfully, but also its sharper nature helps to reliably detect the heart period variability (HPV). We have studied the position-specific (e.g. over carotid or radial artery) nature of change of this pulse wave signal (shape and amplitude) and also the changes at different physiological states.

  12. Differences in hydraulic pressure producing efficiency of front suspension units for motorcycles due to structural difference

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, Tsutomu; Namazue, Eitaro; Ueno, Yutaka

    1995-12-31

    The front suspension unit for motorcycles is one of the functional parts for which continuous engineering improvement is required for advanced driveability. Especially, the ones for off-road motocross racing are frequently required to have their energy absorbing properties, ability to maintain tire-to-ground contact, driving comfort, etc. to be improved to meet the challenges of the racing courses which include many jumps, to exceed the performance of competitors, and to match the ever-improving performance of the engines and frames. To cope with the situation, the operability, rigidity and hydraulic pressure producing mechanism needs to be upgraded. As part of an improvement program, the authors have developed a air-oil separated front suspension which the authors have called the ``twin chamber`` suspension. In this study, the authors compared the hydraulic pressure producing efficiency of the air-oil separated suspension with that of the conventional single chamber construction. The results of the comparison showed that the twin chamber suspension is less affected by the pressure hysteresis by 8% or more at the piston area and 50% or more at the partition area than the conventional suspension. In addition, for the twin chamber suspension, the rise of pressure becomes smoother to give a quicker response as the velocity increases.

  13. Pressure testing of ophthalmic safety lenses: the effects on different materials.

    Science.gov (United States)

    Dain, S J

    1988-07-01

    The procedure of applying pressure to a lens until fracture occurs and the use of the fracture pressure as a measure of lens strength has been proposed as a quantitative alternative to the drop ball test. The fracture pressure or pressure resistance of untempered, thermally tempered, and chemically tempered glass lenses and CR39 lenses were compared. The results for the glass lenses were consistent with workplace experience and previous studies using the drop ball test. The results for glass and CR39 lenses showed the reverse to what was expected. In order to investigate the basis of this difference, a second procedure was followed in which the annulus supporting the lens and the steel ball applying the pressure to the lens were systematically changed. Glass lenses showed a highly statistically significant change in fracture pressure with decreasing ball size and a small but statistically significant change with annulus size. CR39 lenses showed no statistically significant change in fracture pressure with changing ball size but a highly statistically significant increase in fracture pressure with increasing annulus size. The mechanism of fracture is known to differ in the glass and plastics materials and it is concluded that this method should not be used to compare the performance of different materials.

  14. 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

  15. Studies on threshold pressures of sonoluminescence for bubbles with different noble gases

    Institute of Scientific and Technical Information of China (English)

    DING; Chunfeng; XING; Da

    2004-01-01

    The noble gases inside bubbles may have a profound effect on the threshold pressure of sonoluminescence (SL). In this work, the SL threshold pressures have been measured experimentally for bubbles with different noble gases. Results show that the threshold pressure increases with the decrease of molecular mass for gases inside the bubbles. The simulating temperature values at the collapse are almost equal to each other for different gas bubbles at the threshold pressures. However, when the pressure is above the threshold one, the SL mechanism satisfies the bremsstrahlung. On the basis of the experiments and simulations, we found that firstly water molecules dissociate in the process of cavitation and light emission follows; then, the noble gases ionize with the increase of temperature and the bremsstrahlung occurs. SL is a process from molecular emission to bremsstrahlung.

  16. Lower limb intracast pressures generated by different types of immobilisation casts

    Science.gov (United States)

    Chaudhury, Salma; Hazlerigg, Alexandra; Vusirikala, Anuhya; Nguyen, Joseph; Matthews, Stuart

    2017-01-01

    AIM To determine if complete, split casts and backslabs [plaster of Paris (POP) and fiberglass] generate different intracast pressures and pain. METHODS Increased swelling within casts was modeled by a closed water system attached to an expandable bag placed directly under different types of casts applied to a healthy lower limb. Complete fiberglass and POP casts, split casts and backslabs were applied. Twenty-five milliliter aliquots of saline were injected into the system and the generated intracast pressures were measured using a sphygmomanometer. The subject was blinded to the pressure scores to avoid bias. All casts were applied to the same right limb on the same subject to avoid the effects of variations in anatomy or physiology on intracast pressures. Pain levels were evaluated using the Visual Analogue Score after each sequential saline injection. Each type of cast was reapplied four times and the measurements were repeated on four separate occasions. Sample sizes were determined by a pre-study 90% power calculation to detect a 20% difference in intracast pressures between cast groups. RESULTS A significant difference between the various types of casts was noted when the saline volume was greater than 100 mL (P = 0.009). The greatest intracast pressure was generated by complete fiberglass casts, which were significantly higher than complete POP casts or backslabs (P = 0.018 and P = 0.008 respectively) at intracast saline volumes of 100 mL and higher. Backslabs produced a significantly lower intracast pressure compared to complete POP only once the saline volume within casts exceeded 225 mL (P = 0.009). Intracast pressures were significantly lower in split casts (P = 0.003). Split POP and fiberglass casts produced the lowest intracast pressures, even compared to backslabs (P = 0.009). Complete fiberglass casts generated the highest pain levels at manometer pressures of 75 mmHg and greater (P = 0.001). Split fiberglass casts had significantly reduced pain

  17. Differences Between Right and Left Arm Blood Pressures in the Elderly

    OpenAIRE

    Hashimoto, Fred; Hunt, William C.; Hardy, Linda

    1984-01-01

    Recommendations vary on whether blood pressures should be measured in the right or in the left arm because no frequency distributions for a pressure difference between the arms exist. We took a total of 12 blood pressure determinations in both arms of 174 elderly persons and analyzed the data by a least-squares components of variance method. The mean difference between the arms (right minus left) was 0.93 mm of mercury for systole and 0.70 mm of mercury for diastole. For systole the proportio...

  18. 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...... the correct direction of the phase envelope shift. Combined with the multicomponent Clapeyron equation, the equations reveal why the shift changes direction for the saturation pressure at the cricondentherm and for the saturation temperature at the cricondenbar. The equations can be used to estimate...

  19. 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.

  20. Empirical Formulas for Calculation of Negative Pressure Difference in Vacuum Pipelines

    Directory of Open Access Journals (Sweden)

    Marek Kalenik

    2015-10-01

    Full Text Available The paper presents the analysis of results of empirical investigations of a negative pressure difference in vacuum pipelines with internal diameters of 57, 81, 102 mm. The investigations were performed in an experimental installation of a vacuum sewage system, built in a laboratory hall on a scale of 1:1. The paper contains a review of the literature concerning two-phase flows (liquid-gas in horizontal, vertical and diagonal pipelines. It presents the construction and working principles of the experimental installation of vacuum sewage system in steady and unsteady conditions during a two-phase flow of water and air. It also presents a methodology for determination of formula for calculation of a negative pressure difference in vacuum pipelines. The results obtained from the measurements of the negative pressure difference Δpvr in the vacuum pipelines were analyzed and compared with the results of calculations of the negative pressure difference Δpvr, obtained from the determined formula. The values of the negative pressure difference Δpvr calculated for the vacuum pipelines with internal diameters of 57, 81, and 102 mm with the use of Formula (19 coincide with the values of Δpvr measured in the experimental installation of a vacuum sewage system. The dependence of the negative pressure difference Δpvr along the length of the vacuum pipelines on the set negative pressure in the vacuum container pvzp is linear. The smaller the vacuum pipeline diameter, the greater the negative pressure difference Δpvr is along its length.

  1. Electrical explosion of Al and Ag wires in air at different pressures

    Science.gov (United States)

    Sarkisov, G. S.; Caplinger, J.; Parada, F.; Sotnikov, V. I.

    2016-09-01

    Experiments with electrically exploding fine Al and Ag wires in air demonstrate a strong dependence of the expanding metal core condition and velocity on ambient pressure. Expansion velocity of the wire core varies by 23 times between ˜0.2 km/s and ˜4.6 km/s. The shock-wave velocity at atmospheric pressure is ˜5 km/s and increases to ˜6 km/s when the pressure is decreased to 50 Torr. The condition of the metal core is strongly dependent on material and whether it is expanding into vacuum or against ambient air pressure. Expansion velocity of the fine Al and Ag wires for different surrounding pressures in general agree with Paschen's Law for air gap.

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

    Directory of Open Access Journals (Sweden)

    Nima Jamshidi

    2010-01-01

    Full Text Available 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 tra-jectory 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 tri-als (+2 to collect the center of pressure using a force plate. Center of pressure patterns were categorized into four pat-terns 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.

  3. Differences in Centre of Pressure Trajectory between Normal and Steppage Gait

    Directory of Open Access Journals (Sweden)

    Nima Jamshidi

    2010-01-01

    Full Text Available Abstract Background: This pilot study aimed to assess the differences in centre of pressure trajectory in neuropathic patients with steppage gait. Steppage gait was previously evaluated by several biomechanical methods, but plantar pressure distribution has been much less studied. Our purpose was to analyze the changes in centre 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 at a mean of ten trials (+2 to collect the centre of pressure using a force plate. Centre of pressure patterns were categorized into four patterns based on the centre 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 result of this research indicated that the horizontal angle measured from centre of pressure linear regression in control group is positive (4.6± 2.4 (p<0.005 but in patients group is negative (-2.3±1.6 (p<0.005. Conclusions: The finding of this research measured centre 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.

  4. Mechanisms Of Pressure Distributions Within Laminar Separation Bubble At Different Reynolds Numbers

    Science.gov (United States)

    Lee, Donghwi; Kawai, Soshi; Nonomura, Taku; Oyama, Akira; Fujii, Kozo

    2014-11-01

    Large-eddy simulation around 5 % thickness flat plate at Re = 5 , 000 , 6 , 100 , 11 , 000 and 20 , 000 are performed and the physical mechanisms of the pressure distributions (Cp) in laminar separation bubbles are analyzed. Depending on the Reynolds number, a gradual pressure recovery and plateau pressure distribution are observed as experiments by Anyoji et al. [AIAA paper 2011-0852]. The causes of the pressure distributions are quantitatively shown by deriving the pressure gradient (momentum budget) equation from the steady momentum equation. From the results, we identify that the viscous diffusion term near the surface has a major contribution to the pressure gradients, and a different growth of the separated shear layer relying on the Reynolds numbers affects the viscous stress near the surface. The gradual pressure recovery at the lower Reynolds numbers is caused by the progressive development of separated shear layer due to the viscous stress which makes a non-negligible viscous stress. On the other hand, a thin laminar separated shear layer is created at the higher Reynolds numbers because of the relatively small viscous diffusion effects, which results in a negligible shear stress distribution. It makes dp / dx ~ 0 and the plateau pressure distribution is generated. Asahi Glass Scholarship.

  5. 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

  6. Effect of high-pressure homogenization on different matrices of food supplements.

    Science.gov (United States)

    Martínez-Sánchez, Ascensión; Tarazona-Díaz, Martha Patricia; García-González, Antonio; Gómez, Perla A; Aguayo, Encarna

    2016-12-01

    There is a growing demand for food supplements containing high amounts of vitamins, phenolic compounds and mineral content that provide health benefits. Those functional compounds have different solubility properties, and the maintenance of their compounds and the guarantee of their homogenic properties need the application of novel technologies. The quality of different drinkable functional foods after thermal processing (0.1 MPa) or high-pressure homogenization under two different conditions (80 MPa, 33 ℃ and 120 MPa, 43 ℃) was studied. Physicochemical characteristics and sensory qualities were evaluated throughout the six months of accelerated storage at 40 ℃ and 75% relative humidity (RH). Aroma and color were better maintained in high-pressure homogenization-treated samples than the thermally treated ones, which contributed significantly to extending their shelf life. The small particle size obtained after high-pressure homogenization treatments caused differences in turbidity and viscosity with respect to heat-treated samples. The use of high-pressure homogenization, more specifically, 120 MPa, provided active ingredient homogeneity to ensure uniform content in functional food supplements. Although the effect of high-pressure homogenization can be affected by the food matrix, high-pressure homogenization can be implemented as an alternative to conventional heat treatments in a commercial setting within the functional food supplement or pharmaceutical industry.

  7. Ocular Perfusion Pressure vs Estimated Trans-Lamina Cribrosa Pressure Difference in Glaucoma: The Central India Eye and Medical Study (An American Ophthalmological Society Thesis).

    Science.gov (United States)

    Jonas, Jost B; Wang, Ningli; Nangia, Vinay

    2015-01-01

    To test the hypothesis that taking translamina pressure difference into consideration changes associations between ocular perfusion pressure and glaucomatous optic neuropathy. The population-based Central India Eye and Medical Study included 4711 subjects. Ocular perfusion pressure was calculated as follows: ⅔ [diastolic blood pressure + ⅓ × (systolic blood pressure - diastolic blood pressure)] - IOP. Cerebrospinal fluid pressure (mm Hg) was estimated as follows: 0.44 body mass index (kg/m(2)) + 0.16 diastolic blood pressure (mm Hg) - 0.18 × age (years) - 1.91. Translamina pressure difference was IOP minus cerebrospinal fluid pressure. In multivariate analysis, higher open-angle glaucoma prevalence was associaed with higher IOP (P<.001; odds ratio [OR], 1.19; 95% CI, 1.15, 1.24) or with higher translamina pressure difference (P<.001; OR, 1.15; 95% CI, 1.10, 1.19), but not with ocular perfusion pressure (P<.37). A smaller neuroretinal rim area was correlated with higher IOP (P<.001; standardized coefficient beta -0.09) or larger translamina pressure difference (P<.001; β -0.10), but not with ocular perfusion pressure (P=.26). Greater prevalence of angle-closure glaucoma was associated with higher IOP (P<.001; OR, 1.22; 95% CI, 1.15, 1.28) or higher translamina pressure difference (P<.001; OR, 1.19; 95% CI, 1.13, 1.25) or lower ocular perfusion pressure (P<.04; OR, 0.95; 95% CI, 0.90, 0.996). Correlation coefficients were highest for the association with IOP and lowest for ocular perfusion pressure. A smaller rim area was correlated with higher IOP (P<.001; beta -0.08) and higher translamina pressure difference (P<.001; beta -0.08); rim area and ocular perfusion pressure were not significantly associated (P=.25). The present study provides information on the relationship of translamina pressure difference to the development of optic nerve damage in what is presently called glaucoma. It does not provide support of the idea that ocular perfusion pressure plays a

  8. 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.

  9. Stability characteristics of ring-stiffened cylindrical shells under different longitudinal and transverse external pressures

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Tian; YAO Wen; LIANG Chao; JI Nan

    2007-01-01

    Because ring-stiffened cylindrical shell structures have many merits, they are widely used in many areas. However, as the strength of steel increase continuously, ensuring of the structure stability is becoming more and more important. Therefore, it is necessary to carry on a more particular analysis. Based on the understanding and analysis of the characteristics of stability for a ring-stiffened cylindrical shell under uniform external pressure and under external single pressure, the characteristics under different cross uniform external pressures are analyzed, and the regularity of it is also gotten. The curve of stability given various geometrical parameters under different cross uniform external pressures is protracted by the analysis of the theory. The conclusion not only improves the theory structural mechanics, it also was important effects on engineering calculation and design.

  10. Research for different crack width calculation methods of concrete-lined steel pressure pipe

    Science.gov (United States)

    Xu, Chuang; Li, Yang

    2017-08-01

    Based on a certain threshold to ensure the durability of structure, the concrete-lined steel pressure pipes used in the structure of large hydropower station widely are allowed to exist in concrete cracking under the action of a certain hydraulic pressure. According to the 1:2 large scale experiment model and the measured data of Three Gorges Hydro-power Station, the existing different methods for calculating crack width were compared and improvements and crack control measures were raised.

  11. Racial differences in barriers to blood pressure control in a family practice setting.

    Science.gov (United States)

    Scott, Jonathan M; Spees, Colleen K; Taylor, Christopher A; Wexler, Randy

    2010-10-01

    Hypertension prevalence in the African American community is greater than in all other ethnic groups. Cultural perceptions of health and disease introduce barriers to providing effective care. The purpose of this study was to identify racial differences in the perceived causes of hypertension, current behaviors performed to control blood pressure, and perceived barriers to preventing or treating hypertension. A self-administered survey of patients seen for medical care in a primary care network was conducted. The survey was developed to measure perceptions of hypertension etiology and treatments. Data from African American (n = 69) and Caucasian (n = 218) respondents were used to assess racial differences in perceptions of blood pressure control. About half of respondents knew their current blood pressures. African American patients were significantly less likely to believe that hypertension was caused by a lack of exercise and obesity. Significantly more Caucasians were less likely to report cutting down on table salt and taking prescription medications for blood pressure control. Both African Americans and Caucasians believed that sodium reduction was the most easily changed behavior to control their blood pressure, while both groups identified weight loss as being the most difficult. Racial differences exist in the perceived causes and treatments of high blood pressure, indicating a need for further patient education. When treating and counseling patients, physicians and support staff members must be sensitive to racial diversity and strive to offer culturally relevant solutions, especially for behaviors perceived as most difficult to change.

  12. 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.

  13. The effect of three different toe props on plantar pressure and patient comfort

    Directory of Open Access Journals (Sweden)

    Johnson Sarah

    2012-08-01

    Full Text Available Abstract Background Arthritic toe pathologies frequently lead to the development of painful apical pressure skin lesions that can compromise gait and affect quality of life. Historically conservative treatments involve the use of a toe prop with the intended aim of reducing plantar pressure from the apex of the digit. However, the effect of toe prop treatment on plantar digital pressure has not been investigated. Method Twenty two subjects were recruited with lesser digital deformities and associated apical skin lesions. Individual pressure sensors were placed on the apices of the lesser toes and pressure was recorded under three toe prop conditions (leather, gel and silicone mould. A modified comfort index was utilised to assess the comfort of each condition. Results Significant difference (p nd toe when using the gel (p p nd toe when using gel (p p  Conclusion As compared to the leather and silicone mould toe props, gel toe props were found to be the most effective for reducing peak pressure and pressure time integral on the apex of the second digit in patients with claw or hammer toe deformity.

  14. Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass.

    Science.gov (United States)

    Tessutti, Vitor; Ribeiro, Ana Paula; Trombini-Souza, Francis; Sacco, Isabel C N

    2012-01-01

    The practice of running has consistently increased worldwide, and with it, related lower limb injuries. The type of running surface has been associated with running injury etiology, in addition other factors, such as the relationship between the amount and intensity of training. There is still controversy in the literature regarding the biomechanical effects of different types of running surfaces on foot-floor interaction. The aim of this study was to investigate the influence of running on asphalt, concrete, natural grass, and rubber on in-shoe pressure patterns in adult recreational runners. Forty-seven adult recreational runners ran twice for 40 m on all four different surfaces at 12 ± 5% km · h(-1). Peak pressure, pressure-time integral, and contact time were recorded by Pedar X insoles. Asphalt and concrete were similar for all plantar variables and pressure zones. Running on grass produced peak pressures 9.3% to 16.6% lower (P rubber was greater than on concrete for the rearfoot and midfoot. The behaviour of rubber was similar to that obtained for the rigid surfaces - concrete and asphalt - possibly because of its time of usage (five years). Running on natural grass attenuates in-shoe plantar pressures in recreational runners. If a runner controls the amount and intensity of practice, running on grass may reduce the total stress on the musculoskeletal system compared with the total musculoskeletal stress when running on more rigid surfaces, such as asphalt and concrete.

  15. A comparative sudy of two pressure relieving techniques on three different wheelchair cushions

    Directory of Open Access Journals (Sweden)

    C. Eksteen

    2006-02-01

    Full Text Available Introduction: Pressure relief done by a spinal cordinjured patient is of utmost importance in order to prevent pressuresore formation. Some pressure-relieving techniques are describedin previous literature, but their effectivity has not yet been deter-mined on different wheelchair cushions.Null Hypothesis (H0: The null hypothesis (H0 stated for thistudy is that there is no difference in the effectivity of forwardleaning and forward leaning towards the left as pressure relievingtechniques for quadriplegic wheelchair users over the differenwheelchair cushions.Design: An analytical experimental study design using a convenient sample group of ten complete lesion quadriplegics (C6 to T1 was performed at the Physiotherapy Department,University of Pretoria.Method: Interface pressure (in mmHg over the ischial tuberosities and upper thigh areas was measured using theTalley Oxford Pressure Monitor MKII with a 12-way matrix cell system.Results and Conclusion: The Friedman test for associated observations indicated statistically that the leaning  diagonally forward pressure relieving technique is more effective for all three wheelchair cushions used in this study.

  16. 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

  17. THE HABITABLE ZONE OF EARTH-LIKE PLANETS WITH DIFFERENT LEVELS OF ATMOSPHERIC PRESSURE

    Energy Technology Data Exchange (ETDEWEB)

    Vladilo, Giovanni; Murante, Giuseppe; Silva, Laura [INAF-Trieste Astronomical Observatory, Trieste (Italy); Provenzale, Antonello [Institute of Atmospheric Sciences and Climate-CNR, Torino (Italy); Ferri, Gaia; Ragazzini, Gregorio, E-mail: vladilo@oats.inaf.it [Department of Physics, University of Trieste, Trieste (Italy)

    2013-04-10

    As a contribution to the study of the habitability of extrasolar planets, we implemented a one-dimensional energy balance model (EBM), the simplest seasonal model of planetary climate, with new prescriptions for most physical quantities. Here we apply our EBM to investigate the surface habitability of planets with an Earth-like atmospheric composition but different levels of surface pressure. The habitability, defined as the mean fraction of the planet's surface on which liquid water could exist, is estimated from the pressure-dependent liquid water temperature range, taking into account seasonal and latitudinal variations of surface temperature. By running several thousands of EBM simulations we generated a map of the habitable zone (HZ) in the plane of the orbital semi-major axis, a, and surface pressure, p, for planets in circular orbits around a Sun-like star. As pressure increases, the HZ becomes broader, with an increase of 0.25 AU in its radial extent from p = 1/3 to 3 bar. At low pressure, the habitability is low and varies with a; at high pressure, the habitability is high and relatively constant inside the HZ. We interpret these results in terms of the pressure dependence of the greenhouse effect, the efficiency of horizontal heat transport, and the extent of the liquid water temperature range. Within the limits discussed in the paper, the results can be extended to planets in eccentric orbits around non-solar-type stars. The main characteristics of the pressure-dependent HZ are modestly affected by variations of planetary properties, particularly at high pressure.

  18. The Effect of Different Foot Orthosis Inverted Angles on Plantar Pressure in Children with Flexible Flatfeet.

    Directory of Open Access Journals (Sweden)

    Soo-Kyung Bok

    Full Text Available Although orthotic modification using the inverted technique is available for the treatment of flatfoot, empirical evidence for the biomechanical effects of inverted-angle foot orthoses (FOs is lacking. The aim of this study was to evaluate the effects of different FO inversion angles on plantar pressure during gait in children with flatfoot. Twenty-one children with flexible flatfeet (mean age 9.9 years were enrolled in this study. The plantar pressures were measured for the rearfoot; medial and lateral midfoot; and medial, central, and lateral forefoot as participants walked on a treadmill while wearing shoes only and shoes with the following 3 orthotic conditions: (i orthosis with no inverted angle, (ii orthosis with a 15° inverted angle, and (iii orthosis with a 30° inverted angle. A one-way repeated measures analysis of variance (ANOVA with the Bonferroni-adjusted post-hoc test was used to compare the mean values of each orthotic condition. Compared with the shoe only condition, the peak pressure decreased significantly under the medial forefoot and rearfoot with all FOs (p <0.05. However, no significant differences in the peak pressure under the medial forefoot and rearfoot were observed between the FOs. The peak pressure under the medial midfoot increased significantly with all FOs, and a maximal increase in the peak pressure was obtained with a 30° inverted angle orthosis. Furthermore, the contact area under the medial midfoot and rearfoot increased significantly with all FOs, compared with the shoe only condition (p <0.05. Again, no significant differences were observed between the FOs. For plantar pressure redistribution, a FO with a low inverted angle could be effective, accommodative, and convenient for children with flatfoot.

  19. Novel Insights on Hantavirus Evolution: The Dichotomy in Evolutionary Pressures Acting on Different Hantavirus Segments.

    Directory of Open Access Journals (Sweden)

    Sathish Sankar

    Full Text Available Hantaviruses are important emerging zoonotic pathogens. The current understanding of hantavirus evolution is complicated by the lack of consensus on co-divergence of hantaviruses with their animal hosts. In addition, hantaviruses have long-term associations with their reservoir hosts. Analyzing the relative abundance of dinucleotides may shed new light on hantavirus evolution. We studied the relative abundance of dinucleotides and the evolutionary pressures shaping different hantavirus segments.A total of 118 sequences were analyzed; this includes 51 sequences of the S segment, 43 sequences of the M segment and 23 sequences of the L segment. The relative abundance of dinucleotides, effective codon number (ENC, codon usage biases were analyzed. Standard methods were used to investigate the relative roles of mutational pressure and translational selection on the three hantavirus segments.All three segments of hantaviruses are CpG depleted. Mutational pressure is the predominant evolutionary force leading to CpG depletion among hantaviruses. Interestingly, the S segment of hantaviruses is GpU depleted and in contrast to CpG depletion, the depletion of GpU dinucleotides from the S segment is driven by translational selection. Our findings also suggest that mutational pressure is the primary evolutionary pressure acting on the S and the M segments of hantaviruses. While translational selection plays a key role in shaping the evolution of the L segment. Our findings highlight how different evolutionary pressures may contribute disproportionally to the evolution of the three hantavirus segments. These findings provide new insights on the current understanding of hantavirus evolution.There is a dichotomy among evolutionary pressures shaping a the relative abundance of different dinucleotides in hantavirus genomes b the evolution of the three hantavirus segments.

  20. Novel Insights on Hantavirus Evolution: The Dichotomy in Evolutionary Pressures Acting on Different Hantavirus Segments.

    Science.gov (United States)

    Sankar, Sathish; Upadhyay, Mohita; Ramamurthy, Mageshbabu; Vadivel, Kumaran; Sagadevan, Kalaiselvan; Nandagopal, Balaji; Vivekanandan, Perumal; Sridharan, Gopalan

    2015-01-01

    Hantaviruses are important emerging zoonotic pathogens. The current understanding of hantavirus evolution is complicated by the lack of consensus on co-divergence of hantaviruses with their animal hosts. In addition, hantaviruses have long-term associations with their reservoir hosts. Analyzing the relative abundance of dinucleotides may shed new light on hantavirus evolution. We studied the relative abundance of dinucleotides and the evolutionary pressures shaping different hantavirus segments. A total of 118 sequences were analyzed; this includes 51 sequences of the S segment, 43 sequences of the M segment and 23 sequences of the L segment. The relative abundance of dinucleotides, effective codon number (ENC), codon usage biases were analyzed. Standard methods were used to investigate the relative roles of mutational pressure and translational selection on the three hantavirus segments. All three segments of hantaviruses are CpG depleted. Mutational pressure is the predominant evolutionary force leading to CpG depletion among hantaviruses. Interestingly, the S segment of hantaviruses is GpU depleted and in contrast to CpG depletion, the depletion of GpU dinucleotides from the S segment is driven by translational selection. Our findings also suggest that mutational pressure is the primary evolutionary pressure acting on the S and the M segments of hantaviruses. While translational selection plays a key role in shaping the evolution of the L segment. Our findings highlight how different evolutionary pressures may contribute disproportionally to the evolution of the three hantavirus segments. These findings provide new insights on the current understanding of hantavirus evolution. There is a dichotomy among evolutionary pressures shaping a) the relative abundance of different dinucleotides in hantavirus genomes b) the evolution of the three hantavirus segments.

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

    Directory of Open Access Journals (Sweden)

    Alison O. Silva

    2016-04-01

    Full Text Available Abstract Objective: To assess the association between general and abdominal obesity with high blood pressure in adolescents of both genders from the public school system. Methods: 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. Results: The prevalence of high blood pressure was 6.4%, and it was higher among boys (9.0% vs. 4.7%, p < 0.05. There was no significant difference between general (p = 0.903 and abdominal obesity (p = 0.157 when genders were compared. After adjusting for age, high blood pressure was associated with general (OR = 6.4; p < 0.001 and abdominal obesity (OR = 7.0; p < 0.001 only among boys, when comparing the fourth quartile with the first quartile of body mass index (≤18.6 kg/m2 vs. ≥23.5 kg/m2 and waist circumference (≤69 cm vs. ≥80.1 cm. Conclusion: It was observed that general and abdominal obesity are associated with high blood pressure only in boys, regardless of age.

  2. Ethnic Differences in Physical Fitness, Blood Pressure and Blood Chemistry in Women (AGES 20-63)

    Science.gov (United States)

    Ayers, G. W.; Wier, L. T.; Jackson, A. S.; Stuteville, J. E.; Keptra, Sean (Technical Monitor)

    1999-01-01

    This study examined the role of ethnicity on the aerobic fitness, blood pressure, and selected blood chemistry values of women. One hundred twenty-four females (mean age 41.37 +/- 9.0) were medically Examined at the NASA/Johnson Space Center occupational health clinic. Ethnic groups consisted of 23 Black (B), 18 Hispanic (H) and 83 Non-minority (NM). Each woman had a maximum Bruce treadmill stress test (RER greater than or = 1.1) and a negative ECG. Indirect calorimetry, skinfolds, self-report physical activity (NASA activity scale), seated blood pressure, and blood chemistry panel determined VO2max, percent fat, level of physical activity, blood pressure and blood chemistry values. ANOVA revealed that the groups did not differ (p greater than 0.05) in age, VO2 max, weight, percent fat, level of physical activity, total cholesterol, or HDL-C. However, significant differences (p greater than 0.05) were noted in BMI, diastolic blood pressure, and blood chemistries. BMI was 3.17 higher in H than in NM; resting diastolic pressures were 5.69 and 8.05 mmHg. lower in NM and H than in B; triglycerides were 48.07 and 37.21 mg/dl higher in H than in B and NM; hemoglobin was .814 gm/dl higher in NM than B; fasting blood sugar was 15.41 mg/dl higher in H than NM; The results of this study showed that ethnic groups differed in blood pressure and blood chemistry values but not aerobic fitness or physical activity. There was an ethnic difference in BMI but not percent fat.

  3. Ethnic Differences in Physical Fitness, Blood Pressure and Blood Chemistry in Women (AGES 20-63)

    Science.gov (United States)

    Ayers, G. W.; Wier, L. T.; Jackson, A. S.; Stuteville, J. E.; Keptra, Sean (Technical Monitor)

    1999-01-01

    This study examined the role of ethnicity on the aerobic fitness, blood pressure, and selected blood chemistry values of women. One hundred twenty-four females (mean age 41.37 +/- 9.0) were medically Examined at the NASA/Johnson Space Center occupational health clinic. Ethnic groups consisted of 23 Black (B), 18 Hispanic (H) and 83 Non-minority (NM). Each woman had a maximum Bruce treadmill stress test (RER greater than or = 1.1) and a negative ECG. Indirect calorimetry, skinfolds, self-report physical activity (NASA activity scale), seated blood pressure, and blood chemistry panel determined VO2max, percent fat, level of physical activity, blood pressure and blood chemistry values. ANOVA revealed that the groups did not differ (p greater than 0.05) in age, VO2 max, weight, percent fat, level of physical activity, total cholesterol, or HDL-C. However, significant differences (p greater than 0.05) were noted in BMI, diastolic blood pressure, and blood chemistries. BMI was 3.17 higher in H than in NM; resting diastolic pressures were 5.69 and 8.05 mmHg. lower in NM and H than in B; triglycerides were 48.07 and 37.21 mg/dl higher in H than in B and NM; hemoglobin was .814 gm/dl higher in NM than B; fasting blood sugar was 15.41 mg/dl higher in H than NM; The results of this study showed that ethnic groups differed in blood pressure and blood chemistry values but not aerobic fitness or physical activity. There was an ethnic difference in BMI but not percent fat.

  4. Experimental Investigation of Seepage Properties of Fractured Rocks Under Different Confining Pressures

    Science.gov (United States)

    Ma, D.; Miao, X. X.; Chen, Z. Q.; Mao, X. B.

    2013-09-01

    The effectiveness of transmitting underground water in rock fractures is strongly influenced by the widths of the fractures and their interconnections. However, the geometries needed for water flow in fractured rock are also heavily controlled by the confining pressure conditions. This paper is intended to study the seepage properties of fractured rocks under different confining pressures. In order to do this, we designed and manufactured a water flow apparatus that can be connected to the electro-hydraulic servo-controlled test system MTS815.02, which provides loading and exhibits external pressures in the test. Using this apparatus, we tested fractured mudstone, limestone and sandstone specimens and obtained the relationship between seepage properties and variations in confining pressure. The calculation of the seepage properties based on the collection of water flow and confining pressure differences is specifically influenced by non-Darcy flow. The results show that: (1) The seepage properties of fractured rocks are related to confining pressure, i.e. with the increase of confining pressure, the permeability decreases and the absolute value of non-Darcy flow coefficient increases. (2) The sandstone coefficients and range from to m2 and to m-1, respectively, and exhibit a greater change compared to coefficients of mudstone and limestone. (3) From the regression analysis of experimental data, it is concluded that the polynomial function is a better fit than the power and logarithmic functions. The results obtained can provide an important reference for understanding the stability of rock surrounding roadways toward prevention of underground water gushing-out, and for developing underground resources (e.g. coal).

  5. Ignition and combustion characteristics of molded amorphous boron under different oxygen pressures

    Science.gov (United States)

    Liang, Daolun; Liu, Jianzhong; Zhou, Yunan; Zhou, Junhu; Cen, Kefa

    2017-09-01

    Ignition and combustion characteristics of amorphous boron (B) have received much attention from researchers in recent decades. A pressurized concentrated ignition experimental system was designed to evaluate the ignition and combustion characteristics of molded B samples. The ignition experiments were carried out under different oxygen pressures (1-9 atm). The condensed combustion products were then analyzed using a scanning electron microscope, an X-ray energy dispersive spectrometer, and an X-ray diffractometer. Furthermore, the complete oxidation rates of the samples were detected by inductively coupled plasma chromatography. As the oxygen pressure increased, the combustion intensity of the samples steadily increased, and the ignition delay time and combustion time both decreased. Under the oxygen pressure of 9 atm, the average ignition delay time and combustion time were 2640 ms and 2596 ms, respectively, and the highest combustion temperature reached 1561.5 °C. The initial diffusion flame on the sample surface was green and the brightest, which was produced by an intermediate combustion product, BO2 (corresponding molecular emission spectrum wavelength, 547.3 nm). Emission spectra of another intermediate product, BO (431.9 nm) was also detected. Two different types of structures were found in the condensed combustion products of the samples. The first type was the flaky B2O3 structure, and the second type was the flocculent structure of incomplete combustion products. The B2O3 content in the condensed combustion products increased with the oxygen pressure during combustion. The complete oxidation ratio of the samples also increased with the oxygen pressure, and reached the maximum value of 68.71% under 9 atm. Overall, the samples showed better ignition and combustion characteristics under higher oxygen pressure.

  6. 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.

  7. Different selective pressures lead to different genomic outcomes as newly-formed hybrid yeasts evolve

    Science.gov (United States)

    2012-01-01

    Background Interspecific hybridization occurs in every eukaryotic kingdom. While hybrid progeny are frequently at a selective disadvantage, in some instances their increased genome size and complexity may result in greater stress resistance than their ancestors, which can be adaptively advantageous at the edges of their ancestors' ranges. While this phenomenon has been repeatedly documented in the field, the response of hybrid populations to long-term selection has not often been explored in the lab. To fill this knowledge gap we crossed the two most distantly related members of the Saccharomyces sensu stricto group, S. cerevisiae and S. uvarum, and established a mixed population of homoploid and aneuploid hybrids to study how different types of selection impact hybrid genome structure. Results As temperature was raised incrementally from 31°C to 46.5°C over 500 generations of continuous culture, selection favored loss of the S. uvarum genome, although the kinetics of genome loss differed among independent replicates. Temperature-selected isolates exhibited greater inherent and induced thermal tolerance than parental species and founding hybrids, and also exhibited ethanol resistance. In contrast, as exogenous ethanol was increased from 0% to 14% over 500 generations of continuous culture, selection favored euploid S. cerevisiae x S. uvarum hybrids. Ethanol-selected isolates were more ethanol tolerant than S. uvarum and one of the founding hybrids, but did not exhibit resistance to temperature stress. Relative to parental and founding hybrids, temperature-selected strains showed heritable differences in cell wall structure in the forms of increased resistance to zymolyase digestion and Micafungin, which targets cell wall biosynthesis. Conclusions This is the first study to show experimentally that the genomic fate of newly-formed interspecific hybrids depends on the type of selection they encounter during the course of evolution, underscoring the importance of

  8. Different selective pressures lead to different genomic outcomes as newly-formed hybrid yeasts evolve

    Directory of Open Access Journals (Sweden)

    Piotrowski Jeff S

    2012-04-01

    Full Text Available Abstract Background Interspecific hybridization occurs in every eukaryotic kingdom. While hybrid progeny are frequently at a selective disadvantage, in some instances their increased genome size and complexity may result in greater stress resistance than their ancestors, which can be adaptively advantageous at the edges of their ancestors' ranges. While this phenomenon has been repeatedly documented in the field, the response of hybrid populations to long-term selection has not often been explored in the lab. To fill this knowledge gap we crossed the two most distantly related members of the Saccharomyces sensu stricto group, S. cerevisiae and S. uvarum, and established a mixed population of homoploid and aneuploid hybrids to study how different types of selection impact hybrid genome structure. Results As temperature was raised incrementally from 31°C to 46.5°C over 500 generations of continuous culture, selection favored loss of the S. uvarum genome, although the kinetics of genome loss differed among independent replicates. Temperature-selected isolates exhibited greater inherent and induced thermal tolerance than parental species and founding hybrids, and also exhibited ethanol resistance. In contrast, as exogenous ethanol was increased from 0% to 14% over 500 generations of continuous culture, selection favored euploid S. cerevisiae x S. uvarum hybrids. Ethanol-selected isolates were more ethanol tolerant than S. uvarum and one of the founding hybrids, but did not exhibit resistance to temperature stress. Relative to parental and founding hybrids, temperature-selected strains showed heritable differences in cell wall structure in the forms of increased resistance to zymolyase digestion and Micafungin, which targets cell wall biosynthesis. Conclusions This is the first study to show experimentally that the genomic fate of newly-formed interspecific hybrids depends on the type of selection they encounter during the course of evolution

  9. 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 ...

  10. EFFECT OF GENDER DIFFERENCE AND CIRCADIAN RHYTHM ON DIASTOLIC BLOOD PRESSURE FOR VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    I. Rajagopal

    2011-04-01

    Full Text Available The purpose of the study was to find out the effect of gender difference and circadian rhythm on diastolic blood pressure for volleyball players. METHODS: To achieve the purpose, a total of thirty volleyball players [men (n = 15 and women (n = 15] age between 19 years and 22 years from Einstein College of Engineering, Tamil Nadu, India were selected as subjects. The two independent variables of gender and circadian variations and dependent variable of diastolic blood pressure were selected for this study. The experimental design used was static group factorial design. The data were collected at 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 hours on diastolic blood pressure by using Erkameter during the academic year of 2009 – 2010. Collected data were subjected to statistical analysis by using two-way factorial (2 x 6 Analysis of Variance (ANOVA and Cosinor analysis. RESULTS: There was insignificant difference between genders, significant difference at different times of the day and insignificant circadian rhythmicity exists on diastolic blood pressure for women and significant for men. CONCLUSION: It is recommended to the physical educators to adopt the findings of this study while planning to improve sports skills for the players and athletes.

  11. 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.

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

    Science.gov (United States)

    Kim, Jung-Hoon; Seo, Chang-Seob; Kim, Seong-Sil; Shin, Hyeun-Kyoo

    2012-06-01

    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.

  13. [X-ray diffraction study of high hydrostatic pressure on crystalline structure of different type starches].

    Science.gov (United States)

    Liu, Pei-Ling; Shen, Qun; Hu, Xiao-Song; Wu, Ji-Hong

    2012-09-01

    Crystalline changes of different type starches after high hydrostatic pressure treated under 300, 450, 600 MPa were studied by X-ray diffraction. Waxy maize (A type, 100% amylopectin), hylon VII (B type, 30% amylopectin) and tapioca starch (C type, 83% amylopectin) were chosen. The results indicated that for waxy maize starch, annealing effect was observed at 300 MPa, disappearance of crystalline structure happened at 450 MPa and retrogradation at 600 MPa. The results proved that the granule under high hydrostatic pressure processing experiences "three development stages" including annealling effect, disappearance of crystalline structure and recrystalline after granule disintegration.

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

    OpenAIRE

    2012-01-01

    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; b...

  15. Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure.

    Science.gov (United States)

    Zheng, Dingchang; Murray, Alan

    2011-05-01

    A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s(-1) and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures.

  16. 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 (pperfusion (from 49.9±3.3 and 79.5±5.1 in baseline to a maximum of 114.4±13.9 and 211.7±70.5 (pperfusion mechanics 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.

  17. Tongue resting pressure of the tongue anchorage pad in different body positions: a pilot study.

    Science.gov (United States)

    Zeng, J; Xu, K; Gao, X; Xu, T

    2015-06-01

    We designed a modified transpalatal arch (tongue anchorage pad, TAP) to help control the vertical dimension. This study aimed to evaluate its efficiency by measuring the tongue resting pressure at different anteroposterior positions of the TAP in the upright and supine positions and to investigate the effect of changes in body position. Our study recruited 17 volunteers with individual normal occlusion (4 males, 13 females, age 22-33 years). An individualised TAP was designed for each subject. With a miniature sensor (FSS1500NS) installed in the device, we measured the pressure at the level of the distal second premolar (PM2), the first molar (M1) and the second molar (M2) in both the upright and supine positions. Nonparametric analysis was applied with the level of significance set at 0.05. In the upright position, tongue pressures obtained at PM2, M1 and M2 were 183.94, 130.81 and 113.07 Pa, respectively, with the maximum value detected at PM2 (P = 0.001). While in the supine position, pressures of 187.03, 156.87 and 201.69 Pa were detected at the same sites, with significantly higher values for M1 (P = 0.002) and M2 (P = 0.004). Tongue resting pressure decreases from the anterior aspect to the posterior aspect in the upright position. In the supine position, the pressure is consistent across the midline with pressure enhancement at M1 and M2. As many questions remain about this appliance and appropriate intruding force, further clinical and basic studies are required prior to its clinical implementation.

  18. 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.

  19. 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.

  20. Local order evolution of liquid Cu during glass transition under different pressures: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.D., E-mail: ydli@ustc.edu [School of Physics and Material Science, Anhui University, Hefei 230039 (China); Lu, Q.L. [School of Physics and Material Science, Anhui University, Hefei 230039 (China); Wang, C.C., E-mail: ccwang@ahu.edu.cn [School of Physics and Material Science, Anhui University, Hefei 230039 (China); Huang, S.G. [School of Physics and Material Science, Anhui University, Hefei 230039 (China); Liu, C.S. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China)

    2013-01-01

    Based on the second-moment approximation of tight-binding scheme, constant-pressure molecular dynamics simulations are performed for liquid Cu during the glass transition under different pressures. By means of pair analysis technique and bond orientational order analysis we find that the dominant bond pairs are those related to fcc and hcp crystalline order not those representing icosahedral short-range order (ISRO) when the systems enter into glass transition region. Although these two kinds of bond pairs compete with each other, the system tends towards a mixture of crystalline bond pairs during glass formation. The effect on various bond pairs brought about by higher pressure is much less for liquids than for glasses. The experimental observation of a shoulder on the second peak of the structure factor for supercooled liquids might not merely attribute to ISRO, since supercooled liquid Cu exhibits such a shoulder, but does not display an enhanced icosahedral symmetry.

  1. Dielectric Properties of Capacitive-Type Humidity Sensor Made under Different Pressures

    Institute of Scientific and Technical Information of China (English)

    Jing Wang; Xiao-hua Wang

    2006-01-01

    Capacitive humidity sensors were made of nanometer barium titanate. The pellets were prepared under different pressures between 3920N to 7850N force. The capacitance changes in three orders of magnitude in the relative humidity range of 10% ~ 98%, indicating high humidity sensitivity of the sensors. At a certain measuring frequency, the capacitance of the sensors increases as increasing of the preparation pressure, while the sensitivity of the sensors basically remains the same. The frequencies corresponding to the peaks of the dielectric loss of the sensors move to the higher frequency direction as increasing of the relative humidity. At a certain humidity, the frequencies corresponding to the peaks of the dielectric loss move to the higher frequency direction as increasing of the preparation pressure.

  2. The effects of blood pressure reduction and of different blood pressure-lowering regimens on major cardiovascular events according to baseline blood pressure : meta-analysis of randomized trials

    NARCIS (Netherlands)

    Czernichow, Sebastien; Zanchetti, Alberto; Turnbull, Fiona; Barzi, Federica; Ninomiya, Toshiaru; Kengne, Andre-Pascal; Lambers Heerspink, Hiddo J.; Perkovic, Vlado; Huxley, Rachel; Arima, Hisatomi; Patel, Anushka; Chalmers, John; Woodward, Mark; MacMahon, Stephen; Neal, Bruce

    2011-01-01

    Background The benefits of reducing blood pressure are well established, but there remains uncertainty about whether the magnitude of the effect varies with the initial blood pressure level. The objective was to compare the risk reductions achieved by different blood pressure-lowering regimens among

  3. The effects of blood pressure reduction and of different blood pressure-lowering regimens on major cardiovascular events according to baseline blood pressure : meta-analysis of randomized trials

    NARCIS (Netherlands)

    Czernichow, Sebastien; Zanchetti, Alberto; Turnbull, Fiona; Barzi, Federica; Ninomiya, Toshiaru; Kengne, Andre-Pascal; Lambers Heerspink, Hiddo J.; Perkovic, Vlado; Huxley, Rachel; Arima, Hisatomi; Patel, Anushka; Chalmers, John; Woodward, Mark; MacMahon, Stephen; Neal, Bruce

    Background The benefits of reducing blood pressure are well established, but there remains uncertainty about whether the magnitude of the effect varies with the initial blood pressure level. The objective was to compare the risk reductions achieved by different blood pressure-lowering regimens among

  4. The habitable zone of Earth-like planets with different levels of atmospheric pressure

    CERN Document Server

    Vladilo, Giovanni; Silva, Laura; Provenzale, Antonello; Ferri, Gaia; Ragazzini, Gregorio

    2013-01-01

    As a contribution to the study of the habitability of extrasolar planets, we implemented a 1-D Energy Balance Model (EBM), the simplest seasonal model of planetary climate, with new prescriptions for most physical quantities. Here we apply our EBM to investigate the surface habitability of planets with an Earth-like atmospheric composition but different levels of surface pressure. The habitability, defined as the mean fraction of the planet's surface on which liquid water could exist, is estimated from the pressure-dependent liquid water temperature range, taking into account seasonal and latitudinal variations of surface temperature. By running several thousands of EBM simulations we generated a map of the habitable zone (HZ) in the plane of the orbital semi-major axis, a, and surface pressure, p, for planets in circular orbits around a Sun-like star. As pressure increases, the HZ becomes broader, with an increase of 0.25 AU in its radial extent from p=1/3 bar to p=3 bar. At low pressure, the habitability is...

  5. Effect of annealing and pressure on microstructure of cornstarches with different amylose/amylopectin ratios.

    Science.gov (United States)

    Liu, Hongsheng; Yu, Long; Simon, George; Zhang, Xiaoqing; Dean, Katherine; Chen, Ling

    2009-02-17

    This work focuses on the effect of annealing and pressure on microstructures of starch, in particular the crystal structure and crystallinity to further explore the mechanisms of annealing and pressure treatment. Cornstarches with different amylose/amylopectin ratios were used as model materials. Since the samples covered both A-type (high amylopectin starch: waxy and maize) and B-type (high amylose starch: G50 and G80) crystals, the results can be used to clarify some previous confusion. The effect of annealing and pressure on the crystallinity and double helices were investigated by X-ray diffraction (XRD) and (13)C CP/MAS NMR spectroscopy. The crystal form of various starches remained unchanged after annealing and pressure treatment. XRD detection showed that the relative crystallinity (RC) of high amylopectin starches was increased slightly after annealing, while the RC of high amylose-rich starches remained unchanged. NMR measurement supported the XRD results. The increase can be explained by the chain relaxation. XRD results also indicated that some of the fixed region in crystallinity was susceptible to outside forces. The effect of annealing and pressure on starch gelatinization temperature and enthalpy are used to explore the mechanisms.

  6. Selection Pressure on Haemagglutinin Genes of H9N2 Influenza Viruses from Different Hosts

    Institute of Scientific and Technical Information of China (English)

    Wei-feng SHI; Ai-she DUN; Zhong ZHANG; Yan-zhou ZHANG; Guang-fu YU; Dong-ming ZHUANG; Chao-dong ZHU

    2009-01-01

    Positive selection and differential selective pressure analyses were carried out to study Haemagglutinin (HA) genes of H9N2 influenza viruses from different hosts in this paper. Results showed that, although most positions in HAs were under neutral or purifying evolution, a few positions located in the antigenic regions and receptor binding sites were subject to positive selection and some of them were even positively selected at the population level. In addition, there were always some positions differentially selected for viruses from different hosts. Both selection pressure working on HA codons and positions differentially selected might account for the extension of the host range and adaptations to different hosts of H9N2 influenza viruses.

  7. Effects of blood pressure-lowering treatment in different subtypes of acute ischemic stroke.

    Science.gov (United States)

    Sandset, Else Charlotte; Jusufovic, Mirza; Sandset, Per Morten; Bath, Philip M W; Berge, Eivind

    2015-03-01

    The Scandinavian Candesartan Acute Stroke Trial (SCAST) found no benefits of blood pressure-lowering treatment with candesartan in acute stroke. We have investigated whether the effect of treatment is different in different subtypes of ischemic stroke. SCAST was a randomized- and placebo-controlled trial of candesartan in 2029 patients presenting within 30 hours of ischemic or hemorrhagic stroke and systolic blood pressure ≥140 mm Hg. Ischemic stroke subtype was categorized by the Oxfordshire Community Stroke Project classification. There were 2 primary effect variables: the composite vascular end point of vascular death, myocardial infarction, or stroke during the first 6 months and functional outcome at 6 months. A total of 1733 patients with ischemic stroke were included: total anterior circulation infarcts in 129, partial anterior in 850, posterior in 236, and lacunar in 510 patients. For functional outcome there was a significant trend toward a better effect of candesartan in patients with larger infarcts (total anterior circulation or partial anterior circulation) than in patients with smaller infarcts (lacunar infarction; P=0.02). For the composite vascular end point, there were no differences in treatment effect. The results suggest that the effect of blood pressure-lowering treatment with candesartan may differ according to different types of acute ischemic stroke, but this needs to be confirmed in future trials. http://www.clinicaltrials.gov. Unique identifier: NCT00120003. © 2015 American Heart Association, Inc.

  8. BLOOD PRESSURE DIFFERENCES BY ETHNIC GROUP AMONG U.S. CHILDREN AND ADOLESCENTS

    Science.gov (United States)

    Rosner, Bernard; Cook, Nancy; Portman, Ron; Daniels, Steve; Falkner, Bonita

    2011-01-01

    Large differences in blood pressure by ethnic group are apparent among adults. There is uncertainty as to whether similar differences by ethnic group exist among children and if so, the age of onset. Blood pressure (BP) measurements were obtained from 58,698 children at 78,556 visits using data from the Pediatric Task Force data, a collection of 11 studies with BP data from children and adolescents age 1–17. Generalized estimating equation methods were used to identify sex-specific differences in body mass index (BMI)-adjusted rates of BP elevation and pre-hypertension by ethnic group. Significant BMI-adjusted differences in rates of BP elevation were found between Hispanic boys vs. Caucasian boys (OR = 1.21, 95% CI = 1.07–1.37, p=0.002). No overall significant differences were found between African-American (AA) boys vs. Caucasian (Cauc) boys (OR = 1.03, 95% CI = 0.95–1.12, p=0.49); however, there was significant effect modification (p = 0.01) with significant differences found for normal weight boys (BMI ethnic group differences in BMI-adjusted rates of hypertension were found for girls. Ethnic differences in prevalence rates of pediatric BP elevation that are not explained by obesity are present, primarily in boys. Whether these differences are due to genetic or environmental factors is unknown. PMID:19652080

  9. Structure and extreme ultraviolet performance of Si/C multilayers deposited under different working pressures.

    Science.gov (United States)

    Yi, Qiang; Huang, Qiushi; Wang, Xiangmei; Yang, Yang; Yang, Xiaowei; Zhang, Zhong; Wang, Zhanshan; Xu, Rongkun; Peng, Taiping; Zhou, Hongjun; Huo, Tonglin

    2017-02-01

    Narrow bandwidth Si/C multilayer mirrors are fabricated and characterized for the Z-pinch plasma diagnostic at a wavelength of 16.5 nm. To reduce the large stress of the multilayer and maintain a practical reflectivity, different working pressures, from 0.13 Pa to 0.52 Pa, are optimized during the deposition. The grazing incidence x-ray reflectometry (GIXR) measurement and the fitting results indicate that an interlayer was formed at the interfaces, while both the interlayer thickness and interface widths increase with larger working pressure. The surface roughness of the multilayers also increases from 0.13 nm at 0.13 Pa to 0.29 nm at 0.52 Pa, as revealed by the atomic force microscope (AFM) measurements. The multilayer stress decreases from -682 MPa to -384  MPa as the working pressure increases from 0.13 Pa to 0.52 Pa, respectively. The experimental extreme ultraviolet (EUV) reflectivity of the samples with 20 bilayers gradually decreased from 26.3% to 18.9% with increased working pressure. The bandwidth of the reflection peak remains similar for the different samples with a full width half-maximum (FWHM) value of around 0.87 nm. A maximum EUV reflectivity of 33.2% and a bandwidth of 0.64 nm were achieved by the sample with 50 bilayers fabricated under a working pressure of 0.13 Pa.

  10. Antihypertensive drug classes have different effects on short-term blood pressure variability in essential hypertension.

    Science.gov (United States)

    Levi-Marpillat, Natacha; Macquin-Mavier, Isabelle; Tropeano, Anne-Isabelle; Parati, Gianfranco; Maison, Patrick

    2014-06-01

    Increased blood pressure variability (BPV) contributes to end-organ damage, cardiovascular events and mortality associated with hypertension. In a cohort of 2780 hypertensive patients treated by either calcium channel blockers (CCBs), diuretics, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs) or β-blockers alone or in combination, we compared indices of short-term BPV according to the different treatments. Short-term BPV was calculated as the standard deviation (s.d.) of 24 h, daytime or nighttime systolic blood pressure and diastolic blood pressure (SBP and DBP). Short-term BPV was compared between patients treated with a given antihypertensive class of interest (alone or in combination) and those not treated with this class, after controlling for ambulatory average blood pressure, heart rate, age, gender, propensity scores and carotid-femoral pulse wave velocity. Patients treated with CCBs (n=1247) or diuretics (n=1486) alone, or in addition to other drugs had significant lower s.d. of 24-h SBP compared with those not treated with these classes (mean differences in s.d. -0.50±0.50 mm Hg, P=0.001 and -0.17±0.15 mm Hg, P=0.05, respectively). There was no significant difference regarding treatment with or without ARBs, ACEIs and β-blockers. The combinations of CCBs with diuretics or ARBs on top of other treatments resulted in a lower 24-h SBP variability (mean differences in s.d. -0.43±0.17 mm Hg, P=0.02 and -0.44±0.19 mm Hg, P=0.005 vs. other combination uses, respectively). Antihypertensive drug classes have differential effects on short-term BPV with a greater reduction in patients treated with CCBs and diuretics. The combinations of CCBs with diuretics may be the most efficient treatments in lowering BPV.

  11. Application and Comparison of Different Combustion Models of High Pressure LOX/CH4 Jet Flames

    OpenAIRE

    Maria Grazia De Giorgi; Aldebara Sciolti; Antonio Ficarella

    2014-01-01

    The present work focuses on the numerical modeling of combustion in liquid-propellant rocket engines. Pressure and temperature are well above thermodynamic critical points of both the propellants and then the reactants show liquid-like characteristics of density and gas-like characteristics for diffusivity. The aim of the work is an efficient numerical description of the phenomena and RANS simulations were performed for this purpose. Hence, in the present work different kinetics, combustion ...

  12. 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.

  13. Literature review and meta-analysis of translaminar pressure difference in open-angle glaucoma.

    Science.gov (United States)

    Siaudvytyte, L; Januleviciene, I; Daveckaite, A; Ragauskas, A; Bartusis, L; Kucinoviene, J; Siesky, B; Harris, A

    2015-10-01

    There is increasing evidence in the literature regarding translaminar pressure difference's (TPD) role in the pathophysiology of glaucoma. The optic nerve is exposed not only to intraocular pressure in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Although pilot studies have identified the potential importance of TPD in glaucoma, limited available data currently prevent a comprehensive description of the role that TPD may have in glaucomatous pathophysiology. In this review, we present all available qualified data from a systematic review of the literature of the role of TPD in open-angle glaucoma (OAG). PubMed (Medline), OVID Medline, ScienceDirect, SpringerLink, and all available library databases were reviewed and subsequent meta-analysis of pooled mean differences are presented where appropriate. Five papers including 396 patients met criteria for inclusion to the analysis. Importantly, we included all observational studies despite differences in ICP measurement methods, as there is no consensus regarding best-practice ICP measurements in glaucoma. Our results show that not only TPD is higher in glaucoma patients compared with healthy subjects, it is related to structural glaucomatous changes of the optic disc. Our analysis suggests further longitudinal prospective studies are needed to investigate the influence of TPD in OAG, with a goal of overcoming methodological weaknesses of previous studies.

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

    Institute of Scientific and Technical Information of China (English)

    Ai-Yun Shen

    2016-01-01

    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.

  15. ASSOCIATION OF BODY MASS INDEX WITH INTERARM BLOOD PRESSURE DIFFERENCE: A COMPARATIVE AND CROSS SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Namala Surya

    2015-11-01

    Full Text Available The major health problem faced by the 13% of world population is obesity and this obesity and overweight may lead to many health consequences such as cardiovascular diseases, diabetes and some cancers to mention a few. Objective of present study is to find the relation between the increased BMI and the interarm blood pressure difference. MATERIALS AND METHODS The present study was conducted on 180 subjects with age ranging from 18 to 50 years. They were divided into two groups based on the BMI. Subjects with normal BMI (25Kg/M2. The study was conducted in the GSL Medical College and General Hospital, Rajahmundry. RESULTS On comparing the results in overweight subjects in the age group of 40-50 were found to have interarm difference in the mean systolic blood pressure of more than 10mmHg, i.e. Mean value of 13.04+ 2.34(<0.001. CONCLUSION The overweight individuals with age more than 40 years, there is interarm difference in the mean systolic blood pressure, which is an indicator of peripheral vascular disease.

  16. Inactivation differences of microorganisms by low pressure UV and pulsed xenon lamps.

    Science.gov (United States)

    Otaki, M; Okuda, A; Tajima, K; Iwasaki, T; Kinoshita, S; Ohgaki, S

    2003-01-01

    UV disinfection has been applied to water treatment in recent years with low-pressure and medium-pressure UV lamps mainly used as the light source. In general, UV disinfection is considered to be inefficient with water of high turbidity because of inhibition of light penetration. Additionally, photoreactivation may be a problem that should be considered in case a disinfected water is discharged to the environment where sunlight causes reactivation. Recently, other types of lamps have been proposed including a flush-type lamp (such as a pulsed-xenon lamp) that emits high energy and wide wavelength intermittently. In this study, the difference between inactivation efficiencies by low-pressure UV (LPUV) and pulsed-xenon (PXe) lamps was investigated using two coliphage types and three strains of Escherichia coli. PXe had a suppressive effect on photoreactivation rate of the E. coli strains even though there was no significant effect on inactivation rate and maximum survival ratio after photoreactivation. PXe also had a benefit when applied to high turbidity waters as no tailing phenomena were observed in the low survival ratio area although it was observed in LPUV inactivation. This efficiency difference was considered to be due to the difference in irradiated wavelength of both lamps.

  17. Energy concentration and positional stability of sonoluminescent bubbles in sulfuric acid for different static pressures.

    Science.gov (United States)

    Rosselló, Juan Manuel; Dellavale, Damián; Bonetto, Fabián José

    2013-09-01

    In this study we report several experimental and numerical results on the influence of static pressure (P_{0}) over the main parameters in single bubble sonoluminescence (SBSL), using a sulfuric acid aqueous solution (SA) with low concentrations of argon gas dissolved. Bifrequency driving was used in the experiments to enhance spatial stability of the bubbles. The experimental results were compared with simulations provided by a numerical code that models the radial dynamics of the bubbles. The results showed that an increase on the static pressure of the system shifts the Bjerknes instability threshold, allowing the bubble to access higher acoustic pressures (P_{Ac}^{}). Furthermore, a decrease in the measured ambient radius R_{0} and the calculated relative gas concentration c_{∞}/c_{0} were observed. A notorious increment in the bubble collapse violence and energy focusing for P_{0} above 1 bar was achieved. These were mainly indicated by the growth of the bubble expansion ratio (R_{max}/R_{0}), the bubble mechanical energy density, and the maximum bubble wall velocity dR/dt. In agreement with the previous statement, the maximum temperature during the bubble collapse predicted by the model is augmented as well. The use of different harmonics in the ultrasound pressure field regarding energy focusing is also discussed. Finally, we analyzed the stability regions of the R_{0}-P_{Ac}^{} parameter space via numerical predictions for P_{0} above the measured, identifying the shape instabilities as the main limiting agent to obtain further energy concentration in SA systems at high static pressures.

  18. The effect of different depths of medial heel skive on plantar pressures

    Directory of Open Access Journals (Sweden)

    Bonanno Daniel R

    2012-08-01

    Full Text Available Abstract Background Foot orthoses are often used to treat lower limb injuries associated with excessive pronation. There are many orthotic modifications available for this purpose, with one being the medial heel skive. However, empirical evidence for the mechanical effects of the medial heel skive modification is limited. This study aimed to evaluate the effect that different depths of medial heel skive have on plantar pressures. Methods Thirty healthy adults (mean age 24 years, range 18–46 with a flat-arched or pronated foot posture and no current foot pain or deformity participated in this study. Using the in-shoe pedar-X® system, plantar pressure data were collected for the rearfoot, midfoot and forefoot while participants walked along an 8 metre walkway wearing a standardised shoe. Experimental conditions included a customised foot orthosis with the following 4 orthotic modifications: (i no medial heel skive, (ii a 2 mm medial heel skive, (iii a 4 mm medial heel skive and (iv a 6 mm medial heel skive. Results Compared to the foot orthosis with no medial heel skive, statistically significant increases in peak pressure were observed at the medial rearfoot – there was a 15% increase (p = 0.001 with the 4 mm skive and a 29% increase (p  Conclusions This study found that a medial heel skive of 4 mm or 6 mm increases peak pressure under the medial rearfoot in asymptomatic adults with a flat-arched or pronated foot posture. Plantar pressures at the midfoot and forefoot were not altered by a medial heel skive of 2, 4 or 6 mm. These findings provide some evidence for the effects of the medial heel skive orthotic modification.

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

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Heiselberg, Per

    2008-01-01

    direction, the turbulence characteristics in the wind and the pressure variations caused by e.g. wind gusts. Finally, it also depends on the size, type and location of the opening. Many of these parameters are unsteady which makes the calculation of air-change rates even more complicated. In this work, full......-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...

  20. 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.

  1. Study on law of raw coal seepage during loading process at different gas pressures

    Institute of Scientific and Technical Information of China (English)

    Meng Junqing; Nie Baisheng; Zhao Bi; Ma Yechao

    2015-01-01

    In order to reveal the law of raw coal seepage at different gas pressures, the gravity constant load seepage experimental system was developed and used. The law of raw coal seepage at different gas pressures with He, N2 and CO2 was investigated. The results show that, in a given state of stress during the experiment, with the increase of gas pressure, the permeability of raw coal sample prone to outburst exhibits a significantly decrease, and then exhibits an increasing trend when reaching the extreme point. The law of Klingberg coefficient related to the stress state and the gas adsorption properties was also obtained. Under the same experimental conditions, the Klingberg coefficient of He is greater than that of N2; and the Klingberg coefficient of CO2 has minimum value; so the stronger the gas adsorption is, the smaller the Klingberg coefficient of gas goes. Klinkenberg coefficient decreases with the increase of effective stress. Under the same conditions, the permeability of He is greater than that of N2; the permeability of CO2 has minimum value;so the stronger the gas adsorption is, the lower the permeability of the coal sample goes. The results have important significance in revealing the mechanism of gas seepage, predicting coal mine gas disaster, and gas drainage and safety production.

  2. Pressure generation at the junction of two microchannels with different depths.

    Science.gov (United States)

    Yanagisawa, Naoki; Dutta, Debashis

    2010-06-01

    In this study, we report the design of a microchip-based hydraulic pump that comprises three glass conduits arranged in a T-geometry, one of which has a 2 mm long segment shallower (0.5-3 microm in depth) than the remaining 15 microm deep microfluidic network. Upon application of an electric field across this microchannel junction, a mismatch in EOF rate is introduced due to a differential in the fluid conductivity across the deep and shallow segments. Using the reported micropump, pressure-driven velocities up to 3.2 mm/s have been generated in a 15 microm deep separation channel for an applied voltage of 1.75 kV allowing us to operate under separation conditions that yield the minimum plate height. Moreover, we have shown that this flow velocity can be maximized by optimizing the depth in the shallow region of the T-geometry. Interestingly however, a simple theory accounting for fluid conductivity differences across microchannels of different depths significantly underestimates the pressure-driven velocities observed in our experiments. The Taylor dispersion coefficient in our system on the other hand compares well with the theoretical predictions reported in the literature. Finally, the functionality of our device has been demonstrated by implementing a reverse-phase chromatographic separation that was driven by the pressure-driven flow generated on-chip.

  3. An Experimental Study on Atmospheric Pressure Glow Discharge in Different Gases

    Institute of Scientific and Technical Information of China (English)

    刘鹏; 詹如娟; 等

    2002-01-01

    Usually,the electrical breakdown of dielectric barrier discharge(DBD) at atmospheric pressure leads to a filamentary non-homogeneous discharge,However,it is also possible to obtain a diffuse DBD in homogeneous form,called atmospheric pressure glow discharge(APGD).We obtained a uniform APGD in helium and in the mixture of argon with alcohol,and studied the electrical characteristics of helium APGD.It if found that the relationship between discharge current and source frequency is different depending on the difference in gas gap when the applied voltage is kept constant.The discharge current shows an increasing trend with the increased frequency when gas gap is 0.8cm ,but the discharge current tends to decrease with the increased frequency when the gas gap increases.The discharge current always increases with the increased applied voltage when the source frequency is kept constant.We also observed a glow-like discharge in nitrogen at atmospheric pressure.

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

    Science.gov (United States)

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

    2016-09-01

    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.

  5. Comparison of the effects of four different cochlear implant electrodes on intra-cochlear pressure in a model.

    Science.gov (United States)

    Todt, Ingo; Mittmann, Marlene; Ernst, Arneborg; Mittmann, Philipp

    2017-03-01

    Based on this model experiment, a small tip and low volume electrode show lowest intra-cochlear pressure values. Insertional support by a tool minimizes fast pressure changes. Higher electrodes volumes affect slow and fast pressure changes as well. Insertion causing low intra-cochlear pressure is assumed to be important for atraumatic cochlear implant surgery to preserve residual hearing. Cochlear implant electrodes differ in terms of parameters like tip size, length, volume, and technique of insertion. The aim of this study was to observe the effect of different cochlear implant electrodes on insertional intra-cochlear pressure in a cochlear model. Cochlear implant electrode insertions were performed in an artificial cochlear model and intra-cochlear pressure changes were recorded in parallel with a micro-pressure sensor positioned in the apical region of the cochlear model to follow the maximum values, temporal changes, maximum amplitude, and frequency of changes in intra-cochlear pressure. Insertions were performed with four different electrodes (Advanced Bionics 1j, Helix, HFMS, and LW23). This study found statistically significant differences in the occurrence of initial maximum pressure values correlating with the electrode tip size. The different electrodes and the technique of insertion significantly affected the occurrence of maximum value, amplitude, and frequency of intra-cochlear pressure occurrence.

  6. 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

  7. 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.

  8. A thermophile under pressure: Transcriptional analysis of the response of Caldicellulosiruptor saccharolyticus to different H2 partial pressures

    NARCIS (Netherlands)

    Bielen, A.A.M.; Verhaart, M.R.A.; Vanfossen, A.L.; Blumer-Schuette, S.E.; Stams, A.J.M.; Oost, van der J.; Kelly, R.M.; Kengen, S.W.M.

    2013-01-01

    Increased hydrogen (H2) levels are known to inhibit H2 formation in Caldicellulosiruptor saccharolyticus. To investigate this organism's strategy for dealing with elevated H2 levels the effect of the hydrogen partial pressure (PH2) on fermentation performance was studied by growing cultures under

  9. Adult derived genetic blood pressure scores and blood pressure measured in different body postures in young children

    NARCIS (Netherlands)

    Jansen, Maria Ac; Dalmeijer, Geertje W.; Visseren, Frank Lj; van der Ent, Cornelis K; Leusink, Maarten; Onland-Moret, N Charlotte; Der Zee, Anke H Maitland Van; Grobbee, Diederick E; Uiterwaal, CSPM

    2017-01-01

    Aims Several genes are related to blood pressure (BP) levels in adults, but it is largely unknown whether these genes also determine BP early in life. Methods Systolic BP (SBP) and diastolic BP (DBP) were measured in 720 5-year-old children from the WHeezing-Illnesses-STudy-LEidsche-Rijn (WHISTLER)

  10. A thermophile under pressure: Transcriptional analysis of the response of Caldicellulosiruptor saccharolyticus to different H2 partial pressures

    NARCIS (Netherlands)

    Bielen, A.A.M.; Verhaart, M.R.A.; Vanfossen, A.L.; Blumer-Schuette, S.E.; Stams, A.J.M.; Oost, van der J.; Kelly, R.M.; Kengen, S.W.M.

    2013-01-01

    Increased hydrogen (H2) levels are known to inhibit H2 formation in Caldicellulosiruptor saccharolyticus. To investigate this organism's strategy for dealing with elevated H2 levels the effect of the hydrogen partial pressure (PH2) on fermentation performance was studied by growing cultures under hi

  11. The Effect of Different Foot Orthosis Inverted Angles on Plantar Pressure in Children with Flexible Flatfeet

    Science.gov (United States)

    Lee, Hyunkeun; Ahn, Soyoung; Song, Youngshin; Park, Insik

    2016-01-01

    Although orthotic modification using the inverted technique is available for the treatment of flatfoot, empirical evidence for the biomechanical effects of inverted-angle foot orthoses (FOs) is lacking. The aim of this study was to evaluate the effects of different FO inversion angles on plantar pressure during gait in children with flatfoot. Twenty-one children with flexible flatfeet (mean age 9.9 years) were enrolled in this study. The plantar pressures were measured for the rearfoot; medial and lateral midfoot; and medial, central, and lateral forefoot as participants walked on a treadmill while wearing shoes only and shoes with the following 3 orthotic conditions: (i) orthosis with no inverted angle, (ii) orthosis with a 15° inverted angle, and (iii) orthosis with a 30° inverted angle. A one-way repeated measures analysis of variance (ANOVA) with the Bonferroni-adjusted post-hoc test was used to compare the mean values of each orthotic condition. Compared with the shoe only condition, the peak pressure decreased significantly under the medial forefoot and rearfoot with all FOs (p flatfoot. PMID:27458719

  12. Comparative studies on toluene removal and pressure drop in biofilters using different packing materials.

    Science.gov (United States)

    Ryu, Hee Wook; Kim, So Jung; Cho, Kyung Suk

    2010-05-01

    To select the best available packing material for malodorous organic gases such as toluene and benzene, biofilter performance was compared in biofilters employed different packing materials including porous ceramic (celite), Jeju scoria (lava), a mixture of granular activated carbon (GAC) and celite (GAC/celite), and cubic polyurethane foam (PU). A toluene-degrading bacterium, Stenotrophomonas maltophilia T3-c, was used as the inoculum. The maximum elimination capacities in the celite, lava, and GAC/celite biofilters were 100, 130, and 110 gm(-3) hr(-1), respectively. The elimination capacity for the PU biofilter was approximately 350 g m(-3) hr(-1) at an inlet loading of approximately 430 g m(-3) hr(-1), which was 2 to 3.5 times higher than for the other biofilters. The pressure drop gradually increased in the GAC/ celite, celite and lava biofilters after 23 day due to bacterial over-growth, and the toluene removal efficiency remarkably decreased with increasing pressure drop. Backwashing method was not effective for the control of biomass in these biofilters. In the PU biofilter however, backwashing allowed maintenance of a pressure drop of 1 to 3 mm H2O m(-1) and a removal efficiency of > 80%, indicating that the PU was the best packing material for toluene removal among the packing materials tested.

  13. Maximal respiratory static pressures in patients with different stages of COPD severity

    Directory of Open Access Journals (Sweden)

    Ricci Alberto

    2008-01-01

    Full Text Available Abstract Background In this study, we analyzed maximal inspiratory pressure (MIP and maximal expiratory pressure (MEP values in a stable COPD population compared with normal subjects. We evaluated the possible correlation between functional maximal respiratory static pressures and functional and anthropometric parameters at different stages of COPD. Furthermore, we considered the possible correlation between airway obstruction and MIP and MEP values. Subject and methods 110 patients with stable COPD and 21 age-matched healthy subjects were enrolled in this study. Patients were subdivided according to GOLD guidelines: 31 mild, 39 moderate and 28 severe. Results Both MIP and MEP were lower in patients with severe airway impairment than in normal subjects. Moreover, we found a correlation between respiratory muscle function and some functional and anthropometric parameters: FEV1 (forced expiratory volume in one second, FVC (forced vital capacity, PEF (peak expiratory flow, TLC (total lung capacity and height. MIP and MEP values were lower in patients with severe impairment than in patients with a slight reduction of FEV1. Conclusion The measurement of MIP and MEP indicates the state of respiratory muscles, thus providing clinicians with a further and helpful tool in monitoring the evolution of COPD.

  14. The effects of upper body exercise across different levels of blood flow restriction on arterial occlusion pressure and perceptual responses.

    Science.gov (United States)

    Mattocks, Kevin T; Jessee, Matthew B; Counts, Brittany R; Buckner, Samuel L; Grant Mouser, J; Dankel, Scott J; Laurentino, Gilberto C; Loenneke, Jeremy P

    2017-03-15

    Recent studies have investigated relative pressures that are applied during blood flow restriction exercise ranging from 40%-90% of resting arterial occlusion pressure; however, no studies have investigated relative pressures below 40% arterial occlusion pressure. The purpose of this study was to characterize the cardiovascular and perceptual responses to different levels of pressures. Twenty-six resistance trained participants performed four sets of unilateral elbow flexion exercise using 30% of their 1RM in combination with blood flow restriction inflated to one of six relative applied pressures (0%, 10%, 20%, 30%, 50%, 90% arterial occlusion pressure). Arterial occlusion pressure was measured before (pre) and immediately after the last set of exercise at the radial artery. RPE and discomfort were taken prior to (pre) and following each set of exercise. Data presented as mean (95% CI) except for perceptual responses represented as the median (25th, 75th percentile). Arterial occlusion pressure increased from pre to post (pexercise (pexercise. Applying higher relative pressures results in the greatest cardiovascular response, higher perceptual ratings, and greater decrease in exercise volume compared to lower restriction pressures. Therefore, the perceptual responses from lower relative pressures may be more appealing and provide a safer and more tolerable stimulus for individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Blood pressure differences by ethnic group among United States children and adolescents.

    Science.gov (United States)

    Rosner, Bernard; Cook, Nancy; Portman, Ron; Daniels, Steve; Falkner, Bonita

    2009-09-01

    Large differences in blood pressure (BP) by ethnic group are apparent among adults. There is uncertainty as to whether similar differences by ethnic group exist among children and, if so, the age of onset. BP measurements were obtained from 58 698 children at 78 556 visits using Pediatric Task Force data, a collection of 11 studies with BP data from children and adolescents age 1 to 17 years. Generalized estimating equation methods were used to identify sex-specific differences in body mass index (BMI)-adjusted rates of BP elevation and prehypertension by ethnic group. Significant BMI-adjusted differences in rates of BP elevation were found between Hispanic boys versus white boys (odds ratio: 1.21; 95% CI: 1.07 to 1.37; P=0.002). No overall significant differences were found between black boys versus white boys (odds ratio: 1.03; 95% CI: 0.95 to 1.12; P=0.49); however, there was significant effect modification (P=0.01) with significant differences found for normal-weight boys (BMI: or =85th percentile; OR black versus white: 0.90; 95% CI: 0.78 to 1.05; P=0.20). No overall ethnic group differences in BMI-adjusted rates of hypertension were found for girls. Ethnic differences in prevalence rates of pediatric BP elevation that are not explained by obesity are present, primarily in boys. Whether these differences are attributable to genetic or environmental factors is unknown.

  16. An acute bout of aerobic exercise alters interarm systolic blood pressure difference.

    Science.gov (United States)

    Holmstrup, Michael E; Clarke, Melanie M; Conner, Cailin R; Jensen, Brock T

    2017-04-01

    Clinically, when a difference of at least 10 mmHg in systolic blood pressure (SBP) between arms exists, it is identified as an interarm systolic blood pressure difference (ISBPD). At rest, ISBPD is linked with hypertension, peripheral vascular disease, and increased premature mortality. Exercise may reveal underlying cardiovascular pathologies otherwise absent at rest. However, there have been no investigations to examine the effect of exercise on ISBPD. The aim of this investigation was to determine whether exercise may alter ISBPD when detected at rest or reveal ISBPD when it was not observed in the resting condition. An experienced investigator sequentially measured SBP using standard auscultation in each arm (alternating order) in 85 normotensive individuals (22±6 years, 39 male, 46 female). ISBPD was quantified before exercise (PRE). Participants then completed a three-stage protocol on a cycle ergometer. A cadence of 50 rpm was maintained at a workload of 3 (EX-3; light) and 6 (EX-6; moderate) METS and during an active recovery (REC). At each stage, SBP was measured upon achieving steady-state heart rate. A logistic regression analysis was used to determine the change in odds ratio of ISBPD when exposed to exercise. Thirteen percent (n=11) of patients presented with ISBPD during PRE and the degree of ISBPD was lower (3.81 mmHg; Pexercise attenuated the difference between interarm SBP. Moderate-intensity exercise resulted in ISBPD not otherwise present at rest.

  17. 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

    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. PMID:26083600

  18. Development of Resistance to Pyrethroid in Culex pipiens pallens Population under Different Insecticide Selection Pressures.

    Science.gov (United States)

    Shi, Linna; Hu, Hongxia; Ma, Kai; Zhou, Dan; Yu, Jing; Zhong, Daibin; Fang, Fujin; Chang, Xuelian; Hu, Shengli; Zou, Feifei; Wang, Weijie; Sun, Yan; Shen, Bo; Zhang, Donghui; Ma, Lei; Zhou, Guofa; Yan, Guiyun; Zhu, Changliang

    2015-01-01

    Current vector control programs are largely dependent on pyrethroids, which are the most commonly used and only insecticides recommended by the World Health Organization for insecticide-treated nets (ITNs). However, the rapid spread of pyrethroid resistance worldwide compromises the effectiveness of control programs and threatens public health. Since few new insecticide classes for vector control are anticipated, limiting the development of resistance is crucial for prolonging efficacy of pyrethroids. In this study, we exposed a field-collected population of Culex pipiens pallens to different insecticide selection intensities to dynamically monitor the development of resistance. Moreover, we detected kdr mutations and three detoxification enzyme activities in order to explore the evolutionary mechanism of pyrethroid resistance. Our results revealed that the level of pyrethroid resistance was proportional to the insecticide selection pressure. The kdr and metabolic resistance both contributed to pyrethroid resistance in the Cx. pipiens pallens populations, but they had different roles under different selection pressures. We have provided important evidence for better understanding of the development and mechanisms of pyrethroid resistance which may guide future insecticide use and vector management in order to avoid or delay resistance.

  19. Effect of Porous Pipe Characteristics on Soil Wetting Pattern in a Negative Pressure Difference Irrigation System

    Directory of Open Access Journals (Sweden)

    Nurun Nahar Khan

    2015-02-01

    Full Text Available Sub-surface irrigation has been widely used to reduce conveyance, evaporation and percolation losses. This system involves the application of water directly into the root zone of crops. Negative Pressure Difference Irrigation (NPDI is one kind of subsurface irrigation which is effective in management of irrigation water. The efficiency of this system is dependent on the soil wetting pattern as well as the characteristics of porous pipe. To examine the effect of characteristics of six different porous pipes on soil wetting pattern using NPDI system, experiments were done in laboratory at a negative pressure (Pn of -3 cm. That Pn was generated by placing water reservoir in a lower level than porous pipe, which was installed vertically at the center of soil column. The water was supplied for four hours and after removing dry soil from the column wetted soil was observed. The experimental results show that the soil wetting pattern varies for each type of porous pipe. The study reveals that the shape of the wetted soil is roughly truncated sphere. The maximum vertical expansion and maximum radial expansion vary with the change in diameter and length of porous pipes. With the change in diameter of 128.6%, the maximum radial expansion differs from 24.1% and 34.48% for X and Y axis respectively. Since the water use efficiency is in the range of 0.94 to 0.97, this advanced method can be used as alternative of other traditional methods

  20. 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.

  1. Development of Resistance to Pyrethroid in Culex pipiens pallens Population under Different Insecticide Selection Pressures.

    Directory of Open Access Journals (Sweden)

    Linna Shi

    Full Text Available Current vector control programs are largely dependent on pyrethroids, which are the most commonly used and only insecticides recommended by the World Health Organization for insecticide-treated nets (ITNs. However, the rapid spread of pyrethroid resistance worldwide compromises the effectiveness of control programs and threatens public health. Since few new insecticide classes for vector control are anticipated, limiting the development of resistance is crucial for prolonging efficacy of pyrethroids. In this study, we exposed a field-collected population of Culex pipiens pallens to different insecticide selection intensities to dynamically monitor the development of resistance. Moreover, we detected kdr mutations and three detoxification enzyme activities in order to explore the evolutionary mechanism of pyrethroid resistance. Our results revealed that the level of pyrethroid resistance was proportional to the insecticide selection pressure. The kdr and metabolic resistance both contributed to pyrethroid resistance in the Cx. pipiens pallens populations, but they had different roles under different selection pressures. We have provided important evidence for better understanding of the development and mechanisms of pyrethroid resistance which may guide future insecticide use and vector management in order to avoid or delay resistance.

  2. Measurement of arm blood pressure using different oscillometry manometers compared to auscultatory readings.

    Science.gov (United States)

    Shahriari, Majid; Rotenberg, Daniel Kaminski; Nielsen, Jesper Kent; Wiinberg, Niels; Nielsen, Poul Ebbe

    2003-01-01

    Five different semiautomatic manometers were tested, where oscillometry is the measuring principle. Three of the manometers (Omron R4, A&D UB 322 and Braun) were wrist manometers, where the occluding cuff is placed around the volar surface of the wrist. Two of the manometers (A&D UA 777 and Omron M4) measure on the upper arm. The investigation included 72 patients with systolic blood pressure (SBP) ranging between 110 and 200, and diastolic blood pressure (DBP) between 62 and 114 mmHg. Forty-five of the subjects were on antihypertensive medication when the manometer tests were carried out. Each of the manometers was tested with double measurements of blood pressure against 2 x 2 auscultatory measurements done before and after the semiautomatic readings. The auscultatory measurements are all performed by the same observer, who was blinded for the measurements with semiautomatic manometers. The mean difference between the oscillometric recordings compared to auscultatory measurements varied from +1.2 to -8.5 mmHg for SBP and from -0.5 to -8.3 mmHg for DBP. However, the interindividual differences varied considerable with standard deviation of the difference varying from 8 to 18 mmHg for SBP with the highest values for wrist manometers. Concerning DBP, the standard deviation of difference for all five manometers was between 6 and 8 mmHg, with the highest values for wrist manometers. None of the tested manometers fulfilled the criteria for grading A or B in the previously introduced grading by the British Hypertension Society. To conclude, the upper-arm manometers have a measuring accuracy for SBP a little higher than that of the wrist manometers, while there is no bigger difference in the measuring accuracy of DBP. The most important point is that the measuring accuracy in a single patient is unpredictable. If home readings are prepared, a test of the accuracy against auscultatory recordings should be done in every single patient. In the clinical wards, it is

  3. THE RAMAN SCATTERING OF CARBON NANOTUBES PRODUCED IN DIFFERENT INERT GASES AND THEIR PRESSURES BY ARC DISCHARGE

    Institute of Scientific and Technical Information of China (English)

    ZHANG HAI-YAN; CHEN JIAN; LIU SONG-HAO; CHEN DI-HU; WU CHUN-YAN; HE YAN-YANG; LIANG LI-ZHENG; PENG SHAO-QI

    2000-01-01

    First- and second-order Raman spectra of carbon nanotubes produced in helium and argon atmospheres at a pressure ranging from 11 to 92 kPa by arc discharge have been measured and compared with each other. The position and bandwidth of the spectral lines depend on the kind of inert gases and their pressure. The Raman spectra of the nanotubes produced in argon gas atmosphere are much more similar to that of polycrystalline graphite than those of the nanotubes produced in helium gas atmosphere. The position and bandwidth of nanotube Raman peaks change with gas pressure in arc discharge because different diameter distribution of nanotubes is produced at different inert gas pressure. The Raman spectra of nanotubes produced at high pressure is much more like that of graphite than those produced in lower pressure

  4. [Monitoring of intracranial pressure difference between supra- and infratentorial spaces after posterior fossa tumor removal (case report)].

    Science.gov (United States)

    Oshorov, A V; Savin, I A; Goriachev, A S; Popugaev, K A; Lubnin, A Iu

    2011-01-01

    A clinical example shows that after a neurosurgical operation in posterior fossa there could appear intracranial pressure difference between supra- and infratentorial spaces. This difference develops due to pressure rise in posterior fossa and maintenance of this hypertension postoperatively. Hypertension in posterior fossa and intracranial difference are accompanied by brainstem reactions and temporary neurological disorders. While the pressure difference decreases and ICP in posterior fossa normalizes the neurological symptoms disappear. ICP in supratentorial space not necessarily correlates with ICP in infratentorial space. In some cases it is necessary to measure ICP in infratentorial space after posterior fossa surgery.

  5. Shear viscosity and normal pressure differences in the scope of the extended Kirkwood-Smoluchowski equation

    Science.gov (United States)

    Koo, H.-M.

    1993-03-01

    The potential contribution to the viscosity in liquids is calculated from the pair-correlation function, which may be obtained by solving the extended Kirkwood-Smoluchowski (KS) equation. A secondary boundary condition near the hard core (r=1+) for the excess pair probability current density in the relative pair space is derived rigorously and applied to the extended KS equation. The intermolecular potential consists of hard core plus arbitrary soft tail. The viscosity coefficients calculated in this work prove to be essentially functions of the square root of the shear rate rather than functions of the shear rate itself. We give the explicit representation for the viscosity coefficients in the case of hard spheres. The shear thinning of the shear viscosity is recovered. The viscosity of the normal pressure difference 1/2(pxx-pyy) is found to be positive. The normal pressure difference of the second kind 1/2[pzz-1/2(pxx+pyy)] vanishes in the first-order perturbation calculation with respect to the deformation.

  6. Pressure-selective modulation of NMDA receptor subtypes may reflect 3D structural differences

    Directory of Open Access Journals (Sweden)

    Amir eMor

    2012-09-01

    Full Text Available Professional deep-water divers exposed to high pressure (HP above 1.1 MPa suffer from High Pressure Neurological Syndrome (HPNS, which is associated with CNS hyperexcitability. We have previously reported that HP augments N-methyl-D-aspartate receptor (NMDAR synaptic responses, increases neuronal excitability, and potentially causes irreversible neuronal damage. We now report that HP (10.1 MPa differentially affects eight specific NMDAR subtypes. GluN1(1a or 1b was co-expressed with one of the four GluN2(A-D subunits in Xenopus laevis oocytes. HP increased ionic currents (measured by two electrode voltage clamps of one subtype, reduced the current in four others, and did not affect the current in the remaining three. 3D theoretical modeling was aimed at revealing specific receptor domains involved with HP selectivity. In light of the information on the CNS spatial distribution of the different NMDAR subtypes, we conclude that the NMDAR’s diverse responses to HP may lead to selective HP effects on different brain regions. These discoveries call for further and more specific investigation of deleterious HP effects and suggest the need for a re-evaluation of deep-diving safety guidelines.

  7. Differences in quantitative characteristics of intracranial pressure in hydrocephalic children treated surgically or conservatively.

    Science.gov (United States)

    Eide, Per Kristian; Due-Tønnessen, Bernt; Helseth, Eirik; Lundar, Tryggve

    2002-06-01

    This study reports the results of quantitative analysis of continuous intracranial pressure (ICP) recordings in 33 hydrocephalic children. The aim of the study was to compare the exact numbers of increases in ICP during sleep or the awake state in hydrocephalic children who were treated either surgically or conservatively. At the time of ICP monitoring, the ICP curves were assessed by the calculation of mean ICP and visual inspection for the detection of plateau waves. Quantitative analysis was performed with the software Sensometrics Pressure Analyser, which presented the ICP curve as a matrix of numbers of ICP elevations of different levels (20-40 mm Hg) and durations (0.5-20 min). In each case, the numbers of ICP elevations were standardized to 10 h of recording time, providing the opportunity for comparisons of ICP curves between individuals. Compared to the surgery group, there was a rather high number of ICP elevations of 20 mm Hg of various durations in the nonsurgery group, e.g. ICP elevations of 20 mm Hg lasting 10 min occurred in 13 of 19 children (68%) in the nonsurgery group. There was no apparent relationship between ICP and age or between the size of the cerebral ventricles and ICP. In children with hydrocephalus, the presentation of the ICP data as a matrix of ICP elevations of different levels and durations may enhance the informative value of continuous ICP monitoring, as compared to the calculation of mean ICP and visual detection of plateau waves. Copyright 2002 S. Karger AG, Basel

  8. Pressure-selective modulation of NMDA receptor subtypes may reflect 3D structural differences.

    Science.gov (United States)

    Mor, Amir; Kuttner, Yosef Y; Levy, Shiri; Mor, Merav; Hollmann, Michael; Grossman, Yoram

    2012-01-01

    Professional deep-water divers exposed to high pressure (HP) above 1.1 MPa suffer from High Pressure Neurological Syndrome (HPNS), which is associated with CNS hyperexcitability. We have previously reported that HP augments N-methyl-D-aspartate receptor (NMDAR) synaptic responses, increases neuronal excitability, and potentially causes irreversible neuronal damage. We now report that HP (10.1 MPa) differentially affects eight specific NMDAR subtypes. GluN1(1a or 1b) was co-expressed with one of the four GluN2(A-D) subunits in Xenopus laevis oocytes. HP increased ionic currents (measured by two electrode voltage clamps) of one subtype, reduced the current in four others, and did not affect the current in the remaining three. 3D theoretical modeling was aimed at revealing specific receptor domains involved with HP selectivity. In light of the information on the CNS spatial distribution of the different NMDAR subtypes, we conclude that the NMDAR's diverse responses to HP may lead to selective HP effects on different brain regions. These discoveries call for further and more specific investigation of deleterious HP effects and suggest the need for a re-evaluation of deep-diving safety guidelines.

  9. Baroclinic pressure gradient difference schemes of subtracting the local averaged density stratification in sigma coordinates models

    Institute of Scientific and Technical Information of China (English)

    ZHU Shouxian; ZHANG Wenjing

    2008-01-01

    Much has been written of the error in computing the baroclinic pressure gradient (BPG) with sigma coordinates in ocean or atmos- pheric numerical models. The usual way to reduce the error is to subtract area-averaged density stratification of the whole computa- tion region. But if there is great difference between the area-averaged and the local averaged density stratification, the error will be obvious. An example is given to show that the error from this method may be larger than that from no correction sometimes. The definition of local area is put forward. Then, four improved BPG difference schemes of subtracting the local averaged density strat- ification are designed to reduce the error. Two of them are for diagnostic calculation (density field is fixed), and the others are for prognostic calculation (density field is not fixed). The results show that the errors from these schemes all significantly decrease.

  10. Effect of high pressure high temperature processing on the volatile fraction of differently coloured carrots.

    Science.gov (United States)

    Kebede, Biniam T; Grauwet, Tara; Palmers, Stijn; Vervoort, Liesbeth; Carle, Reinhold; Hendrickx, Marc; Van Loey, Ann

    2014-06-15

    To get deeper insight into the effect of high pressure high temperature (HPHT) processing on the volatile fraction of carrots, differently coloured cultivars exhibiting orange, purple, red and yellow hues were investigated. The impact of HPHT sterilisation was compared with thermal sterilisation based on equivalent microbiological inactivation. The results of this study demonstrated HPHT sterilisation to exert a distinct effect on important chemical reactions in comparison to thermal sterilisation. A comprehensive integration of MS-based metabolomic fingerprinting (HS-SPME-GC-MS) and chemometric tools has been implemented as an untargeted multivariate screening tool to identify differences. In all carrot cultivars, two dominant discriminative quality-related reactions were found: oxidative degradation and the Maillard reaction. Regarding the first reaction, oxidative terpenes, free fatty acids and carotenoids degradation products were detected at higher levels after HPHT sterilisation. Regarding the latter reaction, HPHT sterilisation appeared to suppress the formation of Maillard and Strecker degradation products.

  11. 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...

  12. [Study on plantaer pressure distribution of people walking with different backpack load].

    Science.gov (United States)

    Chen, Hao; Liu, Herong; Zhang, Jianguo; Qiao, Gang

    2013-06-01

    The purpose of this study was to investigate the effect of different backpack load on the plantar pressure of people during walking. By using three-dimensional force platform system, we collected the ground reaction force data from 20 college students, who were carrying different loads on their backs, and then we transformed the data into a characteristic two-peak curve. Seven characteristic parameters on the curve were selected and analyzed by using statistical methods. The results indicated that the peak ground reaction forces increased as the loads increased. Furthermore, in consideration of different genders, the amount increased was different. For the male subjects, when backpack load reached 17% body weight, changes in ground reaction force began to take place until the backloads reached 20% body weight changes in ground reaction force induced a significant difference. Por the female subjects, changes in ground reaction force began to take place with loads up to 14% body weight and while it reached 15% body weight it induced a significant difference.

  13. Pressure load on specific body areas of gestating sows lying on rubber mats with different softness.

    Science.gov (United States)

    Schubbert, A; Hartung, E; Schrader, L

    2014-08-01

    Rubber mats offer a possibility to increase lying comfort for sows with positive effects on sow lying behavior and health. However, until now, no information has been reported about the relationship between the softness of rubber mats and the pressure load on certain body areas of sows. We used a total of 68 (40 multiparous, 28 primiparous) German Landrace × German Landrace sows with a BW within the range of 90 to 330 kg (divided in 3 weight classes) to measure peak force and distribution of pressure during lying in the sternal and half recumbent position. Measures were done in an experimental pen that was equipped with a pressure sensor map system (5400 NTL; Tekscan Inc., Boston, MA). Three rubber mats differing in softness (penetration depth: hard mat, 4.0 mm [HM]; soft mat, 14.6 mm [SM]; very soft mat, 43.0 mm [VSM]) were tested and compared to concrete floor (CF) as a reference. Pressure load was analyzed in the sternal position for the sternum, belly, and ham body regions and also in the half recumbent position for the shoulder. For each lying position we determined the body region with the highest pressure load and analyzed the peak force (PF) and the contact area (CA) using a mixed model ANOVA (MIXED procedure of SAS Enterprise, version 4.3., SAS Inst. Inc., Cary, NC) with floor type, weight class of sows, and their interaction as fixed factors. Overall, the highest values for PF in the sternal position were found on the sternum (median: 1.62 N/cm(2)) and in the half recumbent position on the shoulder (median: 2.72 N/cm(2)). In the sternal position PF on the sternum was lower on VSM compared to CF (P = 0.001). In the half-recumbent position PF on the shoulder was lower on VSM compared to CF (P = 0.013) and compared to HM (P = 0.011). The weight of the sows affected PF on the sternum in the sternal position, with lower values in weight class 1 compared to weight class 2 (P = 0.001) and weight class 3 (P = 0.002). Contact area under the sternum was larger on

  14. Analytical solution for spatially axisymmetric problem of thick-walled cylinder subjected to different linearly varying pressures along the axis and uniform pressures at two ends

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To our best knowledge,in the open literature,there is no analytical solution of thick-walled cylinder subjected to uniform pressures at two ends and different inner-and outer-surface pressures that are constant circumferentially but vary linearly at different rates along the axis.We now present such a solution.After repeated trials,we have finally succeeded in finding a necessary new displacement function.Based on A.E.H.Love method,the stress,displacement and volume strain formulas are derived by using the new displacement function.The present results include the Lamé’s formulas as special cases.Furthermore,the results obtained here can be applied to not only the thick-walled cylinders subjected to uniform pressures on the inner and outer surface of the thick-walled cylinder,respectively,but also the cylinders subjected to uniform pressures at two ends and dif- ferent inner-and outer-surface pressures that are constant circumferentially but vary linearly at different rates along the axis,respectively.Finally we give a numerical example to compare our exact method with the approximate method.

  15. Effect of different flooring systems on weight and pressure distribution on claws of dairy cows.

    Science.gov (United States)

    Telezhenko, E; Bergsten, C; Magnusson, M; Ventorp, M; Nilsson, C

    2008-05-01

    Weight and pressure distribution on the claw were studied in Swedish Holsteins housed in different flooring systems. A total of 127 cows housed in different sections of the experimental barn were used. Each section had different flooring in the walking and standing areas. There were rubber mats or abrasive mastic asphalt flooring on the alleys or a low-abrasive slatted concrete floor. Some sections had feed-stalls equipped with rubber mats; other sections did not. The vertical ground reaction force, contact area, and average contact pressure were determined on the left hind foot using the I-Scan system and analyzed with the F-scan system. These determinations were made in each of the following 3 zones of the claw: bulb, wall, and sole. Most of the weight on claws exposed to concrete floors was carried by the bulb (37.4 +/- 3.5 and 18.3 +/- 2.9% of weight exerted on the foot in the lateral and medial claw, respectively) and the wall zone (20.0 +/- 2.6 and 13.4 +/- 2.4% on lateral and medial claw, respectively). The weight and pressure distribution in cows kept on sections with rubber covered alleys but passing daily over the asphalt floor on their way to the milking parlor did not differ in any zones, except for lateral bulbs, compared with those exposed to slatted concrete alone. Still, the weight bearing of the sole zone in cows kept on rubber mats without access to asphalt was less than that of cows kept on concrete slatted floors (5.1 +/- 0.7 vs. 12.7 +/- 1.1% and 1.1 +/- 0.5 vs. 8.7 +/- 0.7% in lateral and medial claws, respectively). In cows kept on asphalt flooring without feed-stalls, most weight was exerted to the sole zone (36.2 +/- 2.9 and 22.2 +/- 1.8% in lateral and medial claws, respectively). Feed-stalls in combination with asphalt flooring yielded a decreased total contact area (30.1 +/- 1.2 cm(2)) compared with asphalt floors without feed-stalls (35.7 +/- 1.2 cm(2)). The largest total contact area was obtained on the asphalt floor without feed

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

    Science.gov (United States)

    Brito, Aline de Freitas; de Oliveira, Caio Victor Coutinho; Brasileiro-Santos, Maria do Socorro; Santos, Amilton da Cruz

    2014-01-01

    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 resistance. PMID:25540580

  17. 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.

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

    Science.gov (United States)

    Brito, Aline de Freitas; de Oliveira, Caio Victor Coutinho; Brasileiro-Santos, Maria do Socorro; Santos, Amilton da Cruz

    2014-01-01

    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. The study was conducted with ten hypertensive elderly (65±3 years, 28.7±3 kg/m(2)) 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. 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, Pexercises 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 resistance.

  19. 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...

  20. Prediction of Three-Dimensional Downward Flame Spread Characteristics over Poly(methyl methacrylate) Slabs in Different Pressure Environments.

    Science.gov (United States)

    Zhao, Kun; Zhou, Xiao-Dong; Liu, Xue-Qiang; Lu, Lei; Wu, Zhi-Bo; Peng, Fei; Ju, Xiao-Yu; Yang, Li-Zhong

    2016-11-22

    The present study is aimed at predicting downward flame spread characteristics over poly(methyl methacrylate) (PMMA) with different sample dimensions in different pressure environments. Three-dimensional (3-D) downward flame spread experiments on free PMMA slabs were conducted at five locations with different altitudes, which provide different pressures. Pressure effects on the flame spread rate, profile of pyrolysis front and flame height were analyzed at all altitudes. The flame spread rate in the steady-state stage was calculated based on the balance on the fuel surface and fuel properties. Results show that flame spread rate increases exponentially with pressure, and the exponent of pressure further shows an increasing trend with the thickness of the sample. The angle of the pyrolysis front emerged on sample residue in the width direction, which indicates a steady-burning stage, varies clearly with sample thicknesses and ambient pressures. A global non-dimensional equation was proposed to predict the variation tendency of the angle of the pyrolysis front with pressure and was found to fit well with the measured results. In addition, the dependence of average flame height on mass burning rate, sample dimension and pressure was proposed based on laminar diffusion flame theory. The fitted exponent of experimental data is 1.11, which is close to the theoretical value.

  1. Application and Comparison of Different Combustion Models of High Pressure LOX/CH4 Jet Flames

    Directory of Open Access Journals (Sweden)

    Maria Grazia De Giorgi

    2014-01-01

    Full Text Available The present work focuses on the numerical modeling of combustion in liquid-propellant rocket engines. Pressure and temperature are well above thermodynamic critical points of both the propellants and then the reactants show liquid-like characteristics of density and gas-like characteristics for diffusivity. The aim of the work is an efficient numerical description of the phenomena and RANS simulations were performed for this purpose. Hence, in the present work different kinetics, combustion models and thermodynamic approaches were used for combustion modeling first in a trans-critical environment, then in the sub-critical state. For phases treatment the pure Eulerian single phase approach was compared with the Lagrangian/Eulerian description. For modeling combustion, the Probability Density Function (PDF equilibrium and flamelet approaches and the Eddy Dissipation approach, with two different chemical kinetic mechanisms (the Jones-Lindstedt and the Skeletal model, were used. Real Gas (Soave-Redlich-Kwong and Peng-Robinson equations were applied. To estimate the suitability of different strategies in phenomenon description, a comparison with experimental data from the literature was performed, using the results for different operative conditions of the Mascotte test bench: trans-critical and subcritical condition for oxygen injection. The main result of this study is the individuation of the DPM approach of the most versatile methods to reproduce cryogenic combustion adapted for different operating conditions and producing good results.

  2. A mimetic finite difference method for two-phase flow models with dynamic capillary pressure and hysteresis

    CERN Document Server

    Zhang, Hong

    2016-01-01

    Saturation overshoot and pressure overshoot are studied by incorporating dynamic capillary pressure, capillary pressure hysteresis and hysteretic dynamic coefficient with a traditional fractional flow equation. Using the method of lines, the discretizations are constructed by applying Castillo-Grone's mimetic operators in the space direction and explicit trapezoidal integrator in the time direction. Convergence tests and conservation property of the schemes are presented. Computed profiles capture both the saturation overshoot and pressure overshoot phenomena. Comparisons between numerical results and experiments illustrate the effectiveness and different features of the models.

  3. Noninvasive pressure difference mapping derived from 4D flow MRI in patients with unrepaired and repaired aortic coarctation.

    Science.gov (United States)

    Rengier, Fabian; Delles, Michael; Eichhorn, Joachim; Azad, Yoo-Jin; von Tengg-Kobligk, Hendrik; Ley-Zaporozhan, Julia; Dillmann, Rüdiger; Kauczor, Hans-Ulrich; Unterhinninghofen, Roland; Ley, Sebastian

    2014-04-01

    To develop a method for computing and visualizing pressure differences derived from time-resolved velocity-encoded three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) and to compare pressure difference maps of patients with unrepaired and repaired aortic coarctation to young healthy volunteers. 4D flow MRI data of four patients with aortic coarctation either before or after repair (mean age 17 years, age range 3-28, one female, three males) and four young healthy volunteers without history of cardiovascular disease (mean age 24 years, age range 20-27, one female, three males) was acquired using a 1.5-T clinical MR scanner. Image analysis was performed with in-house developed image processing software. Relative pressures were computed based on the Navier-Stokes equation. A standardized method for intuitive visualization of pressure difference maps was developed and successfully applied to all included patients and volunteers. Young healthy volunteers exhibited smooth and regular distribution of relative pressures in the thoracic aorta at mid systole with very similar distribution in all analyzed volunteers. Patients demonstrated disturbed pressures compared to volunteers. Changes included a pressure drop at the aortic isthmus in all patients, increased relative pressures in the aortic arch in patients with residual narrowing after repair, and increased relative pressures in the descending aorta in a patient after patch aortoplasty. Pressure difference maps derived from 4D flow MRI can depict alterations of spatial pressure distribution in patients with repaired and unrepaired aortic coarctation. The technique might allow identifying pathophysiological conditions underlying complications after aortic coarctation repair.

  4. Differences in predatory pressure on terrestrial snails by birds and mammals

    Indian Academy of Sciences (India)

    Zuzanna M Rosin; Paulina Olborska; Adrian Surmacki; Piotr Tryjanowski

    2011-09-01

    The evolution of shell polymorphism in terrestrial snails is a classic textbook example of the effect of natural selection in which avian and mammalian predation represents an important selective force on gene frequency. However, many questions about predation remain unclear, especially in the case of mammals. We collected 2000 specimens from eight terrestrial gastropod species to investigate the predation pressure exerted by birds and mice on snails. We found evidence of avian and mammalian predation in 26.5% and 36.8% of the shells. Both birds and mammals were selective with respect to snail species, size and morphs. Birds preferred the brown-lipped banded snail Cepaea nemoralis (L.) and mice preferred the burgundy snail Helix pomatia L. Mice avoided pink mid-banded C. nemoralis and preferred brown mid-banded morphs, which were neglected by birds. In contrast to mice, birds chose larger individuals. Significant differences in their predatory pressure can influence the evolution and maintenance of shell size and polymorphism of shell colouration in snails.

  5. Comparison of Cooling Different Parts in a High Pressure Ratio Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    S. Mostafa Moosania

    2016-12-01

    Full Text Available Cooling in a centrifugal compressor can improve the performance and reduce the impeller temperature. In a centrifugal compressor, external walls can be cool down, which is known as the shell cooling. This method avoids undesirable effects induced by other cooling methods. Cooling can be applied on different external walls, such as the shroud, diffuser or the back plate. This paper focuses on seeking the most effective cooling place to increase the performance and reduce the impeller temperature. It is found that shroud cooling improves the compressor performance the most. Shroud cooling with 2400 W of cooling power increases the pressure ratio by 4.6% and efficiency by 1.49%. Each 500 W increase in the shroud cooling power, increases the efficiency by 0.3%. Diffuser cooling and back plate cooling have an identical effect on the polytropic efficiency. However, back plate cooling increases the pressure ratio more than diffuser cooling. Furthermore, only back plate cooling reduces the impeller temperature, and with 2400 W of cooling power, the impeller temperature reduces by 45 K.

  6. 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

  7. 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.

  8. Arc discharge deposition of stainless steel coatings at different nitrogen pressures

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, J. [VTT Manufacturing Technology (Finland); Torri, P. [Helsinki Univ. (Finland). Dept. of Physics; Hirvonen, J.P. [VTT Manufacturing Technology (Finland); Mahiout, A. [VTT Manufacturing Technology (Finland); Stanishevsky, A. [Plasmoteg Engineering Centre, Minsk (Belarus)

    1996-03-01

    A filtered arc discharge process was employed to deposit stainless steel films using an AISI316 cathode. In this procedure, macroparticles and droplets, which are the most serious drawback of arc deposition processes especially in corrosion applications, are mostly filtered out. Films were deposited in vacuum or in the presence of a nitrogen plasma at different partial pressures. Low carbon steel and silicon single crystals were employed as substrates. Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA) and X-ray diffraction (XRD) were used to characterize the films. The corrosion properties were examined using electrochemical polarization measurements. The corrosion current density was clearly lower than that of bulk steel, but higher than that of bulk AISI316. Increasing the film thickness and nitrogen content lowered the corrosion current density. (orig.)

  9. 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.

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

    Science.gov (United States)

    Garcia-Jares, Carmen; Vazquez, Alberto; Lamas, Juan P; Pajaro, Marta; Alvarez-Casas, Marta; Lores, Marta

    2015-11-19

    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.

  11. 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

    To a large extent population blood pressure (PBP) affects morbidity and mortality in the society. Reports indicated that PBP decreased in many western countries. The associations between the main cardiovascular risk factors and the changing PBP have been described. The aim of this study....... In addition, there was a trend towards a lowering of risk-factor adjusted SBP in the high income women with time. The mechanism that lies behind the associations between trend in SBP and income is not known but data suggest that poor lifestyle may explain some of the differences. The treated hypertensives...... was to investigate association between income factors and trends in population BP and hypertension. Copenhagen City Heart Study is a prospective longitudinal epidemiological study on almost 20000 individuals through four surveys from 1976 to 2003. The BP measurement was fully standardised. Questionnaires...

  12. 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 individuals not taking antihypertensive treatment from 13...... 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...... was significantly higher than the corresponding conventional BP (6.0, 5.2, and 4.7 mm Hg for systolic; 2.5, 2.7, and 1.7 mm Hg for diastolic BP; all Pindividuals aged 60 to 70 and ≥70 years, conventional BP was significantly higher than daytime ambulatory BP (5.0 and 13.0 mm Hg for systolic; 2.0 and 4...

  13. 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

    The skin perfusion pressure (SPP) measured as the isotope washout cessation external pressure is valuable in selection of major amputation level. Five methodological investigations important to clinical use were carried out: (1) In five normal legs and 10 legs with arterial occlusive disease (AOD...... 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...... pressure in seven patients (12 legs with AOD), the segmental SPP and the segmental systolic blood pressure were found on average to vary in proportion with intra-arterial mean and systolic pressure respectively; however, this proportional relationship was not valid for the individual leg. It is concluded...

  14. 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.

  15. 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

  16. Is there a possibility of ranking benthic quality assessment indices to select the most responsive to different human pressures?

    Science.gov (United States)

    Borja, Ángel; Marín, Sandra L; Muxika, Iñigo; Pino, Loreto; Rodríguez, José G

    2015-08-15

    Although a plethora of benthic indices exist, there is no agreement on what index or indices should be used by environmental managers to establish benthic quality. The objective of this investigation was to rank 35 benthic quality assessment indices used in different countries to evaluate the impact produced by 15 different human pressures (including multipressure, aquaculture, sewage discharges, eutrophication, physical alteration, chemical pollution, climate change, etc.). The ranking was determined by taking into account the coverage area of biogeographical provinces, number of citations testing a pressure and number of citations with significant correlation with pressure. We analysed 363 references, of which 169 showed quantitative data. Over a potential total score of 100, the highest values were obtained by the following indices: (i) AZTI's Marine Biotic Index (AMBI), which scored 77, tested by using 14 pressures in 14 provinces from the Arctic to tropical seas; (ii) multivariate AMBI (M-AMBI), which scored 74, tested with 12 pressures in 13 provinces; (iii) Bentix (BENTIX), which scored 68, tested with nine pressures in six provinces; (iv) Benthic Quality Index (BQI), which scored 66, tested with five pressures in seven provinces; and (v) Benthic Opportunistic Polychaetes Amphipods (BOPA) index, which scored 62, tested with eight pressures in six provinces.

  17. 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

  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

    digit (strain gauge technique). The two different methods correlated statistically significant at all four levels, but the systolic blood pressures were higher than the SPP in particular in diabetic legs; (3) Angiograms in 35 legs with AOD showed that the SPP on the ankle was only consistently decreased......The skin perfusion pressure (SPP) measured as the isotope washout cessation external pressure is valuable in selection of major amputation level. Five methodological investigations important to clinical use were carried out: (1) In five normal legs and 10 legs with arterial occlusive disease (AOD......Hg (range 18-98) (P less than 0.02). The average washout constant for the three different tracers were approximately equal and correlated statistically significant with the SPP; (2) In 59 legs with AOD, segmental SPP was compared to segmental systolic blood pressures on the thigh, calf, ankle and first...

  19. Laboratory measurement of longitudinal wave velocity of artificial gas hydrate under different temperatures and pressures

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The longitudinal wave velocity and attenuation measurements of artificial gas hy- drate samples at a low temperature are reported. And the temperature and pressure dependence of longitudinal wave velocity is also investigated. In order to under- stand the acoustic properties of gas hydrate, the pure ice, the pure tetrahydrofuran (THF), the pure gas hydrate samples and sand sediment containing gas hydrate are measured at a low temperature between 0℃ and –15℃. For the pure ice, the pure THF and the pure gas hydrate samples, whose density is 898 kg/m3, 895 kg/m3 and 475 kg/m3, the velocity of longitudinal wave is respectively 3574 m/s, 3428 m/s and 2439 m/s. For synthesized and compacted samples, the velocity of synthesized samples is lower than that of compacted samples. The velocities increase when the densities of the samples increase, while the attenuation decreases. Under the con- dition of low temperature, the results show that the velocity is slightly affected by the temperature. The results also show that wave velocities increase with the in- crease of piston pressures. For example, the velocity of one sample increases from 3049 up to 3337 m/s and the other increases from 2315 up to 2995 m/s. But wave velocity decreases from 3800 to 3546 m/s when the temperature increases from –15℃ to 5℃ and changes significantly close to the melting point. Formation con- ditions of the two samples are the same but with different conversion ratios of wa- ter. The results of the experiment are important for exploration of the gas hydrate resources and development of acoustic techniques.

  20. Complex positive selection pressures drive the evolution of HIV-1 with different co-receptor tropisms

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    HIV-1 co-receptor tropism is central for understanding the transmission and pathogenesis of HIV-1 infection. We performed a genome-wide comparison between the adaptive evolution of R5 and X4 variants from HIV-1 subtypes B and C. The results showed that R5 and X4 variants experienced differential evolutionary patterns and different HIV-1 genes encountered various positive selection pressures, suggesting that complex selection pressures are driving HIV-1 evolution. Compared with other hypervariable regions of Gp120, significantly more positively selected sites were detected in the V3 region of subtype B X4 variants, V2 region of subtype B R5 variants, and V1 and V4 regions of subtype C X4 variants, indicating an association of positive selection with co-receptor recognition/binding. Intriguingly, a significantly higher proportion (33.3% and 55.6%, P<0.05) of positively selected sites were identified in the C3 region than other conserved regions of Gp120 in all the analyzed HIV-1 variants, indicating that the C3 region might be more important to HIV-1 adaptation than previously thought. Approximately half of the positively selected sites identified in the env gene were identical between R5 and X4 variants. There were three common positively selected sites (96, 113 and 281) identified in Gp41 of all X4 and R5 variants from subtypes B and C. These sites might not only suggest a functional importance in viral survival and adaptation, but also imply a potential cross-immunogenicity between HIV-1 R5 and X4 variants, which has important implications for AIDS vaccine development.

  1. 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.

  2. Membrane associated qualitative differences in cell ultrastructure of chemically and high pressure cryofixed plant cells.

    Science.gov (United States)

    Zechmann, Bernd; Müller, Maria; Zellnig, Günther

    2007-06-01

    Membrane contrast can sometimes be poor in biological samples after high pressure freezing (HPF) and freeze substitution (FS). The addition of water to the FS-medium has been shown to improve membrane contrast in animal tissue and yeast. In the present study we tested the effects of 1% and 5% water added to the FS-medium (2% osmium with 0.2% uranyl acetate in anhydrous acetone) on the quality and visibility of membranes in high pressure frozen leaf samples of Cucurbita pepo L. plants and compared them to chemically fixed cells (3% glutaraldehyde post-fixed with 1% osmium tetroxide). The addition of water to the FS-medium drastically decreased the amounts of well preserved cells and did not significantly improve the quality nor visibility of membranes. In samples that were freeze substituted in FS-media containing 1% and 5% water the width of thylakoid membranes was found to be significantly increased of about 20% and the perinuclear space was up to 76% wider in comparison to what was found in samples which were freeze substituted without water. No differences were found in the thickness of membranes between chemically and cryofixed cells that were freeze substituted in the FS-medium without water. Nevertheless, in chemically fixed cells the intrathylakoidal space was about 120% wider than in cryofixed cells that were freeze substituted with or without water. The present results demonstrate that the addition of water to the FS-medium does not improve membrane contrast but changes the width of thylakoid membranes and the perinuclear space in the present plant material. The addition of water to the FS-medium is therefore not as essential for improved membrane contrast in the investigated plant samples as it was observed in cells of animal tissues and yeast cells.

  3. Intraoral air pressure and oral air flow under different bleed and bite-block conditions.

    Science.gov (United States)

    Putnam, A H; Shelton, R L; Kastner, C U

    1986-03-01

    Intraoral pressures and oral flows were measured as normal talkers produced /p lambda/ and /si/ under experimental conditions that perturbed the usual aeromechanical production characteristics of the consonants. A translabial pressure-release device was used to bleed off intraoral pressure during /p/. Bite-blocks were used to open the anterior bite artificially during /s/. For /p/, intraoral pressure decreased and translabial air leakage increased as bleed orifice area increased. For /s/, flow increased as the area of sibilant constriction increased, but differential pressure across the /s/ oral constriction did not vary systematically with changes in its area. Flow on postconsonantal vowels /lambda/ and /i/ did not vary systematically across experimental conditions. The data imply that maintenance of perturbed intraoral pressure was more effective when compensatory options included opportunity for increased respiratory drive and structural adjustments at the place of consonant articulation rather than increased respiratory drive alone.

  4. 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.

  5. Ethnic differences in insulinemia and sympathetic tone as links between obesity and blood pressure.

    Science.gov (United States)

    Weyer, C; Pratley, R E; Snitker, S; Spraul, M; Ravussin, E; Tataranni, P A

    2000-10-01

    Hyperinsulinemia and increased sympathetic nervous system (SNS) activity are thought to be pathophysiological links between obesity and hypertension. In the present study, we examined the relation among heart rate (HR), blood pressure (BP), and percent body fat (hydrodensitometry or DEXA), fasting plasma insulin concentration, and muscle sympathetic nerve activity (MSNA, microneurography) in male, normotensive whites (n=42) and Pima Indians (n=77). Pima Indians have a high prevalence of obesity and hyperinsulinemia but a relatively low prevalence of hypertension. Compared with whites, Pima Indian men had a higher percent body fat (28% versus 21%) and higher fasting insulin concentrations (210 versus 132 pmol/L) but lower MSNA (27 versus 33 bursts/min) (all P<0.001). In both ethnic groups, HR and BP were positively related to percent body fat and MSNA, and both were significant independent determinants of HR and BP in multiple regression analyses. However, MSNA was positively related to percent body fat and the fasting insulin concentration in whites (r=0.60 and r=0.47, both P<0.01) but not in Pima Indians (r=0.15 and r=0.03, NS) (P<0.01 for ethnic differences in the slope of the regression lines). These results confirm the physiological importance of the SNS in normal BP regulation but indicate that the roles of hyperinsulinemia and increased SNS activity as mediators for the relation between obesity and hypertension can differ between different ethnic groups. The lack of an increase in SNS activity with increasing adiposity and insulinemia in Pima Indians may contribute to the low prevalence of hypertension in this population.

  6. The Effect of Carbon Dioxide Insufflation Applied at Different Pressures and Periods on Thrombotic Factors.

    Science.gov (United States)

    Sen, Mehmet Celal; Turkyilmaz, Zafer; Sonmez, Kaan; Karabulut, Ramazan; Kaya, Zuhre; Yenicesu, Idil; Gursel, Turkiz; Basaklar, Abdullah Can

    2016-03-01

    The aim of this experimantal study which is applied on rats, is to determine the differences on the clotting factors over the application of low and high intraabdominal pressure (IAP) values in different periods of time in carbon dioxide (CO2) pneumoperitoneum. Thirty rats were randomized into five groups (n = 6): a control group (Group K) and 1 h and 6 mm Hg IAP (Group A), 2 h and 6 mm Hg IAP (Group B), 1 h and 12 mm Hg IAP (Group C) and 2 h and 12 mm Hg IAP were created with CO2 pneumoperitoneum (Group D). At the end of the experiment, plasma samples taken from subjects and fibrinogen, FII (prothrombin), FV, FVII, FVIII, FIX, FX, FXI, FXII, von willebrand's factor (vWF), ristocetin cofactor, protein C, protein S, antithrombin III (AT III) levels are studied. There were statistically significant differences in the mean levels of FII, FV, FVII, FVIII, FIX, FX, FXI, FXII, and protein S between the groups. A hypercoagulable state occurred with the following: increase in the coagulation parameters compared to the control group; increase in FVII in the group only Group C; decrease in AT III in all groups compared to the control group; decrease in protein C in the group only XII Group D compared to control group; decrease in protein S in all groups except group D compared to control group. CO2 insufflation predisposes to thromboembolic events both by inducing coagulation factors and by suppressing the fibrinolytic system contrary to the controversies in the literature.

  7. 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.

    2008-01-01

    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…

  8. 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 The effect of pressure on the structure and composition of silicon nanoparticles synthesized by hot wire thermal catalytic pyrolysis (HW-TCP) of pure silane has been investigated. Light brown powders were produced at silane pressures of 10 and 50...

  9. The discharge of fine silica sand in a silo under different ambient air pressures

    Science.gov (United States)

    Hsiau, Shu-San; Liao, Chun-Chung; Lee, Jie-Hsien

    2012-04-01

    Silos are widely used for the industrial scale handling and transportation of powdered and granular materials. The process of discharging powder in a silo involves the flow of both solid particles and an interstitial fluid, usually air. In this study, we experimentally investigate the effects of particle size and ambient pressure on the discharge process in open- and closed-top silos. The discharge rate, pressure drop, and pressure recovery rate are measured and discussed. The results show that the particle size, the diameter of the orifice, and the ambient pressure significantly influence the process of discharge. The effect of air flow is stronger on fine-powdered flow in a closed-top silo. The results indicate that the effects of air flow could be reduced by lowering the ambient pressure. In addition, a normalized critical pressure can be defined beyond which the discharge rate increases dramatically. With reduced ambient pressure, this normalized critical pressure decreases with increasing particle size. Finally, the experimental results are compared with results calculated using the Beverloo equation and Darcy's law.

  10. Heat Transfer in Film Boiling from Electrically Heated Nichrome Wire to Boiling Water at Different Pressure-II

    Directory of Open Access Journals (Sweden)

    Devi Dayal

    1969-01-01

    Full Text Available Values of film thickness in film boiling have been computed for three different sizes of nichrome wires at five different sub-atmospheric pressures. The values of alpha , total heat transmission co-efficient, ac heat transmission co-efficient due to conduction through the vapour film and alpha R, heat transmission co-efficient due to radiation, have been calculated. The values of film thickness were found to decrease with external pressure, but were found to increase slightly with the radius of the wire. alpha & alpha c both increase with rise of pressure but decrease with the radius of the radius of the heated wire. Alpha R shows a minimum value at a pressure of 15 cm. of Hg. in the case of all the wire sizes. The radiation loss alpha R is much smaller than conduction loss alpha. "

  11. 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.

  12. Influence of different artificial lighting regimes on intraocular pressure circadian profile in the dog (Canis familiaris).

    Science.gov (United States)

    Piccione, Giuseppe; Giannetto, Claudia; Fazio, Francesco; Giudice, Elisabetta

    2010-01-01

    The present study was undertaken to determine the temporal variation in intraocular pressure (IOP) and if this variation is under circadian clock control. The authors exposed five female and five male Beagles to four different artificial lighting regimes: 12/12 light/dark (L/D) period, 12/12 D/L period, constant light, and constant darkness. IOP was measured at 3 h intervals over a 48-h period. Statistical analysis of the data was performed by multivariate ANOVA, one-way repeated measure ANOVA and by the single cosinor method. Results showed no statistical effect of gender, eye and photoperiod on IOP values. A significant effect of time for each gender and each eye during all lighting regimes was seen, except during constant light, and also robust daily rhythmicity of IOP values in all L/D periods, except during constant light. In conclusion IOP values in the dog show a circadian rhythm and this rhythm is driven by a central pacemaker.

  13. Blood pressure differences in people with various individual characteristics in Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    麦劲壮; 饶栩栩; 刘小清

    2001-01-01

    Objective To study the differences in blood pressure (BP)levels and the main factors raising BP among the population in Guangdong province.Methods The data analyzed stem from the sampling survey of hypertension in Guangdong Province in 1991,covering 42,894 subjects over 15 years old.Individual characteristics included age,sex,occupation education,smoking,alcohol drinking and body mass indx(BMI).Results Systolic and diastolic BP increased with age.The hypertension prevalence rate in male is higher than in female.The age-adjusted prevalence rate in office personnel is the highest(12.9%)among all occupations.It was increased with educfation level and BMI (in people educated atuniversity and over is 13.1%),and higher in smokers and alcohol-drinkers than non -smokers and nonalcohol-drinkers.Conclusions Age,occupation,education,smoking,alcohol drinking and BMI all effect BP.These risk factors should be reduced in the Guangdong population.

  14. 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 measurement results, we inferred that the difference in the CoP positions between the two different groups could be attributed to the difference in the hip positions. Most skilled experts position their hips in such a way that their CoP trajectories move toward the opposite side during left asymmetric lifting. Although the skillful characteristics of experts may be responsible for the lightening of the burden on the waist during asymmetric

  15. Sex Differences in Peripheral Augmentation Index and Arterial Reservoir Pressure during Upper Limb Postural Shifts

    Directory of Open Access Journals (Sweden)

    Kevin S. Heffernan

    2014-01-01

    Full Text Available We examined the peripheral hemodynamic response to passive arm postural changes in young men and women. Radial artery pulse waveforms were captured using applanation tonometry in 20 men (age 27 ± 2 yrs, BMI 25 ± 1 kg/m2 and 20 women (age 27 ± 2 yrs, BMI 23±1 kg/m2. Arm position was maintained at either heart level or supported 14 cm above/below heart level in a randomized fashion. Systolic augmentation index (sAIx and diastolic augmentation index (dAIx were used as estimates of pressure from wave reflections arriving in systole and diastole, respectively. A novel reservoir-wave separation technique was used to obtain arterial reservoir pressure (pressure generated by arterial capacitance. Women showed a significant reduction in radial diastolic pressure-time integral (DPTI (P0.05 or dAIx (P>0.05 when moving the arm from below to above heart level. Conversely, men showed an attenuated change in radial DPTI (P>0.05 concomitant with significant increases in reservoir pressure (P<0.05, sAIx (P<0.05, and dAIx (P<0.05. Gravity-mediated changes in regional hemodynamics produced by passive arm postural shifts are sex specific. Men demonstrate less change in regional diastolic pressure concomitant with increased augmentation index and arterial reservoir pressure.

  16. Analysis of changes in reflectance measurements on biological tissues subjected to different probe pressures.

    Science.gov (United States)

    Reif, Roberto; Amorosino, Mark S; Calabro, Katherine W; A'Amar, Ousama; Singh, Satish K; Bigio, Irving J

    2008-01-01

    Spectral reflectance measurements of biological tissues have been studied for early diagnoses of several pathologies such as cancer. These measurements are often performed with a fiber optic probe in contact with the tissue surface. We report a study in which reflectance measurements are obtained in vivo from mouse thigh muscle while varying the contact pressure of the fiber optic probe. It is determined that the probe pressure is a variable that affects the local optical properties of the tissue. The reflectance spectra are analyzed with an analytical model that extracts the tissue optical properties and facilitates the understanding of underlying physiological changes induced by the probe pressure.

  17. Blood pressure differences between office and home settings among Japanese normotensive subjects and hypertensive patients.

    Science.gov (United States)

    Mori, Hisao; Ukai, Hiroshi; Yamamoto, Hareaki; Yuasa, Shouhei; Suzuki, Yoshiro; Chin, Keiichi; Katsumata, Takuma; Umemura, Satoshi

    2016-10-06

    This study attempted to clarify the differences in blood pressure (BP) between the office (clinic) and home settings in patients with controlled, sustained, masked or white-coat hypertension. The following formula was used: office mean systolic BP (omSBP)-mean morning home SBP (mmhSBP)/office mean diastolic BP (omDBP)-mean morning home DBP (mmhDBP). The paired t-test was used for statistical analysis. The omSBP-mmhSBP/omDBP-mmhDBP calculation yielded the following results: among normotensive subjects, -1.1±11.2/-1.7±8.5 mm Hg (mean SBP and mean DBP were higher at home than in the office; n=451, P=0.038 in SBP, P=0.000 in DBP); in controlled hypertensive patients, -0.42±10.9/-2.2±8.2 mm Hg (n=1362, P=0.160 in SBP, P=0.000 in DBP); among sustained hypertensive patients, 5.6±14.7/0.048±9.9 mm Hg (n=1370, P=0.000 in SBP, P=0.857 in DBP); in masked hypertensive patients, -15.3±12.9/-9.3±9.5 mm Hg (n=1308, both P=0.000); and among white-coat hypertensive patients, 23.7±13.2/8.2±9.1 mm Hg (n=580, both P=0.000). Our results showed a difference of 5 mm Hg in SBP among sustained hypertensive patients, as recommended by the Japanese Society of Hypertension Guidelines for the Management of Hypertension; however, in other hypertensive patient types, the differences in SBP and DBP between office and home measurements differed by >5 mm Hg. Office and home BP measurements should be interpreted cautiously, keeping in mind the clinical setting.Hypertension Research advance online publication, 6 October 2016; doi:10.1038/hr.2016.125.

  18. Plantar Pressure Distribution among Older Persons with Different Types of Foot and Its Correlation with Functional Reach Distance

    Directory of Open Access Journals (Sweden)

    Aisyah Mohd Said

    2016-01-01

    Full Text Available Background. Changes in biomechanical structures of human foot are common in the older person, which may lead to alteration of foot type and plantar pressure distribution. We aimed to examine how foot type affects the plantar pressure distribution and to determine the relationship between plantar pressure distribution and functional reach distance in older persons. Methods. Fifty community-dwelling older persons (age: 69.98±5.84 were categorized into three groups based on the Foot Posture Index. The plantar pressure (max⁡P and contact area were analyzed using Footscan® RSScan platform. The Kruskal-Wallis test was used to compare the plantar pressure between foot types and Spearman’s correlation coefficient was used to correlate plantar pressure with the functional reach distance. Results. There were significant differences of max⁡P in the forefoot area across all foot types. The post hoc analysis found significantly lower max⁡P in the pronated foot compared to the supinated foot. A high linear rank correlation was found between functional reach distance and max⁡P of the rearfoot region of the supinated foot. Conclusions. These findings suggested that types of the foot affect the plantar maximal pressure in older persons with functional reach distance showing some associations.

  19. A comparative analysis of young tennis player target accuracy when using balls inflated under different pressures

    Directory of Open Access Journals (Sweden)

    Dmytro Krylov

    2017-06-01

    Full Text Available Purpose: make a comparative analysis of the target accuracy of ten-year tennis players in performing test exercises with balls with a pressure of 75% of the standard and balls with standard pressure. Material & Methods: in the study participated 8 tennis players of ten years of age, the group 5 years of training. In the course of the research, the following methods were used: analysis and generalization of literature sources, analysis of documentary materials, testing, method of expert evaluations. Results: replacing balls with a pressure of 75% of the standard for standard leads to a deterioration in the target accuracy of ten-year tennis players, which is a consequence of distortion of the technical characteristics of movements. Conclusion: results of the study indicate the need for correction of the technique of players of this age in the transition from balls with a pressure of 75% from the standard to standard.

  20. Simultaneous laser induced breakdown spectroscopy and Pd-assisted methane decomposition at different pressures

    Energy Technology Data Exchange (ETDEWEB)

    Reyhani, A. [Phys. Dept., Faculty of Science, Imam Khomeini International University, Qazvin, 34149-16818 (Iran, Islamic Republic of); Mortazavi, S.Z. [Phys. Dept., Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Parvin, P., E-mail: parvin@aut.ac.ir [Phys. Dept., Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Mahmoudi, Z. [Phys. Dept., Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)

    2012-08-15

    Methane decomposition is investigated during Pd-assisted laser induced plasma in the controlled chamber at various pressures using Q-switched Nd:YAG laser. Real time LIBS monitoring is applied to reveal the involved mechanisms during methane decomposition by inspecting the plasma parameters at mano-metric pressures of 1 to 10 mbar. The dependence of electron density and plasma temperature with pressure is also studied. It is shown that the plasma recreates higher hydrocarbons during the decomposition of methane. In addition, Fourier transform infrared spectroscopy, gas chromatography, scanning electron microscopy and transmission electron microscopy are applied to support the findings. - Highlights: Black-Right-Pointing-Pointer Simultaneous laser induced breakdown spectroscopy Black-Right-Pointing-Pointer Pd-assisted methane decomposition Black-Right-Pointing-Pointer Nanosecond pulsed laser decomposition of methane Black-Right-Pointing-Pointer Generation of higher hydrocarbon Black-Right-Pointing-Pointer Dependence of electron density and temperature of induced plasma with pressure.

  1. 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.

  2. 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.

  3. 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.

  4. Thermal and structural alternations in CuAlMnNi shape memory alloy by the effect of different pressure applications

    Science.gov (United States)

    Canbay, Canan Aksu; Polat, Tercan

    2017-09-01

    In this work the effects of the applied pressure on the characteristic transformation temperatures, the high temperature order-disorder phase transitions, the variation in diffraction peaks and the surface morphology of the CuAlMnNi shape memory alloy was investigated. The evolution of the transformation temperatures was studied by differential scanning calorimetry (DSC) with different heating and cooling rates. The differential thermal analysis measurements were performed to obtain the ordered-disordered phase transformations from room temperature to 900 °C. The characteristic transformation temperatures and the thermodynamic parameters were highly sensitive to variations in the applied pressure and also the applied pressure affected the thermodynamic parameters. The activation energy of the sample according to applied pressure values calculated by Kissinger method. The structural changes of the samples were studied by X-ray diffraction (XRD) measurements and by optical microscope observations at room temperature.

  5. Pulse pressure variation and stroke volume variation under different inhaled concentrations of isoflurane, sevoflurane and desflurane in pigs undergoing hemorrhage

    Directory of Open Access Journals (Sweden)

    Alexandre Hideaki Oshiro

    2015-12-01

    Full Text Available OBJECTIVES: Inhalant anesthesia induces dose-dependent cardiovascular depression, but whether fluid responsiveness is differentially influenced by the inhalant agent and plasma volemia remains unknown. The aim of this study was to compare the effects of isoflurane, sevoflurane and desflurane on pulse pressure variation and stroke volume variation in pigs undergoing hemorrhage. METHODS: Twenty-five pigs were randomly anesthetized with isoflurane, sevoflurane or desflurane. Hemodynamic and echocardiographic data were registered sequentially at minimum alveolar concentrations of 1.00 (M1, 1.25 (M2, and 1.00 (M3. Then, following withdrawal of 30% of the estimated blood volume, these data were registered at a minimum alveolar concentrations of 1.00 (M4 and 1.25 (M5. RESULTS: The minimum alveolar concentration increase from 1.00 to 1.25 (M2 decreased the cardiac index and increased the central venous pressure, but only modest changes in mean arterial pressure, pulse pressure variation and stroke volume variation were observed in all groups from M1 to M2. A significant decrease in mean arterial pressure was only observed with desflurane. Following blood loss (M4, pulse pressure variation, stroke volume variation and central venous pressure increased (p <0.001 and mean arterial pressure decreased in all groups. Under hypovolemia, the cardiac index decreased with the increase of anesthesia depth in a similar manner in all groups. CONCLUSION: The effects of desflurane, sevoflurane and isoflurane on pulse pressure variation and stroke volume variation were not different during normovolemia or hypovolemia.

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

    Science.gov (United States)

    Desmazières, Bernard; Legros, Véronique; Giuliani, Alexandre; Buchmann, William

    2014-01-15

    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 8eV up to 10.6eV 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 ionization energy of the solvent. As commercial APPI sources typically use krypton lamps with energy fixed at 10eV and 10.6eV, the study of the ionization of polymers over a wavelength range allowed to confirm and refine the previously proposed ionization mechanisms. Moreover, the APPI source can efficiently be used as an interface between size exclusion chromatography or reverse phase liquid chromatography and MS for the study of synthetic oligomers. However, the photoionization at fixed wavelength of polymer standards with different molecular weights showed that it was difficult to obtain intact ionized oligomers with molecular weights above a few thousands.

  7. Differences in Topographical Pressure Pain Sensitivity Maps of the Scalp Between Patients With Migraine and Healthy Controls.

    Science.gov (United States)

    Barón, Johanna; Ruiz, Marina; Palacios-Ceña, María; Madeleine, Pascal; Guerrero, Ángel L; Arendt-Nielsen, Lars; Fernández-de-Las-Peñas, César

    2017-02-01

    To investigate differences in topographical pressure pain sensitivity maps of the scalp between patients with migraine and healthy controls considering the chronicity (episodic/chronic) and side (strictly unilateral/bilateral) of the symptoms. It seems that the trigeminal area is sensitized in migraine. No study has investigated topographical pressure sensitivity maps of the scalp in patients with migraine. Pressure pain thresholds (PPTs) were assessed from 21 points distributed over the scalp in 86 patients with episodic migraine, 76 with chronic migraine, and 42 healthy age and matched healthy controls in a blinded design. Topographical pressure pain sensitivity maps based on interpolation of the PPTs were constructed. Clinical features of migraine, anxiety, and depression (Hospital Anxiety and Depression Scale, HADS) were collected. The multivariate ANCOVA revealed significant differences in PPT between points (F = 55.674; P  .335) except for Fp1 (P = .045) and Fp2 (P = .017) points where subjects with chronic migraine had lower PPTs than those with episodic migraine; (3) no differences between bilateral/unilateral migraine (P > .417). An anterior to posterior gradient was found, with the lowest PPTs located in frontal regions and the highest PPTs in occipital areas (all groups, P pressure pain hypersensitivity in the head as compared to healthy controls and that hypersensitivity was similar between episodic/chronic and unilateral/bilateral migraine. Topographical pressure pain sensitivity maps revealed an anterior to posterior gradient of pressure pain sensitivity in both migraine and control groups. © 2016 American Headache Society.

  8. 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.

  9. The interplay of parental support, parental pressure and test anxiety--Gender differences in adolescents.

    Science.gov (United States)

    Ringeisen, Tobias; Raufelder, Diana

    2015-12-01

    This study examined gender-specific relationships between adolescents' perceptions of school-related support/pressure from their parents and test anxiety. A sample of German students (N = 845; Mage = 15.32; SD = .49) completed questionnaires that measured their perceived parental support/pressure (for mother and father separately) as well as the four main components of test anxiety (worry, interference, lack of confidence, and emotionality). Gender-specific relations were identified using multigroup structural equation modeling: For girls, perceived maternal pressure was positively associated with emotionality and interference; for boys, perceived father pressure and father support were positively associated with interference and worry, respectively. For both genders, perceived mother pressure and support were related to lack of confidence. Our findings suggest that adolescents' perceptions of maternal attitudes are associated with students' self-confidence irrespective of the child's gender, whereas the remaining facets of test anxiety follow same-sex trajectories between perceived parental attitudes and adolescents' test anxiety.

  10. First principles investigation of magnesium antimonite semiconductor compound in two different phases under hydrostatic pressure

    Science.gov (United States)

    Sedighi, Matin; Nia, Borhan Arghavani; Zarringhalam, Hanif; Moradian, Rostam

    2011-09-01

    We investigate the electronic and the structural properties of Mg 3Sb 2 in cubic and hexagonal phases using the full potential-linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory. The effects of hydrostatic pressure on band gap, bandwidths of bands under Fermi energy labeled by B1 and B2 from the top, the energy gap between B1 and B2 (anti-symmetry gap) and also effective masses of electrons and holes are studied using optimized lattice parameters. We observe that the hydrostatic pressure decreases the band gap and the anti-symmetry gap while it increases the bandwidths of all bands below the Fermi energy. The effective masses of electrons and holes for the hexagonal phase depend on pressure in the Γ→ Λ direction. In the cubic phase the effective mass of electrons is independent of pressure and the effective mass of holes depend on the pressure in the Γ→ N direction.

  11. Effect of purity on adsorption capacities of a Mars-like clay mineral at different pressures

    Science.gov (United States)

    Jenkins, Traci; Mcdoniel, Bridgett; Bustin, Roberta; Allton, Judith H.

    1992-01-01

    There has been considerable interest in adsorption of carbon dioxide on Marslike clay minerals. Some estimates of the carbon dioxide reservoir capacity of the martian regolith were calculated from the amount of carbon dioxide adsorbed on the ironrich smectite nontronite under martian conditions. The adsorption capacity of pure nontronite could place upper limits on the regolith carbon dioxide reservoir, both at present martian atmospheric pressure and at the postulated higher pressures required to permit liquid water on the surface. Adsorption of carbon dioxide on a Clay Mineral Society standard containing nontronite was studied over a wide range of pressures in the absence of water. Similar experiments were conducted on the pure nontronite extracted from the natural sample. Heating curves were obtained to help characterize and determine the purity of the clay sample.

  12. Silicon microcantilevers with different actuation-readout schemes for absolute pressure measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bianco, S; Cocuzza, M; Ferrante, I; Giuri, E; Pirri, C F; Ricci, A; Scaltrito, L [Xlab - Materials and Microsystems Laboratory - Polytechnic of Turin, Latemar Unit Lungo Piazza D' Armi 6, 10034 Chivasso (Turin) (Italy); Bich, D; Merialdo, A; Schina, P [Olivetti I-Jet, Loc. Le Vieux, 11020 Arnad (Aosta) (Italy); Correale, R [Varian S.p.A., Via Fratelli Varian 54, 10040 Leini (Turin) Italy (Italy)], E-mail: matteo.cocuzza@infm.polito.it

    2008-03-01

    Silicon resonant microcantilevers for the measurement of the absolute pressure have been fabricated through micromachining processes. The first release is based on vertical resonant actuation and detection, both externally implemented, respectively through a piezoelectric actuator and an optical lever. The variation in resonance response was investigated as a function of pressure (10{sup -1} to 10{sup 5} Pa), both in terms of resonance frequency and quality factor. We demonstrated the feasibility of a miniaturized absolute pressure sensor working over a six decades range. The second release is based on lateral resonating microcantilevers in which a significative upgrade is represented by the miniaturization and integration of the actuator and the sensing directly on chip providing a more compact and potentially interesting solution for industrial vacuum applications. Actuation is performed with an electrostatic modulated force, while detection relies on a capacitive readout. Preliminary experiments are encouraging for the replication of the results obtained with the first version.

  13. Effects of different types of yam (Dioscorea alata) products on the blood pressure of spontaneously hypertensive rats.

    Science.gov (United States)

    Liu, Yuh-Hwa; Lin, Yin-Shiou; Liu, Der-Zen; Han, Chuan-Hsiao; Chen, Ching-Tan; Fan, Mike; Hou, Wen-Chi

    2009-06-01

    The aim of the present study was to investigate different yam treatments, including powdered-yam-products (PYP) and liquid-yam-products (LYP), with respect to spontaneously hypertensive rats (SHRs) blood pressure. PYP included alcohol-insoluble-solids of yam tuber, hot-air-drying (HAD) of yam tuber slices, steam-cooked once or twice followed by HAD which were subsequently powdered. LYP included water extracts of yam tuber (WEY) heated at 90 degrees C (WEY90H) or 95 degrees C for 10 min (WEY95H), and then stored at 4 degrees C for different numbers of day. PYP, WEY, and WEYH were found effectively to reduce the blood pressure of SHR and should be beneficial in food processing in the development of functional foods for blood pressure regulation.

  14. 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...... flows after breathing air,  20% oxygen in He and 20% oxygen in SF6 . For construction of MFSR-curves. Lung elastic recoil pressures were estimated  from ECCS reference values (Bull. europ. Physiopath. resp. 1983, 19  (suppl 5),28-31). The model described in the figure was used. The extrapolated flow FY...... 1, but certainly different from1.5, indicating predominant laminar flow upstream to CP. The upstream resistance is low, and lower than directly measured (JAP 83:1721-32,1997). This is a possibility if CP is more peripheral than assumed in that study.  ...

  15. Investigation of the level difference between sound pressure and sound intensity in an aircraft cabin under different fuselage conditions

    Science.gov (United States)

    Atwal, M. S.; Crocker, M. J.; Heitman, K. E.

    1985-01-01

    Problems in using two-microphone sound-intensity (SI) measurements to measure structural transmission losses are investigated in experiments involving light-aircraft fuselage panels and windows. Both sound pressure (SP) and SI are measured near the passenger and door windows and panels of a single-engine aircraft and with these barriers removed, and the effect of increasing interior acoustic absorption and blocking flanking transmission paths is also tested. The results are presented graphically, and the SP measurements are used to indicate frequency ranges in which the two-microphone technique significantly underestimates SI. It is inferred that flanking paths and interior reverberation must be effectively suppressed in order to obtain accurate transmission-loss measurements.

  16. Control of microvascular oxygen pressures in rat muscles comprised of different fibre types

    Science.gov (United States)

    McDonough, Paul; Behnke, Brad J; Padilla, Danielle J; Musch, Timothy I; Poole, David C

    2005-01-01

    In response to an elevated metabolic rate , increased microvascular blood–muscle O2 flux is the product of both augmented O2 delivery and fractional O2 extraction. Whole body and exercising limb measurements demonstrate that and fractional O2 extraction increase as linear and hyperbolic functions, respectively, of . Given the presence of disparate vascular control mechanisms among different muscle fibre types, we tested the hypothesis that, in response to muscle contractions, would be lower and fractional O2 extraction (as assessed via microvascular O2 pressure, PmvO2) higher in fast- versus slow-twitch muscles. Radiolabelled microsphere and phosphorescence quenching techniques were used to measure and PmvO2, respectively at rest and across the transition to 1 Hz twitch contractions at low (Lo, 2.5 V) and high intensities (Hi, 4.5 V) in rat (n = 20) soleus (Sol, slow-twitch, type I), mixed gastrocnemius (MG, fast-twitch, type IIa) and white gastrocnemius (WG, fast-twitch, type IIb) muscle. At rest and for Lo and Hi (steady-state values) transitions, PmvO2 was lower (all P < 0.05) in MG (mmHg: rest, 22.5 ± 1.0; Lo, 15.3 ± 1.3; Hi, 10.2 ± 1.6) and WG (mmHg: rest, 19.0 ± 1.3; Lo, 12.2 ± 1.1; Hi, 9.9 ± 1.1) than in Sol (rest, 33.1 ± 3.2 mmHg; Lo, 19.0 ± 2.3 mmHg; Hi, 18.7 ± 1.8 mmHg), despite lower and in MG and WG under each set of conditions. These data suggest that during submaximal metabolic rates, the relationship between and O2 extraction is dependent on fibre type (at least in the muscles studied herein), such that muscles comprised of fast-twitch fibres display a greater fractional O2 extraction (i.e. lower PmvO2) than their slow-twitch counterparts. These results also indicate that the greater sustained PmvO2 in Sol may be important for ensuring high blood–myocyte O2 flux and therefore a greater oxidative contribution to energetic requirements. PMID:15637098

  17. Relationship between blood pressure variability and different renal function impairment stages in elderly hypertension patients

    Institute of Scientific and Technical Information of China (English)

    王云

    2014-01-01

    Objective To observe the change of blood pressure variability(BPV)in elderly hypertension patients,and to analyze the correlation between BPV and stages of renal function damage.Methods 127 elderly primary hypertensive patients with chronic kidney disease(CKD)were divided into three groups:stage 2 CKD group(aged 60-

  18. Cavitation erosion of silver plated coating at different temperatures and pressures

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Shuji; Motoi, Yoshihiro [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fuku-shi, Fukui 910-8507 (Japan); Kikuta, Kengo; Tomaru, Hiroshi [IHI Corperation, TOYOSU IHI BUILDING, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 1358710 (Japan)

    2014-04-11

    Cavitation often occurs in inducer pumps used for space rockets. Silver plated coating on the inducer liner faces the damage of cavitation. Therefore, it is important to study about the cavitation erosion resistance for silver plated coating at several operating conditions in the inducer pumps. In this study, the cavitation erosion tests were carried for silver plated coating in deionized water and ethanol at several liquid temperatures (273K–400K) and pressures (0.10MPa–0.48MPa). The mass loss rate is evaluated in terms of thermodynamic parameter Σ proposed by Brennen [9], suppression pressure p–p{sub v} (p{sub v}: saturated vapor pressure) and acoustic impedance ρc (ρ: density and c: sound speed). Cavitation bubble behaviors depending on the thermodynamic effect and the liquid type were observed by high speed video camera. The mass loss rate is formulated by thermodynamic parameter Σ, suppression pressure p–p{sub v} and acoustic impedance ρc.

  19. 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

    Diesel spray experimentation at controlled high-temperature and high-pressure conditions is intended to provide a more fundamental understanding of diesel combustion than can be achieved in engine experiments. This level of understanding is needed to develop the high-fidelity multi-scale CFD mode...

  20. The Pressure of Misalignment Axions:a Difference from WIMPs in Galaxy Formation?

    OpenAIRE

    Davidson, Sacha

    2014-01-01

    Two populations of axions can contribute to cold dark matter: the classical field produced via the misalignment mechanism, and the modes produced in the decay of strings. The classical field has extra pressure, as compared to WIMPs, which could have observable consequences in non-linear galaxy formation.

  1. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study.

    Science.gov (United States)

    Chopra, Sakshi; Gupta, Narendra Kumar; Tandan, Amrit; Dwivedi, Ravi; Gupta, Swati; Agarwal, Garima

    2016-01-01

    Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. A significant difference in the pressure produced using different impression materials was found (P materials. The presence of relief did affect the magnitude of pressure at various locations. All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  2. Differences in topographical pressure pain sensitivity maps of the scalp between patients with migraine and healthy controls

    DEFF Research Database (Denmark)

    Barón, Johanna; Ruiz, Marina; Palacios-Ceña, María;

    2016-01-01

    OBJECTIVE: To investigate differences in topographical pressure pain sensitivity maps of the scalp between patients with migraine and healthy controls considering the chronicity (episodic/chronic) and side (strictly unilateral/bilateral) of the symptoms. BACKGROUND: It seems that the trigeminal a...

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

    NARCIS (Netherlands)

    Neuner, Irene; Kawohl, Wolfram; Arrubla, Jorge; Warbrick, Tracy; Hitz, Konrad; Wyss, Christine; Boers, Frank; Shah, N Jon

    2014-01-01

    INTRODUCTION: 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 (SPL

  4. Effect of different carbon sources on the biological phosphorus removal by a sequencing batch reactor using pressurized pure oxygen

    OpenAIRE

    Wei,Jie; IMAI, Tsuyoshi; Higuchi, Takaya; Arfarita, Novi; Yamamoto, Koichi; Sekine, Masahiko; Kanno, Ariyo

    2014-01-01

    The effect of different carbon source on the efficiency of enhanced biological phosphorus removal (EBPR) from synthetic wastewater with acetate and two ratios of acetate/starch as a carbon source was investigated. Three pressurized pure oxygen sequencing batch reactor (POSBR) experiments were operated. The reactors (POSBR1, POSBR2 and POSBR3) were developed and studied at different carbon source ratios of 100% acetate, 75% acetate plus 25% starch and 50% acetate plus 50% starch, respectively....

  5. 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.

  6. Predicting electrocardiogram and arterial blood pressure waveforms with different Echo State Network architectures.

    Science.gov (United States)

    Fong, Allan; Mittu, Ranjeev; Ratwani, Raj; Reggia, James

    2014-01-01

    Alarm fatigue caused by false alarms and alerts is an extremely important issue for the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the staff and hospital systems better classify a patient's waveforms and subsequent alarms. This paper explores the use of Echo State Networks, a specific type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure waveforms. Several network architectures are designed and evaluated. The results show the utility of these echo state networks, particularly ones with larger integrated reservoirs, for predicting electrocardiogram waveforms and the adaptability of such models across individuals. The work presented here offers a unique approach for understanding and predicting a patient's waveforms in order to potentially improve alarm generation. We conclude with a brief discussion of future extensions of this research.

  7. Studies of Breakdowns in Liquid Nitrogen at Different Pressures Between Rogowski Electrodes

    Science.gov (United States)

    Blaz, Michael; Kurrat, Michael

    The usage of superconducting machines in the power grid or other high energy application makes it necessary that the machine can withstand all electrical stresses which can occur during normal operation and at transient overload. To guarantee a sufficient insulation, it is essential to know the properties of the insulating material. For HTS applications liquid nitrogen is a possible cooling and insulation liquid. In this paper the influence of pressurized liquid nitrogen on the discharge voltage is observed. Therefore, a cryostat was used, that can be pressurized and the discharge voltages at 3 barabs and 5 barabs were investigated. The investigations were performed between Rogowski electrodes to guarantee a homogeneous electric field without discharges at the electrode edges. Experiments were done with gap distances up to 7 mm. The liquid nitrogen was stressed with lightning surge voltage of both polarities and AC ramp with a rise of 2000 V/s

  8. 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.

  9. 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.

  10. 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

    2015-01-01

    [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. PMID:26834348

  11. 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.

  12. The effect of intermittent intraabdominal pressure elevations and low cardiac output on the femoral to carotid arterial blood pressure difference in piglets.

    Science.gov (United States)

    Aksakal, Devrim; Hückstädt, Thomas; Richter, Steffen; Klitscher, Daniela; Wowra, Tobias; Schier, Felix; Wessel, Lucas M; Kubiak, Rainer

    2016-11-01

    Our previous work in a laparoscopic setting in piglets revealed that the systolic femoral artery pressure was approximately 5 % higher than its carotid counterpart, whereas the mean and diastolic values showed no significant difference. This remained idem when the intraabdominal pressure (IAP) was gradually increased. In this study, we aimed to investigate the effect of (1) intermittent IAP elevations and (2) a low cardiac output (CO) on the blood pressure (BP) difference cranially (carotid artery) and caudally (femoral artery) of a capnoperitoneum (ΔP = P a fem-P a carot). A total of twenty-two piglets (mean body weight 11.0 kg; range 8.9-13.3 kg) were studied. Of these, 14 underwent intermittent IAP elevations at 8 and 16 mmHg, and ΔP was measured. In another 8 piglets, a model of reduced CO was created by introducing an air embolism (2 ml/kg over 30 s) in the inferior caval vein (VCI) at 12 mmHg IAP to further assess the influence of this variable on ΔP. Systolic ΔP remained at a mean of 5.6 mmHg and was not significantly affected by insufflation or exsufflation up to an IAP of 16 mmHg. Diastolic and mean values showed no differences between P a carot and P a fem. P a fem, systol remained higher than its carotid counterpart as long as the cardiac index (CI) was above 1.5 l/min/m(2), but fell significantly below P a carot, systol at a low CI. There was no CO-dependent effect on diastolic and mean ΔP. Repeated IAP elevations do not significantly influence ΔP. Intermittent IAP elevations do not significantly influence ΔP. Despite of a CO-dependent inversion of systolic ΔP, mean BP measurements at the leg during laparoscopy remain representative even at low CO values.

  13. 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;

    2016-01-01

    Biering-Soerensen back extension test. RESULTS: 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 ... 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...

  14. The Effects of Different Insufflation Pressures on Liver Functions Assessed with LiMON on Patients Undergoing Laparoscopic Cholecystectomy

    Directory of Open Access Journals (Sweden)

    H. Barıs Eryılmaz

    2012-01-01

    Full Text Available Purpose. Laparoscopic cholecystectomy has been accepted as an alternative to laparotomy, but there is still controversy regarding the effects of pneumoperitoneum on splanchnic and hepatic perfusion. We assessed the effects of different insufflation pressures on liver functions by using indocyanine green elimination tests (ICG-PDR. Methods. We analyzed 43 patients who were scheduled for laparoscopic cholecystectomy. The patients were randomly allocated to two groups. In Group I, the operation was performed using 10 mmHg pressure pneumoperitoneum. In Group II, 14 mmHg pressure pneumoperitoneum was used. The ICG-PDR measurements were made after induction (ICG-PDR 1 and after the end of the operation (ICG-PDR 2. Serum aspartate aminotransferase (AST, alanine aminotransferase (ALT, and total bilirubin levels were all recorded preoperatively, 1 hour, and postoperative 24 hours after surgery. Results. The ICG-PDR 1 values for Groups I and II were as follows: 26.78±4.2% per min versus 26.01±2.4% per min (>0.05. ICG-PDR 2 values were found to be 25.63±2.1% per min in Group I versus 19.06±2.2% per min in Group II (0.05. Conclusion. In conclusion, the results show that 14 mmHg pressure pneumoperitoneum decreased the blood flow to the liver and increased postoperative 1st-hour serum AST and ALT levels. We think that 10 mmHg pressure pneumoperitoneum is superior to 14 mmHg pressure pneumoperitoneum in laparoscopic cholecystectomy.

  15. Pressure attenuation during high-frequency airway clearance therapy across different size endotracheal tubes: An in vitro study.

    Science.gov (United States)

    Smallwood, Craig D; Bullock, Kevin J; Gouldstone, Andrew

    2016-08-01

    High-frequency airway clearance therapy is a positive pressure secretion clearance modality used in pediatric and adult applications. However, pressure attenuation across different size endotracheal tubes (ETT) has not been adequately described. This study quantifies attenuation in an in vitro model. The MetaNeb® System was used to deliver high-frequency pressure pulses to 3.0, 4.0, 6.0 and 8.0mm ID ETTs connected to a test lung during mechanical ventilation. The experimental setup included a 3D-printed trachea model and imbedded pressure sensors. The pressure attenuation (Patt%) was calculated: Patt%=[(Pproximal-Pdistal)/Pproximal]x100. The effect of pulse frequency on Pdistal and Pproximal was quantified. Patt% was inversely and linearly related to ETT ID and (y=-7.924x+74.36; R(2)=0.9917, P=.0042 for 4.0Hz pulse frequency and y=-7.382+9.445, R(2)=0.9964, P=.0018 for 3.0Hz pulse frequency). Patt% across the 3.0, 4.0, 6.0 and 8.0mm I.D. ETTs was 48.88±10.25%, 40.87±5.22%, 27.97±5.29%, and 9.90±1.9% respectively. Selecting the 4.0Hz frequency mode demonstrated higher Pproximal and Pdistal compared to the 3.0Hz frequency mode (P=.0049 and P=.0065). Observed Pdistal was <30cmH2O for all experiments. In an in vitro model, pressure attenuation was linearly related to the inner diameter of the endotracheal tube; with decreasing attenuation as the ETT size increased. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. 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.

  17. Partially implicit finite difference scheme for calculating dynamic pressure in a terrain-following coordinate non-hydrostatic ocean model

    Science.gov (United States)

    Liu, Zhe; Lin, Lei; Xie, Lian; Gao, Huiwang

    2016-10-01

    To improve the efficiency of the terrain-following σ-coordinate non-hydrostatic ocean model, a partially implicit finite difference (PIFD) scheme is proposed. By using explicit terms instead of implicit terms to discretize the parts of the vertical dynamic pressure gradient derived from the σ-coordinate transformation, the coefficient matrix of the discrete Poisson equation that the dynamic pressure satisfies can be simplified from 15 diagonals to 7 diagonals. The PIFD scheme is shown to run stably when it is applied to simulate five benchmark cases, namely, a standing wave in a basin, a surface solitary wave, a lock-exchange problem, a periodic wave over a bar and a tidally induced internal wave. Compared with the conventional fully implicit finite difference (FIFD) scheme, the PIFD scheme produces simulation results of equivalent accuracy at only 40-60% of the computational cost. The PIFD scheme demonstrates strong applicability and can be easily implemented in σ-coordinate ocean models.

  18. 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.

  19. Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation

    Science.gov (United States)

    Yang, Hua; Jones, Michael; Shiota, Takahiro; Qin, Jian Xin; Kim, Yong Jin; Popovic, Zoran B.; Pu, Min; Greenberg, Neil L.; Cardon, Lisa A.; Eto, Yoko; Sitges, Marta; Zetts, Arthur D.; Thomas, James D.

    2002-01-01

    BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

  20. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study

    OpenAIRE

    Sakshi Chopra; Narendra Kumar Gupta; Amrit Tandan; Ravi Dwivedi; Swati Gupta; Garima Agarwal

    2016-01-01

    Introduction: Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secon...

  1. The different patterns of blood pressure elevation by rofecoxib and nabumetone.

    Science.gov (United States)

    Reitblat, T; Zamir, D; Estis, L; Priluk, R; Drogenikov, T; Viskoper, J R

    2002-06-01

    Hypertension and knee osteoarthritis (OA) are frequent comorbidities. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often used to relieve pain in such patients. In the last decade selective NSAIDs are used more commonly since they lead to less gastrointestinal complications. As has been shown, the treatment with NSAIDs may cause a mild rise of arterial blood pressure (BP). The influence of selective NSAIDs on BP, particularly in hypertensive patients has still to be investigated. The aim of this study was to determine arterial BP changes in patients suffering from stable arterial hypertension and knee OA and treated with rofecoxib or nabumetone. Two groups of patients with knee OA and stable arterial hypertension received either 25 mg rofecoxib once daily or namebutone 2000 mg once daily during the first week of treatment and 1000 mg for the following 3 weeks. Twenty-four hour arterial BP monitoring was performed prior to initiation of treatment and at the end of a 4-week period. The results were that no changes were found in the mean systolic and diastolic characteristics of BP in the rofecoxib treatment group during day time (delta systolic BP -0.4 mm Hg and delta diastolic BP -0.4 mm Hg), while nocturnal BP increased significantly: delta systolic BP +15.7 mm Hg and delta diastolic BP +8.5 mm Hg. The mean systolic arterial pressure in the nabumeton group raised delta systolic BP 2.9 mm Hg in the daytime and 5 mm Hg during the night-time after the treatment. The mean diastolic arterial pressure also rose delta diastolic 3.2 mm Hg and 4.9 mm Hg at day and night hours respectively. In conclusion rofecoxib treatment did not change arterial BP during day time hours, however, there was a distinct increase in night-time systolic and diastolic BP leading to a disappearance of the physiological diurnal variation. Nabumetone caused a moderate increase of day and night BP, without changes in biological diurnal variation.

  2. Different characteristics of ventilator application between tracheostomy- and noninvasive positive pressure ventilation patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Park, Donghwi; Lee, Goo Joo; Kim, Ha Young; Ryu, Ju Seok

    2017-03-01

    The aim of the study was to investigate the appropriate home ventilator settings for patients with amyotrophic lateral sclerosis (ALS).In total, 71 patients with ALS, who had received either a noninvasive positive pressure ventilation (NIPPV) or tracheostomy positive pressure ventilation (TPPV), were included. Accordingly, patients were divided into 2 groups (the TPPV and NIPPV groups). We retrospectively evaluated the values used in home ventilators for patients with ALS, who had maintained a stable level of CO2 on both the arterial blood gas analysis (ABGA) and transcutaneous blood gas monitoring. To measure the main outcome, we also investigated the actual body weight (ABW) and predicted body weight (PBW) of patients, and the following setting values of ventilators were also recorded: the inspired tidal volume (VTi), minute ventilation (MV), peak inspiratory pressure (PIP), positive end expiratory pressure (PEEP), and inspiratory time (Tins).VTi and MV showed a significantly positive correlation with both PBW and ABW of patients in the TPPV group. However, both VTi and MV had greater significant correlation with PBW than ABW in the TPPV group. In addition, VTi and MV did not show a significantly positive correlation with either PBW or ABW in the NIPPV group.In patients with ALS, PBW was more useful for predicting VTi and MV than ABW. Moreover, it will be helpful to know the differences of setting values between TPPV and NIPPV, especially because ALS patients are usually treated with TPPV due to the initial difficulties associated with NIPPV.

  3. Acoustic performance of low pressure axial fan rotors with different blade chord length and radial load distribution

    Science.gov (United States)

    Carolus, Thomas

    The paper examines the acoustic and aerodynamic performance of low-pressure axial fan rotors with a hub/tip ratio of 0.45. Six rotors were designed for the same working point by means of the well-known airfoil theory. The condition of an equilibrium between the static pressure gradient and the centrifugal forces is maintained. All rotors have unequally spaced blades to diminish tonal noise. The rotors are tested in a short cylindrical housing without guide vanes. All rotors show very similar flux-pressure difference characteristics. The peak efficiency and the noise performance is considerably influenced by the chosen blade design. The aerodynamically and acoustically optimal rotor is the one with the reduced load at the hub and increased load in the tip region under satisfied equilibrium conditions. It runs at the highest aerodynamic efficiency, and its noise spectrum is fairly smooth. The overall sound pressure level of this rotor is up to 8 dB (A) lower compared to the other rotors under consideration.

  4. Noninvasive 4D pressure difference mapping derived from 4D flow MRI in patients with repaired aortic coarctation: comparison with young healthy volunteers.

    Science.gov (United States)

    Rengier, Fabian; Delles, Michael; Eichhorn, Joachim; Azad, Yoo-Jin; von Tengg-Kobligk, Hendrik; Ley-Zaporozhan, Julia; Dillmann, Rüdiger; Kauczor, Hans-Ulrich; Unterhinninghofen, Roland; Ley, Sebastian

    2015-04-01

    To assess spatial and temporal pressure characteristics in patients with repaired aortic coarctation compared to young healthy volunteers using time-resolved velocity-encoded three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) and derived 4D pressure difference maps. After in vitro validation against invasive catheterization as gold standard, 4D flow MRI of the thoracic aorta was performed at 1.5T in 13 consecutive patients after aortic coarctation repair without recoarctation and 13 healthy volunteers. Using in-house developed processing software, 4D pressure difference maps were computed based on the Navier-Stokes equation. Pressure difference amplitudes, maximum slope of pressure amplitudes and spatial pressure range at mid systole were retrospectively measured by three readers, and twice by one reader to assess inter- and intraobserver agreement. In vitro, pressure differences derived from 4D flow MRI showed excellent agreement to invasive catheter measurements. In vivo, pressure difference amplitudes, maximum slope of pressure difference amplitudes and spatial pressure range at mid systole were significantly increased in patients compared to volunteers in the aortic arch, the proximal descending and the distal descending thoracic aorta (p coarctation.

  5. Different associations between beta-blockers and other antihypertensive medication combinations with brachial blood pressure and aortic waveform parameters.

    Science.gov (United States)

    Sluyter, John D; Hughes, Alun D; Lowe, Andrew; Parker, Kim H; Camargo, Carlos A; Hametner, Bernhard; Wassertheurer, Siegfried; Scragg, Robert K R

    2016-09-15

    Comparing the relationships of antihypertensive medications with brachial blood pressure (BP) and aortic waveform parameters may help clinicians to predict the effect on the latter in brachial BP-based antihypertensive therapy. We aimed to make such comparisons with new waveform measures and a wider range of antihypertensive regimens than examined previously. Cross-sectional analysis of 2933 adults (61% male; aged 50-84years): 1637 on antihypertensive treatment and 1296 untreated hypertensives. Sixteen medicine regimens of up to 4 combinations of drugs from 6 antihypertensive classes were analysed. Aortic systolic BP, augmentation index (AIx), excess pressure integral (EPI), backward pressure amplitude (Pb), reflection index (RI) and pulse wave velocity (PWV) were calculated from aortic pressure waveforms derived from suprasystolic brachial measurement. Forest plots of single-drug class comparisons across regimens with the same number of drugs (for between 1- and 3-drug regimens) revealed that AIx, Pb, RI and/or loge(EPI) were higher (maximum difference=5.6%, 2.2mmHg, 0.0192 and 0.13 loge(mmHg⋅s), respectively) with the use of a beta-blocker compared with vasodilators and diuretics, despite no brachial systolic and diastolic BP differences. These differences were reduced (by 34-57%) or eliminated after adjustment for heart rate, and similar effects occurred when controlling for systolic ejection period or diastolic duration. Beta-blocker effects on brachial BP may overestimate effects on aortic waveform parameters. Compared to other antihypertensives, beta-blockers have weaker associations with wave reflection measures and EPI; this is predominantly due to influences on heart rate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Blood pressure, heart rate and tubuloglomerular feedback in A1AR-deficient mice with different genetic backgrounds.

    Science.gov (United States)

    Kim, S M; Mizel, D; Qin, Y; Huang, Y; Schnermann, J

    2015-01-01

    Differences in genetic background between control mice and mice with targeted gene mutations have been recognized as a potential cause for phenotypic differences. In this study, we have used A1AR-deficient mice in a C57Bl/6 and SWR/J congenic background to assess the influence of background on the effect of A1AR-deficiency on cardiovascular and renal functional parameters. In A1AR+/+ and A1AR-/- mice in C57Bl/6 and SWR/J congenic backgrounds, we assessed blood pressure and heart rate using radio-telemetry, plasma renin concentrations and tubuloglomerular feedback. We did not detect significant differences in arterial blood pressure (MAP) and heart rates (HR) between A1AR+/+ and A1AR-/- mice in either C57Bl/6, SWR/J or mixed backgrounds. MAP and HR were significantly higher in SWR/J than in C57Bl/6 mice. A high NaCl intake increased MAP in A1AR-/- mice on C57Bl/6 background while there was less or no salt sensitivity in the SWR/J background. No significant differences in plasma renin concentration were detected between A1AR-/- and A1AR+/+ mice in any of the strains. Tubuloglomerular feedback was found to be absent in A1AR-/- mice with SWR/J genetic background. While this study confirmed important differences between inbred mouse strains, we did not identify phenotypic modifications of A1AR-related effects on blood pressure, heart rate and plasma renin by differences in genetic background. © 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  7. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sakshi Chopra

    2016-01-01

    Full Text Available Introduction: Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. Materials and Methods: The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. Results: A significant difference in the pressure produced using different impression materials was found (P < 0.001. Light body vinyl polysiloxane produced significantly lesser pressure than zinc oxide eugenol impression materials. The presence of relief did affect the magnitude of pressure at various locations. Conclusion: All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Clinical Implication: Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  8. 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.

  9. Different selection pressures give rise to distinct ethnic phenomena : a functionalist framework with illustrations from the Peruvian Altiplano.

    Science.gov (United States)

    Moya, Cristina; Boyd, Robert

    2015-03-01

    Many accounts of ethnic phenomena imply that processes such as stereotyping, essentialism, ethnocentrism, and intergroup hostility stem from a unitary adaptation for reasoning about groups. This is partly justified by the phenomena's co-occurrence in correlational studies. Here we argue that these behaviors are better modeled as functionally independent adaptations that arose in response to different selection pressures throughout human evolution. As such, different mechanisms may be triggered by different group boundaries within a single society. We illustrate this functionalist framework using ethnographic work from the Quechua-Aymara language boundary in the Peruvian Altiplano. We show that different group boundaries motivate different ethnic phenomena. For example, people have strong stereotypes about socioeconomic categories, which are not cooperative units, whereas they hold fewer stereotypes about communities, which are the primary focus of cooperative activity. We also show that, despite the cross-cultural importance of ethnolinguistic boundaries, the Quechua-Aymara linguistic distinction does not strongly motivate any of these intergroup processes.

  10. Age-related differences in motor coordination during simultaneous leg flexion and finger extension: influence of temporal pressure.

    Science.gov (United States)

    Hussein, Tarek; Yiou, Eric; Larue, Jacques

    2013-01-01

    Although the effect of temporal pressure on spatio-temporal aspects of motor coordination and posture is well established in young adults, there is a clear lack of data on elderly subjects. This work examined the aging-related effects of temporal pressure on movement synchronization and dynamic stability. Sixteen young and eleven elderly subjects performed series of simultaneous rapid leg flexions in an erect posture paired with ipsilateral index-finger extensions, minimizing the difference between heel and finger movement onsets. This task was repeated ten times under two temporal conditions (self-initiated [SI] vs. reaction-time [RT]). Results showed that, first, temporal pressure modified movement synchronization; the finger extension preceded swing heel-off in RT, and inversely in SI. Synchronization error and associated standard deviation were significantly greater in elderly than in young adults in SI only, i.e. in the condition where proprioception is thought to be crucial for temporal coordination. Secondly, both groups developed a significantly shorter mediolateral (ML) anticipatory postural adjustment duration in RT (high temporal pressure) than in SI. In both groups, this shortening was compensated by an increase in the anticipatory peak of centre-of-gravity (CoG) acceleration towards the stance-leg so that ML dynamic stability at foot-off, quantified with the "extrapolated centre-of-mass", remained unchanged across temporal conditions. This increased CoG acceleration was associated with an increased anticipatory peak of ML centre-of-pressure shift towards the swing-leg in young adults only. This suggested that the ability to accelerate the CoG with the centre-of-pressure shift was degraded in elderly, probably due to weakness in the lower limb muscles. Dynamic stability at foot-off was also degraded in elderly, with a consequent increased risk of ML imbalance and falling. The present study provides new insights into the ability of elderly adults to deal

  11. Age-related differences in motor coordination during simultaneous leg flexion and finger extension: influence of temporal pressure.

    Directory of Open Access Journals (Sweden)

    Tarek Hussein

    Full Text Available Although the effect of temporal pressure on spatio-temporal aspects of motor coordination and posture is well established in young adults, there is a clear lack of data on elderly subjects. This work examined the aging-related effects of temporal pressure on movement synchronization and dynamic stability. Sixteen young and eleven elderly subjects performed series of simultaneous rapid leg flexions in an erect posture paired with ipsilateral index-finger extensions, minimizing the difference between heel and finger movement onsets. This task was repeated ten times under two temporal conditions (self-initiated [SI] vs. reaction-time [RT]. Results showed that, first, temporal pressure modified movement synchronization; the finger extension preceded swing heel-off in RT, and inversely in SI. Synchronization error and associated standard deviation were significantly greater in elderly than in young adults in SI only, i.e. in the condition where proprioception is thought to be crucial for temporal coordination. Secondly, both groups developed a significantly shorter mediolateral (ML anticipatory postural adjustment duration in RT (high temporal pressure than in SI. In both groups, this shortening was compensated by an increase in the anticipatory peak of centre-of-gravity (CoG acceleration towards the stance-leg so that ML dynamic stability at foot-off, quantified with the "extrapolated centre-of-mass", remained unchanged across temporal conditions. This increased CoG acceleration was associated with an increased anticipatory peak of ML centre-of-pressure shift towards the swing-leg in young adults only. This suggested that the ability to accelerate the CoG with the centre-of-pressure shift was degraded in elderly, probably due to weakness in the lower limb muscles. Dynamic stability at foot-off was also degraded in elderly, with a consequent increased risk of ML imbalance and falling. The present study provides new insights into the ability of

  12. 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.

  13. On the pressure difference ranges which assure a specified gap size for semiconductor crystals grown in terrestrial dewetted Bridgman

    Science.gov (United States)

    Braescu, L.

    2010-04-01

    The complexity of the dewetting phenomenon on the ground consists mainly in the presence of the hydrostatic pressure which should be counterbalanced by a supplementary gas pressure difference ΔP=Pc-Ph between the cold and hot sides of the sample. The experiments have shown that using uncoated and coated crucibles, detached and partially detached growth can be obtained; dewetting became unsuccessful when the liquid-solid interface changed its shape—phenomenon which proved connection between the meniscus shape, pressure difference and stable dewetting. Because the interest is to grow crystals with specified gap size, the ΔP limits and the corresponding menisci shapes for which dewetting is feasible are first established, on the base of the theoretical and computational investigations. Then, for the obtained menisci, the static stability via the conjugate point criterion of the calculus of variations is studied in the cases of the classical semiconductors grown in (i) uncoated crucibles (i.e., the wetting angle θc and growth angle αe satisfy the inequality θc+αeii) coated crucibles or pollution ( θc+αe≥180∘). In this way, gap thickness limitations for which the menisci are physically realizable are obtained. Numerical results are performed for InSb crystal grown in uncoated ampoule, and for Ge crystal grown in coated ampoule.

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

    CERN Document Server

    Gu, Ziyu; van de Water, Willem; Ubachs, Wim

    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 measurements performed at a wavelength of 366.8 nm detect spontaneous RB scattering at a 90 degree scattering angle from a sensitive intracavity setup, delivering scattering profiles at a 1 percent rms noise level or better. The elusive transport coefficient, the bulk viscosity, is effectively derived by a comparing the measurements to the model, yielding an increased trend. The calculated (Tenti S6) line shapes are consistent with experimental data at the level of 2 percent, meeting the requirements for the future RB scattering LIDAR missions in the Earth's atmosphere. However, the systematic 2 percent deviation may imply that the model has a limit to describe the finest details of RB scattering in air. Finally, it...

  15. 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.

  16. Comparative immediate effect of different yoga asanas on heart rate and blood pressure in healthy young volunteers

    Science.gov (United States)

    Bhavanani, Ananda Balayogi; Ramanathan, Meena; Balaji, R; Pushpa, D

    2014-01-01

    Introduction: This study planned to compare immediate cardiovascular effects of different yoga asanas in healthy young volunteers. Materials and Methods: Heart rate (HR), systolic pressure (SP), and diastolic pressure (DP), blood pressure (BP), were recorded using the non invasive blood pressure (NIBP) apparatus in 22 healthy young subjects, before and after the performance of Dhanurasana (DA), Vakrasana (VA) (both sides), Janusirasasana (JSA) (both sides), Matsyasana and Shavasana for 30 s. HR and BP were further recorded during supine recovery at 2, 4, 6, 8, and 10 min. A repeated measure of ANOVA was used for statistical analysis. Results: There were significant changes in HR and BP both immediately after the Asanas as well as during the recovery period. Overall comparisons of ∆% changes immediately after the performance of the Asanas revealed significant differences with regard to HR that increased significantly after DA. In the recovery phase, there were significant intergroup differences from 2 min onward in both SP and DP. The decrease of SP after VA (right side) (VA-R) was significantly greater than Shavasana (4th, 6th, and 8th min) and JSA (left side) (JSA-L) at 6th and 8th min. DP decreased significantly after performing JSA-L compared to VA-R at the 6th and 8th min. Discussion: The cardiovascular changes immediately after the Asanas and during the recovery phase reveal inherent differences between the selected postures. The rise of HR in DA may be attributed to increased sympathetic response due to the relative difficulty of the posture as well as abdominal compression occurring in it. The effect of supine relaxation is more pronounced after the performance of the Asanas as compared to mere relaxation in Shavasana. This may be attributed to a normalization and resultant homeostatic effect occurring due to a greater, healthier de-activation of the autonomic nervous system occurring towing to the presence of prior activation. There were also subtle

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

    Science.gov (United States)

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

    2017-08-30

    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. 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 6h during the first day in the ICU. 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 (p60min, 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. 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 60min. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  18. Age differences in response to conformity pressure for emotional and nonemotional material.

    Science.gov (United States)

    Pasupathi, M

    1999-03-01

    Most theories of social influence do not consider adult development. Theoretical and empirical work in life span developmental psychology, however, suggests that age may reduce susceptibility to social influence. The present study examined age differences in social conformity for 2 classes of stimuli: judgments of geometric shapes and emotional facial expressions. As predicted, older people, compared with their younger counterparts, displayed lower rates of social conformity, and this age difference was most evident when judging emotional facial expressions.

  19. Atmospheric pressure ionization and gas phase ion mobility studies of isomeric dihalogenated benzenes using different ionization techniques

    Science.gov (United States)

    Borsdorf, H.; Nazarov, E. G.; Eiceman, G. A.

    2004-03-01

    Ion mobility spectrometry (IMS) featuring different ionization techniques was used to analyze isomeric ortho-, meta- and para-dihalogenated benzenes in order to assess how structural features affect ion formation and drift behavior. The structure of the product ions formed was investigated by atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) and IMS-MS coupling. Photoionization provided [M]+ ions for chlorinated and fluorinated compounds while bromine was cleaved from isomers of dibromobenzene and bromofluorobenzene. This ionization technique does not permit the different isomers to be distinguished. Comparable ions and additional clustered ions were obtained using 63Ni ionization. Depending on the chemical constitution, different clustered ions were observed in ion mobility spectra for the separate isomers of dichlorobenzene and dibromobenzene. Corona discharge ionization permits the most sensitive detection of dihalogenated compounds. Only clustered product ions were obtained. Corona discharge ionization enables the classification of different structural isomers of dichlorobenzene, dibromobenzene and bromofluorobenzene.

  20. Blood flow response in small intestinal loops at different depths during negative pressure wound therapy of the open abdomen.

    Science.gov (United States)

    Lindstedt, Sandra; Hlebowicz, Joanna

    2013-08-01

    High closure rates of the open abdomen have been reported following negative pressure wound therapy (NPWT). However, the method has occasionally been associated with increased development of intestinal fistulae. We have previously shown that the application of NPWT to the open abdomen causes a decrease in microvascular blood flow in the small intestinal loop and the omentum adjacent to the visceral protective layer of the dressing. In this study we investigate whether the negative pressure affects only small intestinal loops lying directly below the dressing or if it also affects small intestinal loops that are not in direct contact with the dressing. Six pigs underwent midline incision and application of NPWT to the open abdomen. The microvascular blood flow was measured in four intestinal loops at different depths from the visceral protective layer, at two different locations: beneath the dressing and at the anterior abdominal wall, before and after the application of NPWT of -50, -70, -100, -120, -150 and -170 mmHg, using laser Doppler velocimetry. Negative pressures between -50 and -170 mmHg caused a significant decrease in the microvascular blood flow in the intestinal loops in direct contact with the visceral protective layer. A slight, but significant, decrease in blood flow was also seen in the intestinal loops lying beneath these loops. The decrease in microvascular blood flow increased with the amount of negative pressure applied. No difference in blood flow was seen in the intestinal loops lying deeper in the abdominal cavity. A decrease in blood flow was seen in the upper two intestinal loops located apically and anteriorly, but not in the lower two, indicating that this is a local effect and that pressure decreases with distance from the source. A long-term decrease in blood flow in the intestinal wall may induce ischaemia and secondary necrosis in the intestinal wall, which could promote the development of intestinal fistulae. We believe that NPWT of

  1. A Numerical Analysis of Droplet Breakup in Asymmetric T-Junctions with Different Outlet Pressure Gradients

    Science.gov (United States)

    Cheng, Way Lee; Han, Arum; Sadr, Reza

    2016-11-01

    Droplet splitting is the breakup of a parent droplet into two or more daughter droplets of desired sizes. It is done to improve production efficiency and investigational capacity in microfluidic devices. Passive splitting is the breakup of droplets into precise volume ratios at predetermined locations without external power sources. In this study, a 3-D simulation was conducted using the Volume-of-Fluid method to analysis the breakup process of a droplet in asymmetric T-junctions with different outlet arm lengths. The arrangement allows a droplet to be split into two smaller droplets of different sizes, where the volumetric ratio of the daughter droplets depends on the length ratios of the outlet arms. The study identified different breakup regimes such as primary, transition, bubble and non-breakup under different flow conditions and channel configurations. Furthermore, a close analysis to the primary breakup regimes were done to determine the breakup mechanisms at various flow conditions. The analysis show that the breakup mechanisms in asymmetric T-junctions is different than a regular split. A pseudo-phenomenological model for the breakup criteria was presented at the end. The model was an expanded version to a theoretically derived model for the symmetric droplet breakup. The Qatar National Research Fund (a member of the Qatar Founda- tion), under Grant NPRP 5-671-2-278, supported this work.

  2. 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.

  3. Daily environmental differences in blood pressure and heart rate variability in healthy premenopausal women.

    Science.gov (United States)

    James, Gary D; Bovbjerg, Dana H; Hill, Leah A

    2015-01-01

    As daily environments change, behavior and activity also change and as blood pressure (BP) and heart rate (HR) are allostatically tied to these factors, one might expect that environments that elicit the greatest behavioral/activity variation should also evince the highest BP and HR variability [standard deviation (SD) or coefficient of variation (CV)]. The purpose of this study was to evaluate this premise. Two hundred and six women (age = 37.6 ± 9.1 years) wore an ambulatory BP monitor on a midweek workday. All worked in clerical, technical, or professional positions. Ambulatory BP and HR Means, SDs and CVs at work (11 AM-3 PM), home (∼6-10 PM) and during sleep (∼10 PM-6 AM) were compared using repeated measures ANCOVA. Mean BP and HR decreased from work and home to sleep [121 ± 11, 120 ± 11 vs. 107 ± 12 systolic; 82 ± 10, 80 ± 11 vs. 66 ± 11 diastolic; 79 ± 12, 80 ± 12 vs. 68 ± 11 HR (all P < 0.001)], while the CV of systolic and diastolic BP increased [0.06 ± 0.02, 0.07 ± 0.02 vs. 0.08 ± 0.03 systolic; 0.09 ± 0.03, 0.10 ± 0.04 vs. 0.12 ± 0.05 diastolic (P < 0.001)]. The HR SD decreased during sleep [8.1 ± 3.8, 8.2 ± 3.8 vs. 6.9 ± 3.2 (P < 0.001)]. HR variability follows the expected variability pattern with behavior and activity, whereas BP does not. © 2014 Wiley Periodicals, Inc.

  4. The efficacy of low-pressure lavage with different irrigating solutions to remove adherent bacteria from bone.

    Science.gov (United States)

    Bhandari, M; Adili, A; Schemitsch, E H

    2001-03-01

    Recent studies have suggested that high-pressure irrigation may have adverse effects on bone. However, the use of low-pressure irrigation may not remove all adherent bacteria from bone. The type of irrigating solution may be an important factor in the removal of adherent bacteria with pulsatile lavage. In this study, we compared the effects of various irrigating solutions on the number and function of osteoblasts and osteoclasts and we examined the effectiveness of these solutions in removing adherent bacteria from bone. To examine the effect of irrigating solutions on the number and activity of osteoblasts, we isolated calvarial cells from newborn C57BI/6 mice and exposed the cells to equivalent concentrations of ethanol, povidoneiodine, liquid soap, antimicrobial wash (50 U/L of bacitracin), or chlorhexidine gluconate, for two, ten, or twenty minutes. The cells were then cultured in the presence of bone-nodule-enhancing medium (beta-glycerophosphate and ascorbic acid) for twenty-one days. The medium was changed every three or four days. Mineralized nodules were stained with alizarin red S, and osteoblasts were stained with a histochemical stain for alkaline phosphatase. Osteoclasts were identified with tartrate-resistant acid-phosphatase staining. In a second experiment, canine cortical tibiae were contaminated with Staphylococcus aureus for six hours and subjected to different irrigating solutions with or without low-pressure lavage. Bacterial colony-forming units were quantitated under each set of conditions. Each solution resulted in a time-dependent decrease in the number of calvarial osteoblasts and osteoclasts compared with that in the controls. The 1% soap solution resulted in greater preservation of both alkaline-phosphatase activity and bone-nodule formation than did the other solutions. Moreover, the soap solution preserved the number of osteoclasts to the greatest extent. The povidone-iodine and chlorhexidine-gluconate solutions resulted in the largest

  5. Computational analysis of heat transfer and pressure drop performance for internally finned tubes with three different longitudinal wavy fins

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiu-Wang; Lin, Mei; Zeng, Min; Tian, Lin [Xi' an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an, Shaanxi (China)

    2008-12-15

    Turbulent pressure drop and heat transfer characteristics in tubes with three different kinds of internally longitudinal fin patterns (interrupted wavy, sinusoidal wavy and plain) are numerically investigated for Re=904-4,520. The channel velocity, temperature, and turbulence fields are obtained to discern the mechanisms of heat transfer enhancement. Numerical results indicate that the steady and spatially periodic growth and disruption of cross-sectional vortices occur near the tube/fin walls along the streamwise locations. The thermal boundary layers near the tube/fin surfaces are thereby periodically interrupted, with heat transfer near the recirculation zones being enhanced. The overall heat transfer coefficients in wavy channels are higher than those in a plain fin channel, while with larger pressure drop penalties. At the same waviness, the interrupted wavy fin tube could enhance heat transfer by 72-90%, with more than 2-4 times of pressure drop penalty. Among the fins studied, the sinusoidal wavy fin has the best comprehensive performance. (orig.)

  6. The effect of pressure on tricalcium silicate hydration at different temperatures and in the presence of retarding additives

    Energy Technology Data Exchange (ETDEWEB)

    Jupe, Andrew C.; Wilkinson, Angus P.; Funkhouser, Gary P. (Halliburton); (GIT)

    2012-07-25

    The hydration of tricalcium silicate (C{sub 3}S) is accelerated by pressure. However, the extent to which temperature and/or cement additives modify this effect is largely unknown. Time-resolved synchrotron powder diffraction has been used to study cement hydration as a function of pressure at different temperatures in the absence of additives, and at selected temperatures in the presence of retarding agents. The magnitudes of the apparent activation volumes for C{sub 3}S hydration increased with the addition of the retarders sucrose, maltodextrin, aminotri(methylenephosphonic acid) and an AMPS copolymer. Pressure was found to retard the formation of Jaffeite relative to the degree of C{sub 3}S hydration in high temperature experiments. For one cement slurry studied without additives, the apparent activation volume for C{sub 3}S hydration remained close to {approx} -28 cm{sup 3} mol{sup -1} over the range 25 to 60 C. For another slurry, there were possible signs of a decrease in magnitude at the lowest temperature examined.

  7. Influence of center of pressure estimation errors on 3D inverse dynamics solutions during gait at different velocities.

    Science.gov (United States)

    Camargo-Junior, Franklin; Ackermann, Marko; Loss, Jefferson F; Sacco, Isabel C N

    2013-12-01

    The aim of this study was to investigate the effect of errors in the location of the center of pressure (5 and 10 mm) on lower limb joint moment uncertainties at different gait velocities (1.0, 1.5, and 2.0 m/s). Our hypotheses were that the absolute joint moment uncertainties would be gradually reduced from distal to proximal joints and from higher to lower velocities. Joint moments of five healthy young adults were calculated by inverse dynamics using the bottom-up approach, depending on which estimate the uncertainty propagated. Results indicated that there is a linear relationship between errors in center of pressure and joint moment uncertainties. The absolute moment peak uncertainties expressed on the anatomic reference frames decreased from distal to proximal joints, confirming our first hypothesis, except for the abduction moments. There was an increase in moment uncertainty (up to 0.04 N m/kg for the 10 mm error in the center of pressure) from the lower to higher gait velocity, confirming our second hypothesis, although, once again, not for hip or knee abduction. Finally, depending on the plane of movement and the joint, relative uncertainties experienced variation (between 5 and 31%), and the knee joint moments were the most affected.

  8. Wind- and Rain-Induced Vibrations Impose Different Selection Pressures on Multimodal Signaling.

    Science.gov (United States)

    Halfwerk, Wouter; Ryan, Michael J; Wilson, Preston S

    2016-09-01

    The world is a noisy place, and animals have evolved a myriad of strategies to communicate in it. Animal communication signals are, however, often multimodal; their components can be processed by multiple sensory systems, and noise can thus affect signal components across different modalities. We studied the effect of environmental noise on multimodal communication in the túngara frog (Physalaemus pustulosus). Males communicate with rivals using airborne sounds combined with call-induced water ripples. We tested males under control as well as noisy conditions in which we mimicked rain- and wind-induced vibrations on the water surface. Males responded more strongly to a multimodal playback in which sound and ripples were combined, compared to a unimodal sound-only playback, but only in the absence of rain and wind. Under windy conditions, males decreased their response to the multimodal playback, suggesting that wind noise interferes with the detection of rival ripples. Under rainy conditions, males increased their response, irrespective of signal playback, suggesting that different noise sources can have different impacts on communication. Our findings show that noise in an additional sensory channel can affect multimodal signal perception and thereby drive signal evolution, but not always in the expected direction.

  9. Comparative assessment of cyclic J-R curve determination by different methods in a pressure vessel steel

    Science.gov (United States)

    Chowdhury, Tamshuk; Sivaprasad, S.; Bar, H. N.; Tarafder, S.; Bandyopadhyay, N. R.

    2016-04-01

    Cyclic J-R behaviour of a reactor pressure vessel steel using different methods available in literature has been examined to identify the best suitable method for cyclic fracture problems. Crack opening point was determined by moving average method. The η factor was experimentally determined for cyclic loading conditions and found to be similar to that of ASTM value. Analyses showed that adopting a procedure analogous to the ASTM standard for monotonic fracture is reasonable for cyclic fracture problems, and makes the comparison to monotonic fracture results straightforward.

  10. Sex differences in time trends of blood pressure among Swedish septuagenarians examined three decades apart: a longitudinal population study.

    Science.gov (United States)

    Joas, Erik; Guo, Xinxin; Kern, Silke; Östling, Svante; Skoog, Ingmar

    2017-07-01

    The aim of this study was to analyze the influence of birth cohort, sex and age on the trajectories of SBP and DBP in two birth cohorts of 70-year-olds, examined 3 decades apart and followed up at ages 75 and 79-80 years. Two population samples of 70-year-olds from Gothenburg, Sweden, were examined. The first, born in 1901-1902, was examined in 1971-1972 (n = 973). The second, born in 1930, was examined in 2000 (n = 509). Both samples were re-examined at ages 75 and 79-80 years. We found that SBP and DBP were considerably lower in septuagenarian men and women born 1930 compared with those born 1901-1902, also when adjusting for antihypertensive treatment in different ways. The decline was especially pronounced in women. Blood pressure was higher in women than in men in the 1970s, whereas there were no sex differences in the 2000s. The age-related decline in SBP started earlier and was more accentuated in those born in 1930 than in those born in 1901-1902. Blood pressure decreased, and the age-related decline in SBP started earlier in septuagenarians examined in the 2000s compared with those examined in the 1970s. The decrease was especially pronounced in women and diminished the sex differences. Antihypertensive treatment only partly explained our findings, suggesting that other mostly unknown factors played an important role.

  11. Intraperitoneal and retroperitoneal carbon dioxide insufflation evoke different effects on caval vein pressure gradients in humans: evidence for the starling resistor concept of abdominal venous return.

    Science.gov (United States)

    Giebler, R M; Behrends, M; Steffens, T; Walz, M K; Peitgen, K; Peters, J

    2000-06-01

    The authors hypothesized that intraperitoneal and retroperitoneal carbon dioxide insufflation during surgical procedures evoke markedly different effects on the venous low-pressure system, induce different inferior caval vein pressure gradients at similar insufflation pressures, and may provide evidence for the Starling resistor concept of abdominal venous return. Intra- and extrathoracic caval vein pressures were measured using micromanometers during carbon dioxide insufflation at six cavity pressures (baseline and 10, 15, 20, and 24 mmHg and desufflation) in 20 anesthetized patients undergoing laparoscopic (supine, n = 8) or left (n = 6) or right (n = 6) retroperitoneoscopic (prone position) surgery. Intracavital, esophageal, and gastric pressures also were assessed. Data were analyzed for insufflation pressure-dependent and group effects by one-way and two-way analysis of variance for repeated measurements, respectively, followed by the Newman-Keuls post hoc test (P < 0.05). Intraperitoneal, unlike retroperitoneal, insufflation markedly increased, in an insufflation pressure-dependent fashion, the inferior-to-superior caval vein pressure gradient (P < 0.00001) at the level of the diaphragm. In contrast to what was observed with retroperitoneal insufflation, transmural intrathoracic caval vein pressure increased at 10 mmHg insufflation pressure, but the increase flattened with an insufflation pressure of more than 10 mmHg, and pressure decreased with an inflation pressure of 20 mmHg (P = 0.0397). These data are consistent with a zone 2 or 3 abdominal vascular condition during intraperitoneal and a zone 3 abdominal vascular condition during retroperitoneal insufflation. Intraperitoneal but not retroperitoneal carbon dioxide insufflation evokes a transition of the abdominal venous compartment from a zone 3 to a zone 2 condition, presumably impairing venous return, supporting the Starling resistor concept of abdominal venous return in humans.

  12. 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.

  13. Investigation of different modeling approaches for computational fluid dynamics simulation of high-pressure rocket combustors

    Science.gov (United States)

    Ivancic, B.; Riedmann, H.; Frey, M.; Knab, O.; Karl, S.; Hannemann, K.

    2016-07-01

    The paper summarizes technical results and first highlights of the cooperation between DLR and Airbus Defence and Space (DS) within the work package "CFD Modeling of Combustion Chamber Processes" conducted in the frame of the Propulsion 2020 Project. Within the addressed work package, DLR Göttingen and Airbus DS Ottobrunn have identified several test cases where adequate test data are available and which can be used for proper validation of the computational fluid dynamics (CFD) tools. In this paper, the first test case, the Penn State chamber (RCM1), is discussed. Presenting the simulation results from three different tools, it is shown that the test case can be computed properly with steady-state Reynolds-averaged Navier-Stokes (RANS) approaches. The achieved simulation results reproduce the measured wall heat flux as an important validation parameter very well but also reveal some inconsistencies in the test data which are addressed in this paper.

  14. Blood pressure variability and baroreflex sensitivity are not different in spontaneously hypertensive rats and stroke-prone spontaneously hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    Lin-shu ZHAN; Yun-feng GUAN; Ding-feng SU; Chao-yu MIAO

    2005-01-01

    Aim: To demonstrate and compare hemodynamic phenotypes of blood pressure (BP), blood pressure variability (BPV) and baroreflex sensitivity (BRS) in genetic hypertensive rats. Methods: BP was recorded continuously in conscious, freely moving rats using a computerized technique. BPV was expressed as the standard deviation of beat-to-beat BP values during a 1-h period. BRS was determined by measuring the heart period prolongation in response to the elevation in BP produced by an intravenous injection of phenylephrine. Results: Body weight and heart period were not different between spontaneously hypertensive rats (SHR)and stroke-prone spontaneously hypertensive rats (SHR-SP) at the age of 15weeks. The BP level was markedly higher in SHR-SP than SHR, whereas there were no significant differences in BPV and BRS. Quantitatively, systolic, diastolic and mean BP were significantly elevated by 36.9%, 42.9% and 39.5%, respectively,in SHR-SP compared with SHR (P<0.01). However, their variabilities were elevated only by 14.0%, 0.4% and 10.1%, respectively, without statistical significance (P>0.05). Conclusion: BPV and BRS were not changed in parallel with the BP alterations in SHR and SHR-SP.

  15. 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 (pindustrial 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.

  16. 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.

  17. Does Airway Pressure Release Ventilation Mode Make Difference in Cardiopulmonary Function of ICU Patients?

    Directory of Open Access Journals (Sweden)

    Maziar Mahjoubifard

    2015-11-01

    Full Text Available Introduction: Tuberculosis (TB, with different types of respiratory tract involvements, has a high rate of mortality all around the world. Endobronchial involvement, which is a slightly common tuberculous infection, requires special attention due to its severe complications such as bronchostenosis. Aim of study of this study was describes, one type of pulmonary tuberculosis with less diagnosed and delayed treatment. High suspicious needs to diagnose and may be need bronchoscopy for confirmed the diagnosis. It can be associated with sever complication and early diagnosis and treatment are necessary for prevention of adverse effect. Materials and Methods: This retrospective study was conducted in a teaching hospital during 2005-2010. Patients diagnosed with endobronchial tuberculosis through bronchoscopic biopsy were included in the study. Diagnosis was confirmed by observation of caseous necrosis, bronchial lavage fluid or positive acid-fast staining in tissue samples obtained through bronchial biopsy. Moreover, demographic information, endobronchial view, lab tests, as well as clinical and radiographic findings were reviewed and evaluated retrospectively. Results: A total of 20 cases were confirmed with endobronchial tuberculosis, 75% of whom were female with the mean age of 60 years. The results showed that the most common clinical symptom was cough (80%, the most common finding in the chest X-ray was consolidation (75%, and the most common bronchoscopic feature was anthracosis (55%. Conclusion: TB is still a major concern, particularly in the developing countries. Thus, in order for early diagnosis and prevention of this disease, we need to pay meticulous attention to its clinical manifestations and bronchoscopic features.

  18. Evaluation of tensile strength and fracture behavior of friction welded dissimilar steels under different rotational speeds and axial pressures

    Indian Academy of Sciences (India)

    Amit Handa; Vikas Chawla

    2015-08-01

    In the present study an attempt was made to join austenitic stainless steel (AISI 304) with low alloy steel (AISI 1021) at five different rotational speeds ranging from 800 to 1600 rpm and at as many different axial pressures ranging from 75 MPa to 135 MPa and then determining the strength of the joint by means of tensile strength. Furthermore scanning electron microscope analysis was performed to evaluate the pattern of failure at the fractured locations, also the micro hardness was checked at the weld interface and at distances on either side of the weld joint to evaluate the effect of heat. The highest tensile strength achieved by the welded specimens was 1.8% higher than the AISI 1021 steel and the lowest tensile strength obtained was 20% lower than the parent AISI 1021.

  19. Influence of different intrapulpal pressure simulation liquids on the microtensile bond strength of adhesive systems to dentin.

    Science.gov (United States)

    Mobarak, Enas H; El-Deeb, Heba A; Yousry, Mai M

    2013-12-01

    To evaluate the effect of three different liquids used for intrapulpal pressure (IPP) simulation on the microtensile bond strength (µTBS) of three adhesive systems to dentin. The occlusal surfaces of sound human molars were ground flat down to mid-dentin depth. The teeth were bonded under 15 mmHg simulated IPP using distilled water, phosphate buffered saline, or human plasma as a simulating liquid. Three adhesive systems were tested: a single-bottle etch-and-rinse adhesive (SingleBond, 3M ESPE), and two single-step self-etching adhesives (G-Bond, GC) and (iBond, Heraeus Kulzer). Resin composite (Tetric EvoCeram, Ivoclar Vivadent) buildups were made in 2 increments, each 2 mm in height. Specimens were stored in artificial saliva under 20 mmHg IPP at 37°C for 24 h prior to testing. µTBS (n = 15) was tested using a universal testing machine, and failure modes were determined. Data were statistically analyzed using ANOVA and Bonferroni post-hoc tests at p adhesive, distilled water showed significantly higher µTBS compared to plasma and phosphate buffered saline. With G-Bond, no significant difference was found between distilled water and phosphate buffered saline, whereas plasma showed significantly lower µTBS values. In contrast, no significant difference was encountered between the three IPP liquids for iBond adhesive. Predominant modes of failure were adhesive and mixed. A difference in intrapulpal pressure simulating liquids influences the bonding of adhesives to dentin. Etch-and-rinse adhesives are more sensitive to intrapulpal simulating liquids than are self-etching adhesives. Adhesives containing protein-coagulating components perform better with plasma perfusion than those lacking such components.

  20. 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

  1. INTRAOCULAR PRESSURE, MEAN ARTERIAL BLOOD PRESSURE AND PUPILLARY DIAMETER IN RABBITS ( (Oryctolagus cuniculus SUBJECTED TO RETROBULBAR BLOCK WITH DIFFERENT ANESTHETIC PROTOCOLS

    Directory of Open Access Journals (Sweden)

    Renata Maria Monção da Silva

    2015-10-01

    Full Text Available The aim of this study was to evaluate four protocols of loco regional anesthesia for ophthalmic procedures that could provide safety and life support, in addition to maintain intraocular pressure stable, with eye centralization and eyelid akinesia. 20 New Zealand rabbits were used to perform local anesthesia by retrobulbar block with four protocols: 2% lidocaine with epinephrine, 2% lidocaine without epinephrine associated with tramadol, 1% ropivacaine and bupivacaine 0.5 %. Each animal received an anesthetic volume of 1 mL. All anesthetic protocols used promoted eyelid akinesia and centralization of the eye during the assessment period. The retrobulbar block with the proposed anesthetic protocols proved to be feasible and safe for the maintenance of intraocular pressure, invasive blood pressure and pupillary diameter and can be used in intraocular surgeries, respecting the time of action of each anesthetic. All protocols showed an excellent blockage action but bupivacaine promoted the highest pupil diameter compared to the other drugs tested.

  2. Impact of different water activities (aw adjusted by solutes on high pressure high temperature inactivation of Bacillus amyloliquefaciens spores

    Directory of Open Access Journals (Sweden)

    Robert eSevenich

    2015-07-01

    Full Text Available Much research has been conducted to comprehend the mechanisms of high pressure (HP inactivation of spores in aqueous systems but for food model systems these information are scarce. In these systems spores can interact with ingredients which could lead to retarded inactivation, which can cause a problem for the sterilization process. The protective mechanism of a reduced a_W-value is still unclear. HP processing might prove valuable to overcome protective effects of solutes and achieve shorter process times for sterilization under HP. To gain insight into the underlying mechanisms five a_W-values (0.9, 0.92, 0.94, 0.96, 1 were adjusted with 2 different solutes (NaCl, sucrose. Solutions were inoculated with spores of Bacillus amyloliquefaciens and treated at 105,110°C and115°C at 600 MPa. A thermal inactivation was conducted at the same temperatures for a compraison with the high pressure data. The influence of high pressure high temperature treatment on the inactivation, the DPA-release and membrane constitution was assessed by plate count, HPLC and flow cytometry. The results show that during HP treatments sucrose and salt both have a protective effect, in which the influence of sucrose on the retarded inactivation is higher. The threshold aw, which is 0.94, here salt and sucrose have a significant influence on the inactivation. The comparison of thermal (105-115°C and high pressure and high temperature (600 MPa, 105-115°C treated samples showed that the time needed to achieve a 4-5 log inactivation can be reduced at 600 MPa.The release of dipicolinic acid (DPA is the rate limiting step of the inactivation and therefore monitoring the release is of great interest. The DPA-release is slowed is slowed down in high concentrated solutions (e.g. sucrose, salt in comparison to aw 1. Maybe as shown for vegetative microorganism the solutes can interact with membranes, e.g. inner spore membrane. FCM (flow cytometry measurement data show a similar

  3. 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...

  4. TGF-mediated oscillations in the proximal intratubular pressure: differences between spontaneously hypertensive rats and Wistar-Kyoto rats

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Leyssac, P P

    1986-01-01

    A highly sensitive oscillatory tubulo-glomerular feedback (TGF) response has previously been demonstrated in normotensive Sprague-Dawley rats. The purpose of the present study was to examine whether such as oscillating TGF-response could be elicited in Wistar-Kyoto rats (WKY) and genetically...... hypertensive rats (SHR) and furthermore if any differences in the TGF-response characteristics between SHR and WKY rats could be detected. The closed loop function of the TGF-system was studied. In 12-18-week-old WKY rats regular oscillations in the intratubular pressure occurred spontaneously. The median...... fluid (ATF). When furosemide was added to the ATF in a concentration of 0.1 mM, the oscillations were abolished in both strains of rats. It is concluded that, in both strains of rats the oscillatory phenomena depend upon TGF activity. It is suggested that the irregular pattern of the oscillations...

  5. Comparative analysis of different plant oils by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Jakab, Annamaria; Héberger, Károly; Forgács, Esther

    2002-11-01

    Different vegetable oil samples (almond, avocado, corngerm, grapeseed, linseed, olive, peanut, pumpkin seed, soybean, sunflower, walnut, wheatgerm) were analyzed using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. A gradient elution technique was applied using acetone-acetonitrile eluent systems on an ODS column (Purospher, RP-18e, 125 x 4 mm, 5 microm). Identification of triacylglycerols (TAGs) was based on the pseudomolecular ion [M+1]+ and the diacylglycerol fragments. The positional isomers of triacylglycerol were identified from the relative intensities of the [M-RCO2]+ fragments. Linear discriminant analysis (LDA) as a common multivariate mathematical-statistical calculation was successfully used to distinguish the oils based on their TAG composition. LDA showed that 97.6% of the samples were classified correctly.

  6. Rock Breaking Performance of a Pick Assisted by High-pressure Water Jet under Different Configuration Modes

    Institute of Scientific and Technical Information of China (English)

    LIU Songyong; LIU Xiaohui; CHEN Junfeng; LIN Mingxing

    2015-01-01

    In the process of rock breaking, the conical pick bears great cutting force and wear, as a result, high-pressure water jet technology is used to assist with cutting. However, the effect of the water jet position has not been studied for rock breaking using a pick. Therefore, the models of rock breaking with different configuration modes of the water jet are established based on SPH combined with FEM. The effect of the water jet pressure, distance between the jet and the pick bit, and cutting depth on the rock breaking performance as well as a comparison of the tension and compression stress are studied via simulation; the simulation results are verified by experiments. The numerical and experimental results indicate that the decrease in the rates of the pick force obviously increases from 25 MPa to 40 MPa, but slowly after 40 MPa, and the optimal distance between the jet and the pick bit is 2 mm under the JFP and JSP modes. The JCP mode is proved the best, followed by the modes of JRP and JFP, and the worst mode is JSP. The decrease in the rates of the pick force of the JCP, JRP, JFP, and JSP modes are up to 30.96%, 28.96%, 33.46%, 28.17%, and 25.42%, respectively, in experiment. Moreover, the JSP mode can be regarded as a special JFP model when the distance between the pick-tip and the jet impact point is 0 mm. This paper has a dominant capability in introducing new numerical and experimental method for the study of rock breaking assisted by water jet and electing the best water jet position from four different configuration modes.

  7. Study of nanosecond discharges in different H2 air mixtures at atmospheric pressure for plasma-assisted applications

    Science.gov (United States)

    Bourdon, Anne; Kobayashi, Sumire; Bonaventura, Zdenek; Tholin, Fabien; Popov, Nikolay

    2016-09-01

    This paper presents 2D simulations of nanosecond pulsed discharges between two point electrodes in different H2/air mixtures and in air at atmospheric pressure. A fluid model is coupled with detailed kinetic schemes for air and different H2/air mixtures to simulate the discharge dynamics. First, as the positive and negative ionization waves propagate in the interelectrode gap, it has been observed that in H2/air mixtures with equivalence ratios between 0.3 and 2, major positive ions produced by the nanosecond discharge are N2+,O2+and HN2+.The discharge dynamics is shown to vary only slightly for equivalence ratios of the H2/air mixture between 0.3 and 2. Then, as the discharge transits to a nanosecond spark discharge, we have studied the different chemical reactions that lead to fast gas heating and to the production of radicals, as O,H and OH. Both thermal and chemical effects of the nanosecond spark discharge are of interest for plasma assisted combustion applications. This work has been supported by the project DRACO (Grant No. ANR-13-IS09-0004) and the french russian LIA Kappa.

  8. 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.

  9. Effect of different carbon sources on the biological phosphorus removal by a sequencing batch reactor using pressurized pure oxygen.

    Science.gov (United States)

    Wei, Jie; Imai, Tsuyoshi; Higuchi, Takaya; Arfarita, Novi; Yamamoto, Koichi; Sekine, Masahiko; Kanno, Ariyo

    2014-05-04

    The effect of different carbon source on the efficiency of enhanced biological phosphorus removal (EBPR) from synthetic wastewater with acetate and two ratios of acetate/starch as a carbon source was investigated. Three pressurized pure oxygen sequencing batch reactor (POSBR) experiments were operated. The reactors (POSBR1, POSBR2 and POSBR3) were developed and studied at different carbon source ratios of 100% acetate, 75% acetate plus 25% starch and 50% acetate plus 50% starch, respectively. The results showed that POSBR1 had a higher phosphate release-to-uptake ratio and, respectively, in a much higher phosphorus removal efficiency (93.8%) than POSBR2 (84.7%) and POSBR3 (77.3%) within 30 days of operation. This indicated that the phosphorus removal efficiency decreased the higher the starch concentration was. It was also found that POSBR1 produced more polyhydroxyalkanoates (PHAs) than the other reactors. Based on the effect of the carbon source on the PHA concentration and consumption, the conditions of POSBR1 were favourable for the growth of polyphosphate-accumulating organisms and therefore, beneficial for the biological phosphorus removal process.

  10. 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.

  11. 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; Padult 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.

  12. Effect of Electronic Toilet System (Bidet) on Anorectal Pressure in Normal Healthy Volunteers: Influence of Different Types of Water Stream and Temperature

    Science.gov (United States)

    Ryoo, Seungbum; Song, Yoon Suk; Seo, Mi Sun; Oh, Heung-Kwon; Choe, Eun Kyung

    2011-01-01

    Although bidets are widely used in Korea, its effects on anorectal pressures have not been studied in detail in terms of the water settings used. Twenty healthy volunteers were placed on a toilet equipped with a bidet, and anorectal pressures were measured with a manometry catheter inserted into the rectum and anal canal before and after using the bidet at different water forces (40, 80, 160, 200 mN), temperatures (24℃ vs 38℃), and water jet widths (narrow vs wide). The pressure at anal high pressure zone decreased from 96.1 ± 22.5 to 81.9 ± 23.3 mmHg at water jet pressure of 40 mN and 38℃ wide water jet (P water jet pressure of 80 mN and 38℃ narrow water jet (P water jet pressure of 80 mN and 38℃ wide water jet (P water jet pressure, a warm water temperature, and a wide type water jet. PMID:21218033

  13. 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.

  14. Beat-by-beat analysis of cardiac output and blood pressure responses to short-term barostimulation in different body positions

    Science.gov (United States)

    Hildebrandt, Wulf; Schütze, Harald; Stegemann, J.

    Rapid quantification of the human baro-reflex control of heart rate has been achieved on a beat-by-beat basis using a neck-chamber with quick ECG-triggered pressure changes. Referring to recent findings on heart rate and stroke volume, the present study uses this technique to compare cardiac output as well as blood pressure changes in supine and upright position to investigate feedback effects and to confirm postural reflex modifications not revealed by RR-interval changes. A suction profile starting at +40 mmHg and running 7 steps of pressure decrease down to -65 mmHg was examined in 0° and 90° tilting position while beat-by-beat recordings were done of heart rate, stroke volume (impedance-cardiography) and blood pressure (Finapres tm) (n=16). The percentual heart rate decrease failed to be significantly different between positions. A suction-induced stroke volume increase led to a cardiac output almost maintained when supine and significantly increased when upright. A decrease in all blood pressure values was found during suction, except for systolic values in upright position which increased. Conclusively, (a) it is confirmed that different inotropy accounts for the seen gravitational effect on the cardiac output not represented by heart rate; (b) identical suction levels in different positions lead to different stimuli at the carotid receptor. This interference has to be considered in microgravity studies by beat-by-beat measurement of cardiac output and blood pressure.

  15. Absence of sex differences in systolic blood pressure and heart rate responses to exercise in healthy young adults.

    Science.gov (United States)

    Maruf, F A; Ogochukwu, U N; Dim, P A; Alada, A Ra

    2012-06-07

    The influence of sex on systolic blood pressure (SBP) and heart rate (HR) responses associated with cardiovascular morbidity, in healthy young adults was determined in ninety healthy young adults (47 females and 43 males) exercised using Bruce protocol. SBP and HR were measured pre- and post-exercise, and during recovery. SBPresponse (peak minus pre-exercise SBP), %SBPresponse [(peak minus pre-exercise SBP)÷pre-exercise SBP]x100, SBP3 (SBP 3 minutes into recovery), SBP4 (SBP 4 minutes into recovery), SBP3:peak (SBP3÷peak SBP), %SBPd3 [(peak SBP minus SBP 3 minutes into recovery)x peak SBP]x100, %SBPd4 [(peak SBP minus SBP 4 minutes into recovery)x peak SBP]X100, HRresponse (Peak HR minus pre-exercise HR), %HRresponse [(peak HR minus pre-exercise HR)÷pre-exercise HR]x 100, HR3 (HR 3 minutes into recovery), HR4 (HR 4 minutes into recovery), %HRd3 [(peak HR minus HR 3 minutes into recovery)÷peak HR]x100, %HRd4 [(peak HR minus HR 4 minutes into recovery)÷peak HR]X100, and HR50-70 (HR between 50th and 70th seconds into recovery) were derived from SBP and HR measurements. SBPpeak, HRresponse and %HRresponse were higher in males than in females whereas, SBPresponse, %SBPresponse and HRpeak were not different. There were no significant differences in the post-exercise SBP and HR responses of males and females except for SBP3, SBP4, HR3 and HR4. After adjusting for exercise duration, body mass index (BMI), and resting SBP and HR, these variables became similar. Sex differences in some SBP and HR responses to exercise, become nonexistent after adjusting for BMI, exercise duration, and resting SBP and HR.

  16. Power to identify a genetic predictor of antihypertensive drug response using different methods to measure blood pressure response

    Directory of Open Access Journals (Sweden)

    Turner Stephen T

    2012-03-01

    Full Text Available Abstract Background To determine whether office, home, ambulatory daytime and nighttime blood pressure (BP responses to antihypertensive drug therapy measure the same signal and which method provides greatest power to identify genetic predictors of BP response. Methods We analyzed office, home, ambulatory daytime and nighttime BP responses in hypertensive adults randomized to atenolol (N = 242 or hydrochlorothiazide (N = 257 in the Pharmacogenomic Evaluation of Antihypertensive Responses Study. Since different measured BP responses may have different predictors, we tested the "same signal" model by using linear regression methods to determine whether known predictors of BP response depend on the method of BP measurement. We estimated signal-to-noise ratios and compared power to identify a genetic polymorphism predicting BP response measured by each method separately and by weighted averages of multiple methods. Results After adjustment for pretreatment BP level, known predictors of BP response including plasma renin activity, race, and sex were independent of the method of BP measurement. Signal-to-noise ratios were more than 2-fold greater for home and ambulatory daytime BP responses than for office and ambulatory nighttime BP responses and up to 11-fold greater for weighted averages of all four methods. Power to identify a genetic polymorphism predicting BP response was directly related to the signal-to-noise ratio and, therefore, greatest with the weighted averages. Conclusion Since different methods of measuring BP response to antihypertensive drug therapy measure the same signal, weighted averages of the BP responses measured by multiple methods minimize measurement error and optimize power to identify genetic predictors of BP response.

  17. 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.

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

    OpenAIRE

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

    2015-01-01

    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) ...

  19. 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.

  20. Effects of ion concentration and natural organic matter on arsenic(V) removal by nanofiltration under different transmembrane pressures

    Institute of Scientific and Technical Information of China (English)

    Yang Yu; Changwei Zhao; Yangui Wang; Weihong Fan; Zhaokun Luan

    2013-01-01

    The removal of As(V) from synthetic water was studied using four different nanofiltradon (NF) membranes (ESNA-1-K1,NF270,ESNA-1-LF,and HODRA-CORE).The influences of ion concentration,transmembrane pressure (TMP),and the presence of natural organic matter (humic acid,HA) on the arsenic removal efficiency and permeate flux were investigated.The arsenic rejection of ESNA-1-LP was higher than those of the other membranes in all experiments (> 94%),and the HODRA-CORE membrane gave the lowest removal of arsenic (< 47%).An increase in the ion concentration in the feed solution and addition of HA decreased the arsenic rejection of the HODRA-CORE membrane.However,both increasing of the ion concentration and addition of HA made the rejection increased for the other membranes (ESNA-1-K1,NF270,and ESNA-1-LF).With increasing TMP,for all four NF membranes,increases in both arsenic rejection and permeate flux were observed.The permeate fluxes of the four NF membranes decreased to some extent after addition of HA to the solutions for operating time of 6 hr.

  1. 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

    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 < 0.003), while neuropsychological assessment did not reveal significant differences 72 h after spinal 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. 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. PMID:27790243

  2. 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...

  3. MS2 virus inactivation by atmospheric-pressure cold plasma using different gas carriers and power levels.

    Science.gov (United States)

    Wu, Yan; Liang, Yongdong; Wei, Kai; Li, Wei; Yao, Maosheng; Zhang, Jue; Grinshpun, Sergey A

    2015-02-01

    In this study, airborne MS2 bacteriophages were exposed for subsecond time intervals to atmospheric-pressure cold plasma (APCP) produced using different power levels (20, 24, and 28 W) and gas carriers (ambient air, Ar-O2 [2%, vol/vol], and He-O2 [2%, vol/vol]). In addition, waterborne MS2 viruses were directly subjected to the APCP treatment for up to 3 min. MS2 viruses with and without the APCP exposure were examined by scanning electron microscopy (SEM), reverse transcription-PCR (RT-PCR), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Viral inactivation was shown to exhibit linear relationships with the APCP generation power and exposure time (R(2) > 0.95 for all energy levels tested) up to 95% inactivation (1.3-log reduction) after a subsecond airborne exposure at 28 W; about the same inactivation level was achieved for waterborne viruses with an exposure time of less than 1 min. A larger amount of reactive oxygen species (ROS), such as atomic oxygen, in APCP was detected for a higher generation power with Ar-O2 and He-O2 gas carriers. SEM images, SDS-PAGE, and agarose gel analysis of exposed waterborne viruses showed various levels of damage to both surface proteins and their related RNA genes after the APCP exposure, thus leading to the loss of their viability and infectivity.

  4. Fatigue Behavior of Ultrafine-Grained Medium Carbon Steel with Different Carbide Morphologies Processed by High Pressure Torsion

    Directory of Open Access Journals (Sweden)

    Christoph Ruffing

    2015-05-01

    Full Text Available The increased attention ultrafine grained (UFG materials have received over the last decade has been inspired by their high strength in combination with a remarkable ductility, which is a promising combination for good fatigue properties. In this paper, we focus on the effect of different carbide morphologies in the initial microstructure on the fatigue behavior after high pressure torsion (HPT treatment of SAE 1045 steels. The two initial carbide morphologies are spheroidized as well as tempered states. The HPT processing increased the hardness of the spheroidized and tempered states from 169 HV and 388 HV to a maximum of 511 HV and 758 HV, respectively. The endurance limit increased linearly with hardness up to about 500 HV independent of the carbide morphology. The fracture surfaces revealed mostly flat fatigue fracture surfaces with crack initiation at the surface or, more often, at non-metallic inclusions. Morphology and crack initiation mechanisms were changed by the severe plastic deformation. The residual fracture surface of specimens with spheroidal initial microstructures showed well-defined dimple structures also after HPT at high fatigue limits and high hardness values. In contrast, the specimens with a tempered initial microstructure showed rather brittle and rough residual fracture surfaces after HPT.

  5. The effect of three different methods of adding O2 additive on O concentration of atmospheric pressure plasma jets (APPJs)

    Science.gov (United States)

    Yue, Y.; Xian, Y.; Pei, X.; Lu, X.

    2016-12-01

    In order to maximize the O concentration generated by the atmospheric pressure plasma jets (APPJs), several different methods of adding O2 additive to working gas have been proposed. However, it is not clear, which method is capable of generating the highest concentration of O atom. In this paper, the concentration of O atoms in an APPJs by adding O2 to (1) the working gas, to (2) the downstream inside the tube, and (3) to the shielding gas is investigated by two-photon absorption laser-induced fluorescence spectrometry. The results clearly demonstrate that the highest O density is achieved when 1.5% of O2 is added to the working gas rather than the other two methods. In other words, the most effective way to generate O atoms is by premixing O2 with the working gas. Further investigation suggests that O atoms are mainly generated around the electrode region, where the electric field is highest. In addition, when O2 is added to the working gas, if in the meantime extra O2 is added to the downstream inside the tube, a significant decrease of O density is observed.

  6. Uncertainty of spatial distributions of soil magnetic susceptibility in areas of different type of land cover and anthropogenic pressure

    Science.gov (United States)

    Zawadzki, Jaroslaw; Fabijańczyk, Piotr

    2016-04-01

    There is still a high interest in the improvement of soil magnetometry procedures that would increase its accuracy. Soil magnetometry is usually used as a fast screening method that is used to assess the degree of soil pollution. As the magnetometric measurements do not provide the exact information about the concentration of elements in soil, it is very important to determine the uncertainty of the spatial distributions of soil magnetic susceptibility. The goal of this study was to analyze and present geostatistical methods of assessing the uncertainty of spatial distribution of soil magnetic susceptibility in areas of different land cover and anthropogenic pressure. In particular, spatial distributions of magnetic susceptibility measured on the soil surface using a MS2D Bartington device were calculated using indicator methods that make it possible to calculate the probability of exceeding the critical levels of soil magnetic susceptibility. Measurements were performed in areas located in the Upper Silesian Industrial Area in Poland, and in Norway. In these areas soil magnetic susceptibility was measured on the soil surface using a MS2D Bartington device. Additionally, soil samples were taken in order to perform chemical measurements that included the determination of a concentration of selected elements. Acknowledgment The research leading to these results has received funding from the Polish-Norwegian Research Programme operated by the National Centre for Research and Development underthe Norwegian Financial Mechanism 2009-2014 in the frame of Project IMPACT - Contract No Pol-Nor/199338/45/2013.

  7. How can the pressure in anti-embolism stockings be maintained during use? Laboratory evaluation of simulated 'wear' and different reconditioning protocols.

    Science.gov (United States)

    Macintyre, Lisa; Stewart, Hazel; Rae, Michelle

    2016-12-01

    Deep vein thrombosis is a major global health issue, responsible for thousands of deaths each year. While thrombi can form under a variety of circumstances, lack of mobility significantly increases risk and therefore non-ambulant patients are frequently fitted with anti-embolism stockings on admission to hospital, to aid blood flow, prevent pooling and thus clotting. Anti-embolism stockings are the most widely used non-invasive medical device on the market and are believed to reduce the risk of deep vein thrombosis by 40%. Despite their widespread use in hospitals world-wide, there is remarkably little research addressing their use or reconditioning and a wide variety of different reconditioning protocols are used in hospitals. The objective of this study was to establish the impact of different wear and reconditioning protocols on the pressure delivering ability of anti-embolism stockings. A laboratory investigation was undertaken to evaluate the pressure delivering ability of 2 major global brands of anti-embolism stockings over 5-8days of simulated wear (extension on static cylinders) and 4 different reconditioning protocols. 1 set of samples was continuously 'worn' for 8days without reconditioning, 1 set of samples was 'worn' for 5days with a day of relaxation between each day of 'wear', 1 set was 'hand washed' and 1 set was machine washed and then allowed to relax between each day of 'wear'. The pressure was measured at the beginning and end of each period of 'wear'. This study was undertaken in a conditioned textile testing laboratory that complies with BS EN ISO 139:2005+A1:2011. The pressure exerted by anti-embolism stockings reduced by between 15 and 24% after 24h of wear, it reduced by between 21 and 32% when worn continuously for 8days. Allowing stockings to rest for a day between days of wear allowed them to recover slightly but this recovery was only temporary. Washing stockings regenerated their pressure delivering potential significantly and machine

  8. Activity, sleep and ambient light have a different impact on circadian blood pressure, heart rate and body temperature rhythms.

    Science.gov (United States)

    Gubin, D G; Weinert, D; Rybina, S V; Danilova, L A; Solovieva, S V; Durov, A M; Prokopiev, N Y; Ushakov, P A

    2017-02-16

    The aim of the present study was to investigate the impact of endogenous and exogenous factors for the expression of the daily rhythms of body temperature (BT), blood pressure (BP) and heart rate (HR). One hundred and seventy-three young adults (YA), 17-24 years old (y.o.), of both genders were studied under a modified constant-routine (CR) protocol for 26 h. Participants were assigned randomly to groups with different lighting regimens: CR-LD, n = 77, lights (>400 l×) on from 09:00 to 17:00 h and off (400 l×) during the whole experimental session; CR-DD, n = 15, constant dim light (sleep from 23:00 till 07:00 h (Control) were reanalyzed. Seven-day Ambulatory Blood Pressure Monitoring (ABPM) records from 27 YA (16-38 y.o.) and BT self-measurement data from 70 YA (17-30 y.o.) taken on ≥ 3 successive days at 08:00, 11:00, 14:00, 17:00, 20:00, 23:00 and 03:00 were available. The obtained daily patterns were different between Control and CR-DD groups, due to effects of activity, sleep and light. The comparison of Control and CR-LD groups allowed the effects of sleep and activity to be estimated since the lighting conditions were similar. The activity level substantially elevated SBP, but not DBP. Sleep, on the other hand, lowered the nighttime DBP, but has no effect on SBP. HR was affected both by activity and sleep. In accordance with previous studies, these results confirm that the steep BP increase in the morning is not driven by the circadian clock, but rather by sympathoadrenal factors related to awakening and corresponding anticipatory mechanisms. The effect on BT was not significant. To investigate the impact of light during the former dark time and darkness during the former light time, the CR-LL and CR-DD groups were each compared with the CR-LD group. Light delayed the evening decrease of BT, most likely via a suppression of the melatonin rise. Besides, it had a prominent arousal effect on SBP both in the former light and dark phases, a moderate effect on

  9. 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.

  10. 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.

  11. 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%.

  12. Effect of electronic toilet system (bidet) on anorectal pressure in normal healthy volunteers: influence of different types of water stream and temperature.

    Science.gov (United States)

    Ryoo, Seungbum; Song, Yoon Suk; Seo, Mi Sun; Oh, Heung-Kwon; Choe, Eun Kyung; Park, Kyu Joo

    2011-01-01

    Although bidets are widely used in Korea, its effects on anorectal pressures have not been studied in detail in terms of the water settings used. Twenty healthy volunteers were placed on a toilet equipped with a bidet, and anorectal pressures were measured with a manometry catheter inserted into the rectum and anal canal before and after using the bidet at different water forces (40, 80, 160, 200 mN), temperatures (24°C vs 38°C), and water jet widths (narrow vs wide). The pressure at anal high pressure zone decreased from 96.1 ± 22.5 to 81.9 ± 23.3 mmHg at water jet pressure of 40 mN and 38°C wide water jet (P bidet could be used to reduce anal resting pressure in the same manner as the traditional warm sitz bath under the conditions of low or medium water jet pressure, a warm water temperature, and a wide type water jet.

  13. Experiments of Brittle-Plastic Transition and Instability Modes of Juyongguan Granite at Different Temperatures and Pressures

    Institute of Scientific and Technical Information of China (English)

    Zhou Yongsheng; Jiang Haikun; He Changrong

    2003-01-01

    Three groups of experiments on brittle-plastic transition and instability modes of granite wereperformed in a triaxial vessel with solid pressure medium at high temperature and highpressure. The results of experiments show that brittle faulting is the major failure mode attemperature < 300℃, but crystal-plastic deformation is dominate at temperature > 800℃, andthere is a transition with increasing temperature from semi-brittle faulting to cataclnstic flowand semi-brittle flow at temperatures of 300 ~ 800℃. So, temperature is the most influentialfactor in brittle-plastic transition of granite and confining pressure is the second factor. Theresults also show that progressive failure of granite occurs at lower pressure or hightemperature where there is crystal plasticity, and sudden instability occurs at room temperatureand high pressure ( > 300MPa) or high temperature and great pressure(550℃600MPa ~ 650℃700MPa), and a broad regime of quasi-sudden instability exists between the T-P condition ofprogressive failure and sudden instability. So, instability modes of granite dependsimnitaneonsly on the pressure and temperature.

  14. [Change of ambulatory blood pressure-related parameters for different levels of renal function in resistant hypertension].

    Science.gov (United States)

    Kong, Yu; Li, Hang; Yu, Zhenqiu; Yang, Geng

    2015-03-24

    To explore the predictive values of ambulatory blood pressure-related parameters for moderate renal impairment in resistant hypertension (RH). The clinical data were retrospectively analyzed for 401 hospitalized patients with hypertension at our hospital from October 2010 to October 2013. They were divided into RH (n = 263) and non-RH (n = 138). The modified estimating equation of glomerular filtration rate (GFR) for Chinese patients was used to assess renal functions. The standardization of moderate renal impairment was when GFR below 60 ml · min⁻¹ · 1.73 m⁻². The ambulatory blood pressure-related parameters were obtained by 24 h ambulatory blood pressure monitoring. The important prediction of these parameters for moderate renal impairment was accessed by receiver operating characteristic (ROC) curve. And the related risk factors for renal function impairment were tested by multiple stepwise Logistic regression analysis. Ambulatory arterial stiffness index (AASI), 24 h mean pulse pressure (24 hPP), sleeptime relative systolic blood pressure (SBP) decline and 24 h systolic blood pressure (24 hSBP) had important predictive values for moderate renal impairment in RH. GFR was significantly lower in those with AASI ≥ 0.485, 24 hPP ≥ 47.5 mmHg, sleeptime relative SBP decline ≤ -1.75% and 24 hSBP ≥ 130.5 mmHg (P resistant hypertension.

  15. Effects of 4-week administration of simvastatin in different doses on heart rate and blood pressure after metoprolol injection in normocholesterolaemic and normotensive rats.

    Science.gov (United States)

    Owczarek, Jacek; Jasińska, Magdalena; Wejman, Irena; Kurczewska, Urszula; Orszulak-Michalak, Daria

    2012-02-29

    Statins and β1-adrenergic antagonists are well established in cardiovascular events therapy and prevention. The previous study showed that statins might impact on β-adrenergic signalling and blood pressure in a dose-dependent manner. The aim of the study was to evaluate the impact of 4-week administration of simvastatin given at different doses on the heart rate and blood pressure after injection of metoprolol in rats. The experiments were performed in normocholesterolaemic and normotensive Wistar rats. Rats received simvastatin in doses of 1, 10 and 20 mg/kg body weight (bw) for 4 weeks. The control group received 0.2% methylcellulose. For the further estimation of the heart rate and blood pressure, metoprolol at 5 mg/kg bw or 0.9% NaCl was injected intraperitoneally. Simvastatin at doses of 1, 10 and 20 mg/kg bw did not influence the heart rate or blood pressure as compared to the control group. Metoprolol injection statistically significantly decreased the heart rate (439.29±14.03 min(-1) vs. 374.41±13.32 min(-1); pheart rate and blood pressure (mean, systolic, diastolic) were similar as compared to the group receiving metoprolol alone. Simvastatin administration during a 4-week period in different doses did not influence the heart rate or blood pressure after metoprolol injection in normocholesterolaemic and normotensive rats.

  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

    and the temperatures range from 2 to 95 °C, differing for the specimen types. The data has been analyzed to yield differential enthalpy and entropy of adsorption, as well as the dependence of the relative vapor pressure on temperature at various constant moisture contents. The implications for the coefficient......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...

  17. 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.

  18. 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.

  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. Associations of Blood Pressure, Sunlight, and Vitamin D in Community-Dwelling Adults: The Reasons for Geographic and Racial Differences in Stroke (Regards) Study

    Science.gov (United States)

    Rostand MD, Stephen G.; Mcclure, Leslie A.; Kent, Shia T.; Judd, Suzanne E.; Gutiérrez MD, Orlando M.

    2017-01-01

    Background Vitamin D deficiency/insufficiency is associated with hypertension. Blood pressure and circulating vitamin D concentrations vary with the seasons and distance from the equator suggesting blood pressure varies inversely with the sunshine available (insolation) for cutaneous vitamin D photosynthesis. Methods To determine if the association between insolation and blood pressure is partly explained by vitamin D we evaluated 1104 participants in the Reasons for Racial and Geographic Differences in Stroke (REGARDS) study whose blood pressure and plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured. Results We found a significant inverse association between systolic blood pressure (SBP) and 25(OH)D concentration and an inverse association between insolation and blood pressure in unadjusted analyses. After adjusting for other confounding variables, the association of solar insolation and blood pressure was augmented,-0.3.5±SE 0.01 mmHg/1SD higher solar insolation, p=0.01. We found the greatest of effects of insolation on SBP were observed in whites (-5.2±SE O.92 mmHg/1SD higher solar insolation, p=0.005) and in women (-3.8±SE 1.7 mmHg, p=0.024). We found that adjusting for 25(OH)D had no effect on the association of solar insolation with SBP. Conclusions We conclude that although 25(OH)D concentration is inversely associated with SBP, 25(OH)D it did not explain the association of greater sunlight exposure with lower blood pressure. Condensed Abstract To determine if the inverse association between solar insolation and blood pressure is partly explained by vitamin D we evaluated 1104 participants in the Reasons for Racial and Geographic Differences in Stroke (REGARDS) study whose blood pressure and plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured. We found that 25(OH)D concentration varied inversely with SBP and SBP varied inversely with solar insolation but we found that adjusting for 25(OH)D had no effect on the association of

  1. 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.

  2. Standard Test Method for Water Penetration of Flat Plate Solar Collectors by Uniform Static Air Pressure Difference

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1986-01-01

    1.1 This test method covers the determination of the resistance of flat plate solar collectors to water penetration when water is applied to their outer surfaces with a static air pressure at the outer surface higher than the pressure at the interior of the collector. 1.2 This test method is applicable to any flat plate solar collector. 1.3 The proper use of this test method requires a knowledge of the principles of pressure and deflection measurement. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary information is contained in Section 6.

  3. 不同压力作用形式对大鼠压疮缺血再灌注损伤的影响%Effects of Different Pressure Forms on Pressure Ulcer Ischemia-reperfusion Injury

    Institute of Scientific and Technical Information of China (English)

    梁燕; 薛燕; 侯冉; 王海芳

    2012-01-01

    Objective To discuss the effects of different pressure forms (vertical pressure, friction and shear force)on pressure ulcers, so as to integrate them into pressure ulcer risk factors assessment scale and give corresponding theoretical basis for the score. Methods Thirty-two SD rats were randomly divided into four groups: control group (group A), vertical pressure group (group B), friction group (group C) and shear force group(group D). Then a rat pressure ulcer ischemia-reperfusion model was established. Macroscopic observation was conducted on rat skin integrity and color changes of pressure parts,which was followed by determination of serum superoxide dismutase(SOD) activity,malondialdehyde (MDA) and nitric oxide (NO) content and the epidermis, dermis and muscle tissue. Results Except the control group, injuries were detected of the pressure areas of the other three groups by the naked eye and microscopic observation. Muscle damage in the shear force group was more significant than that in the vertical pressure group; skin damage in the friction group was more significant than that in the vertical pressure group. The levels of SOD and NO significantly decreased and the level of MDA significantly increased in the friction group and shear force group, compared with the control group and vertical pressure group(P<0. 01 or P< 0. 05). Conclusion The vertical pressure,friction and shear force can be integrated into pressure ulcer risk factors assessment scale,with progressive scale scores.%目的 探讨不同压力作用形式(垂直压力、摩擦力和剪切力)对压疮的影响,为其纳入压疮危险因素评估表并给予相应分值提供实验依据.方法 将32只远交群大鼠(sprague dawley,SD)按随机数字表法分为4组:对照组(A组)、垂直压力组(B组)、摩擦力组(C组)和剪切力组(D组),建立大鼠压疮缺血再灌注模型.肉眼观察大鼠受压部位皮肤完整性和颜色变化,测定血清中超氧化物歧化酶(SOD)的活性

  4. Impact of different dietary approaches on blood pressure in hypertensive and prehypertensive patients: protocol for a systematic review and network meta-analysis

    Science.gov (United States)

    Schwingshackl, Lukas; Chaimani, Anna; Hoffmann, Georg; Schwedhelm, Carolina; Boeing, Heiner

    2017-01-01

    Introduction Lifestyle modification is one of the cornerstones in the management of hypertension. According to the most recent guidelines by the American Heart Association, all patients with hypertension should adopt the following dietary advices: increased consumption of fresh fruits, vegetables, low-fat dairy products and sodium reduction. The aim of the present study is to assess the efficacy of different dietary approaches on systolic and diastolic blood pressure in patients with hypertension and high normal blood pressure in a systematic review including a pairwise and network meta-analysis of randomised trials. Methods and analysis We conducted searches in Cochrane Central Register of Controlled Trials in the Cochrane Library, PubMed and Google Scholar until November 2016. Citations, abstracts and relevant papers were screened for eligibility by two reviewers independently. Randomised trials were included if they met the following criteria: (1) hypertension (as mean values ≥140 mm Hg systolic blood pressure and/or ≥90 mm Hg diastolic blood pressure) or high normal blood pressure (mean systolic blood pressure ≥130 mm Hg and/or mean diastolic blood pressure ≥85 mm Hg), (2) age ≥18 years, (3) intervention diets (different type of dietary approaches, eg, dietary approach to stop hypertension diet; Mediterranean diet, vegetarian diet, palaeolithic diet, low sodium diet) either hypocaloric, isocaloric or ad libitum diets, (4) intervention period ≥12 weeks. For each outcome measure of interest, random effects pairwise and network meta-analyses were performed in order to determine the pooled relative effect of each intervention relative to every other intervention in terms of the postintervention values (or change scores). Subgroup analyses were planned for hypertensive status, study length, sample size, age and sex. Ethics and dissemination As this study is based solely on the published literature, no ethics approval was required. We published

  5. Impact of two-way air flow due to temperature difference on preventing the entry of outdoor particles using indoor positive pressure control method.

    Science.gov (United States)

    Chen, Chun; Zhao, Bin; Yang, Xudong

    2011-02-28

    Maintaining positive pressure indoors using mechanical ventilation system is a popular control method for preventing the entry of outdoor airborne particles. The idea is, as long as the supply air flow rate is larger than return air flow rate, the pressure inside the ventilated room should be positive since the superfluous air flow must exfiltrate from air leakages or other openings of the room to the outdoors. Based on experimental and theoretical analyses this paper aims to show the impact of two-way air flow due to indoor/outdoor temperature difference on preventing the entry of outdoor particles using positive pressure control method. The indoor positive pressure control method is effective only when the size of the opening area is restricted to a certain level, opening degree less than 30° in this study, due to the two-way air flow effect induced by differential temperature. The theoretical model was validated using the experimental data. The impacts of two-way air flow due to temperature difference and the supply air flow rate were also analyzed using the theoretical model as well as experimental data. For real houses, it seems that the idea about the positive pressure control method for preventing the entry of outdoor particles has a blind side.

  6. Experimental measurement of the electrical conductivity of single crystal olivine at high temperature and high pressure under different oxygen fugacities

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    At 1.0-4.0 GPa and 1123-1473 K and under oxygen fugacity-controlled conditions (Ni + NiO, Fe + Fe3O4, Fe +FeO and Mo + MoO2 buffers), a YJ-3000t Model six-anvil solid high-pressure apparatus and a Sarltron-1260 Impedance/Gain-Phase analyzer were employed to conduct an in situ measurement of the electrical conductivity of single crystal olivine. Experimental results showed that: (1) within the range of experimentally selected frequencies (103-106 Hz), the electrical conductivity of the sample is of great dependence on the frequency; (2) with the rise of temperature (T), the electrical conductivity (σ) will increase, and the Arrenhius linear relationship is established between lgσ and 1/T; (3) under the control of oxygen buffer Fe + Fe3O4, with the rise of pressure, the electrical conductivity tends to decrease whereas the activation enthalpy and independent-of-temperature preexponential factor tend to increase,with the activation energy and activation volume of the sample estimated at ( 1.25 ± 0.08) eV and (0. 105 ± 0. 025) cm3/mol, respectively; (4) under given pressure and temperature conditions, the electrical conductivity tends to increase whereas the activation energy tends to decrease with increasing oxygen fugacity; and (5) the mechanism of electrical conduction of small polarons can provide insight into the behavior of electrical conduction of olivine under high pressure and high temperature.

  7. Comparing intra-abdominal pressures in different body positions via a urinary catheter and nasogastric tube: a pilot study.

    Science.gov (United States)

    Rooban, Nirooshan; Regli, Adrian; Davis, Wendy A; De Keulenaer, Bart L

    2012-07-05

    Intra-abdominal pressure (IAP) is most commonly measured via the bladder with the patient in the supine position. In the ICU, patients are nursed with the head of the bed elevated at 30° (HOB30) to reduce the risk of ventilator-associated pneumonia. This study investigated whether gastric pressure at HOB30 can be used as a surrogate measure of IAP via the bladder in the supine position. A prospective observational study was conducted in a single-centre intensive care unit. A total of 20 patients were included. IAP was recorded simultaneously via the bladder catheter (bladder pressure, IBP) and via nasogastric tube (gastric pressures, IGP) in the supine and HOB30 position. Each patient had three sets of IAP measurements performed at least 4 h apart. In the supine position, mean IBP was 12.3 ± 4.5 mmHg compared to IGP of 11.8 ± 4.7 mmHg. The bias between the two groups was 0.5 and precision of 3.7 (LA, -6.8 to 7.5 mmHg). At 30 degrees, mean IBP was 15.8 ± 4.9 mmHg compared to IGP of 13.1 ± 6.1 mmHg. The bias between both groups was 2.7 with a precision of 5.5 (LA, -8.0 to 13.5). Comparing IBP in the supine position with IGP at 30° showed a bias of -0.8 and precision of 5.6 (LA, -10.1 to 11.6 mmHg). IAP measured via a nasogastric tube was less influenced by changing the body position from supine to HOB30 than was bladder pressure.

  8. [Intrafemoral pressure measurement in different cement removal procedures during hip prosthesis replacement operations--experimental study with cadaver femora].

    Science.gov (United States)

    Porsch, M; Schmidt, J; Brimmers, P; Menne, A; Merkle, W

    1998-03-01

    During primary hip arthroplasty an increase in intramedullary pressure (IMP) of up to 1000 mm Hg can be observed. As a result of this increased intrafemoral pressure, intramedullary constituents can pass into the venous circulation creating a risk of fat embolism syndrome (FES). In the present experimental study on 9 femora obtained from human corpses, we investigated the question as to whether various methods of cement removal during total hip revision arthroplasty are also associated with increased intramedullary pressure and a risk of FES. The IMP was recorded with a standardized experimental set-up during removal of cement from the proximal and distal regions, including removal of the cement "tip" and the intramedullary plug. The methods employed for this purpose included the osteotome and mallet, a compressed air powered chisel, and a modified intracorporal lithotripter. All the methods induced fluctuations in the IMP the highest values being recorded for the conventional method using the osteotome and mallet (45 mm Hg) and the lowest values for the intracorporeal lithotripter (7.5 mm Hg). Working on the distal cement caused higher fluctuations in comparison with the proximal region. The study failed to reveal any increase in mean IMP, and all measured values were in the low pressure range (considerably below 150 mm Hg). While there seems to be no apparent risk of an FES developing during removal of cement, careless manipulation of the distal cement plug may result in higher intrafemoral pressures--above 150 mm Hg--thus increasing the risk of a fat embolism syndrome.

  9. The effect of different atmospheric ozone partial pressures on photosynthesis and growth of nine fruit and nut tree species.

    Science.gov (United States)

    Retzlaff, W A; Williams, L E; DeJong, T M

    1991-01-01

    Nursery stock of peach (Prunus persica L. Batsch, cv. O'Henry), nectarine (P. persica L. Batsch, cv. Fantasia), plum (P. salicina Lindel., cv. Casselman), apricot (P. armeniaca L., cv. Tilton), almond (P. dulcis Mill., cv. Nonpareil), prune (P. domestica L., cv. Improved French), cherry (P. avium L., cv. Bing), oriental pear (Pyrus pyrifolia Rehd., cv. 20th Century), and apple (Malus pumula Mill., cv. Granny Smith) were planted in open-top chambers on April 1, 1988 at the University of California's Kearney Agricultural Center located in the San Joaquin Valley (30 degrees 40' N 119 degrees 40' W). Trees were exposed to three atmospheric ozone partial pressures (charcoal-filtered air (C), ambient air (A), or ambient air + ozone (T)) from August 1 to November 17, 1988. The mean 12-h (0800 to 2000 h) ozone partial pressures measured in open-top chambers during the experimental period were 0.030, 0.051, and 0.117 microPa Pa(-1) in the C, A and T treatments, respectively. Leaf net CO(2) assimilation rate decreased linearly with increasing 12-h mean ozone partial pressure for the almond, plum, apricot, prune, pear, and apple cultivars. Stomatal conductances of apricot, apple, almond, and plum decreased linearly with increasing ozone partial pressure. Cross-sectional area relative growth rates of almond, plum, apricot, and pear decreased linearly with increasing ozone partial pressure. Net CO(2) assimilation rate, stomatal conductance, and trunk growth of cherry, peach and nectarine were unaffected by the ozone treatments. Reduced leaf gas exchange probably contributed to ozone-induced growth reduction of the susceptible species and cultivars. Several of the commercial fruit tree species and cultivars studied were relatively tolerant to the ozone treatments.

  10. Temperature Fields of Al{sub 2}O{sub 3}/MgF{sub 2} HR Coatings Prepared at Different Working Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhan Meiqiong; Wu Zhonglin, E-mail: hbzmq@126.com [Shanghai second polytechnic university, No.2360 Jinhai Road, Shanghai (China)

    2011-02-01

    A series of samples were deposited by electron beam evaporation using the same deposition process at different working pressure. Transmittance of the HR coatings was measured by Lambda 900 spectrometer. Laser-induced damage threshold (LIDT) was measured by a 355 nm Nd:YAG laser with a pulse width of 7 ns. The LIDT results range from 2.69 J/cm{sup 2} to 11.03 J/cm{sup 2} with the working pressure changing. It was found that working pressure has important effects on the absorption and LIDT of 355nm Al{sub 2}O{sub 3}/MgF{sub 2} HR coatings. The temperature rise of HR coatings under laser irradiation was calculated by interfaces absorption model based on the theory of temperature fields. The results of temperature fields agree with the results of LIDT.

  11. Optimal frequency selection of multi-channel O2-band different absorption barometric radar for air pressure measurements

    Science.gov (United States)

    Lin, Bing; Min, Qilong

    2017-02-01

    Through theoretical analysis, optimal selection of frequencies for O2 differential absorption radar systems on air pressure field measurements is achieved. The required differential absorption optical depth between a radar frequency pair is 0.5. With this required value and other considerations on water vapor absorption and the contamination of radio wave transmission, frequency pairs of present considered radar system are obtained. Significant impacts on general design of differential absorption remote sensing systems are expected from current results.

  12. Homogenous nucleation rates of n-propanol measured in the Laminar Flow Diffusion Chamber at different total pressures

    Science.gov (United States)

    Görke, Hanna; Neitola, Kimmo; Hyvärinen, Antti-Pekka; Lihavainen, Heikki; Wölk, Judith; Strey, Reinhard; Brus, David

    2014-05-01

    Nucleation rates of n-propanol were investigated in the Laminar Flow Diffusion Chamber. Nucleation temperatures between 270 and 300 K and rates between 100 and 106 cm-3 s-1 were achieved. Since earlier measurements of n-butanol and n-pentanol suggest a dependence of nucleation rates on carrier gas pressure, similar conditions were adjusted for these measurements. The obtained data fit well to results available from literature. A small positive pressure effect was found which strengthen the assumption that this effect is attributed to the carbon chain length of the n-alcohol [D. Brus, A. P. Hyvärinen, J. Wedekind, Y. Viisanen, M. Kulmala, V. Ždímal, J. Smolík, and H. Lihavainen, J. Chem. Phys. 128, 134312 (2008)] and might be less intensive for substances in the homologous series with higher equilibrium vapor pressure. A comparison with the theoretical approach by Wedekind et al. [Phys. Rev. Lett. 101, 12 (2008)] shows that the effect goes in the same direction but that the intensity is much stronger in experiments than in theory.

  13. 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.

    2017-02-01

    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.

  14. 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

  15. 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.

  16. 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

  17. Surface recrystallization of a Ni_3Al based single crystal superalloy at different annealing temperatures and blasting pressure

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The effects of annealing temperature and grit blasting pressure on the recrystallization behavior of a Ni3Al based single crystal superalloy were studied in this work. The results show that the precipitation of the Y-NiMo phase occurs at 900 and 1000 °C, which precedes recrystallization. The initial recrystallization temperature was between 1000 and 1100 °C. Cellular recrystallization was formed at 1100 and 1200 °C, which consisted of large columnar γ′ and fine γ + γ′. The dendrite arm closed to the interde...

  18. Surface tension and its temperature coefficient of molten tin determined with the sessile drop method at different oxygen partial pressures.

    Science.gov (United States)

    Yuan, Zhang Fu; Mukai, Kusuhiro; Takagi, Katsuhiko; Ohtaka, Masahiko; Huang, Wen Lai; Liu, Qiu Sheng

    2002-10-15

    The surface tension of molten tin has been determined by the sessile drop method at temperatures ranging from 523 to 1033 K and in the oxygen partial pressure (P(O(2))) range from 2.85 x 10(-19) to 8.56 x 10(-6) MPa, and its dependence on temperature and oxygen partial pressure has been analyzed. At P(O(2))=2.85 x 10(-19) and 1.06 x 10(-15) MPa, the surface tension decreases linearly with the increase of temperature and its temperature coefficients are -0.151 and -0.094 mN m(-1) K(-1), respectively. However, at high P(O(2)) (3.17 x 10(-10), 8.56 x 10(-6) MPa), the surface tension increases with the temperature near the melting point (505 K) and decreases above 723 K. The surface tension decrease with increasing P(O(2)) is much larger near the melting point than at temperatures above 823 K. The contact angle between the molten tin and the alumina substrate is 158-173 degrees, and the wettability is poor.

  19. Angelo State Society of Physics Students Peer Pressure Team Public Engagement Efforts -- Do we make a difference?

    Science.gov (United States)

    Johnson, Jeremy; Sauncy, Toni

    2011-10-01

    The Angelo State Society of Physics Students Peer Pressure Team travels throughout West-CentralTexas for a week following the spring semester. The goals of this activity are two-fold. First the group seeks to engage undergraduate presenters in public servive; the second goal is to enhance attitudes about science and encourage students in K-12 public schools to study science. Many of the schools we choose for our outreach visits are geographically isolated and populated with socioeconomically disadvantaged students, and/or groups underrepresented in physics. Over the week, the Peer Pressure Team visited over 1300 students, teachers and administrators. At each visit, surveys were collected to gauge the program's effectiveness. Student responses indicate a strong desire to study more science in their regular school curriculum. In addition, results are used to determine which demonstrations leave the most lasting impression on the audience participants. The 2011 Road Tour was dedicated to the 100^th anniversary of the discovery of the nucleus by Rutherford.

  20. 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.

  1. Calculation of difference in heat capacities at constant pressure and constant volume with the aid of the empirical Nernst and Lindemann equation

    Science.gov (United States)

    Leontev, K. L.

    1981-07-01

    An expression is obtained for heat capacity differences of materials at a constant pressure and volume, on the basis of the rigorous thermodynamic equation (Kittel, 1976), and by using the Grueneisen law (Kikoin and Kikoin, 1976) of constancy of the ratio of the cubic expansion coefficient to the molar heat capacity. Conditions are determined, where the empirical Nernst and Lindemann (Filippov, 1967) equation is regarded as rigorous.

  2. Difference in blood pressure response to ACE-Inhibitor monotherapy between black and white adults with arterial hypertension: a meta-analysis of 13 clinical trials.

    Science.gov (United States)

    Peck, Robert N; Smart, Luke R; Beier, Rita; Liwa, Anthony C; Grosskurth, Heiner; Fitzgerald, Daniel W; Schmidt, Bernhard M W

    2013-09-26

    Among African-Americans adults, arterial hypertension is both more prevalent and associated with more complications than among white adults. Hypertension is also epidemic among black adults in sub-Saharan Africa. The treatment of hypertension among black adults may be complicated by lesser response to certain classes of anti-hypertensive agents. We systematically searched literature for clinical trials of ACE-inhibitors among hypertensive adults comparing blood pressure response between whites and blacks. Meta-analysis was performed to determine the difference in systolic and diastolic blood pressure response. Further analysis including meta-regressions, funnel plots, and one-study-removed analyses were performed to investigate possible sources of heterogeneity or bias. In a meta-analysis of 13 trials providing 17 different patient groups for evaluation, black race was associated with a lesser reduction in systolic (mean difference: 4.6 mmHg (95% CI 3.5-5.7)) and diastolic (mean difference: 2.8 mmHg (95% CI 2.2-3.5)) blood pressure response to ACE-inhibitors, with little heterogeneity. Meta-regression revealed only ACE-inhibitor dosage as a significant source of heterogeneity. There was little evidence of publication bias. Black race is consistently associated with a clinically significant lesser reduction in both systolic and diastolic blood pressure to ACE-inhibitor therapy in clinical trials in the USA and Europe. In black adults requiring monotherapy for uncomplicated hypertension, drugs other than ACE-inhibitors may be preferred, though the proven benefits of ACE-inhibitors in some sub-groups and the large overlap of response between blacks and whites must be remembered. These data are particularly important for interpretation of clinical drug trials for hypertensive black adults in sub-Saharan Africa and for the development of treatment recommendations in this population.

  3. 不同年资临床护士的足底压力步态分析%Analysis on Plantar Pressure of Clinical Nurses with Different Seniorities

    Institute of Scientific and Technical Information of China (English)

    王彦斐; 程如意

    2014-01-01

    目的:评估不同年资护士的步态。方法:采用足底压力分布测试系统分别对工作1年以内和10年以上各24名护士进行动态足底压力测试。结果:所有护士的足部最大压强都在2、3跖骨区,最大冲量在前足。同一名护士,其早晨上班时的足底压力压强与下午下班时的足底压力压强有明显差异(P<0.05)。下午时压力压强冲量明显高于早晨(P<0.05)。年资高的护士压力压强冲量明显高于年资低的护士(P<0.05)。结论:护士的职业特点使其足底压力压强相对较高,易造成足部损伤。%Objective:To assess the gaits of the nurses with different seniorities. Methods: Dynamic plantar pressure of 24 nurses who have worked less than one year or more than ten years were measured by plantar pressure distribution measurement system respectively. Results:Maximum plantar pressure of all the nurses was distributed around the second and third metatarsal bones, maximum impulse was around the anterior part of the feet. There was significant difference for the same nurse between plantar pressure and impulse in the morning and afternoon (P<0.05). Impulse and pressure in the afternoon were remarkably higher than these in the morning (P<0.05). Pressure and im-pulse of the nurse with high seniorities were higher than these of the ones with junior seniorities notably (P<0.05). Conclusion:Professional characters make the nurses suffering from higher plantar pressure and impulse, which could cause foot damage easily.

  4. 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.

  5. 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.

  6. 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.

  7. Electrical properties of InGaN thin films grown by RF sputtering at different temperatures, varying nitrogen and argon partial pressure ratios

    Science.gov (United States)

    Jakkala, Pratheesh; Kordesch, Martin E.

    2016-10-01

    Indium gallium nitride (InGaN) thin films of varying indium (In) and gallium (Ga) compositions have been fabricated on aluminosilicate glass and silicon (111) substrates using RF magnetron sputtering method at different growth temperatures, varied from 35 °C to 450 °C. Argon (Ar) and nitrogen (N2) are used as Inert and reactive gases respectively. Keeping the total pressure of gas mixture constant, partial pressures of N2 and Ar gases are varied. Ratio of Ar partial pressure to total pressure in the gas mixture is varied from 0 to 0.75. In this study, we present electrical properties of these InGaN thin films. Resistivity values of 2.6 × 10-5 to 1.68 × 10-2 Ω.cm, mobility values of 0.119 to 45.2 cm2/V.s, conductivity values of 0.595 × 103 to 37.3 × 103 mho/cm and bulk carrier concentration values -1020 to -1022/m3 are recorded that are measured through Hall-effect measurement technique.

  8. Supercooling of aqueous dimethylsulfoxide solution at normal and high pressures: Evidence for the coexistence of phase-separated aqueous dimethylsulfoxide solutions of different water structures.

    Science.gov (United States)

    Kanno, H; Kajiwara, K; Miyata, K

    2010-05-21

    Supercooling behavior of aqueous dimethylsulfoxide (DMSO) solution was investigated as a function of DMSO concentration and at high pressures. A linear relationship was observed for T(H) (homogeneous ice nucleation temperature) and T(m) (melting temperature) for the supercooling of aqueous DMSO solution at normal pressure. Analysis of the DTA (differential thermal analysis) traces for homogeneous ice crystallization in the bottom region of the T(H) curve for a DMSO solution of R=20 (R: moles of water/moles of DMSO) at high pressures supported the contention that the second critical point (SCP) of liquid water should exist at P(c2)= approximately 200 MPa and at T(c2)temperature of SCP). The presence of two T(H) peaks for DMSO solutions (R=15, 12, and 10) suggests that phase separation occurs in aqueous DMSO solution (Rtemperatures (different liquid water structures [LDL-like and HDL-like structures (LDL: low-density liquid water, HDL: high-density liquid water)] in the pressure range of 120-230 MPa.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. A longitudinal study of arterial blood pressure in chronic haemodialysis patients with different levels of plasma renin concentration.

    Science.gov (United States)

    Kornerup, H J; Fredsted, B; Pedersen, R S

    1978-01-01

    The purpose of the study was to examine the value of regular measurements of plasma renin concentration (PRC) in selecting those chronic haemodialysis patients suitable for bilateral nephrectomy to prevent development of uncontrollable hypertension. Regular measurements of arterial blood pressure (BP) and PRC were performed during one year in 31 patients undergoing regular haemodialysis because of end-stage renal disease. Among 18 patients with PRC greater than or equal to 100 micro Goldblatt units per ml plasma (microGU/ml) systolic and/or diastolic hypertension persisted or developed in 12. In contrast, among 13 patients with PRC greater than 100microGU/ml, BP became normal in all but one, who had a slightly increased systolic BP. However, hypertension was mild and easily controlled by conventional therapy in all except one, who probably had an overlying volume-dependent hypertension. Therefore, bilateral nephrectomy was not necessary in any case. The results indicate that hypertension in the majority of chronic haemodialysis patients with high PRC can be adequately controlled without surgical intervention and that regular measurements of PRC have no practical value in forecasting the development of uncontrollable hypertension in chronic haemodialysis patients.

  14. Development of wafer-level-packaging technology for simultaneous sealing of accelerometer and gyroscope under different pressures

    Science.gov (United States)

    Aono, T.; Suzuki, K.; Kanamaru, M.; Okada, R.; Maeda, D.; Hayashi, M.; Isono, Y.

    2016-10-01

    This research demonstrates a newly developed anodic bonding-based wafer-level-packaging technique to simultaneously seal an accelerometer in the atmosphere and a gyroscope in a vacuum with a glass cap for micro-electromechanical systems sensors. It is necessary for the accelerometer, with a damping oscillator, to be sealed in the atmosphere to achieve a high-speed response. As the gyroscope can achieve high sensitivity with a large displacement at the resonant frequency without air-damping, the gyroscope must be sealed in a vacuum. The technique consists of three processing steps: the first bonding step in the atmosphere for the accelerometer, the pressure control step and the second bonding step in a vacuum for the gyroscope. The process conditions were experimentally determined to achieve higher shear strength at the interface of the packaging. The packaging performance of the accelerometer and gyroscope after wafer-level packaging was also investigated using a laser Doppler velocimeter at room temperature. The amplitude at the resonant frequency of the accelerometer was reduced by air damping, and the quality factor of the gyroscope showed a value higher than 1000. The reliability of the gyroscope was also confirmed by a thermal cyclic test and an endurance test at high humidity and high temperature.

  15. Digestibility for dogs and cats of meat and bone meal processed at two different temperature and pressure levels*.

    Science.gov (United States)

    de-Oliveira, L D; de Carvalho Picinato, M A; Kawauchi, I M; Sakomura, N K; Carciofi, A C

    2012-12-01

    This study evaluated the effect of two rendering processes applied to meat and bone meal (MBM) production, associated or not with extrusion, by measuring diet apparent total tract digestibility of dogs and cats, and true digestibility of amino acids (AA) by cecectomized roosters. Four diets were evaluated, with the main protein source as follows: conventional and extruded MBM; high temperature and pressure (HPT; 135 °C, 3 bar, 20 min) and extruded MBM; conventional non-extruded MBM; HPT non-extruded MBM. Nutrient digestibility and food metabolizable energy content were evaluated with dogs and cats by the method of total collection of faeces. True AA digestibility was evaluated by a precision-fed assay with cecectomized roosters. The evaluated MBM had high-ash content. The HPT process of MBM increased the digestibility of crude protein of the diets by cats, and the true digestibility of several AA by cecectomized roosters. The extrusion process did not modify the apparent total tract nutrient digestibility of MBM by dogs and their amino acid digestibility by roosters, but increased the digestibility of the dietary protein by cats. Dogs fed HPT MBM presented a higher urea post-prandial response, suggesting reductions in bioavailability and protein synthesis from absorbed AA.

  16. Intraluminal pressure, transmucosal potential difference, and pH studies in the oesophagus of patients before and after Collis repair of a hiatal hernia

    Science.gov (United States)

    Habibulla, K. S.; Collis, J. Leigh

    1973-01-01

    Intraluminal pressure, transmucosal potential difference, and endo-oesophageal pH measurements were studied in patients with hiatal hernia—before and after a hiatal repair. The operation employed is the Collis (1968) repair for uncomplicated hiatal hernia and does not refer to gastroplasty as recommended for peptic stricture (Collis, 1961). Postoperative studies show that the repair approximates the inferior oesophageal sphincter to the hiatus with the production of a single band of raised pressure at the lower end of the oesophagus. This band is similar to that seen in normal subjects and its appearance was associated with cure of the symptoms, abolition of the gastro-oesophageal reflux, and improvement in the function of the inferior oesophageal sphincter and the musculature of the body of the oesophagus. Certain physiological implications of this study are discussed. Images PMID:4724501

  17. 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.

  18. 漏斗倾角对粮仓侧压力的影响%Wall Pressure of the Granary Model with Different Hopper Angle

    Institute of Scientific and Technical Information of China (English)

    张大英; 王树明; 梁醒培

    2016-01-01

    In order to study the wall pressure of the single silo with different hopper angles, three organic glass silo models with the hopper angle of 60°,45° and 30° were made, and all silos were filled with Fujian Pingtan standard sand. The static wall pressures were obtained from pressure sensors inside the silos; meanwhile, the numerical simulation method was also employed to calculate the static wall pressure and Mises stress. Then the static wall pressure of experimental, simulated and calculated values with design code formulae were analyzed, and the final comparative analysis results show that the experimental and the simulated values are respectively in consistent with the formula calculation ( the coefficient is k and k′) , and the simulated values are larger than the experimental ones, therefore, it is workable to design silo with the proposed FEM method. The wall pressure and Mises stress are all affected by the hopper angle. The maximum of absolute differences of wall pressures appears at the bottom of silo models with the hopper angle of 30 ° and 60 ° , and the minimum appears at 0. 4 m for each silo model. It can be roughly divided into three stages to rank wall pressure values for each silo model, but the values of the silo model of 45° is always in the middle of them. Furthermore, the larger Mises stress distribution of the silo model of 30° is different from the other two silo models.%为研究不同漏斗倾角立筒仓侧压力,制作了倾角分别为60°、45°和30°的三个有机玻璃立筒仓模型,模型内装满福建平潭标准砂。根据仓壁内表面压力传感器测试得到了静态侧压力,同时,利用数值模拟方法计算得到了立筒仓静态侧压力和Mises应力。通过对比分析侧压力试验值、模拟值及规范公式计算值,结果表明:试验值和模拟值分别与侧压力系数取k和k′时的公式计算值相一致,模拟值大于试验值,可以按照模拟方法进行筒仓结

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Bae; Park, Chang Yong [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2017-05-15

    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{sub F}1{sup /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{sub F}1{sup /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.

  20. 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.

  1. Comparative immediate effect of different yoga asanas on heart rate and blood pressure in healthy young volunteers

    Directory of Open Access Journals (Sweden)

    Ananda Balayogi Bhavanani

    2014-01-01

    Conclusion: Our study provides initial evidence of differential cardiovascular effects of Asanas and subtle differences between right and left sided performance. Further, cardiovascular recovery is greater after the performance of the Asanas as compared to shavasan; thus, implying a better response when effort precedes relaxation.

  2. Comparison of the structural properties and residual stress of AlN films deposited by dc magnetron sputtering and high power impulse magnetron sputtering at different working pressures

    Energy Technology Data Exchange (ETDEWEB)

    Ait Aissa, K.; Achour, A., E-mail: a_aminph@yahoo.fr; Camus, J.; Le Brizoual, L.; Jouan, P.-Y.; Djouadi, M.-A.

    2014-01-01

    Aluminium nitride (AlN) films were deposited by dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) on (100) oriented silicon (Si) substrates, in Ar–N{sub 2} gas mixture, at different working pressures. The films were characterized using X-ray diffraction (XRD), profilometer and transmission electron microscopy (TEM). The effect of the sputtering pressure on the structure, the residual stress and the deposition rate of AlN films deposited by the two processes (dcMS and HiPIMS) was investigated. It was found that the deposition rate is always lower in HiPIMS compared to dcMS. The AlN films are textured along (002) direction in both cases of dcMS and HiPIMS as it is indicated by XRD measurements, with residual stresses which are more important in the case of films deposited by HiMIPS. These residual stresses decrease with the sputtering pressure increase, especially in the case of the films deposited by HiPIMS. TEM analyses have shown a local epitaxial growth of AlN on the Si substrate which would favour thermal evacuation improvement of AlN as thermal interface material. - Highlights: • Highly c-axis oriented AlN films were obtained. • dc magnetron sputtering and high power impulse magnetron sputtering (HiMIPS) were used. • Abrupt interface between AlN and silicon substrate was obtained by HiPIMS.

  3. The effect of flow rate at different pressures and temperatures on cocoa butter extracted from cocoa nib using supercritical carbon dioxide.

    Science.gov (United States)

    Asep, E K; Jinap, S; Russly, A R; Jahurul, M H A; Ghafoor, Kashif; Zaidul, I S M

    2016-05-01

    The effects of flow rate, different pressures and temperatures on cocoa butter extracted from cocoa nib using supercritical carbon dioxide (scCO2) were investigated. The yield was analyzed for total fat content, triacylglycerol (TG) profile, and fatty acid (FA) profile. Extractions were carried out at pressures of 20 and 35 MPa, temperatures of 50 and 60 °C, and CO2 flow rates of 0.5, 1, 2, 4 mL min(-1). The result shows that the yield of cocoa butter extract increased with increasing pressure, temperature, and flow rate and the optimum conditions for the maximum cocoa butter extraction were 35 MPa, 60 °C and 2 mL min(-1), repectively. TGs and FAs were found to be similar in composition to those of cocoa butter obtained by conventional methods. The lower molecular weight TGs and FAs showed higher selectivity compared to higher molecular weight TGs and FAs.

  4. Find out the Target IOP while Different Blood Pressure in Advanced Stage Glaucoma%晚期青光眼在不同血压段时靶眼压的选择

    Institute of Scientific and Technical Information of China (English)

    晏兴云; 贺平; 刘静

    2016-01-01

    目的:探讨晚期青光眼在不同血压段时病程的进展规律 ,并找出在不同血压段时的治疗靶眼压.方法:长期随访晚期青光眼患者的血压及眼压值 ,并分别做视野检查 ,通过A G IS评分法判断病程的进展.并统计出不同血压时的治疗靶眼压值.结果:随访血压越低 ,视野受损进展越快.当视野无进展时 ,血压越低 ,其随访眼压也越低.血压与目标眼压之间呈近似线性关系.结论:低血压是晚期青光眼病程中的危险因素之一.晚期青光眼患者对靶眼压的选择应根据不同血压段来选择.%Objective:To explore progress rule of advanced stage glaucoma and find out the target intraocular pressure in different blood pressure .Methods:Long term follow-up the intraocular pressure and blood pressure .Judge the course of glaucoma by AGIS .find out the target intraocular pressure in different blood pressure .Results:For the lower blood pressure ,impaired vision progress more quickly .When vision without progress ,the lower blood pressure ,the lower intraocular pressure there has been approximate linear relationship between blood pressure and the target intraocular pressure .Conclusion:Low blood pressure is one of the risk factors of adanced glaucoma progression .The target in-traocular pressure should be selected according to different blood pressure .

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

    OpenAIRE

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

    2014-01-01

    1. Understanding the demographic response of free-living animal populations to different drivers is the first step towards reliable prediction of population trends. 2. 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 difficul...

  6. Experimental Study on Surface Dielectric Barrier Discharge Plasma Actuator with Different Encapsulated Electrode Widths for Airflow Control at Atmospheric Pressure

    Science.gov (United States)

    Qi, Xiaohua; Yang, Liang; Yan, Huijie; Jin, Ying; Hua, Yue; Ren, Chunsheng

    2016-10-01

    The surface dielectric barrier discharge (SDBD) plasma actuator has shown great promise as an aerodynamic flow control device. In this paper, the encapsulated electrode width of a SDBD actuator is changed to study the airflow acceleration behavior. The effects of encapsulated electrode width on the actuator performance are experimentally investigated by measuring the dielectric layer surface potential, time-averaged ionic wind velocity and thrust force. Experimental results show that the airflow velocity and thrust force increase with the encapsulated electrode width. The results can be attributed to the distinct plasma distribution at different encapsulated electrode widths. supported by National Natural Science Foundation of China (No. 11175037), National Natural Science Foundation for Young Scientists of China (No. 11305017) and Special Fund for Theoretical Physics (No. 11247239)

  7. [Bi]:[Te] Control, Structural and Thermoelectric Properties of Flexible Bi x Te y Thin Films Prepared by RF Magnetron Sputtering at Different Sputtering Pressures

    Science.gov (United States)

    Nuthongkum, Pilaipon; Sakdanuphab, Rachsak; Horprathum, Mati; Sakulkalavek, Aparporn

    2017-07-01

    In this work, flexible Bi x Te y thin films were prepared by radio frequency (RF) magnetron sputtering using a Bi2Te3 target on polyimide substrate. The effects of sputtering pressures, which ranged between 0.6 Pa and 1.6 Pa on the [Bi]:[Te] ratio, and structural and thermoelectric properties were investigated. The [Bi]:[Te] ratio of thin film was determined by energy-dispersive spectrometry (EDS). The EDS spectra show the variation of the [Bi]:[Te] ratio as the sputtering pressure is varied. The film deposited at 1.4 Pa almost has a stoichiometric composition. The selective films with different [Bi]:[Te] ratios and sputtering pressures were characterized by their surface morphologies, crystal and chemical structures by field emission scanning electron microscopy (FE-SEM), x-ray diffraction (XRD) and Raman spectroscopy, respectively. Electrical transport properties, including carrier concentration and mobility, were measured by Hall effect measurements. Seebeck coefficients and electrical conductivities were simultaneously measured by a direct current four-terminal method (ZEM-3). The XRD and Raman spectroscopy results show a difference in microstructure between BiTe and Bi2Te3 depending on the [Bi]:[Te] ratio. Electrical conductivity and Seebeck coefficient are related to the crystal and chemical structures. The maximum power factor of the Bi2Te3 thin film is 9.5 × 10-4 W/K2 m at room temperature, and it increases to 12.0 × 10-4 W/K2 m at 195°C.

  8. Mud Pressure Difference Absorber for Drilling Strings%泥浆压差式钻柱减振器的研究

    Institute of Scientific and Technical Information of China (English)

    夏宏南; 杨明合; 刘刚

    2001-01-01

    针对现有减振器的减振元件在高温、高压的钻井条件下易疲劳损坏的缺点,设计了一种新型减振器。利用钻柱内外的循环压差施加钻压,实现了钻头与钻柱的柔性连接。以泥浆作为减振元件来吸收钻进过程中的纵向冲击振动能量,减振效果好,振动衰减快。它与普通液压式减振器的不同在于减振性能不受温度的影响,不贮存钻头所产生的冲击能量,是一种能同时起到保护钻柱和钻头并能控制钻压的减振工具。%In order to overcome the shortcoming of fatigue breakdown of conventional absorber components under high temperature and high pressure,a new absorber is designed,in which drilling mud is used as absorbing components and the circulating pressure difference from the inside and outside of a drilling string is used as bit weight.Flexible connection of bit with drilling string is realized.Drilling mud is used as absorbing components to absorb the vertical impacting energy during well drilling, in which absorbing is good and vibration damping is rapid. It differs from a common liquid-pressure absorber because its performance is not influenced by temperature and the impacting energy created by bit is not stored. It is a good absorbing tool that can protect the drilling strings and bits, as well as control the weight on bit.

  9. 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.)

  10. 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.

  11. The alveolar to arterial oxygen partial pressure difference is associated with pulmonary diffusing capacity in heart failure patients.

    Science.gov (United States)

    Morosin, Marco; Vignati, Carlo; Novi, Angela; Salvioni, Elisabetta; Veglia, Fabrizio; Alimento, Marina; Merli, Guido; Sciomer, Susanna; Sinagra, Gianfranco; Agostoni, Piergiuseppe

    2016-11-01

    In chronic heart failure (HF), the alveolar-capillary membrane undergoes a remodeling process that negatively affects gas exchange. In case of alveolar-capillary gas diffusion impairment, arterial desaturation (SaO2) is rarely observed in HF patients. At play are 3 factors: overall pulmonary diffusing capacity (assessed as lung diffusion for CO, DLCO), global O2 consumption (VO2) and alveolar (A) to arterial (a) pO2 gradient (AaDO2). In 100 consecutive stable HF patients, DLCO, resting respiratory gases and arterial blood gases were measured to determine VO2, paO2, pAO2 and AaDO2. DLCO was poorly but significantly related to AaDO2. The correlation improved after correcting AaDO2 for VO2 (p<0.001, r=0.49). Both VO2 and AaDO2 were independently associated with DLCO (p<0.001). Patients with reduced DLCO showed no differences as regards paO2 and pAO2. AaDO2/VO2 showed a higher gradient in patients with lower DLCO. AaDO2 increase and VO2 reduction allow preventing low SaO2 in HF patients with reduced DLCO. Accordingly, we suggest considering AaDO2 and VO2 combined and reporting AaDO2/VO2. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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.

  14. Shock-induced chemical reactions in titanium-silicon powder mixtures of different morphologies: Time-resolved pressure measurements and materials analysis

    Science.gov (United States)

    Thadhani, N. N.; Graham, R. A.; Royal, T.; Dunbar, E.; Anderson, M. U.; Holman, G. T.

    1997-08-01

    The response of porous titanium (Ti) and silicon (Si) powder mixtures with small, medium, and coarse particle morphologies is studied under high-pressure shock loading, employing postshock materials analysis as well as nanosecond, time-resolved pressure measurements. The objective of the work was to provide an experimental basis for development of models describing shock-induced solid-state chemistry. The time-resolved measurements of stress pulses obtained with piezoelectric polymer (poly-vinyl-di-flouride) pressure gauges provided extraordinary sensitivity for determination of rate-dependent shock processes. Both techniques showed clear evidence for shock-induced chemical reactions in medium-morphology powders, while fine and coarse powders showed no evidence for reaction. It was observed that the medium-morphology mixtures experience simultaneous plastic deformation of both Ti and Si particles. Fine morphology powders show particle agglomeration, while coarse Si powders undergo extensive fracture and entrapment within the plastically deformed Ti; such processes decrease the propensity for initiation of shock-induced reactions. The change of deformation mode between fracture and plastic deformation in Si powders of different morphologies is a particularly critical observation. Such a behavior reveals the overriding influence of the shock-induced, viscoplastic deformation and fracture response, which controls the mechanochemical nature of shock-induced solid-state chemistry. The present work in conjunction with our prior studies, demonstrates that the initiation of chemical reactions in shock compression of powders is controlled by solid-state mechanochemical processes, and cannot be qualitatively or quantitatively described by thermochemical models.

  15. Meta-analysis of the comparative effects of different classes of antihypertensive agents on brachial and central systolic blood pressure, and augmentation index.

    Science.gov (United States)

    Manisty, Charlotte H; Hughes, Alun D

    2013-01-01

    Brachial systolic blood pressure (bSBP) exceeds aortic pressure by a variable amount, and estimated central systolic blood pressure (cSBP) may be a better indicator of cardiovascular risk than bSBP. We undertook a systematic review and meta-analysis to compare the effect of single and multiple antihypertensive agents on bSBP, cSBP and augmentation index (AIx). A random effects meta-analysis was performed on 24 randomized controlled trials of antihypertensives with measurements of bSBP, cSBP and/or AIx. Separate analyses were performed for drug comparisons with or without placebo, and drug combinations. In the placebo vs. drug meta-analysis, antihypertensive therapy reduced bSBP more than cSBP and there was no statistically significant evidence of heterogeneity by drug class, although the number of individual studies was small. In placebo-adjusted drug vs. drug comparison, treatment with β-blockers, omapatrilat and thiazide diuretics lowered cSBP significantly less than bSBP (i.e. central to brachial amplification decreased), whereas other monotherapies lowered cSBP and bSBP to similar extents. Sample sizes were too small and effect estimates insufficiently precise to allow firm conclusions to be made regarding comparisons between individual drug classes. Antihypertensive combinations that included β-blockers decreased central to brachial amplification. β-Blockers increased AIx, whereas all other antihypertensive agents reduced AIx to similar extents. A reduction in central to brachial amplification by some classes of antihypertensive drug will result in lesser reductions in cSBP despite achievement of target bSBP. This effect could contribute to differences in outcomes in randomized clinical trials when β-blocker- and/or diuretic-based antihypertensive therapy are compared with other regimens. © 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  16. Evolution of different structural phases of TiO{sub 2} films with oxygen partial pressure and Fe doping and their electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Bapna, Komal [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001 (India); Choudhary, R.J., E-mail: ram@csr.res.in [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001 (India); Phase, D.M. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001 (India)

    2012-08-15

    Highlights: ► Fe doped and undoped TiO{sub 2} films are grown with varying oxygen partial pressure (OPP). ► Different structural and electrical phases of TiO{sub 2} films evolve with OPP. ► Phases obtained at different OPP are not same for films with different Fe doping. ► XPS confirms Fe is not in metal cluster form. ► Charge ordering is observed in magneli phase of Fe doped and undoped TiO{sub 2} films. -- Abstract: We have studied the influence of oxygen partial pressure (OPP; 250 mTorr–1 × 10{sup −5} Torr) and Fe doping (2 and 4 at.%) on structural and electrical properties of TiO{sub 2} thin films on LaAlO{sub 3} substrates. X-ray photoelectron spectroscopy suggests that Fe is not in metal cluster form. It is found that the evolution of the three phases; anatase, rutile and brookite of TiO{sub 2} as well as the magneli phase (Ti{sub n}O{sub 2n−1}) strongly depends on the OPP and Fe doping concentration. All the films grown at 250 mTorr show insulating behavior, whereas films grown at 1 × 10{sup −2} and 1 × 10{sup −4} Torr reveal high temperature metallic to low temperature semiconducting transition. Interestingly, films deposited at 1 × 10{sup −5} Torr reveal charge ordering, which is contributed to the magneli phase of TiO{sub 2}. The present study suggests that functionality of TiO{sub 2} thin film based devices can be tuned by properly selecting the OPP and dopant concentration.

  17. 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.

  18. Exergy analysis and performance of a counter flow Ranque-Hilsch vortex tube having various nozzle numbers at different inlet pressures of oxygen and air

    Energy Technology Data Exchange (ETDEWEB)

    Kirmaci, Volkan [Bartin University, Faculty of Engineering, Mechanical Engineering Department, 74100 Bartin (Turkey)

    2009-11-15

    An experimental investigation is made to determine the effects of the orifice nozzle number and the inlet pressure on the heating and cooling performance of the counter flow Ranque-Hilsch vortex tube when air and oxygen used as a fluid. The orifices used at these experiments are made of the polyamide plastic material. The thermal conductivity of polyamide plastic material is 0.25 W/m C. Five orifices with nozzle numbers of 2, 3, 4, 5 and 6 have been manufactured and used during the experiments. For each one of the orifices (nozzle numbers) when used with two different fluids, inlet pressures were adjusted from 150 kPa to 700 kPa with 50 kPa increments, and the exergy efficiency was determined. During the experiments, a vortex tube is used with an L/D ratio of 15, and cold mass fraction is held constant at 0.5. As a result of the experimental study, it is determined that the temperature gradient between the hot and cold fluid is decreased with increasing of the orifice nozzle number. (author)

  19. Effect of Low-Pressurized Perfusion with Different Concentration of Elastase on the Aneurysm Formation Rate in the Abdominal Aortic Aneurysm Model in Rabbits.

    Science.gov (United States)

    Nie, Maoxiao; Yan, Yunfeng; Li, Xinhe; Feng, Tingting; Zhao, Xin; Zhang, Mingduo; Zhao, Quanming

    2016-01-01

    Establishing an animal model of abdominal aortic aneurysm (AAA) is the key to study the pathogenesis and the pathophysiological features of AAAs. We investigated the effects of low-pressurized perfusion with different concentrations of elastase on aneurysm formation rate in the AAA model. Fifty male New Zealand white rabbits were randomly divided into A, B, C, D, and E groups. 10 μL of normal saline was perfused into the abdominal aorta in group A and 1 U/mL, 10 U/mL, 100 U/mL, or 200 U/mL of elastase was, respectively, perfused for the other four groups. All the animals were perfused for 7 min. Doppler ultrasound examinations of the abdominal aorta were performed before surgery and on day 14 after surgery. The rabbits were sacrificed and the perfused segment of the abdominal aorta was observed visually and after staining. The aneurysm formation rate of group A, group B, group C, group D, and group E was, respectively, 0%, 0%, 33.3%, 102.5-146.8%, and 241.5-255.2%. The survival rate of five groups was 90%, 90%, 90%, 90%, and 40%, respectively. So, we concluded that low-pressurized perfusion with 100 U/mL of elastase can effectively establish AAAs in rabbits with a high aneurysm formation rate.

  20. A relative difference in systolic blood pressure between arms by synchronal measurement and conventional cardiovascular risk factors are associated with the severity of coronary atherosclerosis.

    Science.gov (United States)

    Yamamoto, Tomohiko; Miura, Shin-Ichiro; Suematsu, Yasunori; Kuwano, Takashi; Sugihara, Makoto; Ike, Amane; Iwata, Atsushi; Nishikawa, Hiroaki; Saku, Keijiro

    2016-06-01

    It is not known the relationships between a difference in systolic blood pressure (SBP) or diastolic BP (DBP) between arms by synchronal measurement and the presence of coronary artery disease (CAD), and between a difference in BP between arms and the severity of coronary atherosclerosis. We enrolled 425 consecutive patients (M/F = 286/139, 67 ± 13 year) who were admitted to our University Hospital and in whom we could measure the absolute (|rt. BP - lt. BP|) and relative (rt. BP - lt. BP) differences in SBP and DBP using a nico PS-501(®) (Parama-Tech). We divided all patients into those who did and did not have CAD. The relative differences in SBP between arms in patients with CAD were significantly lower than those in patients without CAD. However, the relative difference in SBP between arms was not a predictor of the presence of CAD. We also divided 267 patients who underwent coronary angiography into tertiles according to the Gensini score (low, middle, and high score groups). Interestingly, the middle + high score groups showed significantly lower relative differences in SBP between arms than the low score group. The mean Korotkoff sound graph in the middle + high Gensini score group was significantly higher than that in the low Gensini score group. Among conventional cardiovascular risk factors and nico parameters, the relative difference in SBP between arms in addition to the risk factors (age, gender, body mass index, hypertension, dyslipidemia, and diabetes mellitus) was associated with the score by a logistic regression analysis. In conclusion, the relative difference in SBP between arms as well as conventional risk factors may be associated with the severity of coronary arteriosclerosis.

  1. Are fern stomatal responses to different stimuli coordinated? Testing responses to light, vapor pressure deficit, and CO2 for diverse species grown under contrasting irradiances.

    Science.gov (United States)

    Creese, Chris; Oberbauer, Steve; Rundel, Phil; Sack, Lawren

    2014-10-01

    The stomatal behavior of ferns provides an excellent system for disentangling responses to different environmental signals, which balance carbon gain against water loss. Here, we measured responses of stomatal conductance (gs ) to irradiance, CO2 , and vapor pressure deficit (VPD) for 13 phylogenetically diverse species native to open and shaded habitats, grown under high- and low-irradiance treatments. We tested two main hypotheses: that plants adapted and grown in high-irradiance environments would have greater responsiveness to all stimuli given higher flux rates; and that species' responsiveness to different factors would be correlated because of the relative simplicity of fern stomatal control. We found that species with higher light-saturated gs had larger responses, and that plants grown under high irradiance were more responsive to all stimuli. Open habitat species showed greater responsiveness to irradiance and CO2 , but lower responsiveness to VPD; a case of plasticity and adaptation tending in different directions. Responses of gs to irradiance and VPD were positively correlated across species, but CO2 responses were independent and highly variable. The novel finding of correlations among stomatal responses to different stimuli suggests coordination of hydraulic and photosynthetic signaling networks modulating fern stomatal responses, which show distinct optimization at growth and evolutionary time-scales.

  2. Vapour pressure deficit during growth has little impact on genotypic differences of transpiration efficiency at leaf and whole-plant level: an example from Populus nigra L.

    Science.gov (United States)

    Rasheed, Fahad; Dreyer, Erwin; Richard, Béatrice; Brignolas, Franck; Brendel, Oliver; Le Thiec, Didier

    2015-04-01

    Poplar genotypes differ in transpiration efficiency (TE) at leaf and whole-plant level under similar conditions. We tested whether atmospheric vapour pressure deficit (VPD) affected TE to the same extent across genotypes. Six Populus nigra genotypes were grown under two VPD. We recorded (1) (13)C content in soluble sugars; (2) (18)O enrichment in leaf water; (3) leaf-level gas exchange; and (4) whole-plant biomass accumulation and water use. Whole-plant and intrinsic leaf TE and (13)C content in soluble sugars differed significantly among genotypes. Stomatal conductance contributed more to these differences than net CO2 assimilation rate. VPD increased water use and reduced whole-plant TE. It increased intrinsic leaf-level TE due to a decline in stomatal conductance. It also promoted higher (18)O enrichment in leaf water. VPD had no genotype-specific effect. We detected a deviation in the relationship between (13)C in leaf sugars and (13)C predicted from gas exchange and the standard discrimination model. This may be partly due to genotypic differences in mesophyll conductance, and to its lack of sensitivity to VPD. Leaf-level (13)C discrimination was a powerful predictor of the genetic variability of whole-plant TE irrespective of VPD during growth. © 2014 John Wiley & Sons Ltd.

  3. A study of the effect on human mesenchymal stem cells of an atmospheric pressure plasma source driven by different voltage waveforms

    Science.gov (United States)

    Laurita, R.; Alviano, F.; Marchionni, C.; Abruzzo, P. M.; Bolotta, A.; Bonsi, L.; Colombo, V.; Gherardi, M.; Liguori, A.; Ricci, F.; Rossi, M.; Stancampiano, A.; Tazzari, P. L.; Marini, M.

    2016-09-01

    The effect of an atmospheric pressure non-equilibrium plasma on human mesenchymal stem cells was investigated. A dielectric barrier discharge non-equilibrium plasma source driven by two different high-voltage pulsed generators was used and cell survival, senescence, proliferation, and differentiation were evaluated. Cells deprived of the culture medium and treated with nanosecond pulsed plasma showed a higher mortality rate, while higher survival and retention of proliferation were observed in cells treated with microsecond pulsed plasma in the presence of the culture medium. While a few treated cells showed the hallmarks of senescence, unexpected delayed apoptosis ensued in cells exposed to plasma-treated medium. The plasma treatment did not change the expression of OCT4, a marker of mesenchymal stem cell differentiation.

  4. 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

  5. Antibacterial Activity of Cold Atmospheric Pressure Argon Plasma against 78 Genetically Different (mecA, luk-P, agr or Capsular Polysaccharide Type) Staphylococcus aureus Strains.

    Science.gov (United States)

    Matthes, Rutger; Lührman, Anne; Holtfreter, Silva; Kolata, Julia; Radke, Dörte; Hübner, Nils-Olaf; Assadian, Ojan; Kramer, Axel

    2016-01-01

    Previous studies on the antimicrobial activity of cold atmospheric pressure argon plasma showed varying effects against mecA+ or mecA-Staphylococcus aureus strains. This observation may have important clinical and epidemiological implications. Here, the antibacterial activity of argon plasma was investigated against 78 genetically different S. aureus strains, stratified by mecA, luk-P, agr1-4, or the cell wall capsule polysaccharide types 5 and 8. kINPen09® served as the plasma source for all experiments. On agar plates, mecA+luk-P-S. aureus strains showed a decreased susceptibility against plasma compared to other S. aureus strains. This study underlines the high complexity of microbial defence against antimicrobial treatment and confirms a previously reported strain-dependent susceptibility of S. aureus to plasma treatment.

  6. Microwave-assisted extraction at atmospheric pressure coupled to different clean-up methods for the determination of organophosphorus pesticides in olive and avocado oil.

    Science.gov (United States)

    Fuentes, Edwar; Báez, María E; Díaz, Juan

    2009-12-18

    An effective extraction method was devised for the determination of organophosphorus pesticides (OPPs) in olive and avocado oil samples, using atmospheric pressure microwave-assisted liquid-liquid extraction (APMAE) and solid-phase extraction or low-temperature precipitation as clean-up step. A simple glass system equipped with an air-cooled condenser was designed as an extraction vessel. The pesticides were partitioned between acetonitrile and oil solution in hexane. Analytical determinations were carried out by gas chromatography-flame photometric detection and gas chromatography-tandem mass spectrometry, using a triple quadrupole mass analyzer, for confirmation purposes. Several factors influencing the extraction efficiency were investigated and optimized through fractional factorial design and Doehlert design. Under optimal conditions the recovery of pesticides from oil at 0.025 microg g(-1) ranged from 71% to 103%, except for fenthion in avocado oil, with RSDs avocado oils produced in Chile. Detectable residues of different OPPs were observed in 85% of samples.

  7. Colloidal analysis of the asphaltene and their fractions with p-nitrophenol (PNP) of the Furrial crude oil for effect of the hydrotreating to different pressures

    Energy Technology Data Exchange (ETDEWEB)

    Labrador-Sanchez, H. [Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Grupo de Petroleo, Hidrocarburo y Derivados; Lindarte, L. [Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Grupo de Petroleo, Hidrocarburo y Derivados; Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Laboratorio de Catalisis y Metales de Transicion; Luis, M.A. [Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Laboratorio de Catalisis y Metales de Transicion

    2008-07-01

    A study was conducted to investigate the effect of hydrotreating Furrial crude oil on asphaltene and its fractions (A1 and A2) obtained by the p-Nitrophenol (PNP) method. A batch reactor was used at different pressures of hydrogen to perform 8 hydrotreating reactions on the Furrial crude oil. Asphaltenes were separated from the oil and fractioned with PNP to obtain A1 and A2. The asphaltene and their fractions were characterized for flocculation threshold, percentage of total sulfur, nuclear magnetic resonance of 13C and elemental composition. The study showed that hydrotreating influenced the colloidal behaviour of the asphaltene and that the catalyst promoted the conversion of asphaltene, its stability, and its desulfurization. Hydrotreating had a greater affect on the A2 fraction than the A1 fraction. 2 refs.

  8. Influence of smoking and obesity on alveolar-arterial gas pressure differences and dead space ventilation at rest and peak exercise in healthy men and women.

    Science.gov (United States)

    Gläser, Sven; Ittermann, Till; Koch, Beate; Schäper, Christoph; Felix, Stephan B; Völzke, Henry; Könemann, Raik; Ewert, Ralf; Hansen, James E

    2013-06-01

    Besides exercise intolerance, the assessment of ventilatory and perfusion adequacy allows additional insights in the disease pathophysiology in many cardiovascular or pulmonary diseases. Valid measurements of dead space/tidal volume ratios (VD/VT), arterial (a') - end-tidal (et) carbon dioxide (CO2) and oxygen (O2) pressure differences (p(a'-et)CO2) and (p(et-a')O2), and alveolar (A)-a' O2 pressure differences (p(A-a')O2) require using blood samples in addition to gas exchange analyses on a breath-by-breath-basis. Smoking and nutritional status are also important factors in defining disorders. Using a large healthy population we considered the impact of these factors to develop useful prediction equations. Incremental cycle exercise protocols were applied to apparently healthy volunteer adults who did not have structural heart disease or echocardiographic or lung function pathologies. Age, height, weight, and smoking were analysed for their influence on the target parameters in each gender. Reference values were determined by regression analyses. The final study sample consisted of 476 volunteers (190 female), aged 25-85 years. Smoking significantly influences p(A-a')O2 and p(a'-et)CO2 at rest and peak exercise, and VD/VT during exercise. Obesity influences upper limits of VD/VT, p(a'-et)CO2 and p(et-a')O2 at rest as well as p(A-a')O2 and p(et-a')O2 at exercise. Reference equations for never-smokers as well as for apparently healthy smokers considering influencing factors are given. Gender, age, height, weight, and smoking significantly influence gas exchange. Considering all of these factors this study provides a comprehensive set of reference equations derived from a large number of participants of a population-based study. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. What is different for people with MS who have pressure ulcers: A reflective study of the impact upon people's quality of life?

    Science.gov (United States)

    McGinnis, Elizabeth; Andrea Nelson, E; Gorecki, Claudia; Nixon, Jane

    2015-08-01

    Multiple Sclerosis (MS) is a progressive, degenerative disease of the central nervous system. People with advanced disease who have compromised mobility, activity, sensory and/or cognitive abilities are at risk of pressure ulcers. Having a pressure ulcer has a substantial impact on a person's quality of life; a generic pressure ulcer Health Related Quality of Life (HRQL) framework has been used in this study. To explore the views and opinions of patients with MS who have a pressure ulcer using a thematic framework and compare these to the general pressure ulcer population. Data for six MS patients was obtained through secondary analysis of transcripts from semi-structured interviews conducted during two studies which were part of a programme of HRQL Research. Patients with MS reported that their pressure ulcer affected their lives physically, psychologically and socially. All were confined to bed (as part of their pressure ulcer treatment) and therefore unable to participate in activities. Difficulties with movement and activity were partially attributed to the MS. Patients with MS did not report feeling ill with their pressure ulcer and expressed positive emotions and optimism. Pain or discomfort was a feature of the pressure ulcer for most patients. Pressure ulcers have a major impact on QOL for all patients. Problems with mobility and activity associated with the pressure ulcer were confounded by the MS. Copyright © 2015 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  10. Effects of sevoflurane on blood pressure in patients with different ages%七氟醚对不同年龄段患者血压的影响

    Institute of Scientific and Technical Information of China (English)

    徐珊; 袁志会; 郑雪; 周军; 朱昭琼

    2015-01-01

    Objective To investigate the effect of sevoflurane on blood pressure in patients with different ages and the optimal concen-tration of sevoflurane. Methods 60 patients underwent selective LC operation with conventional induction and sevoflurane maintenance were divided into three groups:the youth group (34 patients), the middle age group (20 patients) and the older age group (6 patients). The SBP, DBP, MAP, CETsev, number of patients, age of patients before induction and 10 min(T1), 20 min(T2), 30 min (T3), 60 min (T4) after induction were recorded. Results Fluctuate of blood pressure were in the normal range after anesthesia maintenance, and MAP were fluctuated within the range of ± 20% before induction. The age under different CETsev were of no significant difference in each time point (P>0. 05). The age composition ratio in different CETsev were of no significant difference in each time point (P>0. 05). As the time of anesthesia extended, the number of patients under 0% ~1%CETsev decreased from 35 to 11; the number of patients under 1% ~2%CETsev increased from 10 to 20;and the number of patients under 2% ~3%CETsev maintened in 14 approximately. Conclusion The effect of sevoflurane on blood pressure of different ages is approximate. 2% ~3% CETsev is the most optimal concentration during the main-tenance of anesthesia.%目的:探讨七氟醚麻醉维持中不同年龄段患者血压的改变及最适浓度。方法按常规手术安排顺序收入择期行腹腔镜胆囊切除术( LC)患者60例,常规诱导,全程吸入七氟醚维持麻醉,按年龄分为青年组34例,中年组20例,老年组6例。记录诱导前及麻醉维持后10 min(T1)、20 min(T2)、30 min(T3)、60 min(T4)的SBP、DBP、MAP、呼气末七氟醚浓度(CETsev)及各浓度下患者例数、年龄。结果麻醉维持后血压波动在正常范围,维持后MAP在诱导前MAP ±20%范围内波动。各时间点不同CETsev下患者年龄比较差异无统计学意义(P>0.05)。各时间

  11. FCT (functional computed tomography) evaluation of the lung volumes at different PEEP (positive-end expiratory pressure) ventilation pattern, in mechanical ventilated patients

    Energy Technology Data Exchange (ETDEWEB)

    Papi, M.G.; Di Segni, R.; Mazzetti, G.; Staffa, F. [Dept. of Radiology, S. Giovanni HS, Rome (Italy); Conforto, F.; Calimici, R.; Salvi, A. [Dept. of Anesthesiology, S. Giovanni HS, Rome (Italy); Matteucci, G. [Dept. of Pneumology, S. Giovanni HS, Rome (Italy)

    2007-06-15

    Purpose To evaluate with FCT (functional computed tomography) total lung volume and fractional lung volumes at different PEEP (positive end expiratory pressure) values in acute mechanically ventilated patients. Methods Nine ICU (intensive care unity) patients (1 lung pneumonia, 2 polytrauma, 2 sepsis, 3 brain surgery, 1 pulmonary embolism); mean age 48 {+-} 15 years, 6 male, 3 female; GE 16 MDCT scan was performed with acquisition from apex to diaphragma in seven seca at different PEEP values. Raw CT data were analysed by an advantage workstation to obtain volume density masks and histograms of both lungs and each lung and these density ranges were applied: - 1000 - 950 = hyper-ventilated lung, -900 - 650 well aerated lung, -950 - 500 all aerated lung, -500 + 200 lung tissue. Total and fractional lung volumes, Hounsfield unit (HU) were calculated and compared at different PEEP values (0, 5, 10, 15 cm H{sub 2}O). In four patients lung volumes were compared between the more and the less involved lung at increased PEEP. Statistic analysis: comparison means-medians tests. Results Data calculated at five PEEP showed unexpected decrease of total lung volume and increase of lung density (HU); proportionally no significant improvement of oxigenation. (orig.)

  12. Chemical Investigation of Saponins in Different Parts of Panax notoginseng by Pressurized Liquid Extraction and Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Si-Jia Hong

    2012-05-01

    Full Text Available A pressurized liquid extraction (PLE and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS method was developed for the qualitative determination of saponins in different parts of P. notoginseng, including rhizome, root, fibre root, seed, stem, leaf and flower. The samples were extracted using PLE. The analysis was achieved on a Zorbax SB-C18 column with gradient elution of acetonitrile and 8 mM aqueous ammonium acetate as mobile phase. The mass spectrometer was operated in the negative ion mode using the electrospray ionization, and a collision induced dissociation (CID experiment was also carried out to aid the identification of compounds. Forty one saponins were identified in different parts of P. notoginseng according to the fragmentation patterns and literature reports, among them, 21 saponins were confirmed by comparing the retention time and ESI-MS data with those of standard compounds. The results showed that the chemical characteristics were obviously diverse in different parts of P. notoginseng, which is helpful for pharmacological evaluation and quality control of P. notoginseng.

  13. Measurement of Electron Density Using the Multipole Resonance Probe, Langmuir Probe and Optical Emission Spectroscopy in Low Pressure Plasmas with Different Electron Energy Distribution Functions

    Science.gov (United States)

    Oberberg, Moritz; Bibinov, Nikita; Ries, Stefan; Awakowicz, Peter; Institute of Electrical Engineering; Plasma Technology Team

    2016-09-01

    In recently publication, the young diagnostic tool Multipole Resonance Probe (MRP) for electron density measurements was introduced. It is based on active plasma resonance spectroscopy (APRS). The probe was simulated und evaluated for different devices. The geometrical and electrical symmetry simplifies the APRS model, so that the electron density can be easily calculated from the measured resonance. In this work, low pressure nitrogen mixture plasmas with different electron energy distribution functions (EEDF) are investigated. The results of the MRP measurement are compared with measurements of a Langmuir Probe (LP) and Optical Emission Spectroscopy (OES). Probes and OES measure in different regimes of kinetic electron energy. Both probes measure electrons with low kinetic energy (<10 eV), whereas the OES is influenced by electrons with high kinetic energy which are needed for transitions of molecule bands. By the determination of the absolute intensity of N2(C-B) and N2+(B-X)electron temperature and density can be calculated. In a non-maxwellian plasma, all plasma diagnostics need to be combined.

  14. Cerebrospinal Fluid Amyloid-β 42, Total Tau and Phosphorylated Tau are Low in Patients with Normal Pressure Hydrocephalus: Analogies and Differences with Alzheimer's Disease.

    Science.gov (United States)

    Santangelo, Roberto; Cecchetti, Giordano; Bernasconi, Maria Paola; Cardamone, Rosalinda; Barbieri, Alessandra; Pinto, Patrizia; Passerini, Gabriella; Scomazzoni, Francesco; Comi, Giancarlo; Magnani, Giuseppe

    2017-01-01

    Co-existence of Alzheimer's disease (AD) in normal pressure hydrocephalus (NPH) is a frequent finding, thus a common pathophysiological basis between AD and NPH has been postulated. We measured CSF amyloid-β 42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) concentrations in a sample of 294 patients with different types of dementia and 32 subjects without dementia. We then compared scores on neuropsychological tests of NPH patients with pathological and normal CSF Aβ42 values. Aβ42 levels were significantly lower in NPH than in control patients, with no significant differences between AD and NPH. On the contrary, t-tau and p-tau levels were significantly lower in NPH than in AD, with no differences between NPH and controls. NPH patients with pathological Aβ42 levels did not perform worse than NPH patients with normal Aβ42 levels in any cognitive domains. Our data seem to support the hypothesis of amyloid accumulation in brains of NPH patients. Nevertheless, amyloid does not seem to play a pathogenetic role in the development of cognitive deficits in NPH.

  15. 不同钠水摄入对大鼠血压的影响%Effects of different intakes of sodium chloride and water on rat blood pressure

    Institute of Scientific and Technical Information of China (English)

    于国东; 全洪兵; 周路; 胡建锋; 梁劲生

    2011-01-01

    Backgrounds Long-term high intake of sodium chloride would result in high blood pressure, however the mechanism is uncertain. It is not conclusive whether there exists a retention of sodium and water, and it is still unclear regarding the interactions between sympathetic-adrenal system (SAS) and renin-angiotensin system (RAS).Objective To analyze the effects of different sodium chloride amounts of intake and water on the blood pressure of Wistar rats. Methods Twenty Wistar rats were randomly divided into 4 groups according to daily different intakes of sodium chloride and water with 5 rats in each group: low intake of sodium chloride with unlimited water supply,low intake of sodium chloride with physiologically-indispensable water (40 mL/d), high intake of sodium chloride with unlimited water supply, and high intake of sodium chloride with physiologically-indispensable water (40 mL/d).The intakes of water were measured daily, and urine samples were collected in the metabolic cages in each group.The difference values ( D-value) were calculated between the intake of water and the volume of urine daily.Weight and rat tail systolic arterial pressures were measured weekly for a total of 8 weeks. Blood noradrenalin (NE) and angiotensin Ⅱ (Ang Ⅱ ) were measured using enzyme-linked immunosorbent assays (ELISAs) 8 weeks later. Results The blood pressures in high sodium chloride intake groups with a slow increase of body weight were significantly higher than those of low intake of sodium chloride(P<0. 01 ) ;the D-value between the intake of water and the volume of urine, and Ang Ⅱ were significantly lower while blood NEs were higher. Furthermore, there exist significant differences in the blood pressures [(166.7±2.2)and (156.2±2.3)mm Hg], NEs [(3.5±0. 6) and (2.2 ± 0. 5 )μg/L] and Ang Ⅱ [(203. 5 ± 98.0 ) and(233.4 ± 101.7) ng/L] between high intake of sodium chloride group with physiologically-indispensable water and high intake of sodium chloride group with

  16. 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.

  17. 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.

  18. Subgroups based on thermal and pressure pain thresholds in women with chronic whiplash display differences in clinical presentation – an explorative study

    Directory of Open Access Journals (Sweden)

    Börsbo B

    2012-11-01

    Full Text Available Björn Börsbo,1,2 Gunilla M Liedberg,3 Mia Wallin,1,3 Björn Gerdle1,41Department of Medicine and Health Sciences, University of Linköping, Linköping, Sweden; 2Clinical Department of Rehabilitation Medicine, County Hospital Ryhov, Jönköping, Sweden; 3Department of Social and Welfare Studies, University of Linköping, Norrköping, Sweden; 4Pain and Rehabilitation Centre, UHL, Östergötland County Council, Linköping, SwedenPurpose: To investigate the presence of subgroups in chronic whiplash-associated disorders (WAD based on pain thresholds for pressure (PPT, cold (CPT, and heat (HPT and to compare these subgroups with respect to symptomatology, disability, and health aspects. Methods: Two groups of female subjects – patients with chronic WAD (n = 28 and healthy controls (CON; n = 29 – were investigated. Quantitative sensory testing (QST for thermal thresholds and algometry for PPT at four sites in the body (over the trapezius and tibialis anterior bilaterally were determined. Habitual pain intensities, psychological strain, disability, and health aspects were registered using a questionnaire.Results: A cluster analysis based on PPT, CPT, and HPT identified two subgroups of chronic WAD: one sensitive subgroup (s-WAD; n = 21, and one less sensitive subgroup (ls-WAD; n = 6. S-WAD displayed widespread hyperalgesia, whereas ls-WAD had localized hyperalgesia in the neck area, with tendencies to supernormal values in remote areas of the body. Generally, s-WAD had a significantly worse situation than the CON with respect to symptomatology, disability, and health aspects. The ls-WAD group was intermediary between s-WAD and CON in these aspects.Conclusion: Different explanations, eg, severity of the pain condition per se, etiological factors, and pre-trauma differences in pain sensitivity, may exist for the differences in pain thresholds between the two subgroups. Future research should investigate the role of pain thresholds in the chronic

  19. An investigation into the potential hypoalgesic effects of different amplitudes of PA mobilisations on the lumbar spine as measured by pressure pain thresholds (PPT).

    Science.gov (United States)

    Krouwel, Oliver; Hebron, Clair; Willett, Elaine

    2010-02-01

    Mobilisation of the spine is a common technique used in clinical practice. Studies have shown that mobilisation to the spine can decrease pain. The optimum treatment dose for achieving this has not so far been investigated. Previous studies that demonstrate the pain relieving effects of mobilisations have used large amplitude of oscillations. The importance of amplitude on pain relief has not been established. The current study aims to: a) Investigate the importance of amplitude as part of the treatment dose. b) To explore the extent of any pain reliving effects seen following mobilisations. The study employed a randomised, single blind, within-subjects repeated measure design. Thirty asymptomatic subjects participated. The subjects completed three experimental conditions on three separate occasions. The conditions were: large amplitude of oscillations (forces between 50 and 200N), small amplitude of oscillations (150N-200N) and quasi-static (maintained at 200N). Each condition involved a 3x1minute central PA mobilisation at a frequency of 1.5Hz on the lumbar spine. Pressure pain thresholds (PPT) were measured immediately before and after each intervention at 4 different sites. The sites were chosen to determine the extent of the hypoalgesic response. Results demonstrated a significant increase in PPT following lumbar mobilisations (p=0.013) at all measured sites. However, no significant difference was found between amplitude conditions (p=0.864). This study suggests that in asymptomatic subjects a systemic hypoalgesic response is caused by lumbar mobilisation regardless of amplitude.

  20. Impact of mitral E/A ratio on the accuracy of different echocardiographic indices to estimate left ventricular end-diastolic pressure.

    Science.gov (United States)

    Poerner, Tudor C; Goebel, Björn; Kralev, Stefan; Kaden, Jens J; Süselbeck, Tim; Haase, Karl K; Borggrefe, Martin; Haghi, Dariusch

    2007-05-01

    The objective was to determine the influence of left ventricular (LV) inflow pattern on the accuracy of different echocardiographic indices for estimation of LV end-diastolic pressure (LVEDP). Echocardiography with color tissue Doppler imaging (TDI) and LVEDP measurements using fluid-filled catheters were performed in 176 consecutive patients on the same day. Mitral peak diastolic velocities (E, A) and the difference in duration between pulmonary venous retrograde velocity and mitral A-velocity (PV(R)-A) were recorded by pulsed Doppler. Propagation velocity of the early mitral inflow (V(P)) was assessed using color M-mode. Early diastolic longitudinal (E'(lat)) and radial (E'(radial)) velocities of mitral annulus were measured by TDI. Area under ROC curve (AUC) for prediction of elevated LVEDP (> or =15 mm Hg) was computed for each parameter. For E/A > or =1 (98 patients, 46 with elevated LVEDP), the AUC values were: PV(R)-A: 0.914; E/E'(lat): 0.780; E/E'(radial): 0.729; E/V(P): 0.712 (p PV(R)-A reached statistical significance (AUC = 0.893, p PV(R)-A enabled the most accurate noninvasive estimation of LVEDP irrespective of LV filling profile and combined indices E/V(P), E/E'(lat) and E/E'(radial) represent more feasible alternatives for patients with mitral E/A-1.

  1. 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 ...

  2. Direct sun and airborne MAX-DOAS measurements of the collision induced oxygen complex, O2O2 absorption with significant pressure and temperature differences

    Directory of Open Access Journals (Sweden)

    E. Spinei

    2014-09-01

    Full Text Available The collision induced O2 complex, O2O2, is a very important trace gas in remote sensing measurements of aerosol and cloud properties. Some ground based MAX-DOAS measurements of O2O2 slant column density require correction factors of 0.75 ± 0.1 to reproduce radiative transfer modeling (RTM results for a near pure Rayleigh atmosphere. One of the potential causes of this discrepancy is believed to be uncertainty in laboratory measured O2O2 absorption cross section temperature and pressure dependence, due to difficulties in replicating atmospheric conditions in the laboratory environment. This paper presents direct-sun (DS and airborne multi-axis (AMAX DOAS measurements of O2O2 absorption optical depths under actual Earth atmospheric conditions in two wavelength regions (335–390 nm and 435–490 nm. DS irradiance measurements were made by the research grade MFDOAS instrument from 2007–2014 at seven sites with significant pressure (778–1013 hPa and O2O2 profile weighted temperature (247–275 K differences. Aircraft MAX-DOAS measurements were conducted by the University of Colorado AMAX-DOAS instrument on 29 January 2012 over the Southern Hemisphere subtropical Pacific Ocean. Scattered solar radiance spectra were collected at altitudes between 9 and 13.2 km, with O2O2 profile weighted temperatures of 231–244 K, and near pure Rayleigh scattering conditions. Due to the well defined DS air mass factors and extensively characterized atmospheric conditions during the AMAX-DOAS measurements, O2O2"pseudo" absorption cross sections, σ, are derived from the observed optical depths and estimated O2O2column densities. Vertical O2O2 columns are calculated from the atmospheric sounding temperature, pressure and specific humidity profiles. Based on the atmospheric DS observations, there is no pressure dependence of the O2O2 σ, within the measurement errors (3%. The two data sets are combined to derive peak σ temperature dependence of 360 and 477 nm

  3. 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

    . 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...

  4. Human cells derived from degenerate intervertebral discs respond differently to those derived from non-degenerate intervertebral discs following application of dynamic hydrostatic pressure.

    Science.gov (United States)

    Le Maitre, Christine Lyn; Frain, Jennie; Fotheringham, Andrew P; Freemont, Anthony J; Hoyland, Judith Alison

    2008-01-01

    The intervertebral disc (IVD) is one of the body's most important load-bearing structures with the major mechanical force experienced in the nucleus pulposus (NP) being hydrostatic pressure (HP). Physiological levels of HP have an anabolic effect on IVD matrix metabolism in cells derived from non-degenerate animal and herniated IVD while excessive HP has a catabolic effect. However, no studies have investigated the response of non-degenerate and degenerate human disc cells derived from non-herniated discs to HP. Here we investigate the effect of physiological HP on such cells using a novel loading rig. Human IVD cells (both NP and AF) cultured in alginate were subjected to dynamic HP (0.8-1.7 MPa 0.5 Hz) for 2 h. Cell viability was assessed, RNA extracted and qRT-PCR for 18 s, c-fos, Sox-9, collagen type II, aggrecan and MMP-3 performed. Cell viability was unaffected by the loading regime. In non-degenerate NP cells, HP increased c-fos, aggrecan, Sox-9 and collagen type II (significantly so in the case of c-fos and aggrecan), but not MMP-3 gene expression. In contrast, application of HP to AF or degenerate NP cells had no effect on target gene expression. Our data shows that cells obtained from the healthy NP respond to dynamic HP by up-regulating genes indicative of healthy matrix homeostasis. However, responses differed in degenerate NP cells suggesting that an altered mechanotransduction pathway may be operational.

  5. Identification of the pylorus from the intraluminal pH profile. Validation of the method by comparing it with transpyloric potential difference and pressure profile

    DEFF Research Database (Denmark)

    Rosenkilde-Gram, B; Højgaard, L; Kraglund, K;

    1990-01-01

    In contrast to the steady low intragastric pH, the pH in the proximal duodenum shows wide, rapid, and frequent fluctuations. This change in pH pattern may be used to localize the pylorus and thereby ensure reproducible measurements of duodenal pH at a known and reproducible distance from...... the pylorus. To validate this method of localizing the pylorus, simultaneous measurements were performed of the transpyloric pH and potential difference (PD) profile and of the pH and pressure profile in 10 normal subjects. pH-metry and PD-metry localized the pylorus within the same 1.5 cm in 82% of 104 5-min...... periods, and pH-metry and manometry localized the pylorus within the same 5 cm in 72% of 77 10-min periods. This agreement and accuracy seem satisfactory for most studies of intraluminal pH in the duodenum and make reliable long-term ambulatory recording of duodenal pH possible without serial...

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Pressure ulcers

    National Research Council Canada - National Science Library

    Reddy, Madhuri

    2011-01-01

    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...

  12. 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 ...

  13. Observation of different ceramide species from crude cellular extracts by normal-phase high-performance liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry

    NARCIS (Netherlands)

    Pettus, BJ; Bielawska, A; Kroesen, BJ; Moeller, PDR; Szulc, ZM; Hannun, YA; Busman, M

    2003-01-01

    Normal-phase high-performance liquid chromatography (NP-HPLC) coupled to atmospheric pressure chemical ionization mass spectrometry (APCI-MS) allows qualitative analysis of endogenous ceramide and dihydroceramide species from crude lipid extracts utilizing chromatographic methods readily adaptable

  14. Pressure ulcers

    OpenAIRE

    Monfre, Jill M.

    2011-01-01

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers, which affect 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.

  15. Different components of blood pressure are associated with increased risk of atherosclerotic cardiovascular disease versus heart failure in advanced chronic kidney disease.

    Science.gov (United States)

    Bansal, Nisha; McCulloch, Charles E; Lin, Feng; Robinson-Cohen, Cassianne; Rahman, Mahboob; Kusek, John W; Anderson, Amanda H; Xie, Dawei; Townsend, Raymond R; Lora, Claudia M; Wright, Jackson; Go, Alan S; Ojo, Akinlolu; Alper, Arnold; Lustigova, Eva; Cuevas, Magda; Kallem, Radhakrishna; Hsu, Chi-Yuan

    2016-12-01

    Blood pressure is a modifiable risk for cardiovascular disease (CVD). Among hemodialysis patients, there is a U-shaped association between blood pressure and risk of death. However, few studies have examined the association between blood pressure and CVD in patients with stage 4 and 5 chronic kidney disease. Here we studied 1795 Chronic Renal Insufficiency Cohort (CRIC) Study participants with estimated glomerular filtration rate 90 mm Hg versus 68 mm Hg versus 68 mm Hg versus <51 mmHg, but not for SBP or DBP. Thus, among participants with stage 4 and 5 chronic kidney disease, there was an independent association between higher SBP, DBP, and pulse pressure with the risk of atherosclerotic CVD, whereas only higher pulse pressure was independently associated with a greater risk of heart failure. Further trials are needed to determine whether aggressive reduction of blood pressure decreases the risk of CVD events in patients with stage 4 and 5 chronic kidney disease. Copyright © 2016 International Society of Nephrology. All rights reserved.

  16. Derived thermodynamic properties of [o-xylene or p-xylene + (acetic acid or tetrahydro-furan] at different temperatures and pressures

    Directory of Open Access Journals (Sweden)

    M. Rezaei-Sameti

    2011-08-01

    Full Text Available Thermal expansion coefficients , their excess values , isothermal coefficient of pressure excess molar enthalpy , partial molar volumes and excess partial molar volumes , were calculated from experimental densities. The isothermal coefficients of pressure excess molar enthalpy for binary mixtures {o-xylene or p-xylene + acetic acid} at temperatures 313.15-473.15 K and pressure 0.2-2 MPa are negative and for binary mixtures {o-xylene or p-xylene + tetrahydrofuran (THF} at temperatures 278. 15 K to 318.15 K and pressure 81.5 kPa are negative and with increasing temperature become more negative. The excess thermal expansions coefficient , for binary mixtures {o-xylene or p-xylene + acetic acid} at temperatures 313.15-473.15 K and pressure 0.2 MPa and 2 MPa are positive. The excess thermal expansions coefficient for binary mixtures {o-xylene or p-xylene + tetrahydrofuran (THF} at temperatures 278.15-318.15 K and pressure 81.5 kPa are positive and with increasing temperature become more positive. The excess molar volumes were correlated with a Redlich–Kister type equation.

  17. Properties of heavily impurity-doped PbSnTe liquid-phase epitaxial layers grown by the temperature difference method under controlled Te vapor pressure

    Science.gov (United States)

    Yasuda, Arata; Takahashi, Yatsuhiro; Suto, Ken; Nishizawa, Jun-ichi

    2017-07-01

    We propose the use of heavily impurity-doped Pb1-xSnxTe/PbTe epitaxial layers grown via the temperature difference method under controlled vapor pressure (TDM-CVP) liquid-phase epitaxy (LPE) for the preparation of IV-VI compounds for mid- to far-infrared optical device applications. A flat surface morphology and the distribution of a constant Sn concentration for 0.05 ≤ x ≤ 0.33 were observed in the epitaxial layers using electron-probe microanalysis. The segregation coefficient of Sn in Pb1-xSnxTe grown via TDM-CVP LPE (Tg = 640 °C) was xSSn?xLSn = 0.28. The appearance of the Fermi level pinning and persistent photoconductivity effects in In-doped PbSnTe were also proposed; we estimated that the activation energies of these processes were 2.8 and 39.7 meV, respectively, based on the In-doped Pb1-xSnxTe carrier profile as a function of ambient temperature. In Hall mobility measurements, Sn was assumed to be a main scattering center in the Pb1-xSnxTe epitaxial crystals. The impurity effect was also observed in Pb1-xSnxTe epitaxial growth, similar to the effects observed for Tl-doped PbTe bulk crystals. We concluded that the heavily doped Pb1-xSnxTe crystals grown via TDM-CVP LPE can be used to fabricate high-performance mid- to far-infrared optical devices.

  18. Noninvasive beat-to-beat finger arterial pressure monitoring during orthostasis: a comprehensive review of normal and abnormal responses at different ages.

    Science.gov (United States)

    van Wijnen, V K; Finucane, C; Harms, M P M; Nolan, H; Freeman, R L; Westerhof, B E; Kenny, R A; Ter Maaten, J C; Wieling, W

    2017-05-31

    Over the past 30 years, noninvasive beat-to-beat blood pressure (BP) monitoring has provided great insight into cardiovascular autonomic regulation during standing. Although traditional sphygmomanometric measurement of BP may be sufficient for detection of sustained orthostatic hypotension, it fails to capture the complexity of the underlying dynamic BP and heart rate responses. With the emerging use of noninvasive beat-to-beat BP monitoring for the assessment of orthostatic BP control in clinical and population studies, various definitions for abnormal orthostatic BP patterns have been used. Here, age-related changes in cardiovascular control in healthy subjects will be reviewed to define the spectrum of the most important abnormal orthostatic BP patterns within the first 180 s of standing. Abnormal orthostatic BP responses can be defined as initial orthostatic hypotension (a transient systolic BP fall of >40 mmHg within 15 s of standing), delayed BP recovery (an inability of systolic BP to recover to a value of >20 mmHg below baseline at 30 s after standing) and sustained orthostatic hypotension (a sustained decline in systolic BP of ≥20 mmHg occurring 60-180 s after standing). In the evaluation of patients with light-headedness, pre(syncope), (unexplained) falls or suspected autonomic dysfunction, it is essential to distinguish between normal cardiovascular autonomic regulation and these abnormal orthostatic BP responses. The prevalence, clinical relevance and underlying pathophysiological mechanisms of these patterns differ significantly across the lifespan. Initial orthostatic hypotension is important for identifying causes of syncope in younger adults, whereas delayed BP recovery and sustained orthostatic hypotension are essential for evaluating the risk of falls in older adults. © 2017 The Authors Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication of The Journal of Internal Medicine.

  19. 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

  20. Greater transforming growth factor-β in adult female SHR is dependent on blood pressure, but does not account for sex differences in renal T regulatory cells.

    Science.gov (United States)

    Tipton, Ashlee J; Musall, Jacqueline B; Crislip, G Ryan; Sullivan, Jennifer C

    2017-07-05

    Female spontaneously hypertensive rats (SHR) have more renal regulatory T cells (Tregs) than males, and greater levels of Tregs in female SHR is dependent on blood pressure (BP). However, the molecular mechanism responsible for greater Tregs in female SHR is unknown. Transforming growth factor (TGF)-β is a pleiotropic cytokine critical in the differentiation of naïve T cells into Tregs, and female SHR have higher TGF-β excretion than male SHR. The goals of the current study were to test the hypotheses that 1) female SHR have greater renal TGF-β expression than male SHR which is dependent on BP and 2) neutralizing TGF-β will decrease renal Tregs in female SHR. Renal cortices were isolated from 5 and 13 week old male and female SHR and TGF-β levels were measured via Western blot and ELISA. Adult female SHR have more free, active TGF-β1 than 5 week old female SHR (46% more) or male SHR (44% more than 5 week old males and 56% more than 13 week old male SHR). We confirmed greater TGF-β1 in adult female SHR was due to increases in BP and not sexual maturation by measuring TGF-β1 levels following treatment with BP lowering drugs or ovariectomy. Separate female SHR were treated with an antibody to TGF-β1,2,3; BP was measured and T cells were assessed in whole blood and the kidney. Neutralizing TGF-β had no effect on BP, although circulating Tregs decreased by 32% while Th17 cells increased by 64%. Renal Tregs were not altered by antibody treatment, although Th17 cells were decreased by 61%. In conclusion, although TGF-β promotes circulating Tregs in female SHR, it does not account for the sex difference in renal Tregs in SHR. Copyright © 2017, American Journal of Physiology-Renal Physiology.

  1. Counteracting negative venous line pressures to avoid arterial air bubbles: an experimental study comparing two different types of miniaturized extracorporeal perfusion systems.

    Science.gov (United States)

    Aboud, Anas; Mederos-Dahms, Hendrikje; Liebing, Kai; Zittermann, Armin; Schubert, Harald; Murray, Edward; Renner, Andre; Gummert, Jan; Börgermann, Jochen

    2015-05-29

    Because of its low rate of clinical complications, miniaturized extracorporeal perfusion systems (MEPS) are frequently used in heart centers worldwide. However, many recent studies refer to the higher probability of gaseous microemboli formation by MEPS, caused by subzero pressure values. This is the main reason why various de-airing devices were developed for today's perfusion systems. In the present study, we investigated the potential benefits of a simple one-way-valve connected to a volume replacement reservoir (OVR) for volume and pressure compensation. In an experimental study on 26 pigs, we compared MEPS (n = 13) with MEPS plus OVR (n = 13). Except OVR, perfusion equipment was identical in both groups. Primary endpoints were pressure values in the venous line and the right atrium as well as the number and volume of air bubbles. Secondary endpoints were biochemical parameters of systemic inflammatory response, ischemia, hemodilution and hemolysis. One animal was lost in the MEPS + OVR group. In the MEPS + OVR group no pressure values below -150 mmHg in the venous line and no values under -100 mmHg in right atrium were noticed. On the contrary, nearly 20% of venous pressure values in the MEPS group were below -150 and approximately 10% of right atrial pressure values were below -100 mmHg. Compared with the MEPS group, the bubble counter device showed lower numbers of arterial air bubbles in the MEPS + OVR group (mean ± SD: 13444 ± 5709 vs. 1 ± 2, respectively; p system with a volume replacement reservoir is able to counteract excessive negative venous line pressures and to reduce the number and volume of arterial air bubbles. This approach may lead to a lower rate of neurological complications.

  2. Intimal and medial contributions to the hydraulic resistance of the arterial wall at different pressures: a combined computational and experimental study.

    Science.gov (United States)

    Chooi, K Y; Comerford, A; Sherwin, S J; Weinberg, P D

    2016-06-01

    The hydraulic resistances of the intima and media determine water flux and the advection of macromolecules into and across the arterial wall. Despite several experimental and computational studies, these transport processes and their dependence on transmural pressure remain incompletely understood. Here, we use a combination of experimental and computational methods to ascertain how the hydraulic permeability of the rat abdominal aorta depends on these two layers and how it is affected by structural rearrangement of the media under pressure. Ex vivo experiments determined the conductance of the whole wall, the thickness of the media and the geometry of medial smooth muscle cells (SMCs) and extracellular matrix (ECM). Numerical methods were used to compute water flux through the media. Intimal values were obtained by subtraction. A mechanism was identified that modulates pressure-induced changes in medial transport properties: compaction of the ECM leading to spatial reorganization of SMCs. This is summarized in an empirical constitutive law for permeability and volumetric strain. It led to the physiologically interesting observation that, as a consequence of the changes in medial microstructure, the relative contributions of the intima and media to the hydraulic resistance of the wall depend on the applied pressure; medial resistance dominated at pressures above approximately 93 mmHg in this vessel.

  3. 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

  4. Relationship between zero-pressure-difference point and transporting power in distributed pump heating systems%分布式水泵供热系统零压差点与输送功率的关系

    Institute of Scientific and Technical Information of China (English)

    王芃; 邹平华; 雷翠红

    2011-01-01

    为了研究分布式水泵供热系统的水力工况和运行能耗,提出以零压差点作为该系统的水力标志,利用它与热源之间供、回水管段的总阻力损失分析管网中多个零压差点的分布,同时唯一确定了系统循环水泵的配置和压力分布.利用特定工况下的流量-压头图分析了各种循环水泵配置方案的输送功率,说明了零压差点与热媒输送功率的关系,并指出了系统达到需用功率的条件.通过工程实例的分析,定性讨论了若干典型的循环水泵配置方案.%Puts forward the zero-pressure-difference point to analyse the hydraulic condition and operating energy consumption of the distributed pump heating system. Studies the distribution of zero-pressure-difference points by total resistance loss of water supply and return pipes between heat source and one of zero-pressure-difference points,and determines the configuration of circulating pumps and pressure profile. The transporting power of heat medium is shown on flow-pressure head graph under certain condition,as well as the relationship between the power and zero-pressure-difference points. Puts forward the condition to achieve the required power. With a project case,discusses qualitatively several representative configuration schemes of circulating pumps.

  5. Effects of different pressure equalization methods on PSA and VSA processes for O2 production from air%不同均压方式对PSA和VSA空分制氧过程的影响

    Institute of Scientific and Technical Information of China (English)

    杨彦钢; 丁艳宾; 马正飞; 赵春风

    2012-01-01

    对存在于变压吸附(PSA)和真空变压吸附(VSA)空分制氧过程中的均压步骤进行研究,应用ASPEN-ADSIM软件,模拟并比较4种不同均压方式(塔顶向塔顶均压(T-T),塔底向塔底均压(B-B),塔顶和塔底双向均压(TB),塔顶向塔底均压(T-B))对过程的影响,分析均压步骤的物流浓度、流量以及均压结束时床层轴向浓度分布.结果表明:采用T-B均压方式的PSA和VSA过程得到的产品O2纯度和收率最高.在均压步骤,均降床层塔顶出气有利于死空间中O2的回收,且减少床层吸附相中N2的脱附带出,从而得到较高的产品O2收率;均升床层塔底进气可使床层N2的质量摩尔浓度前沿陡峭,塔顶洁净,因此得到较高的产品O2纯度.%The pressure equalization step in O2 production from air of pressure swing adsorption(PSA) and vacuum swing adsorption( VSA) processes was studied. Influences of four different pressure equalization modes (the two beds connected by top to top (T-T) ,bottom to bottom(B-B) ,top and bottom both sides(TB) ,top to bottom (T-B)) on O2 production from air were simulated by ASPEN-ADSIM. Accordingly , the O2 concentration and flowrate of the stream in the pressure equalization step and the bed concentration profiles at the end of pressure equalization step were investigated. Results showed that PSA and VSA processes adopting, the pressure equalization mode of T-B had the highest O2 purity and O2 recovery. During pressure equalization step, opening the outlet end of bed 1 ( experiencing the step of de-pressurizing pressure equalization) to discharge gas benefit the increasing of O2 recovery of product, but opening the inlet end of bed 2 (experiencing the step of pressurizing pressure equalization) to let gas in from bed 1 had the benefit to increasing O2 purity of product.

  6. Room temperature deposition of Al-doped ZnO thin films on glass by RF magnetron sputtering under different Ar gas pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Deok Kyu, E-mail: maruchi111@naver.com [Brain Korea 21 Chungbuk Information Technology Center, Chungbuk National University, Cheongju 361-763, Chungbuk (Korea, Republic of); Kim, Hong Bae [Division of Electronics and Information Engineering, Cheongju University, Cheongju 360-764, Chungbuk (Korea, Republic of)

    2011-01-12

    Research highlights: > The level of oxygen vacancies significantly decreases with increasing Ar gas pressure. > The number of oxygen vacancies decreases, and the number of oxygen atom in the lattice increases. > The lattice scattering increases and the mobility is reduced by the increased lattice scattering. > Finally, the reduced mobility increases the resistivity of the AZO thin films. > The mobility plays a major role in the conduction behavior of AZO thin films deposited at room temperature. - Abstract: Al-doped ZnO (AZO) thin films were deposited on glass substrates at room temperature by RF magnetron sputtering. The effects of Ar gas pressure on the structural, optical, and electrical properties were investigated. As the Ar gas pressure increased, the resistivities of the AZO thin films increased, the mobilities decreased, and the carrier concentrations were constant. X-ray photoelectron spectroscopy (XPS) showed that higher Ar gas pressures promoted O-Zn bond formation and reduced the number of oxygen vacancies. The reduction in mobility, which increased the resistivity, was attributed to increased lattice scattering by the oxygen atoms. In AZO thin films deposited at room temperature, the conduction characteristics are primarily influenced by the mobility.

  7. 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

  8. Saddle pressure measuring: Validity, reliability and power to discriminate between different saddle-fits (Zadeldrukmetingen bij het Paard: Validiteit, Herhaalbaarheid en de Mogelijkheid Verschillende Zadelpasvormen te Onderscheiden)

    NARCIS (Netherlands)

    Cocq, de P.; Weeren, van P.R.; Back, W.

    2006-01-01

    Saddle-fit is recognised as an important factor in the pathogenesis of back problems in horses and is empirically being evaluated by pressure measurements in clinical practice, although not much is known about the validity, reliability and usability of these devices in the equine field. This study w

  9. The value of the different indexes of electrocardiogram in diagnosing high blood pressure with left ventricular hypertrophy%心电图不同指标对高血压病左室肥厚的诊断价值

    Institute of Scientific and Technical Information of China (English)

    严国平; 颜玉芳

    2009-01-01

    目的 探讨心电图(ECG)各指标对诊断高血压病左室肥厚(LVH)的价值.方法 根据超声心动图(UCG)报告,确定观察组(A组)高血压病伴LVH 55例及对照组(B组)高血压病不伴LVH 50例;测定ECG各指标数据并计算其敏感性.结果 ECG不同指标对诊断高血压病LVH的价值存在较大差异,其中QRS波群电压指标敏感性最高,肢体导联室壁激动时间(VAT)次之,余指标敏感性较低.结论 ECG不同指标在诊断高血压病LVH时的价值不同.%Objective To investigate the value of the different indexes of electrocardiogram (ECG) in diagnosing high blood pressure with left ventricular hypertrophy. Methods 55 cases of high blood pressure with left ventricular hy-pertrophy and 50 cases of high blood pressure without left ventricular hypertrophy by the investigation of ultrasonic cardio-gram(UCG) were studied. The figure and sensitivity of the different indexes of ECG were determined. Results There was obvious difference among each ECG index in the diagnosing value of high blood pressure with left ventricular hypertro-phy, QRS wave amplitude had the most sensitive value compared with others. Conclusion It was different for each ECG index in the value of diagnosing high blood pressure with left ventricular hypertrophy. In order to improve the diagnosing ac-curacy, it is important to understand the different diagnosing value of each ECG index.

  10. Peer Pressure

    Science.gov (United States)

    ... who are unsure of themselves, new to the group, or inexperienced with peer pressure may also be more likely to give in. ... stand that makes you look uncool to your group. But these situations can be ... up to peer pressure, but it does take courage — yours: Listen to ...

  11. Experimental Research on Performance of Self-excited Inspiratory Pulsed Jet Device under Different Ambient Pressures%不同围压下自激吸气式脉冲射流装置性能试验研究

    Institute of Scientific and Technical Information of China (English)

    高传昌; 黄晓亮; 赵礼; 杜俐

    2011-01-01

    To address the technical problems of mud processing of deep water reservoirs and meet the urgent needs, experiments were conducted to assess the performance of a self-excited inspiratory pulsed jet device under different ambient pressures with testing device developed by ourselves, I n which the influence of the driving pressure, ambient pressure and standoff distance on the impact force of pulsed jet were analyzed. Preliminary research on the change of inspiratory quantity and start-up inspiratory pressure was also carried out. As the experimental results demonstrate, the pulsed jet impact force increases with the increase of driving pressure, but decreases with the increase of ambient pressure and standoff distance; the inspiratory capacity increases as driving pressure increases,at a speed varying according to the stimulus of ambient pressure ,and becomes stable gradually; start-up inspiratory pressure increases as ambient pressure increases,exhibiting certain regularity. The experiment provides basis for the in-depth study on self-excited inspiratory pulsed jet and its application in projects like reservoir desilting.%针对深水水库泥沙处理技术问题和需求的迫切性,运用自行研制的试验装置对不同围压(模拟不同水深)下的自激吸气式脉冲射流装置性能进行了试验,研究分析了工作压力、围压、靶距对脉冲射流冲击力的影响,并对装置吸气量的变化及启动吸气压力进行了初步分析.结果表明,脉冲射流冲击力随工作压力的增加而增大,随围压和靶距的增加而减小;装置吸气量随工作压力的增加而增大,增大的速度随围压的不同而不同,并逐渐趋于稳定;启动吸气压力随围压增加而增大,且表现出一定规律性.研究结果为进一步深入研究自激吸气式脉冲射流及其在水库清淤等工程应用方面提供依据.

  12. Surveying of Pressure in Posterior Chamber and Pressure Difference Between Anterior and Posterior Chambers of Rabbit Eye in Vivo%正常兔眼后房压强及前后房压强差值的在体监测

    Institute of Scientific and Technical Information of China (English)

    宋红芳; 杨红玉; 刘志成

    2011-01-01

    目的 寻求一种眼后房穿刺方法,并在体测量兔眼的前、后房压强差.方法 利用高精度压力传感器与空气差压传感器,采用"从角巩膜缘外周1~1.5mm处进针穿透巩膜,使针水平滑行于虹膜下而进入后房"的扎针方法,实现在体连续监测正常兔眼麻醉状态下的后房压强与前后房压强差值.结果 麻醉状态下兔眼后房压强的范围在839.93~2662.48Pa;前、后房压强差范围是46.15~85.52Pa,均值为59.73Pa,变化周期为11.17min.结论 扎针方法测量兔眼后房压强及前后房压强差值对眼球损伤较小,监测到的正常兔眼后房压强及前后房压强差值均在合理可信的范围内.监测方法的可行性为青光眼前后房压强差值的在体监测提供了新的思路.%Objective To find a proper method of puncturing into the posterior chamber of the rabbit eye and to measure the pressure in posterior chamber and the pressure difference between anterior and posterior chambers in vivo. Methods With the help of the high-accuracy pressure and pressure difference sensors, the pressure in posterior chamber and the pressure difference between anterior and posterior chambers were measured continuously in normal rabbit eyes with anesthesia in vivo. The needle directly punctured into the posterior chamber at 1 to 1.5 millimeters away from the cornea-sclera limbus, penetrated the sclera, and then slided horizontally the needle underneath the iris. Results The pressure value in posterior chamber was from 839. 93 Pa to 2662. 48 Pa, while the pressure difference between anterior and posterior chambers was from 46. 15 Pa to 85. 52 Pa with its average value 59. 73 Pa and the wave period was about 11. 17 min. Conclusions The puncture method for surveying the pressure of rabbit ' s chambers does less hurt to the eye-ball and the experimental data of the pressures in posterior chamber and pressure difference between anterior and posterior chambers. are authentic and

  13. Extended x-ray absorption fine structure measurements on radio frequency magnetron sputtered HfO2 thin films deposited with different oxygen partial pressures.

    Science.gov (United States)

    Maidul Haque, S; Nayak, C; Bhattacharyya, Dibyendu; Jha, S N; Sahoo, N K

    2016-03-20

    Two sets of HfO2 thin film have been deposited by the radio frequency magnetron sputtering technique at various oxygen partial pressures, one set without any substrate bias and another set with a 50 W pulsed dc substrate bias. The films have been characterized by extended x-ray absorption fine structure (EXAFS) measurements at the Hf L3 edge, and the structural information obtained from analysis of the EXAFS data has been used to explain the macroscopic behavior of the refractive index obtained from spectroscopic ellipsometry measurements. It has been observed that the variation of refractive index with oxygen partial pressure depends on the Hf-Hf bond length for the set of films deposited without substrate bias, while for the other set of films deposited with pulsed dc substrate bias, it depends on the oxygen coordination of the nearest neighbor shell surrounding Hf sites.

  14. Analysis of the body pressure/weight ratio distribution of the pressure sores suscep-tible parts at different lying position%不同卧位时压疮易患部位的人体压力/重力比值分布分析

    Institute of Scientific and Technical Information of China (English)

    唐玉超; 翁晨曦; 杨霞; 曹伟; 孙艳; 姜丽萍

    2015-01-01

    目的 通过测量三种不同卧位时压疮好发部位的压力/重力比值分布状况,探讨人体压力分布与局部组织受压的特征,为压疮防治提供依据. 方法 200名健康志愿者分别采取平卧位、侧卧位或半坐卧位,运用自制简易测压装置测量局部体表压力,计算压力/重力比值,运用SPSS 17. 0对其差异进行统计分析. 结果 局部压力与人体重力比值以及局部压力分布在性别方面差异具有统计学意义( P<0. 01 ). 不同卧位时体表相同受压部位的压力与人体重力比值差异具有统计学意义( P<0. 01 ). 男性骶尾部平卧位与半坐卧位压力与其重力比值分别为56. 46%,56. 81%;女性骶尾部平卧位与半坐卧位压力与人其重力比值分别为64. 38%,67. 00%.结论 人体体重与局部压力/重力比值分布有一定差异,不同卧位时,身体压力/重力比值分布女性均高于男性,尤其以骶尾部相差最大,足跟部相差最小;身体不同部位以骶尾部所占压力比值最大.%Objective To explore the characteristic of the pressure distribution and the local tissue compres-sion of human body by measuring the pressure/weight ratio distribution of the prone pressure sores parts for the three dif-ferent recumbent positions, thus to provide the foundation for prevention and cure of pressure sores. Methods The 200 healthy volunteers took the supine position, lateral poosition or semi-recumbent position respectively, the interface pressure was measured and recorded by simple pressure measuring device, the SPSS 17. 0 was used to do statistical a-nalysis. Results The partial pressure of the human body gravity ratio and the partial pressure in the same local pressed part in the aspect of gender among three positions had statistical significance ( P<0. 01 ) and the male sacral area pres-sure of their body gravity ratio in supine position and semi-recumbent position were 56. 46%, 56. 81% ; the female sa-cral area pressure of their

  15. Women with metabolic syndrome present different autonomic modulation and blood pressure response to an acute resistance exercise session compared with women without metabolic syndrome.

    Science.gov (United States)

    Tibana, Ramires A; Boullosa, Daniel A; Leicht, Anthony S; Prestes, Jonato

    2013-09-01

    Metabolic syndrome (MetS) is a cluster of risk factors in individuals with high risk of diabetes and heart disease. Resistance training (RT) has been proposed to be a safe, effective and worthwhile method for the prevention and treatment of metabolic and cardiovascular diseases. However, no study has analysed the acute response of blood pressure (BP) and autonomic control of heart rate (HR) after a RT session in female patients with MetS. The aim of the present study was to analyse the response of laboratory assessed and ambulatory BP and cardiac autonomic modulation after a RT session in women with MetS. Nine women without MetS (35.0 ± 6.7 years) and 10 women with MetS (34.1 ± 9.4 years) completed one experimental exercise session and a control session. Laboratory BP, heart rate variability (HRV) and ambulatory BP of each subject were measured at rest, over 60 min, and for 24 h after the end of the sessions, respectively. There was a significant reduction in systolic blood pressure (SBP), night time diastolic blood pressure (DBP) and mean blood pressure (MBP) only for women with MetS, for all periods after the RT session when compared with the control session (Pwomen with MetS (Pwomen with MetS that may offer a cardio-protective effect. Women with MetS exhibited an impaired autonomic modulation at rest and a lower acute autonomic responsiveness to a RT session. The dissociation between BP and HRV responses suggests that other factors than autonomic control could be involved in the hypotensive effect of a RT session in MetS patients.

  16. 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.

  17. Effects of Noninvasive Positive-Pressure Ventilation with Different Interfaces in Patients with Hypoxemia after Surgery for Stanford Type A Aortic Dissection

    OpenAIRE

    Yang, Yi; Sun, Lizhong; Liu, Nan; Hou, Xiaotong; Wang, Hong; Jia, Ming

    2015-01-01

    Background Hypoxemia is a severe perioperative complication that can substantially increase intensive care unit and hospital stay and mortality. The aim of this study was to determine the effects of non-invasive positive-pressure ventilation (NIPPV) in patients with hypoxemia after surgery for Stanford type A aortic dissection, and to compare the effects of helmet and mask NIPPV. Material/Methods We recruited 40 patients who developed hypoxemia within 24 h after extubation after surgery for S...

  18. 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

  19. A comparison of the heat transfer and pressure drop performance of R-134a-lubricant mixtures in different diameter smooth tubes and micro-fin tubes

    Energy Technology Data Exchange (ETDEWEB)

    Eckels, S.J. [Kansas State Univ., Manhattan, KS (United States). Dept. of Mechanical Engineering; Doerr, T.M.; Pate, M.B. [Iowa State Univ., Ames, IA (United States). Mechanical Engineering Dept.

    1998-10-01

    The average heat transfer coefficients and pressure drops during evaporation and condensation are reported for mixtures of R-134a and an ester lubricant in tubes of 12.7 mm (1/2 in.) outer diameter. The objective of this paper is to evaluate the performance of the R-134a-lubricant mixtures in these tubes and determine the performance benefits of the micro-fin tube. The performance benefits of the tubes with 12.7 mm (1/2 in.) outer diameter are compared to those of smaller tubes with 9.52 mm (3/8 in.) outer diameter. The lubricant used was a 169 SUS penta erythritol ester mixed-acid lubricant. The lubricant concentration was varied from 0--5.1% in the mixture. The average heat transfer coefficients in the 12.7 mm (1/2 in.) micro-fin tube were 50--150% higher than those for the 12.7 mm (1/2 in.) smooth tube, while pressure drops in the micro-fin tube were 5% to 50% higher than in the smooth tube. The addition of lubricant degraded the average heat transfer coefficients in all cases except during evaporation at low lubricant concentrations. Pressure drops were always increased with the addition of lubricant. The experimental results also indicate that tube diameter has some effect on the performance benefits of the micro-fin tube over that of the smooth tube.

  20. 定制鞋垫腰窝宽度对足底压力的影响%Effects of Custom-made Insoles with Different Inner Flank Widths on Plantar Pressure

    Institute of Scientific and Technical Information of China (English)

    李鑫; 徐波; 郭芷若; 沈妮

    2013-01-01

    Foot-insole interface pressure measurement was conducted to collect series of data such as peak-pressure, max-force, pressure-time integral generated by wearing custom-made insoles in different inner flank widths. Visual Analogue Scale(VAS) was applied to assess the impact of insole structure to plantar pressure comfort. The result shows that subjective comfort is rising in general along with inceasing of inner flank widths and significantly associated with pressure-time integral.%采用足一鞋垫界面压力测量法,测试了穿着不同鞋垫里腰窝宽度结构的鞋时足底的峰值压强、最大受力面积、压强一时间积分等数据,并结合视觉模拟主观舒适度评分法,分析了鞋垫结构对足部压力舒适度的影响.结果表明,主观舒适度大体随着腰窝宽度的增加而增加,且与冲量(压力一时间积分)显著相关.

  1. Different TreatmentMethods and Effect of Pressure Ulcers Correlation Studies%压疮不同治疗方法与治疗效果的相关性研究

    Institute of Scientific and Technical Information of China (English)

    王丽霞

    2015-01-01

    Objective: The decompression sores of different treatment methods and treatment effect, analysis the correlation of the two, provide the basis for continuous improve the effect of the treatment of pressure ulcers.Methods: 37 cases of I-III period in patients with pressure ulcers, divided into two groups using the random number table, singular for the team, water gel dressings in the treatment of pressure ulcers, dual to the control group, with more than hundred bond in the treatment of pressure ulcers, to collect data. Results: The team from one period to the average pressure ulcers heal days is far less than the control group.Conclusion: The cura-tive effect of different treatment of pressure ulcers, should use the most effective treatment method, in the shortest time, achieve the best treatment effect, to reduce the patients pain.%目的:了解压疮不同的治疗方法及治疗效果,分析二者的相关性,为不断提高压疮的治疗效果提供依据。方法采用37例Ⅰ-Ⅲ期压疮患者,利用随机数字表分为两组,单数为研究组,用水胶体敷料治疗压疮,双数为对照组,用百多邦治疗压疮,采集数据。结果研究组各期压疮平均治愈天数远远少于对照组。结论不同的治疗方法对压疮的治疗效果不同,应采用最有效的治疗方法,以最短的时间,达到最佳治疗效果,以减少患者痛苦。

  2. 14 CFR 29.1325 - Static pressure and pressure altimeter systems.

    Science.gov (United States)

    2010-01-01

    ...: Installation § 29.1325 Static pressure and pressure altimeter systems. (a) Each instrument with static air case... between air pressure in the static pressure system and true ambient atmospheric static pressure is not..., when on the alternate static pressure system, differs from the reading of altimeter when on the primary...

  3. [Pressure ulcer prevention with pressure-reducing seat cushions].

    Science.gov (United States)

    Reijnen, Guido; Heule, Freerk

    2012-01-01

    Analysis of the effectiveness of pressure-reducing seat cushions. Literature review. Investigation of the literature yielded 8 relevant studies. These studies encompassed three clinical trials with a total of 296 patients, and five laboratory experiments with a total of 107 subjects, including patients. The publications were written at level A (RCT and meta-analysis) and level B (other study forms) according to the principles of evidence-based medicine. Both the pressure parameters of the pressure-reducing seat cushion and the development of pressure ulcers were used as measures for outcome. A 7.6 cm foam cushion was used as reference; it was not considered as one of the pressure-reducing systems. Two studies compared different types of air seat cushions with a foam/gel seat cushion. The best distribution of pressure was found for the air compartment seat cushion. This type of seat cushion provided the smallest contact surface with high pressures. Three studies compared the pressure-reducing systems with a 7.6 cm foam cushion. The methodologically most solid one of these three studies found a lower incidence of sitting-related pressure ulcers for users of a pressure-reducing system (0.9 vs. 6.7%; p = 0.04). The two other studies had too low a power to show significant differences. These two compared different types of foam/gel seat cushions and a low profile air seat cushion and found no significant differences in distribution of pressures. One study compared various foam cushions of differing thickness and found that foam cushions most optimally distributed pressure at a thickness of 8 centimetres. Pressure-reducing systems are effective in preventing pressure ulcers. Within the group of pressure-reducing systems, the air compartment seat cushion has the best pressure-distributing properties.

  4. 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 ... Pressure Targets are Different for Very Old Adults High blood pressure (also called hypertension) increases your chance of having ...

  5. Tackifier Dispersions to Make Pressure Sensitive Adhesives

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-02-01

    Development of new processes for tackifier dispersion could improve the production of pressure sensitive adhesives. Pressure sensitive adhesives (PSAs) have the ability to adhere to different surfaces with manual or finger pressure.

  6. Pressure Sores

    Science.gov (United States)

    ... injury. Some chronic diseases, such as diabetes and hardening of the arteries, make it hard for pressure ... Use a mild soap and warm (not hot) water. Apply moisturizers so your skin doesn’t get ...

  7. Pressure sensor

    Science.gov (United States)

    Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.

    2015-09-29

    Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  8. High pressure effects on fruits and vegetables

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Matser, A.M.

    2016-01-01

    The chapter provides an overview on different high pressure based treatments (high pressure pasteurization, blanching, pressure-assisted thermal processing, pressure-shift freezing and thawing) available for the preservation of fruits and vegetable products and extending their shelf life. Pressure t

  9. High pressure effects on fruits and vegetables

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Matser, A.M.

    2016-01-01

    The chapter provides an overview on different high pressure based treatments (high pressure pasteurization, blanching, pressure-assisted thermal processing, pressure-shift freezing and thawing) available for the preservation of fruits and vegetable products and extending their shelf life. Pressure

  10. 缓冲气压对CO2激光Al靶等离子体参量的影响%Analysis of the properties of CO2 laser-induced aluminum plasma at different ambient pressures

    Institute of Scientific and Technical Information of China (English)

    吴涛; 王新兵; 唐建; 饶志明; 王少义

    2011-01-01

    为了研究缓冲气压对激光等离子体参量的影响,利用CO2激光烧蚀Al靶产生等离子体,缓冲气压变化范围为10-4pa ~2×103Pa,激光脉冲能量为180mJ/脉冲,在局域热平衡和光学薄等离子体假设下,采用发射光谱法计算了等离子体的电子温度和电子密度,并研究了缓冲气压对这些参量的影响.结果表明,等离子体的电子温度和电子密度分别在1.05eV ~2.47eV与1.95×1016cm-3~10.5×1016cm-3范围内,Al等离子体的电子温度随气压的增大而减少;低缓冲气压时,电子密度随气压增大而减小,当气压达到600Pa时,激光脉冲会击穿空气形成等离子体,电子密度又开始上升,当气压超过3000Pa时,空气等离子体会屏蔽激光脉冲能量,使到达靶面的激光能量急剧下降,Al原子的特征谱线也随之减弱而几乎消失.这一结果对理解缓冲气压对激光与物质相互作用过程的影响是有帮助的.%In order to study the properties of laser-induced plasma at different ambient pressures, emission spectroscopy was studied on aluminum plasma generated by C02 laser with energy of 180mJ/pulse at different air ambient pressures. The dependency of plasma temperature and density on ambient pressures were estimated from the analysis of spectral data by assuming the conditions of local thermodynamic equilibrium and optically thin plasma. Electron temperature was measured in the range of 1. 05eV ~2.47eV, and electron density was measured in the range of 1. 95 x 1016cm-3 ~ 10. 5 x 1016cm-3, as the ambient pressure was varied from 10-4Pa to 2 x 103Pa. The results show that the plasma temperature decreases with the ambient pressures. At first, the electron density decreases with the increase of ambient pressure under low pressure. When the pressure reaches 600Pa, the broken air plasma may interact with Al vapor and the electron density increases with the pressure increasing. For larger ambient pressure up to 3000Pa, the Al emission

  11. Effects of different levels of end-expiratory positive pressure on lung recruitment and protection in patients with acute respiratory distress syndrome

    Institute of Scientific and Technical Information of China (English)

    GUO Feng-mei; DING Jing-jing; SU Xin; XU Hui-ying; SHI Yi

    2008-01-01

    Background It is still controversial as to the implementation of higher positive end-expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS).This study was conducted to compare the lower and higher PEEP in patients with ARDS ventilated with low tidal volume,to investigate the relationship between the recruited lung volume by higher PEEP and relevant independent variables and to provide a bedside estimate of the percentage of potentially recruitable lung by higher PEEP.Methods Twenty-four patients with ARDS were studied.A lung recruiting maneuver was performed,then each patient was ventilated with PEEP of 8 cmH2O for 4 hours and subsequently with PEEP of 16 cmH2O for 4 hours.At the end of each PEEP level period,gas exchange,hemodynamic data,lung mechanics,stress index "b" of the dynamic pressure-time curve,intrinsic PEEP and recruited volume by PEEP were measured.Results Fourteen patients were recruiters whose alveolar recruited volumes induced by PEEP 16 cmH2O were (425±65) ml and 10 patients were non-recruiters.Compared with the PEEP 8 cmH2O period,after the application of the PEEP 16 cmH2O,the PaO2/FiO2 ratio and static lung compliance both remained unchanged in non-recruiters,whereas they increased significantly in recruiters.Changes in PaO2/FiO2 and static lung compliance after PEEP increase were independently associated with the alveolar recruitment.Analyzing the relationship between recruiting maneuver (RM)-induced change in end-expiratory lung volume and the alveolar recruitment induced by PEEP,we found a notable correlation.Conclusions The results of this study indicated that the potential for alveolar recruitment might vary among the ARDS population and the higher PEEP levels should be limited to recruiters.Improving in PaO2/FiO2,static lung compliance after PEEP increase and the shape of the pressure-time curve could be helpful for PEEP application.

  12. Effect of different drug administration time on blood pressure circadian rhythm and morning blood pressure of non dipper type dosing in elderly hypertensive%不同给药时间对非杓型老年高血压患者血压昼夜节律及清晨血压的影响

    Institute of Scientific and Technical Information of China (English)

    于淼; 李潞; 熊亦涵

    2013-01-01

    Objective To investigate effect of different drug administration time on blood pressure circadian rhythm and morning blood pressure of non dipper type dosing in elderly hypertensive. Methods 98 elderly non dipper hypertensive patients were selected , randomly divided into two groups, and were given amlodipine besylate 5mg for 12 weeks in the early morning and evening. Before and after treatment, two groups had monitored ambulatory blood pressure, recorded the mean blood pressure changes in day and night, calculated the percentage of circadian blood pressure difference, measured the early morning blood pressure with family self testing during, and calculated the morning blood pressure mean value and standard rate. Results After 12 weeks, the blood pressure circadian difference giving drug at night were higher than in the morning (P<0.05). No matter the family self testing early morning blood pressure in SBP or DBP, evening medication group were lower than control group in the morning, and the success rate was better (P<0.05). Conclusion Evening medication group adjusts better non dipper circadian rhythm of blood pressure in patients with essential hypertension in elderly patients and reduces the morning blood pressure.%目的:探讨不同给药时间对非杓型老年高血压患者血压昼夜节律及清晨血压的影响。方法入选非杓型老年高血压患者98例,随机分成两组,分别在清晨及晚上给予苯磺酸氨氯地平5 mg治疗12周,并于治疗前后进行24h动态血压监测,记录治疗前后两组白天、夜间平均血压变化,并计算出血压昼夜差值百分比,并于治疗期间通过家庭自测血压方法测量清晨血压,并计算出清晨血压平均值及达标率。结果12周后晚上服药组血压昼夜差值百分比高于清晨服药组(P<0.05),且家庭自测清晨血压无论是SBP还是DBP,晚上服药组均低于清晨服药组,且达标率较好(P<0.05)。结论晚上服药组能更好地调整非杓型老

  13. Liquid phase growth of GaSe1-xTex mixed crystals by temperature difference method under controlled vapor pressure

    Science.gov (United States)

    Zhao, S.; Sato, Y.; Maeda, K.; Tanabe, T.; Ohtani, H.; Oyama, Y.

    2017-06-01

    GaSe crystal is one of a group of nonlinear optical (NLO) crystals expected to be utilized as a highly efficient generators of terahertz waves. However, GaSe has some drawbacks that limit it from further application. Firstly, it has poor crystallinity and, secondly, the layers are prone to exfoliation. In this work, crystal growth was carried out at a constant low temperature under a controlled Se vapor pressure to improve the crystallinity. In addition, Te was added in order to grow mixed crystals to improve the bonding forces between the layers. X-ray fluorescence was used to measure the Te composition in the grown crystals. Red shifts of the excitation peaks were found from photoluminescence with increasing Te composition, indicating that mixed crystals were successfully grown. The lattice constant, c, was calculated from the results of X-ray diffraction and was shown to have an almost linear dependence on Te composition.

  14. "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.

  15. 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).

  16. Is single room hospital accommodation associated with differences in healthcare-associated infection, falls, pressure ulcers or medication errors? A natural experiment with non-equivalent controls

    Science.gov (United States)

    Maben, Jill; Murrells, Trevor; Griffiths, Peter

    2016-01-01

    Objectives A wide range of patient benefits have been attributed to single room hospital accommodation including a reduction in adverse patient safety events. However, studies have been limited to the US with limited evidence from elsewhere. The aim of this study was to assess the impact on safety outcomes of the move to a newly built all single room acute hospital. Methods A natural experiment investigating the move to 100% single room accommodation in acute assessment, surgical and older people’s wards. Move to 100% single room accommodation compared to ‘steady state’ and ‘new build’ control hospitals. Falls, pressure ulcer, medication error, meticillin-resistant Staphylococcus aureus and Clostridium difficile rates from routine data sources were measured over 36 months. Results Five of 15 time series in the wards that moved to single room accommodation revealed changes that coincided with the move to the new all single room hospital: specifically, increased fall, pressure ulcer and Clostridium difficile rates in the older people’s ward, and temporary increases in falls and medication errors in the acute assessment unit. However, because the case mix of the older people’s ward changed, and because the increase in falls and medication errors on the acute assessment ward did not last longer than six months, no clear effect of single rooms on the safety outcomes was demonstrated. There were no changes to safety events coinciding with the move at the new build control site. Conclusion For all changes in patient safety events that coincided with the move to single rooms, we found plausible alternative explanations such as case-mix change or disruption as a result of the re-organization of services after the move. The results provide no evidence of either benefit or harm from all single room accommodation in terms of safety-related outcomes, although there may be short-term risks associated with a move to single rooms. PMID:26811373

  17. 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

    Science.gov (United States)

    Ivanov, Sergey V.; Buzykin, Oleg G.

    2016-12-01

    A classical approach is applied to calculate pressure broadening coefficients of CO2 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 CO2-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 lmax = 24. New improved algorithm of classical rotational frequency selection is applied. The dependences of CO2 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).

  18. Pressure Drop in Cyclone Separator at High Pressure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air leakage from the stand pipe into the cyclone was specially focused. A semi-empirical model was developed for the predic tion of the pressure drop of the cyclone separator at different operate pressures with the effect of air leakage and inlet solid loading. The operate pressure, air leakage and inlet solid loading act as significant roles in cyclone pressure drop. The pressure drop increases with the increasing of pressure and decreases with the increasing of the flow rate of air leakage from the standpipe and with the increasing of the inlet solid loading.

  19. Two-Phase condensation Heat Transfer Coefficients Heat Transfer Coefficients and Pressure drops of R-404A for different Condensing Temperatures in a smooth and Micro-Fin Tube

    Directory of Open Access Journals (Sweden)

    DR. S.N. Sapali

    2009-11-01

    Full Text Available Two phase heat transfer coefficients and pressure drops of R-404A in a smooth (8.56 mm ID and micro-fin tube (8.96 mm ID are experimentally investigated. Different from previous studies, the present experiments are performed for different condensing temperatures, with superheating and sub cooling and using hermetically sealed compressor. The test runs are done at average saturated condensing temperatures ranging from 35oC to 60oC. The mass fluxes are between 90 and 800 kg m-2s-1 . The experimental results from both smooth and micro-fin tubes show that the average heat transfer coefficient and pressure drop increases with mass flux but decreases with increasing condensing temperature. The average heat transfer coefficient is 30-210% higher for micro-fin tube than that of smooth tube, with moderate increase in pressure drop ranging from 10-55%. New correlations based on the data gathered during the experimentation for predicting condensation heat transfer coefficients are proposed for wide range of practical applications.

  20. 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.

  1. 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.

  2. 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 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 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.

  3. 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.

    2017-07-01

    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.

  4. High pressure homogenization processing, thermal treatment and milk matrix affect in vitro bioaccessibility of phenolics in apple, grape and orange juice to different extents.

    Science.gov (United States)

    He, Zhiyong; Tao, Yadan; Zeng, Maomao; Zhang, Shuang; Tao, Guanjun; Qin, Fang; Chen, Jie

    2016-06-01

    The effects of high pressure homogenization processing (HPHP), thermal treatment (TT) and milk matrix (soy, skimmed and whole milk) on the phenolic bioaccessibility and the ABTS scavenging activity of apple, grape and orange juice (AJ, GJ and OJ) were investigated. HPHP and soy milk diminished AJ's total phenolic bioaccessibility 29.3%, 26.3%, respectively, whereas TT and bovine milk hardly affected it. HPHP had little effect on GJ's and OJ's total phenolic bioaccessibility, while TT enhanced them 27.3-33.9%, 19.0-29.2%, respectively, and milk matrix increased them 26.6-31.1%, 13.3-43.4%, respectively. Furthermore, TT (80 °C/30 min) and TT (90 °C/30 s) presented the similar influences on GJ's and OJ's phenolic bioaccessibility. Skimmed milk showed a better enhancing effect on OJ's total phenolic bioaccessibility than soy and whole milk, but had a similar effect on GJ's as whole milk. These results contribute to promoting the health benefits of fruit juices by optimizing the processing and formulas in the food industry.

  5. Structural inheritance and difference between Ti2AlC, Ti3AlC2 and Ti5Al2C3 under pressure from first principles

    Science.gov (United States)

    Gao, Qing-He; Du, An; Yang, Ze-Jin

    2017-01-01

    The structural inheritance and difference between Ti2AlC, Ti3AlC2 and Ti5Al2C3 under pressure from first principles are studied. The results indicate that the lattice parameter a are almost the same within Ti2AlC, Ti3AlC2 and Ti5Al2C3, and the value of c in Ti5Al2C3 is the sum of Ti2AlC and Ti3AlC2 which is revealed by the covalently bonded chain in the electron density difference: Al-Ti-C-Ti-Al for Ti2AlC, Al-Ti2-C-Ti1-C-Ti2-Al for Ti3AlC2 and Al-Ti3-C2-Ti3-Al-Ti2-C1-Ti1-C1-Ti2-Al for Ti5Al2C3. The calculated axial compressibilities, volumetric shrinkage, elastic constant c11, c33/c11 ratio, bulk modulus, shear modulus, and Young’s modulus of Ti5Al2C3 are within the range of the end members (Ti2AlC and Ti3AlC2) in a wide pressure range of 0-100 GPa. Only Ti2AlC is isotropic crystal at about 50 GPa within the Ti-Al-C compounds. All of the Ti 3d density of states curves of the three compounds move from lower energy to higher energy level with pressure increasing. The similarities of respective bond length, bond overlap population (Ti-C, Ti-Al and Ti-Ti), atom Mulliken charges under pressure as well as the electron density difference for the three compounds are discovered. Among the Ti-Al-C ternary compounds, Ti-Ti bond behaves least compressibility, whereas the Ti-Al bond is softer than that of Ti-C bonds, which can also been confirmed by the density of states and electron density difference. Bond overlap populations of Ti-Ti, Ti-C and Ti-Al indicate that the ionicity interaction becomes more and more stronger in the three structures as the pressure increasing. Mulliken charges of Ti1, Ti2, Ti3, C and Al are 0.65, 0.42, 0.39, ‑0.73, ‑0.04 at 0 GPa, respectively, which are consistent with the Pauling scale.

  6. Influence of hemodialysis with difference transfusion speed on blood pressure and heart rate of elderly patients%血液透析不同的回血速度对老年人血压及心率的影响

    Institute of Scientific and Technical Information of China (English)

    安惠旒

    2012-01-01

    [Objective]To study the influence of difference transfusion speed on blood pressure and heart rate of elderly patients with hemodialysis. [Methods]30 elderly patients in Xingtai Third Hospital were treated by hemodialysis with difference transfusion speed, the blood pressure and heart rate before and after transfusion were observed. [Results]The transfusion speed of 100 ml/min and 80 ml /min would increase the blood pressure and heart rate of patients, and 50 ml/min was safe, which had less effect on blood pressure and heart rate. [Conclusion]The proper transfusion speed can reduce the incidence rate of hypertensive complications in elderly patients with hemodialysis , and improve the quality of hemodialysis.%目的 探讨不同的回血速度对透析老年人血压及心率的影响.方法 采用不同回血速度对邢台市第三医院30例老年透析患者进行血液透析治疗,观察回血前后患者血压及心率的情况.结果 100 ml/min、80 ml/min回血速度会引起患者血压升高,心率加快;50 ml/min回血速度较安全,对血压及心率影响不大(P<0.05).结论 适当的回血速度可以减少老年透析患者高血压并发症的发生,可提高患者的透析质量.

  7. 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