Dynamic Pressure Changes Research Articles

Injectable LiNc-BuO loaded microspheres as in vivo EPR oxygen sensors after co-implantation with tumor cells

Electron paramagnetic resonance (EPR) oximetry is a technique which allows accurate and repeatable oxygen measurements. We encapsulated a highly oxygen sensitive particulate EPR spin probe into microparticles to improve its dispersibility and, hence, facilitate the administration. These biocompatible, non-toxic microspheres contained 5–10 % (w/w) spin probe and had an oxygen sensitivity of 0.60±0.01µT/mmHg. To evaluate the performance of the microparticles as oxygen sensors, they were co-implanted with syngeneic tumor cells in 2 different rat strains. Thus, tissue injury was avoided and the microparticles were distributed all over the tumor tissue. Dynamic changes of the intratumoral oxygen partial pressure during inhalation of 8 %, 21 %, or 100 % oxygen were monitored in vivo by EPR spectroscopy and quantified. Values were verified in vivo by invasive fluorometric measurements using Oxylite probes and ex vivo by pimonidazole adduct accumulation. There were no hints that the tumor physiology or tissue oxygenation had been altered by the microparticles. Hence, these microprobes offer great potential as oxygen sensors in preclinical research, not only for EPR spectroscopy but also for EPR imaging. For instance, the assessment of tissue oxygenation during therapeutic interventions might help understanding pathophysiological processes and lead to an individualized treatment planning or the use of formulations with hypoxia triggered release of active agents.

Magnetospheric ULF waves with increasing amplitude related to solar wind dynamic pressure changes: The Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations

AbstractUltralow frequency (ULF) waves play an important role in transferring energy by buffeting the magnetosphere with solar wind pressure impulses. The amplitudes of magnetospheric ULF waves, which are induced by solar wind dynamic pressure enhancements or shocks, are thought to damp in one half a wave cycle or an entire wave cycle. We report in situ observations of solar wind dynamic pressure impulse‐induced magnetospheric ULF waves with increasing amplitudes. We found six ULF wave events induced by solar wind dynamic pressure enhancements with slow but clear wave amplitude increase. During three or four wave cycles, the amplitudes of ion velocities and electric field of these waves increased continuously by 1.3–4.4 times. Two significant events were selected to further study the characteristics of these ULF waves. We found that the wave amplitude growth is mainly contributed by the toroidal mode wave. Three possible mechanisms of causing the wave amplitude increase are discussed. First, solar wind dynamic pressure perturbations, which are observed in a duration of 20–30 min, might transfer energy to the magnetospheric ULF waves continually. Second, the wave amplitude increase in the radial electric field may be caused by superposition of two wave modes, a standing wave excited by the solar wind dynamic impulse and a propagating compressional wave directly induced by solar wind oscillations. When superposed, the two wave modes fit observations as does a calculation that superposes electric fields from two wave sources. Third, the normal of the solar wind discontinuity is at an angle to the Sun‐Earth line. Thus, the discontinuity will affect the dayside magnetopause continuously for a long time.

Magnetospheric ULF waves with increasing amplitude related to solar wind dynamic pressure changes: The Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations

Magnetospheric ULF waves with increasing amplitude related to solar wind dynamic pressure changes: The Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations

A STATISTICAL SURVEY OF DYNAMIC PRESSURE PULSES IN THE SOLAR WIND BASED ONWINDOBSERVATIONS

Solar wind dynamic pressure pulse (DPP) structures, across which the dynamic pressure changes abruptly over timescales from a few seconds to several minutes, are often observed in the near-Earth space environment. The space weather effects of DPPs on the magnetosphere-ionosphere coupling system have been widely investigated in the last two decades. In this study, we perform a statistical survey on the properties of DPPs near 1 AU based on nearly 20 years of observations from the WIND spacecraft. It is found that only a tiny fraction of DPPs (around 4.2%) can be regarded as interplanetary shocks. For most DPPs, the total pressure (the sum of the thermal pressure and magnetic pressure) remains in equilibrium, but there also exists a small fraction of DPPs that are not pressure-balanced. The overwhelming majority of DPPs are associated with solar wind disturbances, including coronal mass ejection-related flows, corotating interaction regions, as well as complex ejecta. The annual variations of the averaged occurrence rate of DPPs are roughly in phase with the solar activity during solar cycle 23, and during the rising phase of solar cycle 24.

Steady-state tilt has no effect on cerebrovascular CO2 reactivity in anterior and posterior cerebral circulations.

What is the central question of this study? We investigated the effects of superimposed tilt and hypercapnia-induced cerebral arteriolar dilatation on anterior and posterior cerebrovascular CO2 reactivity using hyperoxic rebreathing in human participants. What is the main finding and its importance? The main findings are threefold: (i) cerebrovascular CO2 reactivity in the anterior and posterior cerebrovasculature is unchanged with tilt; (ii) cerebral autoregulation is unlikely responsible due to unchanging cerebrovascular resistance reactivity between positions; and (iii) cerebral blood flow is not pressure passive during tilt as it is with pharmacological or lower body negative pressure-induced changes in mean arterial pressure, suggesting that sympathetic activation or balanced transmural pressures during head-down tilt regulate cerebral blood flow. Cerebral autoregulation is a protective feature of the cerebrovasculature that maintains relatively constant cerebral perfusion in the face of static and dynamic fluctuations in mean arterial pressure (MAP). However, the extent that the cerebrovasculature can autoregulate in the face of superimposed steady-state orthostasis-induced changes in MAP (e.g. head-up and head-down tilt; HUT and HDT) and CO2 -mediated arteriolar dilatation is unknown. We tested the effects of steady-state tilt on cerebrovascular CO2 reactivity in the middle and and posterior cerebral artery in the following five body positions: 90 deg HUT, 45 deg HUT, supine, 45 deg HDT and 90 deg HDT on a tilt table during a modified hyperoxic rebreathing test. Absolute and relative cerebrovascular CO2 reactivity [cerebral blood velocity (CBV)/CO2 ], cerebrovascular resistance (CVR) reactivity (CVR/CO2 ) and MAP reactivity (MAP/CO2 ) were quantified using linear regression. Mean arterial pressure was significantly elevated in 90 deg HDT compared with other positions during baseline steady-state tilt (P < 0.01). Absolute CBV/CO2 and CVR/CO2 were greater in the middle cerebral artery than the posterior cerebral artery (P < 0.01) in all body positions, but relative measures were not different (P = 0.143 and P = 0.360, respectively), nor was there any interaction with tilt position. In addition, there was no difference in absolute (P = 0.556) and relative MAP/CO2 (P = 0.308) between positions. Our data demonstrate that cerebral blood flow remains well regulated during superimposed steady-state orthostatic stress and dynamic changes in the partial pressure of end-tidal CO2 during rebreathing. Cerebral autoregulation is likely not the mechanism responsible, but rather sympathetic nervous system activation or a balanced cerebrovascular transmural pressure with HDT maintains resting cerebral blood flow and cerebrovascular CO2 reactivity during rebreathing.

Properties of Solar Wind Dynamic Pressure Pulses at 1 AU during the Deep Minimum between Solar Cycles 23 and 24

Observations during the deep solar minimum between Solar Cycles 23 and 24 offer an opportunity for characterizing the nature of solar wind dynamic pressure pulses (DPPs) under extreme solar activity. In this study, we identify 226 DPPs from July 2008 to June 2009 using an automatic detection algorithm based on high-resolution plasma data from the Wind spacecraft to investigate the features of DPPs during the deep solar minimum. For comparison, the similarities and differences of the statistical characteristics of the DPPs during the deep solar minimum and during the previous solar minimum are also examined. It is found that the number and the occurrence rate of DPPs during the deep solar minimum are only about one-third of those during the previous minimum, which may be attributed to lower solar wind dynamic pressure and weaker dynamic pressure fluctuations. From a statistical perspective, however, no obvious difference is apparent between the other basic DPP properties in the two solar minima, such as the absolute and relative amplitude of the dynamic pressure changes and the durations of the transition regions of DPPs. Other basic properties of the DPPs during the deep solar minimum are as follows: 1) the distribution of the absolute value of the dynamic pressure amplitude change peaks at 1.0 – 1.5 nPa, 2) the most probable relative pressure changes are 0.2 – 0.8, 3) DPP durations are broad-peaked between 150 s and 210 s with a mean of about 171 s, 4) 76.7 % of the DPPs can be considered as pressure balance structures, 5) dynamic pressure changes across DPPs are dominated by density changes, 6) specially, during the deep solar minimum, a considerable portion of DPPs, 86.7 %, are associated with large-scale solar wind transients such as interplanetary coronal mass ejections (ICMEs) and stream interaction regions (SIRs).

Monitoring and modelling of gas dynamics in multi-level longwall top coal caving of ultra-thick coal seams, Part II: Numerical modelling

The longwall top coal caving method, which enables the most productive exploitation of thick/ultra-thick coal seams, may result in a distinct geomechanical response of strata and associated gas emission patterns around longwall layouts. A two-way sequential coupling of a geomechanical and a reservoir simulator for the modelling of gas emissions around a longwall top coal caving (LTCC) panels was developed building on the understanding established from the analysis of in-situ gas pressure and concentration measurements carried out at Coal Mine Velenje in Slovenia. Model findings have shown that the modelling method implemented can reproduce the dynamic changes of stresses and gas pressure around a LTCC face and predict the total gas emissions and mixed gas concentrations accurately. It was found that, in LTCC panels, although the rate of gas emission from mined coal depends highly on the coal face advance, floor coal and roof goaf act as a constant and steady gas source accounting for a considerable part of the overall gas emission. Research has shown that, at first and/or second mining levels of multi-level LTCC mining, a notable stress relief and pore pressure drop induced by fracturing of the mined and roof coal can be experienced within 40m ahead of the face-line. In the floor coal, on the other hand, the pore pressure change was found to extend to 20m below the mining horizon. Model results have clearly shown the permeability enhancement and gas mobilisation zones around the LTCC panel, which can be the target zones for gas drainage boreholes.

AUTOMATIC DETECTION ALGORITHM OF DYNAMIC PRESSURE PULSES IN THE SOLAR WIND

Dynamic pressure pulses (DPPs) in the solar wind are a significant phenomenon closely related to the solar-terrestrial connection and physical processes of solar wind dynamics. In order to automatically identify DPPs from solar wind measurements, we develop a procedure with a three-step detection algorithm that is able to rapidly select DPPs from the plasma data stream and simultaneously define the transition region where large dynamic pressure variations occur and demarcate the upstream and downstream region by selecting the relatively quiet status before and after the abrupt change in dynamic pressure. To demonstrate the usefulness, efficiency, and accuracy of this procedure, we have applied it to the Wind observations from 1996 to 2008 by successfully obtaining the DPPs. The procedure can also be applied to other solar wind spacecraft observation data sets with different time resolutions.

Embryonic stem cell-derived osteocytes are capable of responding to mechanical oscillatory hydrostatic pressure

Osteoblasts can be derived from embryonic stem cells (ESCs) by a 30 day differentiation process, whereupon cells spontaneously differentiate upon removal of LIF and respond to exogenously added 1,25α(OH)2 vitamin D3 with enhanced matrix mineralization. However, bone is a load-bearing tissue that has to perform under dynamic pressure changes during daily movement, a capacity that is executed by osteocytes. At present, it is unclear whether ESC-derived osteogenic cultures contain osteocytes and whether these are capable of responding to a relevant cyclic hydrostatic compression stimulus.Here, we show that ESC-osteoblastogenesis is followed by the generation of osteocytes and then mechanically load ESC-derived osteogenic cultures in a compression chamber using a cyclic loading protocol. Following mechanical loading of the cells, iNOS mRNA was upregulated 31-fold, which was consistent with a role for iNOS as an immediate early mechanoresponsive gene. Further analysis of matrix and bone-specific genes suggested a cellular response in favor of matrix remodeling. Immediate iNOS upregulation also correlated with a concomitant increase in Ctnnb1 and Tcf7l2 mRNAs along with increased nuclear TCF transcriptional activity, while the mRNA for the repressive Tcf7l1 was downregulated, providing a possible mechanistic explanation for the noted matrix remodeling. We conclude that ESC-derived osteocytes are capable of responding to relevant mechanical cues, at least such that mimic oscillatory compression stress, which not only provides new basic understanding, but also information that likely will be important for their use in cell-based regenerative therapies.

Design of a LabVIEW‐Based Virtual Instrument for Langendorff‐Prepared Isolated Heart Experiments

Isolated heart preparations have the advantage of being void of confounding humoral and neuronal input when studying its response to drugs or other interventions. Dynamic changes in left ventricular pressure (LVP) and its derivatives, coronary flow and perfusion pressure, electrocardiogram (ECG), and other variables can be assessed over time. However, a reliable data acquisition system (DAS) is critical to successfully conduct a meaningful experiment. Plug‐and‐play DAS often have the disadvantage of limited flexibility because of proprietary software, limited programmability and/or required specific signal conditioning systems. In contrast, LabVIEW allows maximal user flexibility, but requires a significant amount of programming before use. We report the design and operation of a LabVIEW‐based Virtual Instrument (VI) for Langendorff‐prepared isolated heart experiments. All analog inputs from various signal conditioners are fed into an analog‐digital converter controlled by the VI's DA assistant and sampled and displayed at 200 Hz. Threshold‐controlled HR is calculated from ECG; systolic, diastolic and mean pressures are calculated from LVP; for all less dynamic signals a running 3 sec average is calculated. Continuous or discontinuous data recording can be initiated manually or by an internal or external trigger. Data read‐out is continuously appended into an Excel‐compatible file. Thus, the described VI turns LabVIEW into an affordable alternative to more rigid and expensive DAS while providing maximal flexibility for future adjustments. Supported by VA (CARA‐026‐10F), NIH &amp; institutional funds.

The shape of the Venusian bow shock at solar minimum and maximum: Revisit based on VEX observations

Several factors control the bow shock position at Venus, including short-term period responses (solar wind dynamic pressure) and long-term period variations (solar activity). Based on Venus Express (VEX) observations, we revisit the influence of solar activity on the Venusian bow shock location, by accurately determining not only the shock terminator distance but also the subsolar point with a three-parameter fit (TPF) method. At the same time, VEX covers a larger range of solar zenith angles (SZA) at the Venusian bow shock (from about 10 to 135 degrees) than the Pioneer Venus Orbiter (PVO) spacecraft. Fitting results display that the Venusian bow shock is farther away from Venus at solar maximum than at solar minimum. The subsolar stand-off distance increases from 1.364 planetary radii at solar minimum to 1.459RV at solar maximum, while the terminator shock distance changes from 2.087RV to 2.146RV. Inspection of the bow shock and the induced magnetosphere boundary (IMB) locations clearly shows a positive correlation for every orbit, while the average bow shock location is not responsive to changes in the solar wind dynamic pressure.

Can we predict complications after elective carotid artery angioplasty and stenting with a simple Valsalva test?

Objectives. Arterial baroreflex plays a key role in short-term blood pressure balancing. It can also be quantified noninvasively with baroreceptor sensitivity during Valsalva manoeuver. The aim of the study was to evaluate the role of Valsalva manoeuver as a potential marker of possible autonomic dysfunction in patients after carotid artery angioplasty and stenting.Materials and methods. We evaluated dynamic changes of blood pressure during Valsalva manoeuver (Valsalva ratio, adrenergic baroreceptor sensitivity) in 22 patients (11 male; 63.2 ± 6.7 years) with symptomatic, unilateral internal carotid artery stenosis, and compared results with age and sex matched control subjects.Results. Valsalva ratio between baseline and post-procedural day (1.26 ± 0.13 vs 1.46 ± 0.31; p=0.002) was the only statistically significant parameter. All other tests (also between the study and the control group), cardiovagal and adrenergic, revealed no significant differences.Conclusion. We were not able to show that Valsalva manoeuver, as a simple, non-invasive and easy to perform test, could reliably confirm patients who are at a risk for postprocedural complications. It seems that most of the compensatory mechanisms, occurring after a revascularisation procedure, remain largely unclarified.

Resource-saving method of electric arc spraying

On the modern stage of development of resource-saving technologies the basic support is given to the economy of materials consumption without the change of the amount of their use. The special attention is given to the universal methods of renewal of details, and electric arc spraying which has a wide application did not become an exception. The review of the literary data shows that the applied electric arc spraying guns have a large expense of the compressed air. It results in the intensive affecting of the nebulizing stream on the liquid metal of the ends of molten electrodes and the degradation of the coverage quality. With the purpose of decrease in the compressed air consumption it is suggested to use a pulsating nebulizing stream. A corresponding device is worked out, to the stationary arc spraying gun EM-17, providing the pulsating mode of expiration of the nebulizing stream of air within the limits of 0–130 Herts. The oscillograms of change of dynamic pressure are given. It is set that a nebulizing stream has a pulsating form with the temporal intervals. The dependence of properties of the pulsating nebulizing stream on the frequency of closure of the channel of nozzle of the arc spray gun is shown. The obtained results of research show the reduction of the consumption of nebulizing stream at spraying. The optimal frequencies which provide the least consumption of the compressed air are 40–60 Herts, decrease at 42 %. The obtained data testifies the method of control of the nebulizing stream at spraying.

Modulation of the dayside diffuse auroral intensity by the solar wind dynamic pressure

AbstractCompared to the recently improved understanding of the nightside diffuse aurora, the mechanism(s) responsible for the dayside diffuse auroral precipitation remains limitedly understood. We investigate the dayside diffuse aurora observed by the all‐sky imagers of Chinese Arctic Yellow River Station in the time interval of 02:00–10:00 UT (05:00–13:00 magnetic local time) on 2 January 2006. In this interval, the intensity of dayside diffuse aurora is highly correlated with the solar wind dynamic pressure with a maximum coefficient of 0.89. Moreover, there are similar spectra characteristics in the Pc5 range between the intensity of dayside diffuse aurora and solar wind dynamic pressure (proton density) during a portion of the time interval, in which the interplanetary magnetic field Bz is northward. The observation indicates that changes in solar wind dynamic pressure can efficiently modulate the magnitude of the dayside diffuse aurora, except when the interplanetary magnetic field is southward. The enhancement of the solar wind dynamic pressure can provide favorable circumstances for dayside chorus wave generation, so we consider that the dayside chorus could be a candidate for the production of the dayside diffuse aurora. Furthermore, since the compressional Pc4‐Pc5 pulsations can also modulate the intensity of whistler mode chorus waves, the solar wind dynamic pressure modulates the dayside diffuse aurora through affecting dayside chorus wave activity and the associated scattering process.

Research on Correlation between the Pressure and the Grain Moisture Content in the Rectangular Silo

In the process of grain drying, the pressure of grain formation has a certain rule when the grains flow in the silo. In the project, we research on the method of the saturated pressure would measure grain moisture in the silo. The dynamic and static pressure is set up the simulation equation in the rectangular silo. We explore dynamic and static pressure change regularity and analysis the trend of the dynamic and static pressure with height in the rectangular silo.The results show that with the increase of filling height, dynamic and static pressure has gradually becoming saturated trend. At the same time, we study on the correlation between the saturated pressure and moisture content. When the grain reaches a certain height, the pressure achieves the ultimate value.

Sudden impulse observations in the dayside magnetosphere by THEMIS

AbstractWe present a study of the magnetospheric response to interplanetary shocks. We show eight events with simultaneous observations of sudden impulses in the dayside magnetosphere and interplanetary shocks in the solar wind. The spacecraft measurements in the equatorial plane, even those very close to the Earth, can be interpreted in terms of the vortices predicted by previous studies employing global MHD models. In fact, these vortices are velocity oscillations with the properties of Alfvén waves. The amplitude and frequency of the oscillations depend on radial distance from the Earth. The amplitude of the velocity perturbations decreases with increase of the density and magnetic field magnitude, but the velocity amplitude shows no dependence on magnitude of the solar wind dynamic pressure change attending the interplanetary shocks. The oscillations are observed both in the outer magnetosphere and the plasmasphere, but they become less sinusoidal near the plasmapause, i.e., in the region with a large‐density gradient. The amplitude of the magnetic field enhancement in the sudden impulses also depends on the radial distance. The MHD simulations successfully predict the amplitudes of magnetic field increase and the first cycles of the velocity oscillations in these events.

Intracellular Carbonic Anhydrase Activity Sensitizes Cancer Cell pH Signaling to Dynamic Changes in CO2 Partial Pressure

Carbonic anhydrase (CA) enzymes catalyze the chemical equilibration among CO2, HCO3(-) and H(+). Intracellular CA (CAi) isoforms are present in certain types of cancer, and growing evidence suggests that low levels correlate with disease severity. However, their physiological role remains unclear. Cancer cell CAi activity, measured as cytoplasmic CO2 hydration rate (kf), ranged from high in colorectal HCT116 (∼2 s(-1)), bladder RT112 and colorectal HT29, moderate in fibrosarcoma HT1080 to negligible (i.e. spontaneous kf = 0.18 s(-1)) in cervical HeLa and breast MDA-MB-468 cells. CAi activity in cells correlated with CAII immunoreactivity and enzymatic activity in membrane-free lysates, suggesting that soluble CAII is an important intracellular isoform. CAi catalysis was not obligatory for supporting acid extrusion by H(+) efflux or HCO3(-) influx, nor for maintaining intracellular pH (pHi) uniformity. However, in the absence of CAi activity, acid loading from a highly alkaline pHi was rate-limited by HCO3(-) supply from spontaneous CO2 hydration. In solid tumors, time-dependence of blood flow can result in fluctuations of CO2 partial pressure (pCO2) that disturb cytoplasmic CO2-HCO3(-)-H(+) equilibrium. In cancer cells with high CAi activity, extracellular pCO2 fluctuations evoked faster and larger pHi oscillations. Functionally, these resulted in larger pH-dependent intracellular [Ca(2+)] oscillations and stronger inhibition of the mTORC1 pathway reported by S6 kinase phosphorylation. In contrast, the pHi of cells with low CAi activity was less responsive to pCO2 fluctuations. Such low pass filtering would "buffer" cancer cell pHi from non-steady-state extracellular pCO2. Thus, CAi activity determines the coupling between pCO2 (a function of tumor perfusion) and pHi (a potent modulator of cancer cell physiology).

Relation between Dynamic Pressure and Displacement of Free Surface in Two-Layer Sloshing between a Magnetic Fluid and Silicone Oil

We performed experiments regarding two-layer sloshing, using a magnetic fluid and silicone oil, and measured the dynamic pressure change using pressure transducers. We also investigated displacements of the free surface by comparing it with the dynamic pressure, clarifying the relation between them, both in the presence and absence of a magnetic field.

Four-year dynamic observation and study on standardized management of elderly patients with type 2 diabetes in Beijing Yongding Road Community

Purpose This study aimed to understand the joint standard of blood glucose, blood lipids, and blood pressure in elderly patients >60 years of age with type 2 diabetes in the Beijing Yongding Road Community. Methods One hundred ninety-two elderly patients >60 years of age who were diagnosed with type 2 diabetes in Yongding Road Community served as the investigation subjects, underwent standard management, and the dynamic changes in blood glucose, blood lipids, and blood pressure were monitored for 48 months. Results At the end of the observation period, the standard rates of fasting blood glucose and postprandial blood glucose were 72.55% and 80.00%, respectively, which were increased compared with 55.73% and 56.08% at baseline (P 0.05). The standard rates of TG and LDL-C were 76.71% and 60.38%, respectively, which were increased compared with 54.69% and 34.74% at baseline, and the standard rate of HDL-C was 13.64%, which was decreased compared with 40.10% at baseline (P Conclusion Standardized management of elderly patients with diabetes in the Community can improve the joint standard rate of blood glucose, blood lipids, and blood pressure. The optimal control rate and joint standard rate are the important indices for evaluating the quality of diabetes management.

Assessment Of Blood Pressure For Determining The Time To Perform First Postural Change In Patients After Cardiac Surgery In The Intensive Care Unit

Objective: Changing the posture of patients is an integral part of nursing care. However, postural changes after cardiac surgery can have potential adverse effects on patients. To prevent these effects, an appropriate assessment of the patient’s condition is necessary. This study aimed to clarify the assessment by nurses to determine the timing to perform the first postural change in patients who have undergone cardiac surgery, with special reference to changes in blood pressure. Methods: A qualitative study using semistructured interviews was conducted among registered nurses working in an intensive care unit of a hospital. Results: Participants (n = 12) focused on four factors when interpreting a patient’s blood pressure: “rewarming,” “circulatory blood volume,” “cardiac output,” and “body movements.” Participants assessed their patients based on two criteria: the first emphasizing specific blood pressure values and the second focusing on stability of the blood pressure, representing static and dynamic parameters, respectively. Nurses made an appropriate assessment by careful consideration of these two criteria. Conclusion: The present results demonstrate that the assessment of blood pressure includes four factors. We propose that the assessment of dynamic changes in blood pressure are required in addition to the static status. This study may support nurse’s assessment for the first postural change in patients after cardiac surgery.