Morning surge in blood pressure is an independent cardiovascular risk factor in the middleaged and the elderly. Whether such a surge occurs in young subjects is not known. Eighty normotensive subjects (age: 21.8 ± 1.3 yr) measured their own blood pressure (BP) using an automatic device (Omron HEM-7080,) on going to bed and on waking up, for 2 consecutive days. In contrast to large morning BP surges reported for older age groups, there was much smaller but significant (P
Hypertension professionals from Asia have been meeting together for the last decade to discuss how to improve the management of hypertension. Based on these education and research activities, the Hypertension, brain, cardiovascular and renal Outcome Prevention and Evidence in Asia (HOPE Asia) Network was officially established in June 2018 and includes experts from 12 countries/regions across Asia. Among the numerous research and review papers published by members of the HOPE Asia Network since 2017, publications in three key areas provide important guidance on the management of hypertension in Asia. This article highlights key consensus documents, which relate to the Asian characteristics of hypertension, home blood pressure monitoring (HBPM), and ambulatory blood pressure monitoring (ABPM). Hypertension and hypertension-related diseases are common in Asia, and their characteristics differ from those in other populations. It is essential that these are taken into consideration to provide the best opportunity for achieving "perfect 24-hour blood pressure control", guided by out-of-office (home and ambulatory) blood pressure monitoring. These region-specific consensus documents should contribute to optimizing individual and population-based hypertension management strategies in Asian country. In addition, the HOPE Asia Network model provides a good example of the local interpretation, modification, and dissemination of international best practice to benefit specific populations.
Taylor's spatial frame (TSF) and Ilizarov external fixators (IEF) are two circular external fixator commonly used to address complex deformity and fractures. There is currently no data available comparing the biomechanical properties of these two external fixators. This study looks into the mechanical characteristics of each system. TSF rings with 6 oblique struts, 4 tube connectors, 4 threaded rods, and 6 threaded rods were compared to a standard IEF rings with 4 threaded rods. Compression and torsional loading was performed to the frame as well as construct with Polyvinylchloride tubes. TSF rings with 4 tube connectors had the highest stiffness (3288 N/mm) while TSF rings with 6 struts was the least stiff. The situation was reversed for torsion where TSF rings with 6 oblique struts had the highest torsional stiffness (82.01 Nm/Degree) and frame Ilizarov rings with 4 threaded rods the least. Standard TSF construct of two ring with 6 oblique struts have better torsional stiffness and lower axial stiffness compared to the standard IEF.
Hypertension is a potentially unsafe health ailment, which can be indicated directly from the blood pressure (BP). Hypertension always leads to other health complications. Continuous monitoring of BP is very important; however, cuff-based BP measurements are discrete and uncomfortable to the user. To address this need, a cuff-less, continuous, and noninvasive BP measurement system is proposed using the photoplethysmograph (PPG) signal and demographic features using machine learning (ML) algorithms. PPG signals were acquired from 219 subjects, which undergo preprocessing and feature extraction steps. Time, frequency, and time-frequency domain features were extracted from the PPG and their derivative signals. Feature selection techniques were used to reduce the computational complexity and to decrease the chance of over-fitting the ML algorithms. The features were then used to train and evaluate ML algorithms. The best regression models were selected for systolic BP (SBP) and diastolic BP (DBP) estimation individually. Gaussian process regression (GPR) along with the ReliefF feature selection algorithm outperforms other algorithms in estimating SBP and DBP with a root mean square error (RMSE) of 6.74 and 3.59, respectively. This ML model can be implemented in hardware systems to continuously monitor BP and avoid any critical health conditions due to sudden changes.
Full Heuslers alloys are a fascinating class of materials leading to many technological applications. These have been studied widely under ambient conditions. However, less attention been paid to study them under the effect of compression and strain. Here in this work Co2YZ (Y= Cr, Nb, Ta, V and Z = Al, Ga) Heusler alloys have been studied comprehensively under pressure variations. Calculated lattice constants are in reasonable agreement with the available data. It is determined that lattice constant deceases with the increase in tensile stress and increases by increasing pressure in reverse direction. Band profiles reveals the half metallic nature of the studied compounds. The bond length decreases while band gap increases in compressive strain. The compounds are found to be reflective in visible region, as characteristics of the metals. The magnetic moments reveal the half-mettalic ferromagnetic nature of the compounds.
An in-house quasi-dimensional code has been developed which simulate the overlap, intake, compression, combustion, as well as expansion and exhaust processes of a homogeneous charged internal combustion engine (ICE). A detailed chemical kinetic mechanism, constituting of 39 species and 148 elementary reactions, has been used in conjunction with above code to study the combustion of CNG under IC engine conditions. Two different criteria, based on pressure rise and mass of fuel burned, are used to detect the onset of ignition. Parametric studies are conducted to show the effect of compression ratio, initial pressure, intake temperature and equivalence ratio, on the time of ignition and fuel burning rate. The results obtained from the modelling show a good agreement with the experimental data.
This work focuses on the use of X-ray tomography in investigating the flow distribution in a structured packed bed. Cross sections of the liquid hold up distribution in a 10 cm diameter column packed with Katapak-SP12 are obtained at various column heights for different liquid flow rates. The repartition of the liquid hold up between baskets and corrugated sheets is quantified. Wall wipers and column wall effects are visualized. Results are obtained from an initially dry column without gas flow.
High strength concrete (HSC) has lower ductility, but higher in strength compared to normal strength concretes. The strength and ductility of HSC can be improved by applying external confinement, such as steel strapping tensioning technique (SSTT). However, SSTT was literately reported effective in confining circular specimens, but the effectiveness of SSTT on square cross section specimens are yet well investigated. This study focuses on HSC square cross section specimens with different corner ratio, which were right angle and rounded corner. In addition, the effect of different number of layer of steel straps confining around the specimens under optimum lateral pre-tensioning stress also been investigated. The number of layers was fixed to two layers and four layers. Fifteen HSC specimens with dimension of 88 mm x 88 mm x 200 mm, which consist of three unconfined specimens, six right angle specimens, and six rounded corner specimens were prepared and tested monotonically to failure. The experimental results show that the strength and ductility of HSC improved significantly by using rounded corner confined specimens and higher number of layer of confinements. This is due to more uniform confining pressure was exerted on entire surface of rounded corner confined specimens. The strength and ductility of the specimens can be improved up to 53.7% and 207.5% respectively.
This paper investigates the effect of high pressure liquid food compressibility onS. cerevisaeinactivation. Honey with various adjusted sugar with different values of compressibility was selected as a model food.S. cerevisiaecells in different honey concentrations (0-80°Brix), 600 MPa (at ambient temperature) showed an increasing resistance to inactivation with increasing °Brix.D-values ofS. cerevisiaeat 200, 400 and 600 MPa, for 20 min/80°Brix were 136.99 ± 7.97, 29.24 ± 6.44 and 23.47 ± 0.86 min, respectively. TheseD-values resulted the Z p -value of 526 ± 39 MPa. A significant correlation (p
A set of coupled particle and thermal transport equations is used to study a formation and sustainability of an edge transport barrier (ETB) in tokamak plasmas based on two-field bifurcation. The two transport equations are numerically solved for spatio-temporal profiles of plasma pressure and density. The plasma core transport includes both neoclassical and turbulent effects, where the latter can be suppressed by flow shear mechanism. The flow shear, approximated from the force balance equation, is proportional to the product of pressure and density gradients, resulting in non-linearity behaviors in this calculation. The main thermal and particle sources are assumed to be localized near plasma center and edge, respectively. It is found that the fluxes versus gradients regime illustrates bifurcation nature of the plasma. This picture of the plasma implies hysteresis properties in fluxes versus gradients space. Hence, near marginal point, the perturbation in thermal or particle sources can trigger an L-H transition. Due to hysteresis, the triggered H-mode can be sustained and the central plasma pressure and density can be enhanced.
Bandages are common in many health-related treatments, including management of edema of the lower limb where they may remain in place for several days. The behavior of 2 bandage fabrics was investigated after exposure for up to 5 days to a multiaxial extension laboratory setup on a tensile tester in compression mode. The fabrics were extended 20% and remained under that machine setting. Stress-relaxation over time was determined by analyzing the rate of change over 24 hours and over 5 days. Most change, a rapid drop in force, occurred during the first 15 minutes; thereafter, for the next 12-hour period, a slower rate of decrease was observed. Both fabrics continued to relax gradually during the next 12 hours and continued to do so for up to 5 days. Little further change was evident during the last 12 hours or so. This phenomenon suggests that rewrapping may be appropriate (albeit not practical) after 12 hours of compression therapy to optimize the compression given to the lower leg. Relaxation behavior of these 2 fabrics can be explained using the generalized Maxwell-Wiechert model.
Hypertension, defined as persistently elevated systolic blood pressure (SBP) >140 mmHg and/or diastolic blood pressure (DBP) at least 90 mmHg (International Society of Hypertension guidelines), affects over 1.5 billion people worldwide. Hypertension is associated with increased risk of cardiovascular disease (CVD) events (e.g. coronary heart disease, heart failure and stroke) and death. An international panel of experts convened by the International Society of Hypertension College of Experts compiled lifestyle management recommendations as first-line strategy to prevent and control hypertension in adulthood. We also recommend that lifestyle changes be continued even when blood pressure-lowering medications are prescribed. Specific recommendations based on literature evidence are summarized with advice to start these measures early in life, including maintaining a healthy body weight, increased levels of different types of physical activity, healthy eating and drinking, avoidance and cessation of smoking and alcohol use, management of stress and sleep levels. We also discuss the relevance of specific approaches including consumption of sodium, potassium, sugar, fibre, coffee, tea, intermittent fasting as well as integrated strategies to implement these recommendations using, for example, behaviour change-related technologies and digital tools.
Hypertension is an important public health issue due to its association with a number of serious diseases, including cardiovascular disease and stroke. The importance of evaluating hypertension taking into account different blood pressure (BP) profiles and BP variability (BPV) is increasingly being recognized, and is particularly relevant in Asian populations given the specific features of hypertension in the region (including greater salt sensitivity and a high rate of nocturnal hypertension). Ambulatory BP monitoring (ABPM) is the gold standard for diagnosing hypertension and assessing 24-hour BP and provides data on several important parameters that cannot be obtained using any other form of BP measurement. In addition, ABPM parameters provide better information on cardio- and cerebrovascular risk than office BP. ABPM should be used in all patients with elevated BP, particularly those with unstable office or home BP, or who are suspected to have white-coat or masked hypertension. ABPM is also an important part of hypertension diagnosis and monitoring in high-risk patients. ABPM needs to be performed using a validated device and good practice techniques, and has a role both in hypertension diagnosis and in monitoring the response to antihypertensive therapy to ensure strict BP control throughout the 24-hour period. Use of ABPM in clinical practice may be limited by cost and accessibility, and practical education of physicians and patients is essential. The ABPM evidence and practice points in this document are based on the Hypertension Cardiovascular Outcome Prevention and Evidence (HOPE) Asia Network expert panel consensus recommendations for ABPM in Asia.
Hypertension is a major public health problem in Malaysia. A survey was initiated to examine the association of modifiable and non-modifiable risk factors for hypertension in Perak, Malaysia.
Getting through major surgeries safely and timely with success and minimal complications is one of the great achievements of modern medicine. As the surgical techniques and the organs and systems involved become more varied, there are a number of important issues which determine the success of surgery. But one overriding theme is cardiovascular stability during and immediately after surgery.
OBJECTIVE: To determine the correlation between central venous pressure (CVP) measured by conventional central venous access and ultrasonographic measurement of internal jugular vein (IJV) height and inferior vena cava (IVC) diameter.
METHODS: A prospective, cross-sectional, convenience sampling observational study.
RESULTS: 25 patients from the Emergency Department (ED) Universiti Kebangsaan Malaysia Medical Centre (UKMMC) were studied between 1st March and 30th April 2013. The median age was 63 years (95% CI 54-67). There was a significant correlation between IJV height and CVP using central venous access (r=0.64 p<0.001). Correlation between IVC diameter in end expiration and CVP was 0.74 (p<0.001). An IJV height measurement >8cm predicted a CVP >8cm H2O (sensitivity 71.4%, specificity of 83.3%).
CONCLUSION: Measurement of IJV height and IVC diameter by ultrasonography correlates well with invasive CVP and is useful for the assessment of volume status in critically ill patients in the ED.
Study site: Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur
Conference abstract:
We aim to examine the relationship between visit-to-visit systolic blood pressure variability (BPV) and decline in renal function in patients with hypertension and determine the level of systolic BPV that contribute to significant renal function decline.
The objective of this paper is to model the extraction of carotenoid with supercritical carbon dioxide as the solvent. Experimental data for the high pressure vapour-liquid phase equilibrium of the binary system carbon dioxide-carotenoid was reviewed for the elevated temperatures of 313.15, 323.15, 333.15 K and pressures up to 500 bar. The experimental data was correlated and modeled using Redlich-Kwong equation of state and regular solution methods. The use of the equation of state as an empirical correlation for collating and predicting liquid-liquid and liquid-dense fluid equilibria is discussed. It was concluded that the estimation of some of the parameters required for these calculations would be difficult if the solute (carotenoid) was a complex substance about which little was known apart from its structural formula. An alternative procedure is to apply activity coefficient expression of the regular solution theory type to each phase. Calculations along these lines are described and the physical basis for applying these methods under the relevant conditions is discussed. The regular solution theory approach in particular was found to be encouraging for the mutual miscibility calculations for heavy components (such as carotenoid) particularly for substances sensitive to temperature, though the interaction parameters for he prediction activity coefficients must be regarded as pressure dependent.
A retrospective study was carried out to determine the distribution of intraocular pressure in normal patients who came for vision problems at the Optometry Clinic, Universiti Kebangsaan Malaysia (UKM) Kuala Lumpur Campus, and to determine the differences in intraocular pressure with respect to age, gender and race. The cohort consisted of 148 subjects divided into five groups with age ranged from 10 to 59 years. The inclusion criteria were, subjects had no sistemic or ocular disease, subjects were not taking any medication, visual acuity was 6/6 or better, refractive errors < ±6.00D, astigmatism < 2.00D, anisometropia <2.00D, and mean intraocular pressure measured using the X-PERT tonometer and taken between 9 am to 2 pm. Statistical analysis (ANOVA) showed the mean intraocular pressure without consideration for age, race or gender was 12.6 mmHg (SD ±2.5). There was no significant differences in intraocular pressure between right and left eyes, between different age groups and between different genders. However, the intraocular pressuse for the Chinese was found to be significantly higher than the Malays. It was found that the intraocular pressure of patients who came for vision problems at the Optometry Clinic UKM follows a normal distribution and there was no significant diference found between right and left eyes, between different age groups and genders. Race seemed to contribute to the differences in intraocular pressure. Keywords: Age; clinic population; genders; pressure; intraocular pressure; race
Study site: Optometry clinic, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia