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A numerical study is made on the entropy generation and magnetohydrodynamics natural convection of Al 2 O 3 -water non-homogeneous nanofluid inside a square enclosure equipped with a heated trapezoidal body. The Galerkin weighted residual finite element method is applied to solve the dimensionless governing equations within the utilized computational domain along with the algorithm of Newton–Raphson iteration that is used for simplifying the nonlinear terms in the equations. The characteristics of fluid flow fields, temperature distributions and entropy generation are studied for an enormous range of the Rayleigh number (10 3 ≤ R a ≤ 10 6) , volume fraction of nanoparticles ( 0 ≤ ϕ ≤ 0.04 ), Hartmann number (0 ≤ H a ≤ 50) , thermal conductivity of the trapezoidal solid body ( k w = 0.5 , 0.76, 1.95, 7 and 16) and the height of the trapezoidal solid body ( 0.15 ≤ D ≤ 0.45 ). It is shown that the streamlines pattern is more sensitive to the increase in the Hartmann number in comparison with the augmentation of the volume fraction of nanoparticles. Also, for a more thermodynamically optimized system, the higher Hartmann number at a higher solid volume fraction of nanofluid is recommended as they show less entropy generation. [ABSTRACT FROM AUTHOR]

Numerous studies have shown the interesting properties of trivalent lanthanide ions when doped in different types of glasses. This article examines the physical, structural and optical properties of series of strontium magnesium borate glasses doped with dysprosium ion (Dy3+) and synthesized using the melt-quenching technique. Physical and optical properties such as density, molar volume, ion concentration, molar refractivity, polaron radius, reflection loss, inter-nuclear distance and molar polarizability for each concentration of the dopant were calculated and reported. The results revealed diverse variations in density with other measured parameters. The amorphous behaviour of the glass samples was confirmed by X-ray diffraction spectroscopy. FTIR spectra measurements revealed the presence of various functional groups and their associated assignments. Optical properties of the activated glass samples with different concentrations of Dy3+ were determined by measuring the absorption and luminescence spectra in the visible region. The UV–Vis–NIR spectrophotometer analysis indicated the presence of eight inhomogeneous transition bands in various positions and intensities with hypersensitive transition at 1260 nm (6H15/2 → 6F11/2). The experimental oscillator strength (fexp) for each calculated absorption band showed higher magnitudes at hypersensitive transition. The optical energy band gap in the current work showed a decrease in values with increasing ion concentrations. The luminescence spectra of the prepared glass phosphors showed three unique transitions at 4F9/2 → 6H15/2 (490 nm), 4F9/2 → 6H13/2 (585 nm) and 4F9/2 → 6H11/2 (689 nm). [ABSTRACT FROM AUTHOR]

In this study, the conjugate natural convection in a square cavity filled with Al 2 O 3 –water nanofluid with an inner conducting solid block is studied numerically using nonhomogeneous Buongiorno's two-phase model. The left wall of the cavity is partially heated and the remaining parts of the wall are adiabatic, while the right wall is fully cooled. The top and bottom horizontal walls are adiabatic. The numerical simulations are based on the finite difference method. The results are simulated for various values of the nanoparticle volume fraction (0 ≤ ϕ ≤ 0.04) , Rayleigh number (10 2 ≤ R a ≤ 10 6) , thermal conductivity of the conjugate square (k w = 0.28 , 0.76 , 1.95 , 7.0) and 16.0 (epoxy: 0.28, brickwork: 0.76, granite: 1.95, solid rock: 7, stainless steel: 16), the size of the inner solid (0 ≤ D ≤ 0.7) , and the length of the heater ( 0.1 ≤ H ≤ 1.0 ). The numerical results for the average and local Nusselt numbers, isotherms, distribution of nanoparticles, and streamlines are presented graphically. The findings indicate that increasing the average solid volume fraction and the size of the solid block as well as the thermal conductivity will enhance the rate of the heat transfer at low values of Rayleigh number R a = 10 3 . On the other hand, increasing these parameters at high values of Rayleigh number ( R a > 10 5 ) decreases the average Nusselt number. [ABSTRACT FROM AUTHOR]

The present study investigates the conjugate heat transfer in a square cavity heated by a triangular solid and saturated with Al2O3-water nanofluid. Two-phase Buongiorno's model is used for modeling the nanofluid heat transfer. The finite element method is used for numerical solution of the dimensionless governing equations subject to the boundary conditions. Comparisons of the proposed method with previously published experimental and numerical works show a good agreement. The effects of some parameters such as the Rayleigh number, thermal conductivity ratio, dimensionless triangular wall thickness and nanofluid volume fraction on heat transfer and nanoparticle distributions are completely studied and discussed. The results show clockwise rotations for streamlines and nanoparticle migration. Also the Nusselt number increases with the nanofluid volume fraction. A continuous reduction is seen for the mean Nusselt number by increasing the dimensionless triangular wall thickness for all the considered values of the Rayleigh number. [ABSTRACT FROM AUTHOR]

This paper investigates a steady mixed convection in a lid-driven square cavity subjected to an inclined magnetic field and heated by corner heater with an inserted square solid block. Water-Al2O3 nanofluid fills the cavity based on Buongiorno's two-phase model. A corner heater is configured in the left lower corner of the cavity by maintaining 40% of the bottom and vertical walls at constant hot temperature. The top horizontal wall is moving and maintained at a constant low temperature. The remainder walls are thermally insulated. The governing equations are solved numerically using the finite element method. The governing parameters are the nanoparticles volume fraction (0≤ϕ≤0.04), Reynolds number (1≤Re≤500), Richardson number (0.01≤Ri≤100), Hartmann number (0≤Ha≤50) and the size of the inner solid (0.1≤D≤0.7). The other parameters: the Prandtl number, Lewis number, Schmidt number, ratio of Brownian to thermophoretic diffusivity and the normalized temperature parameter, are fixed at Pr=4.623, Le=3.5×105, Sc=3.55×104, NBT=1.1 and δ=155, respectively. The inclination of the magnetic field is fixed at γ=π4. Results show that at low Reynolds number, the increase in nanoparticles loading more the 2% becomes useless. It is also found that a big size of the solid block can augment heat transfer in the case of high values of both the Reynolds and Richardson numbers. [ABSTRACT FROM AUTHOR]

A study on the pattern of mineral lick use by the Northwest Bornean orangutans ( Pongo pygmaeus pygmaeus) in the Lanjak Entimau Wildlife Sanctuary was carried out from February 2009 to December 2010. A camera trapping method was employed to investigate orangutan mineral lick visitation. The camera traps recorded a total of 263 orangutan visitations or 1.3 % from an overall 22,521 photographs taken. More visits were recorded between August 2009 and March 2010 which coincides with the dipterocarp flowering and fruiting season. Pairs and females with infants were recorded as the most regular visitors compared to pairs and females without infants and solitary males. The visitation time and duration varied among mineral licks and orangutan classes while the interval day visit showed that pairs and females with newborn infants visit the mineral licks continuously from the first day of the study to the tenth day. [ABSTRACT FROM AUTHOR]

The buoyant Marangoni convection heat transfer in a differentially heated cavity is numerically studied. The cavity is filled with water-Ag, water-Cu, water-AlO, and water-TiO nanofluids. The governing equations are based on the equations involving the stream function, vorticity, and temperature. The dimensionless forms of the governing equations are solved by the finite difference (FD) scheme consisting of the alternating direction implicit (ADI) method and the tri-diagonal matrix algorithm (TDMA). It is found that the increase in the nanoparticle concentration leads to the decrease in the flow rates in the secondary cells when the convective thermocapillary and the buoyancy force have similar strength. A critical Marangoni number exists, below which increasing the Marangoni number decreases the average Nusselt number, and above which increasing the Marangoni number increases the average Nusselt number. The nanoparticles play a crucial role in the critical Marangoni number. [ABSTRACT FROM AUTHOR]

The mixed convection boundary layer flow of a micropolar nanofluid near a stagnation point along a vertical stretching sheet is investigated. The transformed nonlinear system of ordinary differential equations are solved using the shooting technique with Runge-Kutta Fehlberg method. Comparisons between present and previous results in the absence of nanofluid are tabulated. Several flow velocity, temperature and nanoparticle volume fraction profiles are visualized. The graphical variations of the reduced skin friction coefficient, the reduced Nusselt number and the reduced Sherwood number of both assisting and opposing flows are also presented. The effects of material parameter and microrotation on the Nusselt number are similar with the findings of other researchers. The presence of slip velocity between the base fluid and the nanoparticles has significant impact on the heat transfer enhancement of the stagnation flow of micropolar nanofluid. [ABSTRACT FROM AUTHOR]

Conjugate natural convection in a square porous enclosure sandwiched by finite walls under the influence of non-uniform heat generation and radiation is studied numerically in the present article. The horizontal heating is considered, where the vertical walls heated isothermally at different temperatures, while the horizontal walls are kept adiabatic. The Darcy model is used in the mathematical formulation for the porous layer and finite difference method is applied to solve the dimensionless governing equations. The governing parameters considered are the ratio of wall thickness to its width $$(0.02 \le D \le 0.3)$$ , the wall to porous thermal conductivity ratio $$(0.1 \le k_\mathrm{r} \le 10.0)$$ , the internal heating $$(0 \le \gamma \le 5)$$ , and the local heating exponent parameters $$(1 \le \lambda \le 20)$$ . It is found that the average Nusselt number on the hot and cold interfaces increases with increasing the radiation intensity. Very high non-uniformity heating does not affect the average Nusselt number at very thick walls. [ABSTRACT FROM AUTHOR]

Thermo-rheological effect of temperature-dependent viscous fluid saturating a porous medium has been studied in the presence of imposed time periodic gravity field and internal heat source. Weak nonlinear stability analysis has been performed by using the power series expansion in terms of the amplitude of gravity modulation, which is considered to be small. Nusselt number is calculated numerically using Ginzburg-Landau equation. The nonlinear effects of thermo-mechanical anisotropies, internal heat source parameter, Vadász number, thermo-rheological parameter and amplitude of gravity modulation have been obtained and depicted graphically. Streamlines and isotherms have been drawn for different times. Comparisons have been made between various physical systems. [ABSTRACT FROM AUTHOR]

Effect of rotation on linear and nonlinear instability of cross-diffusive convection in an anisotropic porous medium saturated with Newtonian fluid has been investigated. Normal mode technique has been used for linear stability analysis, however nonlinear analysis is done using spectral method, involving only two terms. The Darcy model with Coriolis terms, has been employed in the momentum equation. Nonlinear analysis is used to find the thermal and concentration Nusselt numbers. The effects of various parameters, including Soret and Dufour parameters, on stationary and oscillatory convection, have been obtained, and shown graphically. [ABSTRACT FROM AUTHOR]

The effects of time-periodic boundary temperatures and internal heating on Nusselt number in the Bénard-Darcy convective problem has been considered. The amplitudes of temperature modulation at the lower and upper surfaces are considered to be very small. By performing a weakly non-linear stability analysis, the Nusselt number is obtained in terms of the amplitude of convection, which is governed by the non-autonomous Ginzburg-Landau equation, derived for the stationary mode of convection. The effects of internal Rayleigh number, amplitude and frequency of modulation, thermo-mechanical anisotropies, and Vadasz number on heat transport have been analyzed and depicted graphically. Increasing values of internal Rayleigh number results in the enhancement of heat transport in the system. Further, the study establishes that the heat transport can be controlled effectively by a mechanism that is external to the system. [ABSTRACT FROM AUTHOR]

Darcy-Bénard convection in a square porous enclosure with a localized heating from below and lateral cooling is studied numerically in the present paper. A finite-thickness bottom wall is locally heated, the top wall is kept at a lower temperature than the bottom wall temperature, and the lateral walls are cooled. The finite difference method has been used to solve the dimensionless governing equations. The analysis in the undergoing numerical investigation is performed in the following ranges of the associated dimensionless groups: the heat source length- $${0.2\leq H \leq 0.9}$$, the wall thickness- $${0.05\leq D \leq 0.4}$$, the thermal conductivity ratio- $${0.8\leq K_{\rm r} \leq 9.8}$$, and the Biot number- $${0.1\leq Bi \leq 1.1}$$. It is observed that the heat transfer rate could increase with increasing heat source lengths, thermal conductivity ratio, and cooling intensity. There exists a critical wall thickness for a high wall conductivity below which the increasing wall thickness increases the heat transfer rate and above which the increasing wall thickness decreases the heat transfer rate. [ABSTRACT FROM AUTHOR]

In this article we study the combined effect of internal heating and time-periodic gravity modulation on thermal instability in a closely packed anisotropic porous medium, heated from below and cooled from above. The time-periodic gravity modulation, considered in this problem can be realized by vertically oscillating the porous medium. A weak non-linear stability analysis has been performed by using power series expansion in terms of the amplitude of gravity modulation, which is assumed to be small. The Nusselt number has been obtained in terms of the amplitude of convection which is governed by the non-autonomous Ginzburg-Landau equation derived for the stationary mode of convection. The effects of various parameters such as; internal Rayleigh number, amplitude and frequency of gravity modulation, thermo-mechanical anisotropies, and Vadász number on heat transport has been analyzed. It is found that the response of the convective system to the internal Rayleigh number is destabilizing. Further it is found that the heat transport can also be controlled by suitably adjusting the external parameters of the system. [ABSTRACT FROM AUTHOR]

Effects of a conductive wall on natural convection in a square porous enclosure having internal heating at a rate proportional to a power of temperature difference is studied numerically in this article. The horizontal heating is considered, where the vertical walls heated isothermally at different temperatures while the horizontal walls are kept adiabatic. The Darcy model is used in the mathematical formulation for the porous layer and finite difference method is applied to solve the dimensionless governing equations. The governing parameters considered are the Rayleigh number (0 ≤ Ra ≤ 1000), the internal heating and the local exponent parameters (0 ≤ γ ≤ 5), (1 ≤ λ ≤ 3), the wall to porous thermal conductivity ratio (0.44 ≤ Kr ≤ 9.9) and the ratio of wall thickness to its width (0.02 ≤ D ≤ 0.5). The results are presented to show the effect of these parameters on the fluid flow and heat transfer characteristics. It is found a strong internal heating can generate significant maximum fluid temperature more than the conductive solid wall. Increasing value thermal conductivity ratio and/or decreasing the thickness of solid wall can increase the maximum fluid temperature. It is also found that at very low Rayleigh number, the heat transfer across the porous enclosure remain stable for any values of the thermal conductivity ratio. [ABSTRACT FROM AUTHOR]

Conjugate natural convection-conduction heat transfer in a square porous enclosure with a finite-wall thickness is studied numerically in this article. The bottom wall is heated and the upper wall is cooled while the verticals walls are kept adiabatic. The Darcy model is used in the mathematical formulation for the porous layer and the COMSOL Multiphysics software is applied to solve the dimensionless governing equations. The governing parameters considered are the Rayleigh number (100 ≤ Ra ≤ 1000), the wall to porous thermal conductivity ratio (0.44 ≤ K ≤ 9.90) and the ratio of wall thickness to its height (0.02 ≤ D ≤ 0.4). The results are presented to show the effect of these parameters on the heat transfer and fluid flow characteristics. It is found that the number of contrarotative cells and the strength circulation of each cell can be controlled by the thickness of the bottom wall, the thermal conductivity ratio and the Rayleigh number. It is also observed that increasing either the Rayleigh number or the thermal conductivity ratio or both, and decreasing the thickness of the bounded wall can increase the average Nusselt number for the porous enclosure. [ABSTRACT FROM AUTHOR]

This research studied the influence of internal heat generation on flow and heat transfer in a thin liquid film on an unsteady stretching sheet. The velocity and temperature fields were solved using the Homotopy Analysis Method (HAM), taking a general surface temperature into consideration. The analytical series solution are presented and the numerical results obtained are tabulated. The effects of unsteadiness parameter, Prandtl number and temperature-dependent parameter in this study are discussed and presented graphically via the velocity and temperature profiles. [ABSTRACT FROM AUTHOR]

The problem of unsteady natural convection in a square region filled with a fluid-saturated porous medium having non-uniform internal heating and heated laterally is considered. The heated wall surface temperature varies sinusoidally with the time about fixed mean temperature. The opposite cold wall is maintained at a constant temperature. The top and bottom horizontal walls are kept adiabatic. The flow field is modelled with the Darcy model and is solved numerically using a finite difference method. The transient solutions obtained are all periodic in time. The effect of Rayleigh number, internal heating parameters, heating amplitude and oscillating frequency on the flow and temperature field as well as the total heat generated within the convective region are presented. It was found that strong internal heating can generate significant maximum fluid temperatures above the heated wall. The location of the maximum fluid temperature moves with time according to the periodically changing heated wall temperature. The augmentation of the space-averaged temperature in the cavity strongly depends on the heating amplitude and rather insensitive to the oscillating frequency. [ABSTRACT FROM AUTHOR]

The effects of a magnetic field on the route to chaos in a fluid-saturated porous layer were investigated based on the approach of dynamical systems. A low dimensional Lorenz-like model was obtained using Galerkin truncated approximation. The presence of a magnetic field helped delay the convective motion. The transition from steady convection to chaos via a Hopf bifurcation produced a limit cycle which may be associated with a homoclinic explosion at a slightly subcritical value of the Rayleigh number. [ABSTRACT FROM AUTHOR]

Feedback control on thermal convection in a fluid-saturated porous medium is investigated based on the dynamical systems approach. A low dimensional Lorenz-like model was obtained using the Galerkin-truncated approximation. The possible suppression or enhancement of chaotic convection is demonstrated when the fluid layer is subjected to feedback control in a low-dimensional framework. [ABSTRACT FROM AUTHOR]

In this paper, the homotopy analysis method (HAM) and its modification (MHAM) are applied to solve the nonlinear time- and space-fractional modified Korteweg-de Vries (fmKdV). The fractional derivatives are described by Caputo’s sense. Approximate and exact analytical solutions of the fmKdV are obtained. The MHAM in particular overcomes the computing difficulty encountered in HAM. Convergence theorems for both the homogeneous and non-homogeneous cases are given. The results of applying this procedure to the studied cases show the high accuracy and efficiency of the approach. [ABSTRACT FROM AUTHOR]

In this paper, the homotopy analysis method (HAM) is applied to obtain approximate analytical solutions of the generalized Burgers-Huxley and Huxley equations. The series solution is developed and given explicitly. The initial approximation can be freely chosen with possible unknown constants which can be determined by imposing the boundary and initial conditions. The comparison of the HAM results with the variational iteration method (VIM) results is made. It is shown, in particular, that the VIM solutions are only special cases of the HAM solutions. [ABSTRACT FROM AUTHOR]

Differential equations of fractional order appear in many applications in physics, chemistry and engineering. An effective and easy-to-use method for solving such equations is needed. In this paper, series solutions of the FDEs are presented using the homotopy analysis method (HAM). The HAM provides a convenient way of controlling the convergence region and rate of the series solution. It is confirmed that the HAM series solutions contain the Adomian decomposition method (ADM) solution as special cases. [ABSTRACT FROM AUTHOR]

Linear stability theory is applied to the problem of the onset of oscillatory Marangoni convection in a horizontal layer of electrically conducting fluid heated from below in the presence of a vertical magnetic field. The fluid layer is bounded from below by a rigid boundary and from above by a deformable free surface. The critical Marangoni number M[subc], the critical wavenumber a[subc] and the critical frequency w[subc] are obtained for wide ranges of the Prandtl number P[sub1], the magnetic Prandt[subl] number P[sub2], the crispation number C[subr] and the Chandrasekhar number Q. We present numerically a necessary and sufficient condition for oscillatory Marangoni convection to occur. [ABSTRACT FROM AUTHOR]

OBJECTIVE:: To determine the glycaemic index of one variety of date, alone and in mixed meals with plain full-milk yoghurt. DESIGN:: An experimental study involving the measurement of the glycaemic responses of participants to the ingestion of dates, alone and with yoghurt SETTING:: Within the Department of Family Medicine, Faculty of Medicine and Health Sciences, UAE University SUBJECTS:: Healthy male and female volunteers aged 32-67 y. INTERVENTION:: Glycaemic responses to date and date/yoghurt meal ingestion were plotted for each subject. Glycaemic indexes were calculated as the ratios of the incremental areas under these response curves to those for glucose ingestion. Results are presented using means and standard deviations. Glycaemic indexes were compared using paired t-tests. RESULTS:: Mean glycaemic indexes of the dates were 47.2, 45.3, 35.5, 37.3, 28.9 for rutab, traditionally stored, commercial, rutab/yoghurt and commercial tamer/yoghurt preparations, respectively. There was a significant difference between the results for rutab vs commercial tamer dates (P<0.05), but other comparisons failed to reach statistical significance. CONCLUSIONS:: Khalas dates, when eaten alone or in mixed meals with plain yoghurt have low glycaemic indexes. The consumption of dates may be of benefit in glycaemic and lipid control of diabetic patients. The consumption of dates in mixed meals with yoghurt appears to have, at most, a minimal effect on the glycaemic index. SPONSORSHIP:: This study was not financed by any grant or institution.European Journal of Clinical Nutrition (2003) 57, 427-430. doi:10.1038/sj.ejcn.1601535 [ABSTRACT FROM AUTHOR]

Examines the analytical description of the marginal mode for onset of oscillatory Marangoni convection. Presence of uniform internal heat generation in a horizontal fluid layer; Description of the asymptotic limit of short waves.

Examines the effect of a uniform vertical magnetic field om the onset of oscillatory Marangoni convection in a horizontal layer of conducting fluid. Presence of magnetic field on the preferred mode of instability; Stabilization of magnetic field; Details of the Marangoni convection.

In this paper we use classical linear stability theory to analyse the onset of thermocapillary-driven Marangoni convection in a semi-infinitely deep layer of quiescent fluid. We use a combination of analytical and numerical techniques to obtain for the first time a detailed description of the marginal stability curves for the onset of oscillatory convection. We perform a comprehensive asymptotic analysis of the marginal curves in the limits of both long-wave and short-wave perturbations and present the results of numerical calculations which illustrate the effect of varying the problem parameters on the marginal curves and hence on the critical Marangoni number, frequency of oscillation and wavenumber for the onset of convection. [ABSTRACT FROM AUTHOR]

Analysis of renal stones may help in elucidating the pathogenesis of nephro-lithiasis. This study compared the use of 2 methods for the analysis of renal stones. One method is qualitative dry ‘spot tests’ whereas the other is quantitative ‘wet chemistry.’ In the wet chemistry method, dissolved stone material were analysed using automated chemistry analysers, whereas, the dry method involved spot colour end-point detection. Stones (n=64) were analysed by both methods. The majority of stones were calcium oxalate as determined by wet chemistry (57.4 per cent) and spot tests (50.0 per cent). Fewer mixed stones were obtained by the wet chemistry method (16.8 per cent) compared with the spot tests method (39.0 per cent), whereas, more uric acid stones were obtained by the wet chemistry method (5.6 per cent) compared with the spot tests method (1.9 per cent). ‘Pure’ calcium phosphate stones (3.0 per cent) were only obtained by the wet chemistry method. In the wet chemistry method, dissolved stone material did not show significant deterioration on storage for up to 9 days. [ABSTRACT FROM AUTHOR]

Granulocyte-macrophage colony-stimulating factor (GM-CSF), one of the haemopoietic growth factors, has rarely been detected in human serum. It has, therefore, been suggested that a paracrine model can explain its behaviour where the substance is produced and acts locally. An alternative explanation might be due to blood sampling time with GM-CSF concentrations undetectable at the nadir of secretion. We hypothesised that endogenous production of GM-CSF in humans is subject to diurnal rhythm. Blood samples were obtained from 17 healthy individuals and 17 neutropenic hospitalised patients with haematological malignancies on myelosuppressive therapy at 6, 12, 18 and 24 hours. In the neutropenic patients, samples were collected at the nadir of the neutrophil count (ANC <0.2 × 109/L). Serum was assayed for GM-CSF levels using an enzyme-linked immunosorbent assay method. There were significant differences in the mean levels of GM-CSF within the two groups (P<0.001). In normal subjects, peak GM-CSF levels were reached at six hours (mean = 10.1 pg/ml). Peak levels were reached in hospitalised neutropenic patients at 18 hours (mean = 13.7 pg/ml). The difference between the peak GM-CSF levels in the two groups was not significant (P=0.11). On factorial design analysis, there was a significant interaction between the time of blood collection and the subject groups (P<0.001). Our data are consistent with a diurnal secretion pattern for GM-CSF in both normal and neutropenic patients. As this finding might have practical implications, including timing of administration of GM-CSF in neutropenic patients, further studies are suggested. [ABSTRACT FROM AUTHOR]

Heat Stroke (HS) is frequently fatal illness that usually occurs episodically as clusters of patients presenting to the emergency room. We have studied 26 patients with HS incurred during the religious pilgrimage to Makkah at (0, 6, 12, 24 hr) and found that the level of IL-Ira, TNF SR II and IL-6 are elevated. It appears such elevation are required for and are part of acute phase response and recovery. However markedly elevated cytokines are associated with mortality. We also found the precursors to the hormone calcitonin: Procalcitonin are greatly increased in patients with this condition. Although serum levels are high upon admission (3.4±1.0 ng/ml vs 0.17±0.04 ng/ml for a febrile emergency room control (P=0.012), even higher levels occured at 6 hours 25.1±6.4 ng/ml, (P<0.0001). Among the 6 patients who died 4 of them had levels indistinguishable from control subjects, the other 2 patients who had high levels, had additional medical complications. Chi-square analysis of categorized Pro CT revealed a significant positive correlation between Pro CT and survival. Our study shows that the level of IL-Ira, TNF SR II and IL-6 are increased in HS and associated with mortality and also it may suggest that the hyperprocalcitoninemia may be related to the post-injury cytokine cascade. The mechanism by which hyperprocalcitoninemic response is elicited in surviving HS patients, but fail to occur in most of those who do not survive requires further study. [ABSTRACT FROM AUTHOR]