Ability Of Fluid Research Articles

English

The aim of this paper was to prepare and evaluate the feasibility of hydrophobically modified chitosan for hemostatic use. Chitosan was grafted with different branched chains by schiff reaction with salicylaldehyde and dodecyl aldehyde and followed by reductive amination with NaBH4. Elemental analysis was carried out to calculate the degree of substitution (DS) for NH2. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests were used to confirm the composition and structure of modified chitosan products. Rheological experiments were performed to evaluate the ability of fluids including modified chitosan and its mixtures with heparinized blood to form gels. Dynamic blood coagulation experiments were tested to compare the hemostatic property of chitosan with its derivatives in vitro. The results demonstrated that orhto-hydroxytoluene and dodecyl were grafted into the backbone of chitosan successfully and the crystallity of chitosan was changed sligtly. Although the DS of ortho-hydroxytoluene chitosan was higher than that of dodecyl chitosan, the later had better gel-forming ability and lower absorbency at specific wavelength of haemoglobin. Dodecyl chitosan had great potential as an ideal candidate for local hemostasis.   Key words: Ortho-hydroxytoluene chitosan, dodecyl chitosan, rheological property, dynamic blood coagulation.

Human amniotic fluid derived cells can competently substitute dermal fibroblasts in a tissue-engineered dermo-epidermal skin analog

Human amniotic fluid comprises cells with high differentiation capacity, thus representing a potential cell source for skin tissue engineering. In this experimental study, we investigated the ability of human amniotic fluid derived cells to substitute dermal fibroblasts and support epidermis formation and stratification in a humanized animal model. Dermo-epidermal skin grafts with either amniocytes or with fibroblasts in the dermis were compared in a rat model. Full-thickness skin wounds on the back of immuno-incompetent rats were covered with skin grafts with (1) amniocytes in the dermis, (2) fibroblasts in the dermis, or, (3) acellular dermis. Grafts were excised 7 and 21days post transplantation. Histology and immunofluorescence were performed to investigate epidermis formation, stratification, and expression of established skin markers. The epidermis of skin grafts engineered with amniocytes showed near-normal anatomy, a continuous basal lamina, and a stratum corneum. Expression patterns for keratin 15, keratin 16, and Ki67 were similar to grafts with fibroblasts; keratin 1 expression was not yet fully established in all suprabasal cell layers, expression of keratin 19 was increased and not only restricted to the basal cell layer as seen in grafts with fibroblasts. In grafts with acellular dermis, keratinocytes did not survive. Dermo-epidermal skin grafts with amniocytes show near-normal physiological behavior suggesting that amniocytes substitute fibroblast function to support the essential cross-talk between mesenchyme and epithelia needed for epidermal stratification. This novel finding has considerable implications regarding tissue engineering.

Design and Test of Piezoelectric Resonant Diaphragm Air Pump

To improve the driving ability of gas and light fluid which is sensitive to the temperature change, based on the system resonant principle a novel kind of piezoelectric resonant diaphragm air pump has been proposed. Experimental results indicate that the maximum flow rate is 1650ml/min when the sinusoidal AC driving voltage is 200v, the vibrating spring thickness is 0.6mm, the adjusting spring thickness is 1.4mm, and it was 0.5 as the radius ratio of the rigidity transfer vibration piston and the diaphragm.

Solubility of xenotime in a 2 M HCl aqueous fluid from 1.2 to 2.6 GPa and 300 to 500 C

Constraining mass transfer of the rare earth elements (REE) and high field strength elements (HFSE) from subducted oceanic crust and metasediments to the mantle wedge is fundamental toward interpreting processes that affect trace element mobility in subduction zone environments. Experimental studies of the partitioning of trace elements involving aqueous fluids at P-T conditions appropriate for slab-mantle wedge conditions are complicated by the difficulties in retrieving the fluid. Here we present the results from an application of an in situ technique that permits quantitative determination of element concentrations in aqueous fluid at geologically relevant supercritical conditions. We focus on pressures and temperatures appropriate for devolatilization-induced element transfer in subduction zone environments, and conditions obtained during regional metamorphism. In this study, we used a hydrothermal diamond-anvil cell (HDAC) and in situ synchrotron X-ray fluorescence (SXRF) to quantify the concentration of Y, an important trace element often used as a proxy for the heavy REE in geologic systems, in a xenotime-saturated 2 M HCl-aqueous fluid at 1.19 to 2.6 GPa and 300–500 °C. At these pressures and temperatures the solubility of yttrium ranges from 2400 to 2850 ppm. We find that the concentration of Y decreases with increasing fluid density. These new data, combined with published data generated from experiments done at lower pressure, in fluids of nearly identical composition and also NaCl-H 2 O fluids, constrain the effects of pressure and temperature on the ability of aqueous fluid containing Cl to scavenge and transport Y and, by analogy, the HREE. Although the physical properties of Y are similar to the high field strength elements, Y exhibits geochemical behavior that is analogous to the heavy rare earth elements (HREE).

Urinary Plasmin Activates Collecting Duct ENaC Current in Preeclampsia

In nephrotic syndrome, plasminogen is aberrantly filtered from plasma to the urinary space and activated along the tubular system. In vitro, plasmin increases ENaC current by proteolytic cleavage of the γ-subunit. It was hypothesized that preeclampsia is associated with plasmin-dependent ability of tubular fluid to activate ENaC. Urine was sampled from 16 preeclamptic (PE) patients and 17 normotensive pregnant women (Ctrl). Urine was analyzed for plasmin(ogen), creatinine, albumin, aldosterone, Na(+), K(+), proteolytic activity, and for its effect on inward current in cortical collecting duct cells (M1 cells) by whole-cell patch clamp. In PE, urine plasmin(ogen): creatinine ratio was elevated 40-fold (geometric mean, 160 versus 4 µg/g; P<0.0001) and urine aldosterone: creatinine ratio was suppressed to 25% of Ctrl (geometric mean, 27 versus 109 µg/g; P<0.001). A significant negative correlation was found in PE between urinary plasmin(ogen) and aldosterone (P<0.05). In PE, proteolytic activity was detected at 90 to 75 kD by gelatin zymography in 14 of 16 patients and confirmed by serine protease assay. Immunoblotting showed active plasmin in PE urine. Whole-cell inward current increased in M1 cells on exposure to urine from PE (173±21%; n=6; P<0.001). The increase in current was abolished by amiloride (2 μmol/L; P<0.001), α(2)-antiplasmin (1 μmol/L; P<0.001), and heat denaturation (P<0.001). Preeclampsia is associated with urinary excretion of plasmin(ogen) and plasmin-dependent activation of ENaC by urine. Proteolytic activation of ENaC by plasmin may contribute to Na(+) retention and hypertension in preeclampsia.

Acute injury affects lubricin expression in knee menisci: An immunohistochemical study

The aim of this study was to investigate for the first time lubricin expression in intact menisci and in menisci from patients with recent knee joint injury using histology, immunohistochemistry, Western blotting and gene expression analysis, to provide insights into pathological processes affecting meniscal tissue. Lubricin expression was studied in vivo in 20 patients (14 males and 6 females) with recent joint injury subjected to arthroscopic partial meniscectomy and in vitro in fibroblast-like cells from meniscus tissue to establish whether it is down-regulated following acute traumatic knee injury. The control group consisted of cadaver donors with normal menisci. Histology demonstrated a normal tissue without structural changes in control samples and structural alterations and clefts in injured menisci. Very strong lubricin immunohistochemical staining was observed in intact menisci; in contrast weak staining was seen in injured menisci. Western blot and mRNA expression analysis also demonstrated strong lubricin expression in control cells and a negligible amount of lubricin in injured fibroblast-like cells. Our data provide information concerning the immediate in vivo response to injury of human knee menisci by documenting early changes in the boundary-lubricating ability of synovial fluid and articular cartilage integrity. These findings may provide the biological basis for developing novel medical therapies to be applied before surgical treatment to preserve tissue function and prevent cartilage damage.

Characterization of porous materials using ultrasonic slow wave

Porous materials are critical engineering components in many process industries. Although porous materials have been successfully utilized in many areas, characterization of porous structures is still a significant problem limiting the applications of porous materials, especially when the application involves the change of porous structure. Ultrasonic techniques have been reported for successful applications on material characterization, including porous materials. This research utilized an acoustic technique for permeability measurement by measuring the critical wave number of Biot’s slow longitudinal wave. The slow longitudinal wave can serve as an important tool for investigating the ability of fluids to penetrate into porous materials. Since the slow longitudinal wave is associated with out-of-phase movement of the pore fluid relative to the matrix structure, it is very sensitive to the permeability of the porous formation. In Biot’s theory the slow wave is highly attenuated below a critical frequency. The critical wave number can be directly related to the permeability of porous materials. The measurement of the critical wave number provides a unique method to obtain the permeability measurement, which can be apply to structure monitoring, quality control, etc.

Angiogenin expression in burn blister fluid: Implications for its role in burn wound neovascularization

Deep partial thickness burn (DPTB) wound fluids have a greater propensity for establishing neovascularization than did superficial partial thickness burn (SPTB) wound fluids in our previous study. To investigate the factors responsible for this activity, cytokine array and enzyme-linked immunosorbent assay were used to perform an expression analysis of angiogenic factors in burn fluid. Although present in approximately equal amounts in both SPTB and DPTB blister fluids from burn patients, angiogenin does appear to be involved in the ability of DPTB blister fluid to promote neovascularization in vitro and in vivo. Angiogenin alone was sufficient to induce endothelial differentiation of circulating angiogenic cells (CAC) without vascular endothelial growth factor A involvement. In addition, angiogenin was positively associated with CAC differentiation in the burn blister fluid. Blocking the effect of angiogenin in burn blister fluids resulted in a significant reduction of endothelial cell proliferation, CAC differentiation, and new blood vessels formation in vivo. Moreover, immunohistochemistry revealed that high angiogenin expression colocalizes with high vascularity in human burn wounds at day 7, further supporting our hypothesis that angiogenin is involved in burn wound neovascularization.

Androgen depletion augments antibacterial prostate host defences in rats

The defence of the male reproductive tract against microorganisms is critical for fertilization. The prostate gland has been reported to express several molecules of the innate immune system. However, little information is available about how androgens may modulate host defences within the prostate. We therefore aimed to examine in the rat the expression of the TLR4 system, which is strongly involved in pathogen recognition, and the secretion of the antibacterial substances rBD-1 and SP-D after androgen withdrawal. Immunoblotting and immunocytochemical analysis revealed a time-dependent increase in these molecules after orchiectomy, with epithelial and stromal cells being an important source of prostatic host defence proteins. In view of this, we evaluated the potential improvement in antibacterial ability of the prostatic fluid from orchiectomized animals ex vivo. Only samples from rats at 5 days post-orchiectomy showed a slight inhibition of Escherichia coli growth. Finally, E. coli was inoculated into the ventral prostate of orchiectomized or control rats, with bacterial growth being counted at 5 days after infection. Animals with androgen depletion presented a lower bacterial count, and showed few histological signs of prostatic inflammation compared with controls. In vitro studies confirmed that isolated lipopolysaccharide (LPS)-treated prostatic cells in the absence of testosterone increased SP-D. Moreover, media from these cells showed a higher antimicrobial activity than supernatants from testosterone- and LPS-treated cells. Our findings indicate that testosterone maintains a reduced expression of key elements for innate immunity and diminishes the antibacterial ability of the rat prostate. These data may represent an important mechanism underlying the immunosuppressive activity of testosterone in the gland. However, this immunosuppressive function of androgens is understandable as a means of avoiding uncontrolled immune responses against the haploid male gamete in the reproductive tract.

Effect of supercritical conditions upon catalyst deactivation in the hydrogenation of naphthalene

The hydrogenation of naphthalene in cyclohexane solvent was studied over a NiMo/Al2O3 catalyst operated in a fixed bed reactor. The effect of operating under sub- and supercritical conditions was investigated at temperatures 250–300°C and pressures 20–90bar. Naphthalene/cyclohexene flows of 0.5–2.5mLmin−1 and hydrogen flows of 2–10mLmin−1 were investigated. When operating in the supercritical region with high hydrogen/liquid feed ratio, no significant deactivation occurred over 6h of operation. A strong effect of pressure upon conversion was observed, with naphthalene conversion close to 100% at 60bar, 300°C. Trans-decalin was the favoured product over most of the range of conditions investigated. When operating at low hydrogen/liquid feed ratio, initial conversion of naphthalene was 90–95%, declining to 58% at supercritical conditions and 35% at subcritical conditions after 7h. Coke deposition was 38% lower at supercritical conditions. The ability of supercritical fluids to delay catalyst deactivation is considered, together with interesting changes to product distribution that occur under these conditions.

Solid-Phase Immunoglobulins IgG and IgM Activate Macrophages with Solid-Phase IgM Acting via a Novel Scavenger Receptor A Pathway

IgG may accelerate atherosclerosis via ligation of proinflammatory Fcγ receptors; however, IgM is unable to ligate FcγR and is often considered vasculoprotective. IgM aggravates ischemia-reperfusion injury, and solid-phase deposits of pure IgM, as seen with IgM-secreting neoplasms, are well known clinically to provoke vascular inflammation. We therefore examined the molecular mechanisms by which immunoglobulins can aggravate vascular inflammation, such as in atherosclerosis. We compared the ability of fluid- and solid-phase immunoglobulins to activate macrophages. Solid-phase immunoglobulins initiated prothrombotic and proinflammatory functions in human macrophages, including NF-κB p65 activation, H(2)O(2) secretion, macrophage-induced apoptosis, and tissue factor expression. Responses to solid-phase IgG (but not to IgM) were blocked by neutralizing antibodies to CD16 (FcγRIII), consistent with its known role. Macrophages from mice deficient in macrophage scavenger receptor A (SR-A; CD204) had absent IgM binding and no activation by solid-phase IgM. RNA interference-mediated knockdown of SR-A in human macrophages suppressed activation by solid-phase IgM. IgM binding to SR-A was demonstrated by both co-immunoprecipitation studies and the binding of fluorescently labeled IgM to SR-A-transfected cells. Immunoglobulins on solid-phase particles around macrophages were found in human plaques, increased in ruptured plaques compared with stable ones. These observations indicate that solid-phase IgM and IgG can activate macrophages and destabilize vulnerable plaques. Solid-phase IgM activates macrophages via a novel SR-A pathway.

Evaluation of the impact of phosphate salts on the formation of ionic-liquid-based aqueous biphasic systems

The present study aims at evaluating the capability of phosphate-based salts, whose anions can coexist in water depending on the media pH, to promote aqueous biphasic systems (ABS) formation with 1-butyl-3-methylimidazolium-based ionic liquids, as well as to infer on the influence of the ionic liquid anion in the overall process of liquid–liquid demixing. In this context, novel phase diagrams of ABS composed of several imidazolium-based ionic liquids and three phosphate salts and a mixture of salts (K3PO4, K2HPO4, K2HPO4+KH2PO4, and KH2PO4) were determined by the cloud point titration method at 298K and atmospheric pressure. The corresponding tie-line compositions, tie-line lengths, and pH values of the coexisting phases were also determined. The ionic liquids ability to promote ABS is related with the hydrogen-bond basicity of the composing anion – the lower it is the higher the ability of the ionic fluid to undergo liquid–liquid demixing. Moreover, similar patterns on the ionic liquids sequence were observed with the different phosphate salts. The phosphate anion charge plays a determinant role in the formation of ABS. The two-phase formation aptitude (with a similar ionic liquid) decreases in the rank: K3PO4>K2HPO4>K2HPO4+KH2PO4>KH2PO4. Yet, besides the charge of the phosphate anion, the pH and ionic strength of the aqueous media also influence the phase separation ability.

A novel hybrid nano zerovalent iron initiated oxidation – Biological degradation approach for remediation of recalcitrant waste metalworking fluids

Disposal of operationally exhausted metal working fluids (MWF) through a biological route is an attractive option, since it is effective with relatively low energy demands. However, it is enormously challenging since these fluids are chemically complex, including the addition of toxic biocides which are added specifically to retard bio-deterioration whilst the fluids are operational. Nano-sized elemental iron represents a new generation of environmental remediation technologies. Laboratory scale batch studies were performed to test the degradation ability of a semi-synthetic metalworking fluid (MWF) wastewater (which was found to be resistant to initial bacterial treatment in specifically established bioreactors) by employing a novel hybrid approach. The approach was to combine the synergistic effects of nano zerovalent iron (nZVI) induced oxidation, followed by biodegradation, specifically for the remediation of recalcitrant components of MWF effluent. Addition of nZVI particles to oxygenated wastewater resulted in oxidation of organic contaminants present. Our studies confirmed 78% reduction in chemical oxygen demand (COD) by nZVI oxidation at pH 3.0 and 67% reduction in neutral pH (7.5), and 85% concurrent reduction in toxicity. Importantly, this low toxicity made the nZVI treated effluent more amenable for a second stage biological oxidation step. An overall COD reduction of 95.5% was achieved by the novel combined treatment described, demonstrating that nZVI oxidation can be exploited for enhancing the biodegradability of a recalcitrant wastewater in treatment processes.

Amniotic fluid elicits appetitive responses in human newborns: Fatty acids and appetitive responses

In humans, maternal cues guide newborns to the maternal breast, and transitional cues may be present in maternal-fetal fluids. The aim of the present study was to determine the consistent presence of sensorial cues in three maternal-fetal fluids--amniotic fluid, colostrum, and milk--and test the ability of these cues to produce appetitive responses in newborns. In the analytical study, gas chromatography-mass spectrometry (GC-MS) detected eight fatty acids consistently present in the amniotic fluid, colostrum, and milk from 12 healthy volunteers, but we do not find a mammalian pheromone, identified in another mammalian species (rabbits), in another 30 volunteers. In the behavioral study, we explored the ability of amniotic fluid or its fatty acids to produce appetitive responses in 19 human newborns <24 hr after birth. Exposure to swabs impregnated with amniotic fluid or an artificial fatty acid mixture produced a longer duration of facial reactions that suggested appetitive (sucking) movements compared with respective vehicles (i.e., propylene glycol or centrifuged amniotic fluid with a low fatty acid content verified by GC-MS). We conclude that the fatty acids contained in amniotic fluid may constitute a transitional sensorial cue that guides newborns to the maternal breast.

Cerebrospinal Fluid Levels ofβ-Amyloid 1-42, but Not of Tau, Are Fully Changed Already 5 to 10 Years Before the Onset of Alzheimer Dementia

Early detection of prodromal Alzheimer disease (AD) is important because new disease-modifying therapies are most likely to be effective when initiated during the early stages of disease. To assess the ability of the cerebrospinal fluid (CSF) biomarkers total tau (T-tau), phosphorylated tau (P-tau), and β-amyloid 1-42 (Aβ42) to predict future development of AD dementia within 9.2 years in patients with mild cognitive impairment (MCI) and to compare CSF biomarkers between early and late converters to AD. A clinical study with a median follow-up of 9.2 years (range, 4.1-11.8 years). Memory disorder clinic. Patients A total of 137 patients with MCI who underwent lumbar puncture at baseline. MAIN OUTCOME MEASURE Conversion to AD dementia. During follow-up, 72 patients (53.7%) developed AD and 21 (15.7%) progressed to other forms of dementia. At baseline, CSF Aβ42 levels were reduced and T-tau and P-tau levels were elevated in patients who converted to AD during follow-up compared with nonconverters (P < .001). Baseline CSF Aβ42 levels were equally reduced in patients with MCI who converted to AD within 0 to 5 years (early converters) compared with those who converted between 5 and 10 years (late converters). However, CSF T-tau and P-tau levels were significantly higher in early converters vs late converters. A baseline Aβ42:P-tau ratio predicted the development of AD within 9.2 years with a sensitivity of 88%, specificity of 90%, positive predictive value of 91%, and negative predictive value of 86%. Approximately 90% of patients with MCI and pathologic CSF biomarker levels at baseline develop AD within 9 to 10 years. Levels of Aβ42 are already fully decreased at least 5 to 10 years before conversion to AD dementia, whereas T-tau and P-tau seem to be later markers. These results provide direct support in humans for the hypothesis that altered Aβ metabolism precedes tau-related pathology and neuronal degeneration.

Prevention by rat amniotic fluid of adhesions after laparatomy in a rat model

Background Adhesion formation after abdominal surgery (especially multiple operations) is still a major cause of morbidities such as infertility, pain, bowel obstruction, difficult reoperation and other complications. Our aim was to investigate the ability of rat amniotic fluid to prevent adhesion formation after laparatomy in rats. Methods This experimental trial was conducted in 20 pregnant rats randomly assigned to two groups of 10 animals each. Measurable serosal and intestinal injuries were created with a standard technique. Rats in both groups underwent laparatomy and hysterectomy. Then amniotic fluid was poured into the abdominal cavity of animals in the case group. All animals were operated on 4 weeks after initial surgery to assess adhesions, which were scored by an examiner who was blind to the animals’ group assignment. Results The frequency of severe adhesions was 30% in the control group and 0% in the intervention group. Total adhesion scores were significantly lower in the amniotic fluid treatment group than in the control group ( P = 0.002). Conclusions Rat amniotic fluid can decrease the likelihood of post-operative intraperitoneal adhesion formation.

In vitro effects of etanercept on the development of different T cell subsets in patients with juvenile idiopathic arthritis

Aim In the present study, we assessed the ability of etanercept to influence the in vitro development of different T cell subsets in JIA patients. In particular, we have evaluated the ability of peripheral blood (PB) and synovial fluid (SF) lymphocytes from patients followed in our Unit, to proliferate and produce cytokines in response to polyclonal (antiCD3/antiCD28) stimulation in presence or in absence of etanercept.

Effect of the Molecular Weight of Poly(ethylene glycol) on the Properties of Biocompatible Magnetic Fluids

The effect of the molecular weight of poly(ethylene glycol) (PEG) on the physical properties of water-based magnetic fluids with sodium oleate and PEG stabilization was investigated. The structure as well as magnetic, rheological, and thermal properties of the obtained samples were studied using transmission electron microscopy (TEM), photon cross correlation spectroscopy (PCCS), superconducting quantum interference device (SQUID), and differential scanning calorimetry (DSC) methods. The molecular weight of PEG had a strong effect on the rheological properties while the effect was rather insignificant on the particle size distribution and the self-heating of the studied magnetic fluids. The heating ability of the PEG-stabilized magnetic fluids was determined by calorimetric measurements of the specific absorption rate (SAR). The thickness of the PEG layer was calculated from the experimental data of the temperature rise rates as a function of the magnetic field strength using the Rosensweig theory.

Mathematical simulation of mild brain injury in children heading soccer balls

Heading professional soccer balls can generate mild traumatic brain injury in children. The long-term consequences could include difficulty in solving problems and deficits in memory and language. To assess the impact of a professional adult soccer ball on a child's head, using the finite element method and dynamic effects to predict brain damage. The minimum conditions of an adult game were considered: the ball speed was 6 m/s and the diffuse blow was 345 and 369 Newtons (N), on the forehead and top of the head, respectively. A head was modeled in order to know the stresses, strains and displacements generated by the impacts. The extent of the alteration was determined by comparing the strength of brain tissue, with predictions of computed stresses. The geometric characteristics of the head were transferred from medical images. The input data of the materials of a child's head was obtained from the literature. In the case of heading with the forehead, mathematical simulation showed frontal lobe alterations, with brain stresses between 0.064 and 0.059 N/mm(2). When the heading was with the upper head zone, the brain alterations were in the parietal lobe, with stresses between 0.089 and 0.067 N/mm(2). In the cerebral spinal fluid the pressure was 3.61 to 3.24 N/mm(2). The mathematical simulations reveal evidence of brain alterations caused by a child heading adult soccer balls. The model presented is an economical and quick tool that can help predict brain damage. It demonstrates the ability of the cerebral spinal fluid (CSF) to absorb shock loads.

Traumas cerebrales en niños secundarios a cabeceo de balones en fútbol: Modelo de simulación matemática

Heading professional soccer balls can generate mild traumatic brain injury in children. The long-term consequences could include difficulty in solving problems and deficits in memory and language.To assess the impact of a professional adult soccer ball on a child's head, using the finite element method and dynamic effects to predict brain damage.The minimum conditions of an adult game were considered: the ball speed was 6 m/s and the diffuse blow was 345 and 369 Newtons (N), on the forehead and top of the head, respectively. A head was modeled in order to know the stresses, strains and displacements generated by the impacts. The extent of the alteration was determined by comparing the strength of brain tissue, with predictions of computed stresses. The geometric characteristics of the head were transferred from medical images. The input data of the materials of a child's head was obtained from the literature.In the case of heading with the forehead, mathematical simulation showed frontal lobe alterations, with brain stresses between 0.064 and 0.059 N/mm(2). When the heading was with the upper head zone, the brain alterations were in the parietal lobe, with stresses between 0.089 and 0.067 N/mm(2). In the cerebral spinal fluid the pressure was 3.61 to 3.24 N/mm(2).The mathematical simulations reveal evidence of brain alterations caused by a child heading adult soccer balls. The model presented is an economical and quick tool that can help predict brain damage. It demonstrates the ability of the cerebral spinal fluid (CSF) to absorb shock loads.