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Sample records for brain swelling due

  1. Cardiac arrest due to intracranial hypotension following pseudohypoxic brain swelling induced by negative suction drainage in a cranioplasty patient: a case report

    PubMed Central

    Kim, Su Ryun; Kim, Seon Ju

    2016-01-01

    Pseudohypoxic brain swelling (PHBS) is known to be an uncommon event that may occur during and following an uneventful brain surgery, when negative suction drainage is used. The cerebrospinal fluid loss related to suction drainage can evoke intracranial hypotension that progress to PHBS. The main presentations of PHBS are sudden unexpected circulatory collapses, such as severe bradycardia, hypotension, cardiac arrest, consciousness deterioration and diffuse brain swelling as seen with brain computerized tomography (CT). We present a stuporous 22-year-old patient who underwent cranioplasty under general anesthesia. The entire course of the general anesthesia and operation progressed favorably. However, the time of scalp suture completion, sudden bradycardia and hypotension occurred, followed by cardiac arrest immediately after initiation of subgaleal and epidural suction drainage. After successful resuscitation, the comatose patient was transferred to the neurosurgical intensive care unit and PHBS was confirmed using brain CT. PMID:27274378

  2. Brain swelling and ischaemia in Kenyans with cerebral malaria.

    PubMed Central

    Newton, C R; Peshu, N; Kendall, B; Kirkham, F J; Sowunmi, A; Waruiru, C; Mwangi, I; Murphy, S A; Marsh, K

    1994-01-01

    Computed tomography was performed on 14 unconscious Kenyan children recovering from cerebral malaria (seven of whom had another scan 12-120 days later) to elucidate the cause of intracranial hypertension and neurological sequelae. Brain swelling, defined as a loss of cerebrospinal fluid spaces, was documented in six children, while a further two had conspicuously small ventricles only. There was severe intracranial hypertension in the two children with definite brain swelling in whom intracranial pressure was monitored. There was no evidence of acute hydrocephalus or vasogenic oedema. Four children with brain swelling also had widespread low density areas suggestive of ischaemic damage. The patterns of damage were not uniform but were consistent with a critical reduction in cerebral perfusion pressure (which was documented in the two in whom this was monitored), hypoglycaemia, or status epilepticus. All four had serious neurological sequelae. These data suggest that brain injury in cerebral malaria may be due in part to secondary systemic and intracranial factors as well as to the direct effect of intravascular sequestration. Images PMID:8185359

  3. Today's Approach to Treating Brain Swelling in the Neuro Intensive Care Unit.

    PubMed

    Shah, Shreyansh; Kimberly, W Taylor

    2016-12-01

    Brain swelling is an urgent clinical problem that frequently accompanies ischemic stroke, brain hemorrhage, and traumatic brain injury; it increases morbidity and mortality associated with them. It occurs due to failure of membrane transporters and leakage of the blood-brain barrier (BBB), resulting in combination of cytotoxic, ionic, and vasogenic edema. Currently, decompressive craniectomy and osmotherapy are the mainstays of management, but these therapies do not halt the underlying molecular cascade leading to brain swelling. Recent advances in the molecular underpinnings of cerebral edema have opened up possibilities of newer targeted therapeutic options. Here the authors outline the current approach for rapid diagnosis and intervention to reduce mortality and morbidity associated with brain swelling. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. Swelling

    MedlinePlus

    ... summer months, especially if a person has been standing or walking a lot. General swelling, or massive ... caused by any of the following: Acute glomerulonephritis Burns , including sunburn Chronic kidney disease Heart failure Liver ...

  5. Brain Swelling and Death in Children with Cerebral Malaria

    PubMed Central

    Seydel, Karl B.; Kampondeni, Samuel D.; Valim, Clarissa; Potchen, Michael J.; Milner, Danny A.; Muwalo, Francis W.; Birbeck, Gretchen L.; Bradley, William G.; Fox, Lindsay L.; Glover, Simon J.; Hammond, Colleen A.; Heyderman, Robert S.; Chilingulo, Cowles A.; Molyneux, Malcolm E.; Taylor, Terrie E.

    2015-01-01

    BACKGROUND Case fatality rates among African children with cerebral malaria remain in the range of 15 to 25%. The key pathogenetic processes and causes of death are unknown, but a combination of clinical observations and pathological findings suggests that increased brain volume leading to raised intracranial pressure may play a role. Magnetic resonance imaging (MRI) became available in Malawi in 2009, and we used it to investigate the role of brain swelling in the pathogenesis of fatal cerebral malaria in African children. METHODS We enrolled children who met a stringent definition of cerebral malaria (one that included the presence of retinopathy), characterized them in detail clinically, and obtained MRI scans on admission and daily thereafter while coma persisted. RESULTS Of 348 children admitted with cerebral malaria (as defined by the World Health Organization), 168 met the inclusion criteria, underwent all investigations, and were included in the analysis. A total of 25 children (15%) died, 21 of whom (84%) had evidence of severe brain swelling on MRI at admission. In contrast, evidence of severe brain swelling was seen on MRI in 39 of 143 survivors (27%). Serial MRI scans showed evidence of decreasing brain volume in the survivors who had had brain swelling initially. CONCLUSIONS Increased brain volume was seen in children who died from cerebral malaria but was uncommon in those who did not die from the disease, a finding that suggests that raised intracranial pressure may contribute to a fatal outcome. The natural history indicates that increased intracranial pressure is transient in survivors. (Funded by the National Institutes of Health and Wellcome Trust U.K.) PMID:25785970

  6. Brain swelling and death in children with cerebral malaria.

    PubMed

    Seydel, Karl B; Kampondeni, Samuel D; Valim, Clarissa; Potchen, Michael J; Milner, Danny A; Muwalo, Francis W; Birbeck, Gretchen L; Bradley, William G; Fox, Lindsay L; Glover, Simon J; Hammond, Colleen A; Heyderman, Robert S; Chilingulo, Cowles A; Molyneux, Malcolm E; Taylor, Terrie E

    2015-03-19

    Case fatality rates among African children with cerebral malaria remain in the range of 15 to 25%. The key pathogenetic processes and causes of death are unknown, but a combination of clinical observations and pathological findings suggests that increased brain volume leading to raised intracranial pressure may play a role. Magnetic resonance imaging (MRI) became available in Malawi in 2009, and we used it to investigate the role of brain swelling in the pathogenesis of fatal cerebral malaria in African children. We enrolled children who met a stringent definition of cerebral malaria (one that included the presence of retinopathy), characterized them in detail clinically, and obtained MRI scans on admission and daily thereafter while coma persisted. Of 348 children admitted with cerebral malaria (as defined by the World Health Organization), 168 met the inclusion criteria, underwent all investigations, and were included in the analysis. A total of 25 children (15%) died, 21 of whom (84%) had evidence of severe brain swelling on MRI at admission. In contrast, evidence of severe brain swelling was seen on MRI in 39 of 143 survivors (27%). Serial MRI scans showed evidence of decreasing brain volume in the survivors who had had brain swelling initially. Increased brain volume was seen in children who died from cerebral malaria but was uncommon in those who did not die from the disease, a finding that suggests that raised intracranial pressure may contribute to a fatal outcome. The natural history indicates that increased intracranial pressure is transient in survivors. (Funded by the National Institutes of Health and Wellcome Trust U.K.).

  7. Apnoea and brain swelling in non-accidental head injury

    PubMed Central

    Kemp, A; Stoodley, N; Cobley, C; Coles, L; Kemp, K; Geddes, J

    2003-01-01

    Aims: (1) To identify whether infants and young children admitted to hospital with subdural haematomas (SDH) secondary to non-accidental head injury (NAHI), suffer from apnoea leading to radiological evidence of hypoxic ischaemic brain damage, and whether this is related to a poor prognosis; and (2) to determine what degree of trauma is associated with NAHI. Methods: Retrospective case series (1992–98) with case control analysis of 65 children under 2 years old, with an SDH secondary to NAHI. Outcome measures were presenting symptoms, associated injuries and apnoea at presentation, brain swelling or hypoxic ischaemic changes on neuroimaging, and clinical outcome (KOSCHI). Results: Twenty two children had a history of apnoea at presentation to hospital. Apnoea was significantly associated with hypoxic ischaemic brain damage. Severe symptoms at presentation, apnoea, and diffuse brain swelling/hypoxic ischaemic damage were significantly associated with a poor prognosis. Eighty five per cent of cases had associated injuries consistent with a diagnosis of non-accidental injury. Conclusions: Coma at presentation, apnoea, and diffuse brain swelling or hypoxic ischaemia all predict a poor outcome in an infant who has suffered from SDH after NAHI. There is evidence of associated violence in the majority of infants with NAHI. At this point in time we do not know the minimum forces necessary to cause NAHI. It is clear however that it is never acceptable to shake a baby. PMID:12765909

  8. Hydrogels for engineering: normalization of swelling due to arbitrary stimulus

    NASA Astrophysics Data System (ADS)

    Ehrenhofer, Adrian; Wallmersperger, Thomas

    2017-04-01

    In engineering, materials are chosen from databases: Engineers orient on specific parameters such as Young's modulus, yield stress or thermal expansion coefficients for a desired application. For hydrogels, the choice of materials is rather tedious since no generalized material parameters are currently available to quantify the swelling behavior. The normalization of swelling, which we present in the current work, allows an easy comparison of different hydrogel materials. Thus, for a specific application like a sensor or an actuator, an adequate material can be chosen. In the current work, we present the process of normalization and provide a course of action for the data analysis. Special challenges for hydrogels like hysteresis, conditional multi-sensitivity and anisotropic swelling are addressed. Then, the Temperature Expansion Model is shortly described and applied. Using the derived normalized swelling curves, a nonlinear expansion coefficient ß(F) is derived. The derived material behavior is used in an analytical model to predict the bending behavior of a beam made of thermo-responsive hydrogel material under an anisotropic temperature load. A bending behavior of the beam can be observed and the impact of other geometry and material parameters can be investigated. To overcome the limitations of the one-dimensional beam theory, the material behavior and geometry can be implemented in Finite Element analysis tools. Thus, novel applications for hydrogels in various fields can be envisioned, designed and tested. This can lead to a wider use of smart materials in sensor or actuator devices even by engineers without chemical background.

  9. Sarcoidosis detected due to tattoo swellings in an Indian female.

    PubMed

    Ghorpade, Ashok

    2015-01-01

    A female patient presented with asymptomatic swellings in old blue-black tattoo marks of her forearms. On careful skin examination, few raised erythematous, circular plaques were also found on the non-tattooed skin on her back, about which she was unaware. The diagnosis of cutaneous and systemic sarcoidosis was confirmed after classical histopathological findings from skin lesions from her non tattooed back and from papulonodular tattooed lesions, ruling out other causes of granulomas and supported by a negative Mantoux test, raised serum angiotensin converting enzyme level, high resolution computed tomography thorax, etc. She responded well to oral steroid therapy. The importance of a careful skin examination, easy access provided by skin lesions in suspected cases of cutaneous/systemic sarcoidosis, the value of sudden tattoo changes in the diagnosis here and the possible contribution of tattoos toward the causation of cutaneous and/or systemic sarcoidosis are highlighted.

  10. Optical scatter imaging of cellular and mitochondrial swelling in brain tissue models of stroke

    NASA Astrophysics Data System (ADS)

    Johnson, Lee James

    2001-08-01

    The severity of brain edema resulting from a stroke can determine a patient's survival and the extent of their recovery. Cellular swelling is the microscopic source of a significant part of brain edema. Mitochondrial swelling also appears to be a determining event in the death or survival of the cells that are injured during a stroke. Therapies for reducing brain edema are not effective in many cases and current treatments of stroke do not address mitochondrial swelling at all. This dissertation is motivated by the lack of a complete understanding of cellular swelling resulting from stroke and the lack of a good method to begin to study mitochondrial swelling resulting from stroke in living brain tissue. In this dissertation, a novel method of detecting mitochondrial and cellular swelling in living hippocampal slices is developed and validated. The system is used to obtain spatial and temporal information about cellular and mitochondrial swelling resulting from various models of stroke. The effect of changes in water content on light scatter and absorption are examined in two models of brain edema. The results of this study demonstrate that optical techniques can be used to detect changes in water content. Mie scatter theory, the theoretical basis of the dual- angle scatter ratio imaging system, is presented. Computer simulations based on Mie scatter theory are used to determine the optimal angles for imaging. A detailed account of the early systems is presented to explain the motivations for the system design, especially polarization, wavelength and light path. Mitochondrial sized latex particles are used to determine the system response to changes in scattering particle size and concentration. The dual-angle scatter ratio imaging system is used to distinguish between osmotic and excitotoxic models of stroke injury. Such distinction cannot be achieved using the current techniques to study cellular swelling in hippocampal slices. The change in the scatter ratio is

  11. Relationship between oxidative stress and brain swelling in goldfish (Carassius auratus) exposed to high environmental ammonia.

    PubMed

    Lisser, David F J; Lister, Zachary M; Pham-Ho, Phillip Q H; Scott, Graham R; Wilkie, Michael P

    2017-01-01

    Buildups of ammonia can cause potentially fatal brain swelling in mammals, but such swelling is reversible in the anoxia- and ammonia-tolerant goldfish (Carassius auratus). We investigated brain swelling and its possible relationship to oxidative stress in the brain and liver of goldfish acutely exposed to high external ammonia (HEA; 5 mmol/l NH4Cl) at two different acclimation temperatures (14°C, 4°C). Exposure to HEA at 14°C for 72h resulted in increased internal ammonia and glutamine concentrations in the brain, and it caused cellular oxidative damage in the brain and liver. However, oxidative damage was most pronounced in brain, in which there was a twofold increase in thiobarbituric acid-reactive substances, a threefold increase in protein carbonylation, and a 20% increase in water volume (indicative of brain swelling). Increased activities of catalase, glutathione peroxidase, and glutathione reductase in the brain suggested that goldfish upregulate their antioxidant capacity to partially offset oxidative stress during hyperammonemia at 14°C. Notably, acclimation to colder (4°C) water completely attenuated the oxidative stress response to HEA in both tissues, and there was no change in brain water volume despite similar increases in internal ammonia. We suggest that ammonia-induced oxidative stress may be responsible for the swelling of goldfish brain during HEA, but further studies are needed to establish a mechanistic link between reactive oxygen species production and brain swelling. Nevertheless, a high capacity to withstand oxidative stress in response to variations in internal ammonia likely explains why goldfish are more resilient to this stressor than most other vertebrates. Copyright © 2017 the American Physiological Society.

  12. Sulfonylurea receptor 1 contributes to the astrocyte swelling and brain edema in acute liver failure.

    PubMed

    Jayakumar, A R; Valdes, V; Tong, X Y; Shamaladevi, N; Gonzalez, W; Norenberg, M D

    2014-02-01

    Astrocyte swelling (cytotoxic brain edema) is the major neurological complication of acute liver failure (ALF), a condition in which ammonia has been strongly implicated in its etiology. Ion channels and transporters are known to be involved in cell volume regulation, and a disturbance in these systems may result in cell swelling. One ion channel known to contribute to astrocyte swelling/brain edema in other neurological disorders is the ATP-dependent, nonselective cation (NCCa-ATP) channel. We therefore examined its potential role in the astrocyte swelling/brain edema associated with ALF. Cultured astrocytes treated with 5 mM ammonia showed a threefold increase in the sulfonylurea receptor type 1 (SUR1) protein expression, a marker of NCCa-ATP channel activity. Blocking SUR1 with glibenclamide significantly reduced the ammonia-induced cell swelling in cultured astrocytes. Additionally, overexpression of SUR1 in ammonia-treated cultured astrocytes was significantly reduced by cotreatment of cells with BAY 11-7082, an inhibitor of NF-κB, indicating the involvement of an NF-κB-mediated SUR1 upregulation in the mechanism of ammonia-induced astrocyte swelling. Brain SUR1 mRNA level was also found to be increased in the thioacetamide (TAA) rat model of ALF. Additionally, we found a significant increase in SUR1 protein expression in rat brain cortical astrocytes in TAA-treated rats. Treatment with glibenclamide significantly reduced the brain edema in this model of ALF. These findings strongly suggest the involvement of NCCa-ATP channel in the astrocyte swelling/brain edema in ALF and that targeting this channel may represent a useful approach for the treatment of the brain edema associated with ALF.

  13. Brain swelling and mannitol therapy in adult cerebral malaria: a randomized trial.

    PubMed

    Mohanty, Sanjib; Mishra, Saroj Kanti; Patnaik, Rajyabardhan; Dutt, Anil Kumar; Pradhan, Sudhir; Das, Bhabanisankar; Patnaik, Jayakrushna; Mohanty, Akshaya Kumar; Lee, Sue J; Dondorp, Arjen M

    2011-08-01

    Coma is a frequent presentation of severe malaria in adults and an important cause of death. The role of cerebral swelling in its pathogenesis, and the possible benefit of intravenous mannitol therapy to treat this, is uncertain. A computed tomographic (CT) scan of the cerebrum and lumbar puncture with measurement of cerebrospinal fluid (CSF) pressure were performed on admission for 126 consecutive adult Indian patients with cerebral malaria. Patients with brain swelling on CT scan were randomized to adjunctive treatment with intravenous mannitol (1.5 g/kg followed by 0.5 g/kg every 8 hours; n = 30) or no adjunctive therapy (n = 31). On CT scan 80 (63%) of 126 patients had cerebral swelling, of whom 36 (29%) had moderate or severe swelling. Extent of brain swelling was not related to coma depth or mortality. CSF pressures were elevated (≥200 mm H(2)O) in 43 (36%) of 120 patients and correlated with CT scan findings (P for trend = .001). Mortality with mannitol therapy was 9 (30%) of 30 versus 4 (13%) of 31 without adjunctive therapy (hazard ratio, 2.4 [95% confidence interval, 0.8-7.3]; P = .11). Median coma recovery time was 90 hours (range, 22-380 hours) with mannitol versus 32 hours (range, 5-168 hours) without (P = .02). Brain swelling on CT scan is a common finding in adult patients with cerebral malaria but is not related to coma depth or survival. Mannitol therapy as adjunctive treatment for brain swelling in adult cerebral malaria prolongs coma duration and may be harmful.

  14. Thermodynamic model for swelling of unconfined coal due to adsorption of mixed gases

    NASA Astrophysics Data System (ADS)

    Liu, Jinfeng; Peach, Colin; Spiers, Christopher

    2013-04-01

    Permeability evolution in coal reservoirs during CO2-Enhanced Coalbed Methane (ECBM) production is strongly influenced by swelling/shrinkage effects related to sorption and desorption of both CO2 and CH4. Other gases, such as N2, may perhaps also be used in ECBM operations. Much work has been done on the sorption/swelling response of coal to the pure gases. However, there is a clear need for an improved understanding of swelling behaviour of coal matrix material as a result of mixed gas adsorption. We therefore constructed a thermodynamic model for swelling of unconfined coal due to mixed gases adsorption, considering the equilibrium state (swelling strain eadseq), focusing initially on a binary gas mixture. Following Hol et al (2012, IJCG, 93, 1-15), we started with the following basic assumptions: a) nanoporous coal matrix material only allows diffusion and adsorption, b) the matrix hosts nsi(i=α, β) localised adsorption sites for the two gas components α and β, c) the material is homogeneous in structure and composition but may be anisotropic in properties as appropriate for natural coal, d) adsorption is allowed to proceed until equilibrium is reached, at which point the chemical potential of the adsorbed component i is equal to the potential of the free component phase i, and e) the volume change (strain) associated with adsorption of one molecule of component i is insensitive to the adsorbed concentration of either component. Three models were derived corresponding to three possible interactions: 1) Isolated adsorption sites model. This assumes that each component has its own specific adsorption sites. Adsorption of α and β accordingly leads to independent swelling responses that sum to give total volumetric strain. 2) Shared adsorption sites model. This postulates that both gases have full access to all adsorption sites (nsα = nsβ = ns). This model is thermodynamically equivalent to the Extended Langmuir model. If the free fluids behave as ideal

  15. [The effect of fenibut on the ultrastructure of the brain mitochondria in traumatic edema and swelling].

    PubMed

    Novikov, V E; Naperstnikov, V V

    1994-01-01

    Rat experiments using electron microscopy have established that profound destructive changes occur in the mitochondria in the intra- and perifocal traumatic area in dynamics of traumatic edema-swelling. With phenibut, 50 mg/kg, there is an increase in the number of mitochondria in the brain tissue of the perifocal area, their destructive changes are less pronounced. It is assumed that the positive effect of phenibut on brain bioenergetic processes in the posttraumatic period is associated with the changes.

  16. Ammonia-induced brain swelling and neurotoxicity in an organotypic slice model

    PubMed Central

    Back, Adam; Tupper, Kelsey Y.; Bai, Tao; Chiranand, Paulpoj; Goldenberg, Fernando D.; Frank, Jeffrey I.; Brorson, James R.

    2013-01-01

    Objectives Acute liver failure produces cerebral dysfunction and edema, mediated in part by elevated ammonia concentrations, often leading to coma and death. The pathophysiology of cerebral edema in acute liver failure is incompletely understood. In vitro models of the cerebral effects of acute liver failure have predominately consisted of dissociated astrocyte cultures or acute brain slices. We describe a stable long-term culture model incorporating both neural and glial elements in a three-dimensional tissue structure offering significant advantages to the study of astrocytic-neuronal interactions in the pathophysiology of cerebral edema and dysfunction in acute liver failure. Methods We utilized chronic organotypic slice cultures from mouse forebrain, applying ammonium acetate in iso-osmolar fashion for 72 hours. Imaging of slice thickness to assess for tissue swelling was accomplished in living slices with optical coherence tomography, and confocal microscopy of fluorescence immunochemical and histochemical staining served to assess astrocyte and neuronal numbers, morphology, and volume in the fixed brain slices. Results Ammonia exposure at 1–10 mM produced swelling of immunochemically-identified astrocytes, and at 10 mM resulted in macroscopic tissue swelling, with slice thickness increasing by about 30%. Astrocytes were unchanged in number. In contrast, 10 mM ammonia treatment severely disrupted neuronal morphology and reduced neuronal survival at 72 hours by one-half. Discussion Elevated ammonia produces astrocytic swelling, tissue swelling, and neuronal toxicity in cerebral tissues. Ammonia-treated organotypic brain slice cultures provide an in vitro model of cerebral effects of conditions relevant to acute liver failure, applicable to pathophysiological investigations. PMID:22196764

  17. HEME OXYGENASE 2 DEFICIENCY INCREASES BRAIN SWELLING AND INFLAMMATION AFTER INTRACEREBRAL HEMORRHAGE

    PubMed Central

    WANG, J.; DORÉ, S.

    2015-01-01

    Intracerebral hemorrhage (ICH) remains a major medical problem and currently has no effective treatment. Hemorrhaged blood is highly toxic to the brain, and catabolism of the pro-oxidant heme, mainly released from hemoglobin, is critical for the resolution of hematoma after ICH. The degradation of the pro-oxidant heme is controlled by heme oxygenase (HO). We have previously reported a neuroprotective role for HO2 in early brain injury after ICH; however, in vivo data that specifically address the role of HO2 in brain edema and neuroinflammation after ICH are absent. Here, we tested the hypothesis that HO2 deletion would exacerbate ICH-induced brain edema, neuroinflammation, and oxidative damage. We subjected wild-type (WT) and HO2 knockout (−/−) mice to the collagenase-induced ICH model. Interestingly, HO2−/− mice had enhanced brain swelling and neuronal death, although HO2 deletion did not increase collagenase-induced bleeding; the exacerbation of brain injury in HO2−/− mice was also associated with increases in neutrophil infiltration, microglial/macrophage and astrocyte activation, DNA damage, peroxynitrite production, and cytochrome c immunoreactivity. In addition, we found that hemispheric enlargement was more sensitive than brain water content in the detection of subtle changes in brain edema formation in this model. Combined, these novel findings extend our previous observations and demonstrate that HO2 deficiency increases brain swelling, neuroinflammation, and oxidative damage. The results provide additional evidence that HO2 plays a critical protective role against ICH-induced early brain injury. PMID:18674596

  18. Mathematical model of the effect of ischemia-reperfusion on brain capillary collapse and tissue swelling.

    PubMed

    Mohamed Mokhtarudin, M J; Payne, S J

    2015-05-01

    Restoration of an adequate cerebral blood supply after an ischemic attack is a primary clinical goal. However, the blood-brain barrier may break down after a prolonged ischemia causing the fluid in the blood plasma to filtrate and accumulate into the cerebral tissue interstitial space. Accumulation of this filtration fluid causes the cerebral tissue to swell, a condition known as vasogenic oedema. Tissue swelling causes the cerebral microvessels to be compressed, which may further obstruct the blood flow into the tissue, thus leading to the no-reflow phenomenon or a secondary ischemic stroke. The actual mechanism of this however is still not fully understood. A new model is developed here to study the effect of reperfusion on the formation of vasogenic oedema and cerebral microvessel collapse. The formation of vasogenic oedema is modelled using the capillary filtration equation while vessel collapse is modelled using the tube law of microvessel. Tissue swelling is quantified in terms of displacement, which is modelled using poroelastic theory. The results show that there is an increase in tissue displacement and interstitial pressure after reperfusion. In addition, the results also show that vessel collapse can occur at high value of reperfusion pressure, low blood osmotic pressure, high cerebral capillary permeability and low cerebral capillary stiffness. This model provides insight on the formation of ischemia-reperfusion injury by tissue swelling and vessel collapse. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Quantitative analysis of brain edema and swelling on early postmortem computed tomography: comparison with antemortem computed tomography.

    PubMed

    Takahashi, Naoya; Satou, Chihiro; Higuchi, Takeshi; Shiotani, Motoi; Maeda, Haruo; Hirose, Yasuo

    2010-06-01

    The aim of this study was quantitatively to analyze brain edema and swelling due to early postmortem changes using computed tomography (CT) scans of the head. Review board approval was obtained, and informed consent was waived. A total of 41 patients who underwent head CT before and shortly after death were enrolled. Hounsfield units (HUs) of gray matter (GM) and white matter (WM) were measured at the levels of the basal ganglia, centrum semiovale, and high convexity area on both antemortem and postmortem CT. The length of the minor axis of the third ventricle at the level of the basal ganglia and the width of the central sulcus at the level of high convexity were measured. At each level tested, the HUs of GM and the GM/WM ratios on postmortem CT were significantly lower than those on antemortem CT (P < 0.001). HUs of WM on postmortem CT were slightly higher than those on antemortem CT but without significant difference (P > 0.1). Postmortem CT showed subtle loss of distinction between GM and WM. The size of the third ventricle and the width of the central sulcus did not vary before and after death (P > 0.1). Early postmortem CT shows mild brain edema but does not show brain swelling.

  20. Delayed Brain Edema and Swelling following Craniectomy for Evacuation of an Epidural Abscess that Improved by Cranioplasty: Case Report.

    PubMed

    Sugii, Narushi; Matsuda, Masahide; Sekine, Tomokazu; Matsumura, Hideaki; Yamamoto, Tetsuya; Matsumura, Akira

    2017-07-01

    We report a unique case of delayed brain swelling following craniectomy that improved rapidly after cranioplasty, and discuss the potential mechanism underlying this delayed and reversible brain swelling. A 22-year-old woman developed surgical site infection after removal of a convexity meningioma. Magnetic resonance imaging revealed an epidural abscess around the surgical site. Subsequently, the abscess was evacuated, and the bone flap was removed. Later, brain edema around the skull defect emerged and progressed gradually, despite resolution of the infection. The edematous brain developed focal swelling outward through the bone defect without ventricle dilatation. Because we suspected that the edema and swelling were caused by the state of the bone defect, we performed a cranioplasty 10 weeks after the bone flap removal, and brain edema improved rapidly. We hypothesized that the brain edema was initially caused by surgical stress and inflammation, followed by compression of cortical veins between the dural edge and brain tissue, leading to disruption of venous return and exacerbation of brain edema. When delayed focal brain edema and external swelling progress gradually after bone flap removal, after excluding other pathological conditions, cranioplasty should be considered to improve cortical venous congestion caused by postsurgical adhesion.

  1. Dimensional errors in LIGA-produced metal structures due to thermal expansion and swelling of PMMA.

    SciTech Connect

    Kistler, Bruce L.; Dryden, Andrew S.; Crowell, Jeffrey A.W.; Griffiths, Stewart K.

    2004-04-01

    Numerical methods are used to examine dimensional errors in metal structures microfabricated by the LIGA process. These errors result from elastic displacements of the PMMA mold during electrodeposition and arise from thermal expansion of the PMMA when electroforming is performed at elevated temperatures and from PMMA swelling due to absorption of water from aqueous electrolytes. Both numerical solutions and simple analytical approximations describing PMMA displacements for idealized linear and axisymmetric geometries are presented and discussed. We find that such displacements result in tapered metal structures having sidewall slopes up to 14 {micro}m per millimeter of height for linear structures bounded by large areas of PMMA. Tapers for curved structures are of similar magnitude, but these structures are additionally skewed from the vertical. Potential remedies for reducing dimensional errors are also discussed. Here we find that auxiliary moat-like features patterned into the PMMA surrounding mold cavities can reduce taper by an order of magnitude or more. Such moats dramatically reduce tapers for all structures, but increase skew for curved structures when the radius of curvature is comparable to the structure height.

  2. Swelling-induced changes in coal microstructure due to supercritical CO2 injection

    NASA Astrophysics Data System (ADS)

    Zhang, Yihuai; Lebedev, Maxim; Sarmadivaleh, Mohammad; Barifcani, Ahmed; Iglauer, Stefan

    2016-09-01

    Enhanced coalbed methane recovery and CO2 geostorage in coal seams are severely limited by permeability decrease caused by CO2 injection and associated coal matrix swelling. Typically, it is assumed that matrix swelling leads to coal cleat closure, and as a consequence, permeability is reduced. However, this assumption has not yet been directly observed. Using a novel in situ reservoir condition X-ray microcomputed tomography flooding apparatus, for the first time we observed such microcleat closure induced by supercritical CO2 flooding in situ. Furthermore, fracturing of the mineral phase (embedded in the coal) was observed; this fracturing was induced by the internal swelling stress. We conclude that coal permeability is drastically reduced by cleat closure, which again is caused by coal matrix swelling, which again is caused by flooding with supercritical CO2.

  3. Penis swelling due to foreign body reaction after injection of silicone.

    PubMed

    Plaza, Tobias; Lautenschlager, Stephan

    2010-09-01

    A 19-year-old man presented with phimosis and painful swelling of the penis four weeks after augmentation with silicone in Thailand. Histology revealed a foreign body reaction to silicone. Infectious causes were ruled out. Granulomatous foreign body reactions to silicone are common, but there are few case reports on reactions following silicone injection for penis enlargement. Foreign body reactions should be included in the differential diagnosis of penis swelling.

  4. Variations in diameter measurements of Robusta Eucalyptus due to swelling and shrinking of bark

    Treesearch

    Robert E. Burgan

    1971-01-01

    Trunk diameters of Eucalyptus robusta trees shrink and swell as bark moisture content changes. Diameter variations from this cause as measured on six trees with a dial-gage dendrometer were less than 1 percent of trunk diameter. To compare this variation with the variation in d.b.h. measurements that can result from personal techiques of using a...

  5. Reversible brain swelling in crucian carp (Carassius carassius) and goldfish (Carassius auratus) in response to high external ammonia and anoxia.

    PubMed

    Wilkie, Michael P; Stecyk, Jonathan A W; Couturier, Christine S; Sidhu, Sanya; Sandvik, Guro K; Nilsson, Göran E

    2015-06-01

    Increased internal ammonia (hyperammonemia) and ischemic/anoxic insults are known to result in a cascade of deleterious events that can culminate in potentially fatal brain swelling in mammals. It is less clear, however, if the brains of fishes respond to ammonia in a similar manner. The present study demonstrated that the crucian carp (Carassius carassius) was not only able to endure high environmental ammonia exposure (HEA; 2 to 22 mmol L(-1)) but that they experienced 30% increases in brain water content at the highest ammonia concentrations. This swelling was accompanied by 4-fold increases in plasma total ammonia (TAmm) concentration, but both plasma TAmm and brain water content were restored to pre-exposure levels following depuration in ammonia-free water. The closely related, ammonia-tolerant goldfish (Carassius auratus) responded similarly to HEA (up to 3.6 mmol L(-1)), which was accompanied by 4-fold increases in brain glutamine. Subsequent administration of the glutamine synthetase inhibitor, methionine sulfoximine (MSO), reduced brain glutamine accumulation by 80% during HEA. However, MSO failed to prevent ammonia-induced increases in brain water content suggesting that glutamine may not be directly involved in initiating ammonia-induced brain swelling in fishes. Although the mechanisms of brain swelling are likely different, exposure to anoxia for 96 h caused similar, but lesser (10%) increases in brain water content in crucian carp. We conclude that brain swelling in some fishes may be a common response to increased internal ammonia or lower oxygen but further research is needed to deduce the underlying mechanisms behind such responses. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Laboratory Study of Crack Development and Crack Interaction in Concrete Blocks due to Swelling of Cracking Agent

    NASA Astrophysics Data System (ADS)

    Frühwirt, Thomas; Plößer, Arne; Konietzky, Heinz

    2015-04-01

    The main focus of this work was to investigate temporary and spatial features of crack development in concrete blocks due to the action of a swelling agent. A commercial available cement-based mortar which shows heavily swelling behaviour when hydrating is used to provide inside pressure in boreholes in conrete blocks and hence serves as cracking agent. As no data for the swelling behaviour of the cracking agent were available the maximum axial swelling stress and axial free swelling strain were determined experimentally. In a first series of tests on concrete blocks the influence of an external mechanical, unidirectional stress on the development-time and orientation of cracks has been investigated for a range of loading levels. The stress state in the blocks prepared with a single borehole was determined by a superposition of internal stresses caused by swelling pressure and external mechanical loading. For a second series of tests prismatic blocks with two boreholes where prepared. This test setup allowed to realize different orientation of boreholes with respect to the uniaxial loading direction. Complementary tests were done using the cracking agent in both, only one or none of the boreholes. Different modes of crack interaction and influence of filled or unfilled boreholes have been observed. Features of crack development showed significant sensitivity to external loading. Starting even at very low load levels crack orientation was primarely determined by the direction of the external load. Temporal change in crack development due to the different load levels was insignificant and no consistent conclusion could be drawn. Crack interaction phenomena only were observed with two boreholes orientated primarely in direction of the external loading. Even in these cases crack orientation was mainly determined by the external stress field and only locally influenced by other cracks or the unfilled borehole. The work provides us with an extensive catalogue of

  7. “Caught by the Eye of Sound” – Epigastric Swelling due to Xiphisternal Tuberculosis

    PubMed Central

    Grover, Shabnam Bhandari; Arora, Sumit; Kumar, Amit; Grover, Hemal; Katyan, Amit; Nair, Deepthi Mohan

    2017-01-01

    Summary Background Common causes of an epigastric mass include hepatomegaly, pancreatic pseudocyst and epigastric hernia, less common causes being carcinoma of the stomach or pancreas, whereas diseases of the sternum presenting as an epigastric swelling is extremely uncommon. We report a case of tubercular infection of the sternum located in the xiphoid process resulting in its presentation as an epigastric swelling. Case Report A 30-year-old immunocompetent woman with complaints of an epigastric swelling and undocumented pyrexia for four months was referred for sonographic evaluation with a clinical suspicion of an incompletely treated liver abscess. The patient was examined with ultrasound, sternal radiographs, CT and MRI. Ultrasound revealed a heterogeneous epigastric collection with linear echogenic components suggestive of bone fragments. These appearances suggested chronic infective osteomyelitis of the xiphoid process of the sternum. Lateral chest radiograph demonstrated lytic destruction of the xiphisternum. Tubercular etiology was considered and further evaluation with Multidetector Computed tomography (MDCT) and Magnetic Resonance Imaging (MRI) demonstrated erosive osteomyelitis of the xiphoid process with enhancing inflammation and collection in the adjoining soft tissue. Ultrasound-guided aspiration, PCR and Amplified Mycobacterium tuberculosis DNA test confirmed tubercular infection. Conclusions We report a new case of osteo-articular tuberculosis localized to the xiphisternum, a rare clinical entity with an extremely unusual clinical presentation as an epigastric mass. The role of ultrasound in primary diagnosis and as an interventional diagnostic modality for guided aspiration is highlighted. PMID:28217237

  8. Simulated diabetic ketoacidosis therapy in vitro elicits brain cell swelling via sodium-hydrogen exchange and anion transport.

    PubMed

    Rose, Keeley L; Watson, Andrew J; Drysdale, Thomas A; Cepinskas, Gediminas; Chan, Melissa; Rupar, C Anthony; Fraser, Douglas D

    2015-08-15

    A common complication of type 1 diabetes mellitus is diabetic ketoacidosis (DKA), a state of severe insulin deficiency. A potentially harmful consequence of DKA therapy in children is cerebral edema (DKA-CE); however, the mechanisms of therapy-induced DKA-CE are unknown. Our aims were to identify the DKA treatment factors and membrane mechanisms that might contribute specifically to brain cell swelling. To this end, DKA was induced in juvenile mice with the administration of the pancreatic toxins streptozocin and alloxan. Brain slices were prepared and exposed to DKA-like conditions in vitro. Cell volume changes were imaged in response to simulated DKA therapy. Our experiments showed that cell swelling was elicited with isolated DKA treatment components, including alkalinization, insulin/alkalinization, and rapid reductions in osmolality. Methyl-isobutyl-amiloride, a nonselective inhibitor of sodium-hydrogen exchangers (NHEs), reduced cell swelling in brain slices elicited with simulated DKA therapy (in vitro) and decreased brain water content in juvenile DKA mice administered insulin and rehydration therapy (in vivo). Specific pharmacological inhibition of the NHE1 isoform with cariporide also inhibited cell swelling, but only in the presence of the anion transport (AT) inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid. DKA did not alter brain NHE1 isoform expression, suggesting that the cell swelling attributed to the NHE1 was activity dependent. In conclusion, our data raise the possibility that brain cell swelling can be elicited by DKA treatment factors and that it is mediated by NHEs and/or coactivation of NHE1 and AT.

  9. Testicular Swelling Due to Lymphatic Filariasis after Brief Travel to Haiti

    PubMed Central

    Marcos, Luis A.; Shapley, Nathan P.; Eberhard, Mark; Epstein, Jonathan I.; Fox, LeAnne M.; Magill, Alan; Nutman, Thomas B.

    2014-01-01

    After 6 months of a trip to Haiti, a 25-year-old healthy man presented with a 6-week history of a very slow progressive intermittent bilateral testicular pain and swelling. The biopsies in both testicles revealed the presence of a dead filarial parasite. Polymerase chain reaction products of the DNA from the biopsy were shown to have a 100% identity to Wuchereria bancrofti. Despite being uncommon in travelers, this presentation of W. bancrofti highlights the possibility of acquiring W. bancrofti during short-term trips to highly endemic regions of the world (i.e., Haiti). PMID:24865674

  10. Head and neck swelling due to a circumferential cicatricial scar in a dog.

    PubMed

    Westermeyer, Hans D; Tobias, Karen M; Reel, Danielle R

    2009-01-01

    A 4-year-old, castrated male, mixed-breed dog was evaluated because of progressive head swelling, exercise intolerance, and increasing respiratory effort of 1 month's duration. Physical examination and radiographs revealed severe edema of the head and face that was cranial to a circumferential, midcervical constriction caused by scarring related to previous removal of a foreign body. Surgical en bloc resection of the cicatricial tissue was performed, and clinical signs resolved completely after 2 months. Histopathology showed ongoing inflammation and hairs within a fibrous band. This case emphasizes that incomplete wound debridement may lead to excessive fibrous tissue proliferation and that thorough wound examination and debridement should be performed after removing circumferential cervical foreign bodies to ensure complete healing.

  11. Role of Cerebral Endothelial Cells in the Astrocyte Swelling and Brain Edema Associated with Acute Hepatic Encephalopathy

    PubMed Central

    Jayakumar, A.R.; Tong, X.Y.; Ospel, J.; Norenberg, M.D.

    2012-01-01

    Brain edema is an important complication of acute hepatic encephalopathy (AHE), and astrocyte swelling is largely responsible for its development. Elevated blood and brain ammonia levels have been considered as major etiological factors in this edema. In addition to ammonia, recent studies have suggested that systemic infection, inflammation (and associated cytokines), as well as endotoxin (lipopolysaccharide, LPS) are also involved in AHE-associated brain edema. As endothelial cells (ECs) are the first resident brain cells exposed to blood-borne “noxious agents” (i.e., ammonia, cytokines, LPS) that are present in AHE, these cells may be in a critical position to react to these agents and trigger a process resulting in astrocyte swelling/brain edema. We therefore examined the effect of conditioned media (CM) from ammonia, LPS and cytokine-treated cultured brain ECs on cell swelling in cultured astrocytes. CM from ammonia-treated ECs when added to astrocytes caused significant cell swelling, and such swelling was potentiated when astrocytes were exposed to CM from ECs-treated with a combination of ammonia, LPS and CKs. We also found an additive effect when astrocytes were exposed to ammonia along with CM from ammonia-treated ECs. Additionally, ECs treated with ammonia showed a significant increase in the production of oxy-radicals, nitric oxide, as well as evidence of oxidative/nitrative stress and activation of the transcription factor NF-κ B. CM derived from ECs treated with ammonia, along with antioxidants or the NF-κB inhibitor BAY 11-7082, when added to astrocytes resulted in a significant reduction in cell swelling, as compared to the effect of CM from ECs-treated only with ammonia. We also identified increased nuclear NF-κB expression in rat brain cortical ECs in the thioacetamide model of AHE. These studies suggest that endothelial cells significantly contribute to the astrocyte swelling/brain edema in AHE, likely as a consequence of oxidative

  12. Strain in shore fast ice due to incoming ocean waves and swell

    NASA Astrophysics Data System (ADS)

    Fox, Colin; Squire, Vernon A.

    1991-03-01

    Using a development from the theoretical model presented by Fox and Squire (1990), this paper investigates the strain field generated in shore fast ice by normally incident ocean waves and swell. After a brief description of the model and its convergence, normalized absolute strain (relative to a 1-m incident wave) is found as a function of distance from the ice edge for various wave periods, ice thicknesses, and water depths. The squared transfer function, giving the relative ability of incident waves of different periods to generate strain in the ice, is calculated, and its consequences are discussed. The ice is then forced with a Pierson-Moskowitz spectrum, and the consequent strain spectra are plotted as a function of penetration into the ice sheet. Finally, rms strain, computed as the incoherent sum of the strains resulting from energy in the open water spectrum, is found. The results have implications to the breakup of shore fast ice and hence to the floe size distribution of the marginal ice zone.

  13. Gliotoxin-induced swelling of astrocytes hinders diffusion in brain extracellular space via formation of dead-space microdomains.

    PubMed

    Sherpa, Ang Doma; van de Nes, Paula; Xiao, Fanrong; Weedon, Jeremy; Hrabetova, Sabina

    2014-07-01

    One of the hallmarks of numerous life-threatening and debilitating brain diseases is cellular swelling that negatively impacts extracellular space (ECS) structure. The ECS structure is determined by two macroscopic parameters, namely tortuosity (λ) and volume fraction (α). Tortuosity represents hindrance imposed on the diffusing molecules by the tissue in comparison with an obstacle-free medium. Volume fraction is the proportion of tissue volume occupied by the ECS. From a clinical perspective, it is essential to recognize which factors determine the ECS parameters and how these factors change in brain diseases. Previous studies demonstrated that dead-space (DS) microdomains increased λ during ischemia and hypotonic stress, as these pocket-like structures transiently trapped diffusing molecules. We hypothesize that astrocytes play a key role in the formation of DS microdomains because their thin processes have concave shapes that may elongate as astrocytes swell in these pathologies. Here we selectively swelled astrocytes in the somatosensory neocortex of rat brain slices with a gliotoxin DL-α-Aminoadipic Acid (DL-AA), and we quantified the ECS parameters using Integrative Optical Imaging (IOI) and Real-Time Iontophoretic (RTI) diffusion methods. We found that α decreased and λ increased during DL-AA application. During recovery, α was restored whereas λ remained elevated. Increase in λ during astrocytic swelling and recovery is consistent with the formation of DS microdomains. Our data attribute to the astrocytes an important role in determining the ECS parameters, and indicate that extracellular diffusion can be improved not only by reducing the swelling but also by disrupting the DS microdomains.

  14. Gliotoxin-induced swelling of astrocytes hinders diffusion in brain extracellular space via formation of dead-space microdomains

    PubMed Central

    SHERPA, ANG DOMA; VAN DE NES, PAULA; XIAO, FANRONG; WEEDON, JEREMY; HRABETOVA, SABINA

    2014-01-01

    One of the hallmarks of numerous life-threatening and debilitating brain diseases is cellular swelling that negatively impacts extracellular space (ECS) structure. The ECS structure is determined by two macroscopic parameters, namely tortuosity (λ) and volume fraction (α). Tortuosity represents hindrance imposed on the diffusing molecules by the tissue in comparison with an obstacle-free medium. Volume fraction is the proportion of tissue volume occupied by the ECS. From a clinical perspective, it is essential to recognize which factors determine the ECS parameters and how these factors change in brain diseases. Previous studies demonstrated that dead-space (DS) microdomains increased λ during ischemia and hypotonic stress, as these pocket-like structures transiently trapped diffusing molecules. We hypothesize that astrocytes play a key role in the formation of DS microdomains because their thin processes have concave shapes that may elongate as astrocytes swell in these pathologies. Here we selectively swelled astrocytes in the somatosensory neocortex of rat brain slices with a gliotoxin DL-α-Aminoadipic Acid (DL-AA), and we quantified the ECS parameters using Integrative Optical Imaging (IOI) and Real-Time Iontophoretic (RTI) diffusion methods. We found that α decreased and λ increased during DL-AA application. During recovery, α was restored whereas λ remained elevated. Increase in λ during astrocytic swelling and recovery is consistent with the formation of DS microdomains. Our data attribute to the astrocytes an important role in determining the ECS parameters, and indicate that extracellular diffusion can be improved not only by reducing the swelling but also by disrupting the DS microdomains. PMID:24687699

  15. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  16. Modification of SRIM-calculated dose and injected ion profiles due to sputtering, injected ion buildup and void swelling

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Toloczko, Mychailo B.; Bailey, Nathan; Garner, Frank A.; Gigax, Jonathan; Shao, Lin

    2016-11-01

    In radiation effects on materials utilizing self-ion irradiations, it is necessary to calculate the local displacement damage level and ion injection profile because of the short distance that self-ions travel in a material and because of the strong variation of displacement rate with depth in a specimen. The most frequently used tool for this is the software package called Stopping and Range of Ions in Matter (SRIM). A SRIM-calculated depth-dependent dose level is usually determined under the implicit assumption that the target does not undergo any significant changes in volume during the process, in particular SRIM ignores the effect of sputtering, injected ions, and void swelling on the redistribution of the dose and injected ion profiles. This approach become increasingly invalid as the ion fluence reaches ever higher levels, especially for low energy ion irradiations. The original surface is not maintained due to sputter-induced erosion, while within the irradiated region of the specimen, injected ions are adding material, and if void swelling is occurring, it is creating empty space. An iterative mathematical treatment of SRIM outputs to produce corrected dose and injected ion profiles based on these phenomenon and without regard to diffusion is presented along with examples of differences between SRIM-calculated values and corrected values over a range of typical ion energies. The intent is to provide the reader with a convenient tool for more accurately calculating dose and injected ion profiles for heavy-ion irradiations.

  17. Modification of SRIM-calculated dose and injected ion profiles due to sputtering, injected ion buildup and void swelling

    SciTech Connect

    Wang, Jing; Toloczko, Mychailo B.; Bailey, Nathan; Garner, Frank A.; Gigax, Jonathan; Shao, Lin

    2016-11-01

    In radiation effects on materials utilizing self-ion irradiations, it is necessary to calculate the local displacement damage level and ion injection profile because of the short distance that self-ions travel in a material and because of the strong variation of displacement rate with depth in a specimen. The most frequently used tool for this is the software package called Stopping and Range of Ions in Matter (SRIM). A SRIM-calculated depth-dependent dose level is usually determined under the implicit assumption that the target does not undergo any significant changes in volume during the process, in particular SRIM ignores the effect of sputtering, injected ions, and void swelling on the redistribution of the dose and injected atom profiles. This approach become increasingly invalid as the ion fluence reaches ever higher levels, especially for low energy ion irradiations. The original surface is not maintained due to sputter-induced erosion, while within the irradiated region of the specimen, injected ions are adding material, and if void swelling is occurring, it is creating empty space. An iterative mathematical treatment of SRIM outputs to produce corrected dose and injected atom profiles is presented along with examples differences between SRIM-calculated values and corrected values over a range of typical ion energies.

  18. Rigid swelling of sublingual caruncle area due to the salivary gland duct obstruction by a sialolith*

    PubMed Central

    Bernardes Filho, Fred; Martins, Gustavo; Alves, Andreia Oliveira; da Costa, José Ronaldo Vieira; Azulay, David Rubem; Azulay-Abulafia, Luna

    2014-01-01

    Sialolithiasis is the presence of calculus within the ductal system of a salivary gland. Among the diagnostic methods are inspection, palpation, checking the amount of saliva secreted and the identification of a sialolith. The authors present the case of a 37-year-old female patient with edema of the submandibular area and a bulging sublingual caruncle due to a calculus that obstructed the salivary gland ostium. PMID:25387506

  19. Molecular Mechanisms Involved in Tissue Swelling due to Injury and due to Exposure to Low Temperature and Massive Water and Electrolyte Loss in Diarrheal Disorders.

    DTIC Science & Technology

    1981-06-01

    shrink and swell in hyper - and hypotonic solutions when the polymer water system is enclosed in a regular dialysis tubing which is fully permeable to...indicate that a polymer water system can shrink and swell in the same manner as the living cells when they are placed in hyper - or hypotonic solutions...cell water would be highly hypotonic . As a result the cell is expected to shrink in a+normal Ringer solution containing Na of a concen- tration equal

  20. Brain abscess due to Trueperella bernardiae.

    PubMed

    Parha, Eleni; Alalade, Andrew; David, Karoly; Kaddour, Hesham; Degun, Paramjit; Namnyak, Simon

    2015-01-01

    We present the case of a brain abscess caused by a combination of rare organisms (Trueperella bernardiae and Peptoniphilus harei) in a patient with chronic suppurative otitis media that had been complicated by the presence of a cholesteatoma. The authors believe this is the first report published in the literature.

  1. Increased Toll-Like Receptor 4 in Cerebral Endothelial Cells Contributes to the Astrocyte Swelling and Brain Edema in Acute Hepatic Encephalopathy

    PubMed Central

    Jayakumar, A.R.; Tong, X.Y.; Curtis, K.M.; Ruiz-Cordero, R.; Abreu, M.T.; Norenberg, M.D.

    2013-01-01

    Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy (AHE). We recently reported that conditioned media (CM) from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In the present study we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiated such effects. Additionally, astrocytes exposed to CM from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein upregulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide (TAA), and that TAA-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in AHE, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents. PMID:24261962

  2. Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy.

    PubMed

    Jayakumar, Arumugam R; Tong, Xiao Y; Curtis, Kevin M; Ruiz-Cordero, Roberto; Abreu, Maria T; Norenberg, Michael D

    2014-03-01

    Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up-regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents.

  3. Brain-derived neurotrophic factor inhibits osmotic swelling of rat retinal glial (Müller) and bipolar cells by activation of basic fibroblast growth factor signaling.

    PubMed

    Berk, B-A; Vogler, S; Pannicke, T; Kuhrt, H; Garcia, T B; Wiedemann, P; Reichenbach, A; Seeger, J; Bringmann, A

    2015-06-04

    Water accumulation in retinal glial (Müller) and neuronal cells resulting in cellular swelling contributes to the development of retinal edema and neurodegeneration. Intravitreal administration of neurotrophins such as brain-derived neurotrophic factor (BDNF) is known to promote survival of retinal neurons. Here, we show that exogenous BDNF inhibits the osmotic swelling of Müller cell somata induced by superfusion of rat retinal slices or freshly isolated cells with a hypoosmotic solution containing barium ions. BDNF also inhibited the osmotic swelling of bipolar cell somata in retinal slices, but failed to inhibit the osmotic soma swelling of freshly isolated bipolar cells. The inhibitory effect of BDNF on Müller cell swelling was mediated by activation of tropomyosin-related kinase B (TrkB) and transactivation of fibroblast growth factor receptors. Exogenous basic fibroblast growth factor (bFGF) fully inhibited the osmotic swelling of Müller cell somata while it partially inhibited the osmotic swelling of bipolar cell somata. Isolated Müller cells displayed immunoreactivity of truncated TrkB, but not full-length TrkB. Isolated rod bipolar cells displayed immunoreactivities of both TrkB isoforms. Data suggest that the neuroprotective effect of exogenous BDNF in the retina is in part mediated by prevention of the cytotoxic swelling of retinal glial and bipolar cells. While BDNF directly acts on Müller cells by activation of TrkB, BDNF indirectly acts on bipolar cells by inducing glial release of factors like bFGF that inhibit bipolar cell swelling.

  4. Azadirachta indica ethanolic extract protects neurons from apoptosis and mitigates brain swelling in experimental cerebral malaria

    PubMed Central

    2013-01-01

    Background Cerebral malaria is a rapidly developing encephalopathy caused by the apicomplexan parasite Plasmodium falciparum. Drugs currently in use are associated with poor outcome in an increasing number of cases and new drugs are urgently needed. The potential of the medicinal plant Azadirachta indica (Neem) for the treatment of experimental cerebral malaria was evaluated in mice. Methods Experimental cerebral malaria was induced in mice by infection with Plasmodium berghei ANKA. Infected mice were administered with Azadirachta indica ethanolic extract at doses of 300, 500, or 1000 mg/kg intraperitoneally (i.p.) in experimental groups, or with the anti-malarial drugs chloroquine (12 mg/kg, i.p.) or artemether (1.6 mg/kg, i.p.), in the positive control groups. Treatment was initiated at the onset of signs of brain involvement and pursued for five days on a daily basis. Mice brains were dissected out and processed for the study of the effects of the extract on pyramidal cells’ fate and on markers of neuroinflammation and apoptosis, in the medial temporal lobe. Results Azadirachta indica ethanolic extract mitigated neuroinflammation, decreased the severity of brain oedema, and protected pyramidal neurons from apoptosis, particularly at the highest dose used, comparable to chloroquine and artemether. Conclusions The present findings suggest that Azadirachta indica ethanolic extract has protective effects on neuronal populations in the inflamed central nervous system, and justify at least in part its use in African and Asian folk medicine and practices. PMID:23984986

  5. Azadirachta indica ethanolic extract protects neurons from apoptosis and mitigates brain swelling in experimental cerebral malaria.

    PubMed

    Bedri, Selma; Khalil, Eltahir A; Khalid, Sami A; Alzohairy, Mohammad A; Mohieldein, Abdlmarouf; Aldebasi, Yousef H; Seke Etet, Paul Faustin; Farahna, Mohammed

    2013-08-29

    Cerebral malaria is a rapidly developing encephalopathy caused by the apicomplexan parasite Plasmodium falciparum. Drugs currently in use are associated with poor outcome in an increasing number of cases and new drugs are urgently needed. The potential of the medicinal plant Azadirachta indica (Neem) for the treatment of experimental cerebral malaria was evaluated in mice. Experimental cerebral malaria was induced in mice by infection with Plasmodium berghei ANKA. Infected mice were administered with Azadirachta indica ethanolic extract at doses of 300, 500, or 1000 mg/kg intraperitoneally (i.p.) in experimental groups, or with the anti-malarial drugs chloroquine (12 mg/kg, i.p.) or artemether (1.6 mg/kg, i.p.), in the positive control groups. Treatment was initiated at the onset of signs of brain involvement and pursued for five days on a daily basis. Mice brains were dissected out and processed for the study of the effects of the extract on pyramidal cells' fate and on markers of neuroinflammation and apoptosis, in the medial temporal lobe. Azadirachta indica ethanolic extract mitigated neuroinflammation, decreased the severity of brain oedema, and protected pyramidal neurons from apoptosis, particularly at the highest dose used, comparable to chloroquine and artemether. The present findings suggest that Azadirachta indica ethanolic extract has protective effects on neuronal populations in the inflamed central nervous system, and justify at least in part its use in African and Asian folk medicine and practices.

  6. Brain swelling during dialysis: A randomized trial comparing low-flux hemodialysis with pre-dilution hemodiafiltration
.

    PubMed

    Johansen, Niels; Kjaergaard, Krista Dybtved; Peters, Christian Daugaard; Pedersen, Michael; Jespersen, Bente; Jensen, Jens Dam

    2017-05-01

    Osmotic changes in plasma are assumed to cause cerebral swelling in hemodialysis patients. We investigated the acute effect of low-flux hemodialysis (HD) (removal of small molecules) and pre-dilution hemodiafiltration (pre-HDF) (additional removal of larger molecules) on cerebral compartment volumes using quantitative magnetic resonance imaging (MRI) in chronic uremic patients. Twelve patients underwent a session of HD and pre-HDF in a randomized crossover study with equal ultrafiltration. MRI was performed immediately before and after dialysis. A linear correlation was found between changes in gray matter and plasma osmolarity (HD: r2 = 0.83; HDF: r2 = 0.73) but not between changes in white matter volume and plasma osmolarity (HD: r2 = 0.02; HDF: r2 = 0.004). Total brain volume increased by 1.8 ± 1.7% (18.7 ± 17.4 mL) (mean ± SD) during HD and 2.0 ± 0.9% (22.3 ± 10.7 mL) during pre-HDF. Gray matter volume increased: HD 3.8% (from -3.6 to 9.7) and pre-HDF 4.2% (from -2.8 to 14.3). White matter volume did not change significantly. Reduction ratio of urea (molecular weight (MW) 0.06 kDa) (HD: 68%; pre-HDF: 69.7%) and β2-microglobulin (MW 11.7 kDa) (HD: -13.7%; pre-HDF: 67.2%) separated the treatments. This study showed that HD and pre-HDF caused equal acute cerebral swelling of the grey matter. This appeared to be driven by small solute change in plasma interacting linearly with gray matter volume regardless of additional removal of larger molecules or ultrafiltration.
.

  7. Leg Swelling

    MedlinePlus

    ... swelling. References Sterns RH. Pathophysiology and etiology of edema in adults. www.uptodate.com/home. Accessed Dec. 29, 2016. Edema. Merck Manual Professional Version. http://www.merckmanuals.com/ ...

  8. Selective vasopressin-1a receptor antagonist prevents brain edema, reduces astrocytic cell swelling and GFAP, V1aR and AQP4 expression after focal traumatic brain injury.

    PubMed

    Marmarou, Christina R; Liang, Xiuyin; Abidi, Naqeeb H; Parveen, Shanaz; Taya, Keisuke; Henderson, Scott C; Young, Harold F; Filippidis, Aristotelis S; Baumgarten, Clive M

    2014-09-18

    A secondary and often lethal consequence of traumatic brain injury is cellular edema that we posit is due to astrocytic swelling caused by transmembrane water fluxes augmented by vasopressin-regulated aquaporin-4 (AQP4). We therefore tested whether vasopressin 1a receptor (V1aR) inhibition would suppress astrocyte AQP4, reduce astrocytic edema, and thereby diminish TBI-induced edematous changes. V1aR inhibition by SR49059 significantly reduced brain edema after cortical contusion injury (CCI) in rat 5h post-injury. Injured-hemisphere brain water content (n=6 animals/group) and astrocytic area (n=3/group) were significantly higher in CCI-vehicle (80.5±0.3%; 18.0±1.4 µm(2)) versus sham groups (78.3±0.1%; 9.5±0.9 µm(2)), and SR49059 blunted CCI-induced increases in brain edema (79.0±0.2%; 9.4±0.8µm(2)). CCI significantly up-regulated GFAP, V1aR and AQP4 protein levels and SR49059 suppressed injury induced up regulation (n=6/group). In CCI-vehicle, sham and CCI-SR49059 groups, GFAP was 1.58±0.04, 0.47±0.02, and 0.81±0.03, respectively; V1aR was 1.00±0.06, 0.45±0.05, and 0.46±0.09; and AQP4 was 2.03±0.34, 0.49±0.04, and 0.92±0.22. Confocal immunohistochemistry gave analogous results. In CCI-vehicle, sham and CCI-SR49059 groups, fluorescence intensity of GFAP was 349±38, 56±5, and 244±30, respectively, V1aR was 601±71, 117.8±14, and 390±76, and AQP4 was 818±117, 158±5, and 458±55 (n=3/group). The results support that edema was predominantly cellular following CCI and documented that V1aR inhibition with SR49059 suppressed injury-induced up regulation of GFAP, V1A and AQP4, blunting edematous changes. Our findings suggest V1aR inhibitors may be potential therapeutic tools to prevent cellular swelling and provide treatment for post-traumatic brain edema.

  9. Brain abscess due to odontogenic infection: a case report

    PubMed Central

    Park, Sung Yong; Suh, Dong Won; Park, Chul Min; Oh, Min Seok

    2014-01-01

    In this report, we describe a case of brain abscess due to odontogenic infection. A 53-year-old female who had been suffering from headache and trismus for two weeks visited the Department of Oral and Maxillofacial Surgery at the Sun Dental Hospital (Daejeon, Korea). Even after several routine tests, we still could not make a diagnosis. However, after the combined multidisciplinary efforts of oral surgeons and neurosurgeons, the patient was treated for odontogenic infection and made an uneventful recovery. Therefore, patients with infections in the head and neck region showing symptoms such as headache, changes in mental state, nausea, vomiting, seizures, hemiplegia, speech disturbance, and visual disturbance, a brain abscess should be included in the list of differential diagnoses. PMID:25045643

  10. Brain abscess in seven cats due to a bite wound: MRI findings, surgical management and outcome.

    PubMed

    Costanzo, Chiara; Garosi, Laurent S; Glass, Eric N; Rusbridge, Clare; Stalin, Catherine E; Volk, Holger A

    2011-09-01

    PRESENTATION AND LESION LOCALISATION: Seven adult domestic shorthair cats were presented with a 1- to 6-day history of progressive neurological signs. A focal skin puncture and subcutaneous swelling over the dorsal part of the head were detected on physical examination. Neurological examination indicated lesion(s) in the right forebrain in four cats, multifocal forebrain in one cat, left forebrain in one cat, and multifocal forebrain and brainstem in the remaining cat. In all cats, magnetic resonance imaging revealed a space-occupying forebrain lesion causing a severe mass effect on adjacent brain parenchyma. CLINICAL APPROACH AND OUTCOME: All cats were managed with a combination of medical and surgical treatment. At surgery a small penetrating calvarial fracture was detected in all cats, and a tooth fragment was found within the content of the abscess in two cats. The combination of surgical intervention, intensive care and intravenous antimicrobials led to a return to normal neurological function in five cats. As this series of cases indicates, successful resolution of a brain abscess due to a bite injury depends on early recognition and combined used of antimicrobials and surgical intervention. A particular aim of surgery is to remove any skull and foreign body (tooth) fragments that may represent a continuing focus of infection. Copyright © 2011 ISFM and AAFP. All rights reserved.

  11. [Nuchal swelling].

    PubMed

    Breunig, C; Pfeiffer, J; Kaminsky, J; Ridder, G J

    2011-06-01

    In the unusual case of a 68-year-old woman with one-sided painless lateral neck swelling, the ENT examination showed a firm nuchal mass (4 × 4 cm) on the right side with no other pathological findings. Angio-MRI confirmed a solid, sharply demarcated tumor with arterial hyperperfusion. Core needle aspiration biopsy was performed, revealing well-circumscribed tufts showing the typical "cannonball" aspect. After preoperative embolisation we performed extirpation of the mass. Histological examination showed an acquired tufted angioma. Clinical as well as radiological follow-up examination detected neither local relapse nor metastases.

  12. Deep brain stimulation in addiction due to psychoactive substance use.

    PubMed

    Kuhn, Jens; Bührle, Christian P; Lenartz, Doris; Sturm, Volker

    2013-01-01

    Addiction is one of the most challenging health problems. It is associated with enormous individual distress and tremendous socioeconomic consequences. Unfortunately, its underlying mechanisms are not fully understood, and pharmacological, psychological, or social interventions often fail to achieve long-lasting remission. Next to genetic, social, and contextual factors, a substance-induced dysfunction of the brain's reward system is considered a decisive factor for the establishment and maintenance of addiction. Due to its successful application and approval for several neurological disorders, deep brain stimulation (DBS) is known as a powerful tool for modulating dysregulated networks and has also been considered for substance addiction. Initial promising case reports of DBS in alcohol and heroin addiction in humans have recently been published. Likewise, results from animal studies mimicking different kinds of substance addiction point in a similar direction. The objective of this review is to provide an overview of the published results on DBS in addiction, and to discuss whether these preliminary results justify further research, given the novelty of this treatment approach.

  13. Alpha-synuclein immunoreactivity is present in axonal swellings in neuroaxonal dystrophy and acute traumatic brain injury.

    PubMed

    Newell, K L; Boyer, P; Gomez-Tortosa, E; Hobbs, W; Hedley-Whyte, E T; Vonsattel, J P; Hyman, B T

    1999-12-01

    The primary neuroaxonal dystrophies (NAD), which include infantile NAD and Hallervorden-Spatz syndrome (HSS), are characterized by dystrophic terminal axons and axonal swellings. Lewy bodies have been found in some cases. In Parkinson disease (PD) and dementia with Lewy bodies (DLB), Lewy bodies and neurites display prominent alpha-synuclein immunoreactivity. We examined 2 cases of HSS and 4 cases of infantile NAD with alpha-synuclein immunohistochemistry to test the hypothesis that these disorders with similar morphological findings might share a biochemical phenotype. Furthermore, we compared them to 8 cases of secondary or physiologic NAD of various causes and 2 cases of recent traumatic head injury. Alpha-synuclein positive neuronal cytoplasmic inclusions, including Lewy bodies, and neurites were numerous in 1 HSS and 1 infantile NAD case. In addition, axonal spheroids were immunostained in all 6 cases of primary NAD, 5 cases of secondary NAD, and 2 cases of recent head injury. Axonal spheroids were faintly stained in the 3 physiologic NAD cases. Alpha-synuclein positive axonal swellings may suggest a mechanism, such as axonal injury, leading to the neuronal cytoplasmic accumulation of alpha-synuclein in NAD and other disorders.

  14. Extravascular compression of the femoral vein due to wear debris-induced iliopsoas bursitis: a rare cause of leg swelling after total hip arthroplasty.

    PubMed

    Beksaç, Burak; Tözün, Remzi; Baktiroglu, Selcuk; Sener, Nadir; Gonzalez Della Valle, Alejandro

    2007-04-01

    We present a patient with unilateral, spontaneous, late leg swelling that developed 4 years after total hip arthroplasty. The etiology was the compression of the internal iliac vein by a voluminous iliopsoas bursitis caused by polyethylene debris. The expansive lesion was detected by ultrasound, arthrography, and magnetic resonance imaging. An ultrasound-guided aspiration provided transient relief of the patient's symptoms. The patient later required surgical excision through an abdominal approach. A second recurrence was detected and treated with revision surgery. We present the diagnosis and the treatment of this rare cause of late, unilateral leg swelling after total hip arthroplasty together with a review of the literature.

  15. Safety and efficacy of intravenous glyburide on brain swelling after large hemispheric infarction (GAMES-RP): a randomised, double-blind, placebo-controlled phase 2 trial.

    PubMed

    Sheth, Kevin N; Elm, Jordan J; Molyneaux, Bradley J; Hinson, Holly; Beslow, Lauren A; Sze, Gordon K; Ostwaldt, Ann-Christin; Del Zoppo, Gregory J; Simard, J Marc; Jacobson, Sven; Kimberly, W Taylor

    2016-10-01

    Preclinical models of stroke have shown that intravenous glyburide reduces brain swelling and improves survival. We assessed whether intravenous glyburide (RP-1127; glibenclamide) would safely reduce brain swelling, decrease the need for decompressive craniectomy, and improve clinical outcomes in patients presenting with a large hemispheric infarction. For this double-blind, randomised, placebo-controlled phase 2 trial, we enrolled patients (aged 18-80 years) with a clinical diagnosis of large anterior circulation hemispheric infarction for less than 10 h and baseline diffusion-weighted MRI image lesion volume of 82-300 cm(3) on MRI at 18 hospitals in the USA. We used web-based randomisation (1:1) to allocate patients to the placebo or intravenous glyburide group. Intravenous glyburide was given as a 0·13 mg bolus intravenous injection for the first 2 min, followed by an infusion of 0·16 mg/h for the first 6 h and then 0·11 mg/h for the remaining 66 h. The primary efficacy outcome was the proportion of patients who achieved a modified Rankin Scale (mRS) score of 0-4 at 90 days without undergoing decompressive craniectomy. Analysis was by per protocol. Safety analysis included all randomly assigned patients who received the study drug. This trial is registered with ClinicalTrials.gov, number NCT01794182. Between May 3, 2013, and April 30, 2015, 86 patients were randomly assigned but enrolment was stopped because of funding reasons. The funder, principal investigators, site investigators, patients, imaging core, and outcomes personnel were masked to treatment. The per-protocol study population was 41 participants who received intravenous glyburide and 36 participants who received placebo. 17 (41%) patients in the intravenous glyburide group and 14 (39%) in the placebo group had an mRS score of 0-4 at 90 days without decompressive craniectomy (adjusted odds ratio 0·87, 95% CI 0·32-2·32; p=0·77). Ten (23%) of 44 participants in the intravenous glyburide group

  16. Hotspot swells revisited

    NASA Astrophysics Data System (ADS)

    King, Scott D.; Adam, Claudia

    2014-10-01

    The first attempts to quantify the width and height of hotspot swells were made more than 30 years ago. Since that time, topography, ocean-floor age, and sediment thickness datasets have improved considerably. Swell heights and widths have been used to estimate the heat flow from the core-mantle boundary, constrain numerical models of plumes, and as an indicator of the origin of hotspots. In this paper, we repeat the analysis of swell geometry and buoyancy flux for 54 hotspots, including the 37 considered by Sleep (1990) and the 49 considered by Courtillot et al. (2003), using the latest and most accurate data. We are able to calculate swell geometry for a number of hotspots that Sleep was only able to estimate by comparison with other swells. We find that in spite of the increased resolution in global bathymetry models there is significant uncertainty in our calculation of buoyancy fluxes due to differences in our measurement of the swells’ width and height, the integration method (volume integration or cross-sectional area), and the variations of the plate velocities between HS2-Nuvel1a (Gripp and Gordon, 1990) and HS3-Nuvel1a (Gripp and Gordon, 2002). We also note that the buoyancy flux for Pacific hotspots is in general larger than for Eurasian, North American, African and Antarctic hotspots. Considering that buoyancy flux is linearly related to plate velocity, we speculate that either the calculation of buoyancy flux using plate velocity over-estimates the actual vertical flow of material from the deep mantle or that convection in the Pacific hemisphere is more vigorous than the Atlantic hemisphere.

  17. Brain abscess due to Aggregatibacter aphrophilus and Bacteroides uniformis.

    PubMed

    Bogdan, Maja; Zujić Atalić, Vlasta; Hećimović, Ivan; Vuković, Dubravka

    2015-01-01

    The aim of this report was to describe the occurrence of a bacterial brain abscess in a healthy individual, without any predisposing condition. A thirteen-year old boy was admitted to the Department of Neurosurgery after the onset of vomiting, headache and dizziness. A neurological deficit was detected during the physical examination so urgent magnetic resonance imaging of the brain was performed, revealing an intrahemispheric, right positioned solitary expansive mass with ring enhancement. Purulent material was obtained during osteoplastic craniotomy with total extirpation of the brain abscess. Aggregatibacter aphrophilus and Bacteroides uniformis were isolated. The patient's general condition improved and the neurological deficit subsided as a result of the prompt recognition and treatment of this life threatening condition. To achieve a favourable clinical outcome, prompt recognition and surgical treatment of a brain abscess are of primary importance,followed by administration of appropriate antimicrobial therapy. To our best knowledge, this is the first report of this combination of microorganisms as the cause of a brain abscess. Copyright © 2015 by Academy of Sciences and Arts of Bosnia and Herzegovina.

  18. Venous or arterial blood components trigger more brain swelling, tissue death after acute subdural hematoma compared to elderly atrophic brain with subdural effusion (SDE) model rats.

    PubMed

    Wajima, Daisuke; Sato, Fumiya; Kawamura, Kenya; Sugiura, Keisuke; Nakagawa, Ichiro; Motoyama, Yasushi; Park, Young-Soo; Nakase, Hiroyuki

    2017-09-01

    Acute subdural hematoma (ASDH) is a frequent complication of severe head injury, whose secondary ischemic lesions are often responsible for the severity of the disease. We focused on the differences of secondary ischemic lesions caused by the components, 0.4ml venous- or arterial-blood, or saline, infused in the subdural space, evaluating the differences in vivo model, using rats. The saline infused rats are made for elderly atrophic brain with subdural effusion (SDE) model. Our data showed that subdural blood, both venous- and arterial-blood, aggravate brain edema and lesion development more than SDE. This study is the first study, in which different fluids in rats' subdural space, ASDH or SDE are compared with the extension of early and delayed brain damage by measuring brain edema and histological lesion volume. Blood constituents started to affect the degree of ischemia underneath the subdural hemorrhage, leading to more pronounced breakdown of the blood-brain barrier and brain damage. This indicates that further strategies to treat blood-dependent effects more efficiently are in view for patients with ASDH. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Cinnamon polyphenols attenuate cell swelling and mitochondrial dysfunction following oxygen-glucose deprivation in glial cells

    USDA-ARS?s Scientific Manuscript database

    Astrocyte swelling is an integral component of cytotoxic brain edema in ischemic injury. While mechanisms underlying astrocyte swelling are likely multifactorial, oxidative stress and mitochondrial dysfunction are hypothesized to contribute to such swelling. We investigated the protective effects of...

  20. Sterile brain abscess due to juvenile xanthogranuloma: DWI characteristics.

    PubMed

    Kwak, Ellie S; Marrero, Daniel E; Pfannl, Rolf; Erbay, Sami H

    2013-07-01

    Juvenile xanthogranuloma (JXG) is a disorder of non-Langerhans cell histiocytosis that usually displays as a self-limiting course in children. Rare systemic involvement implies poor prognosis. Although conventional and spectroscopic magnetic resonance imaging (MRI) findings of JXG in CNS have been described, diffusion imaging of intracranial JXG has not been reported. Our case report is the first manuscript to describe diffusion restriction of a cerebral lesion seen in the setting of JXG. Since diffusion restriction has not been described in the setting of JXG but it is more commonly associated with infectious cerebral abscess, this finding has had significant impact in the management. Central nervous system (CNS) lesion of our patient has also had additional imaging features similar to typical infectious cerebral abscess. Extensive work-up has been unrevealing any infectious source. Patient has had biopsy proven peripheral sterile abscesses. After extensive discussion with the family, brain biopsy is deferred. Intravenous steroid therapy is initiated in intensive care setting. All of the lesions have gradually responded to steroid therapy. CNS lesion has taken the longest time to clear. Copyright © 2012 by the American Society of Neuroimaging.

  1. Encephalopathy and death in infants with abusive head trauma is due to hypoxic-ischemic injury following local brain trauma to vital brainstem centers.

    PubMed

    Matschke, Jakob; Büttner, Andreas; Bergmann, Markus; Hagel, Christian; Püschel, Klaus; Glatzel, Markus

    2015-01-01

    Infants with abusive head trauma (AHT) have diffuse brain damage with potentially fatal brain swelling. The pathogenesis of the brain damage remains unclear. We hypothesize that brain damage in AHT is due to hypoxic-ischemic injury with hypoxic-ischemic encephalopathy (HIE) rather than primary traumatic brain injury (TBI) with traumatic diffuse axonal injury (tDAI). We studied brain tissue of AHT victims. Primary outcome measure was the presence of primary traumatic versus hypoxic-ischemic brain injury. The diagnosis of tDAI followed a standardized semiquantitative diagnostic approach yielding a 4-tiered grading scheme (definite, possible, improbable, and none). In addition, results of quantitative immunohistochemical analysis in a subgroup of AHT victims with instant death were compared with matched SIDS controls. In our cohort of 50 AHT victims, none had definite tDAI (no tDAI in 30, tDAI possible in 2, and tDAI improbable in 18). Instead, all AHT victims showed morphological findings indicative of HIE. Furthermore, the subgroup with instant death showed significantly higher counts of damaged axons with accumulation of amyloid precursor protein (APP) in the brainstem adjacent to the central pattern generator of respiratory activity (CPG) (odds ratio adjusted for age, sex, brain weight, and APP-count in other regions = 3.1; 95 % confidence interval = 1.2 to 7.7; p = 0.015). AHT victims in our cohort do not have diffuse TBI or tDAI. Instead, our findings indicate that the encephalopathy in AHT is the due to hypoxic-ischemic injury probably as the result of respiratory arrest due to local damage to parts of the CPG in the brainstem.

  2. Brain injury due to anaphylactic shock as a result of formocresol used during root canal treatment.

    PubMed

    Ding, Y-J; Song, H; Liu, J-H; Wang, G-H

    2013-10-01

    Formocresol is still used in many parts of the world despite concerns over its toxicity. A case of a 45-year-old women who experienced brain injury after an analyphlactic reaction to formocresol is presented. During routine root canal treatment, the patient experienced nausea and vomiting after formocresol was used as an antibacterial agent in the pulp chamber. The procedure was discontinued and the symptoms resolved. Four days later, the treatment was continued by a different dentist, and the patient developed anaphylactic shock within 10 min of placement of a formocresol-soaked cotton pellet. She received emergency medical treatment and magnetic resonance imaging (MRI) revealed brain injury characterized by swelling of the gyrus in the cerebral watershed territory of the left parietal-occipital lobe. The patient subsequently made a full recovery after supportive treatment. A type-I allergic reaction can be induced by formocresol. The reasons for the brain injury are thought to be cerebral hypoxia, which was induced by the anaphylactic shock and/or cerebral parenchymal oedema. All dentists should be aware of the risks involved in the use of formocresol and avoid using materials containing formocresol and related agents. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  3. Decreased STAT3 Phosphorylation Mediates Cell Swelling in Ammonia-Treated Astrocyte Cultures

    PubMed Central

    Jayakumar, Arumugam R.; Curtis, Kevin M.; Panickar, Kiran S.; Shamaladevi, Nagarajarao; Norenberg, Michael D.

    2016-01-01

    Brain edema, due largely to astrocyte swelling, and the subsequent increase in intracranial pressure and brain herniation, are major complications of acute liver failure (ALF). Elevated level of brain ammonia has been strongly implicated in the development of astrocyte swelling associated with ALF. The means by which ammonia brings about astrocyte swelling, however, is incompletely understood. Recently, oxidative/nitrosative stress and associated signaling events, including activation of mitogen-activated protein kinases (MAPKs), as well as activation of the transcription factor, nuclear factor-kappaB (NF-κB), have been implicated in the mechanism of ammonia-induced astrocyte swelling. Since these signaling events are known to be regulated by the transcription factor, signal transducer and activator of transcription 3 (STAT3), we examined the state of STAT3 activation in ammonia-treated cultured astrocytes, and determined whether altered STAT3 activation and/or protein expression contribute to the ammonia-induced astrocyte swelling. STAT3 was found to be dephosphorylated (inactivated) at Tyrosine705 in ammonia-treated cultured astrocytes. Total STAT3 protein level was also reduced in ammonia-treated astrocytes. We also found a significant increase in protein tyrosine phosphatase receptor type-1 (PTPRT-1) protein expression in ammonia-treated cultured astrocytes, and that inhibition of PTPRT-1 enhanced the phosphorylation of STAT3 after ammonia treatment. Additionally, exposure of cultured astrocytes to inhibitors of protein tyrosine phosphatases diminished the ammonia-induced cell swelling, while cultured astrocytes over-expressing STAT3 showed a reduction in the astrocyte swelling induced by ammonia. Collectively, these studies strongly suggest that inactivation of STAT3 represents a critical event in the mechanism of the astrocyte swelling associated with acute liver failure. PMID:27918421

  4. Calcium in the Mechanism of Ammonia-Induced Astrocyte Swelling

    PubMed Central

    Jayakumar, A.R.; Rao, K.V. Rama; Tong, X.Y; Norenberg, M.D.

    2016-01-01

    Brain edema, due largely to astrocyte swelling, is an important clinical problem in patients with acute liver failure. While mechanisms underlying astrocyte swelling in this condition are not fully understood, ammonia and associated oxidative/nitrosative stress (ONS) appear to be involved. Mechanisms responsible for the increase in reactive oxygen/nitrogen species (RONS) and their role in ammonia-induced astrocyte swelling, however, are poorly understood. Recent studies have demonstrated a transient increase in intracellular Ca2+ in cultured astrocytes exposed to ammonia. As Ca2+ is a known inducer of RONS, we investigated potential mechanisms by which Ca2+ may be responsible for the production of RONS and cell swelling in cultured astrocytes after treatment with ammonia. Exposure of cultured astrocytes to ammonia (5 mM) increased the formation of free radicals, including nitric oxide, and such increase was significantly diminished by treatment with the Ca2+ chelator BAPTA-AM. We then examined the activity of Ca2+-dependent enzymes that are known to generate RONS and found that ammonia significantly increased the activities of NADPH oxidase (NOX), constitutive nitric oxide synthase (cNOS) and phospholipase A2 (PLA2) and such increases in activity were significantly diminished by BAPTA. Pretreatment of cultures with 7-nitroindazole, apocyanin and quinacrine, respective inhibitors of cNOS, NOX and PLA2, all significantly diminished RONS production. Additionally, treatment of cultures with BAPTA or with inhibitors of cNOS, NOX and PLA2 reduced ammonia-induced astrocyte swelling. These studies suggest that the ammonia-induced rise in intracellular Ca2+ activates free radical producing enzymes that ultimately contribute to the mechanism of astrocyte swelling. PMID:19393035

  5. [Personality Change due to Brain Trauma Caused by Traffic Accidents and Its Assessment of Psychiatric Impairment].

    PubMed

    Fan, Hui-yu; Zhang, Qin-ting; Tang, Tao; Cai, Wei-xiong

    2016-04-01

    To explore the main performance of personality change in people with mild psychiatric impairments which due to the brain trauma caused by traffic accidents and its value in assessment of psychiatric impairment. The condition of personality change of patients with traumatic brain injury caused by traffic accident was evaluated by the Scale of Personality Change Post-traumatic Brain Injury (SPCPTBI). Furthermore, the correlation between the personality change and the degrees of traumatic brain injury and psychiatric impairment were explored. Results In 271 samples, 239 (88.2%) with personality changes. Among these 239 samples, 178 (65.7%), 46 (17.0%), 15 (5.5%) with mild, moderate and severe personality changes, respectively. The ratio based on the extent of personality changes to the degree of brain trauma was not significant (P > 0.05), but the total score difference between the groups was significant (P < 0.05). There was no statistical significance between the medium and high severity brain trauma groups. The higher degree of personality changes, the higher rank of mental disabilities. The total score difference of the scale of personality change among the different mild psychiatric impairment group was significant (P<0.05). The difference between other psychiatric impairment levels had statistical significance (P < 0.05) except level 7 and 8. The occurrence of personality change due to traumatic brain injury caused by traffic accident was high. Correlations exist between the personality change and the degree of psychiatric impairment. Personality change due to brain trauma caused by traffic accident can be assessed effectively by means of SPCPTBI, and the correlation between the total score and the extent of traumatic brain injury can be found.

  6. Visual hallucinations of autobiographic memory and asomatognosia: a case of epilepsy due to brain cysticercosis.

    PubMed

    Orjuela-Rojas, Juan Manuel; Ramírez-Bermúdez, Jesús; Martínez-Juárez, Iris E; Kerik, Nora Estela; Diaz Meneses, Iván; Pérez-Gay, Fernanda Juárez

    2015-01-01

    The current study describes the case of a woman with symptomatic epilepsy due to brain cysticercosis acquired during childhood. During her adolescence, she developed seizures characterized by metamorphopsia, hallucinations of autobiographic memory and, finally, asomatognosia. Magnetic brain imaging showed a calcified lesion in the right occipitotemporal cortex, and positron emission tomography imaging confirmed the presence of interictal hypometabolism in two regions: the right parietal cortex and the right lateral and posterior temporal cortex. We discuss the link between these brain areas and the symptoms described under the concepts of epileptogenic lesion, epileptogenic zone, functional deficit zone, and symptomatogenic zone.

  7. Activation of the ACE2/Ang-(1-7)/Mas pathway reduces oxygen-glucose deprivation induced tissue swelling, ROS production, and cell death in mouse brain with angiotensin II overproduction

    PubMed Central

    Zheng, Jiaolin; Li, Guangze; Chen, Shuzhen; Chen, Ji; Buck, Joshua; Zhu, Yulan; Xia, Huijing; Lazartigues, Eric; Chen, Yanfang; Olson, James E.

    2014-01-01

    We previously demonstrated that mice which overexpress human renin and angiotensinogen (R+A+) show enhanced cerebral damage in both in vivo and in vitro experimental ischemia models. Angiotensin converting enzyme 2 (ACE2) counteracts the effects of angiotensin (Ang-II) by transforming it into Ang-(1-7), thus reducing the ligand for the AT1 receptor and increasing stimulation of the Mas receptor. Triple transgenic mice, SARA, which specifically overexpress ACE2 in neurons of R+A+ mice were used to study the role of ACE2 in ischemic stroke using oxygen and glucose deprivation (OGD) of brain slices as an in vitro model. We examined tissue swelling, the production of reactive oxygen species (ROS), and cell death in cerebral cortex (CX) and the hippocampal CA1 region during OGD. Expression levels of NADPH oxidase isoforms, Nox2 and Nox4 were measured using western blots. Results show that SARA mice and R+A+ mice treated with the Mas receptor agonist Ang-(1-7) had less swelling, cell death, and ROS production in CX and CA1 areas compared to those in R+A+ animals. Treatment of slices from SARA mice with the Mas antagonist A779 eliminated this protection. Finally, western blots revealed less Nox2 and Nox4 expression in SARA mice compared with R+A+ mice both before and after OGD. We suggest that reduced brain swelling and cell death observed in SARA animals exposed to OGD results from diminished ROS production coupled with lower expression of NADPH oxidases. Thus, the ACE2/Ang-(1-7)/Mas receptor pathway plays a protective role in brain ischemic damage by counteracting the detrimental effects of Ang-II-induced ROS production. PMID:24814023

  8. A thoracic mechanism of mild traumatic brain injury due to blast pressure waves.

    PubMed

    Courtney, A C; Courtney, M W

    2009-01-01

    The mechanisms by which blast pressure waves cause mild-to-moderate traumatic brain injury (mTBI) are an open question. Possibilities include acceleration of the head, direct passage of the blast wave via the cranium, and propagation of the blast wave to the brain via a thoracic mechanism. The hypothesis that the blast pressure wave reaches the brain via a thoracic mechanism is considered in light of ballistic and blast pressure wave research. Ballistic pressure waves, caused by penetrating ballistic projectiles or ballistic impacts to body armor, can only reach the brain via an internal mechanism and have been shown to cause cerebral effects. Similar effects have been documented when a blast pressure wave has been applied to the whole body or focused on the thorax in animal models. While vagotomy reduces apnea and bradycardia due to ballistic or blast pressure waves, it does not eliminate neural damage in the brain, suggesting that the pressure wave directly affects the brain cells via a thoracic mechanism. An experiment is proposed which isolates the thoracic mechanism from cranial mechanisms of mTBI due to blast wave exposure. Results have implications for evaluating risk of mTBI due to blast exposure and for developing effective protection.

  9. Marquesas-Line Swell

    SciTech Connect

    Crough, S.T.; Jarrard, R.D.

    1981-12-10

    Mapping of depth anomalies in the central Pacific reveals a broad, shallow region herein termed the Marquesas--Line Swell. It has the morphology and geoid signature typical of a midplate hotspot swell and probably marks the Tertiary trace of the Marquesas hotspot. The swell is elongate in the NW--SE direction, about 800 m high, and about 1500 km wide. It appears to extend continuously between the Marquesas Islands and the Line Cross Trend. A positive geoid height anomaly over the swell can be separated from the large regional trend. The transfer function between depth anomaly and geoid height is not well defined but is consistent with local isostatic compensation with an average root depth about 30 km ( +- 40 km, 95% confidence interval) below the swell's surface. Direct spatial comparisons between geoid height and depth anomaly suggest that this root depth is constant along the length of the swell and has a value of about 40 km ( +- 10 km, 95% confidence interval). The crest of the swell appears to subside as normal seafloor which is only 25 m.y. old, the prediction of the lithospheric thinning hypothesis. A permanent density decrease within the lithosphere can also explain the subsidence and geoid height anomaly; roll-cell dynamic up-lift can explain the subsidence but is difficult to reconcile with the geoid data.

  10. Shales and swelling soils

    NASA Astrophysics Data System (ADS)

    Franklin, J. A.; Dimillio, A. F.; Strohm, W. E., Jr.; Vandre, B. C.; Anderson, L. R.

    The thirteen (13) papers in this report deal with the following areas: a shale rating system and tentative applications to shale performance; technical guidelines for the design and construction of shale embankments; stability of waste shale embankments; dynamic response of raw and stabilized Oklahoma shales; laboratory studies of the stabilization of nondurable shales; swelling shale and collapsing soil; development of a laboratory compaction degradation test for shales; soil section approach for evaluation of swelling potential soil moisture properties of subgrade soils; volume changes in compacted clays and shales on saturation; characterization of expansive soils; pavement roughness on expansive clays; and deep vertical fabric moisture barriers in swelling soils.

  11. Swelling of Olympic Gels

    NASA Astrophysics Data System (ADS)

    Lang, M.; Fischer, J.; Werner, M.; Sommer, J.-U.

    2014-06-01

    The swelling equilibrium of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo simulations. In contrast to chemically cross-linked polymer networks, we observe that Olympic gels made of chains with a larger degree of polymerization, N, exhibit a smaller equilibrium swelling degree, Q∝N-0.28ϕ0-0.72, at the same polymer volume fraction ϕ0 at network preparation. This observation is explained by a desinterspersion (reorganization with release of nontrapped entanglements) process of overlapping nonconcatenated rings upon swelling.

  12. [Three cases of brain injury due to windshield impact (author's transl)].

    PubMed

    Isu, T; Abe, H; Aida, T; Iwakuma, T

    1979-04-01

    Three cases of brain injury due to windshield impact (tempered windshield) were reported. In the case of brain injury, multitude of small cracks injured the frontal lobe through the orbital roof with facial injuries due to windshield impact. Though we are apt to misdiagnose because of very small wounds, the diagnosis can be made easily from the plain film. The craniotomy, with complete removal of glass fragments and dural plasty, must be performed for the purpose of preventing infection and cerebrospinal fluid rhinorrhea. We believe that the use of seat belt and H.P.R. type laminated windshield is the best precaution against the windshield impact.

  13. Foot, leg, and ankle swelling

    MedlinePlus

    ... feet - legs; Ankle swelling; Foot swelling; Leg swelling; Edema - peripheral; Peripheral edema ... 51. Trayes KP, Studdiford JS, Pickle S, Tully AS. Edema: Diagnosis and management. Am Fam Phys . 2013;88( ...

  14. Relationship between light scattering and absorption due to cytochrome c oxidase reduction during loss of tissue viability in brains of rats

    NASA Astrophysics Data System (ADS)

    Kawauchi, Satoko; Sato, Shunichi; Ooigawa, Hidetoshi; Nawashiro, Hiroshi; Ishihara, Miya; Kikuchi, Makoto

    2008-02-01

    We performed simultaneous measurement of light scattering and absorption due to reduction of cytochrome c oxidase as intrinsic optical signals that are related to morphological characteristics and energy metabolism, respectively, for rat brains after oxygen/glucose deprivation by saline infusion. To detect change in light scattering, we determined the wavelength that was the most insensitive to change in light absorption due to the reduction of cytochrome c oxidase on the basis of multiwavelength analysis of diffuse reflectance data set for each rat. Then the relationships between scattering signal and absorption signals related to the reductions of heme aa 3 (605 nm) and CuA (830 nm) in cytochrome c oxidase were examined. Measurements showed that after starting saline infusion, the reduction of heme aa 3 started first; thereafter triphasic, large scattering change occurred (200-300 s), during which the reduction of CuA started. Despite such complex behaviors of IOSs, almost linear correlations were seen between the scattering signal and the heme aa 3-related absorption signal, while a relatively large animal-to-animal variation was observed in the correlation between the scattering signal and CuA-related absorption signal. Transmission electron microscopic observation revealed that dendritic swelling and mitochondrial deformation occurred in the cortical surface tissue after the triphasic scattering change. These results suggest that mitochondrial energy failure accompanies morphological alteration in the brain tissue and results in change in light scattering; light scattering will become an important indicator of tissue viability in brain.

  15. Swelling of percolation clusters

    NASA Astrophysics Data System (ADS)

    Schulz, Michael

    1992-10-01

    The swelling of percolation clusters as models for gelling branched polymers is analyzed by using a simple mean-field approach (for all dimensions) and a Monte-Carlo simulation (for d=3, bond fluctuation method). The numerical swelling exponent μ '=0.443 ± 0.008 shows a significant deviation from the lattice animals solution μ '=0.5, which is caused by the difference between quenched and annealed average procedures.

  16. [Brain abscess due to Fusobacterium necrophorum in a patient with convulsion and no signs of meningitis].

    PubMed

    Shimohata, Mitsuteru; Naruse, Satoshi; Kawasaki, Satoshi; Watanabe, Yumiko; Koyama, Miyako; Ito, Yasushi; Tanaka, Hajime

    2012-01-01

    Here, we report brain abscess due to Fusobacterium necrophorum (F. necrophorum) in a 78-year-old healthy man. He developed convulsion and did not have any signs of meningitis. Although the brain magnetic resonance imaging findings of the left occipital lobe were typical of a brain abscess, his cerebrospinal fluid examination revealed only slight pleocytosis and mild increase in protein levels. Thus, it was difficult to rule out the possibility of metastatic brain tumor; the patient's condition was provisionally diagnosed as symptomatic epilepsy secondary to brain abscess. His convulsion disappeared soon after administration of antiepileptic, antibacterial, and steroid agents. A craniotomy was performed to evacuate the abscess, and F. necrophorum was identified by culturing the abscess contents. After the operation, he was treated with appropriate antibacterial agents, which resulted in resolution of the brain abscess. Although Fusobacterium species are gram-negative anaerobic bacilli commensal of the human oropharynx, we need to recognize that Fusobacterium species can be a primary pathogen causing brain abscesses and may leave residual neurological sequelae without early appropriate treatment.

  17. Infiltration in Swelling Soils

    NASA Astrophysics Data System (ADS)

    Giraldez, Juan V.; Sposito, Garrison

    1985-01-01

    Infiltration phenomena in swelling soils were investigated theoretically. The approach taken consisted of applying both the approximate analytical techniques developed by J.-Y. Parlange and co-workers and conventional finite difference numerical methods to study the generalized Richards equation for one-dimensional infiltration in a swelling soil. Equations were derived for the ponding time and the post-ponding infiltration rate that are generalizations of the Parlange-Smith model expressions for rigid soils. Ponding times for swelling soils were shown to be shorter than those for nonswelling analogs, and post-ponding infiltration rates in swelling soils were shown to approach zero instead of becoming equal to the hydraulic conductivity, as in rigid soils. These results were confirmed, both qualitatively and quantitatively, with the numerical model, which also provided instantaneous moisture profiles and surface swelling predictions in agreement with field observations. A three-parameter infiltration equation proposed recently by J.-Y. Parlange et al. (1982) was generalized to describe swelling soils and shown to be in good agreement with published laboratory and field data. It appears that the generalized analytical model equations developed can be employed conveniently in hydrologic applications which do not require high accuracy in predictions.

  18. Patterns in swelling hydrogels

    NASA Astrophysics Data System (ADS)

    MacMinn, Chris; Bertrand, Thibault; Peixinho, Jorge; Mukhopadhyay, Shomeek

    2016-11-01

    Swelling is a process in which a porous material spontaneously grows by absorbing additional pore fluid. Polymeric hydrogels are highly deformable materials that can experience very large volume changes during swelling. This allows a small amount of dry gel to absorb a large amount of fluid, making gels extremely useful in applications from moisture control to drug delivery. However, a well-known consequence of these extreme volume changes is the emergence of a striking morphological instability. We study the transient mechanics of this instability here by combining a theoretical model with a series of simple experiments, focusing on the extent to which this instability can be controlled by manipulating the rate of swelling.

  19. Hereditary hemorrhagic telangiectasia patient presenting with brain abscess due to silent pulmonary arteriovenous malformation.

    PubMed

    Themistocleous, Marios; Giakoumettis, Dimitrios; Mitsios, Andreas; Anagnostopoulos, Christos; Kalyvas, Aristoteles; Koutsarnakis, Christos

    2016-01-01

    Hereditary hemorrhagic telangiectasia is a rare autosomal dominant inherited disease that is usually complicated by visceral vascular malformations. Patients harboring such malformations are at increased risk of brain abscess formation, which despite advances in diagnostic and surgical methods remains a life threatening medical emergency with high mortality and morbidity rates. In the present report we describe a case of cerebral abscess due to silent pulmonary arteriovenous malformation (AVM) in a young patient previously undiagnosed for hereditary hemorrhagic telangiectasia syndrome (HHT).

  20. Brain strain uncertainty due to shape variation in and simplification of head angular velocity profiles.

    PubMed

    Zhao, Wei; Ji, Songbai

    2017-04-01

    Head angular velocity, instead of acceleration, is more predictive of brain strains. Surprisingly, no study exists that investigates how shape variation in angular velocity profiles affects brain strains, beyond characteristics such as peak magnitude and impulse duration. In this study, we evaluated brain strain uncertainty due to variation in angular velocity profiles and further compared with that resulting from simplifying the profiles into idealized shapes. To do so, we used reconstructed head impacts from American National Football League for shape extraction and simulated head uniaxial coronal rotations from onset to full stop. The velocity profiles were scaled to maintain an identical peak velocity magnitude and duration in order to isolate the shape for investigation. Element-wise peak maximum principal strains from 44 selected impacts were obtained. We found that the shape of angular velocity profile could significantly affect brain strain magnitude (e.g., percentage difference of 4.29-17.89 % in the whole brain relative to the group average, with cumulative strain damage measure (CSDM) uncertainty range of 23.9 %) but not pattern (correlation coefficient of 0.94-0.99). Strain differences resulting from simplifying angular velocity profiles into idealized shapes were largely within the range due to shape variation, in both percentage difference and CSDM (signed difference of 3.91 % on average, with a typical range of 0-6 %). These findings provide important insight into the uncertainty or confidence in the performance of kinematics-based injury metrics. More importantly, they suggest the feasibility to simplify head angular velocity profiles into idealized shapes, at least within the confinements of the profiles evaluated, to enable real-time strain estimation via pre-computation in the future.

  1. Characteristics of brain stem auditory evoked potentials in children with hearing impairment due to infectious diseases.

    PubMed

    Ječmenica, Jovana Radovan; Opančina, Aleksandra Aleksandar Bajec

    2015-05-01

    Among objective audiologic tests, the most important were tests of brain stem auditory evoked potentials. The objective of the study was to test the configuration, degree of hearing loss, and response characteristics of auditory brain stem evoked potentials in children with hearing loss occurred due to infectious disease. A case control study design was used. The study group consisted of 54 patients referred for a hearing test because of infectious diseases caused by other agents or that occurred as congenital infection. Infectious agents have led to the emergence of various forms of sensorineural hearing loss. We have found deviations from the normal values of absolute and interwave latencies in some children in our group. We found that in the group of children who had the diseases such as purulent meningitis, or were born with rubella virus and cytomegalovirus infection, a retrocochlear damage was present in children with and without cochlear damage. © The Author(s) 2014.

  2. Swelling transition of a clay induced by heating

    PubMed Central

    Hansen, E. L.; Hemmen, H.; Fonseca, D. M.; Coutant, C.; Knudsen, K. D.; Plivelic, T. S.; Bonn, D.; Fossum, J. O.

    2012-01-01

    Clays are of paramount importance for soil stability, but also in applications ranging from oil recovery to composites and hydrogels. Generically, clays are divided into two subclasses: macroscopically swelling, ‘active’ clays that have the capacity for taking up large amounts of water to form stable gels, and ‘passive’ or non-swelling clays; the former stabilize soils whereas the latter are known to lead to landslides. However, it has been unclear so far what mechanisms underlie clay swelling. Here, we report the first observation of a temperature-induced transition from a passive to an active, swelling clay. We propose a simple description of the swelling transition; while net attractive interactions are dominant at low temperatures so that the clay particles remain attached to each other in stacks, at higher temperatures it is energetically favourable for the clay to swell due to the entropy that is gained by counterions which are liberated during swelling. PMID:22943004

  3. Electromagnetic power absorption and temperature changes due to brain machine interface operation.

    PubMed

    Ibrahim, Tamer S; Abraham, Doney; Rennaker, Robert L

    2007-05-01

    To fully understand neural function, chronic neural recordings must be made simultaneously from 10s or 100s of neurons. To accomplish this goal, several groups are developing brain machine interfaces. For these devices to be viable for chronic human use, it is likely that they will need to be operated and powered externally via a radiofrequency (RF) source. However, RF exposure can result in tissue heating and is regulated by the FDA/FCC. This paper provides an initial estimate of the amount of tissue heating and specific absorption rate (SAR) associated with the operation of a brain-machine interface (BMI). The operation of a brain machine interface was evaluated in an 18-tissue anatomically detailed human head mesh using simulations of electromagnetics and bio-heat phenomena. The simulations were conducted with a single chip, as well as with eight chips, placed on the surface of the human brain and each powered at four frequencies (13.6 MHz, 1.0 GHz, 2.4 GHz, and 5.8 GHz). The simulated chips consist of a wire antenna on a silicon chip covered by a Teflon dura patch. SAR values were calculated using the finite-difference time-domain method and used to predict peak temperature changes caused by electromagnetic absorption in the head using two-dimensional bio-heat equation. Results due to SAR alone show increased heating at higher frequencies, with a peak temperature change at 5.8 GHz of approximately 0.018 degrees C in the single-chip configuration and 0.06 degrees C in the eight-chip configuration with 10 mW of power absorption (in the human head) per chip. In addition, temperature elevations due to power dissipation in the chip(s) were studied. Results show that for the neural tissue, maximum temperature rises of 3.34 degrees C in the single-chip configuration and 7.72 degrees C in the eight-chip configuration were observed for 10 mW dissipation in each chip. Finally, the maximum power dissipation allowable in each chip before a 1.0 degrees C temperature

  4. Psychotic disorder due to traumatic brain injury: analysis of case studies in the literature.

    PubMed

    Fujii, Daryl; Fujii, Daniel C

    2012-01-01

    The present study utilized methodology from a previous descriptive study that analyzed case studies of psychotic disorder due to traumatic brain injury (PD-TBI) reported in psychiatry and neurology journals. The purpose was to replicate findings from the PD-TBI literature and to elucidate a pattern of characteristics that would differentiate PD-TBI from schizophrenia. The findings supported both objectives. PD-TBI data were highly consistent with previous studies: PD-TBI differed from schizophrenia in showing more focal frontal and temporal abnormalities on neurological studies and a lower rate of negative symptoms. The authors discuss implications of these findings for conceptualizing psychosis as a neurobiological syndrome.

  5. Brain radiation - discharge

    MedlinePlus

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  6. Personality Change Due to Traumatic Brain Injury in Children and Adolescents: Neurocognitive Correlates.

    PubMed

    Max, Jeffrey E; Wilde, Elisabeth A; Bigler, Erin D; Hanten, Gerri; Dennis, Maureen; Schachar, Russell J; Saunders, Ann E; Ewing-Cobbs, Linda; Chapman, Sandra B; Thompson, Wesley K; Yang, Tony T; Levin, Harvey S

    2015-01-01

    Personality change due to traumatic brain injury (PC) in children is an important psychiatric complication of injury and is a form of severe affective dysregulation. This study aimed to examine neurocognitive correlates of PC. The sample included 177 children 5-14 years old with traumatic brain injury who were enrolled from consecutive admissions to five trauma centers. Patients were followed up prospectively at baseline and at 6 months, and they were assessed with semistructured psychiatric interviews. Injury severity, socioeconomic status, and neurocognitive function (measures of attention, processing speed, verbal memory, IQ, verbal working memory, executive function, naming/reading, expressive language, motor speed, and motor inhibition) were assessed with standardized instruments. Unremitted PC was present in 26 (18%) of 141 participants assessed at 6 months postinjury. Attention, processing speed, verbal memory, IQ, and executive function were significantly associated with PC even after socioeconomic status, injury severity, and preinjury attention deficit hyperactivity disorder were controlled. These findings are a first step in characterizing concomitant cognitive impairments associated with PC. The results have implications beyond brain injury to potentially elucidate the neurocognitive symptom complex associated with mood instability regardless of etiology.

  7. Deficiency of p62/Sequestosome 1 causes hyperphagia due to leptin resistance in the brain.

    PubMed

    Harada, Harumi; Warabi, Eiji; Matsuki, Taizo; Yanagawa, Toru; Okada, Kosuke; Uwayama, Junya; Ikeda, Akira; Nakaso, Kazuhiro; Kirii, Kyoko; Noguchi, Noriko; Bukawa, Hiroki; Siow, Richard C M; Mann, Giovanni E; Shoda, Junichi; Ishii, Tetsuro; Sakurai, Takeshi

    2013-09-11

    The cytoplasmic regulatory protein p62 (Sequestosome 1/A170) is known to modulate various receptor-mediated intracellular signaling pathways. p62 deficiency was shown to result in mature-onset obesity in mice, but the mechanisms underlying this abnormality remained unclear. Here we report that hyperphagia due to central leptin resistance is the cause of obesity in p62(-/-) mice. We found that these mice show hyperphagia. Restriction of food to the amount eaten by wild-type mice prevented excess body weight gain and fat accumulation, suggesting that overfeeding is the primary cause of obesity in p62(-/-) mice. Brain-specific p62 deficiency caused mature-onset obesity to the same extent as in p62(-/-) mice, further supporting a neuronal mechanism as the major cause of obesity in these mice. Immunohistochemical analysis revealed that p62 is highly expressed in hypothalamic neurons, including POMC neurons in the arcuate nucleus. Central leptin resistance was observed even in young preobese p62(-/-) mice. We found a defect in intracellular distribution of the transcription factor Stat3, which is essential for the action of leptin, in p62(-/-) mice. These results indicate that brain p62 plays an important role in bodyweight control by modulating the central leptin-signaling pathway and that lack of p62 in the brain causes leptin resistance, leading to hyperphagia. Thus, p62 could be a clinical target for treating obesity and metabolic syndrome.

  8. Personality Change due to Traumatic Brain Injury in Children and Adolescents: Neurocognitive Correlates

    PubMed Central

    Wilde, Elisabeth A.; Bigler, Erin D.; Hanten, Gerri; Dennis, Maureen; Schachar, Russell J.; Saunders, Ann E.; Ewing-Cobbs, Linda; Chapman, Sandra B.; Thompson, Wesley K.; Yang, Tony T.; Levin, Harvey S.

    2015-01-01

    Personality Change due to traumatic brain injury (PC) in children is an important psychiatric complication of injury and is a form of severe affective dysregulation. The aim of the study was to examine neurocognitive correlates of PC. The sample included children (n=177) aged 5-14 years with traumatic brain injury from consecutive admissions to 5 trauma centers were followed prospectively at baseline and 6 months with semi-structured psychiatric interviews. Injury severity, socioeconomic status, and neurocognitive function (measures of attention, processing speed, verbal memory, IQ, verbal working memory, executive function, naming/reading, expressive language, motor speed, and motor inhibition) were assessed with standardized instruments. Unremitted PC was present in 26/141 (18%) participants assessed at 6 months post-injury. Attention, processing speed, verbal memory, IQ, and executive function, were significantly associated (p < .05) with PC even after socioeconomic status, injury severity, and pre-injury attention-deficit/hyperactivity disorder were controlled. These findings are a first step in characterizing concomitant cognitive impairments associated with PC. The results have implications beyond brain injury to potentially elucidate the neurocognitive symptom complex associated with mood instability regardless of etiology. PMID:26185905

  9. Brain abscess due to Cladophialophora bantiana: a review of 124 cases.

    PubMed

    Chakrabarti, Arunaloke; Kaur, Harsimran; Rudramurthy, Shivaprakash M; Appannanavar, Suma B; Patel, Atul; Mukherjee, Kanchan K; Ghosh, Anup; Ray, Ujjwayini

    2016-02-01

    Brain abscess caused by Cladophialophora bantiana is a rare disease associated with high mortality due to delay in diagnosis and absence of standardized therapy. We reviewed 124 culture proven C. bantiana brain abscess cases; 103 cases published in English literature during 1952 through 2014 and 21 unpublished cases from our reference center. The majority (57.3%) of the patients was from Asian countries especially from India (62/124, 50%). The diagnosis of the cases was delayed with mean duration 115 days after developing symptoms. The disease was nearly equally distributed in immunocompetent and immunosuppressed hosts but associated with significantly higher mortality (77.1%) in later group. Complete excision of brain lesion in immunocompetent host led to significantly better survival (43.7%). Though all commercially available antifungal drugs have been used in these patients, amphotericin B deoxycholate or lipid preparations were most commonly (62.83%) prescribed agent. None of the drugs used was found to be independently associated with improved outcome. In vitro antifungal susceptibility testing of 13 isolates of our center, demonstrated good activity to voriconazole, posaconazole, and itraconazole, but these triazoles were prescribed in only 29.2% patients. Increased awareness with early suspicion of the disease, and aggressive medical and surgical approach in treating these patients may improve the outcome. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Postoperative pectoral swelling after shoulder arthroscopy

    PubMed Central

    ERCIN, ERSIN; BILGILI, MUSTAFA GOKHAN; ONES, HALIL NADIR; KURAL, CEMAL

    2015-01-01

    Fluid extravasation is possibly the most common complication of shoulder arthroscopy. Shoulder arthroscopy can lead to major increases in the compartment pressure of adjacent muscles and this phenomenon is significant when an infusion pump is used. This article describes a case of pectoral swelling due to fluid extravasation after shoulder arthroscopy. A 24-year-old male underwent an arthroscopic Bankart repair for recurrent shoulder dislocation. The surgery was performed in the beach chair position and lasted two hours. At the end of the procedure, the patient was found to have left pectoral swelling. A chest radiography showed no abnormality. Pectoral swelling due to fluid extravasation after shoulder arthroscopy has not previously been documented. PMID:26889473

  11. Postoperative pectoral swelling after shoulder arthroscopy.

    PubMed

    Ercin, Ersin; Bilgili, Mustafa Gokhan; Ones, Halil Nadir; Kural, Cemal

    2015-01-01

    Fluid extravasation is possibly the most common complication of shoulder arthroscopy. Shoulder arthroscopy can lead to major increases in the compartment pressure of adjacent muscles and this phenomenon is significant when an infusion pump is used. This article describes a case of pectoral swelling due to fluid extravasation after shoulder arthroscopy. A 24-year-old male underwent an arthroscopic Bankart repair for recurrent shoulder dislocation. The surgery was performed in the beach chair position and lasted two hours. At the end of the procedure, the patient was found to have left pectoral swelling. A chest radiography showed no abnormality. Pectoral swelling due to fluid extravasation after shoulder arthroscopy has not previously been documented.

  12. [A case of a penetrating brain injury due to an explosion of a construction machine].

    PubMed

    Ibayashi, Kenji; Tsutsumi, Kazuo; Yoshikawa, Gakushi; Uno, Takeshi; Shimada, Shiko; Kawashima, Mariko; Koizumi, Satoshi; Ochiai, Yushi

    2012-05-01

    Penetrating brain injury caused by a high speed projectile is rather rare in Japan, known for its strict gun-control laws. We report a case of a 55-year-old male, who was transferred to our hospital with a foreign body in the brain due to penetrating head injury, which was caused by an explosion of a construction machine. Neurological examination demonstrated severe motor aphagia with no apparent motor paresis. The patient had a scalp laceration on his left forehead with exposed cerebral tissue and CSF leakage. Head CT scan and plain skull X-ray revealed a 20 mm×25 mm bolt which had penetrated due to the explosion of the machine. The anterior wall of the left frontal sinus was fractured resulting in dural laceration, and scattered bone fragments were seen along the trajectory of the bolt. Digital subtraction angiography showed no significant vascular injuries including superior sagittal sinus. We performed open surgery, and successfully removed the bolt along with the damaged frontal lobe. The patient had no infection or seizure after the surgery, and was transferred for further rehabilitation therapy. We performed a cosmetic cranioplasty six months later. Surgical debridement of the damaged cerebral tissue along the trajectory led to successful removal of the bolt with no further neurological deficit.

  13. Mitochondrial Swelling Induced by Glutathione

    PubMed Central

    Lehninger, Albert L.; Schneider, Marion

    1959-01-01

    Reduced glutathione, in concentrations approximating those occurring in intact rat liver, causes swelling of rat liver mitochondria in vitro which is different in kinetics and extent from that yielded by L-thyroxine. The effect is also given by cysteine, which is more active, and reduced coenzyme A, but not by L-ascorbate, cystine, or oxidized glutathione. The optimum pH is 6.5, whereas thyroxine-induced swelling is optimal at pH 7.5. The GSH-induced swelling is not inhibited by DNP or dicumarol, nor by high concentrations of sucrose, serum albumin, or polyvinylpyrrolidone, in contrast to thyroxine-induced swelling. ATP inhibits the GSH swelling, but ADP and AMP are ineffective. Mn-+ is a very potent inhibitor, but Mg++ is ineffective. Ethylenediaminetetraacetate is also an effective inhibitor of GSH-induced swelling. The respiratory inhibitors amytal and antimycin A do not inhibit the swelling action of GSH, but cyanide does; these findings are consistent with the view that the oxidation-reduction state of the respiratory chain between cytochrome c and oxygen is a determinant of GSH-induced swelling. Reversal of GSH-induced swelling by osmotic means or by ATP in KCl media could not be observed. Large losses of nucleotides and protein occur during the swelling by GSH, suggesting that the action is irreversible. The characteristically drastic swelling action of GSH could be prevented if L-thyroxine was also present in the medium. PMID:13630941

  14. Local CO2-induced swelling of shales

    NASA Astrophysics Data System (ADS)

    Pluymakers, Anne; Dysthe, Dag Kristian

    2017-04-01

    In heterogeneous shale rocks, CO2 adsorbs more strongly to organic matter than to the other components. CO2-induced swelling of organic matter has been shown in coal, which is pure carbon. The heterogeneity of the shale matrix makes an interesting case study. Can local swelling through adsorption of CO2 to organic matter induce strain in the surrounding shale matrix? Can fractures close due to CO2-induced swelling of clays and organic matter? We have developed a new generation of microfluidic high pressure cells (up to 100 bar), which can be used to study flow and adsorption phenomena at the microscale in natural geo-materials. The devices contain one transparent side and a shale sample on the other side. The shale used is the Pomeranian shale, extracted from 4 km depth in Poland. This formation is a potential target of a combined CO2-storage and gas extraction project. To answer the first question, we place the pressure cell under a Veeco NT1100 Interferometer, operated in Vertical Scanning Interferometry mode and equipped with a Through Transmissive Media objective. This allows for observation of local swelling or organic matter with nanometer vertical resolution and micrometer lateral resolution. We expose the sample to CO2 atmospheres at different pressures. Comparison of the interferometry data and using SEM-EDS maps plus optical microscopy delivers local swelling maps where we can distinguish swelling of different mineralogies. Preliminary results indicate minor local swelling of organic matter, where the total amount is both time- and pressure-dependent.

  15. Predictors of Personality Change Due to Traumatic Brain Injury in Children and Adolescents in the First Six Months after Injury.

    ERIC Educational Resources Information Center

    Max, Jeffrey E.; Levin, Harvey S.; Landis, Julie; Schachar, Russell; Saunders, Ann; Ewing-Cobbs, Linda; Chapman, Sandra B.; Dennis, Maureen

    2005-01-01

    Objective: To assess the phenomenology and predictive factors of personality change due to traumatic brain injury. Method: Children (N = 177), aged 5 to 14 years with traumatic brain injury from consecutive admissions to five trauma centers, were followed prospectively at baseline and 6 months with semistructured psychiatric interviews. Injury…

  16. Predictors of Personality Change Due to Traumatic Brain Injury in Children and Adolescents in the First Six Months after Injury.

    ERIC Educational Resources Information Center

    Max, Jeffrey E.; Levin, Harvey S.; Landis, Julie; Schachar, Russell; Saunders, Ann; Ewing-Cobbs, Linda; Chapman, Sandra B.; Dennis, Maureen

    2005-01-01

    Objective: To assess the phenomenology and predictive factors of personality change due to traumatic brain injury. Method: Children (N = 177), aged 5 to 14 years with traumatic brain injury from consecutive admissions to five trauma centers, were followed prospectively at baseline and 6 months with semistructured psychiatric interviews. Injury…

  17. Exposure to Surgery and Anesthesia After Concussion Due to Mild Traumatic Brain Injury.

    PubMed

    Abcejo, Arnoley S; Savica, Rodolfo; Lanier, William L; Pasternak, Jeffrey J

    2017-07-01

    To describe the epidemiology of surgical and anesthetic procedures in patients recently diagnosed as having a concussion due to mild traumatic brain injury. Study patients presented to a tertiary care center after a concussion due to mild traumatic brain injury from July 1, 2005, through June 30, 2015, and underwent a surgical procedure and anesthesia support under the direct or indirect care of a physician anesthesiologist. During the study period, 1038 patients met all the study inclusion criteria and subsequently received 1820 anesthetics. In this population of anesthetized patients, rates of diagnosed concussions due to sports injuries, falls, and assaults, but not motor vehicle accidents, increased during 2010-2011. Concussions were diagnosed in 965 patients (93%) within 1 week after injury. In the 552 patients who had surgery within 1 week after concussive injury, 29 (5%) had anesthesia and surgical procedures unrelated to their concussion-producing traumatic injury. The highest use of surgery occurred early after injury and most frequently required general anesthesia. Orthopedic and general surgical procedures accounted for 57% of procedures. Nine patients received 29 anesthetics before a concussion diagnosis, and all of these patients had been involved in motor vehicle accidents and received at least 1 anesthetic within 1 week of injury. Surgical and anesthesia use are common in patients after concussion. Clinicians should have increased awareness for concussion in patients who sustain a trauma and may need to take measures to avoid potentially injury-augmenting cerebral physiology in these patients. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  18. Effects of an alveolar recruitment maneuver on subdural pressure, brain swelling, and mean arterial pressure in patients undergoing supratentorial tumour resection: a randomized crossover study.

    PubMed

    Flexman, Alana M; Gooderham, Peter A; Griesdale, Donald E; Argue, Ruth; Toyota, Brian

    2017-06-01

    Although recruitment maneuvers have been advocated as part of a lung protective ventilation strategy, their effects on cerebral physiology during elective neurosurgery are unknown. Our objectives were to determine the effects of an alveolar recruitment maneuver on subdural pressure (SDP), brain relaxation score (BRS), and cerebral perfusion pressure among patients undergoing supratentorial tumour resection. In this prospective crossover study, patients scheduled for resection of a supratentorial brain tumour were randomized to undergo either a recruitment maneuver (30 cm of water for 30 sec) or a "sham" maneuver (5 cm of water for 30 sec), followed by the alternative intervention after a 90-sec equilibration period. Subdural pressure was measured through a dural perforation following opening of the cranium. Subdural pressure and mean arterial pressure (MAP) were recorded continuously. The blinded neurosurgeon provided a BRS at baseline and at the end of each intervention. During each treatment, the changes in SDP, BRS, and MAP were compared. Twenty-one patients underwent the study procedure. The increase in SDP was higher during the recruitment maneuver than during the sham maneuver (difference, 3.9 mmHg; 95% confidence interval [CI], 2.2 to 5.6; P < 0.001). Mean arterial pressure decreased further in the recruitment maneuver than in the sham maneuver (difference, -9.0 mmHg; 95% CI, -12.5 to -5.6; P < 0.001). Cerebral perfusion pressure decreased 14 mmHg (95% CI, 4 to 24) during the recruitment maneuver. The BRS did not change with either maneuver. Our results suggest that recruitment maneuvers increase subdural pressure and reduce cerebral perfusion pressure, although the clinical importance of these findings is thus far unknown. This trial was registered with ClinicalTrials.gov, NCT02093117.

  19. Swelling and Stress Relaxation in Portland Brownstone

    NASA Astrophysics Data System (ADS)

    Jimenez, I.; Scherer, G.

    2003-04-01

    Portland Brownstone (PB) is an arkose sandstone extensively used in the northeast-ern USA during the nineteenth century. This reddish-brown stone contains a fraction of swelling clays that are thought to contribute to its degradation upon cycles of wet-ting and drying. During drying events, contraction of the drying surface leads to stresses approaching the tensile strength of the stone. However, we have found that the magnitude of these stresses is limited by the ability of the stone to undergo stress relaxation. In this paper we describe novel methods to determine the magnitude of the stresses and the rate at which they develop and relax. We also discuss the influ-ence of surfactants on the magnitude of swelling and the rate of the stress relaxation of PB. The implications of our findings for the understanding of damage due to swelling of clays are discussed.

  20. [Pediatric traumatic brain injury due to civil gunshot wounds at a General Hospital in Cali, Colombia].

    PubMed

    Parrado Sánchez, L; Gómez, C; Valderrama Chaparro, J A; Beltrán Osorio, L D; Sierra Ruiz, M; Enríquez Marulanda, A; Lobato Polo, J

    2017-01-25

    Traumatic brain injury (TBI) due to gunshot-wounds (GSW) is a critical situation in the pediatric population. The aim of this study is to characterize TBI in this population since there are few reports that describe it especially in Colombia where its incidence is high, also to determine which were the main mortality predictor within our population. We conducted a retrospective cross-sectional study in which we reviewed pediatric medical records of patients that had consulted at the Fundacion Valle del Lili pediatric Emergency Room between January of 2011 and December of 2015 because of TBI due to GSW. A descriptive statistical analysis was performed. In our sample of 32 patients the average age was of 13.3 (SD ± 5.4) and with 75% male patients. In our sample the Glasgow Coma Scale (GCS) at entry was less than 8 in 59.38%, a 15.6% needed craniotomy and 81.2% were admitted to the Intensive Care Unit (ICU). Death occurred in 43.75% of cases. The following mortality predictors were obtained: GCS at entry, pupillary exam and light reflexes, ISS, Marshal Score, absence of basal cisterns and presence of subarachnoid hemorrhage in CT scan, and APACHE II. TBI due to GSW is a devastating entity, especially in the pediatric population, they are responsible of high mortality and disability rates. There were no significant findings regarding infection rates and the use of surgery as a preventive method, therefore there's a chance it might not be indicated.

  1. Marked potentiation of cell swelling by cytokines in ammonia-sensitized cultured astrocytes

    PubMed Central

    2010-01-01

    Background Brain edema leading to high intracranial pressure is a lethal complication of acute liver failure (ALF), which is believed to be cytotoxic due to swelling of astrocytes. In addition to the traditional view that elevated levels of blood and brain ammonia are involved in the mechanism of brain edema in ALF, emerging evidence suggests that inflammatory cytokines also contribute to this process. We earlier reported that treatment of astrocyte cultures with a pathophysiological concentration of ammonia (5 mM NH4Cl) resulted in the activation of nuclear factor-kappaB (NF-κB) and that inhibition of such activation diminished astrocyte swelling, suggesting a key role of NF-κB in the mechanism of ammonia-induced astrocyte swelling. Since cytokines are also well-known to activate NF-κB, this study examined for additive/synergistic effects of ammonia and cytokines in the activation of NF-κB and their role in astrocyte swelling. Methods Primary cultures of astrocytes were treated with ammonia and cytokines (TNF-α, IL-1, IL-6, IFN-γ, each at 10 ng/ml), individually or in combination, and cell volume was determined by the [3H]-O-methylglucose equilibration method. The effect of ammonia and cytokines on the activation of NF-κB was determined by immunoblots. Results Cell swelling was increased by ammonia (43%) and by cytokines (37%) at 24 h. Simultaneous co-treatment with cytokines and ammonia showed no additional swelling. By contrast, cultures pretreated with ammonia for 24 h and then exposed to cytokines for an additional 24 h, showed a marked increase in astrocyte swelling (129%). Treatment of cultures with ammonia or cytokines alone also activated NF-κB (80-130%), while co-treatment had no additive effect. However, in cultures pre-treated with ammonia for 24 h, cytokines induced a marked activation of NF-κB (428%). BAY 11-7082, an inhibitor of NF-κB, completely blocked the astrocyte swelling in cultures pre-treated with ammonia and followed by the

  2. Therapeutic effects of ellagic acid on memory, hippocampus electrophysiology deficits, and elevated TNF-α level in brain due to experimental traumatic brain injury.

    PubMed

    Mashhadizadeh, Shahram; Farbood, Yaghoub; Dianat, Mahin; Khodadadi, Ali; Sarkaki, Alireza

    2017-04-01

    Cognitive defects such as learning and memory impairment are amongst the most repetitious sequelae after sever and moderate traumatic brain injury (TBI). It was suggested that ellagic acid (EA), an innate phenol product, display neuroprotective properties against oxidative and inflammatory damages after brain injury. The object of the current study was therapeutic properties of EA on blood-brain barrier (BBB) interruption and elevated content of TNF-α in brain tissue followed by neurologic aftereffects, cognitive and brain electrophysiology deficits as outcomes of diffuse TBI in rat. TBI was induced by a 200 g weight falling by a 2-m height through a free-falling tube onto the head of anesthetized rat. TBI rats treated immediately after trauma with EA (100 mg/kg, IP) once every 8 hr until 48 hr later. Neurologic outcomes, passive avoidance task (PAT), hippocampal long-term potentiation (LTP), BBB permeability and content of TNF-α in brain tissue were evaluated. TBI induced significant impairments in neurological score, BBB function, PAT and hippocampal LTP in TBI+Veh group in compare with Sham+Veh (P<0.001). EA treatment decreased neurologic severity score (NSS), restored increased BBB permeability, cognitive and hippocampal LTP abnormalities, and elevated brain content of TNF-α due to TBI significantly (P<0.001). Our findings propose that EA can restore NSS, cognitive and LTP deficits and prevent brain inflammation may by restore BBB permeability as well as lowering brain content of TNF-α following TBI.

  3. Occurrence of spontaneous and audiogenic seizures following global brain ischaemia due to cardiac arrest.

    PubMed

    Ułamek-Kozioł, Marzena; Kocki, Janusz; Bogucka-Kocka, Anna; Januszewski, Sławomir; Czuczwar, Stanisław J; Pluta, Ryszard

    2015-01-01

    Transient cardiac arrest due to cardiac vessel bundle occlusion was used to produce a rat model of spontaneous and audiogenic seizures. Among the rats, spontaneous seizures were present in 64%, and audiogenic seizures could be evoked in 86%, during two weeks of survival after cardiac arrest, by exposure to a loud sound produced by rattling keys, beginning one day after the post-ischaemic injury. Data from literature suggested a key role for GABA-ergic system widespread dysfunction especially in the hippocampus in post-cardiac arrest onset of audiogenic seizures. Reduced GABA inhibition in the hippocampus seems responsible for audiogenic seizures following cardiac arrest. In summary it may be considered that the occurrence of audiogenic seizures following cardiac arrest is determined not only by a neuronal loss, especially in the hippocampus, but also by a condition of synapse modification by a regenerative phenomenon. Data from our study clearly indicate that global brain ischaemia due to cardiac arrest may induce the susceptibility to spontaneous and audiogenic seizures, but this effect is transient.

  4. Neuronal and glial alterations due to focal cortical hypoxia induced by direct cobalt chloride (CoCl2) brain injection.

    PubMed

    Caltana, Laura; Merelli, Amalia; Lazarowski, Alberto; Brusco, Alicia

    2009-05-01

    Ischemic brain injury is a dynamic process that involves oxidative stress, inflammation, and cell death, as well as activation of endogenous adaptive and regenerative mechanisms depending on activation of transcription factors such as hypoxia inducible factor 1-alpha (HIF-1alpha). Because CoCl2 activates HIF-1alpha, we described a new focal-hypoxia model by direct intracerebral CoCl2 injection. Adult male Wistar rats were intracerebrally injected with CoCl2 (2 microl-50 mM), in frontoparietal cortex of right hemisphere, and saline (2 microl) in the contralateral hemisphere. In slides of fixed brains at 1, 6, 9, 24 h or 5 day after treatment, TTC, histochemistry (toluidine blue, Hoescht-33342, TUNEL), immunostaining (HIF-1alpha, GFAP), Lycopersicon esculentum lectin staining, and electron microscopy (EM) were performed. Immediately after 1 h post CoCl2 injection, HIF-1alpha stabilization and neuronal nuclear shrinkage and cromathin condensation were observed by immunostaining and EM, respectively. Neuronal apoptotic nuclear morphology and GFAP immunoreactivity and lectin maximal reactivity were detected during 6-9 h. Ultrastructural alterations of morphology included edematous perinuclear cytoplasm, organelles and endoplasmic reticulum (RE) enlargement, mitochondrial swelling with increased matrix density, and deposits of electron-dense material. Neurons showed particular nuclear indentations. Astrocytes and oligodendrocytes presented alterations in both nuclei and RE with dilated lumen and altered mitochondrias, and all these ultrastructural changes became detectable at day 5. CoCl2 cortical injection mimics focal brain ischemia, inducing neuronal death and glial activation. This model brings the opportunity to develop focal ischemia in selected brain areas to study their functional consequences and potential pharmacological therapies for in vivo models of stroke.

  5. Stress Singularities in Swelling Soft Solids

    NASA Astrophysics Data System (ADS)

    Goriely, Alain; Weickenmeier, Johannes; Kuhl, Ellen

    2016-09-01

    When a swelling soft solid is rigidly constrained on all sides except for a circular opening, it will bulge out to expand as observed during decompressive craniectomy, a surgical procedure used to reduce stresses in swollen brains. While the elastic energy of the solid decreases throughout this process, large stresses develop close to the opening. At the point of contact, the stresses exhibit a singularity similar to the ones found in the classic punch indentation problem. Here, we study the stresses generated by swelling and the evolution of the bulging shape associated with this process. We also consider the possibility of damage triggered by zones of either high shear stresses or high fiber stretches.

  6. Brain-computer interface controlled functional electrical stimulation device for foot drop due to stroke.

    PubMed

    Do, An H; Wang, Po T; King, Christine E; Schombs, Andrew; Cramer, Steven C; Nenadic, Zoran

    2012-01-01

    Gait impairment due to foot drop is a common outcome of stroke, and current physiotherapy provides only limited restoration of gait function. Gait function can also be aided by orthoses, but these devices may be cumbersome and their benefits disappear upon removal. Hence, new neuro-rehabilitative therapies are being sought to generate permanent improvements in motor function beyond those of conventional physiotherapies through positive neural plasticity processes. Here, the authors describe an electroencephalogram (EEG) based brain-computer interface (BCI) controlled functional electrical stimulation (FES) system that enabled a stroke subject with foot drop to re-establish foot dorsiflexion. To this end, a prediction model was generated from EEG data collected as the subject alternated between periods of idling and attempted foot dorsiflexion. This prediction model was then used to classify online EEG data into either "idling" or "dorsiflexion" states, and this information was subsequently used to control an FES device to elicit effective foot dorsiflexion. The performance of the system was assessed in online sessions, where the subject was prompted by a computer to alternate between periods of idling and dorsiflexion. The subject demonstrated purposeful operation of the BCI-FES system, with an average cross-correlation between instructional cues and BCI-FES response of 0.60 over 3 sessions. In addition, analysis of the prediction model indicated that non-classical brain areas were activated in the process, suggesting post-stroke cortical re-organization. In the future, these systems may be explored as a potential therapeutic tool that can help promote positive plasticity and neural repair in chronic stroke patients.

  7. Post-mortem Findings in Huntington’s Deep Brain Stimulation: A Moving Target Due to Atrophy

    PubMed Central

    Vedam-Mai, Vinata; Martinez-Ramirez, Daniel; Hilliard, Justin D.; Carbunaru, Samuel; Yachnis, Anthony T.; Bloom, Joshua; Keeling, Peyton; Awe, Lisa; Foote, Kelly D.; Okun, Michael S.

    2016-01-01

    Background Deep brain stimulation (DBS) has been shown to be effective for Parkinson’s disease, essential tremor, and primary dystonia. However, mixed results have been reported in Huntington’s disease (HD). Case Report A single case of HD DBS was identified from the University of Florida DBS Brain Tissue Network. The clinical presentation, evolution, surgical planning, DBS parameters, clinical outcomes, and brain pathological changes are summarized. Discussion This case of HD DBS revealed that chorea may improve and be sustained. Minimal histopathological changes were noted around the DBS leads. Severe atrophy due to HD likely changed the DBS lead position relative to the internal capsule. PMID:27127722

  8. Evaluation of linear registration algorithms for brain SPECT and the errors due to hypoperfusion lesions.

    PubMed

    Radau, P E; Slomka, P J; Julin, P; Svensson, L; Wahlund, L O

    2001-08-01

    The semiquantitative analysis of perfusion single-photon emission computed tomography (SPECT) images requires a reproducible, objective method. Automated spatial standardization (registration) of images is a prerequisite to this goal. A source of registration error is the presence of hypoperfusion defects, which was evaluated in this study with simulated lesions. The brain perfusion images measured by 99mTc-HMPAO SPECT from 21 patients with probable Alzheimer's disease and 35 control subjects were retrospectively analyzed. An automatic segmentation method was developed to remove external activity. Three registration methods, robust least squares, normalized mutual information (NMI), and count difference were implemented and the effects of simulated defects were compared. The tested registration methods required segmentation of the cerebrum from external activity, and the automatic and manual methods differed by a three-dimensional displacement of 1.4+/-1.1 mm. NMI registration proved to be least adversely effected by simulated defects with 3 mm average displacement caused by severe defects. The error in quantifying the patient-template parietal ratio due to misregistration was 2.0% for large defects (70% hypoperfusion) and 0.5% for smaller defects (85% hypoperfusion).

  9. Olanzapine and Betamethasone Are Effective for the Treatment of Nausea and Vomiting due to Metastatic Brain Tumors of Rectal Cancer

    PubMed Central

    Suzuki, M.; Komuro, K.; Ohara, K.

    2014-01-01

    Brain lesions originating from metastasis of colorectal cancer represent 3–5% of all brain metastases and are relatively rare. Of all distant metastases of colorectal cancer, those to the liver are detected in 22–29% of cases, while those to the lungs are detected in 8–18% of cases. In contrast, brain metastasis is quite rare, with a reported incidence ranging from 0.4 to 1.8%. Treatments for metastatic brain tumors include surgery, radiotherapy, chemotherapy and supportive care with steroids, etc. Untreated patients exhibit a median survival of only approximately 1 month. The choice of treatment for brain metastasis depends on the number of lesions, the patient's general condition, nerve findings and presence of other metastatic lesions. We herein report the case of a 78-year-old male who presented with brain metastases originating from rectal carcinoma. He suffered from nausea, vomiting, anorexia and vertigo during body movement. He received antiemetics, glycerol and whole brain radiation therapy; however, these treatments proved ineffective. Olanzapine therapy was started at a dose of 1.25 mg every night. The persistent nausea disappeared the next day, and the frequency of vomiting subsequently decreased. The patient was able to consume solid food. Olanzapine is an antipsychotic that has recently been used as palliative therapy for refractory nausea and vomiting in patients receiving chemotherapy. We consider that olanzapine was helpful as a means of supportive care for the treatment of nausea and vomiting due to brain metastasis. PMID:24574944

  10. Psychological and adjustment problems due to acquired brain lesions in pre-school-aged patients.

    PubMed

    Pastore, Valentina; Colombo, Katia; Villa, Federica; Galbiati, Susanna; Adduci, Annarita; Poggi, Geraldina; Massimino, Maura; Recla, Monica; Liscio, Mariarosaria; Strazzer, Sandra

    2013-06-01

    To describe and compare psychological, behavioural and adjustment problems in pre-school patients with acquired brain lesions of different aetiology. Three groups of patients with acquired brain lesions (14 patients post-TBI, 18 brain tumour survivors and 23 patients with vascular or infectious brain lesions), ranging in age between 24-47 months, received a psychological evaluation, including the Child Behavior Checklist for Ages 2-3 (CBCL) and the Vineland Adaptive Behavior Scales (VABS). About half of the total sample (47.2%) showed psychological and behavioural problems. Difficulties vary according to the aetiology of the brain lesions. Brain tumour survivors showed more marked internalizing problems, whereas children with vascular or infectious brain lesions scored higher on the CBCL externalizing scales. Children with traumatic brain injury reported intermediate scores on most of the CBCL scales. Psychological and behavioural difficulties are very common, not only among school-aged children and adolescents, but also among pre-schoolers with acquired brain lesions. The relevance and the impact of these difficulties must necessarily be considered when developing psychological treatment and rehabilitation plans and planning for social re-entry.

  11. The costs of traumatic brain injury due to motorcycle accidents in Hanoi, Vietnam

    PubMed Central

    Hoang, Hanh TM; Pham, Tran L; Vo, Thuy TN; Nguyen, Phuong K; Doran, Christopher M; Hill, Peter S

    2008-01-01

    Background Road traffic accidents are the leading cause of fatal and non-fatal injuries in Vietnam. The purpose of this study is to estimate the costs, in the first year post-injury, of non-fatal traumatic brain injury (TBI) in motorcycle users not wearing helmets in Hanoi, Vietnam. The costs are calculated from the perspective of the injured patients and their families, and include quantification of direct, indirect and intangible costs, using years lost due to disability as a proxy. Methods The study was a retrospective cross-sectional study. Data on treatment and rehabilitation costs, employment and support were obtained from patients and their families using a structured questionnaire and The European Quality of Life instrument (EQ6D). Results Thirty-five patients and their families were interviewed. On average, patients with severe, moderate and minor TBI incurred direct costs at USD 2,365, USD 1,390 and USD 849, with time lost for normal activities averaging 54 weeks, 26 weeks and 17 weeks and years lived with disability (YLD) of 0.46, 0.25 and 0.15 year, respectively. Conclusion All three component costs of TBI were high; the direct cost accounted for the largest proportion, with costs rising with the severity of TBI. The results suggest that the burden of TBI can be catastrophic for families because of high direct costs, significant time off work for patients and caregivers, and impact on health-related quality of life. Further research is warranted to explore the actual social and economic benefits of mandatory helmet use. PMID:18718026

  12. Computational Morphometry for Detecting Changes in Brain Structure Due to Development, Aging, Learning, Disease and Evolution

    PubMed Central

    Mietchen, Daniel; Gaser, Christian

    2009-01-01

    The brain, like any living tissue, is constantly changing in response to genetic and environmental cues and their interaction, leading to changes in brain function and structure, many of which are now in reach of neuroimaging techniques. Computational morphometry on the basis of Magnetic Resonance (MR) images has become the method of choice for studying macroscopic changes of brain structure across time scales. Thanks to computational advances and sophisticated study designs, both the minimal extent of change necessary for detection and, consequently, the minimal periods over which such changes can be detected have been reduced considerably during the last few years. On the other hand, the growing availability of MR images of more and more diverse brain populations also allows more detailed inferences about brain changes that occur over larger time scales, way beyond the duration of an average research project. On this basis, a whole range of issues concerning the structures and functions of the brain are now becoming addressable, thereby providing ample challenges and opportunities for further contributions from neuroinformatics to our understanding of the brain and how it changes over a lifetime and in the course of evolution. PMID:19707517

  13. Breast - premenstrual tenderness and swelling

    MedlinePlus

    ... breasts occurs during the second half of the menstrual cycle. Considerations Symptoms of premenstrual breast tenderness may range ... pain, and tenderness. Causes Hormone changes during the menstrual cycle likely lead to breast swelling. More estrogen is ...

  14. Different approaches to modeling analysis of mitochondrial swelling.

    PubMed

    Javadov, Sabzali; Chapa-Dubocq, Xavier; Makarov, Vladimir

    2017-08-10

    Mitochondria are critical players involved in both cell life and death through multiple pathways. Structural integrity, metabolism and function of mitochondria are regulated by matrix volume due to physiological changes of ion homeostasis in cellular cytoplasm and mitochondria. Ca(2+) and K(+) presumably play a critical role in physiological and pathological swelling of mitochondria when increased uptake (influx)/decreased release (efflux) of these ions enhances osmotic pressure accompanied by high water accumulation in the matrix. Changes in the matrix volume in the physiological range have a stimulatory effect on electron transfer chain and oxidative phosphorylation to satisfy metabolic requirements of the cell. However, excessive matrix swelling associated with the sustained opening of mitochondrial permeability transition pores (PTP) and other PTP-independent mechanisms compromises mitochondrial function and integrity leading to cell death. The mechanisms of transition from reversible (physiological) to irreversible (pathological) swelling of mitochondria remain unknown. Mitochondrial swelling is involved in the pathogenesis of many human diseases such as neurodegenerative and cardiovascular diseases. Therefore, modeling analysis of the swelling process is important for understanding the mechanisms of cell dysfunction. This review attempts to describe the role of mitochondrial swelling in cell life and death and the main mechanisms involved in the maintenance of ion homeostasis and swelling. The review also summarizes and discusses different kinetic models and approaches that can be useful for the development of new models for better simulation and prediction of in vivo mitochondrial swelling. Copyright © 2017 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  15. Ocean swell within the kinetic equation for water waves

    NASA Astrophysics Data System (ADS)

    Badulin, Sergei I.; Zakharov, Vladimir E.

    2017-06-01

    Results of extensive simulations of swell evolution within the duration-limited setup for the kinetic Hasselmann equation for long durations of up to 2 × 106 s are presented. Basic solutions of the theory of weak turbulence, the so-called Kolmogorov-Zakharov solutions, are shown to be relevant to the results of the simulations. Features of self-similarity of wave spectra are detailed and their impact on methods of ocean swell monitoring is discussed. Essential drop in wave energy (wave height) due to wave-wave interactions is found at the initial stages of swell evolution (on the order of 1000 km for typical parameters of the ocean swell). At longer times, wave-wave interactions are responsible for a universal angular distribution of wave spectra in a wide range of initial conditions. Weak power-law attenuation of swell within the Hasselmann equation is not consistent with results of ocean swell tracking from satellite altimetry and SAR (synthetic aperture radar) data. At the same time, the relatively fast weakening of wave-wave interactions makes the swell evolution sensitive to other effects. In particular, as shown, coupling with locally generated wind waves can force the swell to grow in relatively light winds.

  16. [The efficacy of botulinum toxin therapy in patients with upper limb spasticity due to traumatic brain injury].

    PubMed

    Akulov, M A; Hat'kova, S E; Mokienko, O A; Orlova, O R; Usachev, D Yu; Zakharov, V O; Orlova, A S; Tomskiy, A A

    Spasticity is a type of muscle hyperactivity that occurs in patients after focal lesions of the Central nervous system due to various diseases: stroke, traumatic brain injury or spinal cord injury, neurosurgical intervention, as well as multiple sclerosis and other diseases of the Central nervous system and is the most disability manifestation of the syndrome of upper motor neuron (UMNS). Focal spasticity of the upper limb requires a complex treatment. Botulinum toxin therapy is an effective treatment for focal/multifocal spasticity in reducing muscle tone and improving function with the highest level of evidence according to the latest American and European guidelines for treatment of spasticity. There are many publications devoted to BTA use in post-stroke patients. This article provides a review of the BTA use in patients with the upper limb spasticity due to severe traumatic brain injury. Some local data on the BTA efficacy in the cohort of patients with traumatic brain injury are also presented.

  17. Identification of lateralized compensatory neural activities within the social brain due to autism spectrum disorder in adolescent males.

    PubMed

    Subbaraju, Vigneshwaran; Sundaram, Suresh; Narasimhan, Sundararajan

    2017-06-29

    Socio-behavioral impairments are important characteristics of autism spectrum disorders (ASD) and MRI-based studies are pursued to identify a neurobiological basis behind these conditions. This paper presents an MRI-based study undertaken to (i) identify the differences in brain activities due to ASD, (ii) verify whether such differences exist within the 'social brain' circuit which is hypothesized to be responsible for social functions, and (iii) uncover potential compensatory mechanisms within the identified differences in brain activities. In this study, a whole-brain voxel-wise analysis is performed using resting-state fMRI data from 598 adolescent males, that is openly available from the ABIDE consortium. A new method is developed, which can (i) extract the discriminative brain activities, that provide high separability between the blood oxygenation time-series signals from ASD and neurotypical populations, (ii) select the activities that are relevant to ASD by evaluating the correlation between the separability and traditional severity scores, and (iii) map the spatial pattern of regions responsible for generating the discriminative activities. The results show that the most discriminative brain activities occur within a subset of the social brain that is involved with affective aspects of social processing, thereby supporting the idea of the social brain and also its fractionalization in ASD. Further, it has also been found that the diminished activities in the posterior cingulate area are potentially compensated by enhanced activities in the ventromedial prefrontal and anterior temporal areas within the social brain. Hemispherical lateralization is also observed on such compensatory activities. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. Swelling/deswelling of Toroidal Hydrogels

    NASA Astrophysics Data System (ADS)

    Chang, Ya-Wen; Dimitriyev, Michael; Marquez, Samantha; Goldbart, Paul; Fernandez-Nieves, Alberto

    2014-03-01

    Swelling/deswelling of hydrogel spheres proceeds with the increase/decrease of particle radius that corresponds to the change in overall volume. When the hydrogel has a toroidal geometry, which is characterized by two principal radii -radius from the center of the donut hole to the center of the tube, and the tube radius, it is not obvious how swelling proceeds. We prepare thermo-sensitive poly(N-isopropylacrylamide) pNIPAM toroidal gel particles of different aspect ratios. At equilibrium deswelling, i.e., slow heating rate, we find that the aspect ratio remains constant for both fat and thin tori. This is explained by linear elasticity. On the other hand, when the heating rate is sufficiently high, the toroid buckles due to the presence of a water-impermeable skin layer that develops in the initial deswelling stages. Acknowledgement: We thank Dr. Manuel Marquez, YNano LLC for financial support

  19. Interventions for dysarthria due to stroke and other adult-acquired, non-progressive brain injury.

    PubMed

    Mitchell, Claire; Bowen, Audrey; Tyson, Sarah; Butterfint, Zoe; Conroy, Paul

    2017-01-25

    Dysarthria is an acquired speech disorder following neurological injury that reduces intelligibility of speech due to weak, imprecise, slow and/or unco-ordinated muscle control. The impact of dysarthria goes beyond communication and affects psychosocial functioning. This is an update of a review previously published in 2005. The scope has been broadened to include additional interventions, and the title amended accordingly. To assess the effects of interventions to improve dysarthric speech following stroke and other non-progressive adult-acquired brain injury such as trauma, infection, tumour and surgery. We searched the Cochrane Stroke Group Trials Register (May 2016), CENTRAL (Cochrane Library 2016, Issue 4), MEDLINE, Embase, and CINAHL on 6 May 2016. We also searched Linguistics and Language Behavioral Abstracts (LLBA) (1976 to November 2016) and PsycINFO (1800 to September 2016). To identify further published, unpublished and ongoing trials, we searched major trials registers: WHO ICTRP, the ISRCTN registry, and ClinicalTrials.gov. We also handsearched the reference lists of relevant articles and contacted academic institutions and other researchers regarding other published, unpublished or ongoing trials. We did not impose any language restrictions. We selected randomised controlled trials (RCTs) comparing dysarthria interventions with 1) no intervention, 2) another intervention for dysarthria (this intervention may differ in methodology, timing of delivery, duration, frequency or theory), or 3) an attention control. Three review authors selected trials for inclusion, extracted data, and assessed risk of bias. We attempted to contact study authors for clarification and missing data as required. We calculated standardised mean difference (SMD) and 95% confidence interval (CI), using a random-effects model, and performed sensitivity analyses to assess the influence of methodological quality. We planned to conduct subgroup analyses for underlying clinical

  20. Impact of metal artefacts due to EEG electrodes in brain PET/CT imaging.

    PubMed

    Lemmens, Catherine; Montandon, Marie-Louise; Nuyts, Johan; Ratib, Osman; Dupont, Patrick; Zaidi, Habib

    2008-08-21

    The goal of this study is to investigate the impact of electroencephalogram (EEG) electrodes on the visual quality and quantification of (18)F-FDG PET images in neurological PET/CT examinations. For this purpose, the scans of 20 epilepsy patients with EEG monitoring were used. The CT data were reconstructed with filtered backprojection (FBP) and with a metal artefact reduction (MAR) algorithm. Both data sets were used for CT-based attenuation correction (AC) of the PET data. Also, a calculated AC (CALC) technique was considered. A volume of interest (VOI)-based analysis and a voxel-based quantitative analysis were performed to compare the different AC methods. Images were also evaluated visually by two observers. It was shown with simulations and phantom measurements that from the considered AC methods, the MAR-AC can be used as the reference in this setting. The visual assessment of PET images showed local hot spots outside the brain corresponding to the locations of the electrodes when using FBP-AC. In the brain, no abnormalities were observed. The quantitative analysis showed a very good correlation between PET-FBP-AC and PET-MAR-AC, with a statistically significant positive bias in the PET-FBP-AC images of about 5-7% in most brain voxels. There was also good correlation between PET-CALC-AC and PET-MAR-AC, but in the PET-CALC-AC images, regions with both a significant positive and negative bias were observed. EEG electrodes give rise to local hot spots outside the brain and a positive quantification bias in the brain. However, when diagnosis is made by mere visual assessment, the presence of EEG electrodes does not seem to alter the diagnosis. When quantification is performed, the bias becomes an issue especially when comparing brain images with and without EEG monitoring.

  1. Impact of metal artefacts due to EEG electrodes in brain PET/CT imaging

    NASA Astrophysics Data System (ADS)

    Lemmens, Catherine; Montandon, Marie-Louise; Nuyts, Johan; Ratib, Osman; Dupont, Patrick; Zaidi, Habib

    2008-08-01

    The goal of this study is to investigate the impact of electroencephalogram (EEG) electrodes on the visual quality and quantification of 18F-FDG PET images in neurological PET/CT examinations. For this purpose, the scans of 20 epilepsy patients with EEG monitoring were used. The CT data were reconstructed with filtered backprojection (FBP) and with a metal artefact reduction (MAR) algorithm. Both data sets were used for CT-based attenuation correction (AC) of the PET data. Also, a calculated AC (CALC) technique was considered. A volume of interest (VOI)-based analysis and a voxel-based quantitative analysis were performed to compare the different AC methods. Images were also evaluated visually by two observers. It was shown with simulations and phantom measurements that from the considered AC methods, the MAR-AC can be used as the reference in this setting. The visual assessment of PET images showed local hot spots outside the brain corresponding to the locations of the electrodes when using FBP-AC. In the brain, no abnormalities were observed. The quantitative analysis showed a very good correlation between PET-FBP-AC and PET-MAR-AC, with a statistically significant positive bias in the PET-FBP-AC images of about 5-7% in most brain voxels. There was also good correlation between PET-CALC-AC and PET-MAR-AC, but in the PET-CALC-AC images, regions with both a significant positive and negative bias were observed. EEG electrodes give rise to local hot spots outside the brain and a positive quantification bias in the brain. However, when diagnosis is made by mere visual assessment, the presence of EEG electrodes does not seem to alter the diagnosis. When quantification is performed, the bias becomes an issue especially when comparing brain images with and without EEG monitoring.

  2. Hyperhidrosis due to deep brain stimulation in a patient with essential tremor. Case report.

    PubMed

    Diamond, Alan; Kenney, Christopher; Almaguer, Michael; Jankovic, Joseph

    2007-11-01

    The authors present a unique case of hyperhidrosis as a side effect of a misplaced deep brain stimulation (DBS) electrode near the ventrointermedius (Vim) nucleus in a patient with essential tremor. Magnetic resonance imaging of the brain showed electrode placement in the left anterior thalamus traversing the hypothalamus. High-frequency electrical stimulation possibly resulted in unilateral activation of the efferent sympathetic pathways in the zona incerta. Although a rare complication, hypothalamic dysfunction may occur as a stimulation-related side effect of Vim-DBS.

  3. Congenital osteolytic dural fibrosarcoma presenting as a scalp swelling.

    PubMed

    Brohi, Shams Raza; Dilber, Muzamil

    2012-08-01

    An extremely rare case of congenital dural fibrosarcoma is reported in a 2 months old child who presented with scalp swelling since birth. CT scan revealed an osteolytic lesion compressing the underlying atrophic brain. Tumour was completely excised and duroplasty was done with a patch graft. Postoperative CSF leak was managed with aspirations and lumbar puncture.

  4. Speech and language therapy for dysarthria due to non-progressive brain damage.

    PubMed

    Sellars, C; Hughes, T; Langhorne, P

    2001-01-01

    Dysarthria is a common sequel of non-progressive brain damage (typically stroke and traumatic brain damage). Impairment-based therapy and a wide variety of compensatory management strategies are undertaken by speech and language therapists with this patient population. To determine the efficacy of speech and language therapy interventions for adults with dysarthria following non-progressive brain damage. This review has drawn on the search strategies developed for the following Cochrane Groups as a whole: Stroke, Injuries, and Infectious Diseases. Relevant trials were identified in the Specialised Registers of Controlled Trials (see Review Group Details for more information). We also searched the trials register of the Cochrane Rehabilitation and Related Therapies Field. The Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, PsycLIT, and Linguistics and Language Behavior Abstracts were electronically searched. Hand-searching of The International Journal of Language and Communication Disorders and of reference lists from relevant articles and conference proceedings was also undertaken. Colleagues were approached to identify other possible published and unpublished studies. Date of most recent searches: May 2000. Unconfounded randomised controlled trials. One reviewer assessed trial quality. Two co-reviewers were available to examine any potential trials for possible inclusion in the review. No trials of the required standard were identified. There is no evidence of the quality required by this review to support or refute the effectiveness of Speech and Language Therapy interventions for dysarthria following non-progressive brain damage. There is an urgent need for good quality research in this area.

  5. Speech and language therapy for dysarthria due to nonprogressive brain damage: a systematic Cochrane review.

    PubMed

    Sellars, Cameron; Hughes, Thomas; Langhorne, Peter

    2002-02-01

    Dysarthria is a common sequel of nonprogressive brain damage (typically stroke and traumatic brain damage). Impairment-based therapy and a wide variety of compensatory management strategies are undertaken by speech and language therapists with this patient population. To determine the efficacy of speech and language therapy interventions for adults with dysarthria following nonprogressive brain damage. Systematic review. This review has drawn on the search strategies developed for the following Cochrane Groups as a whole: Stroke, Injuries, and Infectious Diseases. Relevant trials were identified in the Specialised Registers of Controlled Trials. We also searched the trials register of the Cochrane Rehabilitation and Related Therapies Field. The Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, PsycLIT, and Linguistics and Language Behavior Abstracts were electronically searched. Hand-searching of the International Journal of Language and Communication Disorders and of reference lists from relevant articles and conference proceedings was also undertaken. Colleagues were approached to identify other possible published and unpublished studies. Unconfounded randomized controlled trials. One reviewer assessed trial quality. Two co-reviewers were available to examine any potential trials for possible inclusion in the review. No trials of the required standard were identified. There is no evidence of the quality required by this review to support or refute the effectiveness of speech and language therapy interventions for dysarthria following nonprogressive brain damage. There is an urgent need for good quality research in this area.

  6. Kelussia odoratissima Mozaff attenuates thromboembolic brain injury, possibly due to its Z-ligustilide content.

    PubMed

    Barzegar-Fallah, Niloofar; Baery, Nasrin; Soleymankhani, Majid; Malekmohammadi, Nafiseh; Alimoradi, Houman; Parsa, Abdolhamid; Barzegar-Fallah, Anita

    2016-01-01

    Essential oil (EO) of Kelussia odoratissima Mozaff, whose main composition is Z-ligustilide, has been shown to have strong antioxidant and anti-inflammatory effects and potent neuroprotective properties. This study examined whether or not the EO could ameliorate brain damage and behavioural dysfunction in a thromboembolic model of stroke in rats and compare its effects to that of the purified Z-ligustilide. Stroke was induced in rats by middle cerebral artery occlusion using an autologous pre-formed clot. EO (10 mg kg(-1) and 45 mg kg(-1)) and Z-ligustilide (20 mg kg(-1)) were injected intraperitoneally 1 h prior to embolization. Behavioural scores, infarct size and brain oedema, as well as the level of tumour necrosis factor-alpha (TNF-α), malondialdehyde, glutathione, catalase and superoxide dismutase activity were determined in the ipsilateral cortex 24 hours following stroke induction. EO (45 mg kg(-1)), statistically similar to Z-ligustilide (20 mg kg(-1)), curtailed brain infarction and oedema, improved behavioural scores and prevented enhanced oxidative stress and TNF-α level in the ischaemic brain tissues. The findings provide the first evidence of effectiveness of the extract in a thromboembolic model of stroke, whose action can be mediated, at least in part, by the antioxidative and anti-inflammatory mechanisms.

  7. Low-frequency dielectric dispersion of brain tissue due to electrically long neurites

    NASA Astrophysics Data System (ADS)

    Monai, Hiromu; Inoue, Masashi; Miyakawa, Hiroyoshi; Aonishi, Toru

    2012-12-01

    The dielectric properties of brain tissue are important for understanding how neural activity is related to local field potentials and electroencephalograms. It is known that the permittivity of brain tissue exhibits strong frequency dependence (dispersion) and that the permittivity is very large in the low-frequency region. However, little is known with regard to the cause of the large permittivity in the low-frequency region. Here, we postulate that the dielectric properties of brain tissue can be partially accounted for by assuming that neurites are of sufficient length to be “electrically long.” To test this idea, we consider a model in which a neurite is treated as a long, narrow body, and it is subjected to a stimulus created by electrodes situated in the region external to it. With regard to this electric stimulus, the neurite can be treated as a passive cable. Assuming adequate symmetry so that the tissue packed with multiple cables is equivalent to an isolated system consisting of a single cable and a surrounding extracellular resistive medium, we analytically calculate the extracellular potential of the tissue in response to such an externally created alternating-current electric field using a Green's function that we obtained previously. Our results show that brain tissue modeled by such a cable existing within a purely resistive extracellular medium exhibits a large effective permittivity in the low-frequency region. Moreover, we obtain results suggesting that an extremely large low-frequency permittivity can coexist with weak low-pass filter characteristics in brain tissue.

  8. Non-isothermal extrudate swell

    NASA Astrophysics Data System (ADS)

    Konaganti, Vinod Kumar; Derakhshandeh, Maziar; Ebrahimi, Marzieh; Mitsoulis, Evan; Hatzikiriakos, Savvas G.

    2016-12-01

    The non-isothermal extrudate swell of a high molecular weight high-density polyethylene (HDPE) in long capillary and slit dies is studied numerically (ANSYS POLYFLOW®) using an integral K-BKZ constitutive model including crystallization kinetics, determined experimentally. The Nakamura model is used for crystallization of the HDPE, where the crystallization rate parameter is evaluated by using the well-known Ziabicki equation. This non-isothermal extrudate swell phenomenon is simulated using the pseudo-time integral K-BKZ model with the Wagner damping function along with the differential form of the Nakamura model to account for the crystallization of the extrudate. The swell measurements were carried out under non-isothermal conditions by extruding the polymer melt at 200 °C through long capillary and slit dies to ambient air at 25 °C, 110 °C, and 200 °C. The numerical results are found to be in excellent agreement with experimental observations.

  9. Neonatal neurobehavior and diffusion MRI changes in brain reorganization due to intrauterine growth restriction in a rabbit model.

    PubMed

    Eixarch, Elisenda; Batalle, Dafnis; Illa, Miriam; Muñoz-Moreno, Emma; Arbat-Plana, Ariadna; Amat-Roldan, Ivan; Figueras, Francesc; Gratacos, Eduard

    2012-01-01

    Intrauterine growth restriction (IUGR) affects 5-10% of all newborns and is associated with a high risk of abnormal neurodevelopment. The timing and patterns of brain reorganization underlying IUGR are poorly documented. We developed a rabbit model of IUGR allowing neonatal neurobehavioral assessment and high resolution brain diffusion magnetic resonance imaging (MRI). The aim of the study was to describe the pattern and functional correlates of fetal brain reorganization induced by IUGR. IUGR was induced in 10 New Zealand fetal rabbits by ligation of 40-50% of uteroplacental vessels in one horn at 25 days of gestation. Ten contralateral horn fetuses were used as controls. Cesarean section was performed at 30 days (term 31 days). At postnatal day +1, neonates were assessed by validated neurobehavioral tests including evaluation of tone, spontaneous locomotion, reflex motor activity, motor responses to olfactory stimuli, and coordination of suck and swallow. Subsequently, brains were collected and fixed and MRI was performed using a high resolution acquisition scheme. Global and regional (manual delineation and voxel based analysis) diffusion tensor imaging parameters were analyzed. IUGR was associated with significantly poorer neurobehavioral performance in most domains. Voxel based analysis revealed fractional anisotropy (FA) differences in multiple brain regions of gray and white matter, including frontal, insular, occipital and temporal cortex, hippocampus, putamen, thalamus, claustrum, medial septal nucleus, anterior commissure, internal capsule, fimbria of hippocampus, medial lemniscus and olfactory tract. Regional FA changes were correlated with poorer outcome in neurobehavioral tests. IUGR is associated with a complex pattern of brain reorganization already at birth, which may open opportunities for early intervention. Diffusion MRI can offer suitable imaging biomarkers to characterize and monitor brain reorganization due to fetal diseases.

  10. Neonatal Neurobehavior and Diffusion MRI Changes in Brain Reorganization Due to Intrauterine Growth Restriction in a Rabbit Model

    PubMed Central

    Eixarch, Elisenda; Batalle, Dafnis; Illa, Miriam; Muñoz-Moreno, Emma; Arbat-Plana, Ariadna; Amat-Roldan, Ivan; Figueras, Francesc; Gratacos, Eduard

    2012-01-01

    brain reorganization due to fetal diseases. PMID:22347486

  11. Brain involvement in Charcot-Marie-Tooth disease due to ganglioside-induced differentiation associated-protein 1 mutation.

    PubMed

    Al-Ghamdi, Fouad; Anselm, Irina; Yang, Edward; Ghosh, Partha S

    2017-09-01

    Charcot-Marie-Tooth (CMT) due to ganglioside-induced differentiation associated-protein 1 (GDAP1) gene mutation can be inherited as an autosomal recessive (severe phenotype) or dominant (milder phenotype) disorder. GDAP1 protein, located in the outer mitochondrial membrane, is involved in the mitochondrial fission. Brain imaging abnormalities have not been reported in this condition. We described an 8-year-old boy who had an early onset autosomal recessive neuropathy. Whole exome sequencing revealed compound heterozygous mutations in the GDAP1 gene: c.313_313delA, p.Arg105Glufs*3 - a novel mutation (maternally inherited) and c.358C>T, pR120W - a known pathogenic mutation (paternally inherited). He had abnormal brain MRI findings since infancy localized to the middle cerebellar peduncles and cerebellar white matter with sparing of the supratentorial brain. We speculate that GDAP1 protein due to its widespread distribution and mitochondrial location is responsible for these imaging abnormalities. This report expands the spectrum of brain imaging abnormalities seen in different types of CMT. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Variable resolution electromagnetic tomography (VARETA) in evaluation of compression of cerebral arteries due to deep midline brain lesions.

    PubMed

    Fernández-Bouzas, Antonio; Harmony, Thalía; Fernández, Thalía; Ricardo-Garcell, Josefina; Santiago, Efraín

    2004-01-01

    Hemispheric tumors produced electroencephalographic (EEG) delta activity mainly due to deafferentation of cerebral cortex. In small, deep midline lesions that compressed cerebral arteries, the most important abnormality should have been in EEG theta band that selectively responded to brain ischemia. Frequency domain-variable resolution electromagnetic tomography (FD-VARETA) has been applied satisfactorily to the study of brain tumors, cerebral infarcts, and brain hemorrhages and was shown to localize areas of hypoperfusion. Twelve patients with deep midline lesions compressing different cerebral arteries were studied. Computer tomography (CT) and/or magnetic resonance imaging (MRI) as well as quantitative EEG with source calculation in frequency domain were obtained. Brain electromagnetic tomographies (BETs) were calculated to evaluate localization and extension of functional abnormalities. Ten of twelve cases presented abnormal sources in theta band as main abnormal source. In only two cases was the main source in delta band, but these cases also had abnormal Z values in theta band. In four patients there were only abnormal values in theta range. Sources of abnormal theta activity were observed in regions irrigated by the arteries compressed. In deep midline lesions, compression of cerebral arteries producing relative ischemia may explain abnormal EEG sources in theta band. Patients with main source in theta band showed vascular compression and some patients exhibited vasogenic edema. Thus, theta might be due to relative ischemia produced by both hypoperfusion and edema. Once again, VARETA has found to be very useful in evaluation of functional abnormalities.

  13. Changes in Mice Brain Spontaneous Electrical Activity during Cortical Spreading Depression due to Mobile Phone Radiation

    PubMed Central

    Sallam, Samera M.; Mohamed, Ehab I.; Dawood, Abdel-Fattah B.

    2008-01-01

    The objective of the present study was to investigate changes in spontaneous EEG activity during cortical spreading depression (CSD) in mice brain. The cortical region of anaesthetized mice were exposed to the electromagnetic fields (EMFs) emitted from a mobile phone (MP, 935.2-960.2 MHz, 41.8 mW/cm2). The effect of EMFs on EEG was investigated before and after exposure to different stimuli (MP, 2% KCl, and MP & 2% KCl). The records of brain spontaneous EEG activity, slow potential changes (SPC), and spindle shaped firings were obtained through an interfaced computer. The results showed increases in the amplitude of evoked spindles by about 87%, 17%, and 226% for MP, 2% KCl, and MP & 2% KCl; respectively, as compared to values for the control group. These results showed that the evoked spindle is a more sensitive indicator of the effect of exposure to EMFs from MP. PMID:23675079

  14. Multiple Brain Abscesses Due to Aspergillus Fumigatus in a Patient With Liver Cirrhosis: A Case Report.

    PubMed

    Tang, Hung-Jen; Liu, Wei-Lun; Chang, Tsung Chain; Li, Ming-Chi; Ko, Wen-Chien; Wu, Chi-Jung; Chuang, Yin-Ching; Lai, Chih-Cheng

    2016-03-01

    Invasive cerebral aspergillosis always developed in immunocompromised host. Early diagnosis may save life in this critical condition; however, it is difficult to reach. Herein, we presented an unusual case of invasive cerebral aspergillosis in a cirrhotic patient. A 47-year-old man presented with progressive deterioration of consciousness for three days. The patient had a history of alcoholic liver cirrhosis, Child-Pugh class C. Magnetic resonance imaging (MRI) of brain showed multi-focal parenchymal lesions, which was consistent with multiple brain abscesses. The diagnosis of invasive cerebral aspergillosis was made by molecular based laboratory methods including Aspergillus galactomannan antigen assay and oligonucleotide array. Despite treatment with the antifungal agent, Amphotericin B, the patient died at the ninth day of hospitalization. Our findings suggest that liver cirrhosis can be one of risk factors of invasive cerebral aspergillosis, and support the diagnosing usefulness of MRI, Aspergillus galactomannan antigen assay, and oligonucleotide array.

  15. Speech and language therapy for dysarthria due to non-progressive brain damage.

    PubMed

    Sellars, C; Hughes, T; Langhorne, P

    2002-01-01

    Dysarthria is a common sequel of non-progressive brain damage (typically stroke and traumatic brain damage). Impairment-based therapy and a wide variety of compensatory management strategies are undertaken by speech and language therapists with this patient population. To determine the efficacy of speech and language therapy interventions for adults with dysarthria following non-progressive brain damage. This review has drawn on the search strategies developed for the following Cochrane Groups as a whole: Stroke, Injuries, Movement Disorders and Infectious Diseases. Relevant trials were identified in the Specialised Registers of Controlled Trials (see Review Group details for more information). We also searched the trials register of the Cochrane Rehabilitation and Related Therapies Field. The Trials Registers were last searched in December 2001. The Cochrane Controlled Trials Register (Cochrane Library 2002, Issue 1), MEDLINE (1966-December 2001), EMBASE (1980-December 2001), CINAHL (1983-December 2001), PsycINFO (1974-February 2002) and Linguistics and Language Behavior Abstracts (1983-October 2001) were searched electronically. We handsearched the International Journal of Language and Communication Disorders (1966-2002, Issue 1) and selected conference proceedings, and scanned the reference lists of relevant articles. Colleagues were approached to identify other possible published and unpublished studies. Unconfounded randomised controlled trials. One reviewer assessed trial quality. Two co-reviewers were available to examine any potential trials for possible inclusion in the review. No trials of the required standard were identified. There is no evidence of the quality required by this review to support or refute the effectiveness of Speech and Language Therapy interventions for dysarthria following non-progressive brain damage. There is an urgent need for good quality research in this area.

  16. Speech and language therapy for dysarthria due to non-progressive brain damage.

    PubMed

    Sellars, C; Hughes, T; Langhorne, P

    2005-07-20

    Dysarthria is a common sequel of non-progressive brain damage (typically stroke and traumatic brain damage). Impairment-based therapy and a wide variety of compensatory management strategies are undertaken by speech and language therapists with this patient population. To determine the efficacy of speech and language therapy interventions for adults with dysarthria following non-progressive brain damage. We searched the trials registers of the following Cochrane Groups: Stroke, Injuries, Movement Disorders and Infectious Diseases. We also searched the trials register of the Cochrane Rehabilitation and Related Therapies Field. The trials registers were last searched in September 2004. The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2004), MEDLINE (1966 to September 2004), EMBASE (1980 to September 2004), CINAHL (1983 to September 2004), PsycINFO (1974 to October 2004), and Linguistics and Language Behavior Abstracts (1983 to December 2004) were searched electronically. We handsearched the International Journal of Language and Communication Disorders (1966 to 2005, Issue 1) and selected conference proceedings, and scanned the reference lists of relevant articles. We approached colleagues and speech and language therapy training institutions to identify other possible published and unpublished studies. Unconfounded randomised controlled trials (RCTs). One author assessed trial quality. Two co-authors were available to examine any potential trials for possible inclusion in the review. No trials of the required standard were identified. There is no evidence of the quality required by this review to support or refute the effectiveness of speech and language therapy interventions for dysarthria following non-progressive brain damage. Despite the recent commencement of a RCT of optimised speech and language therapy for communication difficulties after stroke, there continues to be an urgent need for good quality research in this

  17. Nonlinear changes in brain electrical activity due to cell phone radiation.

    PubMed

    Marino, Andrew A; Nilsen, Erik; Frilot, Clifton

    2003-07-01

    We studied the effect of an electromagnetic field from a cellular telephone on brain electrical activity, using a novel analytical method based on a nonlinear model. The electroencephalogram (EEG) from rabbits was embedded in phase space and local recurrence plots were calculated and quantified using recurrence quantitation analysis to permit statistical comparisons between filtered segments of exposed and control epochs from individual rabbits. When the rabbits were exposed to the radiation from a standard cellular telephone (800 MHz band, 600 mW maximum radiated power) under conditions that simulated normal human use, the EEG was significantly affected in nine of ten animals studied. The effect occurred beginning about 100 ms after initiation of application of the field and lasted approximately 300 ms. In each case, the fields increased the randomness in the EEG. A control procedure ruled out the possibility that the observations were a product of the method of analysis. No differences were found between exposed and control epochs in any animal when the experiment was repeated after the rabbits had been sacrificed, indicating that absorption of radiation by the EEG electrodes could not account for the observed effect. No effect was seen when deposition of energy in the brain was minimized by repositioning the radiating antenna from the head to the chest, showing that the type of tissue that absorbed the energy determined the observed changes in the EEG. We conclude that, in normal use, the fields from a standard cellular telephone can alter brain function as a consequence of absorption of energy by the brain. Copyright 2003 Wiley-Liss, Inc.

  18. Anatomical compression due to high volume convection-enhanced delivery to the brain

    PubMed Central

    Valles, Francisco; Fiandaca, Massimo S.; Bringas, John; Dickinson, Peter; LeCouteur, Richard; Higgins, Robert; Berger, Mitchel; Forsayeth, John; Bankiewicz, Krystof S.

    2009-01-01

    Objective Our group has pioneered the use of gadolinium liposomes (GDL) in convection-enhanced delivery (CED) using real-time MRI (magnetic resonance imaging) to visualize the distribution of therapeutics in in non-human primate (NHP) and canine brain. We have shown that this procedure is highly predictable and safe. In the course of recent studies, however, we noted that infusion of large volumes caused local anatomical alterations, such as ventricular compression, to occur. This study reports our analysis of CED infusions into normal brains and those compromised by tumors and how monitoring the CED infusion with MRI may be helpful in preventing some complications. Methods A total of fifty-four CED infusions using gadolinium liposomes (GDL) were performed in seven canines and ten NHPs, and monitored using real-time MRI. The canines, harboring brain tumors, received infusions of GDL as well as a chemotherapeutic agent via CED. The NHPs were normal and received GDL infusions alone. Real-time analysis of the CED infusion was carried looking for proper catheter position, and infusion reflux, leakage, and mass effect. Retrospective analysis allowed assessment of CED volume of distribution versus volume of infusion. Results Approximately ten percent of these infusions caused anatomical compression of the ventricles, especially in the canines with tumors. Reflux along the cannula and leakage of infusate into the ventricular CSF or subarachnoid space was seen. Animal behavior, however, did not appear to be affected acutely or during the time course of the study, and no ventricular compression was noted two weeks after the CED infusion on further brain imaging studies. Conclusion These findings illustrate the value of being able to monitor infusions with real time MRI in order to identify phenomena such as reflux along the cannula, leakage of infusate, and ventricular compression. Especially in tumor patients, the latter could be associated with morbidity. PMID:19687704

  19. Role of MicroRNAs in innate neuroprotection mechanisms due to preconditioning of the brain

    PubMed Central

    Jimenez-Mateos, Eva M.

    2015-01-01

    Insults to the brain that are sub-threshold for damage activate endogenous protective pathways, which can temporarily protect the brain against a subsequent harmful episode. This mechanism has been named as tolerance and its protective effects have been shown in experimental models of ischemia and epilepsy. The preconditioning-stimulus can be a short period of ischemia or mild seizures induced by low doses of convulsant drugs. Gene-array profiling has shown that both ischemic and epileptic tolerance feature large-scale gene down-regulation but the mechanism are unknown. MicroRNAs are a class of small non-coding RNAs of ~20–22 nucleotides length which regulate gene expression at a post-transcriptional level via mRNA degradation or inhibition of protein translation. MicroRNAs have been shown to be regulated after non-harmful and harmful stimuli in the brain and to contribute to neuroprotective mechanisms. This review focuses on the role of microRNAs in the development of tolerance following ischemic or epileptic preconditioning. PMID:25954143

  20. Validation of a stereo camera system to quantify brain deformation due to breathing and pulsatility.

    PubMed

    Faria, Carlos; Sadowsky, Ofri; Bicho, Estela; Ferrigno, Giancarlo; Joskowicz, Leo; Shoham, Moshe; Vivanti, Refael; De Momi, Elena

    2014-11-01

    A new stereo vision system is presented to quantify brain shift and pulsatility in open-skull neurosurgeries. The system is endowed with hardware and software synchronous image acquisition with timestamp embedding in the captured images, a brain surface oriented feature detection, and a tracking subroutine robust to occlusions and outliers. A validation experiment for the stereo vision system was conducted against a gold-standard optical tracking system, Optotrak CERTUS. A static and dynamic analysis of the stereo camera tracking error was performed tracking a customized object in different positions, orientations, linear, and angular speeds. The system is able to detect an immobile object position and orientation with a maximum error of 0.5 mm and 1.6° in all depth of field, and tracking a moving object until 3 mm/s with a median error of 0.5 mm. Three stereo video acquisitions were recorded from a patient, immediately after the craniotomy. The cortical pulsatile motion was captured and is represented in the time and frequency domain. The amplitude of motion of the cloud of features' center of mass was inferior to 0.8 mm. Three distinct peaks are identified in the fast Fourier transform analysis related to the sympathovagal balance, breathing, and blood pressure with 0.03-0.05, 0.2, and 1 Hz, respectively. The stereo vision system presented is a precise and robust system to measure brain shift and pulsatility with an accuracy superior to other reported systems.

  1. Green tea polyphenols attenuate glial swelling and mitochondrial dysfunction following oxygen-glucose deprivation in cultures

    USDA-ARS?s Scientific Manuscript database

    Astrocyte swelling is a major component of cytotoxic brain edema in ischemia. Oxidative stress and mitochondrial dysfunction have been hypothesized to contribute to such swelling in cultures. We investigated the protective effects of polyphenol-rich green tea extract (GTE) on key features of ischemi...

  2. Osmotic swelling characteristics of glial cells in the murine hippocampus, cerebellum, and retina in situ.

    PubMed

    Hirrlinger, Petra G; Wurm, Antje; Hirrlinger, Johannes; Bringmann, Andreas; Reichenbach, Andreas

    2008-05-01

    Glial cells are proposed to play a major role in the ionic and osmotic homeostasis in the CNS. Swelling of glial cells contributes to the development of edema in neural tissue under pathological conditions such as trauma and ischemia. In this study, we compared the osmotic swelling characteristics of murine hippocampal astrocytes, cerebellar Bergmann glial cells, and retinal Müller glial cells in acutely isolated tissue slices in response to hypoosmotic stress and pharmacological blockade of Kir channels. Hypoosmotic challenge induced an immediate swelling of somata in the majority of Bergmann glial cells and hippocampal astrocytes investigated, whereas Müller cell bodies displayed a substantial delay in the onset of swelling and hippocampal astroglial processes remained unaffected. Blockade of Kir channels under isoosmotic conditions had no swelling-inducing effect in Müller cell somata but caused a swelling in brain astrocytic somata and processes. Blockade of Kir channels under hypoosmotic conditions induced an immediate and strong swelling in Müller cell somata, but had no cumulative effect to brain astroglial somata. No regulatory volume decrease could be observed in all cell types. The data suggest that Kir channels are differently implicated in cell volume homeostasis of retinal Müller cells and brain astrocytes and that Müller cells and brain astrocytes differ in their osmotic swelling properties.

  3. Mice with neuropathic pain exhibit morphine tolerance due to a decrease in the morphine concentration in the brain.

    PubMed

    Ochiai, Wataru; Kaneta, Mitsumasa; Nagae, Marina; Yuzuhara, Ami; Li, Xin; Suzuki, Haruka; Hanagata, Mika; Kitaoka, Satoshi; Suto, Wataru; Kusunoki, Yoshiki; Kon, Risako; Miyashita, Kazuhiko; Masukawa, Daiki; Ikarashi, Nobutomo; Narita, Minoru; Suzuki, Tsutomu; Sugiyama, Kiyoshi

    2016-09-20

    The chronic administration of morphine to patients with neuropathic pain results in the development of a gradual tolerance to morphine. Although the detailed mechanism of this effect has not yet been elucidated, one of the known causes is a decrease in μ-opioid receptor function with regard to the active metabolite of morphine, M-6-G(morphine-6-glucuronide), in the ventrotegmental area of the midbrain. In this study, the relationship between the concentration of morphine in the brain and its analgesic effect was examined after the administration of morphine in the presence of neuropathic pain. Morphine was orally administered to mice with neuropathic pain, and the relationship between morphine's analgesic effect and its concentration in the brain was analysed. In addition, the expression levels of the conjugation enzyme, UGT2B (uridine diphosphate glucuronosyltransferase), which has morphine as its substrate, and P-gp, which is a transporter involved in morphine excretion, were examined. In mice with neuropathic pain, the concentration of morphine in the brain was significantly decreased, and a correlation was found between this decrease and the decrease in the analgesic effect. It was considered possible that this decrease in the brain morphine concentration may be due to an increase in the expression level of P-gp in the small intestine and to an increase in the expression level and binding activity of UGT2B in the liver. The results of this study suggest the possibility that a sufficient analgesic effect may not be obtained when morphine is administered in the presence of neuropathic pain due to a decrease in the total amount of morphine and M-6-G that reach the brain. Copyright © 2016. Published by Elsevier B.V.

  4. Association between ventilatory settings and development of acute respiratory distress syndrome in mechanically ventilated patients due to brain injury.

    PubMed

    Tejerina, Eva; Pelosi, Paolo; Muriel, Alfonso; Peñuelas, Oscar; Sutherasan, Yuda; Frutos-Vivar, Fernando; Nin, Nicolás; Davies, Andrew R; Rios, Fernando; Violi, Damian A; Raymondos, Konstantinos; Hurtado, Javier; González, Marco; Du, Bin; Amin, Pravin; Maggiore, Salvatore M; Thille, Arnaud W; Soares, Marco Antonio; Jibaja, Manuel; Villagomez, Asisclo J; Kuiper, Michael A; Koh, Younsuck; Moreno, Rui P; Zeggwagh, Amine Ali; Matamis, Dimitrios; Anzueto, Antonio; Ferguson, Niall D; Esteban, Andrés

    2017-04-01

    In neurologically critically ill patients with mechanical ventilation (MV), the development of acute respiratory distress syndrome (ARDS) is a major contributor to morbidity and mortality, but the role of ventilatory management has been scarcely evaluated. We evaluate the association of tidal volume, level of PEEP and driving pressure with the development of ARDS in a population of patients with brain injury. We performed a secondary analysis of a prospective, observational study on mechanical ventilation. We included 986 patients mechanically ventilated due to an acute brain injury (hemorrhagic stroke, ischemic stroke or brain trauma). Incidence of ARDS in this cohort was 3%. Multivariate analysis suggested that driving pressure could be associated with the development of ARDS (odds ratio for unit increment of driving pressure 1.12; confidence interval for 95%: 1.01 to 1.23) whereas we did not observe association for tidal volume (in ml per kg of predicted body weight) or level of PEEP. ARDS was associated with an increase in mortality, longer duration of mechanical ventilation, and longer ICU length of stay. In a cohort of brain-injured patients the development of ARDS was not common. Driving pressure was associated with the development of this disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Human brain microvascular endothelial cells resist elongation due to shear stress.

    PubMed

    Reinitz, Adam; DeStefano, Jackson; Ye, Mao; Wong, Andrew D; Searson, Peter C

    2015-05-01

    Endothelial cells in straight sections of vessels are known to elongate and align in the direction of flow. This phenotype has been replicated in confluent monolayers of bovine aortic endothelial cells and human umbilical vein endothelial cells (HUVECs) in cell culture under physiological shear stress. Here we report on the morphological response of human brain microvascular endothelial cells (HBMECs) in confluent monolayers in response to shear stress. Using a microfluidic platform we image confluent monolayers of HBMECs and HUVECs under shear stresses up to 16 dyne cm(-2). From live-cell imaging we quantitatively analyze the cell morphology and cell speed as a function of time. We show that HBMECs do not undergo a classical transition from cobblestone to spindle-like morphology in response to shear stress. We further show that under shear stress, actin fibers are randomly oriented in the cells indicating that there is no cytoskeletal remodeling. These results suggest that HBMECs are programmed to resist elongation and alignment under shear stress, a phenotype that may be associated with the unique properties of the blood-brain barrier.

  6. [Mitochondrial encephalopathy due to complex I deficiency. Brain tissue biopsy findings and clinical course following pharmacological].

    PubMed

    Jiménez-Caballero, P E; Mollejo-Villanueva, M; Alvarez-Tejerina, A

    Mitochondrial encephalomyopathies belong to a heterogeneous group of diseases with a range of neurological symptoms caused by a dysfunction somewhere in the nervous system. They may arise from mutations of the mitochondrial DNA or nuclear DNA in the genes that code for the subunits of the respiratory chain. The results obtained from using different drugs to treat these diseases vary widely. A 33-year-old female with a history of migraine with aura, who was admitted to hospital because of epileptic seizures. Neuroimaging tests showed left-side occipital insult and a biopsy study of a sample of brain tissue revealed gliosis and vacuolisation of the white matter. Lactic acid levels in blood were normal. No ragged red fibres were seen in the muscle biopsy, but there was evidence of a complex I deficiency in the respiratory chain. After establishing treatment with coenzyme Q and riboflavin, the patient had no further episodes of neurological disorders. The absence of elevated levels of lactate, ragged red fibres in the muscle biopsy or the negative results for mutations in the genetic study do not rule out the possible existence of a mitochondrial disease. The gliosis and vacuolisation of the white matter with respect to the neurons that were found in the results of the brain tissue biopsy must lead us to consider a mitochondrial disease.

  7. Cerebral salt-wasting syndrome due to hemorrhagic brain infarction: a case report.

    PubMed

    Tanaka, Tomotaka; Uno, Hisakazu; Miyashita, Kotaro; Nagatsuka, Kazuyuki

    2014-07-23

    Cerebral salt-wasting syndrome is a condition featuring hyponatremia and dehydration caused by head injury, operation on the brain, subarachnoid hemorrhage, brain tumor and so on. However, there are a few reports of cerebral salt-wasting syndrome caused by cerebral infarction. We describe a patient with cerebral infarction who developed cerebral salt-wasting syndrome in the course of hemorrhagic transformation. A 79-year-old Japanese woman with hypertension and arrhythmia was admitted to our hospital for mild consciousness disturbance, conjugate deviation to right, left unilateral spatial neglect and left hemiparesis. Magnetic resonance imaging revealed a broad ischemic change in right middle cerebral arterial territory. She was diagnosed as cardiogenic cerebral embolism because atrial fibrillation was detected on electrocardiogram on admission. She showed hyponatremia accompanied by polyuria complicated at the same time with the development of hemorrhagic transformation on day 14 after admission. Based on her hypovolemic hyponatremia, she was evaluated as not having syndrome of inappropriate secretion of antidiuretic hormone but cerebral salt-wasting syndrome. She fortunately recovered with proper fluid replacement and electrolyte management. This is a rare case of cerebral infarction and cerebral salt-wasting syndrome in the course of hemorrhagic transformation. It may be difficult to distinguish cerebral salt-wasting syndrome from syndrome of inappropriate antidiuretic hormone, however, an accurate assessment is needed to reveal the diagnosis of cerebral salt-wasting syndrome because the recommended fluid management is opposite in the two conditions.

  8. Traumatic brain injury due to gunshot wounds: a single institution's experience with 442 consecutive patients.

    PubMed

    Solmaz, Ilker; Kural, Cahit; Temiz, Cağlar; Seçer, Halil Ibrahim; Düz, Bülent; Gönül, Engin; Izci, Yusuf

    2009-07-01

    Traumatic brain injury (TBI) caused by a gunshot wound is a complex injury with a broad spectrum of symptoms and high rates of mortality and morbidity. This study presents an evaluation of TBI caused by gunshot wounds presenting at a single institution and discusses possible predictive factors for the outcome of surgical intervention. The study sample consisted of 442 patients who underwent surgery for TBI over a 16-year period. All injuries were caused by gunshot wounds, such as bullets and shrapnel. All patients underwent surgical intervention. Almost all patients (99.3%) were male, and the mean patient age was 22.3 years. Wounds were caused by shrapnel in 68 percent of patients. The Glasgow Coma Scale (GCS) score at admission was below 8 in 116 patients (26.2%) and above 8 in 326 patients (73.8%). In total, 47 patients (10.6%) died despite surgical management, with diffuse brain injury the most common cause of death. Low GCS scores, ventricular injuries and bihemispheric injuries are correlated with poor prognosis. Early and less invasive surgery in conjunction with short transportation time to the hospital could decrease mortality rates.

  9. Manic Symptoms Due to Methylphenidate Use in an Adolescent with Traumatic Brain Injury

    PubMed Central

    Ekinci, Ozalp; Direk, Meltem Çobanoğullari; Ekinci, Nuran; Okuyaz, Cetin

    2016-01-01

    Almost one-fifth of children who sustain a traumatic brain injury (TBI) are under the risk of attention problems after injury. The efficacy and tolerability of methylphenidate (MPH) in children with a history of TBI have not been completely identified. In this case report, MPH-induced manic symptoms in an adolescent with TBI will be summarized. A male patient aged 17 years was admitted with the complaints of attention difficulties on schoolwork and forgetfullness which became evident after TBI. Long-acting MPH was administered with the dose of 18 mg/day for attention problems. After one week, patient presented with the complaints of talking to himself, delusional thoughts, irritability and sleeplessness. This case highlights the fact that therapeutic dose of MPH may cause mania-like symptoms in children with TBI. Close monitarization and slow dose titration are crucial when considering MPH in children with TBI. PMID:27489389

  10. Prevention and Treatment of Traumatic Brain Injury Due to Rapid-Onset Natural Disasters

    PubMed Central

    Regens, James L.; Mould, Nick

    2014-01-01

    The prevention and treatment of traumatic brain injury (TBI) attributable to rapid-onset natural disasters is a major challenge confronting disaster preparedness planners and emergency medical personnel responding to those incidents. The kinetic energy released by rapid-onset natural disasters such as earthquakes, hurricanes or typhoons, and tornadoes can cause mild, moderate, or severe TBIs. As a result, neurotrauma is a major risk factor for mortality and morbidity outcomes within the spatial domain impacted by a rapid-onset natural disaster. This review article elucidates major challenges associated with immediate emergency medical response, long-term care, and prevention of post-event increases in pediatric TBIs because of child abuse when rapid-onset natural disasters occur. PMID:24783188

  11. Prevention and treatment of traumatic brain injury due to rapid-onset natural disasters.

    PubMed

    Regens, James L; Mould, Nick

    2014-01-01

    The prevention and treatment of traumatic brain injury (TBI) attributable to rapid-onset natural disasters is a major challenge confronting disaster preparedness planners and emergency medical personnel responding to those incidents. The kinetic energy released by rapid-onset natural disasters such as earthquakes, hurricanes or typhoons, and tornadoes can cause mild, moderate, or severe TBIs. As a result, neurotrauma is a major risk factor for mortality and morbidity outcomes within the spatial domain impacted by a rapid-onset natural disaster. This review article elucidates major challenges associated with immediate emergency medical response, long-term care, and prevention of post-event increases in pediatric TBIs because of child abuse when rapid-onset natural disasters occur.

  12. Cognitive performance in transient global hypoxic brain injury due to moderate drowning.

    PubMed

    Nucci, Mariana Penteado; Lukasova, Katerina; Vieira, Gilson; Sato, João Ricardo; Amaro Júnior, Edson

    2017-09-19

    Drowning is a serious and frequently neglected public health threat. Primary respiratory impairment after submersion often leads to brain dysfunction. Depending on the period of global hypoxia (respiratory failure), clinical aspects of neurological dysfunction are evident on the first evaluation after the water rescue. Nowadays, many neuropsychological assessments after drowning are inconclusive, with some studies reporting only minor neurological or cognitive impairments. The aim of this study is to identify measures in neuropsychological tests that most contribute to classify volunteers as moderate drowning subjects or healthy controls. To the best of our knowledge, this study is the first neuropsychological prospective case-control study of moderate drowning in a country with large coastal cities. Fifteen moderate drowning patients (DP), who met the inclusion criteria, were compared with 18 healthy controls (HC). All subjects were assessed on memory, learning, visual spatial ability, executive function, attention, and general intellectual functioning and underwent structural magnetic resonance (MR) imaging of the brain at 3.0 T, in order to exclude subjects with anatomic abnormalities. Neuropsychological tests assessing learning, execution function, and verbal fluency-Rey Auditory Verbal Learning Test (RAVLT) general learning ability, Digit Span total, Phonological Verbal Fluency (total FAS correct), and Brief Visuospatial Memory Test Revised (BVMT) correct recognition-have the strongest discriminating ability, using predictive models via the partial least squares (PLS) approach for data classification, while the other tests have shown similar predictive values between groups. Learning, execution function, and verbal fluency domains were the most critically affected domains. Serious impairments in the same domains have already been reported in severe drowning cases, and we hypothesize that subtle alterations found in moderate drowning cases, although not

  13. On the Pressure Response in the Brain due to Short Duration Blunt Impacts

    PubMed Central

    Pearce, Christopher W.; Young, Philippe G.

    2014-01-01

    When the head is subject to non-penetrating (blunt) impact, contusion-type injuries are commonly identified beneath the impact site (the coup) and, in some instances, at the opposite pole (the contre-coup). This pattern of injury has long eluded satisfactory explanation and blunt head injury mechanisms in general remain poorly understood. There are only a small number of studies in the open literature investigating the head's response to short duration impacts, which can occur in collisions with light projectiles. As such, the head impact literature to date has focussed almost exclusively on impact scenarios which lead to a quasi-static pressure response in the brain. In order to investigate the response of the head to a wide range of impact durations, parametric numerical studies were performed on a highly bio-fidelic finite element model of the human head created from in vivo magnetic resonance imaging (MRI) scan data with non-linear tissue material properties. We demonstrate that short duration head impacts can lead to potentially deleterious transients of positive and negative intra-cranial pressure over an order of magnitude larger than those observed in the quasi-static regime despite reduced impact force and energy. The onset of this phenomenon is shown to be effectively predicted by the ratio of impact duration to the period of oscillation of the first ovalling mode of the system. These findings point to dramatically different pressure distributions in the brain and hence different patterns of injury depending on projectile mass, and provide a potential explanation for dual coup/contre-coup injuries observed clinically. PMID:25478695

  14. Cinnamon Polyphenols Attenuate Neuronal Death and Glial Swelling in Ischemic Injury

    USDA-ARS?s Scientific Manuscript database

    Brain edema is a major complication associated with ischemic stroke and is characterized by a volumetric enlargement of the brain. Astrocyte swelling is a major component of brain edema. We investigated the protective effects of polyphenols isolated from green tea and cinnamon in C6 glial cultures s...

  15. Targeting Epigenetic Mechanisms in Pain Due to Trauma and Traumatic Brain Injury (TBI)

    DTIC Science & Technology

    2015-10-01

    particularly likely to involve TBI, peripheral trauma or both. Disability due to pain and other causes is very high amongst such patients. We have no...Chemokine, Disability , Analgesia, Spinal Cord 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 16 19a. NAME OF...particularly likely to involve TBI, peripheral trauma or both.  Disability  due  to pain and other causes is very high amongst such patients. We have no

  16. Indolent palatal swelling: Catch 22

    PubMed Central

    Sharma, Preeti; Wadhwan, Vijay; Kumar, K. V. Arun; Venkatesh, Arvind; Thapa, Timsy

    2016-01-01

    We present an interesting but intriguing case of an indolent palatal swelling. The lesion was asymptomatic causing little discomfort to the patient and thus was an incidental clinical finding. Provisional diagnosis was a benign, minor salivary gland tumor. Clinical differential diagnoses included benign lymphoepithelial lesion or mucus extravasation phenomenon. Nevertheless, we also considered malignancies such as mucoepidermoid carcinoma, lymphoma, and neoplasm of the maxillary sinus. However, the histopathology revealed a rare clinicopathologic entity prompting immediate treatment of the lesion. PMID:28356700

  17. Swelling-resistant nuclear fuel

    SciTech Connect

    Arsenlis, Athanasios; Satcher, Jr., Joe; Kucheyev, Sergei O

    2011-12-27

    A nuclear fuel according to one embodiment includes an assembly of nuclear fuel particles; and continuous open channels defined between at least some of the nuclear fuel particles, wherein the channels are characterized as allowing fission gasses produced in an interior of the assembly to escape from the interior of the assembly to an exterior thereof without causing significant swelling of the assembly. Additional embodiments, including methods, are also presented.

  18. Concurrent changes in aggregation and swelling of coal particles in solvents

    SciTech Connect

    Nishioka, M.

    1995-12-31

    A new method of coal swelling has been developed tinder the condition of low coal concentrations with continuous mixing of coal and solvent. The change in particle size distributions by a laser scattering procedure was used for the evaluation of coal swelling. Particle size distributions in good and poor solvents were nearly equal, but reversibly changed in good solvents from time to time. The effects of solubles and coal concentrations on the distributions were small. It was concluded that aggregate d coal particles disaggregate in good solvents, and that an increase in the particle size distribution due to swelling in good solvents are compensated by a decrease in the particle size due to disaggregation. Therefore, the behavior of coal particles in solvents is controlled by aggregation in addition to coal swelling. This implies that an increase in the particle size due to coal swelling in actual processes is not so large as expected by the results obtained from the conventional coal swelling methods.

  19. Precipitants of hepatic encephalopathy induce rapid astrocyte swelling in an oxidative stress dependent manner.

    PubMed

    Lachmann, Vera; Görg, Boris; Bidmon, Hans Jürgen; Keitel, Verena; Häussinger, Dieter

    2013-08-15

    Hepatic encephalopathy (HE) is seen as the clinical manifestation of a low grade cerebral edema with formation of reactive oxygen and nitrogen species (RNOS). Astrocyte swelling is a crucial event and in cultured astrocytes HE-relevant factors almost instantaneously induce the formation of RNOS. However, short term effects of ammonia, inflammatory cytokines and RNOS on the volume of astrocytes and other brain cells as well as the underlying mechanisms are largely unknown, although a pathogenic link between RNOS formation and swelling in HE has been proposed. This issue was addressed in the present study by means of live-cell volume microscopy of brain cells in vitro. Ammonia, diazepam and pro-inflammatory cytokines such as tumor-necrosis factor-α (TNF-α), interferon-γ, interleukin-1β induced within 20min astrocyte swelling by about 25% accompanied by nuclear swelling of similar magnitude. Astrocyte swelling in response to NH4Cl, TNF-α or diazepam was abolished by the antioxidant epigallocatechin-gallate pointing to an involvement of RNOS. NH4Cl-induced astrocyte swelling was sensitive to inhibition of glutamine synthetase, NADPH oxidase or nitric oxide synthases. In line with a NMDA receptor-, prostanoid- and Ca(2+)-dependence of NH4Cl-induced RNOS formation, Ca(2+) chelation and inhibition of NMDA receptors or cyclooxygenase suppressed NH4Cl-induced astrocyte swelling, whereas the Ca(2+)-ionophore ionomycin, NMDA, glutamate and prostanoids induced rapid astrocyte swelling. NH4Cl also induced swelling of cultured microglia in a glutamine-synthesis dependent way, but had no effect on cell volume of cultured neurons. It is concluded that the pathways which trigger RNOS formation in astrocytes also trigger astrocyte swelling, whereas conversely and as shown previously hypoosmotic astrocyte swelling can induce RNOS formation. This establishes a complex interplay with an auto-amplificatory loop between RNOS formation and astrocyte swelling as an important event in

  20. Are the changes in the peripheral brain-derived neurotrophic factor levels due to platelet activation?

    PubMed Central

    Serra-Millàs, Montserrat

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) plays an important role in central nervous system development, neurogenesis and neuronal plasticity. BDNF is also expressed in several non-neuronal tissues, and it could play an important role in other processes, such as cancer, angiogenesis, etc. Platelets are the major source of peripheral BDNF. However, platelets also contain high amounts of serotonin; they express specific surface receptors during activation, and a multitude of pro-inflammatory and immunomodulatory bioactive compounds are secreted from the granules. Until recently, there was insufficient knowledge regarding the relationship between BDNF and platelets. Recent studies showed that BDNF is present in two distinct pools in platelets, in α-granules and in the cytoplasm, and only the BDNF in the granules is secreted following stimulation, representing 30% of the total BDNF in platelets. BDNF has an important role in the pathophysiology of depression. Low levels of serum BDNF have been described in patients with major depressive disorder, and BDNF levels increased with chronic antidepressant treatment. Interestingly, there is an association between depression and platelet function. This review analyzed studies that evaluated the relationship between BDNF and platelet activation and the effect of treatments on both parameters. Only a few studies consider this possible confounding factor, and it could be very important in diseases such as depression, which show changes in both parameters. PMID:27014600

  1. Calculation of change in brain temperatures due to exposure to a mobile phone.

    PubMed

    Van Leeuwen, G M; Lagendijk, J J; Van Leersum, B J; Zwamborn, A P; Hornsleth, S N; Kotte, A N

    1999-10-01

    In this study we evaluated for a realistic head model the 3D temperature rise induced by a mobile phone. This was done numerically with the consecutive use of an FDTD model to predict the absorbed electromagnetic power distribution, and a thermal model describing bioheat transfer both by conduction and by blood flow. We calculated a maximum rise in brain temperature of 0.11 degrees C for an antenna with an average emitted power of 0.25 W, the maximum value in common mobile phones, and indefinite exposure. Maximum temperature rise is at the skin. The power distributions were characterized by a maximum averaged SAR over an arbitrarily shaped 10 g volume of approximately 1.6 W kg(-1). Although these power distributions are not in compliance with all proposed safety standards, temperature rises are far too small to have lasting effects. We verified our simulations by measuring the skin temperature rise experimentally. Our simulation method can be instrumental in further development of safety standards.

  2. Managing Chemotherapy Side Effects: Swelling (Fluid Retention)

    MedlinePlus

    ... ational C ancer I nstitute Managing Chemotherapy Side Effects Swelling (Fluid retention) “My hands and feet were ... too much at one time. Managing Chemotherapy Side Effects: Swelling (Fluid retention) Weigh yourself. l Weigh yourself ...

  3. Hand Swelling during Exercise: A Concern?

    MedlinePlus

    ... and Conditions Edema What causes hand swelling during exercise? I walk several times a week, and my ... Edward R. Laskowski, M.D. Hand swelling during exercise is a fairly common problem. The cause isn' ...

  4. Pulmonary thrombosis associated with antidiuretic hormone replacement therapy due to secondary diabetes insipidus after traumatic brain injury: A case report

    PubMed Central

    Naito, Kiyohito; Watari, Taiji; Yasunari, Eisuke; Yamano, Miki; Mogami, Atsuhiko; Obayashi, Osamu; Kaneko, Kazuo

    2012-01-01

    INTRODUCTION Diabetes insipidus is a well-recognized complication of traumatic brain injury. The majority of patients with post-traumatic diabetes insipidus will require antidiuretic hormone (ADH) replacement therapy and tend to show dehydration. On the other hand, some negative effects of ADH on blood coagulation, such as increased platelet cohesion and the promotion of von Willebrand factor release, have also been reported. However, the incidence of thrombosis during antidiuretic hormone replacement therapy is disputed. PRESENTATION OF CASE A case of pulmonary thrombosis associated with ADH replacement therapy due to secondary diabetes insipidus after traumatic brain injury is presented here. DISCUSSION In our case, there were three factors that may have contributed to the observed thrombosis (dehydration, bed rest for a long period and ADH replacement therapy). CONCLUSION We believe that controlling urinary output and monitoring urinary and serum osmotic pressure are necessary for the management for diabetes insipidus patients after traumatic brain injury. In particular, we must carefully monitor the management of such patients during antidiuretic hormone replacement therapy. PMID:23131855

  5. Pulmonary thrombosis associated with antidiuretic hormone replacement therapy due to secondary diabetes insipidus after traumatic brain injury: A case report.

    PubMed

    Naito, Kiyohito; Watari, Taiji; Yasunari, Eisuke; Yamano, Miki; Mogami, Atsuhiko; Obayashi, Osamu; Kaneko, Kazuo

    2013-01-01

    Diabetes insipidus is a well-recognized complication of traumatic brain injury. The majority of patients with post-traumatic diabetes insipidus will require antidiuretic hormone (ADH) replacement therapy and tend to show dehydration. On the other hand, some negative effects of ADH on blood coagulation, such as increased platelet cohesion and the promotion of von Willebrand factor release, have also been reported. However, the incidence of thrombosis during antidiuretic hormone replacement therapy is disputed. A case of pulmonary thrombosis associated with ADH replacement therapy due to secondary diabetes insipidus after traumatic brain injury is presented here. In our case, there were three factors that may have contributed to the observed thrombosis (dehydration, bed rest for a long period and ADH replacement therapy). We believe that controlling urinary output and monitoring urinary and serum osmotic pressure are necessary for the management for diabetes insipidus patients after traumatic brain injury. In particular, we must carefully monitor the management of such patients during antidiuretic hormone replacement therapy. Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  6. Pyramidal tract activation due to subthalamic deep brain stimulation in Parkinson's disease.

    PubMed

    Mahlknecht, Philipp; Akram, Harith; Georgiev, Dejan; Tripoliti, Elina; Candelario, Joseph; Zacharia, Andre; Zrinzo, Ludvic; Hyam, Jonathan; Hariz, Marwan; Foltynie, Thomas; Rothwell, John C; Limousin, Patricia

    2017-08-01

    Subthalamic deep brain stimulation (STN-DBS) is an effective treatment for Parkinson's disease (PD), but can have side effects caused by stimulus spread to structures outside the target volume such as the pyramidal tract. To assess the relevance of pyramidal tract activation with STN-DBS in PD. In a multimodal, blinded study in 20 STN-DBS patients, we measured stimulation thresholds for evoking electromyographic activity in orbicularis oris and first dorsal interosseous muscles at each of 150 electrode sites. We also modeled the electric field spread and calculated its overlap with the estimated anatomical location of corticospinal and corticobulbar tracts from primary motor cortex using 3 Tesla MRI probabilistic tractography. Mean resting motor thresholds were significantly lower for the contralateral orbicularis oris (3.5 ± 1.0 mA) compared with ipsilaterally (4.1 ± 1.1 mA) and with the contralateral first dorsal interosseous (4.0 ± 1.2 mA). The modeled volumes of corticobulbar and corticospinal tract activated correlated inversely with the resting motor threshold of the contralateral orbicularis oris and first dorsal interosseous, respectively. Active motor thresholds were significantly lower compared with resting motor thresholds by around 30% to 35% and correlated with the clinically used stimulation amplitude. Backward multiple regression in 12 individuals with a "lateral-type" speech showed that stimulation amplitude, levodopa equivalent dose reduction postsurgery, preoperative speech intelligibility, and first dorsal interosseous resting motor thresholds explained 79.9% of the variance in postoperative speech intelligibility. Direct pyramidal tract activation can occur at stimulation thresholds that are within the range used in clinical routine. This spread of current compromises increase in stimulation strengths and is related to the development of side effects such as speech disturbances with chronic stimulation. © 2017 International

  7. Uncovering Latent Deficits Due to Mild Traumatic Brain Injury by Using Normobaric Hypoxia Stress

    PubMed Central

    Temme, Leonard; Bleiberg, Joseph; Reeves, Dennis; Still, David L.; Levinson, Dan; Browning, Rebecca

    2013-01-01

    Memory deficits and other cognitive symptoms frequently associated with mTBI are commonly thought to resolve within 7–10 days. This generalization is based principally on observations made in individuals who are in the unstressed environmental conditions typical of a clinic and so does not consider the impact of physiologic, environmental, or psychological stress. Normobaric hypoxic stress can be generated with normal mean sea level (MSL) air, which is about 21% oxygen (O2) and 78% nitrogen (N), by reducing the percentage of O2 and increasing the percentage of N so that the resultant mixed-gas has a partial pressure of O2 approximating that of specified altitudes. This technique was used to generate normobaric hypoxic equivalents of 8,000, 12,000, and 14,000 feet above MSL in a group of 36 volunteers with a mTBI history and an equal number of controls matched on the basis of age, gender, tobacco smoking consumption, weight, height, and body mass index. Short-term visual memory was tested using the Matching to Sample (M2S) subtest of the BrainCheckers analog of the Automated Neuropsychological Assessment Metrics. Although there were no significant differences in M2S performance between the two groups of subjects at MSL, with increased altitude, the mTBI group performance was significantly worse than that of the control group. When the subjects were returned to MSL, the difference disappeared. This finding suggests that the “hypoxic challenge” paradigm developed here has potential clinical utility for assessing the effects of mTBI in individuals who appear asymptomatic under normal conditions. PMID:23641232

  8. Critical swelling of fluctuating capsules

    NASA Astrophysics Data System (ADS)

    Diamant, Haim; Haleva, Emir

    2009-03-01

    In many natural transport processes the solute molecules to be transported are encapsulated in semipermeable, flexible membrane vesicles of micron size. We study the swelling of such fluctuating capsules, as the number of encapsulated particles is increased, or the concentration of the outer solution is decreased. The approach to the maximum volume-to-area ratio and the associated buildup of membrane tension involve a continuous phase transition and follow universal scaling laws. The criticality and its features are model-independent, arising solely from the interplay between volume and surface degrees of freedom.ootnotetextE. Haleva and H. Diamant, Phys. Rev. Lett. 101, 078104 (2008).

  9. Scrotal Swelling in the Neonate

    PubMed Central

    Basta, Amaya M.; Courtier, Jesse; Phelps, Andrew; Copp, Hillary L.; MacKenzie, John D.

    2016-01-01

    Discovery of scrotal swelling in a neonate can be a source of anxiety for parents, clinicians, and sonologists alike. This pictorial essay provides a focused review of commonly encountered scrotal masses and mimics specific to the neonatal setting. Although malignancy is a concern, it is very uncommon, as most neonatal scrotal masses are benign. Key discriminating features and management options are highlighted to improve the radiologist’s ability to diagnose neonatal scrotal conditions and guide treatment decisions. Neonatal scrotal processes ranging from common to uncommon will be discussed. PMID:25715370

  10. Biophysics: Unfolding the brain

    NASA Astrophysics Data System (ADS)

    Kuhl, Ellen

    2016-06-01

    The folded surface of the human brain, although striking, continues to evade understanding. Experiments with swelling gels now fuel the notion that brain folding is modulated by physical forces, and not by genetic, biological or chemical events alone.

  11. Evaluating changes in brain vasculature of murine embryos in utero due to maternal alcohol consumption using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Raghunathan, Raksha; Wu, Chen; Singh, Manmohan; Liu, Chih-Hao; Miranda, Rajesh C.; Larin, Kirill V.

    2017-04-01

    Fetal Alcohol Syndrome (FAS) refers to the broad spectrum of developmental and behavioral effects caused due to prenatal alcohol exposure (PAE). Wide range of abnormalities vary depending on the amount of alcohol consumed and the period of consumption during gestation. PAE during early stages of pregnancy is very common. However a large number of women continue to consume alcohol even during the second trimester, a critical period for fetal neurogenesis and angiogenesis. Optical coherence tomography (OCT) has shown to be extremely useful in embryonic imaging. Our previous work showed that OCT is capable of quantitative assessment of ventriculomegaly caused by maternal alcohol consumption. Although structural changes and changes in blood flow in the fetal brain after maternal alcohol consumption have been studied, acute vasculature changes are not well documented. Speckle variance OCT (SVOCT), is a functional extension of OCT that has been used to study vasculature development in embryos. We use SVOCT, to detect vasculature changes in the embryonic brain in utero, minutes after maternal alcohol consumption.

  12. Brain-Derived Neurotrophic Factor Serum Levels and Hippocampal Volume in Mild Cognitive Impairment and Dementia due to Alzheimer Disease

    PubMed Central

    Borba, Ericksen Mielle; Duarte, Juliana Avila; Bristot, Giovana; Scotton, Ellen; Camozzato, Ana Luiza; Chaves, Márcia Lorena Fagundes

    2016-01-01

    Background/Aims Hippocampal atrophy is a recognized biomarker of Alzheimer disease (AD) pathology. Serum brain-derived neurotrophic factor (BDNF) reduction has been associated with neurodegeneration. We aimed to evaluate BDNF serum levels and hippocampal volume in clinical AD (dementia and mild cognitive impairment [MCI]). Methods Participants were 10 patients with MCI and 13 with dementia due to AD as well as 10 healthy controls. BDNF serum levels were determined by ELISA and volumetric measures with NeuroQuant®. Results MCI and dementia patients presented lower BDNF serum levels than healthy participants; dementia patients presented a smaller hippocampal volume than MCI patients and healthy participants. Discussion The findings support that the decrease in BDNF might start before the establishment of neuronal injury expressed by the hippocampal reduction. PMID:28101102

  13. Swell Sleeves for Testing Explosive Devices

    NASA Technical Reports Server (NTRS)

    Hinkel, Todd J.; Dean, Richard J.; Hohmann, Carl W.; Hacker, Scott C.; Harrington, Douglas W.; Bacak, James W.

    2003-01-01

    A method of testing explosive and pyrotechnic devices involves exploding the devices inside swell sleeves. Swell sleeves have been used previously for measuring forces. In the present method, they are used to obtain quantitative indications of the energy released in explosions of the devices under test. A swell sleeve is basically a thick-walled, hollow metal cylinder threaded at one end to accept a threaded surface on a device to be tested (see Figure 1). Once the device has been tightly threaded in place in the swell sleeve, the device-and-swell-sleeve assembly is placed in a test fixture, then the device is detonated. After the explosion, the assembly is removed from the test fixture and placed in a coordinate-measuring machine for measurement of the diameter of the swell sleeve as a function of axial position. For each axial position, the original diameter of the sleeve is subtracted from the diameter of the sleeve as swollen by the explosion to obtain the diametral swelling as a function of axial position (see Figure 2). The amount of swelling is taken as a measure of the energy released in the explosion. The amount of swelling can be compared to a standard amount of swelling to determine whether the pyrotechnic device functioned as specified.

  14. The Economic Burden of Traumatic Brain Injury Due to Fatal Traffic Accidents in Shahid Rajaei Trauma Hospital, Shiraz, Iran

    PubMed Central

    Kavosi, Zahra; Jafari, Abdosaleh; Hatam, Nahid; Enaami, Meysam

    2015-01-01

    Background: Traumatic Brain Injuries (TBIs) as a result of traffic accidents are one of the major causes of deaths, which lead to the loss of individuals’ productive and working years of life. Objectives: This study aimed to calculate the economic burden of traumatic brain injuries in fatal crashes at Shahid Rajaei Trauma Hospital, Shiraz, Iran for a period of five years. Patients and Methods: In this descriptive, cross-sectional study the population included people who had died as a result of TBIs during 2009 to 2013 in Shiraz Shahid Rajaei Trauma Hospital. Cost and demographic data were obtained from the participants’ medical records using data gathering forms, and some other information was also collected via telephone calls to the victims’ families. Economic burden of TBIs due to traffic accidents, which led to death, was estimated using the human capital as direct costs of treatment, and the number of potential years of life lost and lost productivity as indirect costs. Results: Deaths resulting from TBIs due to traffic accidents in Shiraz imposed 6.2 billion Rials (511000 USD) of hospital costs, 6390 potential years of life lost, and 506 billion Rials (20 million USD) of productivity lost. In the present study, the mean age of the individuals who died was 38.4 ± 19.41 and the productivity lost per capita was 1.8 billion Rials (73000 USD). Conclusions: The findings of this study indicated that the economic burden of TBIs was high in fatal accidents in Fars Province so that it was equivalent to 0.00011% of Iran’s Gross Domestic Product (GDP) in 2013. Therefore, more attention has to be paid to the rules to prevent the fatal accidents. PMID:25834791

  15. Swelling-induced surface instabilities in growing poroelastic polymer networks

    NASA Astrophysics Data System (ADS)

    Hennessy, Matthew G.; Vitale, Alessandra; Cabral, Joao T.; Matar, Omar K.

    2016-11-01

    The swelling that occurs when a deformable polymer network absorbs solvent can generate large compressive stresses which, in turn, can lead to a rich variety of surface instabilities. In this talk, we will discuss recent experiments by our group which suggest that the growth of a polymer network by photopolymerisation and the onset of swelling-induced surface instabilities can simultaneously occur and drive the self-assembly of complex three-dimensional structures. In addition, we will present a theoretical model of photopolymersation that captures the growth, swelling, and mechanical response of the polymer network. The model is based on an Eulerian formulation of nonlinear poroelasticity. The transport of monomer is described by a generalisation of Darcy's law that accounts for flow due to gradients in the pressure and composition. A combination of asymptotic analysis and finite-element simulations is used to explore the coupling between growth and instability as well as the resulting surface morphologies.

  16. Tamoxifen does not inhibit the swell activated chloride channel in human neutrophils during the respiratory burst

    SciTech Connect

    Ahluwalia, Jatinder

    2008-10-31

    Effective functioning of neutrophils relies upon electron translocation through the NADPH oxidase (NOX). The electron current generated (I{sub e}) by the neutrophil NADPH oxidase is electrogenic and rapidly depolarises the membrane potential in activated human neutrophils. Swelling activated chloride channels have been demonstrated in part to counteract the depolarisation generated by the NADPH oxidase I{sub e}. In the present study, the effects of inhibitors of swell activated chloride channels on ROS production and on the swelling activated chloride conductance was investigated in activated human neutrophils. Tamoxifen (10 {mu}M), a specific inhibitor for swell activated chloride channels in neutrophils, completely inhibited both the PMA and FMLP stimulated respiratory burst. This inhibition of the neutrophil respiratory burst was not due to the blocking effect of tamoxifen on the swelling activated chloride conductance in these cells. These results demonstrate that a tamoxifen insensitive swell activated chloride channel has important significance during the neutrophil respiratory burst.

  17. Neck swelling with renal stone.

    PubMed

    Khan, M K; Taous, A; Sultana, S Z; Sharif, A; Hossain, M M; Mostafa, G; Hussain, M A; Azim, M A; Siddique, M A

    2010-10-01

    Since the advent of screening of calcium and imaging techniques (CT and MRI), hyperparathyroidism has been detected with increasing frequency. Although in the past, most patients present with severe bone and renal diseases, a large number of patients are asymptomatic. Number of parathyroid glands and their ectopic locations in individuals are the problem of its management. Parathyroid adenoma or hyperplasia may be a part of Multiple Endocrine neoplasia type II. This is the story of a boy of 18 years who had got admitted in the department of Otolaryngology, Mymensingh Medical College Hospital with the complaints of a neck swelling, abdominal discomfort, inability to walk, frequency of micturation for almost same duration of 1 year. After search, hypercalcaemia, bilateral renal stone, raised parathormone level and enlarged one parathyroid gland in lower pole of left thyroid lobe was identified. Clinically it was diagnosed as parathyroid adenoma which was proved histologically after surgical excision. Many controversies still exist regarding the treatment policy of parathyroid adenoma.

  18. Swelling soils in the road structures

    NASA Astrophysics Data System (ADS)

    Pruška, Jan; Šedivý, Miroslav

    2017-09-01

    There are frequent problems with the soil swelling in the road construction in the past time. This phenomenon is known for decades. This situation is notably given by insufficient knowledge of this problem and difficulties with input parameters describing the swelling process. The paper in the first part proposed regression relations to predict swelling pressure, time of swelling and swelling strain for different initial water contents for soils and improvement soils. The relations were developed by using artificial neural network and QCExpert Professional software (on the data from site investigations by GeoTec-GS, a.s. and experimental data from CTU in Prague). The advantage of the relations is based on using the results of the basic soil tests (plasticity index, consistency index and colloidal activity) as input parameters. The authors inform the technical public with their current knowledge of the problems with the soil swelling on the motorway in the second part of the paper.

  19. Description of Extrudate Swell for Polymer Nanocomposites

    PubMed Central

    Wang, Kejian

    2010-01-01

    Extrudate swell is often observed to be weakened in nanocomposites compared to the pure polymer matrix. A theory quantifying this would be significant either for optimum processing or for understanding their viscoelasticity. A unified extrudate swell correlation with material properties and capillary parameters was suggested for polymer melt and their nanocomposites when considering the reservoir entry effect. More importantly, it was the first to find that the composite swell ratio can be the matrix swell ratio multiplied by the concentration shift factor, which is similar to the dynamic moduli expression for composites. The factor is a function of the shear field (stress or shear rate), filler content, filler internal structure and the surface state as well as the matrix properties. Several sets of swell data for nanocomposites were chosen from publications to test the new theories. The proposed quantitative model displayed good fit for the five kinds of nanocomposites, which verified the rationality of the swell theory for nanocomposites.

  20. Macroscopic Potentials for Charged Swelling Porous Media

    NASA Astrophysics Data System (ADS)

    Bennethum, L. S.

    2011-12-01

    Here we discuss the macroscopic potentials that induce bulk fluid flow through swelling porous materials. Swelling porous media such as expansive soils, food stuff, biotissue, and swelling polymers have complex microstructure such as a possibly charged solid surface and a large liquid-solid interfacial area density causing the solid-liquid interaction to affect macroscopic behavior. Here we discuss the macroscopic pressures and chemical potentials that produce flow within the framework of hybrid mixture theory.

  1. Prediction of swelling rocks strain in tunneling

    NASA Astrophysics Data System (ADS)

    Parsapour, D.; Fahimifar, A.

    2016-05-01

    Swelling deformations leading to convergence of tunnels may result in significant difficulties during the construction, in particular for long term use of tunnels. By extracting an experimental based explicit analytical solution for formulating swelling strains as a function of time and stress, swelling strains are predicted from the beginning of excavation and during the service life of tunnel. Results obtained from the analytical model show a proper agreement with experimental results. This closed-form solution has been implemented within a numerical program using the finite element method for predicting time-dependent swelling strain around tunnels. Evaluating effects of swelling parameters on time-dependent strains and tunnel shape on swelling behavior around the tunnel according to this analytical solution is considered. The ground-support interaction and consequent swelling effect on the induced forces in tunnel lining is considered too. Effect of delay in lining installation on swelling pressure which acting on the lining and its structural integrity, is also evaluated. A MATLAB code of " SRAP" is prepared and applied to calculate all swelling analysis around tunnels based on analytical solution.

  2. Eosinophilic Granuloma Presenting as Palatal Swelling

    PubMed Central

    Babu, B. Balaji; Nadendla, Lakshmi Kavitha; Madki, Pooja

    2016-01-01

    Swellings involving palate can be challenging to diagnose for the clinician as they have wide range of origin which can result from developmental, inflammatory, reactive or a neoplastic process. The clinical presentation of these swellings is similar and difficult to differentiate from each other. So it is important to take proper history from the patient and subject the patient to appropriate laboratory and radiographic investigations and finally biopsy is mandatory for accurate diagnosis. Thus, this article highlights on various common palatal swellings, their clinical presentation, and differential diagnosis helpful for proper diagnosis of swellings associated with palate. PMID:27891486

  3. Swelling of cattle heel horn by urine.

    PubMed

    Gregory, N G

    2004-03-01

    To understand the likely mechanisms responsible for heel horn softening when cattle stand in their own effluent. To examine the effectiveness of some footbath chemicals in preventing heel horn softening. Shavings from the heels of cattle were used in a laboratory test to examine the swelling effects of cow urine, urea, sulphide and ammonia. Formalin, glutaraldehyde, glyoxal, zinc sulphate, copper sulphate, alum, tannic acid and a compound containing nitrocellulose plus nylon, were compared for their ability to prevent swelling in heel shavings induced by urea plus 2-mercaptoethanol. Cow urine caused heel horn to swell. Urea caused swelling at concentrations normally found in cow urine. Sulphide caused swelling at concentrations normally found in cow slurry. Low concentrations of ammonia solution also resulted in swelling. Formalin and glutaraldehyde prevented swelling induced by high concentrations of urea plus 2-mercaptoethanol. Copper sulphate had a moderate anti-swelling effect. Zinc sulphate, alum, tannic acid, and nitrocellulose plus nylon were relatively ineffective in preventing swelling. Cow urine can cause degradation of heel horn in cattle feet. The chemical agents that cause this could be urea, sulphide anions and ammonia. Degradation by urine can be prevented by pretreating heel horn with formalin. Glutaraldehyde may be an effective noncarcinogenic alternative to formalin.

  4. Using compression hosiery to prevent rebound swelling.

    PubMed

    Todd, Marie

    2015-10-01

    The management of chronic oedema often consists of a programme of compression bandaging to reduce swelling and improve skin changes and limb shape, followed by patient self-care management in compression hosiery. Occasionally, patients experience rebound swelling and require further episodes of bandaging. In such cases, a thorough assessment of the causes of the rebound swelling should be carried out so that they can be eliminated. By evidencing three case studies, this article demonstrates that Haddenham Custom Goldpunkt garments can be useful in preventing rebound swelling, making it a cost- and resource-effective method of managing stubborn chronic oedema and lymphoedema.

  5. Specific absorption rate variation in a brain phantom due to exposure by a 3G mobile phone: problems in dosimetry.

    PubMed

    Behari, J; Nirala, Jay Prakash

    2013-12-01

    A specific absorption rate (SAR) measurements system has been developed for compliance testing of personal mobile phone in a brain phantom material contained in a Perspex box. The volume of the box has been chosen corresponding to the volume of a small rat and illuminated by a 3G mobile phone frequency (1718.5 MHz), and the emitted radiation directed toward brain phantom .The induced fields in the phantom material are measured. Set up to lift the plane carrying the mobile phone is run by a pulley whose motion is controlled by a stepper motor. The platform is made to move at a pre-determined rate of 2 degrees per min limited up to 20 degrees. The measured data for induced fields in various locations are used to compute corresponding SAR values and inter comparison obtained. These data are also compared with those when the mobile phone is placed horizontally with respect to the position of the animal. The SAR data is also experimentally obtained by measuring a rise in temperature due to this mobile exposures and data compared with those obtained in the previous set. To seek a comparison with the safety criteria same set of measurements are performed in 10 g phantom material contained in a cubical box. These results are higher than those obtained with the knowledge of induced field measurements. It is concluded that SAR values are sensitive to the angular position of the moving platform and are well below the safety criteria prescribed for human exposure. The data are suggestive of having a fresh look to understand the mode of electromagnetic field -bio interaction.

  6. Recent Research in Behind-Armor Blunt Trauma and Traumatic Brain Injury

    DTIC Science & Technology

    2014-02-01

    injury to the brain can be a product of explosive blast TBI, due to increase in intracranial pressure from pressure loading, and coup-contrecoup... intracranial pressure at the trauma point and decreased (contrecoup) pressure at the opposite side of the cerebrum. In addition to the brain striking the...difficult to detect, these injuries include DAI, ischemic brain injury, and swelling that can lead to increased intracranial pressure . DAI can result

  7. Obstructive hydrocephalus due to CNS toxocariasis.

    PubMed

    Choi, Jae-Hwan; Cho, Jae-Wook; Lee, Jae-Hyeok; Lee, Sang Weon; Kim, Hak-Jin; Choi, Kwang-Dong

    2013-06-15

    A 46-year-old man developed intermittent headache, diplopia, and visual obscuration for two months. Funduscopic examination showed optic disk swelling in both eyes. Brain MRI exhibited hydrocephalus and leptomeningeal enhancement at the prepontine cistern, left cerebellopontine angle cistern and bilateral cerebral hemisphere, and hemosiderin deposition along the cerebellar folia. CSF analysis revealed an elevated opening pressure with xanthochromic appearance and small amount of red blood cells. Antibody titer against Toxocariasis using ELISA was elevated both in blood and CSF. Obstructive hydrocephalus and hemosiderin deposition in this case may result from the active inflammatory process due to CNS toxocariasis within the subarachnoid space.

  8. Hygro-thermal mechanical behavior of Nafion during constrained swelling

    NASA Astrophysics Data System (ADS)

    Silberstein, Meredith N.; Boyce, Mary C.

    Durability is a major limitation of current proton exchange membrane fuel cells. Mechanical stress due to hygro-thermal cycling is one failure mechanism of the polymer electrolyte membrane. In previous work the cyclic rate, temperature, and hydration dependent elastic-viscoplastic mechanical behavior of Nafion has been extensively investigated in uniaxial and biaxial tension, serving as a data basis and means of validation for a three-dimensional constitutive model. Here, the important effect of loading via constrained swelling is studied. Specifically, two types of loading are investigated: partially constrained swelling via a bimaterial swelling test and hygro-thermal cycling within a fuel cell. The bimaterial swelling conditions are examined via experiments in conjunction with modeling. Nafion/GDL bimaterial strips were hydrated and observed to curl significantly with the membrane on the convex side due to the large Nafion hygro-expansion coefficient. Upon drying the bimaterial strips developed a slight reverse curvature with the membrane on the concave side due to the plastic deformation which had occurred in the membrane during hydration. Finite element simulations utilizing the Nafion constitutive model successfully predicted the behavior during hydration and drying, providing insight on the constrained swelling physics and the ability of the model to predict such events. Simulations of in situ fuel cell hygro-thermal cycling are performed via a simplified two-dimensional fuel cell model. The simulation results confirm the finding of other studies that a tensile stress develops in the membrane during drying. Further, a concentration of negative hydrostatic pressure is found to develop just inside the channel region in the dried state supporting the theory of hygro-thermal driven mechanical stresses causing pinhole formation in the channel. The amplitude of the pressure cycling is found to be large and sensitive to both hygro-thermal ramp time and hold time

  9. Changes in Brain Metallome/Metabolome Pattern due to a Single i.v. Injection of Manganese in Rats

    PubMed Central

    Neth, Katharina; Lucio, Marianna; Walker, Alesia; Zorn, Julia; Schmitt-Kopplin, Philippe; Michalke, Bernhard

    2015-01-01

    Exposure to high concentrations of Manganese (Mn) is known to potentially induce an accumulation in the brain, leading to a Parkinson related disease, called manganism. Versatile mechanisms of Mn-induced brain injury are discussed, with inactivation of mitochondrial defense against oxidative stress being a major one. So far, studies indicate that the main Mn-species entering the brain are low molecular mass (LMM) compounds such as Mn-citrate. Applying a single low dose MnCl2 injection in rats, we observed alterations in Mn-species pattern within the brain by analysis of aqueous brain extracts by size-exclusion chromatography—inductively coupled plasma mass spectrometry (SEC-ICP-MS). Additionally, electrospray ionization—ion cyclotron resonance-Fourier transform-mass spectrometry (ESI-ICR/FT-MS) measurement of methanolic brain extracts revealed a comprehensive analysis of changes in brain metabolisms after the single MnCl2 injection. Major alterations were observed for amino acid, fatty acid, glutathione, glucose and purine/pyrimidine metabolism. The power of this metabolomic approach is the broad and detailed overview of affected brain metabolisms. We also correlated results from the metallomic investigations (Mn concentrations and Mn-species in brain) with the findings from metabolomics. This strategy might help to unravel the role of different Mn-species during Mn-induced alterations in brain metabolism. PMID:26383269

  10. Changes in Brain Metallome/Metabolome Pattern due to a Single i.v. Injection of Manganese in Rats.

    PubMed

    Neth, Katharina; Lucio, Marianna; Walker, Alesia; Zorn, Julia; Schmitt-Kopplin, Philippe; Michalke, Bernhard

    2015-01-01

    Exposure to high concentrations of Manganese (Mn) is known to potentially induce an accumulation in the brain, leading to a Parkinson related disease, called manganism. Versatile mechanisms of Mn-induced brain injury are discussed, with inactivation of mitochondrial defense against oxidative stress being a major one. So far, studies indicate that the main Mn-species entering the brain are low molecular mass (LMM) compounds such as Mn-citrate. Applying a single low dose MnCl2 injection in rats, we observed alterations in Mn-species pattern within the brain by analysis of aqueous brain extracts by size-exclusion chromatography--inductively coupled plasma mass spectrometry (SEC-ICP-MS). Additionally, electrospray ionization--ion cyclotron resonance-Fourier transform-mass spectrometry (ESI-ICR/FT-MS) measurement of methanolic brain extracts revealed a comprehensive analysis of changes in brain metabolisms after the single MnCl2 injection. Major alterations were observed for amino acid, fatty acid, glutathione, glucose and purine/pyrimidine metabolism. The power of this metabolomic approach is the broad and detailed overview of affected brain metabolisms. We also correlated results from the metallomic investigations (Mn concentrations and Mn-species in brain) with the findings from metabolomics. This strategy might help to unravel the role of different Mn-species during Mn-induced alterations in brain metabolism.

  11. Bilateral parotid swelling: a radiological review

    PubMed Central

    Gadodia, A; Bhalla, A S; Sharma, R; Thakar, A; Parshad, R

    2011-01-01

    Bilateral parotid swelling is not an uncommon occurrence and may pose a challenge for clinicians and radiologists. Numerous causes of bilateral parotid swellings have been identified. The purpose of this pictorial review is to display this wide array with a focus on multimodality approach. PMID:21960397

  12. Growth hormone deficiency due to traumatic brain injury in a patient with X-linked congenital adrenal hypoplasia.

    PubMed

    Engiz, Ozlem; Ozön, Alev; Riepe, Felix; Alikaşifoğlu, Ayfer; Gönç, Nazli; Kandemir, Nurgün

    2010-01-01

    X-linked adrenal hypoplasia congenita (AHC) is characterized by primary adrenal insufficiency and is frequently associated with hypogonadotropic hypogonadism (HH). The production of other pituitary hormones (adrenocorticotropic hormone [ACTH], growth hormone [GH], thyroid-stimulating hormone [TSH], and prolactin [PRL]) is usually normal. Mutations of the DAX-1 gene have been reported in patients with AHC and HH. We present a 13-year-old male patient with AHC caused by a nonsense mutation in the DAX-1 gene who developed GH deficiency following head trauma. He showed signs of adrenal insufficiency at the age of 23 months, and glucocorticoid and mineralocorticoid treatment was started. His parents reported head trauma due to a traffic accident at the age of 21 months. Adrenal computed tomography revealed hypoplasia of the left and agenesis of the right adrenal gland. Decreased growth rate was noted at the age of 12.5 years while receiving hydrocortisone 15 mg/m2/day. His height was 139.9 cm (-1.46 SD), body weight was 54.9 kg, pubic hair was Tanner stage 1, and testis size was 3 ml. His bone age was 7 years. His gonadotropin (follicle-stimulating hormone [FSH], luteinizing hormone [LH]) and testosterone levels were prepubertal. The evaluation of GH/insulin-like growth factor-1 (IGF-1) secretion at the age of 13 years revealed GH deficiency. Pituitary magnetic resonance imaging demonstrated a hypoplastic hypophysis (< 2.5 mm) and a normal infundibulum. GH treatment (0.73 IU/kg/week) was started. This paper reports a patient with genetically confirmed AHC demonstrating GH deficiency possibly due to a previous head trauma. Complete pituitary evaluation should be performed in any child who has survived severe traumatic brain injury.

  13. Somato-axodendritic release of oxytocin into the brain due to calcium amplification is essential for social memory.

    PubMed

    Higashida, Haruhiro

    2016-07-01

    Oxytocin (OT) is released into the brain from the cell soma, axons, and dendrites of neurosecretory cells in the hypothalamus. Locally released OT can activate OT receptors, form inositol-1,4,5-trisphosphate and elevate intracellular free calcium (Ca(2+)) concentrations [(Ca(2+)) i ] in self and neighboring neurons in the hypothalamus, resulting in further OT release: i.e., autocrine or paracrine systems of OT-induced OT release. CD38-dependent cyclic ADP-ribose (cADPR) is also involved in this autoregulation by elevating [Ca(2+)] i via Ca(2+) mobilization through ryanodine receptors on intracellular Ca(2+) pools that are sensitive to both Ca(2+) and cADPR. In addition, it has recently been reported that heat stimulation and hyperthermia enhance [Ca(2+)] i increases by Ca(2+) influx, probably through TRPM2 cation channels, suggesting that cADPR and TRPM2 molecules act as Ca(2+) signal amplifiers. Thus, OT release is not simply due to depolarization-secretion coupling. Both of these molecules play critical roles not only during labor and milk ejection in reproductive females, but also during social behavior in daily life in both genders. This was clearly demonstrated in CD38 knockout mice in that social behavior was impaired by reduction of [Ca(2+)] i elevation and subsequent OT secretion. Evidence for the associations of CD38 with social behavior and psychiatric disorder is discussed, especially in subjects with autism spectrum disorder.

  14. Endocrine response to acute changes of brain blood flow due to lower body negative pressure in man.

    PubMed

    Tigranian, R A; Jarullin, K; Kalita, N; Simonov, L; Vigas, M

    1985-06-01

    The decrease of brain flow due to lower body negative pressure (LBNP) was used to study the role of cerebral glucopenia in the activation of anterior pituitary function in 10 young healthy men. During LBNP with a maximum negative pressure of--50 mm Hg the changes in heart rate, blood pressure cerebral blood flow (with the aid of rheoencephalography) and electrocardiogram were recorded and the levels of hGH, ACTH, hPRL, insulin and cortisol were measured with the aid of radioimmunoassay. During the first investigation an infusion of 20% glucose (1 g per min for first 30 min and 0.5 g per min for next 30 min) was used, while during the second investigation (one week later) the infusion of saline was applied. It was found that the infusion of glucose prevented the increase of hGH which was observed only during the infusion of saline. No differences in the level of ACTH, cortisol and hPRL were observed between the investigations with glucose and saline infusion. The increased level of insulin was related to the level of glucose during the infusion, while no changes were found during saline infusion. It was suggested that the increase of hGH level during LBNP resulted from glucopenia in cerebral tissue.

  15. Psychological and adjustment problems due to acquired brain lesions in pediatric patients: a comparison of vascular, infectious, and other origins.

    PubMed

    Pastore, Valentina; Galbiati, Susanna; Villa, Federica; Colombo, Katia; Recla, Monica; Adduci, Annarita; Avantaggiato, Paolo; Bardoni, Alessandra; Strazzer, Sandra

    2014-12-01

    The aim of this study was to describe psychological, behavioral, and adjustment problems in children and adolescents with acquired brain lesions of different origins. Three groups of patients with acquired brain lesions (15 patients with infectious origin, 37 with vascular origin, and 15 with other origin), ranging in age from 4 to 18 years, received a psychological evaluation, including the Child Behavior Checklist for ages 4 to 18 and the Vineland Adaptive Behavior Scale. About half of the total sample (47.8%) showed psychological problems. Difficulties varied according to the cause of the brain lesions. The most problematic patients were children with brain lesions of infectious origin, whereas children with brain lesions of vascular origin scored lower on most of the Child Behavior Checklist scales. The authors conclude that psychological and behavioral difficulties are very common among school-aged children with acquired brain lesions, and their relevance and impact must necessarily be considered. © The Author(s) 2014.

  16. In vivo magnetic resonance imaging investigating the development of experimental brain metastases due to triple negative breast cancer.

    PubMed

    Hamilton, Amanda M; Foster, Paula J

    2017-02-01

    Triple negative breast cancer (TNBC), when associated with poor outcome, is aggressive in nature with a high incidence of brain metastasis and the shortest median overall patient survival after brain metastasis development compared to all other breast cancer subtypes. As therapies that control primary cancer and extracranial metastatic sites improve, the incidence of brain metastases is increasing and the management of patients with breast cancer brain metastases continues to be a significant clinical challenge. Mouse models have been developed to permit in depth evaluation of breast cancer metastasis to the brain. In this study, we compare the efficiency and metastatic potential of two experimental mouse models of TNBC. Longitudinal MRI analysis and end point histology were used to quantify initial cell arrest as well as the number and volume of metastases that developed in mouse brain over time. We showed significant differences in MRI appearance, tumor progression and model efficiency between the syngeneic 4T1-BR5 model and the xenogeneic 231-BR model. Since TNBC does not respond to many standard breast cancer treatments and TNBC brain metastases lack effective targeted therapies, these preclinical TNBC models represent invaluable tools for the assessment of novel systemic therapeutic approaches. Further pursuits of therapeutics designed to bypass the blood tumor barrier and permit access to the brain parenchyma and metastatic cells within the brain will be paramount in the fight to control and treat lethal metastatic cancer.

  17. Stress response of bovine artery and rat brain tissue due to combined translational shear and fixed unconfined compression

    NASA Astrophysics Data System (ADS)

    Leahy, Lauren

    During trauma resulting from impacts and blast waves, sinusoidal waves permeate the brain and cranial arterial tissue, both non-homogeneous biological tissues with high fluid contents. The experimental shear stress response to sinusoidal translational shear deformation at 1 Hz and 25% strain amplitude and either 0% or 33% compression is compared for rat brain tissue and bovine aortic tissue. Both tissues exhibit Mullins effect in shear. Harmonic wavelet decomposition, a novel application to the mechanical response of these tissues, shows significant 1 Hz and 3 Hz components. The 3 Hz component magnitude in brain tissue, which is much larger than in aortic tissue, may correlate to interstitial fluid induced drag forces that decrease on subsequent cycles perhaps because of damage resulting in easier fluid movement. The fluid may cause the quasiperiodic, viscoelastic behavior of brain tissue. The mechanical response differences under impact may cause shear damage between arterial and brain connections.

  18. Fractional cable equation for general geometry: A model of axons with swellings and anomalous diffusion

    NASA Astrophysics Data System (ADS)

    López-Sánchez, Erick J.; Romero, Juan M.; Yépez-Martínez, Huitzilin

    2017-09-01

    Different experimental studies have reported anomalous diffusion in brain tissues and notably this anomalous diffusion is expressed through fractional derivatives. Axons are important to understand neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, and Parkinson's disease. Indeed, abnormal accumulation of proteins and organelles in axons is a hallmark of these diseases. The diffusion in the axons can become anomalous as a result of this abnormality. In this case the voltage propagation in axons is affected. Another hallmark of different neurodegenerative diseases is given by discrete swellings along the axon. In order to model the voltage propagation in axons with anomalous diffusion and swellings, in this paper we propose a fractional cable equation for a general geometry. This generalized equation depends on fractional parameters and geometric quantities such as the curvature and torsion of the cable. For a cable with a constant radius we show that the voltage decreases when the fractional effect increases. In cables with swellings we find that when the fractional effect or the swelling radius increases, the voltage decreases. Similar behavior is obtained when the number of swellings and the fractional effect increase. Moreover, we find that when the radius swelling (or the number of swellings) and the fractional effect increase at the same time, the voltage dramatically decreases.

  19. Effect of swelling pressure on local volume change in unsaturated sand-bentonite buffer material

    SciTech Connect

    Shooshpasha, I.; Mohamed, A.M.O.; Yong, R.N.; Onofrei, C.

    1996-08-01

    This study was designed to investigate the effect of swelling pressure on local volume changes in unsaturated sand-bentonite based buffer material used in a nuclear fuel waste disposal vault. A laboratory mixture of sodium bentonite and graded silica sand in equal proportion by dry weight was used in both ambient and elevated temperatures experiments. At high water content locations within the tested specimens, the density was reduced by 3.57% from its initial values due to swelling. The swelling pressure as a function of distance was calculated by 4 different models. The calculated results have indicated that the density distribution within the specimen is affected by swelling potential distribution. The calculated swelling pressure values vary as a function of water content, reaching 1 MPa at the source of water intake, i.e., at high water content zone, and 2 MPa at the heater side, i.e., at low water content zone.

  20. The effect of low dose rate irradiation on the swelling of 12% cold-worked 316 stainless steel.

    SciTech Connect

    Allen, T. R.

    1999-03-02

    In pressurized water reactors (PWRs), stainless steel components are irradiated at temperatures that may reach 400 C due to gamma heating. If large amounts of swelling (>10%) occur in these reactor internals, significant swelling related embrittlement may occur. Although fast reactor studies indicate that swelling should be insignificant at PWR temperatures, the low dose rate conditions experienced by PWR components may possibly lead to significant swelling. To address these issues, JNC and ANL have collaborated to analyze swelling in 316 stainless steel, irradiated in the EBR-II reactor at temperatures from 376-444 C, at dose rates between 4.9 x 10{sup {minus}8} and 5.8 x 10{sup {minus}7} dpa/s, and to doses of 56 dpa. For these irradiation conditions, the swelling decreases markedly at temperatures less than approximately 386 C, with the extrapolated swelling at 100 dpa being around 3%. For temperatures greater than 386 C, the swelling extrapolated to 100 dpa is around 9%. For a factor of two difference in dose rate, no statistically significant effect of dose rate on swelling was seen. For the range of dose rates analyzed, the swelling measurements do not support significant (>10%) swelling of 316 stainless steel in PWRs.

  1. A rare cause of lateral facial swelling

    PubMed Central

    Mohanty, Sujata; Gulati, Ujjwal; Vandana; Singh, Sapna

    2014-01-01

    A case of chronic, recurrent and asymptomatic facial swelling in a young male is presented. Swelling extended from lower midface to upper lateral neck and right commissure to anterior massetric border. History, clinical signs and symptoms and examination pointed towards the benign nature of the swelling. Fine-needle aspiration cytology tapered the diagnostic possibilities to a salivary cyst or pseudocyst. Ultrasonography identified the lesion to contain echogenic fluid with irregular borders. “Tail sign” was absent on contrast magnetic resonance imaging, excluding the involvement of the sublingual gland. Surgical excision of the lesion was done along with submandibular gland as both were in continuity via a bottle-neck tract. Final histopathological diagnosis was that of the submandibular gland extravasation phenomenon. As per the best of our knowledge, it is the first case report of a submandibular gland extravasation causing swelling in a retrograde direction onto the face. PMID:25593883

  2. Foot Swelling during Air Travel: A Concern?

    MedlinePlus

    ... The most likely culprit is inactivity during a flight. Sitting with your feet on the floor for ... soft tissues. To relieve foot swelling during a flight: Wear loosefitting clothing Take a short walk every ...

  3. Swells of the East China Sea

    NASA Astrophysics Data System (ADS)

    Tao, Aifeng; Yan, Jin; Pei, Ye; Zheng, Jinhai; Mori, Nobuhito

    2017-08-01

    Over the past few decades, an increasing number of marine activities have been conducted in the East China Sea, including the construction of various marine structures and the passage of large ships. Marine safety issues are paramount and are becoming more important with respect to the likely increase in size of ocean waves in relation to global climate change and associated typhoons. In addition, swells also can be very dangerous because they induce the resonance of floating structures, including ships. This study focuses on an investigation of swells in the East China Sea and uses hindcast data for waves over the past 5 years in a numerical model, WAVEWATCH III (WW3), together with historical climate data. The numerical calculation domain covers the entire North West Pacific. Next, swells are separated and analyzed using simulated wave fields, and both the characteristics and generation mechanisms of swells are investigated.

  4. Swelling of lignites in organic solvents

    SciTech Connect

    R.G. Makitra; D.V. Bryk

    2008-10-15

    Data on the swelling of Turkish lignites can be summarized using linear multiparameter equations that take into account various properties of solvents. Factors responsible for the amounts of absorbed solvents are the basicity and cohesion energy density of the solvents.

  5. Inhibitors of the mitochondrial permeability transition reduce ammonia-induced cell swelling in cultured astrocytes.

    PubMed

    Reddy, Pichili V B; Rama Rao, Kakulavarapu V; Norenberg, Michael D

    2009-09-01

    Ammonia is the principal neurotoxin implicated in the pathogenesis of hepatic encephalopathy, and astrocytes are the neural cells predominantly affected in this condition. Astrocyte swelling (cytotoxic edema) represents a critical component of the brain edema in acute form of hepatic encephalopathy (acute liver failure, ALF). Although mechanisms of astrocyte swelling by ammonia are not completely understood, cultured astrocytes exposed to pathophysiological levels of ammonia develop the mitochondrial permeability transition (mPT), a process that was shown to result in astrocyte swelling. Cyclosporin A (CsA), a traditional inhibitor of the mPT, was previously shown to completely block ammonia-induced astrocyte swelling in culture. However, the efficacy of CsA to protect cytotoxic brain edema in ALF is problematic because it poorly crosses the blood-brain barrier, which is relatively intact in ALF. We therefore examined the effect of agents that block the mPT but are also known to cross the blood-brain barrier, including pyruvate, magnesium, minocycline, and trifluoperazine on the ammonia-induced mPT, as well as cell swelling. Cultured astrocytes exposed to ammonia for 24 hr displayed the mPT as demonstrated by a CsA-sensitive dissipation of the mitochondrial inner membrane potential. Pyruvate, minocycline, magnesium, and trifluoperazine significantly blocked the ammonia-induced mPT. Ammonia resulted in a significant increase in cell volume, which was blocked by the above-mentioned agents to a variable degree. A regression analysis indicated a high correlation between the effectiveness of reducing the mPT and cell swelling. Our data suggest that all these agents have therapeutic potential in mitigating brain edema in ALF.

  6. Alkaline Ceramidase 3 Deficiency Results in Purkinje Cell Degeneration and Cerebellar Ataxia Due to Dyshomeostasis of Sphingolipids in the Brain

    PubMed Central

    Preston, Chet; Wang, Louis; Yi, Jae Kyo; Lin, Chih-Li; Sun, Wei; Spyropoulos, Demetri D.; Rhee, Soyoung; Li, Mingsong; Zhou, Jie; Ge, Shaoyu; Zhang, Guofeng; Snider, Ashley J.; Hannun, Yusuf A.; Obeid, Lina M.; Mao, Cungui

    2015-01-01

    Dyshomeostasis of both ceramides and sphingosine-1-phosphate (S1P) in the brain has been implicated in aging-associated neurodegenerative disorders in humans. However, mechanisms that maintain the homeostasis of these bioactive sphingolipids in the brain remain unclear. Mouse alkaline ceramidase 3 (Acer3), which preferentially catalyzes the hydrolysis of C18:1-ceramide, a major unsaturated long-chain ceramide species in the brain, is upregulated with age in the mouse brain. Acer3 knockout causes an age-dependent accumulation of various ceramides and C18:1-monohexosylceramide and abolishes the age-related increase in the levels of sphingosine and S1P in the brain; thereby resulting in Purkinje cell degeneration in the cerebellum and deficits in motor coordination and balance. Our results indicate that Acer3 plays critically protective roles in controlling the homeostasis of various sphingolipids, including ceramides, sphingosine, S1P, and certain complex sphingolipids in the brain and protects Purkinje cells from premature degeneration. PMID:26474409

  7. Validity of semi-quantitative scale for brain MRI in unilateral cerebral palsy due to periventricular white matter lesions: Relationship with hand sensorimotor function and structural connectivity.

    PubMed

    Fiori, Simona; Guzzetta, Andrea; Pannek, Kerstin; Ware, Robert S; Rossi, Giuseppe; Klingels, Katrijn; Feys, Hilde; Coulthard, Alan; Cioni, Giovanni; Rose, Stephen; Boyd, Roslyn N

    2015-01-01

    To provide first evidence of construct validity of a semi-quantitative scale for brain structural MRI (sqMRI scale) in children with unilateral cerebral palsy (UCP) secondary to periventricular white matter (PWM) lesions, by examining the relationship with hand sensorimotor function and whole brain structural connectivity. Cross-sectional study of 50 children with UCP due to PWM lesions using 3 T (MRI), diffusion MRI and assessment of hand sensorimotor function. We explored the relationship of lobar, hemispheric and global scores on the sqMRI scale, with fractional anisotropy (FA), as a measure of brain white matter microstructure, and with hand sensorimotor measures (Assisting Hand Assessment, AHA; Jebsen-Taylor Test for Hand Function, JTTHF; Melbourne Assessment of Unilateral Upper Limb Function, MUUL; stereognosis; 2-point discrimination). Lobar and hemispheric scores on the sqMRI scale contralateral to the clinical side of hemiplegia correlated with sensorimotor paretic hand function measures and FA of a number of brain structural connections, including connections of brain areas involved in motor control (postcentral, precentral and paracentral gyri in the parietal lobe). More severe lesions correlated with lower sensorimotor performance, with the posterior limb of internal capsule score being the strongest contributor to impaired hand function. The sqMRI scale demonstrates first evidence of construct validity against impaired motor and sensory function measures and brain structural connectivity in a cohort of children with UCP due to PWM lesions. More severe lesions correlated with poorer paretic hand sensorimotor function and impaired structural connectivity in the hemisphere contralateral to the clinical side of hemiplegia. The quantitative structural MRI scoring may be a useful clinical tool for studying brain structure-function relationships but requires further validation in other populations of CP.

  8. Validity of semi-quantitative scale for brain MRI in unilateral cerebral palsy due to periventricular white matter lesions: Relationship with hand sensorimotor function and structural connectivity

    PubMed Central

    Fiori, Simona; Guzzetta, Andrea; Pannek, Kerstin; Ware, Robert S.; Rossi, Giuseppe; Klingels, Katrijn; Feys, Hilde; Coulthard, Alan; Cioni, Giovanni; Rose, Stephen; Boyd, Roslyn N.

    2015-01-01

    Aim To provide first evidence of construct validity of a semi-quantitative scale for brain structural MRI (sqMRI scale) in children with unilateral cerebral palsy (UCP) secondary to periventricular white matter (PWM) lesions, by examining the relationship with hand sensorimotor function and whole brain structural connectivity. Methods Cross-sectional study of 50 children with UCP due to PWM lesions using 3 T (MRI), diffusion MRI and assessment of hand sensorimotor function. We explored the relationship of lobar, hemispheric and global scores on the sqMRI scale, with fractional anisotropy (FA), as a measure of brain white matter microstructure, and with hand sensorimotor measures (Assisting Hand Assessment, AHA; Jebsen–Taylor Test for Hand Function, JTTHF; Melbourne Assessment of Unilateral Upper Limb Function, MUUL; stereognosis; 2-point discrimination). Results Lobar and hemispheric scores on the sqMRI scale contralateral to the clinical side of hemiplegia correlated with sensorimotor paretic hand function measures and FA of a number of brain structural connections, including connections of brain areas involved in motor control (postcentral, precentral and paracentral gyri in the parietal lobe). More severe lesions correlated with lower sensorimotor performance, with the posterior limb of internal capsule score being the strongest contributor to impaired hand function. Conclusion The sqMRI scale demonstrates first evidence of construct validity against impaired motor and sensory function measures and brain structural connectivity in a cohort of children with UCP due to PWM lesions. More severe lesions correlated with poorer paretic hand sensorimotor function and impaired structural connectivity in the hemisphere contralateral to the clinical side of hemiplegia. The quantitative structural MRI scoring may be a useful clinical tool for studying brain structure–function relationships but requires further validation in other populations of CP. PMID:26106533

  9. Brain energy metabolism spurns fatty acids as fuel due to their inherent mitotoxicity and potential capacity to unleash neurodegeneration.

    PubMed

    Schönfeld, Peter; Reiser, Georg

    2017-03-30

    The brain uses long-chain fatty acids (LCFAs) to a negligible extent as fuel for the mitochondrial energy generation, in contrast to other tissues that also demand high energy. Besides this generally accepted view, some studies using cultured neural cells or whole brain indicate a moderately active mitochondrial β-oxidation. Here, we corroborate the conclusion that brain mitochondria are unable to oxidize fatty acids. In contrast, the combustion of liver-derived ketone bodies by neural cells is long-known. Furthermore, new insights indicate the use of odd-numbered medium-chain fatty acids as valuable source for maintaining the level of intermediates of the citric acid cycle in brain mitochondria. Non-esterified LCFAs or their activated forms exert a large variety of harmful side-effects on mitochondria, such as enhancing the mitochondrial ROS generation in distinct steps of the β-oxidation and therefore potentially increasing oxidative stress. Hence, the question arises: Why do in brain energy metabolism mitochondria selectively spurn LCFAs as energy source? The most likely answer are the relatively higher content of peroxidation-sensitive polyunsaturated fatty acids and, the low antioxidative defense in brain tissue. There are two remarkable peroxisomal defects, one relating to α-oxidation of phytanic acid and the other to uptake of very long-chain fatty acids (VLCFAs) which lead to pathologically high tissue levels of such fatty acids. Both, the accumulation of phytanic acid and that of VLCFAs give an enlightening insight into harmful activities of fatty acids on neural cells, which possibly explain why evolution has prevented brain mitochondria from the equipment of with significant β-oxidation enzymatic capacity.

  10. The excessively small ventricle on computed axial tomography of the brain.

    PubMed

    Hahn, F J; Schapiro, R L

    1976-01-01

    Computed axial tomography has made it possible to observe excessively small ventricles in a variety of disorders of the CNS. This finding is presumably due to non-specific and diffuse swelling of brain parenchyma, and is illustrated in cases of trauma, neoplasm, encephalitis, pseudotumor cerebri, metabolic disorder, and probable dilantin effect. It is likely that other causes will be encountered in the future.

  11. Unexpected death in persons with symptomatic epilepsy due to glial brain tumors: a report of two cases and review of the literature.

    PubMed

    Büttner, A; Gall, C; Mall, G; Weis, S

    1999-03-15

    Two cases of unexpected death in persons with epileptic seizures due to a brain tumor are presented which encompassed an astrocytoma WHO grade II and an anaplastic astrocytoma WHO grade III. A 35-year-old man was found somnolent and disoriented at home. A computed tomography (CT) scan revealed a tumor of the right frontal lobe suggestive for an oligodendroglioma. During an angiographic examination the patient experienced an epileptic seizure. Some weeks later, the man was found dead in front of his house with a fresh bite mark of the tongue. Neuropathological examination revealed an astrocytoma WHO grade II of the right frontal lobe. A 47-year-old man plunged into a swimming-pool and was found submerged some minutes later. After resuscitation he survived comatose for 8 days but finally died due to severe hypoxic brain damage. He had been operated on a brain tumor of the temporal lobe 1 year before the accident. Neuropathological examination revealed residual tumor tissue at the operation site corresponding to an anaplastic astrocytoma WHO grade III. Although rare, death in persons with epileptic seizures due to brain tumors is an important mechanism of death encountered by the forensic pathologist.

  12. Radiation preparation and swelling behavior of sodium carboxymethyl cellulose hydrogels

    NASA Astrophysics Data System (ADS)

    Liu, Pengfei; Zhai, Maolin; Li, Jiuqiang; Peng, Jing; Wu, Jilan

    2002-03-01

    Sodium carboxymethyl cellulose (CMC) is a kind of degraded polymer under γ-irradiation. However, in this work, it has been found that CMC crosslinks partially to form hydrogel by radiation technique at more than 20% CMC aqueous solution. The gel fraction increases with the dose. The crosslinking reaction of CMC is promoted in the presence of N 2 or N 2O due to the increase of free radicals on CMC backbone, but gel fraction of CMC hydrogel is not high (<40%). Some important values related to this kind of new CMC hydrogel synthesized under different conditions, such as radiation yield of crosslinking G( x), gelation dose Rg, number average molecular weight of network Mc were calculated according to the Charlesby-Pinner equation. The results indicated that although crosslinked CMC hydrogel could be prepared by radiation method, the rate of radiation degradation of CMC was faster than that of radiation crosslinking due to the character of CMC itself. Swelling dynamics of CMC hydrogel and its swelling behavior at different conditions, such as acidic, basic, inorganic salt as well as temperature were also investigated. Strong acidity, strong basicity, small amount of inorganic salts and lower temperature can reduce swelling ratio.

  13. The wind sea and swell waves climate in the Nordic seas

    NASA Astrophysics Data System (ADS)

    Semedo, Alvaro; Vettor, Roberto; Breivik, Øyvind; Sterl, Andreas; Reistad, Magnar; Soares, Carlos Guedes; Lima, Daniela

    2015-02-01

    A detailed climatology of wind sea and swell waves in the Nordic Seas (North Sea, Norwegian Sea, and Barents Sea), based on the high-resolution reanalysis NORA10, developed by the Norwegian Meteorological Institute, is presented. The higher resolution of the wind forcing fields, and the wave model (10 km in both cases), along with the inclusion of the bottom effect, allowed a better description of the wind sea and swell features, compared to previous global studies. The spatial patterns of the swell-dominated regional wave fields are shown to be different from the open ocean, due to coastal geometry, fetch dimensions, and island sheltering. Nevertheless, swell waves are still more prevalent and carry more energy in the Nordic Seas, with the exception of the North Sea. The influence of the North Atlantic Oscillation on the winter regional wind sea and swell patterns is also presented. The analysis of the decadal trends of wind sea and swell heights during the NORA10 period (1958-2001) shows that the long-term trends of the total significant wave height (SWH) in the Nordic Seas are mostly due to swell and to the wave propagation effect.

  14. An unusual cause of pre-auricular swelling.

    PubMed

    Harris, A T; Bhatti, I; Bajaj, Y; Smelt, G J C

    2010-03-01

    To present an interesting cause of pre-auricular swelling. We report the case of a 39-year-old woman who presented to the ENT department as an emergency with swelling in the left pre-auricular region. The patient had recently travelled to Central America, where the botfly is endemic. On examination, there was a raised, indurated area with a central orifice. A botfly larva was suspected. The larva was suffocated with paraffin paste, allowing removal without remnants being retained. Suffocation of botfly larvae is favoured to surgical removal, due to the possibility of larval remnants being retained and acting as a nidus for infection. The increasing frequency of exotic travel means doctors need to be more aware of tropical medicine.

  15. Estimates of the eigenvalues of operator arising in swelling pressure model

    SciTech Connect

    Kanguzhin, Baltabek; Zhapsarbayeva, Lyailya

    2016-08-10

    Swelling pressures from materials confined by structures can cause structural deformations and instability. Due to the complexity of interactions between expansive solid and solid-liquid equilibrium, the forces exerting on retaining structures from swelling are highly nonlinear. This work is our initial attempt to study a simplistic spectral problem based on the Euler-elastic beam theory and some simplistic swelling pressure model. In this work estimates of the eigenvalues of some initial/boundary value problem for nonlinear Euler-elastic beam equation are obtained.

  16. Morphing of geometric composites via residual swelling.

    PubMed

    Pezzulla, Matteo; Shillig, Steven A; Nardinocchi, Paola; Holmes, Douglas P

    2015-08-07

    Understanding and controlling the shape of thin, soft objects has been the focus of significant research efforts among physicists, biologists, and engineers in the last decade. These studies aim to utilize advanced materials in novel, adaptive ways such as fabricating smart actuators or mimicking living tissues. Here, we present the controlled growth-like morphing of 2D sheets into 3D shapes by preparing geometric composite structures that deform by residual swelling. The morphing of these geometric composites is dictated by both swelling and geometry, with diffusion controlling the swelling-induced actuation, and geometric confinement dictating the structure's deformed shape. Building on a simple mechanical analog, we present an analytical model that quantitatively describes how the Gaussian and mean curvatures of a thin disk are affected by the interplay among geometry, mechanics, and swelling. This model is in excellent agreement with our experiments and numerics. We show that the dynamics of residual swelling is dictated by a competition between two characteristic diffusive length scales governed by geometry. Our results provide the first 2D analog of Timoshenko's classical formula for the thermal bending of bimetallic beams - our generalization explains how the Gaussian curvature of a 2D geometric composite is affected by geometry and elasticity. The understanding conferred by these results suggests that the controlled shaping of geometric composites may provide a simple complement to traditional manufacturing techniques.

  17. Swelling and Contraction of Corn Mitochondria 1

    PubMed Central

    Stoner, C. D.; Hanson, J. B.

    1966-01-01

    A survey has been made of the properties of corn mitochondria in swelling and contraction. The mitochondria swell spontaneously in KCl but not in sucrose. Aged mitochondria will swell rapidly in sucrose if treated with citrate or EDTA. Swelling does not impair oxidative phosphorylation if bovine serum albumin is present. Contraction can be maintained or initiated with ATP + Mg or an oxidizable substrate, contraction being more rapid with the substrate. Magnesium is not required for substrate powered contraction. Contraction powered by ATP is accompanied by the release of phosphate. Oligomycin inhibits both ATP-powered contraction and the release of phosphate. However, it does not affect substrate-powered contraction. Substrate powered contraction is inhibited by electron-transport inhibitors. The uncoupler, carbonyl cyanide m-chlorophenyl hydrazone, accelerates swelling and inhibits both ATP-and substrate-powered contraction. However, the concentrations required are well in excess of those required to produce uncoupling and to accelerate adenosine triphosphatase; the concentrations required inhibit respiration in a phosphorylating medium. Phosphate is a very effective inhibitor of succinate-powered contraction. Neither oligomycin nor Mg affects the phosphate inhibition. Phosphate is less inhibitory with the ATP-powered contraction. The results are discussed in terms of a hypothesis that contraction is associated with a nonphosphorylated high energy intermediate of oxidative phosphorylation. Images PMID:16656248

  18. Impact of swelling characteristics on the permselective ...

    EPA Pesticide Factsheets

    The removal of water from organic solvents and biofuels, including lower alcohols (i.e., methanol, ethanol, propanol, and butanol), is necessary for the production, blending, and reuse of those organic compounds. Water forms an azeotrope with many hydrophilic solvents, complicating the separation of water/solvent mixtures. The use of water-selective membranes in a pervaporation or vapor permeation process enables the removal of water from the solvents, even when an azeotrope is present. Common hydrophilic polymer membranes often swell in water, resulting in permeabilities and selectivities that are dependent on the water content of the feed mixture. Recent work has shown the benefit of overcoating a hydrophilic water-permselective membrane with a non-swelling perfluoropolymer film [1,2]. The perfluoropolymer layer reduces the activity of water the hydrophilic polymer layer experiences, thereby reducing swelling in that layer and increasing the water selectivity of the multi-layer membrane relative to the selectivity of the base hydrophilic polymer, usually at the expense of permeability. In this work, the effect of overcoating the hydrophilic layer with polymer films of various swelling characteristics was modelled. Top layers that swell in the solvent offer some advantages, particularly with regard to the water permeance of the multi-layer composite. 1. Huang, Y.; Baker, R. W.; Wijmans, J. G. Perfluoro-coated hydrophilic membranes with improved selectivity. In

  19. Swelling, mechanical and friction properties of PVA/PVP hydrogels after swelling in osmotic pressure solution.

    PubMed

    Shi, Yan; Xiong, Dangsheng; Liu, Yuntong; Wang, Nan; Zhao, Xiaoduo

    2016-08-01

    The potential of polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) hydrogels as articular cartilage replacements was in vitro evaluated by using a macromolecule-based solution to mimic the osmotic environment of cartilage tissue. The effects of osmotic pressure solution on the morphology, crystallinity, swelling, mechanical and friction properties of PVA/PVP hydrogels were investigated by swelling them in non-osmotic and osmotic pressure solutions. The results demonstrated that swelling ratio and equilibrium water content were greatly reduced by swelling in osmotic solution, and the swelling process was found to present pseudo-Fickian diffusion character. The crystallization degree of hydrogels after swelling in osmotic solution increased more significantly when it compared with that in non-osmotic solution. After swelling in osmotic solution for 28days, the compressive tangent modulus and storage modulus of hydrogels were significantly increased, and the low friction coefficient was reduced. However, after swelling in the non-osmotic solution, the compressive tangent modulus and friction coefficient of hydrogels were comparable with those of as-prepared hydrogels. The better material properties of hydrogels in vivo than in vitro evaluation demonstrated their potential application in cartilage replacement. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Swelling of p H -sensitive hydrogels

    NASA Astrophysics Data System (ADS)

    Drozdov, A. D.; deClaville Christiansen, J.

    2015-02-01

    A model is derived for the elastic response of polyelectrolyte gels subjected to unconstrained and constrained swelling. A gel is treated as a three-phase medium consisting of a solid phase (polymer network), solvent (water), and solutes (mobile ions). Transport of solvent and solutes is modeled as their diffusion through the network accelerated by an electric field formed by ions and accompanied by chemical reactions (dissociation of functional groups attached to the chains). Constitutive equations (including the van't Hoff law for ionic pressure and the Henderson-Hasselbach equation for ionization of chains) are derived by means of the free energy imbalance inequality. Good agreement is demonstrated between equilibrium swelling diagrams on several pH-sensitive gels and results of simulation. It is revealed that swelling of polyelectrolyte gels is driven by electrostatic repulsion of bound charges, whereas the effect of ionic pressure is of secondary importance.

  1. Mechanisms affecting swelling in alloys with precipitates

    SciTech Connect

    Mansur, L.K.; Haynes, M.R.; Lee, E.H.

    1980-01-01

    In alloys under irradiation many mechanisms exist that couple phase instability to cavity swelling. These are compounded with the more familiar mechanisms associated with point defect behavior and the evolution of microstructure. The mechanisms may be classified according to three modes of operation. Some affect cavity swelling directly by cavity-precipitate particle association, others operate indirectly by precipitate-induced changes in sinks other than cavities and finally there are mechanisms that are mediated by precipitate-induced changes in the host matrix. The physics of one mechanism of each type is developed in detail and the results compared where possible to experimental measurements. In particular, we develop the theory necessary to treat the effects on swelling of precipitation-induced changes in overall sink density; precipitation-induced changes in point defect trapping by solute depletion and creation of precipitate particle-matrix interfacial trap sites.

  2. Swelling of pH-sensitive hydrogels.

    PubMed

    Drozdov, A D; deClaville Christiansen, J

    2015-02-01

    A model is derived for the elastic response of polyelectrolyte gels subjected to unconstrained and constrained swelling. A gel is treated as a three-phase medium consisting of a solid phase (polymer network), solvent (water), and solutes (mobile ions). Transport of solvent and solutes is modeled as their diffusion through the network accelerated by an electric field formed by ions and accompanied by chemical reactions (dissociation of functional groups attached to the chains). Constitutive equations (including the van't Hoff law for ionic pressure and the Henderson-Hasselbach equation for ionization of chains) are derived by means of the free energy imbalance inequality. Good agreement is demonstrated between equilibrium swelling diagrams on several pH-sensitive gels and results of simulation. It is revealed that swelling of polyelectrolyte gels is driven by electrostatic repulsion of bound charges, whereas the effect of ionic pressure is of secondary importance.

  3. Treatment of persistent post-concussion syndrome due to mild traumatic brain injury: current status and future directions.

    PubMed

    Hadanny, Amir; Efrati, Shai

    2016-08-01

    Persistent post-concussion syndrome caused by mild traumatic brain injury has become a major cause of morbidity and poor quality of life. Unlike the acute care of concussion, there is no consensus for treatment of chronic symptoms. Moreover, most of the pharmacologic and non-pharmacologic treatments have failed to demonstrate significant efficacy on both the clinical symptoms as well as the pathophysiologic cascade responsible for the permanent brain injury. This article reviews the pathophysiology of PCS, the diagnostic tools and criteria, the current available treatments including pharmacotherapy and different cognitive rehabilitation programs, and promising new treatment directions. A most promising new direction is the use of hyperbaric oxygen therapy, which targets the basic pathological processes responsible for post-concussion symptoms; it is discussed here in depth.

  4. BRAIN ABSCESS DUE TO Staphylococcus aureus OF CRYPTOGENIC SOURCE IN AN HIV-1 INFECTED PATIENT IN USE OF ANTIRETROVIRAL THERAPY

    PubMed Central

    de OLIVEIRA, Anna Paula Romero; PAPPALARDO, Mara Cristina; DANTAS, Daniel; LINS, Diogo; VIDAL, José Ernesto

    2016-01-01

    The spectrum of neurological complications associated with human immunodeficiency virus type 1 (HIV-1) infection is broad. The most frequent etiologies include primary diseases (caused by HIV itself) or secondary diseases (opportunistic infections or neoplasms). Despite these conditions, HIV-infected patients are susceptible to other infections observed in patients without HIV infection. Here we report a rare case of a brain abscess caused by Staphylococcus aureus in an HIV-infected patient. After drainage of the abscess and treatment with oxacilin, the patient had a favorable outcome. This case reinforces the importance of a timely neurosurgical procedure that supported adequate management of an unusual cause of expansive brain lesions in HIV-1 infected patients. PMID:27074328

  5. Acute care alternate-level-of-care days due to delayed discharge for traumatic and non-traumatic brain injuries.

    PubMed

    Amy, Chen; Zagorski, Brandon; Chan, Vincy; Parsons, Daria; Vander Laan, Rika; Colantonio, Angela

    2012-05-01

    Alternate-level-of-care (ALC) days represent hospital beds that are taken up by patients who would more appropriately be cared for in other settings. ALC days have been found to be costly and may result in worse functional outcomes, reduced motor skills and longer lengths of stay in rehabilitation. This study examines the factors that are associated with acute care ALC days among patients with acquired brain injury (ABI). We used the Discharge Abstract Database to identify patients with ABI using International Classification of Disease-10 codes. From fiscal years 2007/08 to 2009/10, 17.5% of patients with traumatic and 14% of patients with non-traumatic brain injury had at least one ALC day. Significant predictors include having a psychiatric co-morbidity, increasing age and length of stay in acute care. These findings can inform planning for care of people with ABI in a publicly funded healthcare system.

  6. Acute Care Alternate-Level-of-Care Days Due to Delayed Discharge for Traumatic and Non-Traumatic Brain Injuries

    PubMed Central

    Amy, Chen; Zagorski, Brandon; Chan, Vincy; Parsons, Daria; Vander Laan, Rika; Colantonio, Angela

    2012-01-01

    Alternate-level-of-care (ALC) days represent hospital beds that are taken up by patients who would more appropriately be cared for in other settings. ALC days have been found to be costly and may result in worse functional outcomes, reduced motor skills and longer lengths of stay in rehabilitation. This study examines the factors that are associated with acute care ALC days among patients with acquired brain injury (ABI). We used the Discharge Abstract Database to identify patients with ABI using International Classification of Disease-10 codes. From fiscal years 2007/08 to 2009/10, 17.5% of patients with traumatic and 14% of patients with non-traumatic brain injury had at least one ALC day. Significant predictors include having a psychiatric co-morbidity, increasing age and length of stay in acute care. These findings can inform planning for care of people with ABI in a publicly funded healthcare system. PMID:23634162

  7. Cyclic swelling as a phenomenon inherent to biodegradable polyesters.

    PubMed

    Dittrich, Milan; Snejdrova, Eva

    2014-11-01

    The aim of this study is to evaluate and describe the phenomenon and mechanism of the spontaneous cyclic swelling and deswelling of linear and branched aliphatic polyesters in the aqueous medium. The fluctuation of gel volume in one or several cycles as an inherent property of biodegradable and bioerodible materials has not yet been described. We have observed the process at linear and branched polyesters of aliphatic α-hydroxy acids. The period of duration of cycles was in order of hours to days, as influenced by the size of the bodies ranging from 25 to 1000 mg, the temperature in the range of 7°C-42°C, ionic strength, and pH value. The results demonstrated that swelling is accompanied by hydrolysis of ester bonds with the development of small water-soluble osmotically active molecules. After reaching a higher degree of swelling, the obstruction effect of the gel decreases and the diffusion of soluble degradation products from the body to the environment prevails. A decrease in osmotic pressure inside the body and a decrease in the hydrophilic character of the gel matrix result in deswelling by a collapse of the structure, probably due to hydrophobic interactions of nonpolar polyester chains.

  8. Comparing the Effect of Botulinum Toxin Type B Injection at Different Dosages for Patient with Drooling due to Brain Lesion

    PubMed Central

    Park, Hee Dong; Park, Sang Jun; Choi, Yong Min

    2012-01-01

    Objective To investigate Botulinum toxin type B (BNT-B) injection's effect and duration depending on dose for patients with brain lesion. Method Twenty one patients with brain lesion and severe drooling were included and divided into three groups. All patients received conventional dysphagia therapy. Group A patients (n=7) received an injection of 1,500 units and group B patients (n=7) received an injection of 2,500 units of BNT-B in submandibular gland under ultrasound guidance. Group C patients (n=7) received conventional dysphagia therapy. Saliva secretion was assessed quantitatively at baseline and at weeks 1, 2, 4, 8, and 12. The severity and frequency of drooling was assessed using the Drooling Quotient (DQ) by patients and/or caregivers. Results Group A and B reported a distinct improvement of the symptoms within 2 weeks after BNT-B injection. Compared to the baseline, the mean amount of saliva decreased significantly throughout the study. However, there was no meaningful difference between the two groups. The greatest reductions were achieved at 2 weeks and lasted up to 8 weeks after BNT-B injection. Group C did not show any differences. Conclusion Local injection of 1,500 units of BNT-B into salivary glands under ultrasonic guidance proved to be a safe and effective dose for drooling in patient with brain lesion, as did 2,500 units. PMID:23342318

  9. Protective effects of melatonin and vitamin E in brain damage due to gamma radiation: an experimental study.

    PubMed

    Erol, Fatih S; Topsakal, Cahide; Ozveren, M Faik; Kaplan, Metin; Ilhan, Nevin; Ozercan, I Hanifi; Yildiz, Oguz G

    2004-01-01

    Gamma radiation is known to cause serious damage in the brain, and many agents have been used for neuroprotection. In this study, lipid peroxidation levels and histopathological changes in brain tissues of whole-body irradiated rats with likely radiation injury were compared to those with melatonin and vitamin E protection. Forty rats in four equal groups were used. The control group received neither radiation nor medication. The remaining groups received doses of 720 cGy in two equal fractions 12 h apart. The second group received radiation but no medication, the third received radiation plus 100 mg/kg per day of vitamin E i.p., and the fourth received radiation plus 100 mg/kg per day of melatonin i.p. over 5 days. On the 10th postoperative day, all the rats were decapitated and specimens from parietal cortices were analyzed for tissue malondialdehyde (MDA) levels and histopathological changes. Increases in MDA were relatively well prevented by melatonin treatment but less so with vitamin E therapy. On histopathological examination, melatonin significantly reduced the rates of edema, necrosis, and neuronal degeneration, whereas vitamin E reduced only necrosis. Neither substance was capable of preventing vasodilatation. In conclusion, melatonin may be useful in preventing the pathological changes of secondary brain damage as a result of free oxygen radicals generated by irradiation.

  10. Swelling pressure of a divalent-rich bentonite: Diffuse double-layer theory revisited

    NASA Astrophysics Data System (ADS)

    Schanz, Tom; Tripathy, Snehasis

    2009-05-01

    Physicochemical forces are responsible for the swelling pressure development in saturated bentonites. In this paper, the swelling pressures of several compacted bentonite specimens for a range of dry density of 1.10-1.73 Mg/m3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na+ ions. The theoretical swelling pressure-dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-layer theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m3, a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-layer theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m3, whereas at higher dry densities the use of the equations was found to be limited.

  11. Swelling effect actuation of shape-memory polymer: mechanism and demonstration

    NASA Astrophysics Data System (ADS)

    Lu, Haibao; Leng, Jinsong; Liu, Yanju; Du, Shanyi

    2009-03-01

    Recently, there is increasing interest in triggering shape recovery of shape-memory polymers (SMPs) by novel inductive effect. In this paper, many hard works have been carried out to make SMP induced while along with swelling effect. Based on the Free-volume theory, Rubber Elasticity Theory and Mooney-Rivlin Equation, it is theoretically and experimentally demonstrated the feasibility of SMP activated by swelling effect. The mechanism behind it is solvent acting as plasticizer, to reduce the glass transition temperature (Tg) and melting temperature (Tm) of polymers, make them softer and more flexible, facilitating the diffusion of the molecules to polymer chains, and then separating them. In addition to this physical action, the intermolecular interactions among the chains are weakened, because interactions are hindered at the points where the plasticizer is located. Finally, the Dynamic mechanical analysis (DMA), FTIR study and glass transition temperature measurement tests were used to exemplify the feasibility of SMP driven by swelling effect. And it is qualitatively identified the role of swelling effect playing in influencing the transition temperature. Swelling effect occurs due to the interaction between macromolecules and solvent molecules, leading to free volume of polymeric chains increasing (namely the flexibility of polymer chains increasing), resulting in the Tg decreasing. All above mentioned investigation can be used to confirm that the shape recovery is induced by swelling effect. This actuation almost is applicable for all the SMP and SMP composite, as the swelling theory is almost applicable for all the polymeric materials.

  12. NMR imaging and cryoporometry of swelling clays

    NASA Astrophysics Data System (ADS)

    Dvinskikh, Sergey V.; Szutkowski, Kosma; Petrov, Oleg V.; Furó, István.

    2010-05-01

    Compacted bentonite clay is currently attracting attention as a promising "self-sealing" buffer material to build in-ground barriers for the encapsulation of radioactive waste. It is expected to fill up the space between waste canister and surrounding ground by swelling and thus delay flow and migration from the host rock to the canister. In environmental sciences, evaluation and understanding of the swelling properties of pre-compacted clay are of uttermost importance for designing such buffers. Major goal of present study was to provide, in a non-invasive manner, a quantitative measure of bentonite distribution in extended samples during different physical processes in an aqueous environment such as swelling, dissolution, and sedimentation on the time scale from minutes to years. The propagation of the swelling front during clay expansion depending on the geometry of the confining space was also studied. Magnetic resonance imaging and nuclear magnetic resonance spectroscopy were adapted and used as main experimental techniques. With this approach, spatially resolved movement of the clay/water interface as well as clay particle distributions in gel phase can be monitored [1]. Bulk samples with swelling in a vertical tube and in a horizontal channel were investigated and clay content distribution profiles in the concentration range over five orders of magnitude and with sub-millimetre spatial resolution were obtained. Expansion rates for bulk swelling and swelling in narrow slits were compared. For sodium-exchanged montmorillonite in contact with de-ionised water, we observed a remarkable acceleration of expansion as compared to that obtained in the bulk. To characterize the porosity of the clay a cryoporometric study [2] has been performed. Our results have important implications to waste repository designs and for the assessment of its long-term performance. Further research exploring clay-water interaction over a wide variety of clay composition and water ionic

  13. PFAPA with facial swelling- a new association?

    PubMed

    Khodaghalian, B; Tewary, K K; Narchi, H

    2013-05-01

    PFAPA (periodic fever, apthous stomatitis, pharyngitis, cervical adenitis) is a rare condition of unknown cause affecting children. Although the exact etiology is unknown, inflammatory, immunological or genetic causes have been suggested. The diagnosis is made by exclusion of other causes of periodic fever. Although management is essentially symptomatic, single corticosteroid dose, tonsillectomy and Cimetidine has been shown to be associated with resolution of symptoms. Although abdominal pain and genital ulcers have been reported in association with PFAPA, unilateral transient facial swelling has not been previously reported. The authors present a hitherto unreported association of PFAPA with recurrent episodes of unilateral facial swelling.

  14. Neural responses of rat cortical layers due to infrared neural modulation and photoablation of thalamocortical brain slices

    NASA Astrophysics Data System (ADS)

    Jenkins, J. Logan; Kao, Chris C.; Cayce, Jonathan M.; Mahadevan-Jansen, Anita; Jansen, E. Duco

    2017-02-01

    Infrared neural modulation (INM) is a label-free method for eliciting neural activity with high spatial selectivity in mammalian models. While there has been an emphasis on INM research towards applications in the peripheral nervous system and the central nervous system (CNS), the biophysical mechanisms by which INM occurs remains largely unresolved. In the rat CNS, INM has been shown to elicit and inhibit neural activity, evoke calcium signals that are dependent on glutamate transients and astrocytes, and modulate inhibitory GABA currents. So far, in vivo experiments have been restricted to layers I and II of the rat cortex which consists mainly of astrocytes, inhibitory neurons, and dendrites from deeper excitatory neurons owing to strong absorption of light in these layers. Deeper cortical layers (III-VI) have vastly different cell type composition, consisting predominantly of excitatory neurons which can be targeted for therapies such as deep brain stimulation. The neural responses to infrared light of deeper cortical cells have not been well defined. Acute thalamocortical brain slices will allow us to analyze the effects of INS on various components of the cortex, including different cortical layers and cell populations. In this study, we present the use of photoablation with an erbium:YAG laser to reduce the thickness of the dead cell zone near the cutting surface of brain slices. This technique will allow for more optical energy to reach living cells, which should contribute the successful transduction of pulsed infrared light to neural activity. In the future, INM-induced neural responses will lead to a finer characterization of the parameter space for the neuromodulation of different cortical cell types and may contribute to understanding the cell populations that are important for allowing optical stimulation of neurons in the CNS.

  15. [Attention system functions and their relationship with self-reported health in patients with brain damage due to tumor].

    PubMed

    Egorov, V N; Razumnikova, O M; Perfil'ev, A M; Stupak, V V

    2015-01-01

    To compare parameters of attention in healthy people and patients with neoplasms in different regions of the cerebral cortex and to evaluate quality of life (QoL) indices with regard to impairment of different attention systems. Twenty patients with oncological lesions of the brain (mean age 56.5±8.8 years) who did not undergo surgery were studied. Tumor localization was confirmed using contrast-enhanced computed tomography, the tumor type was histologically verified. A control group included 18 healthy people matched for age, sex and education level. To determine attention system functions, we developed a computed version of the Attention Network Test. Error rate and reaction time for correct responses to the target stimulus, displayed along with neutral, congruent and incongruent signals, were the indicators of the efficacy of selective processes. QoL indices were assessed using SF-36 health survey questionnaire. The readiness to respond to incoming stimuli was mostly impaired in patients with brain tumors. Efficacy of executive attention, assessed as the increase in the number of errors in selection of visual stimuli, was decreased while temporary parameters of the functions of this system were not changed in patients compared to controls. The SF-36 total score was stable in patients with marked reduction in scores on the Role and Emotional Functioning scales. The most severe health impairment measured on the SF-36 scales of role/social emotional functioning and viability was recorded in patients with the lesions of frontal cortical areas compared to temporal/parietal areas. The relationship between SF-36 Health self-rating and attention systems was found. This finding puts the question of the importance of attention characteristics and QoL for survival prognosis of patients with brain tumors.

  16. Dart model for irradiation-induced swelling of dispersion fuel elements including aluminum-fuel interaction

    SciTech Connect

    Rest, J.; Hofman, G.L.

    1997-06-01

    The Dispersion Analysis Research Tool (DART) contains models for fission-gas induced fuel swelling, interaction of fuel with the matrix aluminum, resultant reaction-product swelling, and calculation of the stress gradient within the fuel particle. The effects of an aluminide shell on fuel particle swelling are evaluated. Validation of the model is demonstrated by a comparison of DART calculations of fuel swelling of U{sub 3}SiAl-Al and U{sub 3}Si{sub 2}-Al for various dispersion fuel element designs with the data. DART results are compared with data for fuel swelling Of U{sub 3}SiAl-Al in plate, tube, and rod configurations as a function of fission density. Plate and tube calculations were performed at a constant fuel temperature of 373 K and 518 K, respectively. An irradiation temperature of 518 K results in a calculated aluminide layer thickness for the Russian tube that is in the center of the measured range (16 {mu}m). Rod calculations were performed with a temperature gradient across the rod characterized by surface and central temperatures of 373 K and 423 K, respectively. The effective yield stress of irradiated Al matrix material and the aluminide was determined by comparing the results of DART calculations with postirradiation immersion volume measurement of U{sub 3}SiAl plates. The values for the effective yield stress were used in all subsequent simulations. The lower calculated fuel swelling in the rod-type element is due to an assumed biaxial stress state. Fuel swelling in plates results in plate thickness increase only. Likewise, in tubes, only the wall thickness increases. Irradiation experiments have shown that plate-type dispersion fuel elements can develop blisters or pillows at high U-235 burnup when fuel compounds exhibiting breakaway swelling are used at moderate to high fuel volume fractions. DART-calculated interaction layer thickness and fuel swelling follows the trends of the observations. 3 refs., 2 figs.

  17. An unusual swelling in the male perineum

    PubMed Central

    Parnham, Arie Stewart; Freeman, Alex; Kirkham, Alex; Muneer, Asif

    2015-01-01

    Median raphe cysts are a rare, congenital entity. We present a case and review the literature in respect to a 35-year-old man with a non-visible, painless midline swelling in the anterior perineum initially thought to be a liposarcoma. Subsequent histopathological examination confirmed a median raphe cyst. PMID:25612751

  18. The extrudate swell of HDPE: Rheological effects

    NASA Astrophysics Data System (ADS)

    Konaganti, Vinod Kumar; Ansari, Mahmoud; Mitsoulis, Evan; Hatzikiriakos, Savvas G.

    2017-05-01

    The extrudate swell of an industrial grade high molecular weight high-density polyethylene (HDPE) in capillary dies is studied experimentally and numerically using the integral K-BKZ constitutive model. The non-linear viscoelastic flow properties of the polymer resin are studied for a broad range of large step shear strains and high shear rates using the cone partitioned plate (CPP) geometry of the stress/strain controlled rotational rheometer. This allowed the determination of the rheological parameters accurately, in particular the damping function, which is proven to be the most important in simulating transient flows such as extrudate swell. A series of simulations performed using the integral K-BKZ Wagner model with different values of the Wagner exponent n, ranging from n=0.15 to 0.5, demonstrates that the extrudate swell predictions are extremely sensitive to the Wagner damping function exponent. Using the correct n-value resulted in extrudate swell predictions that are in excellent agreement with experimental measurements.

  19. PREVENTION OF PHOSPHATE - INDUCED MITOCHONDRIAL SWELLING

    PubMed Central

    Kroll, Arnold J.; Kuwabara, Toichiro

    1962-01-01

    The prevention of phosphate-induced mitochondrial swelling in the whole retina of the rabbit was studied with the electron microscope. It was found that a mixture of ATP, Mg++, and bovine serum albumin protected the mitochondria in vitro. This finding confirmed the results obtained spectrophotometrically with isolated rat liver mitochondria by Lehninger. PMID:13927020

  20. Bilateral Parotid Swelling in Polycystic Ovarian Syndrome.

    PubMed

    Yakubov, Yakov; Mandel, Louis

    2016-05-01

    Polycystic ovarian syndrome (PCOS) is recognized by the presence of polycystic ovaries, irregular menstruation, and increased androgen levels. Many patients have insulin resistance or impaired glucose tolerance and an associated development of type 2 diabetes mellitus. A patient with PCOS is presented whose cosmetic concerns centered on the prolonged existence of substantial bilateral parotid swelling. The pathophysiology, diagnosis, and therapy of sialosis are discussed.

  1. Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas.

    PubMed

    Di Paola, M; Paola, M D; Bozzali, M; Fadda, L; Musicco, M; Sabatini, U; Caltagirone, C

    2008-10-01

    At high altitudes barometric pressure is reduced and, thus, less oxygen is inhaled. Reduced oxygen concentration in brain tissue can lead to cerebral damage and neurological and cognitive deficits. The present study was designed to explore the effects of high-altitude exposure using a quantitative MRI technique, voxel-based morphometry. We studied nine world-class mountain climbers before (baseline) and after (follow-up) an extremely high-altitude ascent of Everest and K2. We investigated the effects of repeated extremely high-altitude exposures by comparing mountain climbers' scans at baseline with scans of 19 controls. In addition, we measured the effects of a single extremely high-altitude expedition by comparing mountain climbers' scans at baseline and follow-up. A region of reduced white matter density/volume was found in the left pyramidal tract near the primary (BA 4) and supplementary (BA 6) motor cortex when mountain climbers at baseline were compared with controls. Further, when mountain climbers' scans before and after the expedition were compared, a region of reduced grey matter density/volume was found in the left angular gyrus (BA 39). These findings suggest that extremely high-altitude exposures may cause subtle white and grey matter changes that mainly affect brain regions involved in motor activity.

  2. Hypoosmotic swelling modifies glutamate-glutamine cycle in the cerebral cortex and in astrocyte cultures

    PubMed Central

    Hyzinski-García, María C.; Vincent, Melanie Y.; Haskew-Layton, Renée E.; Dohare, Preeti; Keller, Richard W.; Mongin, Alexander A.

    2011-01-01

    In our previous work, we found that perfusion of the rat cerebral cortex with hypoosmotic medium triggers massive release of the excitatory amino acid L-glutamate but decreases extracellular levels of L-glutamine (R.E. Haskew-Layton et al., PLoS ONE, 3: e3543). The release of glutamate was linked to activation of volume-regulated anion channels (VRAC), while mechanism(s) responsible for alterations in extracellular glutamine remained unclear. When mannitol was added to the hypoosmotic medium in order to reverse reductions in osmolarity, changes in microdialysate levels of glutamine were prevented, indicating an involvement of cellular swelling. Since the main source of brain glutamine is astrocytic synthesis and export, we explored the impact of hypoosmotic medium on glutamine synthesis and transport in rat primary astrocyte cultures. In astrocytes, a 40% reduction in medium osmolarity moderately stimulated the release of L-[3H]glutamine by ~2-fold and produced no changes in L-[3H]glutamine uptake. In comparison, hypoosmotic medium stimulated the release of glutamate (traced with D[3H]aspartate) by more than 20-fold. In whole-cell enzymatic assays, we discovered that hypoosmotic medium caused a 20% inhibition of astrocytic conversion of L[3H]glutamate into L-[3H]glutamine by glutamine synthetase. Using an HPLC assay we further found a 35% reduction in intracellular levels of endogenous glutamine. Overall, our findings suggest that cellular swelling (1) inhibits astrocytic glutamine synthetase activity, and (2) reduces substrate availability for this enzyme due to the activation of VRAC. These combined effects likely lead to reductions in astrocytic glutamine export in vivo and may partially explain occurrence of hyperexcitability and seizures in human hyponatremia. PMID:21517854

  3. Swelling behavior of O-alkylated APCs coals as examined by the EPR spin probe method

    SciTech Connect

    Ding, R.; Tucker, D.; Kispert, L.W.

    1995-12-31

    Internal hydrogen bonding, especially in the bedding planes, plays an important role in determining the swelling characteristics in variously ranked coal. To further examine the swelling behavior using the EPR spin probe technique developed in this lab, known O-alkylation procedures have been used to derivatize the hydroxyl groups in APCS coal samples. Reduction of the extent of hydrogen bonding altered the amount of polar spin probe retention. Furthermore, an increase in coal swelling by nonpolar solvents such as toluene has been observed. By swelling O-alkylated APCS coals with nonplanar as well as polar solvents, using spin probes VII and VIII has yielded the spin probe retention as a function of rank when internal hydrogen bonding due to hydroxyl groups is removed in the APCS coals Beulah-Zap, Illinois No. 6, Upper Freeport and Pittsburgh No. 8.

  4. A fatal presentation of dermatomyositis with facial swelling.

    PubMed

    Dwivedi, Nishant; Michael, Christie; Lew, D Betty; Arnold, Sandra; Igarashi, Masanori; Bertorini, Tulio; Thompson, Jerome W; Myers, Linda K; Brown, Monica L

    2012-05-01

    Juvenile dermatomyositis (JDM) is the most common inflammatory autoimmune myopathy in children. Most common presentations consist of heliotrophic rash and/or gottron's papules in addition to proximal muscle weakness. A typical presentations have been reported. We present a 13-year-old African American male who presented with a two-week history of bilateral periorbital edema that was unresponsive to glucocorticoids. He had elevated transaminases but no detectable muscle weakness. A muscle biopsy was consistent with juvenile dermatomyositis. This case highlights the need to consider dermatomyositis in cases of facial swelling and the use of aggressive immunosuppressive therapies due to its associated vasculopathies.

  5. Effect of pulsed irradiation on void swelling in nickel

    SciTech Connect

    Brimhall, J.L.; Charlot, L.A.; Simonen, E.P.

    1981-07-01

    This study has compared the void microstructure in nickel induced by a pulsed ion bombardment to that induced by a steady-state irradiation. Pulse cycles of 10 seconds on and 10 seconds off produced no measurable difference in the void growth and swelling in the temperature range 775 to 975/sup 0/K compared to continuous irradiation at the same instantaneous dose rate. Void annealing during the pulse annealing period was minimal due to the large void sizes which were obtained in these irradiations. Hence no measurable effect of pulsing on void growth was observed.

  6. Osmotic swelling induces p75 neurotrophin receptor (p75NTR) expression via nitric oxide.

    PubMed

    Peterson, Suzanne; Bogenmann, Emil

    2003-09-05

    Brain injuries by physical trauma, epileptic seizures, or microbial infection upset the osmotic homeostasis resulting in cell swelling (cerebral edema), inflammation, and apoptosis. Expression of the neurotrophin receptor p75NTR is increased in the injured tissue and axon regeneration is repressed by the Nogo receptor using p75NTR as the signal transducer. Hence, p75NTR seems central to the injury response and we wished to determine the signals that regulate its expression. Here, we demonstrate that tonicity mediated cell swelling rapidly activates transcription of the endogenous p75NTR gene and of a p75NTR promoter-reporter gene in various cell types. Transcription activation is independent of de novo protein synthesis and requires the activities of phospholipase C, protein kinase C, and nitric-oxide synthase. Hence, p75NTR is a nitric oxide effector gene regulated by osmotic swelling, thereby providing a strategy for therapeutic intervention to modulate p75NTR functions following injury.

  7. Brain damage in dogs immediately following pulsatile and non-pulsatile blood flows in extracorporeal circulation

    PubMed Central

    Sanderson, J. M.; Wright, G.; Sims, F. W.

    1972-01-01

    The brains of dogs subjected to total cardiac bypass were examined for early signs of ischaemic nerve cell changes. Diffuse nerve cell changes were found immediately following two- and three-hour non-pulsatile perfusions but not following pulsatile perfusions of the same durations. The nerve cell changes found in the brains were acute cell swelling and early ischaemic cell change. Acute cell swelling was found only in the cerebellar Purkinje cells. Ischaemic cell change was found in several regions of the brain but the cerebral cortex and cerebellar Purkinje cells were most frequently affected. Diffuse nerve cell changes are attributed to non-pulsatile blood flow but some complicating factors are recognized. Focal lesions found in three brains may have been due to embolism by blood cell aggregates and/or gas microbubbles. Images PMID:5039442

  8. Effects of estradiol on ischemic factor-induced astrocyte swelling and AQP4 protein abundance.

    PubMed

    Rutkowsky, Jennifer M; Wallace, Breanna K; Wise, Phyllis M; O'Donnell, Martha E

    2011-07-01

    In the early hours of ischemic stroke, cerebral edema forms as Na, Cl, and water are secreted across the blood-brain barrier (BBB) and astrocytes swell. We have shown previously that ischemic factors, including hypoxia, aglycemia, and arginine vasopressin (AVP), stimulate BBB Na-K-Cl cotransporter (NKCC) and Na/H exchanger (NHE) activities and that inhibiting NKCC and/or NHE by intravenous bumetanide and/or HOE-642 reduces edema and infarct in a rat model of ischemic stroke. Estradiol also reduces edema and infarct in this model and abolishes ischemic factor stimulation of BBB NKCC and NHE. There is evidence that NKCC and NHE also participate in ischemia-induced swelling of astrocytes. However, little is known about estradiol effects on astrocyte cell volume. In this study, we evaluated the effects of AVP (100 nM), hypoxia (7.5% O(2)), aglycemia, hypoxia (2%)/aglycemia [oxygen glucose deprivation (OGD)], and estradiol (1-100 nM) on astrocyte cell volume using 3-O-methyl-d-[(3)H]glucose equilibration methods. We found that AVP, hypoxia, aglycemia, and OGD (30 min to 5 h) each significantly increased astrocyte cell volume, and that estradiol (30-180 min) abolished swelling induced by AVP or hypoxia, but not by aglycemia or OGD. Bumetanide and/or HOE-642 also abolished swelling induced by AVP but not aglycemia. Abundance of aquaporin-4, known to participate in ischemia-induced astrocyte swelling, was significantly reduced following 7-day but not 2- or 3-h estradiol exposures. Our findings suggest that hypoxia, aglycemia, and AVP each contribute to ischemia-induced astrocyte swelling, and that the edema-attenuating effects of estradiol include reduction of hypoxia- and AVP-induced astrocyte swelling and also reduction of aquaporin-4 abundance.

  9. Megalencephalic leukoencephalopathy with subcortical cysts: chronic white matter oedema due to a defect in brain ion and water homoeostasis.

    PubMed

    van der Knaap, Marjo S; Boor, Ilja; Estévez, Raúl

    2012-11-01

    Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterised by chronic white matter oedema. The disease has an infantile onset and leads to slow neurological deterioration in most cases, but, surprisingly, some patients recover. The first disease gene, MLC1, identified in 2001, is mutated in 75% of patients. At that time, nothing was known about MLC1 protein function and the pathophysiology of MLC. More recently, HEPACAM (also called GLIALCAM) has been identified as a second disease gene. GlialCAM serves as an escort for MLC1 and the chloride channel CLC2. The defect in MLC1 has been shown to hamper the cell volume regulation of astrocytes. One of the most important consequences involves the potassium siphoning process, which is essential in brain ion and water homoeostasis. An understanding of the mechanisms of white matter oedema in MLC is emerging. Further insight into the specific function of MLC1 is necessary to find treatment targets. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Structural and functional improvements due to robot-assisted gait training in the stroke-injured brain.

    PubMed

    Yang, Hea Eun; Kyeong, Sunghyon; Lee, Seung Hwa; Lee, Won-Jae; Ha, Sang Won; Kim, Seung Min; Kang, Hyunkoo; Lee, Won Min; Kang, Chang Soon; Kim, Dae Hyun

    2017-01-10

    Robot-assisted gait training (RAGT) can improve walking ability after stroke. Because the underlying mechanisms are still unknown, we analyzed changes in post-stroke injured brains after RAGT. Ten non-ambulatory patients receiving inpatient rehabilitation were examined within 3 months of stroke onset. RAGT consisted of 45min of training, 3days per week. We acquired diffusion tensor imaging (DTI) data before and after 20 sessions of RAGT. Fractional anisotropy (FA) maps were then used to determine neural changes after RAGT. Fugl-Meyer motor assessment of the lower extremity, motricity index of the lower extremity, functional ambulation category, and trunk control tests were also conducted before training, after 10 and 20 RAGT sessions, and at the 1-month follow-up. After RAGT, the supplementary motor area of the unaffected hemisphere showed increased FA, but the internal capsule, substantia nigra, and pedunculopontine nucleus of the affected hemisphere showed decreased FA. All clinical outcome measures improved after 20 sessions of RAGT. Our findings indicate that RAGT can facilitate plasticity in the intact supplementary motor area, but not the injured motor-related areas, in the affected hemisphere.

  11. Postmortem angiography in computed tomography and magnetic resonance imaging in a case of fatal hemorrhage due to an arterio-venous malformation in the brain.

    PubMed

    Franckenberg, Sabine; Schulze, Claudia; Bolliger, Stephan A; Gascho, Dominic; Thali, Michael J; Flach, Patricia M

    2015-05-01

    Autopsy is the traditional gold standard for determining the cause and manner of death in a forensic death investigation. However, postmortem imaging plays an ever-growing role in preliminary examination, even replacing conventional autopsy in some cases. This case report presents a case of massive intra-axial brain hemorrhage due to an arterio-venous malformation. The cause and manner of death were exclusively determined by postmortem radiology. Based on radiological findings, the autopsy was considered redundant and cancelled by the public prosecutor.

  12. [Submandibular swelling and its differential diagnosis].

    PubMed

    Eleftheriadis, I; Papadimitriou, P; Tzelepi, H

    1990-06-01

    The lump in the submandibular area is not too unusual. Nonmalignant swelling may be caused by mumps, sialadenitis, Sjögren syndrome, cysts and infections. Submandibular lymphadenopathy may also result from infections of teeth, upper respiratory track, sinuses and tonsils or infections mononucleosis and cut scratch disease. The neoplastic growths in the submandibular area may include in most of the case tumors of the submandibular gland, the tail of the parotid gland, the Hodgkin's disease and non-Hodgkin's lymphomas. However, since the greatest cause of asymmetric submandibular enlargement, especially in people elder than 40 years old is the metastatic disease, the physician should always first seek to eliminate a primary site in the head, face and mouth area. Possible origin from other parts of the body should also be ruled out. In this article we are presenting representative cases of submandibular swelling.

  13. Morphological effect on swelling behaviour of hydrogel

    SciTech Connect

    Yacob, Norzita; Hashim, Kamaruddin

    2014-02-12

    Hydrogels are hydrophilic polymer networks that are capable of imbibing large amounts of water. In this work, hydrogels prepared from natural and synthetic polymers were irradiated by using electron beam irradiation. The morphology of hydrogel inter-polymeric network (IPN) was investigated using Scanning Electron Microscopy (SEM). The studies reveal correlations between pore sizes of IPN with degree of cross-linking. This relation also has an effect on swelling properties of the hydrogel. The results indicated that hydrogel with smaller pore size, as a result of much dense IPN, would decrease water uptake capacity. Combination of natural and synthetic polymers to form hydrogel affects the pore size and swelling property of the hydrogel as compared to each component of polymer.

  14. Optically Teasing Apart Neural Swelling and Depolarization

    PubMed Central

    Foust, Amanda J.; Rector, David M.

    2007-01-01

    We measured birefringence, 90 degree scattered light, and voltage sensitive dye changes from lobster walking leg nerves. Systematic application of key chemical agents revealed separate cellular mechanisms underlying fast optical signals. Each agent exhibited mixed effects, some having a greater effect on cellular swelling and refractive index, and some altering membrane potential. Birefringence changes were tightly correlated with voltage sensitive dye signals and were perturbed by those agents that altered membrane potential. Signals from light scattered at 90 degrees corroborated the hypothesis that large angle scattering signals arise from changes in the interstitial spaces and were perturbed by those agents that altered cellular swelling and refractive index. We conclude that multiple cellular mechanisms can be exploited to measure rapid optical signals. Since birefringence produces much larger changes than scattering, the use of polarized light might lead to improvements in imaging neural activity with high temporal resolution, especially since birefringence changes corresponded closely to membrane potential. PMID:17303339

  15. Capillary rise and swelling in cellulose sponges

    NASA Astrophysics Data System (ADS)

    Ha, Jonghyun; Kim, Jungchul; Kim, Ho-Young

    2015-11-01

    A cellulose sponge, which is a mundane example of a porous hydrophilic structure, can absorb and hold a significant amount of liquid. We present the results of experimental and theoretical investigation of the dynamics of the capillary imbibition of various aqueous solutions in the sponge that swells at the same time. We find that the rate of water rise against the resistance caused by gravitational and viscous effects deviates from Washburn's rule beyond a certain threshold height. We rationalize the novel power law of the rise height versus time by combining Darcy's law with hygroscopic swelling equation and also predict the threshold height. The scaling law constructed through this work agrees well with the experimental results, shedding light on the physics of capillary flow in deforming porous media.

  16. Genital swellings in silvered langurs: what do they indicate?

    PubMed

    Shelmidine, Nichole; Borries, Carola; Koenig, Andreas

    2007-05-01

    The occurrence of genital swellings was examined in adult female silvered langurs (Trachypithecus cristatus). In contrast to the exaggerated swellings found in cercopithecines and apes, genital swellings in silvered langurs are confined to the vulva and the surrounding perineum, but they may nevertheless convey information similar to that of exaggerated swellings (i.e., correlate with the receptive period and fertility). If so, genital swellings would be expected to occur most frequently in cycling females, and sexual behavior and male interest should most frequently involve females with swellings. Swellings during gestation, if they occur at all, should be most pronounced at the beginning. Swelling sizes (in three size categories) in nine adult females were examined throughout different reproductive states (cycling, pregnant, and lactating), and in relation to proceptivity, receptivity, and attractivity. Data were collected from November 2002 through March 2004 (on 500 of the 502 calendar days) at the Wildlife Conservation Society's Bronx Zoo. Female sexual behavior (proceptivity and receptivity) and male inspection (attractivity) were recorded each day for 6 hr by video camera (2,948 hr total) and analyzed as present or absent for each female day. Swellings were assessed directly (not from videotapes). In contrast to the predictions, swellings occurred significantly less frequently in cycling females (compared to pregnant females) and no regular, cyclic pattern could be detected. Some females conceived without a swelling. Female attractivity was independent of swellings but coincided with proceptive behavior. Swellings occurred most frequently in pregnant females, especially toward the end of the gestation period. Therefore, genital swellings in silvered langurs are not similar to exaggerated swellings or the smaller genital swellings that have been described for some other primates. It is currently not clear what they signal to conspecifics. Male behavior needs

  17. Anions Govern Cell Volume: A Case Study of Relative Astrocytic and Neuronal Swelling in Spreading Depolarization

    PubMed Central

    2016-01-01

    Cell volume changes are ubiquitous in normal and pathological activity of the brain. Nevertheless, we know little about the dynamics of cell and tissue swelling, and the differential changes in the volumes of neurons and glia during pathological states such as spreading depolarizations (SD) under ischemic and non–ischemic conditions, and epileptic seizures. By combining the Hodgkin–Huxley type spiking dynamics, dynamic ion concentrations, and simultaneous neuronal and astroglial volume changes into a comprehensive model, we elucidate why glial cells swell more than neurons in SD and the special case of anoxic depolarization (AD), and explore the relative contributions of the two cell types to tissue swelling. Our results demonstrate that anion channels, particularly Cl−, are intrinsically connected to cell swelling and blocking these currents prevents changes in cell volume. The model is based on a simple and physiologically realistic description. We introduce model extensions that are either derived purely from first physical principles of electroneutrality, osmosis, and conservation of particles, or by a phenomenological combination of these principles and known physiological facts. This work provides insights into numerous studies related to neuronal and glial volume changes in SD that otherwise seem contradictory, and is broadly applicable to swelling in other cell types and conditions. PMID:26974767

  18. Membrane reserves and hypotonic cell swelling.

    PubMed

    Groulx, Nicolas; Boudreault, Francis; Orlov, Sergei N; Grygorczyk, Ryszard

    2006-01-01

    To accommodate expanding volume (V) during hyposmotic swelling, animal cells change their shape and increase surface area (SA) by drawing extra membrane from surface and intracellular reserves. The relative contributions of these processes, sources and extent of membrane reserves are not well defined. In this study, the SA and V of single substrate-attached A549, 16HBE14o(-), CHO and NIH 3T3 cells were evaluated by reconstructing cell three-dimensional topology based on conventional light microscopic images acquired simultaneously from two perpendicular directions. The size of SA reserves was determined by swelling cells in extreme 98% hypotonic (approximately 6 mOsm) solution until membrane rupture; all cell types examined demonstrated surprisingly large membrane reserves and could increase their SA 3.6 +/- 0.2-fold and V 10.7 +/- 1.5-fold. Blocking exocytosis (by N-ethylmaleimide or 10 degrees C) reduced SA and V increases of A549 cells to 1.7 +/- 0.3-fold and 4.4 +/- 0.9-fold, respectively. Interestingly, blocking exocytosis did not affect SA and V changes during moderate swelling in 50% hypotonicity. Thus, mammalian cells accommodate moderate (<2-fold) V increases mainly by shape changes and by drawing membrane from preexisting surface reserves, while significant endomembrane insertion is observed only during extreme swelling. Large membrane reserves may provide a simple mechanism to maintain membrane tension below the lytic level during various cellular processes or acute mechanical perturbations and may explain the difficulty in activating mechanogated channels in mammalian cells.

  19. High concentrations of NaCl induce cell swelling leading to senescence in human cells.

    PubMed

    Yamakami, Yoshimi; Yonekura, Ryuzo; Matsumoto, Yuko; Takauji, Yuki; Miki, Kensuke; Fujii, Michihiko; Ayusawa, Dai

    2016-01-01

    Cell swelling and retardation in DNA replication are always observed in senescent cells. When DNA replication is slowed down with RNA and protein syntheses unchanged in proliferating cells, it causes a phenomenon known as unbalanced growth. The purpose of this study is to assess the role of cell swelling in unbalanced growth in terms of senescence and investigate the mechanism underlying this phenomenon. We tried to induce cell swelling with minimum damage to cells in this study. We perturbed the osmoregulatory functions to induce cell swelling under hypotonic and hypertonic conditions in normal human fibroblasts. Addition of excess NaCl was found to induce significant cell and nuclear swelling in dose- and time-dependent manners. Excess NaCl immediately retarded DNA replication, accumulated cells at G1 phase of the cell cycle, and eventually deprived division potential of the cells. Such cells showed typical senescent cell shape followed by expression of the typical senescence-associated genes. Excess NaCl also activated ERK1/2, p38, and JNK of the mitogen activated protein kinase family. Addition of U0126, an inhibitor of ERK1/2, prevented appearance of senescent features induced by excess NaCl. These results suggest that hypertonic conditions induce cell swelling due to unbalanced growth, thereby leading to cellular senescence.

  20. Evaluation of ettringite-related swelling mechanisms for treated chromite ore processing residue.

    PubMed

    Moon, Deok Hyun; Wazne, Mahmoud; Dermatas, Dimitris; Sanchez, Adriana M; Cheong, Kyung Hoon; Park, Jeong-Hun

    2015-01-01

    Accelerated one-dimensional unconfined swell tests were conducted for ferrous sulfate chromite ore processing residue (COPR) field-treated samples. The field-treated samples were subjected to wet and dry cycles over 100 days to accelerate the lithification of the samples. Parallel laboratory experiments were performed to investigate the effects of mineralogy on COPR swell under controlled conditions. The field and laboratory samples were treated with ferrous sulfate at a ferrous-to-Cr(6+) molar stoichiometric ratios of eight (8×) and five (5×). X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) analyses were used to investigate the mineralogical changes upon treatment. The swell results indicated that significant COPR swelling was observed in all of the tested samples. The swelling was more pronounced in the 5× treated COPR sample than in the 8× treated COPR sample. Moreover, the laboratory-treated samples showed greater swelling behavior as compared with the field-treated samples, which was most probably due to the high dry density of the COPR, indicating that dry density was a more dominant factor than lithification. XRPD and SEM-EDX results confirmed that significant ettringite formation occurred in all treated samples.

  1. A structural model for the in vivo human cornea including collagen-swelling interaction

    PubMed Central

    Cheng, Xi; Petsche, Steven J.; Pinsky, Peter M.

    2015-01-01

    A structural model of the in vivo cornea, which accounts for tissue swelling behaviour, for the three-dimensional organization of stromal fibres and for collagen-swelling interaction, is proposed. Modelled as a binary electrolyte gel in thermodynamic equilibrium, the stromal electrostatic free energy is based on the mean-field approximation. To account for active endothelial ionic transport in the in vivo cornea, which modulates osmotic pressure and hydration, stromal mobile ions are shown to satisfy a modified Boltzmann distribution. The elasticity of the stromal collagen network is modelled based on three-dimensional collagen orientation probability distributions for every point in the stroma obtained by synthesizing X-ray diffraction data for azimuthal angle distributions and second harmonic-generated image processing for inclination angle distributions. The model is implemented in a finite-element framework and employed to predict free and confined swelling of stroma in an ionic bath. For the in vivo cornea, the model is used to predict corneal swelling due to increasing intraocular pressure (IOP) and is adapted to model swelling in Fuchs' corneal dystrophy. The biomechanical response of the in vivo cornea to a typical LASIK surgery for myopia is analysed, including tissue fluid pressure and swelling responses. The model provides a new interpretation of the corneal active hydration control (pump-leak) mechanism based on osmotic pressure modulation. The results also illustrate the structural necessity of fibre inclination in stabilizing the corneal refractive surface with respect to changes in tissue hydration and IOP. PMID:26156299

  2. Dynamic swelling behavior of interpenetrating polymer networks in response to temperature and pH

    PubMed Central

    Slaughter, Brandon V.; Blanchard, Aaron T.; Maass, Katie F.; Peppas, Nicholas A.

    2015-01-01

    Temperature responsive hydrogels based on ionic polymers exhibit swelling transitions in aqueous solutions as a function of shifting pH and ionic strength, in addition to temperature. Applying these hydrogels to useful applications, particularly for biomedical purposes such as drug delivery and regenerative medicine, is critically dependent on understanding the hydrogel solution responses as a function of all three parameters together. In this work, interpenetrating polymer network (IPN) hydrogels of polyacrylamide and poly(acrylic acid) were formulated over a broad range of synthesis variables using a fractional factorial design, and were examined for equilibrium temperature responsive swelling in a variety of solution conditions. Due to the acidic nature of these IPN hydrogels, usable upper critical solution temperature (UCST) responses for this system occur in mildly acidic environments. Responses were characterized in terms of maximum equilibrium swelling and temperature-triggered swelling using turbidity and gravimetric measurements. Additionally, synthesis parameters critical to achieving optimal overall swelling, temperature-triggered swelling, and sigmoidal temperature transitions for this IPN system were analyzed based on the fractional factorial design used to formulate these hydrogels. PMID:26405349

  3. Evolution of midplate hotspot swells: Numerical solutions

    NASA Technical Reports Server (NTRS)

    Liu, Mian; Chase, Clement G.

    1990-01-01

    The evolution of midplate hotspot swells on an oceanic plate moving over a hot, upwelling mantle plume is numerically simulated. The plume supplies a Gaussian-shaped thermal perturbation and thermally-induced dynamic support. The lithosphere is treated as a thermal boundary layer with a strongly temperature-dependent viscosity. The two fundamental mechanisms of transferring heat, conduction and convection, during the interaction of the lithosphere with the mantle plume are considered. The transient heat transfer equations, with boundary conditions varying in both time and space, are solved in cylindrical coordinates using the finite difference ADI (alternating direction implicit) method on a 100 x 100 grid. The topography, geoid anomaly, and heat flow anomaly of the Hawaiian swell and the Bermuda rise are used to constrain the models. Results confirm the conclusion of previous works that the Hawaiian swell can not be explained by conductive heating alone, even if extremely high thermal perturbation is allowed. On the other hand, the model of convective thinning predicts successfully the topography, geoid anomaly, and the heat flow anomaly around the Hawaiian islands, as well as the changes in the topography and anomalous heat flow along the Hawaiian volcanic chain.

  4. [Extensive swelling reaction after a pentavalent vaccination].

    PubMed

    Gébus, M; Barbier, C; Bost-Bru, C; Michard-Lenoir, A P; Plantaz, D

    2015-09-01

    Injection site reactions (ISRs) are quite common side effects defined by a local adverse drug reaction directly caused by a vaccine. Twenty-four hours after an intramuscular injection (in the deltoid muscle) of the diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis, Haemophilus influenza type b (DTPCa-Hib) combined vaccine, a 3-year-old boy developed fever. A few hours later, local redness and swelling appeared at the injection site, with rapid extension to the entire limb, it was pain-free, and no other clinical anomalies were present. The patient received intravenous antibiotics for suspected cellulitis. The progression was favorable in 12h (apyrexia and decreased limb swelling), allowing the intravenous antibiotic treatment to be discontinued. Since the child was in excellent general health and recovery was fast, an ISR was diagnosed. Extensive limb swelling is frequent, mostly after the fourth dose of DTPCa-Hib. Deltoid muscle injection of DTP vaccine increases the risk of ISR compared to injection in the thigh, before the age of 3 years. The introduction of acellular pertussis vaccine decreased the risk of general side effects but may increase the risk of ISR. These reactions disappear with symptomatic treatment and do not contraindicate the product.

  5. Swelling and dissolution of cellulose in amine oxide/water systems

    SciTech Connect

    Chanzy, H.; Noe, P.; Paillet, M.; Smith, P.

    1983-01-01

    The swelling behavior and the dissolution process of various cellulosic fibers, both native and regenerated, in N-methylmorpholine N-oxide (MMNO), dimethylethanolamine N-oxide (DMEAO), and mixtures thereof were studied in the presence of various amounts of water. The principal tools in this investigation were optical microscopy and wide-angle X-ray scattering (WAXS). The two amine oxides could either dissolve or only swell cellulose, depending on the water concentration, which was found to be of critical importance. Three domains of water concentration were found important. When only a few percent water was present, cellulose fibers, such as ramie, cotton, rayon, etc., dissolved readily without noticeable swelling in the amine oxide/water system brought above its melting point. At a relatively high water concentration (e.g., 18% w/w for MMNO), the cellulose fibers exhibited an extensive swelling (up to sevenfold increase in the fiber diameter) but no dissolution. In that case, the removal of the swelling agent showed that the initial native cellulose fibers were converted into an unoriented cellulose II structure. With still greater water content (e.g., 20% and more for MMNO or 15% for DMEAO), only partial swelling was observed, and the native cellulose fibers recovered their initial oriented cellulose I structure after removal of the swelling medium. X-ray investigations provided no evidence forthe formation of cellulose/solvent complexes in the swollen fibers. A relatively large decrease of the cellulose I (110) reflection was found in the WAXS patterns of the gels. This is interpreted as due to a preferential cleavage of the cellulose crystals along the corresponding plane when the cellulose fibers are exposed to the swelling forces of the amine oxide/water systems. 29 references, 13 figures, 1 table.

  6. Brain-computer interface with somatosensory feedback improves functional recovery from severe hemiplegia due to chronic stroke

    PubMed Central

    Ono, Takashi; Shindo, Keiichiro; Kawashima, Kimiko; Ota, Naoki; Ito, Mari; Ota, Tetsuo; Mukaino, Masahiko; Fujiwara, Toshiyuki; Kimura, Akio; Liu, Meigen; Ushiba, Junichi

    2014-01-01

    Recent studies have shown that scalp electroencephalogram (EEG) based brain-computer interface (BCI) has a great potential for motor rehabilitation in stroke patients with severe hemiplegia. However, key elements in BCI architecture for functional recovery has yet to be clear. We in this study focused on the type of feedback to the patients, which is given contingently to their motor-related EEG in a BCI context. The efficacy of visual and somatosensory feedbacks was compared by a two-group study with the chronic stroke patients who are suffering with severe motor hemiplegia. Twelve patients were asked an attempt of finger opening in the affected side repeatedly, and the event-related desynchronization (ERD) in EEG of alpha and beta rhythms was monitored over bilateral parietal regions. Six patients were received a simple visual feedback in which the hand open/grasp picture on screen was animated at eye level, following significant ERD. Six patients were received a somatosensory feedback in which the motor-driven orthosis was triggered to extend the paralyzed fingers from 90 to 50°. All the participants received 1-h BCI treatment with 12–20 training days. After the training period, while no changes in clinical scores and electromyographic (EMG) activity were observed in visual feedback group after training, voluntary EMG activity was newly observed in the affected finger extensors in four cases and the clinical score of upper limb function in the affected side was also improved in three participants in somatosensory feedback group. Although the present study was conducted with a limited number of patients, these results imply that BCI training with somatosensory feedback could be more effective for rehabilitation than with visual feedback. This pilot trial positively encouraged further clinical BCI research using a controlled design. PMID:25071543

  7. IVIG treatment of mild cognitive impairment due to Alzheimer's disease: a randomised double-blinded exploratory study of the effect on brain atrophy, cognition and conversion to dementia.

    PubMed

    Kile, Shawn; Au, William; Parise, Carol; Rose, Kimberley; Donnel, Tammy; Hankins, Andrea; Chan, Matthew; Ghassemi, Azad

    2017-02-01

    To determine the effect of intravenous immunoglobulin (IVIG) on brain atrophy and cognitive function in mild cognitive impairment (MCI) due to Alzheimer's disease (AD). 50 participant 50-84 years of age with amnestic MCI were administered 0.4 g/kg 10% IVIG or 0.9% saline every 2 weeks for a total of 5 infusions (2 g/kg total dose) in a randomised double-blinded design. MRI brain was completed at baseline, 12  and 24 months. Cognitive testing was completed at baseline and every 4 months. Participants were stratified into early and late (LMCI) MCI stages. Average annualised per cent change in ventricular volume was computed as a measure of brain atrophy. There was significantly less brain atrophy (p=0.037, adjusted for MCI status) in the IVIG group (5.87%) when compared with placebo (8.14%) at 12 months; at 24 months, the reduction in brain atrophy no longer reached statistical significance. The LMCI participants who received IVIG performed better on Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog; p=0.011) and Mini-Mental State Examination (MMSE; p=0.004) at 1 year; these differences were not present after 2 years. There was no difference in conversion to AD dementia between the treatment and control groups after 2 years; however, at 1 year, there were fewer conversions from LMCI to AD dementia in the IVIG group (33.3%) when compared with control group (58.3%). This exploratory study provides limited evidence that a short course of IVIG administered in the MCI stage of AD reduces brain atrophy, prevents cognitive decline in LMCI and delays conversion to AD dementia for at least 1 year; however, this effect of IVIG appears to wane by 2 years. ClinicalTrials.gov, NCT01300728. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Increased susceptibility of transgenic mice expressing human PrP to experimental sheep bovine spongiform encephalopathy is not due to increased agent titre in sheep brain tissue

    PubMed Central

    Plinston, Chris; Hart, Patricia; Hunter, Nora; Manson, Jean C.

    2014-01-01

    Bovine spongiform encephalopathy (BSE) in cattle and variant Creutzfeldt–Jakob disease in humans have previously been shown to be caused by the same strain of transmissible spongiform encephalopathy agent. It is hypothesized that the agent spread to humans following consumption of food products prepared from infected cattle. Despite evidence supporting zoonotic transmission, mouse models expressing human prion protein (HuTg) have consistently shown poor transmission rates when inoculated with cattle BSE. Higher rates of transmission have however been observed when these mice are exposed to BSE that has been experimentally transmitted through sheep or goats, indicating that humans may potentially be more susceptible to BSE from small ruminants. Here we demonstrate that increased transmissibility of small ruminant BSE to HuTg mice was not due to replication of higher levels of infectivity in sheep brain tissue, and is instead due to other specific changes in the infectious agent. PMID:24828334

  9. Increased susceptibility of transgenic mice expressing human PrP to experimental sheep bovine spongiform encephalopathy is not due to increased agent titre in sheep brain tissue.

    PubMed

    Plinston, Chris; Hart, Patricia; Hunter, Nora; Manson, Jean C; Barron, Rona M

    2014-08-01

    Bovine spongiform encephalopathy (BSE) in cattle and variant Creutzfeldt-Jakob disease in humans have previously been shown to be caused by the same strain of transmissible spongiform encephalopathy agent. It is hypothesized that the agent spread to humans following consumption of food products prepared from infected cattle. Despite evidence supporting zoonotic transmission, mouse models expressing human prion protein (HuTg) have consistently shown poor transmission rates when inoculated with cattle BSE. Higher rates of transmission have however been observed when these mice are exposed to BSE that has been experimentally transmitted through sheep or goats, indicating that humans may potentially be more susceptible to BSE from small ruminants. Here we demonstrate that increased transmissibility of small ruminant BSE to HuTg mice was not due to replication of higher levels of infectivity in sheep brain tissue, and is instead due to other specific changes in the infectious agent. © 2014 The Authors.

  10. Synergistic action of hypoosmolarity and glutamine in inducing acute swelling of retinal glial (Müller) cells.

    PubMed

    Karl, Anett; Wurm, Antje; Pannicke, Thomas; Krügel, Katja; Obara-Michlewska, Marta; Wiedemann, Peter; Reichenbach, Andreas; Albrecht, Jan; Bringmann, Andreas

    2011-02-01

    High blood ammonia, elevated glutamine, and hyponatremia are pathogenic factors contributing to astrocytic swelling and brain edema in liver failure. We investigated the effects of hypoosmolarity, ammonia, and glutamine on the induction of glial cell swelling in freshly isolated slices of the rat retina. Glutamine, but not ammonia or hypoosmolarity per se, evoked a rapid (within one minute) swelling of retinal glial (Müller) cell bodies under hypoosmotic conditions. Under isoosmotic conditions, glutamine evoked a delayed swelling after 10 min of exposure. The effect of glutamine was concentration-dependent, with half-maximal and maximal effects at ∼ 0.1 and 0.5 mM. Glutamine in hypoosmotic solution induced a dissipation of the mitochondrial membrane potential. The effects on the mitochondrial membrane potential and the glial soma size were reduced by (i) agents which inhibit the transfer of glutamine into mitochondria and its hydrolysis there, (ii) inhibition of the mitochondrial permeability transition, (iii) inhibitors of oxidative-nitrosative stress, and (iv) inhibitors of phospholipase A(2) and cyclooxygenase. Glutamine-induced glial swelling was also prevented by ATP and adenosine, acting at adenosine A(1) receptors. The data suggest that hypoosmolarity accelerates the swelling-inducing effect of glutamine on retinal glial cells, and that swelling induction by glutamine is mediated by inducing oxidative-nitrosative stress, inflammatory lipid mediators, and mitochondrial dysfunction.

  11. Feet swelling in a multistage ultraendurance triathlete: a case study

    PubMed Central

    Knechtle, Beat; Zingg, Matthias Alexander; Knechtle, Patrizia; Rosemann, Thomas; Rüst, Christoph Alexander

    2015-01-01

    Recent studies investigating ultraendurance athletes showed an association between excessive fluid intake and swelling of the lower limbs such as the feet. To date, this association has been investigated in single-stage ultraendurance races, but not in multistage ultraendurance races. In this case study, we investigated a potential association between fluid intake and feet swelling in a multistage ultraendurance race such as a Deca Iron ultratriathlon with ten Ironman triathlons within 10 consecutive days. A 49-year-old well-experienced ultratriathlete competed in autumn 2013 in the Deca Iron ultratriathlon held in Lonata del Garda, Italy, and finished the race as winner within 129:33 hours:minutes. Changes in body mass (including body fat and lean body mass), foot volume, total body water, and laboratory measurements were assessed. Food and fluid intake during rest and competing were recorded, and energy and fluid turnovers were estimated. During the ten stages, the volume of the feet increased, percentage body fat decreased, creatinine and urea levels increased, hematocrit and hemoglobin values decreased, and plasma [Na+] remained unchanged. The increase in foot volume was significantly and positively related to fluid intake during the stages. The poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. This case report shows that the volume of the foot increased during the ten stages, and the increase in volume was significantly and positively related to fluid intake during the stages. Furthermore, the poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. The continuous feet swelling during the race was most probably due to a combination of a high fluid intake and a progressive decline in renal function (ie, continuous increase in creatinine and urea), leading to body fluid retention (ie, increase in total body water). PMID:26508884

  12. Modeling multidomain hydraulic properties of shrink-swell soils

    NASA Astrophysics Data System (ADS)

    Stewart, Ryan D.; Abou Najm, Majdi R.; Rupp, David E.; Selker, John S.

    2016-10-01

    Shrink-swell soils crack and become compacted as they dry, changing properties such as bulk density and hydraulic conductivity. Multidomain models divide soil into independent realms that allow soil cracks to be incorporated into classical flow and transport models. Incongruously, most applications of multidomain models assume that the porosity distributions, bulk density, and effective saturated hydraulic conductivity of the soil are constant. This study builds on a recently derived soil shrinkage model to develop a new multidomain, dual-permeability model that can accurately predict variations in soil hydraulic properties due to dynamic changes in crack size and connectivity. The model only requires estimates of soil gravimetric water content and a minimal set of parameters, all of which can be determined using laboratory and/or field measurements. We apply the model to eight clayey soils, and demonstrate its ability to quantify variations in volumetric water content (as can be determined during measurement of a soil water characteristic curve) and transient saturated hydraulic conductivity, Ks (as can be measured using infiltration tests). The proposed model is able to capture observed variations in Ks of one to more than two orders of magnitude. In contrast, other dual-permeability models assume that Ks is constant, resulting in the potential for large error when predicting water movement through shrink-swell soils. Overall, the multidomain model presented here successfully quantifies fluctuations in the hydraulic properties of shrink-swell soil matrices, and are suitable for use in physical flow and transport models based on Darcy's Law, the Richards Equation, and the advection-dispersion equation.

  13. Role of Defects in Swelling and Creep of Irradiated SiC

    SciTech Connect

    Szlufarska, Izabela; Voyles, Paul; Sridharan, Kumar; Katoh, Yutai

    2016-01-16

    Silicon carbide is a promising cladding material because of its high strength and relatively good corrosion resistance. However, SiC is brittle and therefore SiC-based components need to be carefully designed to avoid cracking and failure by fracture. In design of SiC-based composites for nuclear reactor applications it is essential to take into account how mechanical properties are affected by radiation and temperature, or in other words, what strains and stresses develop in this material due to environmental conditions. While thermal strains in SiC can be predicted using classical theories, radiation-induced strains are much less understood. In particular, it is critical to correctly account for radiation swelling and radiation creep, which contribute significantly to dimensional instability of SiC under radiation. Swelling typically increases logarithmically with radiation dose and saturates at relatively low doses (damage levels of a few dpa). Consequently, swelling-induced stresses are likely to develop within a few months of operation of a reactor. Radiation-induced volume swelling in SiC can be as high as 2%, which is significantly higher than the cracking strain of 0.1% in SiC. Swelling-induced strains will lead to enormous stresses and fracture, unless these stresses can be relaxed via some other mechanism. An effective way to achieve stress relaxation is via radiation creep. Although it has been hypothesized that both radiation swelling and radiation creep are driven by formation of defect clusters, existing models for swelling and creep in SiC are limited by the lack of understanding of specific defects that form due to radiation in the range of temperatures relevant to fuel cladding in light water reactors (LWRs) (<1000°C). For example, defects that can be detected with traditional transmission electron microscopy (TEM) techniques account only for 10-45% of the swelling measured in irradiated SiC. Here, we have undertaken an integrated experimental and

  14. Acute fatal parainfectious cerebellar swelling in two children. A rare or an overlooked situation?

    PubMed

    Roulet Perez, E; Maeder, P; Cotting, J; Eskenazy-Cottier, A C; Deonna, T

    1993-12-01

    We report 2 previously healthy children who developed sudden unexpected respiratory arrest and brain death, during a presumed Epstein-Barr meningitis in one case and a multisystemic infection of unknown etiology in the other. Diffuse swelling of the cerebellum with upward transtentorial and downward tonsillar herniation, shown by brain CT-scan and MRI obtained after the acute event, was the most probable cause of death. Review of CT images performed before or at the onset of deterioration already showed discrete signs of early upward herniation of the cerebellar vermis that were initially overlooked. At autopsy in the first case, an acute lymphomonocytic meningoencephalitis with predominant involvement of the cerebellum was observed. Few similar cases were found in the literature, indicating that acute cerebellar swelling is either a very rare or an unrecognized, possibly preventable cause of death in acute inflammatory or non-inflammatory encephalopathies in children.

  15. Segmentation of knee injury swelling on infrared images

    NASA Astrophysics Data System (ADS)

    Puentes, John; Langet, Hélène; Herry, Christophe; Frize, Monique

    2011-03-01

    Interpretation of medical infrared images is complex due to thermal noise, absence of texture, and small temperature differences in pathological zones. Acute inflammatory response is a characteristic symptom of some knee injuries like anterior cruciate ligament sprains, muscle or tendons strains, and meniscus tear. Whereas artificial coloring of the original grey level images may allow to visually assess the extent inflammation in the area, their automated segmentation remains a challenging problem. This paper presents a hybrid segmentation algorithm to evaluate the extent of inflammation after knee injury, in terms of temperature variations and surface shape. It is based on the intersection of rapid color segmentation and homogeneous region segmentation, to which a Laplacian of a Gaussian filter is applied. While rapid color segmentation enables to properly detect the observed core of swollen area, homogeneous region segmentation identifies possible inflammation zones, combining homogeneous grey level and hue area segmentation. The hybrid segmentation algorithm compares the potential inflammation regions partially detected by each method to identify overlapping areas. Noise filtering and edge segmentation are then applied to common zones in order to segment the swelling surfaces of the injury. Experimental results on images of a patient with anterior cruciate ligament sprain show the improved performance of the hybrid algorithm with respect to its separated components. The main contribution of this work is a meaningful automatic segmentation of abnormal skin temperature variations on infrared thermography images of knee injury swelling.

  16. Involvement of water channels in synaptic vesicle swelling.

    PubMed

    Jeremic, Aleksandar; Cho, Won Jin; Jena, Bhanu P

    2005-10-01

    Vesicle swelling is critical for secretion; however, the underlying mechanism of synaptic vesicle (SV) swelling is unknown. A G alphai3-phospholipase A2 (PLA2)-mediated involvement of the water channel aquaporin-1 (AQP1) in the regulation of secretory vesicle swelling in the exocrine pancreas has been previously reported. In the present study, the association and involvement of water channels in SV swelling was explored. Results from the study demonstrate that water channels AQP1 and AQP6, and the heterotrimeric Go protein are associated with SVs and participate in their swelling.

  17. Mineralogy-swelling potential relationships for expansive shales

    USGS Publications Warehouse

    Olsen, H.W.; Krosley, L.; Nelson, K.; Chabrillat, S.; Goetz, A.F.H.; Noe, D.C.

    2000-01-01

    The extent to which mineralogy and swelling potential is correlated in the expansive clays and shales is studied. Sites are selected in Cretaceous shales, including Pierre Shale, that are uplifted into steeply dipping strata near the foothills of the Rocky Mountains. Swelling potentials are obtained on limited suites of samples with conventional and labor-intensive schemes including Seed and Chen's schemes, and with swell-consolidation measurements in response to saturation, consolidation, and rebound in an oedometer. The results showing the percent total smectite provide a useful index of swelling potential concept defined by Seed and correlates well with the swelling potential indices developed by Seed, Chen, and McKeen.

  18. Modelling the swelling assay for aquaporin expression.

    PubMed

    Pickard, William F

    2008-12-01

    The standard method of assaying the water transporting capability of a putative aquaporin-like entity is to express that entity in a cell of normally low water permeability and to measure the enhancement of swelling when the cell is subjected to hypo-osmotic shock. Because of the heterogeneous nature of cytoplasm, the interplay of advection and diffusion, and the coupling of internal and external media via a semipermeable elastic membrane, even simplified mathematical models can be difficult to resolve. This class of diffusion problem seems to have been but little studied. In this paper, the cell and its surround are at first modelled as perfectly-mixed phases separated by an ideal semipermeable membrane with vanishingly small elastic modulus; and the time course of swelling is evaluated analytically. This time course was found to be non-exponential, but such unexpected behavior should not seriously affect the traditional interpretation of experimental results because its short time limit is linear as in the traditional model; and normally only short time data are available. Next, the simplifications of diffusive equilibrium and of vanishing elastic modulus are examined. It is shown that diffusive equilibrium will be true only when diffusive movement of osmolyte is rather faster than the swelling and that this will probably not be the case for many assays. On the other hand, it should often be possible to neglect the elastic modulus. Finally, a more comprehensive model is formulated for a spherical cell in a hypotonic medium and the swelling behavior described in terms as a moving boundary problem (This type of moving boundary problem is often called a Stefan problem [ http://en.wikipedia.org/wiki/Stefan_problem ]) in which two phases containing diffusive osmolyte are separated by a weakly-elastic ideally-semipermeable membrane, the water flux across which is linear in the osmolality difference across it. This type of behavior was evaluated numerically by finite

  19. Cellulose nanocrystal interactions probed by thin film swelling to predict dispersibility

    NASA Astrophysics Data System (ADS)

    Reid, Michael S.; Villalobos, Marco; Cranston, Emily D.

    2016-06-01

    The production of well-dispersed reinforced polymer nanocomposites has been limited due to poor understanding of the interactions between components. Measuring the cohesive particle-particle interactions and the adhesive particle-polymer interactions is challenging due to nanoscale dimensions and poor colloidal stability of nanoparticles in many solvents. We demonstrate a new cohesive interaction measurement method using cellulose nanocrystals (CNCs) as a model system; CNCs have recently gained attention in the composites community due to their mechanical strength and renewable nature. Multi-wavelength surface plasmon resonance spectroscopy (SPR) was used to monitor the swelling of CNC thin films to elucidate the primary forces between CNCs. This was achieved by measuring swelling in situ in water, acetone, methanol, acetonitrile, isopropanol, and ethanol and relating the degree of swelling to solvent properties. Films swelled the most in water where we estimate 1.2-1.6 nm spacings between CNCs (or 4-6 molecular layers of water). Furthermore, a correlation was found between film swelling and the solvent's Hildebrand solubility parameter (R2 = 0.9068). The hydrogen bonding component of the solubility parameters was more closely linked to swelling than the polar or dispersive components. The films remained intact in all solvents, and using DLVO theory we have identified van der Waals forces as the main cohesive interaction between CNCs. The trends observed suggest that solvents (and polymers) alone are not sufficient to overcome CNC-CNC cohesion and that external energy is required to break CNC agglomerates. This work not only demonstrates that SPR can be used as a tool to measure cohesive particle-particle interactions but additionally advances our fundamental understanding of CNC interactions which is necessary for the design of cellulose nanocomposites.The production of well-dispersed reinforced polymer nanocomposites has been limited due to poor understanding of

  20. Effect of laser and/or electron beam irradiation on void swelling in SUS316L austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Yang, Subing; Yang, Zhanbing; Wang, Hui; Watanabe, Seiichi; Shibayama, Tamaki

    2017-05-01

    Large amounts of void swelling still limit the application of austenitic stainless steels in nuclear reactors due to radiation-induced lattice point defects. In this study, laser and/or beam irradiation was conducted in a temperature range of 573-773 K to explore the suppression of void swelling. The results show that during sequential laser-electron beam irradiation, the void nucleation is enhanced because of the vacancy clusters and void nuclei formed under pre-laser irradiation, causing greater void swelling than single electron beam irradiation. However, simultaneous laser-electron dual-beam irradiation exhibits an obvious suppression effect on void swelling due to the enhanced recombination between interstitials and vacancies in the temperature range of 573-773 K; especially at 723 K, the swelling under simultaneous dual-beam irradiation is 0.031% which is only 22% of the swelling under electron beam irradiation (0.137%). These results provide new insight into the suppression of void swelling during irradiation.

  1. “Spontaneous” CSF Fistula due to Transtegmental Brain Herniation in Combination with Signs of Increased Intracranial Pressure and Petrous Bone Hyperpneumatization: An Illustrative Case Report

    PubMed Central

    Rivera, Diones; Fermin-Delgado, Rafael; Stoeter, Peter

    2014-01-01

    Background and Importance Transtegmental brain herniation into the petrous bone is a rare cause of rhinoliquorrhea. Our case presents a combination of several typical clinical and imaging findings illustrating the ongoing etiologic discussion of such cerebrospinal fluid (CSF) fistulas. Clinical Presentation A 53-year-old man presented with nasal discharge after a strong effort to suppress coughing. Imaging revealed a transtegmental herniation of parts of the inferior temporal gyrus into the petrous bone and in addition a combination of signs of chronically increased intracranial pressure and a hyperpneumatization of the petrous bone. The fistula was closed by a middle cranial fossa approach. Conclusion The case illustrates the two main predisposing factors for development of petrous bone CSF fistulas: increased intracranial pressure and thinning of the tegmental roof due to extensive development of air cells. Because the CSF leakage repair does not change the underlying cause, patients have to be informed about the possibility of developing increased intracranial pressure and recurrences of brain herniations at other sites. PMID:25485224

  2. "Spontaneous" CSF Fistula due to Transtegmental Brain Herniation in Combination with Signs of Increased Intracranial Pressure and Petrous Bone Hyperpneumatization: An Illustrative Case Report.

    PubMed

    Rivera, Diones; Fermin-Delgado, Rafael; Stoeter, Peter

    2014-12-01

    Background and Importance Transtegmental brain herniation into the petrous bone is a rare cause of rhinoliquorrhea. Our case presents a combination of several typical clinical and imaging findings illustrating the ongoing etiologic discussion of such cerebrospinal fluid (CSF) fistulas. Clinical Presentation A 53-year-old man presented with nasal discharge after a strong effort to suppress coughing. Imaging revealed a transtegmental herniation of parts of the inferior temporal gyrus into the petrous bone and in addition a combination of signs of chronically increased intracranial pressure and a hyperpneumatization of the petrous bone. The fistula was closed by a middle cranial fossa approach. Conclusion The case illustrates the two main predisposing factors for development of petrous bone CSF fistulas: increased intracranial pressure and thinning of the tegmental roof due to extensive development of air cells. Because the CSF leakage repair does not change the underlying cause, patients have to be informed about the possibility of developing increased intracranial pressure and recurrences of brain herniations at other sites.

  3. Counterion-induced swelling of ionic microgels

    NASA Astrophysics Data System (ADS)

    Denton, Alan R.; Tang, Qiyun

    2016-10-01

    Ionic microgel particles, when dispersed in a solvent, swell to equilibrium sizes that are governed by a balance between electrostatic and elastic forces. Tuning of particle size by varying external stimuli, such as pH, salt concentration, and temperature, has relevance for drug delivery, microfluidics, and filtration. To model swelling of ionic microgels, we derive a statistical mechanical theorem, which proves exact within the cell model, for the electrostatic contribution to the osmotic pressure inside a permeable colloidal macroion. Applying the theorem, we demonstrate how the distribution of counterions within an ionic microgel determines the internal osmotic pressure. By combining the electrostatic pressure, which we compute via both Poisson-Boltzmann theory and molecular dynamics simulation, with the elastic pressure, modeled via the Flory-Rehner theory of swollen polymer networks, we show how deswelling of ionic microgels with increasing concentration of particles can result from a redistribution of counterions that reduces electrostatic pressure. A linearized approximation for the electrostatic pressure, which proves remarkably accurate, provides physical insight and greatly eases numerical calculations for practical applications. Comparing with experiments, we explain why soft particles in deionized suspensions deswell upon increasing concentration and why this effect may be suppressed at higher ionic strength. The failure of the uniform ideal-gas approximation to adequately account for counterion-induced deswelling below close packing of microgels is attributed to neglect of spatial variation of the counterion density profile and the electrostatic pressure of incompletely neutralized macroions.

  4. Anisotropic swelling behavior of the cornea.

    PubMed

    Matsuura, Toyoaki; Ikeda, Hitoe; Idota, Naokazu; Motokawa, Ryuhei; Hara, Yoshiaki; Annaka, Masahiko

    2009-12-24

    The phase equilibrium property and structural and dynamical properties of pig cornea were studied by macroscopic observation of swelling behavior, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) under various conditions. It was found that the corneal gel collapses into a compact state isotropically or anisotropically depending on the external conditions. The corneal gel collapses uniformly into a compact state at a temperature above 55 degrees C because of the denaturation of collagen, whereas it collapses along an axis parallel to the optic axis with increasing NaCl concentration. Anisotropic deswelling was also observed during desiccation. SAXS measurements revealed that the periodicity of the collagen fiber of the cornea does not change even at higher NaCl concentration, which indicates that hydration and dehydration resulting from changes in salt concentration simply cause swelling and deswelling of the glycosaminoglycan (GAG), which is located between the regular two-dimensional lattices of collagen fibers, which obliges the change in thickness. From observations of the dynamics of light scattered by the corneal gel, intensity autocorrelation functions that revealed two independent diffusion coefficients were obtained. Divergent behavior in the measured total scattered light intensities and diffusion coefficients with varying temperature was observed. That is, a slowing of the dynamic modes accompanied by increased "static" scattered intensities was observed. This is indicative of the occurrence of a phase transition as a function of temperature.

  5. A comparison between mechano-electrochemical and biphasic swelling theories for soft hydrated tissues.

    PubMed

    Wilson, W; van Donkelaar, C C; Huyghe, J M

    2005-02-01

    Biological tissues like intervertebral discs and articular cartilage primarily consist of interstitial fluid, collagen fibrils and negatively charged proteoglycans. Due to the fixed charges of the proteoglycans, the total ion concentration inside the tissue is higher than in the surrounding synovial fluid (cation concentration is higher and the anion concentration is lower). This excess of ion particles leads to an osmotic pressure difference, which causes swelling of the tissue. In the last decade several mechano-electrochemical models, which include this mechanism, have been developed. As these models are complex and computationally expensive, it is only possible to analyze geometrically relatively small problems. Furthermore, there is still no commercial finite element tool that includes such a mechano-electrochemical theory. Lanir (Biorheology, 24, pp. 173-187, 1987) hypothesized that electrolyte flux in articular cartilage can be neglected in mechanical studies. Lanir's hypothesis implies that the swelling behavior of cartilage is only determined by deformation of the solid and by fluid flow. Hence, the response could be described by adding a deformation-dependent pressure term to the standard biphasic equations. Based on this theory we developed a biphasic swelling model. The goal of the study was to test Lanir's hypothesis for a range of material properties. We compared the deformation behavior predicted by the biphasic swelling model and a full mechano-electrochemical model for confined compression and 1D swelling. It was shown that, depending on the material properties, the biphasic swelling model behaves largely the same as the mechano-electrochemical model, with regard to stresses and strains in the tissue following either mechanical or chemical perturbations. Hence, the biphasic swelling model could be an alternative for the more complex mechano-electrochemical model, in those cases where the ion flux itself is not the subject of the study. We propose

  6. Association between reduced expression of hippocampal glucocorticoid receptors and cognitive dysfunction in a rat model of traumatic brain injury due to lateral head acceleration.

    PubMed

    Gao, Wei; Xu, Hongyu; Liang, Ming; Huang, Jason H; He, Xiaosheng

    2013-01-15

    Expression of hippocampal glucocorticoid receptors (GRs) and spatial learning and memory were observed in rat model of diffuse traumatic brain injury (TBI) due to lateral head acceleration with an aim at investigating the relation between GRs expression and cognitive deficits. Immunohistochemical staining, Western blotting, and RT-PCR indicated that down-regulation of GRs expression occurred in the hippocampus among TBI-rats which demonstrated reduced performance of learning and memory in Morris water maze. As the GRs expression bounced up, the cognitive function approached to normal. It is concluded that reduced expression of hippocampal GRs was closely associated with learning and memory deficits in TBI-rats. Hippocampal GRs was involved in the biochemical mechanisms of cognitive deficits after TBI. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. Brain death due to abdominal compartment syndrome caused by massive venous bleeding in a patient with a stable pelvic fracture: report of a case.

    PubMed

    Hagiwara, Akiyoshi; Fukushima, Hideki; Inoue, Tetsuya; Murata, Atsuo; Shimazaki, Shuji

    2004-01-01

    We report a rare case in which abdominal compartment syndrome resulting from venous hemorrhaging developed in a patient with stable pelvic fractures, resulting in a fatal outcome. An 84-year-old man with mild pelvic fractures developed hypovolemic shock and underwent transcatheter arterial embolization. He became hemodynamically stable after the procedure, but became hypotensive for the second time 11 h after admission. Urinary bladder pressure rose to 32 mmHg from 4-7 mmHg. Rebleeding from the pelvis with the development of abdominal compartment syndrome was suspected. Repeated transcatheter arterial embolization and laparotomy were performed; however, 1 min into the procedure, both pupils symmetrically dilated and the light reflex disappeared. This case suggests that brain death can sometimes occur due to abdominal compartment syndrome.

  8. Assessment of the structural brain network reveals altered connectivity in children with unilateral cerebral palsy due to periventricular white matter lesions

    PubMed Central

    Pannek, Kerstin; Boyd, Roslyn N.; Fiori, Simona; Guzzetta, Andrea; Rose, Stephen E.

    2014-01-01

    Background Cerebral palsy (CP) is a term to describe the spectrum of disorders of impaired motor and sensory function caused by a brain lesion occurring early during development. Diffusion MRI and tractography have been shown to be useful in the study of white matter (WM) microstructure in tracts likely to be impacted by the static brain lesion. Aim The purpose of this study was to identify WM pathways with altered connectivity in children with unilateral CP caused by periventricular white matter lesions using a whole-brain connectivity approach. Methods Data of 50 children with unilateral CP caused by periventricular white matter lesions (5–17 years; manual ability classification system [MACS] I = 25/II = 25) and 17 children with typical development (CTD; 7–16 years) were analysed. Structural and High Angular Resolution Diffusion weighted Images (HARDI; 64 directions, b = 3000 s/mm2) were acquired at 3 T. Connectomes were calculated using whole-brain probabilistic tractography in combination with structural parcellation of the cortex and subcortical structures. Connections with altered fractional anisotropy (FA) in children with unilateral CP compared to CTD were identified using network-based statistics (NBS). The relationship between FA and performance of the impaired hand in bimanual tasks (Assisting Hand Assessment—AHA) was assessed in connections that showed significant differences in FA compared to CTD. Results FA was reduced in children with unilateral CP compared to CTD. Seven pathways, including the corticospinal, thalamocortical, and fronto-parietal association pathways were identified simultaneously in children with left and right unilateral CP. There was a positive relationship between performance of the impaired hand in bimanual tasks and FA within the cortico-spinal and thalamo-cortical pathways (r2 = 0.16–0.44; p < 0.05). Conclusion This study shows that network-based analysis of structural connectivity can identify alterations

  9. Assessment of the structural brain network reveals altered connectivity in children with unilateral cerebral palsy due to periventricular white matter lesions.

    PubMed

    Pannek, Kerstin; Boyd, Roslyn N; Fiori, Simona; Guzzetta, Andrea; Rose, Stephen E

    2014-01-01

    Cerebral palsy (CP) is a term to describe the spectrum of disorders of impaired motor and sensory function caused by a brain lesion occurring early during development. Diffusion MRI and tractography have been shown to be useful in the study of white matter (WM) microstructure in tracts likely to be impacted by the static brain lesion. The purpose of this study was to identify WM pathways with altered connectivity in children with unilateral CP caused by periventricular white matter lesions using a whole-brain connectivity approach. Data of 50 children with unilateral CP caused by periventricular white matter lesions (5-17 years; manual ability classification system [MACS] I = 25/II = 25) and 17 children with typical development (CTD; 7-16 years) were analysed. Structural and High Angular Resolution Diffusion weighted Images (HARDI; 64 directions, b = 3000 s/mm(2)) were acquired at 3 T. Connectomes were calculated using whole-brain probabilistic tractography in combination with structural parcellation of the cortex and subcortical structures. Connections with altered fractional anisotropy (FA) in children with unilateral CP compared to CTD were identified using network-based statistics (NBS). The relationship between FA and performance of the impaired hand in bimanual tasks (Assisting Hand Assessment-AHA) was assessed in connections that showed significant differences in FA compared to CTD. FA was reduced in children with unilateral CP compared to CTD. Seven pathways, including the corticospinal, thalamocortical, and fronto-parietal association pathways were identified simultaneously in children with left and right unilateral CP. There was a positive relationship between performance of the impaired hand in bimanual tasks and FA within the cortico-spinal and thalamo-cortical pathways (r(2) = 0.16-0.44; p < 0.05). This study shows that network-based analysis of structural connectivity can identify alterations in FA in unilateral CP, and that these

  10. Validation of Models of Electromagnetic Fields Induced by Ocean Swell Using Bottom Mounted Sensor Systems

    NASA Astrophysics Data System (ADS)

    Bole, T.; Glover, B. A.

    2016-12-01

    The motion of conducting seawater through Earth's magnetic field induces secondary electromagnetic fields. Ocean waves, including internal waves and surface waves, produce electric and magnetic fields in this fashion. We use dynamical pressure from an absolute pressure unit deployed in approximately 100 meters of water to estimate water column velocities for observed ocean swell. These velocities serve as input to dynamical models for prediction of electric and magnetic fields due to observed swell. The predicted fields are compared favorably to observed electric and magnetic fields, providing in-situ model validation of the models.

  11. Heat-flow anomaly and residual topography in the Mascarene hotspot swell (Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Chiozzi, P.; Verdoya, M.

    2017-03-01

    We review the sea-bottom heat-flow determinations and present a new heat-flow observation on the Mauritius island, which is part of the long-lived Reunion hotspot track. The marine heat flow is on average 66 ± 11 mW m-2 and is consistent with the on-land value of 61 ± 18 mW m-2 found in Mauritius. Since these values do not significantly deviate from the reference cooling-plate model, lithosphere erosion does not seem a likely mechanism for the swell formation. The lack of significant reheating due to a mantle plume impacting the lithosphere base is confirmed by thermal modelling. Moreover, the coherency between on-land and marine data is argument against advective redistribution of heat near the axis of the swell. We also analyse the large-scale features of the ocean lithosphere, which are not simply a function of the plate cooling and can reflect variations in mantle dynamic topography. The predicted topography variation along the swell shows amplitude and wavelength comparable to other hotspots. Both the topographic swell magnitude and the wavelength increase northwards with the increase of the age of volcanism. The estimated flux of material from the mantle follows the same trend, being larger in the northern part of the swell. The result that residual topography and the buoyancy flux are smaller at the active volcano of Reunion could be evidence that the activity of the plume has decreased with time.

  12. Hygroscopic swelling and shrinkage of latewood cell wall micropillars reveal ultrastructural anisotropy.

    PubMed

    Rafsanjani, Ahmad; Stiefel, Michael; Jefimovs, Konstantins; Mokso, Rajmund; Derome, Dominique; Carmeliet, Jan

    2014-06-06

    We document the hygroscopic swelling and shrinkage of the central and the thickest secondary cell wall layer of wood (named S2) in response to changes in environmental humidity using synchrotron radiation-based phase contrast X-ray tomographic nanoscopy. The S2 layer is a natural fibre-reinforced nano-composite polymer and is strongly reactive to water. Using focused ion beam, micropillars with a cross section of few micrometres are fabricated from the S2 layer of the latewood cell walls of Norway spruce softwood. The thin neighbouring cell wall layers are removed to prevent hindering or restraining of moisture-induced deformation during swelling or shrinkage. The proposed experiment intended to get further insights into the microscopic origin of the anisotropic hygro-expansion of wood. It is found that the swelling/shrinkage strains are highly anisotropic in the transverse plane of the cell wall, larger in the normal than in the direction parallel to the cell wall's thickness. This ultrastructural anisotropy may be due to the concentric lamellation of the cellulose microfibrils as the role of the cellulose microfibril angle in the transverse swelling anisotropy is negligible. The volumetric swelling of the cell wall material is found to be substantially larger than the one of wood tissues within the growth ring and wood samples made of several growth rings. The hierarchical configuration in wood optimally increases its dimensional stability in response to a humid environment with higher scales of complexity.

  13. Swelling behavior of chitosan hydrogels in ionic liquid-water binary systems.

    PubMed

    Spinks, Geoffrey M; Lee, Chang Kee; Wallace, Gordon G; Kim, Sun I; Kim, Seon Jeong

    2006-10-24

    The swelling behavior of chitosan hydrogels in ionic liquid-water binary systems was studied using hydrophilic room-temperature ionic liquids (RTILs) to elucidate the swelling mechanism of chitosan hydrogels. No penetration of RTIL into a dry chitosan material was observed. Swelling was achieved by soaking in water-RTIL binary mixtures, with larger swelling observed at higher water contents. In one instance, the binary mixture was acidic and produced larger than expected swelling due to the dissociation of the amine groups in the chitosan. The equilibrium binary system content behavior of the chitosan hydrogels depended upon the amount of free water, which is a measure of the number of water molecules that do not interact with the ionic liquid. After evaporation of water, remnant RTIL remained in the chitosan network and hardness testing indicated a plasticization effect, suggesting that the RTIL molecularly mixed with the chitosan. Chitosan hydrogels containing only RTIL were prepared by dropping pure RTIL onto a fully preswollen hydrogel followed by water evaporation. This method may be a useful means for preparing air-stable swollen chitosan gels.

  14. A Diagnostic Approach to Recurrent Orofacial Swelling: A Retrospective Study of 104 Patients.

    PubMed

    Miest, Rachel Y; Bruce, Alison J; Comfere, Nneka I; Hadjicharalambous, Elena; Endly, Dawnielle; Lohse, Christine M; Rogers, Roy S

    2017-07-01

    To identify patients evaluated in an outpatient setting at our institution with a presentation of recurrent orofacial swelling and to review the spectrum of causes to outline a diagnostic approach. A retrospective study of 104 patients with more than 1 episode of orofacial swelling lasting for more than 5 days identified through a keyword search of the electronic health record from January 2, 2000, through July 5, 2011. Patients were categorized according to final cause of orofacial swelling: idiopathic orofacial granulomatosis, solid facial edema due to rosacea and acne vulgaris, Crohn disease, contact dermatitis, sarcoidosis, exfoliative cheilitis, lichen planus, actinic cheilitis, cheilitis glandularis, lymphedema, miscellaneous, and multifactorial. Granulomatous inflammation was noted on biopsy in 40 of 85 patients (47%). Oral involvement was associated with Crohn disease (P<.001), and facial and periorbital swelling was associated with solid facial edema in the setting of rosacea and acne vulgaris (P<.001). The broad range of diagnoses responsible for recurrent orofacial swelling underscores the diagnostic challenge and importance of a thorough multidisciplinary evaluation to identify underlying causes. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  15. The relation between composition and swelling in clays

    USGS Publications Warehouse

    Foster, Margaret D.

    1955-01-01

    The phenomenon of swelling is associated with the hydration of clays; however, all clays do not swell when hydrated. those of the kaolin group, for example, exhibit little or no swelling on hydration. Sodiwm montmoillonite, on the other hand, characteristically swells in water to many times its dry volume. Calcium and magnesium montmorillonite and the hydrous micas, or so called illites, fall between these two extremes in swelling properties, but are, in general, much closer to kaolinite than to sodium montmorillonite in their increase in volume on hydration. These differences in the swelling characteristics of different clays may be related to their chemical composition, to the kind and degree of isomorphous replacements in their structure, and to the amount and nature of their associated exchangeable cations. 

  16. Investigation on Swells of the East China Sea

    NASA Astrophysics Data System (ADS)

    Tao, Aifeng; Wu, Chao

    2017-04-01

    In the recent decades, more and more human activities, including different kinds of marine structures and large ships, have been present in the East China Sea. It is necessary to fasten our attentions on the marine safety issues, particularly on the extreme waves. Because it has been known that the density of extreme waves may increase with Typhoon in the future with the global climate changing. The extreme waves can be induced not only by Typhoon in summer, but also by East Asian cold waves in winter for this special sea area. And the swells also can be very dangerous because the swells may result in the resonance with floating structures, including the ships. Focusing on the investigation of swells in the East China Sea, the hindcast for waves in the past ten years will be performed by the numerical model Wave Watch III based on the historical climate data. The numerical calculation domain covers the whole North West Pacific. Then the swells will be separated and analyzed from the simulated wave fields. Both the characteristics and the generation mechanisms of the swells will be investigated. Particularly, the swells, which propagating across the Ryukyu chain from east to west, will be analyzed in details. We used the CCMP & Myers wind data to run the WW3 model and reproduced the global wave fields in 2010-2014. After separating swell and wind sea from mixed waves, we studied the spatial and temporal distribution of swell in East China Sea and the formation mechanism of swell in East China Sea.The significant wave heights of swells in the East China Sea are mainly distributed in the 0.1-2.5m, the interval with the highest frequency of occurrence is 0.1-0.5m, and the proportion is about 50%. The spectrum peak periods of swells are mainly distributed in the 4-15s, the interval with the highest frequency of occurrence is 9-15s., and the proportion is about 25%. In terms of spatial distribution swells increase gradually from the offshore to deep sea, and also

  17. Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent

    NASA Astrophysics Data System (ADS)

    Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin

    2008-02-01

    Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

  18. Release of Water Soluble Drugs from Dynamically Swelling POLY(2-HYDROXYETHYL Methacrylate - CO - Methacrylic Acid) Hydrogels.

    NASA Astrophysics Data System (ADS)

    Kou, Jim Hwai-Cher

    In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic understanding of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling

  19. On the cation dependence of interlamellar and interparticular water and swelling in smectite clays.

    PubMed

    Salles, F; Bildstein, O; Douillard, J M; Jullien, M; Raynal, J; Van Damme, H

    2010-04-06

    filled when the mesopores start to fill up. This implies that the swelling observed in the mesopores for Li and Na samples is due to an osmotic swelling. For the other samples, it is difficult to conclude definitively. Furthermore, we determine the different proportion of water (interlayer water and mesopore water) present in our samples by the original combination of (1) X-ray diffraction data, (2) the pore size distribution obtained by thermoporometry, and (3) recent adsorption isotherm results. It is found that the interlayer space is never completely filled by water at the studied relative humidity values for all samples except for the Cs sample.

  20. Safety and Efficacy of Cerebrolysin in Infants with Communication Defects due to Severe Perinatal Brain Insult: A Randomized Controlled Clinical Trial

    PubMed Central

    Deifalla, Shaymaa M.; El-Houssinie, Moustafa; Mokbel, Somaia A.

    2016-01-01

    Background and Purpose The neuroregenerative drug Cerebrolysin has demonstrated efficacy in improving cognition in adults with stroke and Alzheimer's disease. The aim of this study was to determine the efficacy and safety of Cerebrolysin in the treatment of communication defects in infants with severe perinatal brain insult. Methods A randomized placebo-controlled clinical trial was conducted in which 158 infants (age 6-21 months) with communication defects due to severe perinatal brain insult were enrolled; 120 infants completed the study. The Cerebrolysin group (n=60) received twice-weekly Cerebrolysin injections of 0.1 mL/kg body weight for 5 weeks (total of ten injections). The placebo group (n=60) received the same amount and number of normal saline injections. Results The baseline Communication and Symbolic-Behavior-Scale-Developmental Profile scores were comparable between the two groups. After 3 months, the placebo group exhibited improvements in the social (p<0.01) and speech composite (p=0.02) scores, with 10% and 1.5% increases from baseline, respectively. The scores of the Cerebrolysin group changed from concern to no concern, with increases of 65.44%, 45.54%, 358.06%, and 96.00% from baseline in the social (p<0.001), speech (p<0.001), symbolic (p<0.001), and total (p<0.001) scores. Conclusions Cerebrolysin dramatically improved infants' communication especially symbolic behavior which positively affected social interaction. These findings suggest that cerebrolysin may be an effective and feasible way equivalent to stem cell therapy. PMID:26365023

  1. Swelling of CFx and CFx(Au) films

    NASA Astrophysics Data System (ADS)

    D'Addabbo, A.; Valentini, A.; Convertino, A.

    2000-02-01

    The article reports on the swelling phenomenon, observed in the presence of acetone vapors in undoped and Au doped Teflon-like films. The Au presence enhances the degree of the swelling of the Teflon. Moreover, the metal grains embedded in the insulating matrix are used to detect swelling with an electrical method. A conductance model of metal embedded dielectric materials is used to describe the conductance variations with the polymer volume change.

  2. Tracking the attenuation and nonbreaking dissipation of swells using altimeters

    NASA Astrophysics Data System (ADS)

    Jiang, Haoyu; Stopa, Justin E.; Wang, He; Husson, Romain; Mouche, Alexis; Chapron, Bertrand; Chen, Ge

    2016-02-01

    A method for systematically tracking swells across oceanic basins is developed by taking advantage of high-quality data from space-borne altimeters and wave model output. The evolution of swells is observed over large distances based on 202 swell events with periods ranging from 12 to 18 s. An empirical attenuation rate of swell energy of about 4 × 10-7 m-1 is estimated using these observations, and the nonbreaking energy dissipation rates of swells far away from their generating areas are also estimated using a point source model. The resulting acceptance range of nonbreaking dissipation rates is -2.5 to 5.0 × 10-7 m-1, which corresponds to a dissipation e-folding scales of at least 2000 km for steep swells, to almost infinite for small-amplitude swells. These resulting rates are consistent with previous studies using in-situ and synthetic aperture radar (SAR) observations. The frequency dispersion and angular spreading effects during swell propagation are discussed by comparing the results with other studies, demonstrating that they are the two dominant processes for swell height attenuation, especially in the near field. The resulting dissipation rates from these observations can be used as a reference for ocean engineering and wave modeling, and for related studies such as air-sea and wind-wave-turbulence interactions.

  3. Involvement of vH+-ATPase in synaptic vesicle swelling

    PubMed Central

    Shin, Leah; Basi, Nirukti; Jeremic, Aleksandar; Lee, Jin-Sook; Cho, Won Jin; Chen, ZhiHui; Abu-Hamdah, Rania; Oupicky, David; Jena, Bhanu P

    2010-01-01

    Secretory vesicle swelling is central to cell secretion, however the underlying mechanism of vesicle swelling, particularly synaptic vesicles, is not completely understood. The Gαi3-PLA2-mediated involvement of water channel AQP-1 in the regulation of secretory vesicle swelling in exocrine pancreas, and the Gαo-mediated AQP-6 involvement in synaptic vesicle swelling in neurons, has previously been reported. Furthermore, the role of vH+-ATPase in neurotransmitter transport into synaptic vesicles, has also been shown. Using nanometer scale precision measurements of isolated synaptic vesicles, the present study reports for the first time, the involvement of vH+-ATPase in GTP-Gαo-mediated synaptic vesicle swelling. Results from this study, demonstrate that the GTP-Gαo-mediated vesicle swelling is vH+-ATPase–dependent, and pH sensitive. Zeta potential measurements of isolated synaptic vesicles further demonstrate, a bafilomycin-sensitive vesicle acidification, following the GTP-Gαo-induced swelling stimulus. Since water channels are bidirectional, and the vH+-ATPase inhibitor bafilomycin decreases both the volume of isolated synaptic vesicles and GTP-mastoparan stimulated swelling, suggests vH+-ATPase to be upstream of AQP-6, in the pathway leading from Gαo-stimulated swelling of synaptic vesicles. Vesicle acidification is therefore a prerequisite for AQP-6 mediated gating of water into synaptic vesicles. PMID:19610106

  4. The Initial Water Content Dependent Swelling Behavior of Clayey Soils

    NASA Astrophysics Data System (ADS)

    Samet Öngen, Ali; Abiddin Erguler, Zeynal

    2015-04-01

    The variation in water content is known as a main controlling parameter for many physical and mechanical behaviors of clayey soils, particularly soils found in arid and semi-arid regions. Expansive soils found in such regions are naturally subjected to many volume increase and decrease cycles within unsaturated zone during rainy and dry periods, and thus these soils constitute severe hazard to low-rise light buildings and infrastructures constructed in shallow unsaturated depths. Although the relationships between swelling parameters (swelling pressure and swelling percent) and soils' physical - index properties have been investigated in details in previous researches, the continuous effect of water content on swelling mechanisms of soils is not yet sufficiently studied. The water content of unsaturated zone naturally fluctuates with changes in both seasonal climatic conditions and increasing in depths, and therefore, swelling parameters of a soil within unsaturated soils should not be represented with only one single value. For achieving accurate understanding of swelling behavior at field condition, soils should be subjected to swelling tests by considering different initial water content conditions. Considering requirement for further understanding in water content dependent swelling behavior of soils, a research program was aimed to investigate the effect of initial water content on swelling behavior of soil materials. For this purpose, soils having wide range of physical properties such as grain size distributions, mineralogical composition and consistency limits were collected from different locations in Turkey. To minimize the effect of dry unit weight on swelling behavior of soils, samples prepared at same dry unit weight (14.6 kN/m3) with various initial water contents ranging from 0% to approximately 37% were subjected to swelling tests by using convenient odometer device. Beside these tests, grain size distribution, Atterberg limits and mineralogical

  5. Processes and controls in swelling anhydritic clay rocks

    NASA Astrophysics Data System (ADS)

    Mutschler, Thomas; Blum, Philipp; Butscher, Christoph

    2015-04-01

    Referring to the swelling of anhydritic clay rocks in tunneling, Leopold Müller-Salzburg noted in the third volume on tunneling of his fundamental text book on rock engineering that "a truly coherent explanation of these phenomena is still owing" (Müller-Salzburg 1978, p. 306). This valuation is still true after more than three decades of research in the field of swelling anhydritic clay rocks. One of the reasons is our limited knowledge of the processes involved in the swelling of such rocks, and of the geological, mineralogical, hydraulic, chemical and mechanical controls of the swelling. In this contribution, a review of processes in swelling anhydritic clay rocks and of associated controls is presented. Also numerical models that aim at simulating the swelling processes and controls are included in this review, and some of the remaining open questions are pointed out. By focusing on process-oriented work in this review, the presentation intends to stimulate further research across disciplines in the field of swelling anhydritic clay rocks to finally get a step further in managing the swelling problem in geotechnical engineering projects. Keywords: swelling; anhydritic clay rocks; review

  6. Swelling behaviour of Early Jurassic shales when exposed to water vapour

    NASA Astrophysics Data System (ADS)

    Houben, Maartje; Barnhoorn, Auke; Peach, Colin; Drury, Martyn

    2017-04-01

    The presence of water in mudrocks has a largely negative impact on production of gas, due to the fact that water causes swelling of the rock. Removing the water from the mudrock on the other hand could potentially shrink the rock and increase the matrix permeability. Investigation of the swelling/shrinkage behaviour of the rock during exposure to water vapour is of key importance in designing and optimizing unconventional production strategies. We have used outcrop samples of the Whitby Mudstone and the Posidonia shale [1], potential unconventional sources for gas in North-western Europe, to measure the swelling and shrinkage behaviour. Subsamples, 1 mm cubes, were prepared by the Glass Workshop at Utrecht University using a high precision digitally controlled diamond wafering saw cooled by air. The mm cubes were then exposed to atmospheres with different relative humidities either in an Environmental Scanning Electron Microscope (ESEM) or in a 3D dilatometer. So that the sample responses to exposure of water vapour could be measured. Parallel to the bedding we found a swelling strain between 0.5 and 1.5 %, perpendicular to the bedding though swelling strain varied between 1 and 3.5%. Volumetric swelling strain varied between 1 and 2% at a maximum relative humidity of 95%. Volumetric swelling strains measured in the Early Toarcian Shales are similar to the ones found in coal [2], where the results suggest that it might be possible to increase permeability in the reservoir by decreasing the in-situ water activity due to shrinkage of the matrix. [1] M.E. Houben, A. Barnhoorn, L. Wasch, J. Trabucho-Alexandre, C. J. Peach, M.R. Drury (2016). Microstructures of Early Jurassic (Toarcian) shales of Northern Europe, International Journal of Coal Geology, 165, 76-89. [2] Jinfeng Liu, Colin J. Peach, Christopher J. Spiers (2016). Anisotropic swelling behaviour of coal matrix cubes exposed to water vapour: Effects of relative humidity and sample size, International Journal of

  7. ATP release during cell swelling activates a Ca(2+)-dependent Cl(-) current by autocrine mechanism in mouse hippocampal microglia.

    PubMed

    Murana, E; Pagani, F; Basilico, B; Sundukova, M; Batti, L; Di Angelantonio, S; Cortese, B; Grimaldi, A; Francioso, A; Heppenstall, P; Bregestovski, P; Limatola, C; Ragozzino, D

    2017-06-23

    Microglia cells, resident immune cells of the brain, survey brain parenchyma by dynamically extending and retracting their processes. Cl(-) channels, activated in the cellular response to stretch/swelling, take part in several functions deeply connected with microglia physiology, including cell shape changes, proliferation, differentiation and migration. However, the molecular identity and functional properties of these Cl(-) channels are largely unknown. We investigated the properties of swelling-activated currents in microglial from acute hippocampal slices of Cx3cr1 (+/GFP) mice by whole-cell patch-clamp and imaging techniques. The exposure of cells to a mild hypotonic medium, caused an outward rectifying current, developing in 5-10 minutes and reverting upon stimulus washout. This current, required for microglia ability to extend processes towards a damage signal, was carried mainly by Cl(-) ions and dependent on intracellular Ca(2+). Moreover, it involved swelling-induced ATP release. We identified a purine-dependent mechanism, likely constituting an amplification pathway of current activation: under hypotonic conditions, ATP release triggered the Ca(2+)-dependent activation of anionic channels by autocrine purine receptors stimulation. Our study on native microglia describes for the first time the functional properties of stretch/swelling-activated currents, representing a key element in microglia ability to monitor the brain parenchyma.

  8. Numerical Simulation Of The Treatment Of Soil Swelling Using Grid Geocell Columns

    NASA Astrophysics Data System (ADS)

    Fattah, Mohammed Y.; Al-Omari, Raid R.; Ali, Haifaa A.

    2015-06-01

    In this paper, a method for the treatment of the swelling of expansive soil is numerically simulated. The method is simply based on the embedment of a geogrid (or a geomesh) in the soil. The geogrid is extended continuously inside the volume of the soil where the swell is needed to be controlled and orientated towards the direction of the swell. Soils with different swelling potentials are employed: bentonite base-Na and bentonite base-Ca samples in addition to kaolinite mixed with bentonite. A numerical analysis was carried out by the finite element method to study the swelling soil's behavior and investigate the distribution of the stresses and pore water pressures around the geocells beneath the shallow footings. The ABAQUS computer program was used as a finite element tool, and the soil is represented by the modified Drucker-Prager/cap model. The geogrid surrounding the geocell is assumed to be a linear elastic material throughout the analysis. The soil properties used in the modeling were experimentally obtained. It is concluded that the degree of saturation and the matric suction (the negative pore water pressure) decrease as the angle of friction of the geocell column material increases due to the activity of the sand fill in the dissipation of the pore water pressure and the acceleration of the drainage through its function as a drain. When the plasticity index and the active depth (the active zone is considered to be equal to the overall depth of the clay model) increase, the axial movement (swelling movement) and matric suction, as a result of the increase in the axial forces, vary between this maximum value at the top of the layer and the minimum value in the last third of the active depth and then return to a consolidation at the end of the depth layer.

  9. Effect of fungal decay on the hygroscopic thickness swelling rate of lignocellulosic filler-polyolefin biocomposites

    NASA Astrophysics Data System (ADS)

    Kord, B.; Hosseinihashemi, S. Kh.

    2014-01-01

    The influence of fungal decay on the hygroscopic thickness swelling rate of lignocellulosic filler-polyolefin biocomposites has been investigated. Composites based on polypropylene (PP), bagasse fiber (BF), and a coupling agent (PP-g-MA) were made by melt compounding and injection molding. The weigt ratio of BF to PP was controlled at 60/40 for all blends. The amount of coupling agent was fixed at 2% for all formulations. The samples obtained were exposed to the action of brown-rot (Coniophora puteana) and white-rot (Trametes versicolor) fungi for 8, 12, and 16 weeks according to the Kolle-flask method. The thickness swelling of the samples was evaluated by immersing them in water at room temperature for several weeks. The morphology of the composites was characterized using the scanning electron microscopy (SEM). The results indicated that the fungal decay had an adverse affect on the dimensional stability of BF/PP composites due to an increase in the thickness swelling rate. The thickness swelling of white-rotted samples was higher than that of brown-rotted ones and control samples. Also, the thickness swelling of BF/PP composites increased with increasing time of fungal decay. In addition, after 16 weeks of exposure to white-rot fungi, the composites exhibited a higher parameter of swelling rate K SR than control samples. The K SR of the composites was influenced both by the type of rooting and the exposure time. Furthermore, the SEM micrographs showed that the extent of degradation increased with growing exposure time to fungi.

  10. Kinetics of dextran crosslinking by epichlorohydrin: a rheometry and equilibrium swelling study.

    PubMed

    Emami Meybodi, Zahraalsadat; Imani, Mohammad; Atai, Mohammad

    2013-02-15

    Curing behavior and gel properties of dextran are investigated during its crosslinking by epichlorohydrin (ECH) using rheometry and equilibrium swelling studies. Each ECH/anhydroglucose unit of different molar ratio (0.16-0.99) was added to a known volume of aqueous dextran solution (25%, w/w) in the presence of sodium hydroxide (1.2-3.6 M) as a catalyst. Gel point was investigated as a function of the reactants concentration. The rheological behavior of the curing gels was evaluated using a rheokinetic model. Swelling behavior of the cured, cylindrical specimens was also studied gravimetrically. Increasing NaOH and ECH concentrations significantly increased the crosslinking reaction rate leading to shorter gel points, which was attributed to more ionization of hydroxyl functional groups of dextran due to higher NaOH concentrations. Degree of swelling vs. the reaction time was decreased sharply as a direct function of increasing NaOH and ECH concentrations up to certain levels, which then leveled off. In contrast, higher NaOH concentrations increased the swelling ratio probably due to the alkaline induced degradation of dextran chains.

  11. Swelling and thermodynamic studies of temperature responsive 2-hydroxyethyl methacrylate/itaconic acid copolymeric hydrogels prepared via gamma radiation

    NASA Astrophysics Data System (ADS)

    Tomić, Simonida L. J.; Mićić, Maja M.; Filipović, Jovanka M.; Suljovrujić, Edin H.

    2007-08-01

    The copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were synthesized by gamma radiation induced radical polymerization. Swelling and thermodynamic properties of PHEMA and copolymeric P(HEMA/IA) hydrogels with different IA contents (2, 3.5 and 5 mol%) were studied in a wide pH and temperature range. Initial studies of so-prepared hydrogels show interesting pH and temperature sensitivity in swelling and drug release behavior. Special attention was devoted to temperature investigations around physiological temperature (37 °C), where small changes in temperature significantly influence swelling and drug release of these hydrogels. Due to maximum swelling of hydrogels around 40 °C, the P(HEMA/IA) hydrogel containing 5 mol% of IA without and with drug-antibiotic (gentamicin) were investigated at pH 7.40 and in the temperature range 25-42 °C, in order to evaluate their potential for medical applications.

  12. Hardness and swelling behaviour of epoxidized natural rubber/recycled acrylonitrile-butadiene rubber (ENR 50/NBRr) blends

    NASA Astrophysics Data System (ADS)

    Ahmad, Hazwani Syaza; Ismail, Hanafi; Rashid, Azura A.

    2017-07-01

    This recent work is to investigate the hardness and swelling behaviour of epoxidized natural rubber/recycled acrylonitrile-butadiene rubber (ENR 50/NBRr) blends. ENR 50/NBRr blends were prepared by two-roll mills with five different loading of NBRr from 5 to 35 phr. Results indicated that the hardness of ENR 50/NBRr blends increased as recycled NBR increased due to the improvement in crosslink density of the blends. Increasing NBRr content gives ENR 50/NBRr blends better resistance towards swelling. Higher degree of crosslinking will increase the swelling resistance and reduce the penetration of toluene into the blends. The presence of polar group in ENR 50 and NBRr give better hardness properties and swelling behaviour of the ENR 50/NBRr blends compared to the NR/NBRr blends.

  13. Apolipoprotein E3/E3 genotype decreases the risk of pituitary dysfunction after traumatic brain injury due to various causes: preliminary data.

    PubMed

    Tanriverdi, Fatih; Taheri, Serpil; Ulutabanca, Halil; Caglayan, Ahmet Okay; Ozkul, Yusuf; Dundar, Munis; Selcuklu, Ahmet; Unluhizarci, Kursad; Casanueva, Felipe F; Kelestimur, Fahrettin

    2008-09-01

    Traumatic brain injury (TBI) is a devastating public health problem which may result in hypopituitarism. However, the mechanisms and the risk factors responsible for hypothalamo-pituitary dysfunction due to TBI are still unclear. Although APO E is one of the most abundant protein in hypothalamo-pituitary region, there is no study investigating the relation between APO E polymorphism and TBI-induced hypopituitarism. This study was undertaken to determine whether APO E genotypes modulate the pituitary dysfunction risk after TBI due to various causes, including traffic accident, boxing, and kickboxing. Ninety-three patients with TBI (mean age, 30.61 +/- 1.25 years) and 27 healthy controls (mean age, 29.03 +/- 1.70 years) were included in the study. Pituitary functions were evaluated, and APO E genotypes (E2/E2; E3/E3; E4/E4; E2/E3; E2/E4; E3/E4) were screened. Twenty-four of 93 subjects (25.8%) had pituitary dysfunction after TBI. The ratio of pituitary dysfunction was significantly lower in subjects with APO E3/E3 (17.7%) than the subjects without APO E3/E3 genotype (41.9%; p = 0.01), and the corresponding odds ratio was 0.29 (95% confidence interval [CI], 0.11-0.78). In conclusion, this study provides strong evidence for the first time that APO E polymorphism is associated with the development of TBI-induced pituitary dysfunction. Present data demonstrated that APO E3/E3 genotype decreases the risk of hypopituitarism after TBI. The demonstration of the association between the APO E polymorphism and TBI may provide a new point of view in this field and promote further studies.

  14. Clinical and diagnostic approach to patients with hypopituitarism due to traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), and ischemic stroke (IS).

    PubMed

    Karamouzis, Ioannis; Pagano, Loredana; Prodam, Flavia; Mele, Chiara; Zavattaro, Marco; Busti, Arianna; Marzullo, Paolo; Aimaretti, Gianluca

    2016-06-01

    The hypothalamic-pituitary dysfunction attributable to traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhage (SAH), and ischemic stroke (IS) has been lately highlighted. The diagnosis of TBI-induced-hypopituitarism, defined as a deficient secretion of one or more pituitary hormones, is made similarly to the diagnosis of classical hypopituitarism because of hypothalamic/pituitary diseases. Hypopituitarism is believed to contribute to TBI-associated morbidity and to functional and cognitive final outcome, and quality-of-life impairment. Each pituitary hormone must be tested separately, since there is a variable pattern of hormone deficiency among patients with TBI-induced-hypopituitarism. Similarly, the SAH and IS may lead to pituitary dysfunction although the literature in this field is limited. The drive to diagnose hypopituitarism is the suspect that the secretion of one/more pituitary hormone may be subnormal. This suspicion can be based upon the knowledge that the patient has an appropriate clinical context in which hypopituitarism can be present, or a symptom known as caused by hypopituitarism. Hypopituitarism should be diagnosed as a combination of low peripheral and inappropriately normal/low pituitary hormones although their basal evaluation may be not distinctive due to pulsatile, circadian, or situational secretion of some hormones. Evaluation of the somatotroph and corticotroph axes require dynamic stimulation test (ITT for both axes, GHRH + arginine test for somatotroph axis) in order to clearly separate normal from deficient responses.

  15. Skeletogenesis in the swell shark Cephaloscyllium ventriosum.

    PubMed

    Eames, B Frank; Allen, Nancy; Young, Jonathan; Kaplan, Angelo; Helms, Jill A; Schneider, Richard A

    2007-05-01

    Extant chondrichthyans possess a predominantly cartilaginous skeleton, even though primitive chondrichthyans produced bone. To gain insights into this peculiar skeletal evolution, and in particular to evaluate the extent to which chondrichthyan skeletogenesis retains features of an osteogenic programme, we performed a histological, histochemical and immunohistochemical analysis of the entire embryonic skeleton during development of the swell shark Cephaloscyllium ventriosum. Specifically, we compared staining properties among various mineralizing tissues, including neural arches of the vertebrae, dermal tissues supporting oral denticles and Meckel's cartilage of the lower jaw. Patterns of mineralization were predicted by spatially restricted alkaline phosphatase activity earlier in development. Regarding evidence for an osteogenic programme in extant sharks, a mineralized tissue in the perichondrium of C. ventriosum neural arches, and to a lesser extent a tissue supporting the oral denticle, displayed numerous properties of bone. Although we uncovered many differences between tissues in Meckel's cartilage and neural arches of C. ventriosum, both elements impart distinct tissue characteristics to the perichondral region. Considering the evolution of osteogenic processes, shark skeletogenesis may illuminate the transition from perichondrium to periosteum, which is a major bone-forming tissue during the process of endochondral ossification.

  16. Electrostatic swelling of bicontinuous cubic lipid phases.

    PubMed

    Tyler, Arwen I I; Barriga, Hanna M G; Parsons, Edward S; McCarthy, Nicola L C; Ces, Oscar; Law, Robert V; Seddon, John M; Brooks, Nicholas J

    2015-04-28

    Lipid bicontinuous cubic phases have attracted enormous interest as bio-compatible scaffolds for use in a wide range of applications including membrane protein crystallisation, drug delivery and biosensing. One of the major bottlenecks that has hindered exploitation of these structures is an inability to create targeted highly swollen bicontinuous cubic structures with large and tunable pore sizes. In contrast, cubic structures found in vivo have periodicities approaching the micron scale. We have been able to engineer and control highly swollen bicontinuous cubic phases of spacegroup Im3m containing only lipids by (a) increasing the bilayer stiffness by adding cholesterol and (b) inducing electrostatic repulsion across the water channels by addition of anionic lipids to monoolein. By controlling the composition of the ternary mixtures we have been able to achieve lattice parameters up to 470 Å, which is 5 times that observed in pure monoolein and nearly twice the size of any lipidic cubic phase reported previously. These lattice parameters significantly exceed the predicted maximum swelling for bicontinuous cubic lipid structures, which suggest that thermal fluctuations should destroy such phases for lattice parameters larger than 300 Å.

  17. Skeletogenesis in the swell shark Cephaloscyllium ventriosum

    PubMed Central

    Eames, B Frank; Allen, Nancy; Young, Jonathan; Kaplan, Angelo; Helms, Jill A; Schneider, Richard A

    2007-01-01

    Extant chondrichthyans possess a predominantly cartilaginous skeleton, even though primitive chondrichthyans produced bone. To gain insights into this peculiar skeletal evolution, and in particular to evaluate the extent to which chondrichthyan skeletogenesis retains features of an osteogenic programme, we performed a histological, histochemical and immunohistochemical analysis of the entire embryonic skeleton during development of the swell shark Cephaloscyllium ventriosum. Specifically, we compared staining properties among various mineralizing tissues, including neural arches of the vertebrae, dermal tissues supporting oral denticles and Meckel's cartilage of the lower jaw. Patterns of mineralization were predicted by spatially restricted alkaline phosphatase activity earlier in development. Regarding evidence for an osteogenic programme in extant sharks, a mineralized tissue in the perichondrium of C. ventriosum neural arches, and to a lesser extent a tissue supporting the oral denticle, displayed numerous properties of bone. Although we uncovered many differences between tissues in Meckel's cartilage and neural arches of C. ventriosum, both elements impart distinct tissue characteristics to the perichondral region. Considering the evolution of osteogenic processes, shark skeletogenesis may illuminate the transition from perichondrium to periosteum, which is a major bone-forming tissue during the process of endochondral ossification. PMID:17451531

  18. Swelling kinetics of microgels embedded in a polyacrylamide hydrogel matrix.

    PubMed

    Huang, Na; Guan, Ying; Zhu, X X; Zhang, Yongjun

    2014-06-23

    Composite hydrogels--macroscopic hydrogels with embedded microgel particles--are expected to respond to external stimuli quickly because microgels swell much faster than bulky gels. In this work, the kinetics of the pH-induced swelling of a composite hydrogel are studied using turbidity measurements. The embedded microgel is a pH- and thermosensitive poly(N-isopropylacrylamide-co-acrylic acid) microgel and the hydrogel matrix is polyacrylamide. A rapid pH-induced swelling of the embedded microgel particles is observed, confirming that composite hydrogels respond faster than ordinary hydrogels. However, compared with the free microgels, the swelling of the embedded microgel is much slower. Diffusion of OH(-) into the composite hydrogel film is identified as the main reason for the slow swelling of the embedded microgel particles, as the time of the pH-induced swelling of this film is comparable to that of OH(-) diffusion into the film. The composition of the hydrogel matrix does not significantly change the characteristic swelling time of the composite hydrogel film. However, the swelling pattern of the film changes with composition of the hydrogel matrix.

  19. Sexual swellings advertise female quality in wild baboons.

    PubMed

    Domb, L G; Pagel, M

    2001-03-08

    The females of many Old World primate species produce prominent and conspicuous swellings of the perineal skin around the time of ovulation. These sexual swellings have been proposed to increase competition among males for females or to increase the likelihood of a female getting fertilized, by signalling either a female's general reproductive status, or the timing of her ovulation. Here we show that sexual swellings in wild baboons reliably advertise a female's reproductive value over her lifetime, in accordance with a theoretical model of honest signalling. Females with larger swellings attained sexual maturity earlier, produced both more offspring and more surviving offspring per year than females with smaller swellings, and had a higher overall proportion of their offspring survive. Male baboons use the size of the sexual swelling to determine their mating effort, fighting more aggressively to consort females with larger swellings, and spending more time grooming these females. Our results document an unusual case of a sexually selected ornament in females, and show how males, by mating selectively on the basis of the size of the sexual swelling, increase their probability of mating with females more likely to produce surviving offspring.

  20. Scrotal Lymphangioma – A Rare Cause of Scrotal Swelling

    PubMed Central

    Nain Rattan, Kamal; S Malik, Vivek; Garsa, Vipin

    2013-01-01

    Lymphangioma is an extremely rare cause of scrotal swelling. We are reporting such a tumor in a one and half year old child presenting with a painless, progressive scrotal swelling. The mass was evaluated and excised completely. Histopathology confirmed it as Lymphangioma. PMID:23277887

  1. New constraints on the Hawaiian swell origin using wavelet analysis of the geoid to topography ratio

    NASA Astrophysics Data System (ADS)

    Cadio, C.; Ballmer, M.; Panet, I.; Ribe, N.; Diament, M.

    2012-04-01

    Analyzing the formation of hotspot swells, including the shallowness around the Hawaiian Islands, is critical for understanding the origin of intraplate volcanism and the underlying geodynamical processes. Two main hypotheses for the origin of this swell are generally considered: thermal lithospheric thinning, and dynamical support by a convective ascending plume. A major goal of these models is to quantitatively explain the two important characteristics of the Hawaiian swell: its topography and the corresponding geoid anomaly. In simple models of isostatic compensation, the geoid-to-topography ratio (GTR) is linearly related to the depth of the compensating mass; therefore it is often considered as a fundamental parameter to assess swell support mechanisms. According to previous work, the observed GTR has been reported to range from 4 to 5 m/km. The corresponding apparent compensation depth is about 45 km, which is shallower than predicted by the dynamic support model. However, analysis of the data processing methods shows that the applied bandpass filters to retain only characteristic wavelengths of the swell topography and geoid, cannot completely remove the signal due to loading of the volcanic edifices and related lithospheric flexure. In order to resolve these issues, we apply a continuous wavelet transform, which allows us to retrieve lateral variations of the GTR at each spatial scale. A series of synthetic tests based on different geodynamic models clearly indicates that by efficiently filtering the unwanted contributions, our approach is able to estimate the proper GTR of the Hawaiian swell. A high GTR of 8 m/km is recovered on the current hotspot location. Therefore, for the first time, the recovered GTR agrees with realistic geodynamic models of the Hawaiian plume. Accordingly, the thermal rejuvenation model can be ruled out by our analysis. Instead, the swell as a whole is shown to be mainly supported dynamically by the uprising Hawaiian plume

  2. Sex steroids inhibit osmotic swelling of retinal glial cells.

    PubMed

    Neumann, Florian; Wurm, Antje; Linnertz, Regina; Pannicke, Thomas; Iandiev, Ianors; Wiedemann, Peter; Reichenbach, Andreas; Bringmann, Andreas

    2010-04-01

    Osmotic swelling of glial cells may contribute to the development of retinal edema. We investigated whether sex steroids inhibit the swelling of glial somata in acutely isolated retinal slices and glial cells of the rat. Superfusion of retinal slices or cells from control animals with a hypoosmolar solution did not induce glial swelling, whereas glial swelling was observed in slices of postischemic and diabetic retinas. Progesterone, testosterone, estriol, and 17beta-estradiol prevented glial swelling with half-maximal effects at approximately 0.3, 0.6, 6, and 20 microM, respectively. The effect of progesterone was apparently mediated by transactivation of metabotropic glutamate receptors, P2Y1, and adenosine A1 receptors. The data suggest that sex steroids may inhibit cytotoxic edema in the retina.

  3. Ischemia-induced endothelial cell swelling and mitochondrial dysfunction are attenuated by cinnamtannin D1, green tea extract, and resveratrol in vitro.

    PubMed

    Panickar, Kiran S; Qin, Bolin; Anderson, Richard A

    2015-10-01

    Polyphenols possess antioxidant and anti-inflammatory properties. Oxidative stress (OS) and inflammation have been implicated in the pathogenesis of cytotoxic brain edema in cerebral ischemia. In addition, OS and pro-inflammatory cytokines also damage the endothelial cells and the neurovascular unit. Endothelial cell swelling may contribute to a leaky blood-brain barrier which may result in vasogenic edema in the continued presence of the existing cytotoxic edema. We investigated the protective effects of polyphenols on cytotoxic cell swelling in bEND3 endothelial cultures subjected to 5 hours oxygen-glucose deprivation (OGD). A polyphenol trimer from cinnamon (cinnamtannin D1), a polyphenol-rich extract from green tea, and resveratrol prevented the OGD-induced rise in mitochondrial free radicals, cell swelling, and the dissipation of the inner mitochondrial membrane potential. Monocyte chemoattractant protein (also called CCL2), a chemokine, but not tumor necrosis factor-α or interleukin-6, augmented the cell swelling. This effect of monochemoattractant protein 1-1 was attenuated by the polyphenols. Cyclosporin A, a blocker of the mitochondrial permeability transition pore, did not attenuate cell swelling but BAPTA-AM, an intracellular calcium chelator did, indicating a role of [Ca(2+)]i but not the mPT in cell swelling. These results indicate that the polyphenols reduce mitochondrial reactive oxygen species and subsequent cell swelling in endothelial cells following ischemic injury and thus may reduce brain edema and associated neural damage in ischemia. One possible mechanism by which the polyphenols may attenuate endothelial cell swelling is through the reduction in [Ca(2+)]i.

  4. Mitochondrial free radical overproduction due to respiratory chain impairment in the brain of a mouse model of Rett syndrome: protective effect of CNF1.

    PubMed

    De Filippis, Bianca; Valenti, Daniela; de Bari, Lidia; De Rasmo, Domenico; Musto, Mattia; Fabbri, Alessia; Ricceri, Laura; Fiorentini, Carla; Laviola, Giovanni; Vacca, Rosa Anna

    2015-06-01

    Rett syndrome (RTT) is a pervasive neurodevelopmental disorder mainly caused by mutations in the X-linked MECP2 gene associated with severe intellectual disability, movement disorders, and autistic-like behaviors. Its pathogenesis remains mostly not understood and no effective therapy is available. High circulating levels of oxidative stress markers in patients and the occurrence of oxidative brain damage in MeCP2-deficient mouse models suggest the involvement of oxidative stress in RTT pathogenesis. However, the molecular mechanism and the origin of the oxidative stress have not been elucidated. Here we demonstrate that a redox imbalance arises from aberrant mitochondrial functionality in the brain of MeCP2-308 heterozygous female mice, a condition that more closely recapitulates that of RTT patients. The marked increase in the rate of hydrogen peroxide generation in the brain of RTT mice seems mainly produced by the dysfunctional complex II of the mitochondrial respiratory chain. In addition, both membrane potential generation and mitochondrial ATP synthesis are decreased in RTT mouse brains when succinate, the complex II respiratory substrate, is used as an energy source. Respiratory chain impairment is brain area specific, owing to a decrease in either cAMP-dependent phosphorylation or protein levels of specific complex subunits. Further, we investigated whether the treatment of RTT mice with the bacterial protein CNF1, previously reported to ameliorate the neurobehavioral phenotype and brain bioenergetic markers in an RTT mouse model, exerts specific effects on brain mitochondrial function and consequently on hydrogen peroxide production. In RTT brains treated with CNF1, we observed the reactivation of respiratory chain complexes, the rescue of mitochondrial functionality, and the prevention of brain hydrogen peroxide overproduction. These results provide definitive evidence of mitochondrial reactive oxygen species overproduction in RTT mouse brain and

  5. Irradiation creep due to SIPA under cascade damage conditions

    SciTech Connect

    Woo, C.H.; Garner, F.A.; Holt, R.A.

    1992-12-31

    This paper derives the relationships between void swelling and irradiation creep due to Stress-Induced Preferred Absorption (SIPA) and SIPA-Induced Growth (SIG) under cascade damage conditions in an irradiated pressurized tube. It is found that at low swelling rates irradiation creep is a major contribution to the total diametral strain rate of the tube, whereas at high swelling rates the creep becomes a minor contribution. The anisotropy of the corresponding dislocation structure is also predicted to decline as the swelling rate increases. The theoretical predictions are found to agree very well with experimental results.

  6. Water uptake and swelling hysteresis in a nafion thin film measured with neutron reflectometry.

    PubMed

    Kalisvaart, W Peter; Fritzsche, Helmut; Mérida, Walter

    2015-05-19

    Water uptake and swelling in a thin (∼15 nm) Nafion film on SiO2 native oxide on a Si wafer is studied as a function of relative humidity (8-97%) at room temperature and as a function of temperature (25-60 °C) at 97% relative humidity by neutron reflectometry. This is the first report on the behavior of thin Nafion films at elevated temperatures and high humidity. Large hysteresis is observed during the temperature cycle. The observed swelling strain in the film at 60 °C is 48% as compared to the as-deposited state, which is far above any previously observed trend at room temperature. A small decrease in the average SLD suggests that part of the additional swelling is due to thermal expansion, but the estimated D2O/SO3 ratio also increases by 70%. Half of the "excess" absorption and 73% of the additional swelling are retained during cooling back to room temperature. The results provide new insights into the dynamics of Nafion on nanometer scales under fuel cell operating conditions.

  7. Propionate induces cell swelling and K+ accumulation in shark rectal gland

    SciTech Connect

    Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.; Booz, G.W.; Kleinzeller, A. )

    1989-08-01

    Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same time Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by {sup 86}Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes.

  8. Optical measurement and modelling of parison sag and swell in blow moulding

    NASA Astrophysics Data System (ADS)

    Béreaux, Yves; Charmeau, Jean-Yves; Balcaen, Jean

    2011-05-01

    Blow moulding is a process whereby a cylindrical parison is extruded first, then pinched between the two halves of a mould and, finally, blown into the product. Parison size and shape result from complex interactions between mandrel and die geometries, processing parameters and viscoelastic properties of the polymeric material. Moreover, parison size changes with time due to sag. An innovative, contactless and online measurement technique of the parison is shown to be an effective tool to measure precisely parison diameter and thickness and to capture dimensional changes with time. This technique employs laser lighting of the parison and hinges on the refractive properties of molten polymer. Images taken with a digital camera are processed to give a precise measurement of diameter and thickness, at different time step during extrusion. Thus, parison swell and sag have been recorded for a commercial HDPE. Influence of processing parameters such as the rotational screw speed or die gap width can be brought forward. Thickness swell is found to possess a different behaviour from diameter swell. Swell is a purely viscoelastic phenomenon, therefore requiring a numerical modelling with an integral viscoelastic constitutive equation. On the other hand, sag has been measured and could be modelled from a Newtonian perspective using one dimensional convected coordinates. A sagging susceptibility coefficient of the polymer is deduced.

  9. Swelling agent adopted decal transfer method for membrane electrode assembly fabrication

    NASA Astrophysics Data System (ADS)

    Cho, Doo Hee; Lee, So Young; Shin, Dong Won; Hwang, Doo Sung; Lee, Young Moo

    2014-07-01

    The decal transfer method is regarded as an effective membrane electrode assembly (MEA) fabrication method for industrial processes due to the improved adhesion between the catalyst layers and the hydrocarbon membrane. In this study, three swelling agents (ethanol, 1,5-pentanediol and glycerol) are introduced to the conventional decal methods in order to improve both the transfer ratio of electrodes on the membrane surface and the electrochemical properties. These swelling agents affect the surface energy differences between the swollen catalyst layer and the membrane substrate. Swelling agents also change the structure of the catalyst layer during the preparation (hot pressing) of the MEA. Changing the catalyst layer structure by introducing swelling agents diminishes the charge transfer resistance and internal resistances of MEAs. These improved electrochemical properties lead to the remarkably enhanced single cell performance of a SPAES MEA of 1380 mA cm-2 at 0.6 V, compared to a SPAES MEA fabricated by the conventional decal method (500 mA cm-2).

  10. Effect of groundwater chemistry on the swelling behavior of a Ca-bentonite for deep geological repository

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Chuan; Huang, Wei-Hsing

    The swelling properties of buffer material for high level radioactive waste repository in a near-field environment are of particular importance for achieving the low permeability sealing function. In this study, the free swelling behavior of a potential buffer material Zhisin clay is evaluated under simulated groundwater conditions such as immersion in NaCl, CaCl2, and Na2SO4 solutions at various concentrations. Experimental results indicate that Zhisin clay, being a Ca-bentonite, exhibits reduced swelling strain in salt solutions. The amount of decrease in swelling strain upon saline water intrusion is affected by both the type and concentration of electrolyte. At the same concentration, the swelling strains in CaCl2 solution are lower than those in NaCl solution due to the quasi-crystals formed in the presence of calcium ions. Also, the swells in Na2SO4 solution are found to be lower than those in NaCl solution. This is attributed to the precipitation of CaSO4, which acts as binding agent and results in aggregation of clay particles.

  11. Chocolate swelling during storage caused by fat or moisture migration.

    PubMed

    Svanberg, L; Lorén, N; Ahrné, L

    2012-11-01

    Quantification of swelling in dark chocolate subjected to fat or moisture migration was conducted using a new method based on confocal chromatic displacement sensor. The nondestructive method allowed for the height profile of dark chocolate samples to be scanned with a sensitivity of ± 2.8 μm. By performing multiple scans on each sample prior to and after being subjected to fat or moisture migration, the induced swelling could be quantified. Applying the new method on confectionery systems revealed that fat and moisture migration generate different swelling behavior/kinetics in dark chocolate during storage. Moisture migration resulted in a rapid swelling once a water activity of 0.8 was reached in the chocolate, probably by interaction and absorption of moisture by the particulate solids. Fat migration also affected the swelling behavior in chocolate, possibly by inducing phase transitions in the continuous cocoa butter phase. Migrating fat also proved to induce a more pronounced swelling than the same amount of absorbed moisture which further consolidated that the observed swelling caused by fat or moisture migration is a result of significant different mechanisms.

  12. Osmotic swelling of polyacrylate hydrogels in physiological salt solutions.

    PubMed

    Horkay, F; Tasaki, I; Basser, P J

    2000-01-01

    The swelling behavior of fully neutralized sodium polyacrylate gels was investigated in aqueous solutions of alkali metal (LiCl, NaCl, KCl, CsCl) and alkaline earth metal salts (CaCl2, SrCl2, BaCl2). The total salt concentration and the ratio of monovalent to divalent cations were varied in the biologically significant range. It is found that the concentrations of both monovalent and divalent cations vary continuously and smoothly in the gel despite the abrupt change in the gel volume. The individual elastic, mixing, and ionic contributions to the free energy of the gel were separately determined as a function of the degree of network swelling to elucidate the thermodynamics of swelling. Shear modulus measurements performed at different Ca2+ concentrations suggest that Ca2+ does not form stable cross-links between the polymer chains. At low and moderate swelling ratios the concentration dependence of the shear modulus follows a power law behavior, G variation of phi n, with n = 0.34 +/- 0.03. At high swelling degrees, however, the shear modulus increases with increasing swelling. The value of the Flory-Huggins interaction parameter, chi, determined from osmotic swelling pressure and shear modulus measurements, strongly depends on the ionic composition of the equilibrium solution and increases with increasing Ca2+ concentration.

  13. Drainage and Landscape Evolution in the Bighorn Basin Accompanying Advection of the Yellowstone Hotspot Swell Through North America

    NASA Astrophysics Data System (ADS)

    Guerrero, E. F.; Meigs, A.

    2012-12-01

    basin is an ideal location to quantify long wavelength dynamic topography due to its low relief. Long river profiles streams that are transverse to the topographic swell in the basin suggest a transient advective signal preserved as profile knickpoints. Abandoned strath terraces, stream piracy, drainage reorganization, and lateral channel migration within the Bighorn Basin are all consistent indicators of the advection of a topographic swell. However, the lack of a high-resolution absolute age chronology precludes us from attributing the primary landscape and drainage forcing to climate change or dynamic topography. Our future work will focus on the timing of geomorphic and river profile evolution to disentangle competing effects of topographic advection, climate, and other factors.

  14. Seasonality of Ankle Swelling: Population Symptom Reporting Using Google Trends.

    PubMed

    Liu, Fangwei; Allan, G Michael; Korownyk, Christina; Kolber, Michael; Flook, Nigel; Sternberg, Harvey; Garrison, Scott

    2016-07-01

    In our experience, complaints of ankle swelling are more common in summer, typically from patients with no obvious cardiovascular disease. Surprisingly, this observation has never been reported. To objectively establish this phenomenon, we sought evidence of seasonality in the public's Internet searches for ankle swelling. Our data, obtained from Google Trends, consisted of all related Google searches in the United States from January 4, 2004, to January 26, 2016. Consistent with our expectations and confirmed by similar data for Australia, Internet searches for information on ankle swelling are highly seasonal (highest in midsummer), with seasonality explaining 86% of search volume variability.

  15. Swelling and Contraction of Phaseolus Hypocotyl Mitochondria 1

    PubMed Central

    Earnshaw, M. J.; Truelove, B.

    1968-01-01

    Isolated Phaseolus mitochondria will swell spontaneously in buffered KCl and contract with an oxidizable substrate or ATP + Mg2+. The conditions under which the mitochondria are swollen affect subsequent contraction, substrate oxidation and ion accumulation, but not their oxidative phosphorylation ability. Bovine serum albumin reduces the rate of swelling and promotes substrate oxidation, contraction and ion accumulation. Swelling of these mitochondria is associated with the release of malic dehydrogenase and a loss of membrane integrity. The beneficial effects of bovine serum albumin in preserving the energy linked functions of Phaseolus mitochondria is discussed. PMID:16656729

  16. Orbital sarcoidosis presenting as diffuse swelling of the lower eyelid.

    PubMed

    Lee, Jeong Kyu; Moon, Nam Ju

    2013-02-01

    The author reports a case of orbital Sarcoidosis in a 70-year-old female that initially presented as diffuse swelling of the lower eyelid. The patient complained of painless swelling of the left lower lid without palpable mass, and a computerized tomography (CT) scan of the orbit was unremarkable. A serum angiotensin converting enzyme level was elevated, and hilar lymphadenopathy was noted on the chest CT. The patient underwent surgical debulking for histologic confirmation, which led to a final diagnosis of sarcoidosis involving the orbital fat. Unexplained chronic eyelid swelling without a mass should be considered a possible ophthalmic manifestation of orbital sarcoidosis.

  17. Neurological and behavioral abnormalities, ventricular dilatation, altered cellular functions, inflammation, and neuronal injury in brains of mice due to common, persistent, parasitic infection

    PubMed Central

    Hermes, Gretchen; Ajioka, James W; Kelly, Krystyna A; Mui, Ernest; Roberts, Fiona; Kasza, Kristen; Mayr, Thomas; Kirisits, Michael J; Wollmann, Robert; Ferguson, David JP; Roberts, Craig W; Hwang, Jong-Hee; Trendler, Toria; Kennan, Richard P; Suzuki, Yasuhiro; Reardon, Catherine; Hickey, William F; Chen, Lieping; McLeod, Rima

    2008-01-01

    Background Worldwide, approximately two billion people are chronically infected with Toxoplasma gondii with largely unknown consequences. Methods To better understand long-term effects and pathogenesis of this common, persistent brain infection, mice were infected at a time in human years equivalent to early to mid adulthood and studied 5–12 months later. Appearance, behavior, neurologic function and brain MRIs were studied. Additional analyses of pathogenesis included: correlation of brain weight and neurologic findings; histopathology focusing on brain regions; full genome microarrays; immunohistochemistry characterizing inflammatory cells; determination of presence of tachyzoites and bradyzoites; electron microscopy; and study of markers of inflammation in serum. Histopathology in genetically resistant mice and cytokine and NRAMP knockout mice, effects of inoculation of isolated parasites, and treatment with sulfadiazine or αPD1 ligand were studied. Results Twelve months after infection, a time equivalent to middle to early elderly ages, mice had behavioral and neurological deficits, and brain MRIs showed mild to moderate ventricular dilatation. Lower brain weight correlated with greater magnitude of neurologic abnormalities and inflammation. Full genome microarrays of brains reflected inflammation causing neuronal damage (Gfap), effects on host cell protein processing (ubiquitin ligase), synapse remodeling (Complement 1q), and also increased expression of PD-1L (a ligand that allows persistent LCMV brain infection) and CD 36 (a fatty acid translocase and oxidized LDL receptor that mediates innate immune response to beta amyloid which is associated with pro-inflammation in Alzheimer's disease). Immunostaining detected no inflammation around intra-neuronal cysts, practically no free tachyzoites, and only rare bradyzoites. Nonetheless, there were perivascular, leptomeningeal inflammatory cells, particularly contiguous to the aqueduct of Sylvius and hippocampus

  18. In-Situ NDT Measurements of Irradiation Induced Swelling PWR Core Internal Components; Phase 3: Correlation of Void Swelling and Material Properties of Austenitic Steels

    SciTech Connect

    I.Balachov; F. Garner; S-G. Kumatori-cho; Y. Isobe

    2004-04-01

    OAK-B135 The objective of the project is to examine and develop in-situ nondestructive testing (NDT) techniques for measuring irradiation induced swelling in the internal components for PWRs. This report documents the third phase effort on establishing experimental correlations of the irradiation induced void swelling and measurable material properties of austenitic steels and, eventually, correlation of swelling and signals of the developed swelling sensors. Experimental stainless steel irradiated at high neutron fluences are presented. Theoretical aspects of the influence of void swelling on electrical resistivity and ultrasound velocity are outlined. Swelling-material properties correlations were recommended for quantitative interpretation of swelling measurements.

  19. Professionals' views on the use of smartphone technology to support children and adolescents with memory impairment due to acquired brain injury.

    PubMed

    Plackett, Ruth; Thomas, Sophie; Thomas, Shirley

    2017-04-01

    Purpose To identify from a health-care professionals' perspective whether smartphones are used by children and adolescents with acquired brain injury as memory aids; what factors predict smartphone use and what barriers prevent the use of smartphones as memory aids by children and adolescents. Method A cross-sectional online survey was undertaken with 88 health-care professionals working with children and adolescents with brain injury. Results Children and adolescents with brain injury were reported to use smartphones as memory aids by 75% of professionals. However, only 42% of professionals helped their clients to use smartphones. The only factor that significantly predicted reported smartphone use was the professionals' positive attitudes toward assistive technology. Several barriers to using smartphones as memory aids were identified, including the poor accessibility of devices and cost of devices. Conclusion Many children and adolescents with brain injury are already using smartphones as memory aids but this is often not facilitated by professionals. Improving the attitudes of professionals toward using smartphones as assistive technology could help to increase smartphone use in rehabilitation. Implications for Rehabilitation Smartphones could be incorporated into rehabilitation programs for young people with brain injury as socially acceptable compensatory aids. Further training and support for professionals on smartphones as compensatory aids could increase professionals' confidence and attitudes in facilitating the use of smartphones as memory aids. Accessibility could be enhanced by the development of a smartphone application specifically designed to be used by young people with brain injury.

  20. Development of an Operational Typhoon Swell Forecasting and Coastal Flooding Early Warning System

    NASA Astrophysics Data System (ADS)

    Fan, Y. M.; Wu, L. C.; Doong, D. J.; Kao, C. C.; Wang, J. H.

    2012-04-01

    Coastal floods and typhoon swells are a consistent threat to oceanfront countries, causing major human suffering and substantial economic losses, such as wrecks, ship capsized, and marine construction failure, etc. Climate change is exacerbating the problem. An early warning system is essential to mitigate the loss of life and property from coastal flooding and typhoon swells. The purpose of this study is to develop a typhoon swell forecasting and coastal flooding early warning system by integrating existing sea-state monitoring technology, numerical ocean forecasting models, historical database and experiences, as well as computer science. The proposed system has capability offering data for the past, information for the present, and for the future. The system was developed for Taiwanese coast due to its frequent threat by typhoons. An operational system without any manual work is the basic requirement of the system. Integration of various data source is the system kernel. Numerical ocean models play the important role within the system because they provide data for assessment of possible typhoon swell and flooding. The system includes regional wave model (SWAN) which nested with the large domain wave model (NWW III), is operationally set up for coastal waves forecasting, especially typhoon swell forecasting before typhoon coming, and the storm surge predicted by a POM model. Data assimilation technology is incorporated for enhanced accuracy. A warning signal is presented when the storm water level that accumulated from astronomical tide, storm surge, and wave-induced run-up exceeds the alarm sea level. This warning system has been in practical use for coastal flooding damage mitigation in Taiwan for years. Example of the system operation during Typhoon Haitung struck Taiwan in 2005 is illustrated in this study.

  1. Dosimetric effects of swelling or shrinking tissue during helical tomotherapy breast irradiation: A phantom study.

    PubMed

    Klepper, Rudolf; Höfel, Sebastian; Botha, Ulrike; Köhler, Peter; Zwicker, Felix

    2014-07-08

    During radiation therapy of the female breast, the actual target volume compared to the planning target volume may change due to swelling or shrinking of the tissue. Under- or overdosage is to be expected, especially when performing IMRT or tomotherapy techniques. The objective of this study is to develop a model-based quantification of these dose effects, with a particular focus on the changes in the surface dose. A cylindrical phantom was used as an artificial surrogate of the human torso. By adding and removing Superflab layers of various thicknesses, both radial breast swelling and shrinking could be simulated. The effects on dose distribution were evaluated using film dosimetry. The results were compared to dose calculations. To estimate the true surface doses, we subtracted the influence of the film material on air measurements. During a swelling of 5, 10, and 15 mm, the planning target volume was consistently underdosed by 2%, 5%, and 7% of the prescribed dose, respectively. Swelling led to reduced dose values of up to 72%, 55%, and 50% at the outer edge of the actual target volume. The measured surface dose decreased successively from 31% to 23%. During shrinking, the dose in the planning target volume increased successively from 100% to 106%. The measured surface doses increased from 29% to 36%. The calculated dose values agreed with the measured values within error limits. During radiotherapy of the female breast, new planning appears to be essential for radial tissue swelling of 5 mm or more because of severe underdosing. Shrinking leads to moderate overdosing and an increased surface dose. In addition, caution is advised when removing bolus material with respect to the planned situation.

  2. Dosimetric effects of swelling or shrinking tissue during helical tomotherapy breast irradiation. A phantom study.

    PubMed

    Klepper, Rudolf; Höfel, Sebastian; Botha, Ulrike; Köhler, Peter; Zwicker, Felix

    2014-07-01

    During radiation therapy of the female breast, the actual target volume compared to the planning target volume may change due to swelling or shrinking of the tissue. Under- or overdosage is to be expected, especially when performing IMRT or tomotherapy techniques. The objective of this study is to develop a model-based quantification of these dose effects, with a particular focus on the changes in the surface dose. A cylindrical phantom was used as an artificial surrogate of the human torso. By adding and removing Superflab layers of various thicknesses, both radial breast swelling and shrinking could be simulated. The effects on dose distribution were evaluated using film dosimetry. The results were compared to dose calculations. To estimate the true surface doses, we subtracted the influence of the film material on air measurements. During a swelling of 5, 10, and 15 mm, the planning target volume was consistently underdosed by 2%, 5%, and 7% of the prescribed dose, respectively. Swelling led to reduced dose values of up to 72%, 55%, and 50% at the outer edge of the actual target volume. The measured surface dose decreased successively from 31% to 23%. During shrinking, the dose in the planning target volume increased successively from 100% to 106%. The measured surface doses increased from 29% to 36%. The calculated dose values agreed with the measured values within error limits. During radiotherapy of the female breast, new planning appears to be essential for radial tissue swelling of 5 mm or more because of severe underdosing. Shrinking leads to moderate overdosing and an increased surface dose. In addition, caution is advised when removing bolus material with respect to the planned situation. PACS numbers: 87.53.Bn, 87.55.dk, 87.55.D.

  3. Swelling-induced and controlled curving in layered gel beams

    PubMed Central

    Lucantonio, A.; Nardinocchi, P.; Pezzulla, M.

    2014-01-01

    We describe swelling-driven curving in originally straight and non-homogeneous beams. We present and verify a structural model of swollen beams, based on a new point of view adopted to describe swelling-induced deformation processes in bilayered gel beams, that is based on the split of the swelling-induced deformation of the beam at equilibrium into two components, both depending on the elastic properties of the gel. The method allows us to: (i) determine beam stretching and curving, once assigned the characteristics of the solvent bath and of the non-homogeneous beam, and (ii) estimate the characteristics of non-homogeneous flat gel beams in such a way as to obtain, under free-swelling conditions, three-dimensional shapes. The study was pursued by means of analytical, semi-analytical and numerical tools; excellent agreement of the outcomes of the different techniques was found, thus confirming the strength of the method. PMID:25383031

  4. Apparatus measures swelling of membranes in electrochemical cells

    NASA Technical Reports Server (NTRS)

    Hennigan, T. J.

    1965-01-01

    Apparatus consisting of a pressure plate unit, four springs of known spring constant and a micrometer measures the swelling and force exerted by the polymer membranes of alkaline electrochemical cells.

  5. Fission induced swelling of U-Mo/Al dispersion fuel

    NASA Astrophysics Data System (ADS)

    Kim, Yeon Soo; Jeong, G. Y.; Park, J. M.; Robinson, A. B.

    2015-10-01

    Fission-induced swelling of U-Mo/Al dispersion fuel meat was measured using microscopy images obtained from post-irradiation examination. The data of reduced-size plate-type test samples and rod-type test samples were employed for this work. A model to predict the meat swelling of U-Mo/Al dispersion fuel was developed. This model is composed of several submodels including a model for interaction layer (IL) growth between U-Mo and Al matrix, a model for IL thickness to IL volume conversion, a correlation for the fission-induced swelling of U-Mo alloy particles, a correlation for the fission-induced swelling of IL, and models of U-Mo and Al consumption by IL growth. The model was validated using full-size plate data that were not included in the model development.

  6. Swelling Behavior of Blended Multilayer Thin Films Using Neutron Reflectivity.

    NASA Astrophysics Data System (ADS)

    Akgun, Bulent; Satija, Sushil; Kim, Hosub; Char, Kookheon

    2008-03-01

    Surface structure and swelling behavior of polyelectrolyte multilayer films of poly (allylamine hydrochloride) (PAH)/poly(sodium 4-styrenesulfonate) (PSS):poly(methacrylic acid) (PMAA) have been studied using X-ray and neutron reflectivity (NR). Samples have been prepared either using spin-assisted self assembly or dip coating. Swelling measurements were done in a chamber by using saturated salt solutions. PSS:PMAA blend composition was varied from pure PSS to pure PMAA to investigate the effect of strong polyelectrolyte on the swelling of the multilayer film. Multilayer films prepared by spin assisted deposition yields well defined films with much smooth interfaces than the films prepared by dip coating. NR results showed that incorporation of strong polyelectrolyte, PSS, into the multilayer decreases the swelling capacity of the film.

  7. Serum albumin induces osmotic swelling of rat retinal glial cells.

    PubMed

    Löffler, Silvana; Wurm, Antje; Kutzera, Franziska; Pannicke, Thomas; Krügel, Katja; Linnertz, Regina; Wiedemann, Peter; Reichenbach, Andreas; Bringmann, Andreas

    2010-03-04

    Edema in the ischemic neural tissue develops by increased vascular permeability associated with extravasation of albumin, and by glial swelling. Here, we show that bovine serum albumin acutely administered to slices of the rat retina causes swelling of glial somata under hypoosmotic conditions. The effect of albumin was dose-dependent, with half-maximal and maximal effects at 10 nM and 1 microM, respectively, and was mediated by activation of transforming growth factor-beta receptor type II, oxidative stress, and the production of arachidonic acid and prostaglandins. Albumin-induced glial swelling was prevented by glutamate and purinergic receptor agonists. The data suggest that serum albumin may induce glial swelling in the presence of osmotic gradients.

  8. Coupled Hydro-Mechanical Model of Bentonite Hydration and Swelling

    NASA Astrophysics Data System (ADS)

    Hancilova, Ilona; Hokr, Milan

    2016-10-01

    This paper deals with the modelling of coupled hydro-mechanical processes at the buffer and host rock interface (bentonite and granite) in the context of the safe disposal of spent nuclear fuel. Granite, as one of the barriers, includes fractures which are the source for hydration of bentonite and its subsequent swelling. It affects the mechanical behaviour and possibly the stability of the whole system. A non-linear solution for the stress-deformation problem with swelling was developed. This solution is coupled with the non-linear diffusion problem (for unsaturated flow). The swelling is defined using a coefficient dependent on water content according to literature data, with the effective Young's modulus decreasing close to zero corresponding to the plastic state. Results confirm the expected non-uniform saturation, swelling, and stresses in bentonite and small contribution to a fracture displacement.

  9. Swelling of ultrathin crosslinked polyamide water purification membranes

    NASA Astrophysics Data System (ADS)

    Chan, Edwin; Stafford, Christopher

    2013-03-01

    Polyamide (PA) ultrathin films represent the state-of-the-art nanofiltration and reverse osmosis membranes used in water desalination. The performance of these materials, such as permselectivity, is intimately linked with extent of swelling of the PA network. Thus, quantifying their swelling behavior would be a useful and simple route to understanding the specific network structural parameters that control membrane performance. In this work, we measure the swelling behavior of PA ultrathin films using X-ray reflectivity as a function of water hydration. By applying the Flory-Rehner theory used to describe the swelling behavior of polymer networks, we quantify the PA network properties including Flory interaction parameter and the monomer units between crosslinks. Finally, we demonstrate application of this measurement approach for characterizing the network properties of different types of PA ultrathin films relevant to water purification and discuss the relationship between network and transport properties. Materials Science and Engineering Division

  10. Mechanically Robust, Negative-Swelling, Mussel-Inspired Tissue Adhesives

    PubMed Central

    Barrett, Devin G.; Bushnell, Grace G.

    2013-01-01

    Most synthetic polymer hydrogel tissue adhesives and sealants swell considerably in physiologic conditions, which can result in mechanical weakening and adverse medical complications. Herein, we describe the synthesis and characterization of mechanically tough zero- or negative-swelling mussel-inspired surgical adhesives based on catechol-modified amphiphilic poly(propylene oxide)-poly(ethylene oxide) block copolymers. The formation, swelling, bulk mechanical, and tissue adhesive properties of the resulting thermosensitive gels were characterized. Catechol oxidation at or below room temperature rapidly resulted in a chemically cross-linked network, with subsequent warming to physiological temperature inducing a thermal hydrophobic transition in the PPO domains and providing a mechanism for volumetric reduction and mechanical toughening. The described approach can be easily adapted for other thermally sensitive block copolymers and cross-linking strategies, representing a general approach that can be employed to control swelling and enhance mechanical properties of polymer hydrogels used in a medical context. PMID:23184616

  11. The Effect of Elasticityon the Extrudate Swell of Molten Polymers

    NASA Astrophysics Data System (ADS)

    Hatzikiriakos, Savvas; Konaganti, Vinod Kumar; UBC Team

    2016-11-01

    The extrudate swell of an industrial grade high molecular weight high-density polyethylene (HDPE) in capillary dies is studied using the integral K-BKZ constitutive model. The non-linear viscoelastic flow properties of the polymer resin are studied for a broad range of large step shear strains and high shear rates using the cone partitioned plate (CPP) geometry of the stress/strain controlled rotational rheometer. This allowed the determination of the rheological parameters accurately, in particular the damping function, which is proven to be the most important in simulating transient flows such as extrudate swell. A series of simulations performed using the integral K-BKZ Wagner model with different values of the Wagner exponent n, ranging from n = 0.15 to 0.5, demonstrates that the extrudate swell predictions are extremely sensitive to the Wagner damping function exponent. Using the correct n - value resulted in extrudate swell predictions that are in excellent agreement with experimental measurements. .

  12. Swelling clad-type plastic optical fiber alkane sensor with multi-layer cladding using electrospray deposition method

    NASA Astrophysics Data System (ADS)

    Nakamura, Akira; Suzuki, Yutaka; Morisawa, Masayuki

    2017-04-01

    In this study, we develop a plastic optical fiber (POF) sensor with a double-layer structure cladding consisting of a swelling polymer lower layer and a dye-doped swelling polymer upper layer. Both cladding layers swell and decrease their refractive indices when exposed to alkane vapor. Then, the structure of the POF sensor changes from leaky to waveguide mode. Therefore, the intensity of transmitted light changes remarkably, depending on the presence of alkane. The absorption of light due to the dye in the upper cladding layer increases the change in transmitted light intensity. In this study, we fabricated a POF sensor by using the electrospray deposition method and examined its response to alkane vapor. The results indicate an improvement in the sensitivity of the POF alkane sensor due to the effect of the double-clad layer.

  13. Generation of Continental Rifts, Basins and Swells by Lithosphere Instabilities

    NASA Astrophysics Data System (ADS)

    Milelli, L.; Fourel, L.; Jaupart, C. P.

    2012-12-01

    blocks of finite size that became unstable due to cooling from above and describe the peculiar horizontal planform that developed. Dynamical behaviour depends on three dimensionless numbers, a Rayleigh number for the unstable block, a buoyancy number that scales the intrinsic density contrast to the thermal one and the aspect ratio of the block. Within the block, instability develops in two different ways in an outer annulus and in an inner region. In the outer annulus, upwellings and downwellings take the form of radial rolls spaced regularly. In the interior region, the planform adopts the more familiar form of polygonal cells. Translated to geological conditions, such instabilities should manifest themselves as linear rifts striking at a right angle to the continent-ocean boundary and an array of domal uplifts, volcanic swells and basins in the continental interior. The laboratory data lead to simple scaling laws for the dimensions and spacings of the convective structures. For the sub-continental lithospheric mantle, these dimensions and distances take values in the 500-1000 km range, close to geological examples. The large intrinsic buoyancy of Archean lithospheric roots prevents this type of instability, which explains why the widespread volcanic activity that currently affects Western Africa is confined to post-Archean domains.

  14. MOELCULAR SIZE EXCLUSION BY SOIL ORGANIC MATERIALS ESTIMATED FROM THEIR SWELLING IN ORGANIC SOLVENTS

    EPA Science Inventory

    A published method previously developed to measure the swelling characteristics of pow dered coal samples has been adapted for swelling measurements on various peat, pollen, chain, and cellulose samples The swelling of these macromolecular materials is the volumetric manifestatio...

  15. Swell and Sea in the Emerging Arctic Ocean

    DTIC Science & Technology

    2014-01-01

    GeophysicalResearchLetters RESEARCHLETTER 10.1002/2014GL059983 Key Points: • Surface waves in the Arctic Ocean increase during periods of sea ice ...fetch in the Arctic , because the swell is regionally driven. This suggests that further reductions in seasonal ice cover in the future will result in... ice sea swell Figure 2. Time series of Arctic Ocean wave conditions. Hourly values for (a) significant wave height, (b) wind speed at 10 m reference

  16. The Effects of Iron Oxidation State on Clay Swelling,

    DTIC Science & Technology

    1983-03-07

    swelling, montmorillonite , nontronite, smectite, water, DLVO theory, surface charge, dissolution, methods, aluminum, silicon, inert atmosphere. 2G...that many physical properties of bulk water are changed when it is adsorbed between layers of Na4- montmorillonite (e.g., Oster and Low, 1964; Kolaian...Na+- montmorillonite accounted for about 13% of the total water content in the free-swelling state. We can therefore express the total water content

  17. Labial swelling: a rare presentation of pubic bone tuberculosis.

    PubMed

    Shende, Prajakta; Gandhewar, Manisha; Gaikwad, Pradip; Nanaware, Sandip; Risbud Joshi, Prachi

    2016-09-14

    Tuberculosis (TB), being a global health problem, represents variedly. Its presentation as a labial swelling secondary to pubic bone TB has been reported rarely in literature. We report a case of pubic bone TB presenting as a labial swelling in a woman of reproductive age. Early diagnosis with fine needle aspiration cytology, acid-fast bacillus (AFB) staining, AFB culture and magnetic resonance imaging with early initiation of treatment resulted in a favourable outcome.

  18. The Mouse Murr1 Gene Is Imprinted in the Adult Brain, Presumably Due to Transcriptional Interference by the Antisense-Oriented U2af1-rs1 Gene

    PubMed Central

    Wang, Youdong; Joh, Keiichiro; Masuko, Sadahiko; Yatsuki, Hitomi; Soejima, Hidenobu; Nabetani, Akira; Beechey, Colin V.; Okinami, Satoshi; Mukai, Tsunehiro

    2004-01-01

    The mouse Murr1 gene contains an imprinted gene, U2af1-rs1, in its first intron. U2af1-rs1 shows paternal allele-specific expression and is transcribed in the direction opposite to that of the Murr1 gene. In contrast to a previous report of biallelic expression of Murr1 in neonatal mice, we have found that the maternal allele is expressed predominantly in the adult brain and also preferentially in other adult tissues. This maternal-predominant expression is not observed in embryonic and neonatal brains. In situ hybridization experiments that used the adult brain indicated that Murr1 gene was maternally expressed in neuronal cells in all regions of the brain. We analyzed the developmental change in the expression levels of both Murr1 and U2af1-rs1 in the brain and liver, and we propose that the maternal-predominant expression of Murr1 results from transcriptional interference of the gene by U2af1-rs1 through the Murr1 promoter region. PMID:14673161

  19. A brief review of cavity swelling and hardening in irradiated copper and copper alloys

    SciTech Connect

    Zinkle, S.J.

    1990-01-01

    The literature on radiation-induced swelling and hardening in copper and its alloy is reviewed. Void formation does not occur during irradiation of copper unless suitable impurity atoms such as oxygen or helium are present. Void formation occurs for neutron irradiation temperatures of 180 to 550{degree}C, with peak swelling occurring at {approximately}320{degree}C for irradiation at a damage rate of 2 {times} 10{sup {minus}7} dpa/s. The post-transient swelling rate has been measured to be {approximately}0.5%/dpa at temperatures near 400{degree}C. Dispersion-strengthened copper has been found to be very resistant to void swelling due to the high sink density associated with the dispersion-stabilized dislocation structure. Irradiation of copper at temperatures below 400{degree}C generally causes an increase in strength due to the formation of defect clusters which inhibit dislocation motion. The radiation hardening can be adequately described by Seeger's dispersed barrier model, with a barrier strength for small defect clusters of {alpha} {approx} 0.2. The radiation hardening apparently saturates for fluences greater than {approximately}10{sup 24} n/m{sup 2} during irradiation at room temperature due to a saturation of the defect cluster density. Grain boundaries can modify the hardening behavior by blocking the transmission of dislocation slip bands, leading to a radiation- modified Hall-Petch relation between yield strength and grain size. Radiation-enhanced recrystallization can lead to softening of cold-worked copper alloys at temperatures above 300{degree}C.

  20. Field-Based Mantle Rheometry over the Hawaiian Swell

    NASA Astrophysics Data System (ADS)

    Ribe, N. M.; Asaadi, N.; Sobouti, F.

    2011-12-01

    Depending on their physical and chemical conditions, mantle rocks can deform either by diffusion creep (with a linear relationship between strain rate ˙ {ɛ } and stress &sigma) or by nonlinear dislocation creep. However, reliable maps showing where in the mantle each of these mechanisms is dominant are difficult to construct, primarily because standard geodynamical, seismological, and mineral physics methods for inferring mantle rheology are indirect. It is therefore desirable to identify regions where the operative deformation mechanism can be inferred directly from surface geophysical observations alone. We suggest that one such region is the uppermost mantle beneath the Hawaiian swell. We identify a new observable quantity, the rate of downstream decay of the swell topography, that depends only on the value of the exponent n in the rheological law ˙ {ɛ }∝σ n of the low-density material compensating the swell. Fluid-mechanical models for the lateral spreading of that material show that the swell topography decays as the downstream distance to the power -1/(3n + 2), indicating that the decay rate is a sensitive rheological probe. Quantitative comparison of the observed swell topography with the model predictions shows that the swell's shape is poorly explained by diffusion creep, and requires a dislocation creep rheology. The rheology inferred from the comparison is reasonably compatible with laboratory deformation data for both olivine and clinopyroxene.

  1. Rate dependence of swelling in lithium-ion cells

    SciTech Connect

    Oh, KY; Siegel, JB; Secondo, L; Kim, SU; Samad, NA; Qin, JW; Anderson, D; Garikipati, K; Knobloch, A; Epureanu, BI; Monroe, CW; Stefanopoulou, A

    2014-12-01

    Swelling of a commercial 5 Ah lithium-ion cell with a nickel/manganese/cobalt-oxide cathode is investigated as a function of the charge state and the charge/discharge rate. In combination with sensitive displacement measurements, knowledge of the electrode configuration within this prismatic cell's interior allows macroscopic deformations of the casing to be correlated to electrochemical and mechanical transformations in individual anode/separator/cathode layers. Thermal expansion and interior charge state are both found to cause significant swelling. At low rates, where thermal expansion is negligible, the electrode sandwich dilates by as much as 1.5% as the charge state swings from 0% to 100% because of lithium-ion intercalation. At high rates a comparably large residual swelling was observed at the end of discharge. Thermal expansion caused by joule heating at high discharge rate results in battery swelling. The changes in displacement with respect to capacity at low rate correlate well with the potential changes known to accompany phase transitions in the electrode materials. Although the potential response changes minimally with the C-rate, the extent of swelling varies significantly, suggesting that measurements of swelling may provide a sensitive gauge for characterizing dynamic operating states. (C) 2014 Elsevier B.V. All rights reserved.

  2. Cytotoxic edema: mechanisms of pathological cell swelling

    PubMed Central

    Liang, Danny; Bhatta, Sergei; Gerzanich, Volodymyr; Simard, J. Marc

    2009-01-01

    Cerebral edema is caused by a variety of pathological conditions that affect the brain. It is associated with two separate pathophysiological processes with distinct molecular and physiological antecedents: those related to cytotoxic (cellular) edema of neurons and astrocytes, and those related to transcapillary flux of Na+ and other ions, water, and serum macromolecules. In this review, the authors focus exclusively on the first of these two processes. Cytotoxic edema results from unchecked or uncompensated influx of cations, mainly Na+, through cation channels. The authors review the different cation channels that have been implicated in the formation of cytotoxic edema of astrocytes and neurons in different pathological states. A better understanding of these molecular mechanisms holds the promise of improved treatments of cerebral edema and of the secondary injury produced by this pathological process. PMID:17613233

  3. [Successful treatment for disseminated intra-vascular coagulation due to sepsis and brain abscess with low molecular weight heparin in a patient with antiphospholipid syndrome].

    PubMed

    Hiroishi, K; Shigenobu, Y; Asai, M; Tsuzuki, Y; Hayashi, N; Tominaga, K; Matsui, K; Hada, T; Higashino, K

    1999-02-01

    The management of disseminated intravascular coagulation (DIC) in a 22-year-old female patient with antiphospholipid syndrome is reported. Gabexate mesilate was given by continuous drip infusion at 1.5 g/day. No effect was seen, therefore Dalteparin sodium (DS) was administered by continuous drip infusion at 70 U/kg/day. The DIC score improved gradually during the first 4 days to normalization by 10 days. However, convulsive seizure was developed. Computed tomographic scan of brain demonstrated brain abscess at lt-basal ganglia. Continuous drainage was performed while administered continuous drip infusion of DS. Follow-up CT after operation showed reduction of low density area which means brain abscess. Finding in this case suggest that DS may play a role in the management of DIC accompanying intracranial infection.

  4. Enhanced resistance of CXCR3 deficient mice to ocular HSV-1 infection is due to control of replication in the brain ependyma.

    PubMed

    Kroll, Chandra M; Zheng, Min; Carr, Daniel J J

    2014-11-15

    CXCR3 deficient (CXCR3(-/-)) mice are resistant to ocular HSV-1 infection in that less mice develop encephalitis and succumb to infection in comparison to wild type (WT) animals. A region of the brain previously identified to be crucial for development of encephalitis was evaluated in HSV-1-infected CXCR3(-/-) and WT mice. In this region, known as the ependyma, viral titer, infiltrating leukocyte populations, and key anti-viral cytokine message levels were evaluated. We found that CXCR3(-/-) mice possessed significantly less HSV-1 and expressed significantly more IFN-β mRNA in the brain ependyma compared to WT animals during the development of encephalitis.

  5. Influence of swelling on water transport through PVA-based membrane

    NASA Astrophysics Data System (ADS)

    Praptowidodo, Veronica S.

    2005-04-01

    Dehydration of ethanol is studied using various PVA-based membranes. Due to its high solubility in water, PVA membrane has a great extent of swelling in ethanol-water mixture, resulting in a remarkable decline of selectivity. To restrict the extent of swelling, PVA membranes were chemically modified by crosslinking reaction by glutaraldehyde. Crosslinking reaction was conducted by using two concentrations of glutaraldehyde, i.e. 0.025 and 0.100% by weight, and the degree of crosslinking was varied by changing the reaction time. The difference degree of crosslinking was examined by the extent of swelling. Those modified membranes were performed by pervaporation to study the effect of crosslinking on separation process. Crosslinked PVA-membrane with 26.5% swelling degree, produced flux 0.28 kg/m 2 h, and separation factor 104 at the condition of pervaporation at 40 °C and 0.4 mbar downstream pressure, using feed solution 90 wt% of ethanol. The present of charged groups in PVA-N and PVA-It membranes decrease the swelling degree to 15.65 and 14.00%, respectively. At feed concentration of ethanol 96% by pervaporation, PVA membrane with swelling degree 26.5%, produced flux, J=0.279 kg/m 2 h and separation factor, α=107; PVA-N membrane flux, J=0.123 kg/m 2 h and separation factor, α=216; PVA-It membrane flux, J=0.119 kg/m 2 h and separation factor, α=228. The present of charged groups increase selectivity, however it decrease flux. By decreasing down stream pressure from 0.4 to 0.14 mbar at the same pervaporation condition, the membrane selectivity changed to a higher values, PVA membrane flux, J=0.189 kg/m 2 h and separation factor, α=335; PVA-N membranes flux, J=0.089 kg/m 2 h and separation factor α=709; PVA-It membranes flux, J=0.086 kg/m 2 h and separation factor α=837. The presence of charged groups in polymers and the down stream pressure influence potentially to improve membrane selectivity. Substitution of anionic and cationic charged groups to PVA

  6. Competition between adsorption-induced swelling and elastic compression of coal at CO2 pressures up to 100 MPa

    NASA Astrophysics Data System (ADS)

    Hol, Sander; Spiers, Christopher J.

    2012-11-01

    Enhanced Coalbed Methane production (ECBM) by CO2 injection frequently proves ineffective due to rapidly decreasing injectivity. Adsorption-induced swelling of the coal matrix has been identified as the principal factor controlling this reduction. To improve understanding of coal swelling in response to exposure to CO2 at high pressures, numerous laboratory studies have been performed in the past decades. These studies consistently reveal an increase in swelling with CO2 pressure. However, it remains unclear what the relative contributions are of adsorption-induced swelling versus elastic compression of the coal framework, and hence what is the true relationship between adsorption-induced swelling and CO2 uptake. Here, we report the results of dilatometry experiments conducted on unconfined, cylindrical coal matrix samples (˜4 mm long and 4 mm in diameter) of high volatile bituminous coal, where we aim to measure the effective volumetric effect of CO2 and to separate this into a component caused by adsorption-induced swelling and a component caused by elastic compression. The experiments were performed using a high pressure eddy current dilatometer that was used to measure one-dimensional sample expansion or contraction (resolution <50 nm). The tests were conducted at a constant temperature of 40 °C, and CO2 pressures up to 100 MPa. Our results show that the matrix samples reveal anisotropic expansion over the full range of CO2 pressures used. Expansion perpendicular to the bedding was about 1.4 times the average expansion measured in the bedding plane. Net volumetric strains, which were computed from the net linear strain in all directions measured, reveal that the response of coal is characterised by an expansion-dominated stage below 10-20 MPa of CO2 pressure and a contraction-dominated stage at higher CO2 pressures. Our data demonstrate direct competition between adsorption-induced swelling and elastic compression in the coal matrix. We propose a model for

  7. The Goodman swell: a lithospheric flexure caused by crustal loading along the Midcontinent rift system

    USGS Publications Warehouse

    Peterman, Z.E.; Sims, P.K.

    1988-01-01

    Rb-Sr biotite ages of Archean and Early to Middle Proterozoic crystalline rocks in northern Wisconsin and adjacent Upper Peninsula of Michigan describe a regionally systematic pattern related to differential uplift. An "age low' occurs in northern Wisconsin where values range from 1070-1172 Ma for rocks with crystallization ages of 1760 to 1865 Ma. These values overlap with the main episode of mafic igneous activity (1090 to 1120 Ma) along the Midcontinent rift system (MRS). We interpret these low biotite ages as registering closure due to cooling below the 300??C isotherm as a consequence of uplift and rapid erosion of an area that we are informally naming the Goodman swell. We interpret the swell to be a forebulge imposed on an elastic crust by loading of mafic igneous rocks along and within the axis of the MRS. -from Authors

  8. The hypo-osmotic swelling test for evaluation of sperm membrane integrity.

    PubMed

    Ramu, Sivakumar; Jeyendran, Rajasingam S

    2013-01-01

    A functional membrane is requisite for the fertilizing ability of spermatozoa, as it plays an integral role in sperm capacitation, acrosome reaction, and binding of the spermatozoon to the egg surface. The hypo-osmotic swelling (HOS) test evaluates the functional integrity of the sperm's plasma membrane and also serves as a useful indicator of fertility potential of sperm. The HOS test predicts membrane integrity by determining the ability of the sperm membrane to maintain equilibrium between the sperm cell and its environment. Influx of the fluid due to hypo-osmotic stress causes the sperm tail to coil and balloon or "swell." A higher percentage of swollen sperm indicates the presence of sperm having a functional and intact plasma membrane. Here, we present the detailed protocol for performing the HOS test and explain the results for interpretation.

  9. Unusual swelling of HPC in toluene forming a microspherical domain structure that causes Christiansen scattering coloration.

    PubMed

    Edo, Susumu; Okoshi, Kento; Kang, Sungmin; Tokita, Masatoshi; Kaneko, Tatsuo; Watanabe, Junji

    2010-02-02

    The unusual swelling behavior of hydroxypropyl cellulose (HPC) by toluene is described. At temperatures as high as 100 degrees C, toluene molecules can enter the HPC film up to the weight fraction of 55%; however, they are segregated from the HPC matrix and form microspherical domains. The size of the spherical domain is approximately 4.5 microm in diameter on average. Such an unusual swelling behavior is due to the amphiphilic nature of the HPC; HPC polymers rearrange to contact their hydrophobic group with toluene and confine the toluene molecules in spherical domains. Because of the similarity in refractive indices of the toluene microspherical phase and the HPC continuum phase, the swollen film shows a beautiful scattering color that is called the Christiansen filter effect.

  10. Swellings over the Limbs as the Earliest Feature in a Patient with Osteogenesis Imperfecta Type V

    PubMed Central

    Ganger, Rudolf; Klaushofer, Klaus; Grill, Franz

    2014-01-01

    Swellings over the upper and lower limbs were encountered in a one-year-old child. Skeletal survey showed a constellation of distinctive radiographic abnormalities of osteoporosis, hyperplastic callus and ossification of the interosseous membrane of the forearm, femora, and to lesser extent the tibiae. Neither wormian bones of the skull nor dentinogenesis imperfecta was present. Genetic tests revealed absence of mutation in COL1A1 or COL1A2 genes, respectively. The overall phenotypic features were consistent with the diagnosis of osteogenesis imperfecta type V (OI-V). The aim of this paper is to distinguish between swellings because of intrinsic bone disorders and these due to child physical abuse. PMID:24772361

  11. Pharmacokinetics of amantadine in children with impaired consciousness due to acquired brain injury: preliminary findings using a sparse-sampling technique.

    PubMed

    Vargus-Adams, Jilda N; McMahon, Mary A; Michaud, Linda J; Bean, Judy; Vinks, Alexander A

    2010-01-01

    To evaluate the pharmacokinetics of amantadine in children with impaired consciousness from acquired brain injury. Randomized, double-blind, placebo-controlled, crossover study with sparse sampling for pharmacokinetics. Tertiary care pediatric hospital. Children, ages 6-18 years, with impaired consciousness 5-10 weeks after acquired brain injury. Subjects received amantadine for 3 weeks. Subjects were randomized to placebo or amantadine 4 mg/kg/day for 7 days followed by 6 mg/kg/day for 14 days. Crossover was after a 7-day washout period. The Coma/Near-Coma Scale and Coma Recovery Scale-Revised were done 3 times per week to evaluate arousal and consciousness. Plasma concentrations of amantadine were determined for pharmacokinetic parameter estimation and evaluation of the exposure-response relationship. Adverse events were monitored. Nine subjects met the final inclusion and exclusion criteria, 7 of whom agreed to participate. Five subjects completed both arms of the study. Amantadine total body clearance was 0.17 L/h/kg with a half-life of 13.9 hours. Higher exposure of amantadine (average concentration of amantadine during 6 mg/kg/day > 1.5 mg/L) may be associated with better recovery of consciousness. Amantadine was well-tolerated in children with acquired brain injury and demonstrates pharmacokinetics similar to those reported for healthy young adults. Based on the preliminary data, higher dosing may be considered in the setting of brain injury.

  12. Coupled thermo-hydro-chemical models of swelling bentonites

    NASA Astrophysics Data System (ADS)

    Samper, Javier; Mon, Alba; Zheng, Liange; Montenegro, Luis; Naves, Acacia; Pisani, Bruno

    2014-05-01

    The disposal of radioactive waste in deep geological repositories is based on the multibarrier concept of retention of the waste by a combination of engineered and geological barriers. The engineered barrier system (EBS) includes the solid conditioned waste-form, the waste container, the buffer made of materials such as clay, grout or crushed rock that separate the waste package from the host rock and the tunnel linings and supports. The geological barrier supports the engineered system and provides stability over the long term during which time radioactive decay reduces the levels of radioactivity. The strong interplays among thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes during the hydration, thermal and solute transport stages of the engineered barrier system (EBS) of a radioactive waste repository call for coupled THMC models for the metallic overpack, the unsaturated compacted bentonite and the concrete liner. Conceptual and numerical coupled THMC models of the EBS have been developed, which have been implemented in INVERSE-FADES-CORE. Chemical reactions are coupled to the hydrodynamic processes through chemical osmosis (C-H coupling) while bentonite swelling affects solute transport via changes in bentonite porosity changes (M-H coupling). Here we present THMC models of heating and hydration laboratory experiments performed by CIEMAT (Madrid, Spain) on compacted FEBEX bentonite and numerical models for the long-term evolution of the EBS for 1 Ma. The changes in porosity caused by swelling are more important than those produced by the chemical reactions during the early evolution of the EBS (t < 100 years). For longer times, however, the changes in porosity induced by the dissolution/precipitation reactions are more relevant due to: 1) The effect of iron mineral phases (corrosion products) released by the corrosion of the carbon steel canister; and 2) The hyper alkaline plume produced by the concrete liner. Numerical results show that

  13. What can asymmetry tell us? Investigation of asymmetric versus symmetric pinch and swell structures in nature and simulation

    NASA Astrophysics Data System (ADS)

    Gardner, Robyn; Piazolo, Sandra; Daczko, Nathan

    2015-04-01

    Pinch and swell structures occur from microscopic to landscape scales where a more competent layer in a weaker matrix is deformed by pure shear, often in rifting environments. The Anita Shear Zone (ASZ) in Fiordland, New Zealand has an example of landscape scale (1 km width) asymmetric pinch and swell structures developed in ultramafic rocks. Field work suggests that the asymmetry is a result of variations in the surrounding 'matrix' flow properties as the ultramafic band is surrounded to the east by an orthogneiss (Milford Orthogneiss) and to the west by a paragneiss (Thurso Paragneiss). In addition, there is a narrow and a much wider shear zone between the ultramafics and the orthogneiss and paragneiss, respectively. Detailed EBSD analysis of samples from a traverse across the pinch and swell structure indicate the ultramafics in the shear zone on the orthogneiss side have larger grain size than the ultramafics in the shear zone on the paragneiss side. Ultramafic samples from the highly strained paragneiss and orthogneiss shear zones show dislocation creep behaviour, and, on the paragneiss side, also significant deformation by grain boundary sliding. To test if asymmetry of pinch and swell structures can be used to derive the rheological properties of not only the pinch and swell lithologies, but also of the matrix, numerical simulations were performed. Numerical modelling of pure shear (extension) was undertaken with (I) initially three layers and then (II) five layers by adding soft high strain zones on both sides of the rheological hard layer. The matrix was given first symmetric, then asymmetric viscosity. Matrix viscosity was found to impact the formation of pinch and swell structures with the weaker layer causing increased tortuosity of the competent layer edge due to increased local differential stress. Results highlight that local, rheologically soft layers and the relative viscosity of matrix both impact significantly the shape and symmetry of developing

  14. ICG-assisted blood vessel detection during stereotactic neurosurgery: simulation study on excitation power limitations due to thermal effects in human brain tissue.

    PubMed

    Rühm, Adrian; Göbel, Werner; Sroka, Ronald; Stepp, Herbert

    2014-09-01

    Intraoperative blood vessel detection based on intraluminal indocyanin-green (ICG) would allow to minimize the risk of blood vessel perforation during stereotactic brain tumor biopsy. For a fiber-based approach compatible with clinical conditions, the maximum tolerable excitation light power was derived from simulations of the thermal heat load on the tissue. Using the simulation software LITCIT, the temperature distribution in human brain tissue was calculated as a function of time for realistic single-fiber probes (0.72mm active diameter, numerical aperture 0.35, optional focusing to 0.29mm diameter) and for the optimum ICG excitation wavelength of 785nm. The asymptotic maximum temperature in the simulated tissue region was derived for different radiant fluxes at the distal fiber end. Worst case values were assumed for all other parameters. In addition to homogeneous (normal and tumor) brain tissue with homogeneous blood perfusion, models with localized extra blood vessels incorporated ahead of the distal fiber end were investigated. If one demands that destruction of normal brain tissue must be excluded by limiting the tissue heating to 42°C, then the radiant flux at the distal fiber end must be limited to 33mW with and 43mW without focusing. When considering extra blood vessels of 0.1mm diameter incorporated into homogeneously perfused brain tissue, the tolerable radiant flux is reduced to 22mW with and 32mW without focusing. The threshold value according to legal laser safety regulations for human skin tissue is 28.5mW. For the envisaged modality of blood vessel detection, light power limits for an application-relevant fiber configuration were determined and found to be roughly consistent with present legal regulations for skin tissue. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. The impact of silicone hydrogel materials on overnight corneal swelling.

    PubMed

    Steffen, Robert B; Schnider, Cristina M

    2007-05-01

    To identify the corneal swelling response associated with silicone hydrogel contact lens wear. Twenty-five subjects were recruited to participate in this single-center, controlled, single-masked, clinical trial. The corneal swelling response was evaluated by central corneal pachymetry after overnight wear of balafilcon A, etafilcon A, lotrafilcon A, senofilcon A, and no lens wear. More specifically, after 8 hours of closed-eye wear of each material, corneal thickness was measured immediately on eye opening, in addition to the first 4 hours of open-eye wear. Paired t tests were used to compare the swelling response from each condition to that associated with senofilcon A, and given the numerous statistical comparisons, a P value of swelling response when comparing balafilcon A (1.35%), lotrafilcon A (1.22%), or no lens wear (0.77%) to senofilcon A (1.40%), although the swelling response associated with etafilcon A was significantly greater (P<0.001) than that associated with senofilcon A. There were no differences between balafilcon A, lotrafilcon A, and no lens wear compared to senofilcon A during the open-eye deswelling period. However, 1 hour after eye opening, corneal swelling remained significantly greater with etafilcon A than with senofilcon A (1.76% vs. -0.51%, respectively, P=0.01), although no other time-specific comparisons differed. Silicone hydrogel lenses, with high oxygen transmissibilities, are associated with very little corneal swelling after overnight wear of the lenses.

  16. Measuring and partitioning soil respiration in sharkey shrink-swell clays under plantation grown short-rotation woody crops

    Treesearch

    Wilson G. Hood; Michael C. Tyree; Dylan N. Dillaway Dillaway; Theodor D. Leininger

    2015-01-01

    The Lower Mississippi Alluvial Valley (LMAV) offers an ecological niche for short-rotation woody crop (SRWC) production by mating marginal agricultural land with optimal growing conditions. Approximately 1.7 million ha within the LMAV consist of Sharkey shrink-swell clays. They are considered marginal in terms of traditional agricultural productivity due to their...

  17. In-Situ NDT Measurements of Irradiation Induced Swelling in PWR Core Internal Components - Phase 2: Testing of Irradiated Materials

    SciTech Connect

    I.Balachov, F.Garner, Y. Isobe

    2004-04-01

    OAK-B135 The objective of the project is to examine and develop in-situ nondestructive testing (NDT) techniques for measuring irradiation induced swelling in the internal components of PWRs. the two phases scope of the project covers development, validation, and application of NDT sensors capable of locating and measuring hidden volume expansion due to swelling at levels 0.1-0.5% or larger based on indirect material property variations such as Young's modulus changes. The first phase study published previously focused on evaluation NDT techniques using unirradiated surrogate materials. This report documents the second phase effort on benchmarking NDT techniques by testing irradiated materials.

  18. Evaluating the Swelling, Erosion and Compaction Properties of Cellulose Ethers.

    PubMed

    Ghori, Muhammad U; Grover, Liam M; Asare-Addo, Kofi; Smith, Alan M; Conway, Barbara R

    2017-10-06

    Swelling, erosion, deformation and consolidation properties can affect the performance of cellulose ethers, the most commonly used matrix former in hydrophilic sustained tablet formulations. The present study was designed to comparatively evaluate the swelling, erosion, compression, compaction and relaxation properties of the cellulose ethers in a comprehensive study using standardised conditions. The interrelationship between various compressional models and the inherent deformation and consolidation properties of the polymers on the derived swelling and erosion parameters are consolidated. The impact of swelling (Kw) on erosion rates (KE) and the inter-relationship between Heckel and Kawakita plasticity constants was also investigated. It is evident from the findings that the increases in both substitution and polymer chain length led to higher Kw, but a lower KE; this was also true for all particle size fractions regardless of polymer grade. Smaller particle size and high substitution levels tend to increase the relative density of the matrix but reduce porosity, yield pressure (Py), Kawakita plasticity parameter (b(-1)) and elastic relaxation. Both KW vs KE (R(2) = 0.949-0.980) and Py vs b(-1) correlations (R(2) = 0.820-0.934) were reasonably linear with regards to increasing hydroxypropyl substitution and molecular size. Hence, it can be concluded that the combined knowledge of swelling and erosion kinetics in tandem with the in and out-of-die compression findings can be used to select a specific polymer grade and further to develop and optimise formulations for oral controlled drug delivery applications.

  19. Dynamics of Swelling and Drying in a Spherical Gel

    NASA Astrophysics Data System (ADS)

    Bertrand, Thibault; Peixinho, Jorge; Mukhopadhyay, Shomeek; MacMinn, Christopher W.

    2016-12-01

    Swelling is a volumetric-growth process in which a porous material expands by spontaneous imbibition of additional pore fluid. Swelling is distinct from other growth processes in that it is inherently poromechanical: local expansion of the pore structure requires that additional fluid be drawn from elsewhere in the material, or into the material from across the boundaries. Here, we study the swelling and subsequent drying of a sphere of hydrogel. We develop a dynamic model based on large-deformation poromechanics and the theory of ideal elastomeric gels, and we compare the predictions of this model with a series of experiments performed with polyacrylamide spheres. We use the model and the experiments to study the complex internal dynamics of swelling and drying, and to highlight the fundamentally transient nature of these strikingly different processes. Although we assume spherical symmetry, the model also provides insight into the transient patterns that form and then vanish during swelling as well as the risk of fracture during drying.

  20. Void swelling and microstructure evolution at very high damage level in self-ion irradiated ferritic-martensitic steels

    NASA Astrophysics Data System (ADS)

    Getto, E.; Sun, K.; Monterrosa, A. M.; Jiao, Z.; Hackett, M. J.; Was, G. S.

    2016-11-01

    The void swelling and microstructure evolution of ferritic-martensitic alloys HT9, T91 and T92 were characterized following irradiation with Fe++ ions at 460 °C to damage levels of 75-650 displacements per atom with 10 atom parts per million pre-implanted helium. Steady state swelling rate of 0.033%/ dpa was determined for HT9, the least swelling resistant alloy, and 0.007%/ dpa in T91. In T91, resistance was due to suppression of void nucleation. Swelling resistance was greatest in T92, with a low density (∼1 × 1020 m-3) of small voids that had not grown appreciably, indicating suppression of nucleation and growth. Additional heats of T91 indicated that alloy composition was not the determining factor of swelling resistance. Carbon and chromium-rich M2X precipitates formed at 250 dpa and were correlated with decreased nucleation in T91 and T92, but did not affect void growth in HT9. Dislocation and G-phase microstructure evolution was analyzed up to 650 dpa in HT9.

  1. Impact of salt form and molecular weight of chitosan on swelling and drug release from chitosan matrix tablets.

    PubMed

    Huanbutta, Kampanart; Cheewatanakornkool, Kamonrak; Terada, Katsuhide; Nunthanid, Jurairat; Sriamornsak, Pornsak

    2013-08-14

    Magnetic resonance imaging (MRI) and gravimetric techniques were used to assess swelling and erosion behaviors of hydrophilic matrix tablets made of chitosan. The impact of salt form, molecular weight (MW) and dissolution medium on swelling behavior and drug (theophylline) release was studied. The matrix tablets made of chitosan glycolate (CGY) showed the greatest swelling in both acid and neutral media, compared to chitosan aspartate, chitosan glutamate and chitosan lactate. MRI illustrated that swelling region of CGY in both media was not different in the first 100 min but glassy region (dry core) in 0.1N HCl was less than in pH 6.8 buffer. The tablets prepared from chitosan with high MW swelled greater than those of low MW. Moreover, CGY can delay drug release in the acid condition due to thick swollen gel and low erosion rate. Therefore, CGY may be suitably applied as sustained drug release polymer or enteric coating material. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Opening of the blood-brain barrier tight junction due to shock wave induced bubble collapse: a molecular dynamics simulation study.

    PubMed

    Goliaei, Ardeshir; Adhikari, Upendra; Berkowitz, Max L

    2015-08-19

    Passage of a shock wave across living organisms may produce bubbles in the blood vessels and capillaries. It was suggested that collapse of these bubbles imposed by an impinging shock wave can be responsible for the damage or even destruction of the blood-brain barrier. To check this possibility, we performed molecular dynamics computer simulations on systems that contained a model of tight junction from the blood-brain barrier. In our model, we represent the tight junction by two pairs of interacting proteins, claudin-15. Some of the simulations were done in the absence of a nanobubble, some in its presence. Our simulations show that when no bubble is present in the system, no damage to tight junction is observed when the shock wave propagates across it. In the presence of a nanobubble, even when the impulse of the shock wave is relatively low, the implosion of the bubble causes serious damage to our model tight junction.

  3. Swelling-induced Ca2+ release from intracellular calcium stores in rat submandibular gland acinar cells.

    PubMed

    Park, K; Lee, S; Elliott, A C; Kim, J S; Lee, J H

    2002-04-01

    The effects of osmotically-induced cell swelling on cytoplasmic free Ca2+ concentration ([Ca2+]i) were studied in acinar cells from rat submandibular gland using microspectrofluorimetry. Video-imaging techniques were also used to measure cell volume. Hypotonic stress (78% control tonicity) caused rapid cell swelling reaching a maximum relative volume of 1.78 +/- 0.05 (n = 5) compared to control. This swelling was followed by regulatory volume decrease, since relative cell volume decreased significantly to 1.61 +/- 0.08 (n = 5) after 10 min exposure to hypotonic medium. Osmotically induced cell swelling evoked by medium of either 78% or 66% tonicity caused a biphasic increase of [Ca2+]i. The rapid phase of this increase in [Ca2+]i was due to release of Ca2 + from intracellular stores, since it was also observed in cells bathed in Ca2+-free solution. The peak increase of [Ca2+]i induced by cell swelling was 3.40 +/- 0.49 (Fura-2 F340/F380 fluorescence ratio, n = 11) and 3.17 +/- 0.43 (n = 17) in the presence and the absence of extracellular Ca2+, respectively, corresponding to an absolute [Ca2+]i of around 1 microm. We found that around two-thirds of cells tested still showed some swelling-induced Ca2+ release (SICR) even after maximal concentrations (10(-5) M - 10(-4) M) of carbachol had been applied to empty agonist-sensitive intracellular Ca2+ stores. This result was confirmed and extended using thapsigargin to deplete intracellular Ca2+ pools. Hypotonic shock still raised [Ca2+]i in cells pretreated with thapsigargin, confirming that at least some SICR occurred from agonist-insensitive stores. Furthermore, SICR was largely inhibited by pretreatment of cells with carbonyl cyanide m-cholorophenyl hydrazone (CCCP) or ruthenium red, inhibitors of mitochondrial Ca2+ uptake. Our results suggest that the increase in [Ca2+]i, which underlies regulatory volume decrease in submandibular acinar cells, results from release of Ca2+ from both agonist-sensitive and

  4. Rapid Eye Movement Sleep Deprivation Associated Increase in Na-K ATPase Activity in the Rat Brain is Due to Noradrenaline Induced α1-Adrenoceptor Mediated Increased α-Subunit of the Enzyme.

    PubMed

    Amar, Megha; Mallick, Birendra Nath

    2015-08-01

    Rapid eye movement sleep (REMS) modulates Na-K ATPase activity and maintains brain excitability. REMS deprivation (REMSD)-associated increased Na-K ATPase activity is mediated by noradrenaline (NA) acting on α1-adrenoceptor (AR) in the brain. It was shown that NA-induced increased Na-K ATPase activity was due to allosteric modulation as well as increased turnover of the enzyme. Although the former has been studied in detail, our understanding on the latter was lacking, which we have studied. Male Wistar rats were REMS deprived for 4-days by classical flower-pot method; suitable control experiments were conducted. In another set, α1-AR antagonist prazosin (PRZ) was i.p. injected 48 h REMSD onward. At the end of experiments rats were sacrificed by cervical dislocation and brains were removed. Synaptosomes prepared from the brains were used to estimate Na-K ATPase activity as well as protein expressions of different isoforms of the enzyme subunits using western blot. REMSD significantly increased synaptosomal Na-K ATPase activity and that was due to differential increase in the expressions of α1-, α2- and α3-isoforms, but not that of β1- and β2-isoforms. PRZ reduced the REMSD-induced increased Na-K ATPase activity and protein expressions. We also observed that the increased Na-K ATPase subunit expression was not due to enhanced mRNA synthesis, which suggests the possibility of post-transcriptional regulation. Thus, the findings suggest that REMSD-associated increased Na-K ATPase activity is due to elevated level of α-subunit of the enzyme and that is induced by NA acting on α1-AR mediated mRNA-stabilization.

  5. Non-invasive analysis of swelling in polymer dispersions by means of time-domain(TD)-NMR.

    PubMed

    Nestle, Nikolaus; Häberle, Karl

    2009-11-03

    In this contribution, we discuss the potential of low-field time-domain(TD)-NMR to study the swelling of (aqueous) polymer dispersions by a volatile solvent. Due to the sensitivity of transverse relaxation times (T2) to swelling-induced changes in the molecular dynamics of the polymer component, the effects of swelling can be measured without spectral resolution. The measurement is performed on polymer dispersions in native state with solids contents around 50% in a non-invasive way without separating the polymeric phase and the water phase from each other. Using acetone in two polyurethane (PU) dispersions with different hard phase contents, we explore the sensitivity of the method and present a data evaluation strategy based on multicomponent fitting and proton balancing. Furthermore, we report exchange continualization as a further effect that needs to be taken into account for correct interpretation of the data.

  6. Partial trisomy due to a de novo duplication 22q11.1-22q13.1: a cat-eye syndrome variant with brain anomalies.

    PubMed

    Karcaaltincaba, D; Ceylaner, S; Ceylaner, G; Dalkilic, S; Karli-Oguz, K; Kandemir, O

    2010-01-01

    We report a case of partial trisomy 22q with de novo duplication of chromosomal region 22q11.1-22q13.1, also confirmed by microarray comparative genomic hybridization (Array-CGH) analysis. The fetus had interhemispheric cyst and corpus callosum agenesis diagnosed by MRI which has not been reported in the literature. This novel phenotype differs from the reported cat eye syndromes by the absence of heart defects and the presence of brain anomalies.

  7. The MDS-UPDRS tracks motor and non-motor improvement due to subthalamic nucleus deep brain stimulation in Parkinson disease.

    PubMed

    Chou, Kelvin L; Taylor, Jennifer L; Patil, Parag G

    2013-11-01

    The Movement Disorders Society revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS) improves upon the original UPDRS by adding more non-motor items, making it a more robust tool to evaluate the severity of motor and non-motor symptoms of Parkinson disease. Previous studies on deep brain stimulation have not used the MDS-UPDRS. To determine if the MDS-UPDRS could detect improvement in both motor and non-motor symptoms after bilateral subthalamic nucleus deep brain stimulation for Parkinson disease. We compared scores on the entire MDS-UPDRS prior to surgery (baseline) and approximately six months following the initial programming visit in twenty subjects (12M/8F) with Parkinson disease undergoing bilateral subthalamic nucleus deep brain stimulation. STN DBS significantly improved the scores for every section of the MDS-UPDRS at the 6 month follow-up. Part I improved by 3.1 points (22%), Part II by 5.3 points (29%), Part III by 13.1 points (29%) with stimulation alone, and Part IV by 7.1 points (74%). Individual non-motor items in Part I that improved significantly were constipation, light-headedness, and fatigue. Both motor and non-motor symptoms, as assessed by the MDS-UPDRS, improve with bilateral subthalamic nucleus stimulation six months after the stimulator is turned on. We recommend that the MDS-UPDRS be utilized in future deep brain stimulation studies because of the advantage of detecting change in non-motor symptoms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Subtle changes in myelination due to childhood experiences: label-free microscopy to infer nerve fibers morphology and myelination in brain (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Gasecka, Alicja; Tanti, Arnaud; Lutz, Pierre-Eric; Mechawar, Naguib; Cote, Daniel C.

    2017-02-01

    Adverse childhood experiences have lasting detrimental effects on mental health and are strongly associated with impaired cognition and increased risk of developing psychopathologies. Preclinical and neuroimaging studies have suggested that traumatic events during brain development can affect cerebral myelination particularly in areas and tracts implicated in mood and emotion. Although current neuroimaging techniques are quite powerful, they lack the resolution to infer myelin integrity at the cellular level. Recently demonstrated coherent Raman microscopy has accomplished cellular level imaging of myelin sheaths in the nervous system. However, a quantitative morphometric analysis of nerve fibers still remains a challenge. In particular, in brain, where fibres exhibit small diameters and varying local orientation. In this work, we developed an automated myelin identification and analysis method that is capable of providing a complete picture of axonal myelination and morphology in brain samples. This method performs three main procedures 1) detects molecular anisotropy of membrane phospholipids based on polarization resolved coherent Raman microscopy, 2) identifies regions of different molecular organization, 3) calculates morphometric features of myelinated axons (e.g. myelin thickness, g-ratio). We applied this method to monitor white matter areas from suicides adults that suffered from early live adversity and depression compared to depressed suicides adults and psychiatrically healthy controls. We demonstrate that our method allows for the rapid acquisition and automated analysis of neuronal networks morphology and myelination. This is especially useful for clinical and comparative studies, and may greatly enhance the understanding of processes underlying the neurobiological and psychopathological consequences of child abuse.

  9. Generation of continental rifts, basins, and swells by lithosphere instabilities

    NASA Astrophysics Data System (ADS)

    Fourel, LoïC.; Milelli, Laura; Jaupart, Claude; Limare, Angela

    2013-06-01

    Continents may be affected simultaneously by rifting, uplift, volcanic activity, and basin formation in several different locations, suggesting a common driving mechanism that is intrinsic to continents. We describe a new type of convective instability at the base of the lithosphere that leads to a remarkable spatial pattern at the scale of an entire continent. We carried out fluid mechanics laboratory experiments on buoyant blocks of finite size that became unstable due to cooling from above. Dynamical behavior depends on three dimensionless numbers, a Rayleigh number for the unstable block, a buoyancy number that scales the intrinsic density contrast to the thermal one, and the aspect ratio of the block. Within the block, instability develops in two different ways in an outer annulus and in an interior region. In the outer annulus, upwellings and downwellings take the form of periodically spaced radial spokes. The interior region hosts the more familiar convective pattern of polygonal cells. In geological conditions, such instabilities should manifest themselves as linear rifts striking at a right angle to the continent-ocean boundary and an array of domal uplifts, volcanic swells, and basins in the continental interior. Simple scaling laws for the dimensions and spacings of the convective structures are derived. For the subcontinental lithospheric mantle, these dimensions take values in the 500-1000 km range, close to geological examples. The large intrinsic buoyancy of Archean lithospheric roots prevents this type of instability, which explains why the widespread volcanic activity that currently affects Western Africa is confined to post-Archean domains.

  10. Reduced grey matter metabolism due to white matter edema allows optimal assessment of brain tumors on 18F-FDG-PET.

    PubMed

    Pourdehnad, Michael; Basu, Sandip; Duarte, Paulo; Okpaku, Aubrey S; Saboury, Babak; Hustinx, Roland; Alavi, Abass

    2011-01-01

    The main aim of this research was to demonstrate that the cortical and subcortical grey matter hypometabolism as revealed by fluorine-18 fluorodesoxyglucose-positron emission tomography ((18)F-FDG-PET) imaging in brain tumors is related to associated edema as demonstrated by magnetic resonance imaging (MRI). This in turn enhances the ability to assess disease activity in the tumor and the degree of loss of cerebral function in the adjacent and distant structures. We evaluated brain T1 and T2 weighted MRI and (18)F-FDG-PET scans of 29 patients (19 adult, 10 pediatric) with history of brain tumor. Tumor histology types included 21 gliomas, 1 melanoma, 1 primitive neuroectodermal tumor, 3 medulloblastomas and 3 ependymomas. The majority of scans were performed within the same week (94% <1 month. The extent of hypo and hypermetabolism was assessed on the (18)F-FDG-PET scans. A template of 12 regions of interest (ROI) was applied and the laterality indices of the regional counts (signal intensity) were computed. Extent of edema, enhancement, and anatomical change were assessed on the MRI scans. Extent of edema in the same ROI was evaluated by a 6-point semiquantitative scale and laterality indices were generated. Metabolic activity of the grey matter was correlated with the extent of edema using these indices. In all cases where edema was present, significant hypometabolism was observed in the adjacent structures. Overall, there was a strong correlation between the extent of edema and severity of hypometabolism (r=0.92, P=0.01). This was true regardless of the location of edema, whether there was history of radiation treatment (r=0.91, P=0.03), or not (r=0.97, P=0.17). In conclusion, edema independent of underlying variables appeared to contribute significantly to cortical and sub-cortical grey matter hypometabolism observed in patients with brain tumors. This would indicate that brain tumors can be successfully assessed by (18)F-FDG-PET and therefore the efforts for

  11. Facial swelling in a sickle cell patient.

    PubMed

    DeBlieux, Tyler K; Jackson, Neal; Jeyakumar, Anita; Townsend, Janice A; Naik, Bijal V

    2014-01-01

    Sickle cell disease (SCD) is characterized as a chronic hemolytic anemia with vaso-occlusive crises that result in multisystem organ damage. Bone marrow is one of the more common sites of these crises, presumably due to marrow hypercellularity that impairs blood flow- leading to regional hypoxia and subsequent infarction. Infarcts of facial bones are considered an uncommon complication of SCD. When infarcts occur in facial bones, the mandible and orbital bones are the most commonly affected. Overall, the clinical presentation of facial bone infarctions may mimic an infectious process, such as cellulitis, an abscess, or, more commonly, osteomyelitis. The purpose of this paper was to present the case of a patient with a confluence of symptoms in the face as a result of her sickle cell disease.

  12. Swelling of several commercial alloys following high fluence neutron irradiation

    NASA Astrophysics Data System (ADS)

    Powell, R. W.; Peterson, D. T.; Zimmerschied, M. K.; Bates, J. F.

    Swelling values have been determined for a set of commercial alloys irradiated to a peak fluence of 1.8 × 10 23 n/cm 2 (E >0.1 MeV) over the temperature range of 400 to 650°C. The alloys studied fall into three classes: the ferritic alloys AISI 430F, AISI 416, EM-12, H-11 and 2 {1}/{4}Cr-1Mo; the superalloys Inconel 718 and Inconel X-750; and the refractory alloys TZM and Nb-1Zr. All of these alloys display swelling resistance far superior to cold worked AISI 316. Of the three alloy classes examined the swelling resistance of the ferritics is the least sensitive to composition.

  13. Depleting depletion: Polymer swelling in poor solvent mixtures

    NASA Astrophysics Data System (ADS)

    Mukherji, Debashish; Marques, Carlos; Stuehn, Torsten; Kremer, Kurt

    A polymer collapses in a solvent when the solvent particles dislike monomers more than the repulsion between monomers. This leads to an effective attraction between monomers, also referred to as depletion induced attraction. This attraction is the key factor behind standard polymer collapse in poor solvents. Strikingly, even if a polymer exhibits poor solvent condition in two different solvents, it can also swell in mixtures of these two poor solvents. This collapse-swelling-collapse scenario is displayed by poly(methyl methacrylate) (PMMA) in aqueous alcohol. Using molecular dynamics simulations of a thermodynamically consistent generic model and theoretical arguments, we unveil the microscopic origin of this phenomenon. Our analysis suggests that a subtle interplay of the bulk solution properties and the local depletion forces reduces depletion effects, thus dictating polymer swelling in poor solvent mixtures.

  14. Swelling equilibria for temperature-sensitive ampholytic hydrogels

    SciTech Connect

    Baker, J.P.; Stephens, D.R.; Blanch, H.W.; Prausnitz, J.M.

    1992-09-01

    Temperature-sensitive N-isopropylacrylamide (NIPA)-based ampho-lytic hydrogels were synthesized by copolymerizing NIPA with the cationic monomer methacrylamidopropyl trimethylammonium chloride (MAPTAC) and the anionic monomer sodium styrene sulfonate (SSS). The total nominal charge density of the hydrogels was held constant at 8 mol % (dry basis), while the molar ratio of anionic to cationic moieties within the hydrogels was varied. Swelling equilibria were measured in water at 6C, and in aqueous sodium chloride solutions ranging in concentration from 10{sup {minus}5}to 5 M and temperature ranging from 6 to 56C. Consistent with expectations, the swelling behavior of the hydrogels was found to be controlled by temperature at low salt concentrations; as the sodium chloride concentration increased, temperature control of hydrogel swelling decreased. Slight antipolyelectrolyte behavior was observed for the hydrogel prepared with equal molar amounts of MAPTAC and SSS.

  15. Geoid height versus topography for oceanic plateaus and swells

    NASA Technical Reports Server (NTRS)

    Sandwell, David T.; Mackenzie, Kevin R.

    1989-01-01

    Gridded geoid height data (Marsh et al.l, 1986) and gridded bathymetry data (Van Wykhouse, 1973) are used to estimate the average compensation depths of 53 oceanic swells and plateaus. The relationship between geoid height and topography is examined using Airy and thermal compensation models. It is shown that geoid height is linearly related to topography between wavelengths of 400 and 4000 m as predicted by isostatic compensation models. The geoid/topography ratio is dependent on the average depth of compensation. The intermediate geoid/topography ratios of most thermal swells are interpreted as a linear combination of the decaying thermal swell signature and that of the persisting Airy-compensated volcanic edifice.

  16. OXIDATIVE PHOSPHORYLATION IN MITOCHONDRIA FROM LIVERS SHOWING CLOUDY SWELLING

    PubMed Central

    Fonnesu, Alberto; Severi, Clara

    1956-01-01

    Using succinate and α-ketoglutarate as substrates, oxidative phosphorylation has been measured in mitochondria isolated from livers showing cloudy swelling. This cellular change was obtained by injecting rats with S. typhi murium toxin and guinea pigs with diphtheria toxin. It has been found that phosphorylation associated with the oxidation of either of these substrates was partially inhibited in mitochondria from livers showing cloudy swelling, while the oxygen consumption was unchanged. Thus, the P:O ratios for both succinate and α-ketoglutarate were lower in mitochondria from treated animals than they were in normal mitochondria. Dephosphorylation of ATP was not significantly modified in mitochondria from livers showing cloudy swelling as compared with normal controls. No dephosphorylation of AMP and G-6-P was observed either in normal mitochondria or in mitochondria from treated animals. PMID:13331961

  17. Water uptake and swelling in single trabeculæ from human femur head

    PubMed Central

    Marinozzi, Franco; Bini, Fabiano; Marinozzi, Andrea

    2014-01-01

    The swelling of air-dried single trabeculae from human femur heads was obtained by complete immersion in water and the dimensional changes of the samples were measured over time. The experimental results were analyzed under the viewpoint of the diffusion through a porous material. The dimensional changes of the single trabeculae were 0.26 ± 0.15 percent (length), 0.45 ± 0.25 percent (width) and 1.86 ± 0.97 percent (thickness). The diffusion coefficients were then calculated from the swelling recorded over time and a value of (4.12 ± 0.8) x 10−10(m2s−1) (mean ± standard deviation) was found.   Since the dimensional variations of the specimens is due to the swelling of the collagen bone matrix, this technique could offer new insights for (1) a selective characterization of bone microstructure at the collagen matrix level and (2) the dynamics of diffusion through bone tissue. PMID:24553097

  18. Clay swelling and formation permeability reductions induced by a nonionic surfactant

    SciTech Connect

    Gardner, K.H.; Arias, M.S.

    2000-01-01

    A major concern with the use of surfactant flushing to mobilize nonaqueous phase liquids in aquifers is specific mineral-surfactant interactions that may effect significant permeability changes in the soil formation. Soils comprised of Ottawa sand mixed with small percentages of bentonite that had moderate initial hydraulic conductivity were investigated for loss of permeability upon flushing with solution containing a nonionic surfactant (polyoxyethylene sorbitan monooleate). Columns containing 0, 1, 2, 3, 4, and 5% had permeability reductions of 1, 5, 13, 44, 49, and 69%, respectively. The surfactant-clay interactions were further investigated as the cause of the permeability reductions. Some transport of clay through the column was apparent from a small amount of release measured. A permeability change was correlated with the colloid transport in the column with the highest clay concentration, although its effect was transient. Clay swelling was postulated as the primary mechanism for the permeability reductions. It was determined through X-ray diffraction that the surfactant was spreading the silica layer spacings of the clay from a hydration spacing of 15.23 {angstrom} to a surfactant-swelled spacing of 18.02 {angstrom}. A model was formulated to describe the reduced permeability by the increase in clay volume due to swelling measured by X-ray diffraction and was capable of describing the observed data well with an average error of approximately 10%.

  19. Effect of filler water absorption on water swelling properties of natural rubber

    NASA Astrophysics Data System (ADS)

    Trakuldee, J.; Boonkerd, K.

    2017-07-01

    The efficient water swelling rubber can be obtained by using high hydrophilic rubber such as chloroprene rubber. However, chloroprene rubber is synthetic rubber developed from the petroleum. Recently, many researches try to replace the usage of synthetic rubber with natural rubber. This is not only due to the concerning of environment but the cost reduction as well. However, natural rubber is hydrophobic, thus not absorbing water. To develop the water swelling rubber from natural rubber, the addition of water absorption filler is needed. The study was aimed to formulate water swelling rubber from natural rubber filled with sodium polyacrylate (SA)/sodium bentonite clay (SBC) hybrid filler used to water absorbent. The filler loading was kept constantly at 150 phr. The effect of SA/SBC ratio varied from 1:0, 1:1, 1:2 and 1:3 on the water absorption of the hybrid filled natural rubber was determined. The obtained result showed that the water adsorption proportionally increased with increasing SA loading but decreased with increasing SBC loading. The effect of glycidyl methacrylate (GM) and poly ethylene glycol (PEG) on the water absorption was studied later. The result from a scanning electron microscope depicted that the presence of GM can depress the falling out of SA from the rubber matrix while the presence of PEG increased water absorption.

  20. Swelling behavior and morphological evolution of mixed gelatin/silk fibroin hydrogels.

    PubMed

    Gil, Eun S; Frankowski, David J; Spontak, Richard J; Hudson, Samuel M

    2005-01-01

    Mixed protein-based hydrogels have been prepared by blending gelatin (G) with amorphous Bombyx mori silk fibroin (SF) and promoting beta-crystallization of SF via subsequent exposure to methanol or methanol/water solutions. The introduction of beta crystals in SF serves to stabilize the hydrogel network and extend the solidlike behavior of these thermally responsive materials to elevated temperatures beyond the helix-->coil (h-->c) transition of G. In this work, we investigate the swelling and protein release kinetics of G/SF hydrogels varying in composition at temperatures below and above the G h-->c transition. At 20 degrees C, G and G-rich mixed hydrogels display evidence of moderate swelling with negligible mass loss in aqueous solution, resulting in porous polymer matrixes upon solvent removal according to electron microscopy. When the solution temperature is increased beyond the G h-->c transition to body temperature (37 degrees C), these gels exhibit much higher swelling with considerable mass loss due to dissolution and release of G. The extent to which these properties respond to temperature decreases systematically with increasing SF content. The unique temperature- and composition-dependent properties of G/SF hydrogels dictate the efficacy of these novel materials as stimuli-responsive delivery vehicles.

  1. Sustainable and smart keratin hydrogel with pH-sensitive swelling and enhanced mechanical properties.

    PubMed

    Peralta Ramos, María Luz; González, Joaquín Antonio; Fabian, Lucas; Pérez, Claudio Javier; Villanueva, María Emilia; Copello, Guillermo Javier

    2017-09-01

    Protein based hydrogels are a very interesting type of biomaterials with many probed strengths related to their source and chemical structure. Biocompatibility and biodegradability are accompanied by affordability when it comes to low cost sources. The main keratin source is agroindustrial waste, such as feathers, horns, hooves, hair and wool. Thus, the main cost of keratin hydrogels derives from their processing. Here is presented a new strategy for the obtaining of a keratin hydrogel with enhanced mechanical properties using low cost reagents. This keratin hydrogel is stiff enough to allow handling without special cares and also presenting a reversible pH-responsive behavior. The minimum swelling is observed at low pH due to a collapsed and disordered protein network with water tightly adsorbed to the hydrophilic sites. The swelling rises significantly above pH6 and the maximum swelling appears above pH8 where an expanded network allows water to enter to the pores. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The theory of degassing and swelling of a supersaturated-by-gas solution

    NASA Astrophysics Data System (ADS)

    Kuchma, A. E.; Shchekin, A. K.; Bulgakov, M. Yu.

    2017-02-01

    The kinetic theory of degassing and swelling of a supersaturated-by-gas liquid solution under decompression has been formulated. The theory is based on the extended excluded volume approach to kinetics of gas-bubble nucleation. A description of the nucleation stage of supercritical gas-bubble formation with nonstationary nonuniform diffusion shells around the bubbles and mean-field mixing of the dissolved gas concentration at outer parts of the shells due to their stochastic overlapping has been built. In this way, the theory embraces the cases with any degree of initial gas supersaturation and deviation from the steady-state diffusion. It has been shown that the effects of nonstationary diffusion may be very significant in the growth of bubbles and, in particular, are responsible for a significant swelling of a supersaturated-by-gas liquid solution. Distribution of supercritical bubbles in sizes and gas concentration profiles at any moment of the nucleation stage as well as duration of the nucleation stage and the swelling ratio at the end of nucleation stage have been found.

  3. Swelling behavior of a simple ferritic alloy. [Fe-10% Cr

    SciTech Connect

    Horton, L.L.; Bentley, J.

    1983-01-01

    The swelling behavior which results from simulated fusion environment irradiation of Fe-10% Cr has been characterized with transmission electron microscopy. Specimens were bombarded at 850 K with: a triple-beam of He/sup +/, D/sup +//sub 2/, and 4 MeV Fe/sup + +/ ions to 0.3, 1, 3, 10, 30, and 100 dpa, a dual-beam of He/sup +/ and 4 MeV Fe/sup + +/ ions to 30 and 100 dpa; and a single-beam of 4 MeV Fe/sup + +/ ions to 30 dpa. The helium and hydrogen injection rates were approx. 10 appm He/dpa and approx. 40 appm D/dpa. Cavities were observed for damage levels of 3 dpa and greater. The swelling was <0.1% for damage levels <30 dpa, but at 100 dpa, there was an increase in the swelling to 2.5% for the triple-beam irradiation and 1.2% for the dual-beam irradiation. The swelling rates between 30 and 100 dpa correlate well with calculated values assuming a steady-state swelling-rate regime has been reached. Calculations show the rapid cavity growth associated with this swelling increase cannot be attributed to equilibrium bubble growth. For all of the bombardments, the cavities with a diameter greater than 10 nm had a truncated octahedral morphology with (111) facets and (100) truncations. Measurements indicate that the surface energy relationship was ..gamma../sub 111/approx. =0.8 ..gamma../sub 100/ for these cavities. At 30 dpa, the cavities in the specimen irradiated with the single-beam technique were larger and had a lower concentration than the specimens irradiated with specimens irradiated with the dual- and triple-ion beams suggests that deuterium has an effect on the damage microstructures in Fe-10% Cr.

  4. Space-time structure of long ocean swell fields

    NASA Astrophysics Data System (ADS)

    Delpey, Matthias T.; Ardhuin, Fabrice; Collard, Fabrice; Chapron, Bertrand

    2010-12-01

    The space-time structure of long-period ocean swell fields is investigated, with particular attention given to features in the direction orthogonal to the propagation direction. This study combines space-borne synthetic aperture radar (SAR) data with numerical model hindcasts and time series recorded by in situ instruments. In each data set the swell field is defined by a common storm source. The correlation of swell height time series is very high along a single great circle path with a time shift given by the deep water dispersion relation of the dominant swells. This correlation is also high for locations situated on different great circles in entire ocean basins. Given the Earth radius R, we define the distance from the source Rα and the transversal angle β so that α and β would be equal the colatitude and longitude for a storm centered on the North Pole. Outside of land influence, the swell height field at time t, Hss(α, β,t) is well approximated by a function Hss,0(t - Rα/Cg)/? times another function r2 (β), where Cg is a representative group speed. Here r2 (β) derived from SAR data is very broad, with a width at half the maximum that is larger than 70°, and varies significantly from storm to storm. Land shadows introduce further modifications so that in general r2 is a function of β and α. This separation of variables and the smoothness of the Hss field, allows the estimation of the full field of Hss from sparse measurements, such as wave mode SAR data, combined with one time series, such as that provided by a single buoy. A first crude estimation of a synthetic Hss field based on this principle already shows that swell hindcasts and forecasts can be improved by assimilating such synthetic observations.

  5. Nonuniform swelling-induced residual strains in articular cartilage.

    PubMed

    Narmoneva, D A; Wang, J Y; Setton, L A

    1999-04-01

    Swelling effects in cartilage originate from an interstitial osmotic pressure generated by the presence of negatively charged proteoglycans in the tissue. This swelling pressure gives rise to a non-zero residual strain in the cartilage solid matrix in the absence of externally applied loads. Previous studies have quantified swelling effects in cartilage as volumetric or dimensional change of excised samples in varying osmotically active solutions. This study presents a new optical technique for measuring two-dimensional swelling-induced residual strain fields in planar samples of articular cartilage attached to the bone (i.e., in situ). Osmotic loading was applied to canine cartilage bone samples by equilibration in external baths of varying NaCl concentration. Non-zero swelling-induced strains were measured in physiological saline, giving evidence of the existence of residual strains in articular cartilage. Only one component of planar strain (i.e., in thickness direction) was found to be non-zero. This strain was found to be highly non-uniform in the thickness direction, with evidence of compressive strain in the deep zone of cartilage and tensile strain in the middle and surface zones. The obtained results can be used to characterize the material properties of the articular cartilage solid matrix, with estimated values of 26 M Pa for the tensile modulus for middle zone cartilage. The method provides the basis to obtain material properties of the cartilage solid matrix from a simple, free-swelling test and may be useful for quantifying changes in cartilage properties with injury, degeneration and repair.

  6. [A pathogenetic hypothesis based on the use of chlorpromazine of organic disorders probably due to microcirculatory changes].

    PubMed

    Malossi, M

    1993-01-01

    In the introduction it is noted that, in the physiopathology, specific pathogenetic elements are missing concerning irritative stimulation, turbid fat pathosis, digital hippocratism of chronic affections (for example, pulmonary affections), the most frequent onset of telarche and of the swelling of the areola of the breast on the left hemithorax in the premenstrual syndrome, fibrosis, cyrrosis, certain types of insipid diabetes, etc. In the opinion of the author, the use of chloropromazine, in doses that have proved to be harmless, has contributed to the clearing up of some questions concerning a few pathologies of internal organs: the liver, the spleen, the brain-and enable us to pose some hypotheses about the swelling of the liver, the origin of scleroses and cirrhoses and some splenic and encephalic swellings. The author suggests that the fundamental reason is to be sought in changes in the microcirculation which are linked to insufficient capillary and sinusoidal circulation. Two cases of insipid diabetes are mentioned which were treated with chloropromazine and for which an improvement in the trophism of the diencephalic cells was hypothesized, due to an improvement in the local circulation. A similar physiopathological microcirculatory behaviour is attributed to digital hippocratism, the P. Marie and Bamberger syndrome (similar to those determined by cyanotic congenital cardiopathies), both due to chronic suppurative processes, and the slightly more frequent onset of telarche on the left hemithorax. It is expected that other pathologies may be explained by a similar physiopathological mechanism, malignant tumor inclusive.

  7. Rare cause of bilateral groin swelling: Round ligament varicosities

    PubMed Central

    Bulbul, Erdogan; Taskin, Mine Islimye; Yanik, Bahar; Demirpolat, Gulen; Adali, Ertan; Basbug, Murat

    2015-01-01

    Round ligament varicosity (RLV) is rare and almost all cases are pregnant women. RLV appears as a unilateral or bilateral groin swelling. Pain and tenderness may present. Clinical evaluation is inadequate for exact diagnosis because inguinal hernia has similar findings. Ultrasonography (US) is essential when a groin swelling is detected in a pregnant woman. We present gray scale US and colour Doppler US findings of a 32-week pregnant woman with bilateral RLVs at the inguinal canal, parauterine area and in the myometrium. PMID:26430450

  8. Strategies used to inhibit postoperative swelling following removal of impacted lower third molar

    PubMed Central

    Sortino, Francesco; Cicciù, Marco

    2011-01-01

    Postoperative swelling following different surgical strategies is an area of great interest. The main part of literature on the topic deals with swelling after extraction of low impacted third molar. In this review, we have analyzed publications of the last 20 years with a pubmed search using the following key words: impacted third molar, swelling third molar, wisdom tooth, edema jaw, corticosteroids and extraction third molar, antibiotic prophylaxis and tooth extraction. Attention has often been focused on corticosteroid therapy administered by diverse routes (orally, IV, IM, topically) and at different time schedules (before or after surgery or both). This investigation revealed how the use of different molecules and dosages makes the obtained results hardly comparable. Similar conclusions can be drawn from studies aimed at evaluating the efficacy of antibiotic therapy administered either before or after surgery. A complete review has also to take into account different surgical strategies used including various flaps, no traumatic osteothomy, and primary or secondary closure. The use of pharmacological therapy and application of an ice pack is critical in the postoperative period and has always provided positive results. However, even if it is difficult to come to definite conclusions, due to the variability of the design of studies analyzed, the postoperative discomfort identified with edema, pain and trismus following wisdom tooth removal is influenced by various factors such as the difficulty of the surgical procedure involved, age and gender of the patient, and experience of the surgeon. The pharmacological therapy when performed with corticosteroids seems to improve control of the postoperative swelling related with this kind of surgeries. PMID:22135686

  9. Alteration of default mode network in high school football athletes due to repetitive subconcussive mild traumatic brain injury: a resting-state functional magnetic resonance imaging study.

    PubMed

    Abbas, Kausar; Shenk, Trey E; Poole, Victoria N; Breedlove, Evan L; Leverenz, Larry J; Nauman, Eric A; Talavage, Thomas M; Robinson, Meghan E

    2015-03-01

    Long-term neurological damage as a result of head trauma while playing sports is a major concern for football athletes today. Repetitive concussions have been linked to many neurological disorders. Recently, it has been reported that repetitive subconcussive events can be a significant source of accrued damage. Since football athletes can experience hundreds of subconcussive hits during a single season, it is of utmost importance to understand their effect on brain health in the short and long term. In this study, resting-state functional magnetic resonance imaging (rs-fMRI) was used to study changes in the default mode network (DMN) after repetitive subconcussive mild traumatic brain injury. Twenty-two high school American football athletes, clinically asymptomatic, were scanned using the rs-fMRI for a single season. Baseline scans were acquired before the start of the season, and follow-up scans were obtained during and after the season to track the potential changes in the DMN as a result of experienced trauma. Ten noncollision-sport athletes were scanned over two sessions as controls. Overall, football athletes had significantly different functional connectivity measures than controls for most of the year. The presence of this deviation of football athletes from their healthy peers even before the start of the season suggests a neurological change that has accumulated over the years of playing the sport. Football athletes also demonstrate short-term changes relative to their own baseline at the start of the season. Football athletes exhibited hyperconnectivity in the DMN compared to controls for most of the sessions, which indicates that, despite the absence of symptoms typically associated with concussion, the repetitive trauma accrued produced long-term brain changes compared to their healthy peers.

  10. Pediatric Sialadenosis Due to Valproic Acid.

    PubMed

    Derin, Hatice; Derin, Serhan; Oltulu, Pembe; Özbek, Orhan; Çaksen, Hüseyin

    2016-12-23

    Sialadenosis is a rare entity characterized by bilateral diffuse, painless swelling of the parotid glands. Its etiology is not clear; however, it may occur due to adverse effects of some drugs. To our knowledge, sialadenosis due to valproic acid has not been reported in the literature up to date in any child. In this article, the authors presented a child who developed sialadenosis due to valproic acid, and improved after stopping use of the drug.

  11. Hydrogel films and coatings by swelling-induced gelation.

    PubMed

    Moreau, David; Chauvet, Caroline; Etienne, François; Rannou, François P; Corté, Laurent

    2016-11-22

    Hydrogel films used as membranes or coatings are essential components of devices interfaced with biological systems. Their design is greatly challenged by the need to find mild synthesis and processing conditions that preserve their biocompatibility and the integrity of encapsulated compounds. Here, we report an approach to produce hydrogel films spontaneously in aqueous polymer solutions. This method uses the solvent depletion created at the surface of swelling polymer substrates to induce the gelation of a thin layer of polymer solution. Using a biocompatible polymer that self-assembles at high concentration [poly(vinyl alcohol)], hydrogel films were produced within minutes to hours with thicknesses ranging from tens to hundreds of micrometers. A simple model and numerical simulations of mass transport during swelling capture the experiments and predict how film growth depends on the solution composition, substrate geometry, and swelling properties. The versatility of the approach was verified with a variety of swelling substrates and hydrogel-forming solutions. We also demonstrate the potential of this technique by incorporating other solutes such as inorganic particles to fabricate ceramic-hydrogel coatings for bone anchoring and cells to fabricate cell-laden membranes for cell culture or tissue engineering.

  12. Corn Mitochondrial Swelling and Contraction—an Alternate Interpretation 1

    PubMed Central

    Malone, Carl; Koeppe, D. E.; Miller, Raymond J.

    1974-01-01

    Mitochondria isolated from 3-day-old etiolated corn shoots (Zea mays L.) can be categorized into three separate groups, each group characteristic of the cell type from which the mitochondria were isolated. Phloem sieve tubes and some adjacent parenchyma cells contain mitochondria that have few cristae and little amorphous matrix. Mitochondria from meristematic and undifferentiated cells have more cristae and matrix. Vaculate and differentiated cells have mitochondria with well-developed cristae and abundant matrix. Each mitochondrial type exhibits typical in vitro spontaneous swelling and substrate-induced contraction responses. characterized by change or lack of change in cristae size and in density of amorphous material. For the second and third types of mitochondria, swelling and contraction are characterized by a change in degree of cristae size and in matrix density. The first type undergoes few changes upon swelling or contraction. Radical changes of the inner membrane, withdrawal and infolding, are associated with cell differentiation and not with swelling and contraction of isolated corn shoot mitochondria. Images PMID:16658816

  13. Absorption and swelling characteristics of silver (I) antimicrobial wound dressings

    USDA-ARS?s Scientific Manuscript database

    An important characteristic of moist wound dressings is their ability to swell and absorb exudates from the wound, while maintaining a moist atmosphere at the wound site. At the Southern Regional Research Center (SRRC), we have previously developed antimicrobial silver-sodium-carboxymethylated (CM)-...

  14. Lupus erythematosus--a case of facial swelling.

    PubMed

    Loescher, A; Edmondson, H D

    1988-04-01

    A case is reported of acute facial swelling following tooth extraction that failed to respond in a normal manner. The patient developed systemic signs and symptoms ultimately revealing the diagnosis of lupus erythematosus. The possibility of soft tissue lesions arising in some forms of lupus is emphasised by this report.

  15. Hydrogel films and coatings by swelling-induced gelation

    PubMed Central

    Moreau, David; Chauvet, Caroline; Etienne, François; Rannou, François P.

    2016-01-01

    Hydrogel films used as membranes or coatings are essential components of devices interfaced with biological systems. Their design is greatly challenged by the need to find mild synthesis and processing conditions that preserve their biocompatibility and the integrity of encapsulated compounds. Here, we report an approach to produce hydrogel films spontaneously in aqueous polymer solutions. This method uses the solvent depletion created at the surface of swelling polymer substrates to induce the gelation of a thin layer of polymer solution. Using a biocompatible polymer that self-assembles at high concentration [poly(vinyl alcohol)], hydrogel films were produced within minutes to hours with thicknesses ranging from tens to hundreds of micrometers. A simple model and numerical simulations of mass transport during swelling capture the experiments and predict how film growth depends on the solution composition, substrate geometry, and swelling properties. The versatility of the approach was verified with a variety of swelling substrates and hydrogel-forming solutions. We also demonstrate the potential of this technique by incorporating other solutes such as inorganic particles to fabricate ceramic-hydrogel coatings for bone anchoring and cells to fabricate cell-laden membranes for cell culture or tissue engineering. PMID:27821765

  16. Swelling and drug release from oral thin films (OTFs)

    NASA Astrophysics Data System (ADS)

    Adrover, A.; Casadei, M. A.; Paolicelli, P.; Petralito, S.; Varani, G.

    2016-05-01

    We investigate the characteristic time-scales for swelling and drug release from polymeric thin films for buccal delivery. In this work, novel OTFs were prepared combining Gellan gum, a natural polysaccharide well known in the pharmaceutical field, along with Glycerol, used as plasticizer. A new millifluidic flow-through device is adopted for in-vitro release tests.

  17. Bulk Etch Rate and Swell Rate of CR-39

    NASA Astrophysics Data System (ADS)

    Clarkson, David; Ume, Rubab; Sheets, Rebecca; Regan, Sean; Sangster, Craig; Padalino, Stephen; McLean, James

    2016-10-01

    The use of CR-39 plastic as a Solid State Nuclear Track Detector is an effective technique for obtaining data in high-energy particle experiments including inertial confinement fusion. To reveal particle tracks after irradiation, CR-39 is chemically etched in NaOH at 80°C, producing micron-scale signal pits at the nuclear track sites. The development of these pits depends on both the bulk etch rate and the faster etch rate along the track, and is complicated by swelling as water is absorbed. Contrary to common etching models, we find the bulk etch rate to be depth dependent within 15 μ m of the surface, as revealed by swelling TASTRACK CR-39 pieces to their maximum capacity prior to etching. The bulk etch rate was measured using the standard mass method as well as the fission fragment track diameter method. Combining models of swelling and etching rates predicts the progress of bulk etching during a standard etch, without pre-swelling. This result has implications for the understanding the chemistry of the etch process, as well as the outcome of CR-39 surface preparation methods. Funded in part by a LLE contract through the DOE.

  18. Demonstration of Solvent Differences by Visible Polymer Swelling.

    ERIC Educational Resources Information Center

    Ross, Joseph H.

    1983-01-01

    Effect of the "polarity" of low-polarity solvents on the amount of swelling produced in a solid polymer (demonstrated in an organic chemistry lecture) is also suitable as a laboratory experiment. Students can be assigned to a small group of solvents from the list provided. Procedures and materials needed are included. (Author/JN)

  19. Sternocostoclavicular Joint Swelling; Diagnosis of a Neglected Entity

    PubMed Central

    Sharma, Deep; Dhiman, Pooja; Menon, Jagdish; Krishna, Komuravalli Varun

    2015-01-01

    Background: Sternocostoclavicular joint (SCCJ) swelling is an underdiagnosed, albeit important entity in clinical practice. The present study was conducted in order to identify the incidence and common causes of this entity. Methods: Patients presenting to the Orthopaedic Clinic with a swelling of the sternocostoclavicular joint, during the study period of two years were included, and detailed history was obtained from the patient. Baseline investigations (total and differential leukocyte count, ESR, CRP, X-ray and CT) wereperformed. Magnetic resonance imaging,FNAC or joint aspiration was performed whenever clinically or radiologically indicated. Results: A total of 21 patients were enrolled into the study for a duration of 2 years. Patients mainly presented with both pain and swelling of the SCCJ with predominant right sided involvement. Osteoarthritis was the most frequent diagnosis followed by infections, primary bone/cartilage tumor, and metastasis. Conclusions: Although most of the patients with SCCJ swelling have a benign etiology, it is not wise to dismiss thisswelling as degenerative changes. Serious conditions like septic arthritis or neoplasia, may masquerade with similar presentations such as osteoarthritis. It would be therefore imperative to rule out all of these potentially life threatening conditions using thorough clinic-radiological workups. PMID:26110174

  20. Mechanically robust, negative-swelling, mussel-inspired tissue adhesives.

    PubMed

    Barrett, Devin G; Bushnell, Grace G; Messersmith, Phillip B

    2013-05-01

    Most synthetic polymer hydrogel tissue adhesives and sealants swell considerably in physiologic conditions, which can result in mechanical weakening and adverse medical complications. This paper describes the synthesis and characterization of mechanically tough zero- or negative-swelling mussel-inspired surgical adhesives based on catechol-modified amphiphilic poly(propylene oxide)-poly(ethylene oxide) block copolymers. The formation, swelling, bulk mechanical, and tissue adhesive properties of the resulting thermosensitive gels were characterized. Catechol oxidation at or below room temperature rapidly resulted in a chemically cross-linked network, with subsequent warming to physiological temperature inducing a thermal hydrophobic transition in the PPO domains and providing a mechanism for volumetric reduction and mechanical toughening. The described approach can be easily adapted for other thermally sensitive block copolymers and cross-linking strategies, representing a general approach that can be employed to control swelling and enhance mechanical properties of polymer hydrogels used in a medical context. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Uncommon inflammatory swelling of the lips: orofacial granulomatosis.

    PubMed

    Hafiz, Abdul; Mufeed, Abdulla; Kandasamy, Gopinath; Krishnapillai, Rekha

    2016-01-12

    Orofacial granulomatosis (OFG) is an unusual condition associated with permanent or recurrent swelling of orofacial tissues together with oral mucosal ulceration and a variety of orofacial characteristics. The chronic inflammation inherent to OFG often displays granulomas in the subepithelial stroma. We present a case of OFG and its management. The patient responded to intralesional injections of corticosteroids.

  2. Shrink-swell behavior of soil across a vertisol catena

    USDA-ARS?s Scientific Manuscript database

    Shrinking and swelling of soils and the associated formation and closing of cracks can vary spatially within the smallest hydrologic unit subdivision utilized in surface hydrology models. Usually in the application of surface hydrology models, cracking is not considered to vary within a hydrologic u...

  3. Linear Viscoelasticity and Swelling of Polyelectrolyte Complex Coacervates

    NASA Astrophysics Data System (ADS)

    Hamad, Fawzi; Colby, Ralph

    2012-02-01

    The addition of near equimolar amounts of poly(diallyldimethylammonium chloride) to poly(isobutylene-alt-maleate sodium), results in formation of a polyelectrolyte complex coacervate. Zeta-potential titrations conclude that these PE-complexes are nearly charge-neutral. Swelling and rheological properties are studied at different salt concentrations in the surrounding solution. The enhanced swelling observed at high salt concentration suggests the system behaves like a polyampholyte gel, and weaker swelling at very low salt concentrations implies polyelectrolyte gel behavior. Linear viscoelastic oscillatory shear measurements indicate that the coacervates are viscoelastic liquids and that increasing ionic strength of the medium weakens the electrostatic interactions between charged units, lowering the relaxation time and viscosity. We use the time-salt superposition idea recently proposed by Spruijt, et al., allowing us to construct master curves for these soft materials. Similar swelling properties observed when varying molecular weights. Rheological measurements reveal that PE-complexes with increasing molecular weight polyelectrolytes form a network with higher crosslink density, suggesting time-molecular weight superposition idea.

  4. Advanced liquefaction using coal swelling and catalyst dispersion techniques

    SciTech Connect

    Curtis, C.W. ); Gutterman, C. ); Chander, S. )

    1992-08-26

    Research in this project centers upon developing a new approach to the direct liquefaction of coal to produce an all-distillate product slate at a sizable cost reduction over current technology. The approach integrates all aspects of the coal liquefaction process including coal selection, pretreatment, coal swelling with catalyst impregnation, coal liquefaction experimentation, product recovery with characterization, alternate bottoms processing, and a technical assessment including an economic evaluation. The project is being carried out under contract to the United States Department of Energy. On May 28, 1992, the Department of Energy authorized starting the experimental aspects of this projects; therefore, experimentation at Amoco started late in this quarterly report period. Research contracts with Auburn University, Pennsylvania State University, and Foster Wheeler Development Corporation were signed during June, 1992, so their work was just getting underway. Their work will be summarized in future quarterly reports. A set of coal samples were sent to Hazen Research for beneficiation. The samples were received and have been analyzed. The literature search covering coal swelling has been up-dated, and preliminary coal swelling experiments were carried out. Further swelling experimentation is underway. An up-date of the literature on the liquefaction of coal using dispersed catalysts is nearing completion; it will be included in the next quarterly report.

  5. Curcumin micelles improve mitochondrial function in neuronal PC12 cells and brains of NMRI mice - Impact on bioavailability.

    PubMed

    Hagl, Stephanie; Kocher, Alexa; Schiborr, Christina; Kolesova, Natalie; Frank, Jan; Eckert, Gunter P

    2015-10-01

    Curcumin, a polyphenolic compound abundant in the rhizome of Curcuma longa, has been reported to have various beneficial biological and pharmacological activities. Recent research revealed that curcumin might be valuable in the prevention and therapy of numerous disorders including neurodegenerative diseases like Alzheimer's disease. Due to its low absorption and quick elimination from the body, curcumin bioavailability is rather low which poses major problems for the use of curcumin as a therapeutic agent. There are several approaches to ameliorate curcumin bioavailability after oral administration, amongst them simultaneous administration with secondary plant compounds, micronization and micellation. We examined bioavailability in vivo in NMRI mice and the effects of native curcumin and a newly developed curcumin micelles formulation on mitochondrial function in vitro in PC12 cells and ex vivo in isolated mouse brain mitochondria. We found that curcumin micelles improved bioavailability of native curcumin around 10- to 40-fold in plasma and brain of mice. Incubation with native curcumin and curcumin micelles prevented isolated mouse brain mitochondria from swelling, indicating less mitochondrial permeability transition pore (mPTP) opening and prevention of injury. Curcumin micelles proved to be more efficient in preventing mitochondrial swelling in isolated mouse brain mitochondria and protecting PC12 cells from nitrosative stress than native curcumin. Due to their improved effectivity, curcumin micelles might be a suitable formulation for the prevention of mitochondrial dysfunction in brain aging and neurodegeneration.

  6. Irradiated PVAl membrane swelled with chitosan solution as dermal equivalent

    NASA Astrophysics Data System (ADS)

    Rodas, A. C. D.; Ohnuki, T.; Mathor, M. B.; Lugao, A. B.

    2005-07-01

    Synthetic membranes as dermal equivalent can be applied at in vitro studies for developing new transdermal drugs or cosmetics. These membranes could be composed to mimic the dermis and seed cultivated keratinocytes as epidermal layer on it. The endothelial cells ingrowth to promote neovascularization and fibroblasts ingrowth to promote the substitution of this scaffold by natural components of the dermis. As, they can mimic the scaffold function of dermis; the membranes with biological interaction could be used for in vivo studies as dermal equivalent. For this application, poly(vinyl alcohol) (PVAl) membranes crosslinked by gamma radiation were swelled with chitosan solution. PVAl do not interact with the organism when implanted and is intended to mimic the mechanical characteristics of the dermal scaffold. The chitosan as a biocompatible biosynthetic polysaccharide were incorporated into PVAl membranes to improve the organism response. Degradation of chitosan by the organism occurs preferably by hydrolysis or enzymatic action, for example, by lysozyme. For this purpose the swelling kinetic of PVAl membranes with chitosan solution were performed and it was verified their degradation in vitro. The results showed that the swelling equilibrium of the PVAl membranes with chitosan membranes was reached in 120 h with average swelling of 1730%. After swelling, PVAl and chitosan/PVAl membranes were dried and immersed in phosphate buffer solution pH 5.7 and pH 7.4, with and without lysozyme, as those pH values are the specific physiologic pH for external skin and the general physiological pH for the organism, respectively. It was verified that the pure PVAl membrane did not showed change in their mass during 14 days. PVAl membranes swelled with chitosan solution showed mass decrease from 1 to 14 days inside these solutions. The highest mass decrease was verified at pH 5.7 in phosphate buffer solution without lysozyme. The smallest mass decrease was verified at pH 7.4 in

  7. Swelling and Eicosanoid Metabolites Differentially Gate TRPV4 Channels in Retinal Neurons and Glia

    PubMed Central

    Ryskamp, Daniel A.; Jo, Andrew O.; Frye, Amber M.; Vazquez-Chona, Felix; MacAulay, Nanna; Thoreson, Wallace B.

    2014-01-01

    Activity-dependent shifts in ionic concentrations and water that accompany neuronal and glial activity can generate osmotic forces with biological consequences for brain physiology. Active regulation of osmotic gradients and cellular volume requires volume-sensitive ion channels. In the vertebrate retina, critical support to volume regulation is provided by Müller astroglia, but the identity of their osmosensor is unknown. Here, we identify TRPV4 channels as transducers of mouse Müller cell volume increases into physiological responses. Hypotonic stimuli induced sustained [Ca2+]i elevations that were inhibited by TRPV4 antagonists and absent in TRPV4−/− Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, characterized by slow-onset and Ca2+ waves, and, in excess, were sufficient to induce reactive gliosis. In contrast, neurons responded to TRPV4 agonists and swelling with fast, inactivating Ca2+ signals that were independent of phospholipase A2. Our results support a model whereby swelling and proinflammatory signals associated with arachidonic acid metabolites differentially gate TRPV4 in retinal neurons and glia, with potentially significant consequences for normal and pathological retinal function. PMID:25411497

  8. Swelling and eicosanoid metabolites differentially gate TRPV4 channels in retinal neurons and glia.

    PubMed

    Ryskamp, Daniel A; Jo, Andrew O; Frye, Amber M; Vazquez-Chona, Felix; MacAulay, Nanna; Thoreson, Wallace B; Križaj, David

    2014-11-19

    Activity-dependent shifts in ionic concentrations and water that accompany neuronal and glial activity can generate osmotic forces with biological consequences for brain physiology. Active regulation of osmotic gradients and cellular volume requires volume-sensitive ion channels. In the vertebrate retina, critical support to volume regulation is provided by Müller astroglia, but the identity of their osmosensor is unknown. Here, we identify TRPV4 channels as transducers of mouse Müller cell volume increases into physiological responses. Hypotonic stimuli induced sustained [Ca(2+)]i elevations that were inhibited by TRPV4 antagonists and absent in TRPV4(-/-) Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, characterized by slow-onset and Ca(2+) waves, and, in excess, were sufficient to induce reactive gliosis. In contrast, neurons responded to TRPV4 agonists and swelling with fast, inactivating Ca(2+) signals that were independent of phospholipase A2. Our results support a model whereby swelling and proinflammatory signals associated with arachidonic acid metabolites differentially gate TRPV4 in retinal neurons and glia, with potentially significant consequences for normal and pathological retinal function. Copyright © 2014 the authors 0270-6474/14/3415689-12$15.00/0.

  9. Poly(Vinyl Alcohol)/Poly(Acrylic Acid) Hydrogel in a dc Electric Field: Swelling, Shape Change, and Actuation Characteristics

    PubMed Central

    2014-01-01

    Poly(vinyl alcohol) (PVA)/Poly(acrylic acid) (PAA) hydrogel can be utilized as a biomimetic actuator and coating material for tissue-implant interface, when employing an electrical stimulus. The swelling, shape change, and actuation characteristics of PVA/PAA hydrogel in a range of dc electrical fields were determined to find the optimal electric field for the hydrogel application as biomimetic actuator and coating materials. The hydrogel samples were prepared by dissolving PVA and PAA in deionized water at 4 wt% and mixed together at 1:1 ratio. Two custom made experimental setups were fabricated; one used for the measurement of swelling ratio of the hydrogels; and the other used for the shape changes or actuation characteristics of the hydrogels. Swelling experiments show increased swelling ratios of the hydrogel due to 10 V, 20 V, and 30 V electric fields. The rate of increment of the swelling ratio of hydrogel samples under 10V was higher compare to those samples under 20 V and 30 V. The width and height changes of rectangular shapes and maximum deflection along the length of hydrogel sample due to a range of electric fields (0-30V) were measured using an optical microscope. Incremental shape change up to a specific threshold value (around 10V) was observed due to electric stimulus. Electrostatic actuation pressure of hydrogel samples under 10V was higher compare to those samples under 20 V and 30 V. These results suggested that optimal performance of PVA/PAA hydrogel can be achieved around 10V. PMID:25478321

  10. Crossing Swell and Origins: Global View from ASAR Wave Mode Fireworks

    NASA Astrophysics Data System (ADS)

    Wang, He; Mouche, Alexis; Husson, Romain; Chapron, Bertrand; Yang, Jingsong

    2016-08-01

    Crossing swell, is a complicated sea state characterized by the co-existence of swell systems generating from different swell origins. Although many investigations have focused on the global swell climatology, our understanding of global statistical distribution for the crossing swell is still limited. In this paper, we present a global view of crossing swell using 10-years Synthetic Aperture Radar (SAR) derived directional swell spectra from Envisat ASAR in Wave Mode from 2003 to 2011. In contrast to analyze the directly but occasionally SAR captured sea state of crossing swell, we employ an approach of propagating observed swell taking advantage of the internal consistency of swells. Results reveal three dominated crossing swell areas termed "crossing swell pools", in Pacific, Atlantic and Indian Oceans. The pool in Atlantic Ocean shows a relative stable behaviour for all seasons, in contrast to the one in Indian Ocean with seasonal occurrence and the one in Pacific Ocean shrinking during boreal summer. The sources of the crossing swell are also inferred from ASAR wave mode data, and its global distribution analysis results indicate good agreement with the seasonal variation of crossing swell pools.

  11. Efavirenz and Metabolites in Cerebrospinal Fluid: Relationship with CYP2B6 c.516G→T Genotype and Perturbed Blood-Brain Barrier Due to Tuberculous Meningitis

    PubMed Central

    Chau, Tran Thi Hong; Fisher, Martin; Nelson, Mark; Winston, Alan; Else, Laura; Carr, Daniel F.; Taylor, Steven; Ustianowski, Andrew; Back, David; Pirmohamed, Munir; Solomon, Tom; Farrar, Jeremy; Törok, M. Estée; Khoo, Saye

    2016-01-01

    Efavirenz (EFZ) has been associated with neuropsychiatric side effects. Recently, the 8-hydroxy-EFZ (8OH-EFZ) metabolite has been shown to be a potent neurotoxin in vitro, inducing neuronal damage at concentrations of 3.3 ng/ml. EFZ induced similar neuronal damage at concentrations of 31.6 ng/ml. We investigated the effect of genotype and blood-brain barrier integrity on EFZ metabolite concentrations in cerebrospinal fluid (CSF). We measured CSF drug concentrations in subjects from two separate study populations: 47 subjects with tuberculous meningitis (TBM) coinfection in Vietnam receiving 800 mg EFZ with standard antituberculous treatment and 25 subjects from the PARTITION study in the United Kingdom without central nervous system infection receiving 600 mg EFZ. EFZ and metabolite concentrations in CSF and plasma were measured and compared with estimates of effectiveness and neurotoxicity from available published in vitro and in vivo data. The effect of the CYP2B6 c.516G→T genotype (GG genotype, fast EFV metabolizer status; GT genotype, intermediate EFV metabolizer status; TT genotype, slow EFV metabolizer status) was examined. The mean CSF concentrations of EFZ and 8OH-EFZ in the TBM group were 60.3 and 39.3 ng/ml, respectively, and those in the no-TBM group were 15.0 and 5.9 ng/ml, respectively. Plasma EFZ and 8OH-EFZ concentrations were similar between the two groups. CSF EFZ concentrations were above the in vitro toxic concentration in 76% of samples (GG genotype, 61%; GT genotype, 90%; TT genotype, 100%) in the TBM group and 13% of samples (GG genotype, 0%; GT genotype, 18%; TT genotype, 50%) in the no-TBM group. CSF 8OH-EFZ concentrations were above the in vitro toxic concentration in 98% of the TBM group and 87% of the no-TBM group; levels were independent of genotype but correlated with the CSF/plasma albumin ratio. Potentially neurotoxic concentrations of 8OH-EFZ are frequently observed in CSF independently of the CYP2B6 genotype, particularly in those

  12. In aging, the vulnerability of rat brain mitochondria is enhanced due to reduced level of 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNP) and subsequently increased permeability transition in brain mitochondria in old animals.

    PubMed

    Krestinina, Olga; Azarashvili, Tamara; Baburina, Yulia; Galvita, Anastasia; Grachev, Dmitry; Stricker, Rolf; Reiser, Georg

    2015-01-01

    Aging is accompanied by progressive dysfunction of mitochondria associated with a continuous decrease of their capacity to produce ATP. Mitochondria isolated from brain of aged animals show an increased mitochondrial permeability transition pore (mPTP) opening. We recently detected new regulators of mPTP function in brain mitochondria, the enzyme 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP) and its substrates 2', 3'-cAMP and 2', 3'-cNADP, and the neuronal protein p42(IP4). Here, we compared parameters of mPTP opening in non-synaptic brain mitochondria isolated from young and old rats. In mitochondria from old rats (>18 months), mPTP opening occurred at a lower threshold of Ca(2+) concentration than in mitochondria from young rats (<3 months). mPTP opening in mitochondria from old rats was accelerated by 2', 3'-cAMP, which further lowered the threshold Ca(2+) concentration. In non-synaptic mitochondria from old rats, the CNP level was decreased by 34%. Lowering of the CNP level in non-synaptic mitochondria with aging was accompanied by decreased levels of voltage-dependent anion channel (VDAC; by 69%) and of p42(IP4) (by 59%). Thus, reduced levels of CNP in mitochondria could lead to a rise in the concentration of the mPTP promoter 2', 3'-cAMP. The level of CNP and p42(IP4) and, probably VDAC, might be essential for myelination and electrical activity of axons. We propose that in aging the reduction in the level of these proteins leads to mitochondrial dysfunction, in particular, to a decreased threshold Ca(2+) concentration to induce mPTP opening. This might represent initial steps of age-related mitochondrial dysfunction, resulting in myelin and axonal pathology.

  13. Swelling of Erectile Nasal Tissue Induced by Human Sexual Pheromone.

    PubMed

    Mazzatenta, Andrea; De Luca, C; Di Tano, A; Cacchio, M; Di Giulio, C; Pokorski, Mieczyslaw

    2016-01-01

    Most chemically mediated sexual communication in humans remains uncharacterized. Yet the study of sexual communication is decisive for understanding sexual behavior and evolutive mechanisms in our species. Here we provide the evidence to consider 4,16-androstadien-3-one (AND) as a man's sexual pheromone. Our experiment provides support for the physiological effect of AND on nasal airway resistance (Rna) in women, as assessed by anterior rhinomanometry. We found that AND administration increased the area of turbinate during the ovulatory phase, resulting in an increase of Rna. Thus, we discovered that minute amounts of AND, acting through neuroendocrine brain control, regulate Rna and consequently affect the sexual physiology and behavior. Fascinatingly, this finding provides the evidence of the preservation of chemosexual communication in humans, which it has been largely neglected due to its unconscious perception and concealed nature. Therefore, chemical communication is a plesiomorphic evolutive phenomenon in humans.

  14. Adult neural progenitor cells from Huntington's disease mouse brain exhibit increased proliferation and migration due to enhanced calcium and ROS signals.

    PubMed

    Xie, Wenjuan; Wang, Jiu-Qiang; Wang, Qiao-Chu; Wang, Yun; Yao, Sheng; Tang, Tie-Shan

    2015-10-01

    Huntington's disease (HD) is an inherited human neurodegenerative disorder characterized by uncontrollable movement, psychiatric disturbance and cognitive decline. Impaired proliferative/differentiational potentials of adult neural progenitor cells (ANPCs) have been thought to be a pathogenic mechanism involved in it. In this study, we aimed to elucidate intrinsic properties of ANPCs subjected to neurodegenerative condition in YAC128 HD mice. ANPCs were isolated from the SVZ regions of 4-month-old WT and YAC128 mice. Cell proliferation, migration and neuronal differentiation in vitro were compared between these two genotypes with/without Ca(2+) inhibitors or ROS scavenger treatments. Differences in ANPC proliferation and differentiation capabilities in vivo between the two genotypes were evaluated using Ki-67 and Doublecortin (DCX) immunofluorescence respectively. Compared to WT ANPCs, YAC128 ANPCs had significantly enhanced cell proliferation, migration and neuronal differentiation in vitro, accompanied by increased Ca(2+) and ROS signals. Raised proliferation and migration in YAC128 ANPCs were abolished by Ca(2+) signalling antagonists and ROS scavenging. However, in vivo, HD ANPCs failed to show any elevated proliferation or differentiation. Increased Ca(2+) signalling and higher level of ROS conferred HD ANPC enhancement of proliferation and migration potentials. However, the in vivo micro-environment did not support endogenous ANPCs to respond appropriately to neuronal loss in these YAC128 mouse brains. © 2015 John Wiley & Sons Ltd.

  15. MRI detection of weak magnetic fields due to an extended current dipole in a conducting sphere: a model for direct detection of neuronal currents in the brain.

    PubMed

    Konn, Daniel; Gowland, Penny; Bowtell, Richard

    2003-07-01

    To investigate the feasibility of direct MR detection of neuronal activity in the brain, neuronal current flow was modeled as an extended current dipole located in a conducting sphere. The spatially varying magnetic field induced within the sphere by such a dipole was calculated, including its form close to and within the current source. The predicted field variation was experimentally verified by measurements of the variation in phase of the MR signal in a sphere containing a model dipole. The effects of the calculated magnetic field distributions on the phase and magnitude of the signal in MR images were explored. The minimum detectable dipole strength under normal experimental conditions was calculated to be about 4.5 nAm, which is similar in magnitude to dipole strengths from evoked neuronal activity, and is an order of magnitude smaller than dipole strengths expected from spontaneous activity. This minimum detectable dipole strength increases with increasing spatial extent of the primary current distribution. In the experimental work, the effects of a field of [1.1 +/- 0.5] x 10(-10) T strength were detected, corresponding to the maximum net field caused by a dipole of 6.3 nAm strength with a spatial extent of 3 x 3 x 2 mm(3). Copyright 2003 Wiley-Liss, Inc.

  16. Near-infrared spectroscopy (NIRS)-based eyes-closed brain-computer interface (BCI) using prefrontal cortex activation due to mental arithmetic

    PubMed Central

    Shin, Jaeyoung; Müller, Klaus-R; Hwang, Han-Jeong

    2016-01-01

    We propose a near-infrared spectroscopy (NIRS)-based brain-computer interface (BCI) that can be operated in eyes-closed (EC) state. To evaluate the feasibility of NIRS-based EC BCIs, we compared the performance of an eye-open (EO) BCI paradigm and an EC BCI paradigm with respect to hemodynamic response and classification accuracy. To this end, subjects performed either mental arithmetic or imagined vocalization of the English alphabet as a baseline task with very low cognitive loading. The performances of two linear classifiers were compared; resulting in an advantage of shrinkage linear discriminant analysis (LDA). The classification accuracy of EC paradigm (75.6 ± 7.3%) was observed to be lower than that of EO paradigm (77.0 ± 9.2%), which was statistically insignificant (p = 0.5698). Subjects reported they felt it more comfortable (p = 0.057) and easier (p < 0.05) to perform the EC BCI tasks. The different task difficulty may become a cause of the slightly lower classification accuracy of EC data. From the analysis results, we could confirm the feasibility of NIRS-based EC BCIs, which can be a BCI option that may ultimately be of use for patients who cannot keep their eyes open consistently. PMID:27824089

  17. Risk of hospitalization due to motor vehicle crashes among Iraq and Afghanistan War Veterans diagnosed with traumatic brain injury.

    PubMed

    Carlson, Kathleen F; O'Neil, Maya E; Forsberg, Christopher W; McAndrew, Lisa M; Storzbach, Daniel; Cifu, David X; Sayer, Nina A

    2016-06-30

    Traumatic brain injury (TBI) was deemed the 'signature injury' of the Iraq and Afghanistan Wars (OEF/OIF/OND). Civilians with severe TBI have increased risks of motor vehicle crashes (MVCs). Little is known about MVC risk among Veterans with TBI, many of whom incurred TBIs that were mild in severity. To examine associations between TBI and MVC-related hospitalizations among OEF/OIF/OND Veterans who use Veterans Health Administration (VA) healthcare. Using national VA data, we identified 277,330 Veterans who enrolled in VA within one year of deployment. MVC, TBI, and other diagnoses were identified using ICD-9-CM codes. We estimated risk of subsequent MVC hospitalization for those with, versus without, TBI using time-to-event analyses. Time-varying Cox proportional hazards models were used to compute hazard ratios (HR) and 95% confidence intervals (CI) while controlling for potential confounders, including psychiatric diagnoses. There were 28,551 Veterans diagnosed with TBI; 130 were subsequently hospitalized for MVC. In adjusted models, those with TBI were four times more likely to be hospitalized for MVC than those without (HR = 4.2; CI = 3.3-5.3). Veterans with TBI had substantially greater risk of MVC-related hospitalizations. These Veterans may benefit from enhanced driving safety interventions to reduce risk.

  18. Swellings of the angle of the mandible in 32 horses (1997-2011).

    PubMed

    Dixon, P M; Loh, N; Barakzai, S Z

    2014-01-01

    Disorders of the horizontal ramus (body) of the equine mandible are well reported, but there is minimal documentation of disorders of the angle of mandible. A retrospective examination of the records of Edinburgh University Equine Hospital (1997-2011) showed that 32 horses were referred due to swellings of the angle of the mandible. The aetiology of these swellings was identified in just 13/32 cases (41%) including fractures (n=2), traumatic, localised periosteal/cortical lesions (n=4), traumatic soft tissue lesions (n=2), neoplasia (n=3), and inflammation of the adjacent salivary gland (n=1) and masseter muscle (n=1). The remaining 19 (59%) cases without a definitive diagnosis showed two patterns of lesions. Twelve cases had localised periosteal/cortical lesions of the ventral aspect of the angle of mandible that were most likely traumatic in origin. The remaining seven undiagnosed cases without mandibular bony changes all had sinus tracts/chronic soft tissue infections on the medial aspect of the angle of the mandible which were believed to be caused by a draining retro-pharyngeal lesion in five cases. Surgical excision of abnormal soft tissues (if present) and bone curettage was the most successful treatment. It was concluded that the aetiology of swellings of the angle of the equine mandible are often obscure; most appear to be traumatic in origin, yet horses seldom develop gross fractures at this site due to the support of the dense surrounding musculo-tendinous structures. A smaller proportion are caused by draining retropharyngeal lesions that respond poorly to medical therapy, but respond well to surgical treatment.

  19. COAL CLEANING VIA LIQUID-FLUIDIZED CLASSIFICAITON (LFBC) WITH SELECTIVE SOLVENT SWELLING

    SciTech Connect

    J. M. Calo

    2000-12-01

    The concept of coal beneficiation due to particle segregation in water-fluidized beds, and its improvement via selective solvent-swelling of organic material-rich coal particles, was investigated in this study. Particle size distributions and their behavior were determined using image analysis techniques, and beneficiation effects were explored via measurements of the ash content of segregated particle samples collected from different height locations in a 5 cm diameter liquid-fluidized bed column (LFBC). Both acetone and phenol were found to be effective swelling agents for both Kentucky No.9 and Illinois No.6 coals, considerably increasing mean particle diameters, and shifting particle size distributions to larger sizes. Acetone was a somewhat more effective swelling solvent than phenol. The use of phenol was investigated, however, to demonstrate that low cost, waste solvents can be effective as well. For unswollen coal particles, the trend of increasing particle size from top to bottom in the LFBC was observed in all cases. Since the organic matter in the coal tends to concentrate in the smaller particles, the larger particles are typically denser. Consequently, the LFBC naturally tends to separate coal particles according to mineral matter content, both due to density and size. The data for small (40-100 {micro}m), solvent-swollen particles clearly showed improved beneficiation with respect to segregation in the water-fluidized bed than was achieved with the corresponding unswollen particles. This size range is quite similar to that used in pulverized coal combustion. The original process concept was amply demonstrated in this project. Additional work remains to be done, however, in order to develop this concept into a full-scale process.

  20. Tuning Smart Microgel Swelling and Responsive Behavior through Strong and Weak Polyelectrolyte Pair Assembly

    PubMed Central

    Costa, Eunice; Lloyd, Margaret M.; Chopko, Caroline; Aguiar-Ricardo, Ana; Hammond, Paula T.

    2012-01-01

    The layer-by-layer (LbL) assembly of polyelectrolyte pairs on temperature and pH-sensitive cross-linked poly(N-isopropylacrylamide)-co-(methacrylic acid), poly(NIPAAm-co-MAA), microgels enabled a fine tuning of the gel swelling and responsive behavior according to the mobility of the assembled polyelectrolyte (PE) pair and the composition of the outermost layer. Microbeads with well-defined morphology were initially prepared by synthesis in supercritical carbon dioxide. Upon LbL assembly of polyelectrolytes, interactions between the multilayers and the soft porous microgel led to differences in swelling and thermoresponsive behavior. For the weak PE pairs, namely poly(L-lysine) / poly(L-glutamic acid) and poly(allylamine hydrochloride) / poly(acrylic acid), polycation-terminated microgels were less swollen and more thermoresponsive than native microgel; while polyanion-terminated microgels were more swollen and not significantly responsive to temperature, in a quasi-reversible process with consecutive PE assembly. For the strong PE pair, poly(diallyldimethylammonium chloride) / poly(sodium styrene sulfonate), the differences among polycation and polyanion-terminated microgels are not sustained after the first PE bilayer due to extensive ionic cross-linking between the polyelectrolytes. The tendencies across the explored systems became less noteworthy in solutions with larger ionic strength due to overall charge shielding of the polyelectrolytes and microgel. ATR FT-IR studies correlated the swelling and responsive behavior after LbL assembly on the microgels with the extent of H-bonding and alternating charge distribution within the gel. Thus, the proposed LbL strategy may be a simple and flexible way to engineer smart microgels in terms of size, surface chemistry, overall charge and permeability. PMID:22676290

  1. Clinical correlation with failure of endovenous therapy for leg swelling.

    PubMed

    Alsheekh, Ahmad; Hingorani, Anil; Marks, Natalie; Ostrozhynskyy, Yuriy; Ascher, Enrico

    2017-06-01

    Background The development and use of minimally invasive procedures provide improved options for the management of symptoms of chronic venous insufficiency. While many patients with iliac venous occlusive disease and superficial venous insufficiency improve with combined iliac venous stenting and correction of superficial venous reflux, some patients have symptoms which persist. The goal of this study was to identify clinical factors related to persistent symptoms in patients with leg swelling after treatment of both iliac vein stenting and thermal ablation. Methods This observational study analyzed data for patients who underwent both iliac vein stent placement as well as endovenous ablation (either RFA or EVLT) as a management for chronic venous insufficiency between February 2012 and February 2014. Follow-up was performed after completion of both procedures and inquiring for improvement of swelling. Statistical analysis performed using Chi-square and student's t-test. Results Of the total 173 patients who underwent both endovenous closure and iliac vein stent placements, 55 (31.8%) patients were men; 29 (16%) patients stated they had no improvement after these procedures. The average age of patients who did not improve was 68.8 (±16.7 SD) years and 66.2 (±13.3 SD) years for patients who improved. Over all, the classification of the presenting symptoms by CEAP classification demonstrated 25.4%, 53.2%, 5.8%, and 15.6%, for C3-C6, respectively. There was no correlation with failure to improve the swelling with: age ( P = .44), gender ( P = .33), presenting symptom ( P = .67), use of calcium channel blockers ( P = .85), nitroglycerin ( P = .86), Plavix ( P = .07), aspirin ( P = .55), Synthyroid ( P = .55), Coumadin ( P = .14), angiotensin receptor blocker ( P = .81), β Blockers ( P = .61), angiotensin converting enzyme inhibitors ( P = .88), furosemide 40 mg ( P = .74), hydrochlorothiazide 12.5 mg ( P

  2. Thalamic deep brain stimulation for the treatment of tremor due to multiple sclerosis: a prospective study of tremor and quality of life.

    PubMed

    Berk, Caglar; Carr, Jason; Sinden, Marci; Martzke, Jeff; Honey, Christopher R

    2002-10-01

    In several studies a significant reduction in tremor after thalamic deep brain stimulation (DBS) has been reported among patients with multiple sclerosis (MS). It has not been determined if this results in an improved quality of life. In this study the authors prospectively evaluated the effects of thalamic DBS on tremor and quality of life. Videotapes of the patients' tremor were made preoperatively and 2 and 12 months postoperatively, and tremor was scored by a neurologist blinded to the treatment. Patients were tested pre- and postoperatively to measure any changes in their reported ability to perform selected activities of daily living and in their health-related quality of life. Patients were asked to complete a questionnaire about their satisfaction with the surgery. Postoperative changes were examined using paired t-tests. There were significant reductions in postural, action, and overall tremor at 2 and 12 months postoperatively. The patients' reported ability to feed themselves was significantly improved 2 months after surgery (p = 0.01). There were short-term trends toward improvement in reported dressing ability, personal hygiene, and writing. There were no significant changes in the SF-36 subscales or total score. In this cohort of patients with MS who suffered from tremor, thalamic DBS significantly improved their tremor and ability to feed themselves. Patient satisfaction with the procedure, however, was variable. Preoperative patient education about what functions might (and might not) be improved is crucial to avoid unrealistic expectations. Our results indicate that younger patients with MS tremor who had a shorter disease duration and no superimposed ataxia benefited most from this surgery.

  3. SAR imagery of ocean-wave swell traveling in an arbitrary direction

    NASA Technical Reports Server (NTRS)

    Rufenach, C. L.; Shuchman, R. A.; Lyzenga, D. R.

    1984-01-01

    The intensity wave like patterns observed in Synthetic Aperture Radar (SAR) are known to be caused by two mechanisms: the microwave radar cross sectional amplitude modulation due to tilt and hydrodynamic interaction of the long ocean waves, and intensity modulation due to the motion of the long ocean waves. Two dimensional closed form expressions of intensity wave patterns based on ocean wave swell are developed. They illustrate the relative importance of the amplitude and motion modulations; they also show that velocity bunching and a distortion due to the phase velocity of the ocean wave field are independent of the focus adjustment, provided that the second order temporal effects are neglected. Second order effects are small only over a limited range of ocean/radar parameters.

  4. Constraints on Pacific midplate swells from global depth-age and heat flow-age models

    NASA Astrophysics Data System (ADS)

    Stein, Carol A.; Stein, Seth

    provide no evidence for the Darwin Rise being thermally different at present from lithosphere of the same age elsewhere. The situation for the Superswell is similar to that for Hawaii, in that the heat flow data are consistent with those for unperturbed lithosphere, despite the shallow bathymetry. Flexural data for the Superswell indicate that the lithosphere was anomalously weak at the time of seamount loading. This also appears to have been the case for the Darwin Rise, but not for the Hawaiian or other swells. Although the weakness has been interpreted as due to elevated temperatures in the lithosphere, the requited high temperatures should give rise to heat flow much higher than observed. Hence the flexural strength anomaly with respect to Hawaii and other swells suggests that the lithosphere for the Superswell and Darwin Rise has been mechanically weakened by the cumulative action of multiple hot spots.

  5. Developing a swell-dependent surface roughness length for atmosphere-wave-ocean coupled models

    NASA Astrophysics Data System (ADS)

    Rutgersson, Anna; Wu, Lichuan

    2014-05-01

    When modelling the atmosphere and the ocean it is of crucial importance to correctly describe the boundary conditions. The atmospheric-ocean boundary is an important source of turbulence and there is a significant exchange of momentum, heat and moisture. The marine atmospheric boundary layer (MABL) has a considerable impact on global climate atmospheric models as 70 % of the global surface is covered with water. For regional scale models with higher resolution correctly described coupling of spheres is of particular importance in coastal regions due to the greater variability of several parameters. Surface waves can be divided into growing sea (young sea) and decaying sea (swell) with very different impact on the atmosphere. The situation with decaying sea and low wave height has in several experimental investigations been shown to give significantly lower friction at the surface as well as altered wind profiles and atmospheric turbulence. New results using data taken outside Hawaii shows that for high swell waves, wind profiles and turbulence properties are altered similarly as for low swell waves, but the surface friction is significantly enhanced (Rutgersson et al, 2010; Högström et al., 2009; 2012; Smedman et al., 2009). We use a three component regional climate modelling system to investigate the changed surface roughness description. The model covers northern Europe and model components include the atmosphere model RCA (Rossby Centre Climate model), WAM wave model and NEMO ocean model for the Baltic and North Seas. Presently the coupling is focused on introducing wave impact on the atmosphere. Sea surface roughness length is improved to take the variable swell properties into account. Roughness length is expressed in terms of the wave age and significant swell wave height. The impact of improved roughness length on surface fluxes and wind field is investigated as well as the impact on secondary parameters. Högström, U., A. Smedman, E. Sahleé, W

  6. The trumpet player with a swelling in the neck

    PubMed Central

    Edmiston, Rachel; Hariri, Ahmad; Karagama, Yakubu

    2015-01-01

    Bilateral neck swelling in patients following valsalva manouveres could lead to a diagnosis of either a pharyngocele or laryngocele. Distinguishing between them can be complicated but is vital given the possibility for an acute airway in patients with laryngoceles. A 20-year-old trumpet player presents with a 5-year history of neck swelling. Clinical suspicion is that of a pharyngocele but imaging introduces some confusion with the diagnosis. Both pharyngoceles and laryngoceles can occur as a result of prolonged positive pressure. Accurate assessment with fibreoptic examination and imaging is needed to confirm the diagnosis. Pharyngoceles are often misdiagnosed as laryngoceles. Though treatment is similar between the two patient groups it is vital that a distinction is made to enable careful observation of the airway in patients with laryngoceles. PMID:25795752

  7. Myoparasitism mimicking parotid swelling: a rare presentation of cysticercosis

    PubMed Central

    Tewari, Sandeep; Singh, Saumya; Jaiswal, Vaibhav; Mishra, Anand Kumar

    2014-01-01

    Muscular infestation with larval stage of Taenia solium is a well-recognised entity but cysticercosis of the head and neck region is a rarity. We present a case of 35-year-old young man with diffuse swelling of 3.5×4 cm in the parotid region on the right side of the face with signs of inflammation. Diagnosis was established on high-resolution ultrasonography which revealed it to be of parasitic origin. The patient was managed with antihelminthic pharmacotherapy and improved within a month. Thus cysticercosis should be considered in the differential diagnosis of subcutaneous swellings of the head and neck region, especially in endemic zones and it must be investigated well with appropriate imaging modalities so that inadvertent surgery can be avoided. PMID:24842360

  8. Hybrid composites prepared from Industrial waste: Mechanical and swelling behavior

    PubMed Central

    Ahmed, Khalil

    2013-01-01

    In this assessment, hybrid composites were prepared from the combination of industrial waste, as marble waste powder (MWP) with conventional fillers, carbon black (CB) as well as silica as reinforcing material, incorporated with natural rubber (NR). The properties studied were curing, mechanical and swelling behavior. Assimilation of CB as well as silica into MWP containing NR compound responded in decreasing the scorch time and cure time besides increasing in the torque. Additionally, increasing the CB and silica in their respective NR hybrid composite increases the tensile, tear, modulus, hardness, and cross-link density, but decreases the elongation and swelling coefficient. The degradation property e.g., thermal aging of the hybrid composite was also estimated. The overall behavior at 70 °C aging temperature signified that the replacement of MS by CB and silica improved the aging performance. PMID:25750756

  9. Swell activated chloride channel function in human neutrophils

    SciTech Connect

    Salmon, Michael D.; Ahluwalia, Jatinder

    2009-04-17

    Non-excitable cells such as neutrophil granulocytes are the archetypal inflammatory immune cell involved in critical functions of the innate immune system. The electron current generated (I{sub e}) by the neutrophil NADPH oxidase is electrogenic and rapidly depolarises the membrane potential. For continuous function of the NADPH oxidase, I{sub e} has to be balanced to preserve electroneutrality, if not; sufficient depolarisation would prevent electrons from leaving the cell and neutrophil function would be abrogated. Subsequently, the depolarisation generated by the neutrophil NADPH oxidase I{sub e} must be counteracted by ion transport. The finding that depolarisation required counter-ions to compensate electron transport was followed by the observation that chloride channels activated by swell can counteract the NADPH oxidase membrane depolarisation. In this mini review, we discuss the research findings that revealed the essential role of swell activated chloride channels in human neutrophil function.

  10. A Process to Reduce DC Ingot Butt Curl and Swell

    NASA Astrophysics Data System (ADS)

    Yu, Ho

    1980-11-01

    A simple and effective process to reduce DC ingot butt curl and swell has been developed in the Ingot Casting Division of Alcoa Technical Center.1 In the process, carbon dioxide gas is dissolved under high pressure into the ingot cooling water upstream of the mold during the first several inches of the ingot cast. As the cooling water exits from the mold, the dissolved gas evolves as micron-size bubbles, forming a temporary effective insulation layer on the ingot surface. This reduces thermal stress in the ingot butt. An insulation pad covering about 60% of the bottom block is used in conjunction with the carbon dioxide injection when maximum butt swell reduction is desired. The process, implemented in four Alcoa ingot plants, has proven extremely successful.

  11. Modeling the rapid de-swelling of toroidal hydrogels

    NASA Astrophysics Data System (ADS)

    Nikolov, Svetoslav; Chang, Ya-Wen; Alexeev, Alexander; Fernandez de Las Nieves, Alberto

    2015-03-01

    The utilization of synthetic hydrogel networks as 3-D cell culture platforms has allowed researchers to more effectively study how epigenetic factors affect cell growth and physiology. As a whole, this has emphasized the biomechanical role of scaffold structures and led to a number of advances in tissue engineering. Our current research focuses on modeling temperature activated shape transformations of toroidal poly(N-isopropylacrylamide) pNIPAM gels. We use dissipative particle dynamics (DPD) to simulate the steady (slow heating rates) and unsteady (fast heating rates) de-swelling behavior of these thermo-sensitive gels. Our simulations show that for slow heating rates the aspect ratio of the tori remains constant during de-swelling. For rapid heating rates we observe buckling instabilities. Our simulations agree with the experimental observations. Financial support by NSF CAREER Award DMR-1255288 is gratefully acknowledged.

  12. Myoparasitism mimicking parotid swelling: a rare presentation of cysticercosis.

    PubMed

    Tewari, Sandeep; Singh, Saumya; Jaiswal, Vaibhav; Mishra, Anand Kumar

    2014-05-19

    Muscular infestation with larval stage of Taenia solium is a well-recognised entity but cysticercosis of the head and neck region is a rarity. We present a case of 35-year-old young man with diffuse swelling of 3.5×4 cm in the parotid region on the right side of the face with signs of inflammation. Diagnosis was established on high-resolution ultrasonography which revealed it to be of parasitic origin. The patient was managed with antihelminthic pharmacotherapy and improved within a month. Thus cysticercosis should be considered in the differential diagnosis of subcutaneous swellings of the head and neck region, especially in endemic zones and it must be investigated well with appropriate imaging modalities so that inadvertent surgery can be avoided. 2014 BMJ Publishing Group Ltd.

  13. Persistent eyelid swelling in a patient with rosacea.

    PubMed

    Morales-Burgos, Adisbeth; Alvarez Del Manzano, Gilberto; Sánchez, Jorge L; Cruz, Carmen L

    2009-03-01

    Persistent facial swelling may occur as a rare complication of rosacea. This finding has been referred to as lymphedematous rosacea, Morbihan's disease or persistent solid facial edema. A literature review for cases of lymphedematous rosacea revealed that the chronic inflammatory process that accompanies the disease contributes to an increase in the permeability of blood vessels. With time, the lymphatic drainage system becomes permanently impaired, leading to fluid accumulation in the affected skin. Herein, we report the case of a 58-year-old female with history of rosacea who developed bilateral periorbital swelling with associated erythema of the conjunctiva (ocular rosacea) over a 4 month period that only responded to oral corticosteroids. Biopsy revealed changes of lymphedematous rosacea.

  14. Preparation and swelling inhibition of cation glucoside to montmorillonite

    NASA Astrophysics Data System (ADS)

    Song, Shaofu; Liu, Jurong; Guo, Gang; Huang, Lei; Qu, Chentun; Li, Bianqin; Chen, Gang

    2017-06-01

    In this work, a cation glucoside (CG) was synthesized with glucose and glycidyl trimethyl ammonium chloride (GTA) and used as montmorillonite (MMT) swelling inhibiter. The inhibition of CG was investigated by MMT linear expansion test and mud ball immersing test. The results showed that the CG has a good inhibition to the hydration swelling and dispersion of MMT. Under the same condition, the linear expansion rate of MMT in CG solution is much lower that of methylglucoside and the hydration expansion degree of the mud ball in the CG solution was significantly inhibited. The characterizations of physic-chemical properties of particle, analysized by thermogravimetric analysis and scanning electron microscopy, revealed that CG play great role to prevent water from absorb and keep MMT in large particle size.

  15. Swelling and drug release behavior of poly(2-hydroxyethyl methacrylate/itaconic acid) copolymeric hydrogels obtained by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Tomić, S. Lj.; Mićić, M. M.; Filipović, J. M.; Suljovrujić, E. H.

    2007-05-01

    The new copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were prepared by gamma irradiation, in order to examine the potential use of these hydrogels in controlled drug release systems. The influence of IA content in the gel on the swelling characteristics and the releasing behavior of hydrogels, and the effect of different drugs, theophylline (TPH) and fenethylline hydrochloride (FE), on the releasing behavior of P(HEMA/IA) matrix were investigated in vitro. The diffusion exponents for swelling and drug release indicate that the mechanisms of buffer uptake and drug release are governed by Fickian diffusion. The swelling kinetics and, therefore, the release rate depends on the matrix swelling degree. The drug release was faster for copolymeric hydrogels with a higher content of itaconic acid. Furthermore, the drug release for TPH as model drug was faster due to a smaller molecular size and a weaker interaction of the TPH molecules with(in) the P(HEMA/IA) copolymeric networks.

  16. Benign Cystic Mesothelioma: A Rare Cause for Scrotal Swelling

    PubMed Central

    Aber, A.; Tahir, A.; Arumuham, V.; Smith, G.; Almpanis, S.

    2012-01-01

    Benign cystic mesothelioma of the tunica vaginalis is a rare occurrence. It usually presents with painless gradual swelling in the scrotum. These types of benign mesotheliomas typically occur in the peritoneum and usually affect young to middle-aged patients. We present in this case an unusual case of benign cystic mesothelioma of the tunica vaginalis in a 77-year-old male patient. PMID:22675366

  17. SWELLING OF ERYTHROCYTES IN SOLUTIONS OF AMMONIUM SALTS

    PubMed Central

    Schiödt, E.

    1933-01-01

    Two rather simple equations have been derived, which make it possible to express in a single number the result of a series of determinations of the volume of erythrocytes swelling in solutions of ammonium salts. In all experiments made with several combinations of different concentrations of permeating and non-permeating salts, the curves calculated from the equations have covered the points found by experiment. PMID:19872754

  18. Magnetic relaxation - coal swelling, extraction, pore size. Final technical report

    SciTech Connect

    Doetschman, D.C.

    1994-10-26

    The aim of the contract was to employ electron and nuclear magnetic relaxation techniques to investigate solvent swelling of coals, solvent extraction of coals and molecular interaction with solvent coal pores. Many of these investigations have appeared in four major publications and a conference proceedings. Another manuscript has been submitted for publication. The set of Argonne Premium Coals was chosen as extensively characterized and representative samples for this project.

  19. SuperLig Ion Exchange Resin Swelling and Buoyancy Study

    SciTech Connect

    Hassan, N.M.

    2000-07-27

    The objective of this study was to achieve a fundamental understanding of SuperLig resin swelling and shrinking characteristics, which lead to channeling and early breakthrough during loading cycles. The density of salt solution that causes resin floating was also determined to establish a limit for operation. Specific tests performed include (a) pH dependence, (b) ionic strength dependence and (c) buoyancy effect vs. simulant composition.

  20. Unilateral optic disc swelling in a fighter pilot.

    PubMed

    Pokroy, Russell; Barenboim, Erez; Carter, Dan; Assa, Amit; Alhalel, Amir

    2009-10-01

    Optic disc swelling occurs when there is an obstruction to axonal transport at the level of the lamina cribrosa. This may result from compression, ischemia, inflammation, or metabolic and toxic etiologies. Some of these etiologies may be life threatening and others may be self-limited. Thus, differentiating the different etiologies is important, albeit often difficult. We present a case of a 25-yr-old high-performance fighter aviator who presented with unilateral optic disc swelling 2 d after an F-16 flight, in which decompression was suspected. Visual acuity of the affected eye was decreased to 20/25, with enlarged blind spot and shallow arcuate scotomata on visual field testing. Pupil function, brightness intensity, and color vision were normal. Marked swelling of the entire optic disc, retinal flame-shaped hemorrhages, and engorgement of the retinal veins were seen. Since decompression sickness with nitrogen bubbles obstructing the optic nerve head vasculature was suspected, he was treated with hyperbaric oxygen. He rapidly improved, recovering full vision function within 6 d. No concurrent disease was found on extensive investigation. He returned to high-performance aviation 3 mo after onset of symptoms. No recurrence was seen during 3 yr of follow-up.

  1. Quantifying Shrink Swell Capacity of Soil Using Soil Moisture Isotherms

    NASA Astrophysics Data System (ADS)

    Rivera, L. D.; Cobos, D. R.; Campbell, C. S.; Morgan, C.

    2013-12-01

    Vertisols, soils instinctively known for their expansive clays that cause them to have a high shrink swell potential, cover 2.4% of the earths ice-free land. In the United States these expansive soils can cause upwards of 6 billion in damages to pavements, foundations, and utility lines annually (Brady & Weil, 2010). Because of this, it is especially important that a soils ability to shrink and swell is well characterized when making engineering decisions. One traditional method for measuring a soil's expansive potential, the Coefficient of Linear Extensibility (COLE), can take weeks to months to complete (Grossman et al., 1968; Schafer and Singer, 1976b). Use of soil moisture isotherms, or the Soil Moisture Characteristic Curve (SMCC), in recent research has shown that the slope of the SMCC is related to a soils swelling potential (McKeen, 1992). The goal of this research is to evaluate the robustness of the relationship between the SMCC and COLE for a set of well-characterized test soils with COLE ranging from 0 to 0.176. If expansive potential can be reliably predicted from the SMCC, then data from recently developed automatic soil moisture isotherm generators could be used to characterize expansive potential with a fraction of the time and effort necessary for traditional techniques.

  2. Impurities effect on the swelling of neutron irradiated beryllium

    SciTech Connect

    Donne, M.D.; Scaffidi-Argentina, F.

    1995-09-01

    An important factor controlling the swelling behaviour of fast neutron irradiated beryllium is the impurity content which can strongly affect both the surface tension and the creep strength of this material. Being the volume swelling of the old beryllium (early sixties) systematically higher than that of the more modem one (end of the seventies), a sensitivity analysis with the aid of the computer code ANFIBE (ANalysis of Fusion Irradiated BEryllium) to investigate the effect of these material properties on the swelling behaviour of neutron irradiated beryllium has been performed. Two sets of experimental data have been selected: the first one named Western refers to quite recently produced Western beryllium, whilst the second one, named Russian refers to relatively old (early sixties) Russian beryllium containing a higher impurity rate than the Western one. The results obtained with the ANFIBE Code were assessed by comparison with experimental data and the used material properties were compared with the data available in the literature. Good agreement between calculated and measured values has been found.

  3. Dynamic mechanical and swelling properties of maleated hyaluronic acid hydrogels.

    PubMed

    Lin, Hai; Liu, Jun; Zhang, Kai; Fan, Yujiang; Zhang, Xingdong

    2015-06-05

    A series of maleated hyaluronan (MaHA) are developed by modification with maleic anhydride. The degrees of substitution (DS) of MaHA vary between 7% and 75%. The DS of MaHA is both higher and wider than methacrylated HA derivatives (MeHA) reported in the literature. MaHA hydrogels are then prepared by photopolymerization and their dynamic mechanical and swelling properties of the hydrogels are investigated. The results showed that MaHA hydrogels with moderate DS (25%, 50% and 65%) have higher storage modulus and lower equilibrium swelling ratios than those with either low or high DS (7%, 15% and 75%). Theoretical analyses also suggest a similar pattern among hydrogels with different DS. The results confirm that the increased cross-linking density enhances the strength of hydrogels. Meanwhile, the hydrophilicity of introduced groups during modification and the degree of incomplete crosslinking reaction might have negative impact on the mechanical and swelling properties of MaHA hydrogels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Bioceramic microneedles with flexible and self-swelling substrate.

    PubMed

    Cai, Bing; Xia, Wei; Bredenberg, Susanne; Li, Hao; Engqvist, Håkan

    2015-08-01

    To reduce the effort required to penetrate the skin and optimize drug release profiles, bioceramic microneedle arrays with higher-aspect-ratio needles and a flexible and self-swelling substrate have been developed. Swelling of the substrate can assist in separating it from the needles and leave them in the skin as a drug depot. The preparation procedures for this bioceramic microneedle are described in the paper. Clonidine hydrochloride, the model drug, was released in a controlled manner by the microneedle device in vitro. Results showed that the microneedle array with a flexible and self-swelling substrate released the drug content faster than the array with a rigid substrate. Disintegration of the needle material and diffusion of the drug molecules are believed as the main control mechanisms of the drug release from these microneedle arrays. Ex vivo skin penetration showed that they can effectively penetrate the stratum corneum without an extra device. This work represents a progression in the improvement of bioceramic microneedles for transdermal drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Stress-enhanced swelling of metal during irradiation

    SciTech Connect

    Garner, F.A.; Gilbert, E.R.; Porter, D.L.

    1980-04-01

    Data are available which show that stress plays a major role in the development of radiation-induced void growth in AISI 316 and many other alloys. Earlier experiments came to the opposite conclusion and are shown to have investigated stress levels which inadvertantly cold-worked the material. Stress-affected swelling spans the entire temperature range in fast reactor irradiations and accelerates with increasing irradiatin temperature. It also appears to operate in all alloy starting conditions investigated. Two major microstructural mechanisms appear to be causing the enhancement of swelling, which for tensile stresses is manifested primarily as a decrease in the incubation period. These mechanisms are stress-induced changes in the interstitial capture efficiency of voids and stress-induced changes in the vacancy emission rate of various microstructural components. There also appears to be an enhancement of intermetallic phase formation with applied stress and this is shown to increase swelling by accelerating the microchemical evolution that precedes void growth at high temperature. This latter consideration complicates the extrapolation of these data to compressive stress states.

  6. Water influx and cell swelling after nanosecond electropermeabilization.

    PubMed

    Romeo, Stefania; Wu, Yu-Hsuan; Levine, Zachary A; Gundersen, Martin A; Vernier, P Thomas

    2013-08-01

    Pulsed electric fields are used to permeabilize cell membranes in biotechnology and the clinic. Although molecular and continuum models provide compelling representations of the mechanisms underlying this phenomenon, a clear structural link between the biomolecular transformations displayed in molecular dynamics (MD) simulations and the micro- and macroscale cellular responses observed in the laboratory has not been established. In this paper, plasma membrane electropermeabilization is characterized by exposing Jurkat T lymphoblasts to pulsed electric fields less than 10ns long (including single pulse exposures), and by monitoring the resulting osmotically driven cell swelling as a function of pulse number and pulse repetition rate. In this way, we reduce the complexity of the experimental system and lay a foundation for gauging the correspondence between measured and simulated values for water and ion transport through electropermeabilized membranes. We find that a single 10MV/m pulse of 5ns duration produces measurable swelling of Jurkat T lymphoblasts in growth medium, and we estimate from the swelling kinetics the ion and water flux that follows the electropermeabilization of the membrane. From these observations we set boundaries on the net conductance of the permeabilized membrane, and we show how this is consistent with model predictions for the conductance and areal density of nanoelectropulse-induced lipid nanopores.

  7. Geophysical constraints on the compensation mechanism of the Galápagos swell

    NASA Astrophysics Data System (ADS)

    Canales, J.; Ito, G.; Detrick, R. S.; Sinton, J. M.

    2001-12-01

    We use geophysical observations such as bathymetry, gravity, and seismic crustal thickness to understand the origin of the Galápagos swell. Wide-angle refraction and multichannel reflection seismic data show that the crust along the Galápagos Spreading Center (GSC) between 97.5° W and 91° W thickens by 2.3 km as the Galápagos plume is approached from the west [Ito et al., this meeting]. Axial depth along the GSC shoals by 1800 m, 60% of which is due to dynamic topography and changes in axial morphology. The remaining 700 m correspond to the amplitude of the Galápagos bathymetric swell, 75% of which is explained by crustal thickening. The eastward shoaling of the swell and increase in crustal thickness along the GSC is accompained by a progressive decrease in mantle Bouguer gravity anomaly (MBA). Assuming a constant crustal thickness model, the MBA reaches a minimum value of -70 mGal near 91.25° W. After correcting for changes in crustal thickness, however, the gravity anomaly shows a minimum of -25 mGal near 92.2° W, the area where the GSC is intersected by the Wolf-Darwin volcanic lineament. We attribute the remaining 25% of swell bathymetry and 35% of gravity anomaly to an eastward reduction of mantle density above an effective compensation depth, constrained to be 50-200 km. Simple melting calculations assuming passive mantle upwelling predict that the observed crustal thickenning is consistent with a small eastward increase in mantle temperature of 15-25 ° C. This thermal anomaly produces an eastward decrease in mantle density due to thermal expansion and the subsequent along-axis variation in melt depletion. For preferred mantle compensation depths of 50-150 km the thermal effects can explain 40 to 70% of the mantle density anomaly required by the geophysical observations. Therefore, our results require the existence of compositionally-buoyant mantle beneath the GCS near the Galápagos plume. We will discuss plausible origins for the mantle anomaly

  8. Variations in amino acid neurotransmitters in some brain areas of adult and young male albino rats due to exposure to mobile phone radiation.

    PubMed

    Noor, N A; Mohammed, H S; Ahmed, N A; Radwan, N M

    2011-07-01

    Mobile phone radiation and health concerns have been raised, especially following the enormous increase in the use of wireless mobile telephony throughout the world. The present study aims to investigate the effect of one hour daily exposure to electromagnetic radiation (EMR) with frequency of 900 Mz (SAR 1.165 w/kg, power density 0.02 mW/cm2) on the levels of amino acid neurotransmitters in the midbrain, cerebellum and medulla of adult and young male albino rats. Adult and young rats were divided into two main groups (treated and control). The treated group of both adult and young rats was exposed to EMR for 1 hour daily. The other group of both adult and young animals was served as control. The determination of amino acid levels was carried out after 1 hour, 1 month, 2 months and 4 months of EMR exposure as well as after stopping radiation. Data of the present study showed a significant increase in both excitatory and inhibitory amino acids in the cerebellum of adult and young rats and midbrain of adult animals after 1 hour of EMR exposure. In the midbrain of adult animals, there was a significant increase in glycine level after 1 month followed by significant increase in GABA after 4 months. Young rats showed significant decreases in the midbrain excitatory amino acids. In the medulla, the equilibrium ratio percent (ER%) calculations showed a state of neurochemical inhibition after 4 months in case of adult animals, whereas in young animals, the neurochemical inhibitory state was observed after 1 month of exposure due to significant decrease in glutamate and aspartate levels. This state was converted to excitation after 4 months due to the increase in glutamate level. The present changes in amino acid concentrations may underlie the reported adverse effects of using mobile phones.

  9. The effect of pyrrolnitrin on mitochondrial reactions: the induction of swelling.

    PubMed

    Kawai, K; Shiojiri, H; Watanabe, R; Nozawa, Y

    1983-02-01

    An antifungal antibiotic, pyrrolnitrin, was found to show very similar biological activities to those of imidazole antimycotics on isolated mitochondria. Pyrrolnitrin caused drastic swelling of mitochondria in isotonic solutions of alkali metal salts and of sucrose without any addition of substrate for the respiratory chain in mitochondria. The swelling induced by pyrrolnitrin was characterized by a biphasic swelling process; a very fast initial swelling and thereafter a very slow speed secondary swelling. The increase of pyrrolnitrin concentration exponentially increased the magnitude of over-all rapid swelling. Pyrrolnitrin enhance the latent ATPase activity of mitochondria at the similar range of concentrations to those needed for the induction of the swelling. The concentrations of pyrrolnitrin where mitochondrial swelling was induced were found to be far lower than those needed for the exhibition of inhibitory effect on the electron transport system of mitochondria.

  10. The swelling-activated anion conductance in the mouse renal inner medullary collecting duct cell line mIMCD-K2.

    PubMed

    Boese, S H; Glanville, M; Gray, M A; Simmons, N L

    2000-09-01

    Swelling-activated Cl(-) currents (I(Cl,swell)) have been characterized in a mouse renal inner medullary collecting duct cell line (mIMCD-K2). Currents activated by exposing the cells to hypotonicity exhibited characteristic outward rectification and time- and voltage-dependent inactivation at positive potentials and showed an anion selectivity of I(-) > Br(-) > Cl(-) > Asp(-). NPPB (100 microm) inhibited the current in a voltage independent manner, as did exposure to 10 microm tamoxifen and 500 microm niflumic acid (NFA). In contrast, DIDS (100 microm) blocked the current with a characteristic voltage dependency. These characteristics of I(Cl, swell) in mIMCD-K2 cells are essentially identical to those of heterologously expressed cardiac CLC-3. A defining feature of CLC-3 is that activation of PKC by PDBu inhibits the conductance. In mIMCD-K2 cells preincubation with PDBu (100 nm) prevented the activation of I(Cl,swell) by hypotonicity. However, PDBu inhibition of I(Cl,swell) was reversed after PDBu withdrawal, but this was refractory to subsequent PDBu inhibition. Activation of either the cystic fibrosis transmembrane conductance regulator (CFTR) or Ca(2+) activated Cl(-) conductance (CaCC), which are coexpressed in mIMCD-K2 cells prior to PDBu treatment, abolished the PDBu inhibition of I(Cl,swell). Control of I(Cl,swell) by PKC therefore depends on the physiological status of the cell. In intact mIMCD-K2 layers in Ussing chambers, forskolin stimulation of an inward short-circuit current (due to transepithelial Cl(-) secretion via apical CFTR) was inhibited by cell swelling upon hypotonic exposure at the basolateral surface. Activation of I(Cl,swell) is therefore capable of regulating transepithelial Cl(-) secretion and suggests that I(Cl,swell) is located at the basolateral membrane. PDBu exposure prior to or during hypotonic challenge was ineffective in reversing the swelling-activated inhibition of Cl(-) secretion, but tamoxifen (100 microm) abolished the

  11. Malonate induces cell death via mitochondrial potential collapse and delayed swelling through an ROS-dependent pathway.

    PubMed

    Fernandez-Gomez, Francisco J; Galindo, Maria F; Gómez-Lázaro, Maria; Yuste, Victor J; Comella, Joan X; Aguirre, Norberto; Jordán, Joaquín

    2005-02-01

    1. Herein we study the effects of the mitochondrial complex II inhibitor malonate on its primary target, the mitochondrion. 2. Malonate induces mitochondrial potential collapse, mitochondrial swelling, cytochrome c (Cyt c) release and depletes glutathione (GSH) and nicotinamide adenine dinucleotide coenzyme (NAD(P)H) stores in brain-isolated mitochondria. 3. Although, mitochondrial potential collapse was almost immediate after malonate addition, mitochondrial swelling was not evident before 15 min of drug presence. This latter effect was blocked by cyclosporin A (CSA), Ruthenium Red (RR), magnesium, catalase, GSH and vitamin E. 4. Malonate added to SH-SY5Y cell cultures produced a marked loss of cell viability together with the release of Cyt c and depletion of GSH and NAD(P)H concentrations. All these effects were not apparent in SH-SY5Y cells overexpressing Bcl-xL. 5. When GSH concentrations were lowered with buthionine sulphoximine, cytoprotection afforded by Bcl-xL overexpression was not evident anymore. 6. Taken together, all these data suggest that malonate causes a rapid mitochondrial potential collapse and reactive oxygen species production that overwhelms mitochondrial antioxidant capacity and leads to mitochondrial swelling. Further permeability transition pore opening and the subsequent release of proapoptotic factors such as Cyt c could therefore be, at least in part, responsible for malonate-induced toxicity.

  12. [Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) associated with swelling in the brainstem: a case report].

    PubMed

    Tani, Hiroki; Nakajima, Hideto; Yamane, Kazushi; Ohnishi, Hiroyuki; Kimura, Fumiharu; Hanafusa, Toshiaki

    2014-01-01

    Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare central nervous system inflammatory disease characterized by the punctate gadolinium enhancement peppering the pons and the cerebellar peduncles as neuroimaging. We report the case of a 66-year-old woman who presented with CLIPPERS associated with swelling in the brainstem. She was hospitalized because of gait ataxia and consciousness disturbance. MRI of the brain showed FLAIR hyperintense lesions in the pons, cerebellar peduncles, cerebellum and the subcortical white matter lesion in the right occipital lobe with significant swelling in the brainstem. Diffusion-weighted MRI did not show an abnormal signal, indicating vasogenic edema. Post-contrast T1-weighted MRI showed enhanced area in the right occipital lobe and panctate gadolinium enhancement peppering brainstem. Treatment with steroids led to rapid improvement. However, she showed exacerbation of clinical and radiological findings during the tapering schedule of steroid. The biopsy from the occipital lobe revealed intense perivascular and parenchymal lymphocytic infiltrates composed of primarily T cells, B cells and macrophages. The patient was diagnosed with CLIPPERS, and treatment with increased dose of corticosteroid induced a clinical improvement. Previous reports well described a characteristic MRI finding of punctate enhancement peppering the pons. In addition, the pons and cerebellar peduncles swelling can occur in this disorder.

  13. Biochemical studies on peptide alkaloids: induction of ion selective mitochondrial swelling.

    PubMed

    Kawai, K; Nozawa, Y; Ogihara, Y

    1977-11-15

    The effect of frangulanine, a cyclopeptide alkaloid isolated from Hovenia dulcis Thunb., on mitochondrial swelling was studied. Frangulanine induced mitochondrial swelling in 0.15 M KCl solution at the concentration of 6.5 muM. The alkaloid showed ion selectivity on the induction of mitochondrial swelling. Upon addition of frangulanine, mitochondria underwent swelling in 0.15 M KCl or RbCl solution but in neither NaCl nor LiCl solution.

  14. Sexual swellings in wild white-handed gibbon females (Hylobates lar) indicate the probability of ovulation.

    PubMed

    Barelli, Claudia; Heistermann, Michael; Boesch, Christophe; Reichard, Ulrich H

    2007-02-01

    Conspicuous sexual swellings in the females of some primate species have been a focus of scientific interest since Darwin first wrote about them in 1871. To understand these visual signals, research focused on exaggerated sexual swellings of Old World primates. However, some primate species develop much smaller sexual swellings and it is as yet unclear if these smaller swellings can serve similar functions as those proposed for exaggerated swellings, i.e. advertising fertility to attract mates. We studied the temporal patterns of sexual swellings, timing of ovulation and female reproductive status in wild white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand, where this species has a variable social organization. We established fecal progestogen profiles in fifteen cycles of eight cycling females and, to detect swellings outside the menstrual cycle, five pregnant and six lactating females. In 80% of menstrual cycles, ovulation and maximum swelling phase (duration: Ø 9.3 days; 42.8% of cycle length), overlapped tightly. The probability of ovulation peaked on day 3 of the maximum swelling period. Nevertheless, the temporal relationship between maximum swelling and probability of ovulation varied from day -1 to day 13 of the swelling period and three times ovulations fell outside the maximum swelling phase. The different swellings phases occurred in similar proportions in cycling and pregnant, but not lactating females, which were rarely swollen. Despite their smaller size, gibbons' sexual swellings probably serve functions similar to those suggested for exaggerated swellings by the graded-signal hypothesis, which predicts that sexual swellings indicate the probability of ovulation, without allowing males to pinpoint its exact time.

  15. Creep and Sliding in Clay Slopes: Mutual Effects of Interlayer Swelling and Ice Jacking.

    DTIC Science & Technology

    1983-08-24

    project, swelling and freezing, have been treated as well. The extent of swell heave of the montmorillonite clay under investigation depends on the...the amount of clay size particles: up to 70% and the amount of montmorillonite : up to 35%. 1.2. Grain Size Distribution Twelve hydrometer tests were...in physical conditions and exhibit swelling again upon subsequent wetting. Another important swelling parameter is the montmorillonite content, that

  16. Swelling equilibria for cationic 2-hydroxyethyl methacrylate (HEMA)-based hydrogels

    SciTech Connect

    Baker, J.P.; Blanch, H.W.; Prausnitz, J.M.

    1993-08-01

    Cationic HEMA-based hydrogels were synthesized by copolymerizing HEMA with [(methacrylamido)propyl]trimethylammonium chloride (MAPTAC). Swelling equilibria were measured in pure water an in aqueous sodium chloride solutions. Hydrogel swelling is an increasing function of the MAPTAC content. A Flory-type swelling model using a concentration-dependent Flory {Chi} parameter semi-qualitatively describes poly(HEMA co-MAPTAC) hydrogel swelling in aqueous sodium chloride.

  17. Three-Dimensional Integration of Graphene via Swelling, Shrinking, and Adaptation.

    PubMed

    Choi, Jonghyun; Kim, Hoe Joon; Wang, Michael Cai; Leem, Juyoung; King, William P; Nam, SungWoo

    2015-07-08

    The transfer of graphene from its growth substrate to a target substrate has been widely investigated for its decisive role in subsequent device integration and performance. Thus far, various reported methods of graphene transfer have been mostly limited to planar or curvilinear surfaces due to the challenges associated with fractures from local stress during transfer onto three-dimensional (3D) microstructured surfaces. Here, we report a robust approach to integrate graphene onto 3D microstructured surfaces while maintaining the structural integrity of graphene, where the out-of-plane dimensions of the 3D features vary from 3.5 to 50 μm. We utilized three sequential steps: (1) substrate swelling, (2) shrinking, and (3) adaptation, in order to achieve damage-free, large area integration of graphene on 3D microstructures. Detailed scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and electrical resistance measurement studies show that the amount of substrate swelling as well as the flexural rigidities of the transfer film affect the integration yield and quality of the integrated graphene. We also demonstrate the versatility of our approach by extension to a variety of 3D microstructured geometries. Lastly, we show the integration of hybrid structures of graphene decorated with gold nanoparticles onto 3D microstructure substrates, demonstrating the compatibility of our integration method with other hybrid nanomaterials. We believe that the versatile, damage-free integration method based on swelling, shrinking, and adaptation will pave the way for 3D integration of two-dimensional (2D) materials and expand potential applications of graphene and 2D materials in the future.

  18. Segmental heterogeneity of swelling-induced Cl- transport in rat small intestine.

    PubMed

    Diener, M; Bertog, M; Fromm, M; Scharrer, E

    1996-06-01

    The effect of cell swelling induced by hypotonic media was studied in segments of rat small intestine. In the Ussing chamber, exposure to a hypotonic medium caused a decrease in short-circuit current (Isc) and potential difference (Vms) in the jejunum, whereas the ileum responded with an increase in Isc and Vms. The transition from one pattern to the other was located about in the middle of the small intestine. Tissue conductance decreased in both segments, probably due to a reduction of paracellular shunt conductance induced by the cell swelling. Voltage scanning experiments revealed that the observed decrease in total tissue conductance in the ileum was caused solely by a decrease in local conductance in the villus region while the crypt conductance did not change, suggesting that the decrease in paracellular conductance of the crypts is compensated by an increase in cellular conductance. The response in both segments was dependent on the presence of Cl- and was blocked by the Cl- channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB). It was not affected by the neurotoxin tetrodotoxin. In the jejunum the swelling-induced decrease in Isc was reduced in the presence of the cyclooxygenase inhibitor, indomethacin, or the lipoxygenase inhibitor, nordihydroguaiaretic acid. In the ileum the Cl- secretion induced by hypotonicity was blocked by the K+ channel blocker quinine and was reversed into a decrease in Isc when serosal Ca2+ was zero. We conclude that the observed volume regulatory changes are initiated in the jejunum by an eicosanoid-mediated opening of basolateral Cl- channels and in the ileum by a Ca2+-mediated opening of K+ channels which enhances apical Cl- efflux.

  19. Neutron Diffraction of Aqueous Tetramethylammonium Chloride (TMA) Solutions and TMA Intercalated Swelling Clays Under Burial Conditions

    NASA Astrophysics Data System (ADS)

    Patel, R.; Howard, C. A.; Greenwell, C.; Youngs, T.; Soper, A. K.; Skipper, N. T.

    2014-12-01

    There is a need for the improvement and optimisation of clay swelling inhibitors for the enhancement of oil and gas exploration. The hydration region of both ions and the possibility of ion pairing in 1 molar aqueous solution of clay swelling inhibitor, tetramethylammonium chloride (TMACl), in D2O, under elevated hydrostatic-pressures and temperatures has been determined with unprecedented detail using a combination of neutron diffraction and small-angle scattering in conjunction with hydrogen/deuterium isotopic labeling. The O-H correlation function (H-bonds) for the water in the 1.0M solution is measured and compared with that for pure D2O. Also investigated is the effect of burial conditions on the d-spacing of TMA-intercalated vermiculite. Contrary to expectations, no aggregation of TMA ions due to hydrophobic interactions is observed, nor are any ionic pairs of TMA+ and Cl- at these burial conditions. The data revealed a more ordered water-water structure with the addition of TMACl from bulk D2O. There is no change in the hydration structure measured at the applied elevated conditions. This is in remarkable contrast to pure water at the same conditions which is well known to be compressible. The dry d-spacing of the TMA-exchanged Eucatex vermiculite is measured at 13.66 Å which increases to 14.03 Å with the addition of D2O. Beyond this, there is no change in d-spacing with increasing pressure and temperature indicating the strength of the TMA ions binding to the clay interlayers and therefore its performance as a clay-swelling inhibitor.

  20. Flakeboard thickness swelling. Part II, Fundamental response of board properties to steam injection pressing

    Treesearch

    Robert L. Geimer; Jin Heon. Kwon

    1999-01-01

    The results of this study showed that the same relative reductions in thickness swelling (TS) previously obtained with steam-injection-pressed (SIP) resinless mats are also obtained in boards bonded with 3% isocyanate resin. Reductions in thickness swelling were proportional to steam time and pressure. Thickness swelling of 40% measured in conventionally pressed boards...

  1. Nail swelling as a pre-formulation screen for the selection and optimisation of ungual penetration enhancers.

    PubMed

    Khengar, R H; Jones, S A; Turner, R B; Forbes, B; Brown, M B

    2007-12-01

    Targeting drug treatment to fungal infections that reside within or below the nail plate is problematic due to the highly restrictive barrier of the human nail. To optimise topical formulations for ungual drug delivery, inclusion of an effective penetration enhancer (PE) is imperative. At present, in vitro nail permeation studies can take weeks or months in order to obtain any meaningful data because the lack of a simple in vitro model to identify and develop nail PEs makes the selection and optimisation of novel PEs an empirical and inefficient process. The aim of this study was to compare three methods for pre-formulation screening of putative ungual PEs and then to select the most suitable technique for screening candidates that may enhance the permeation of therapeutic agents through the human nail. Three screening techniques were evaluated; nail swelling (weight increase of human nail clippings), horse hoof swelling (weight increase of horse hoof clippings) and nail penetration of a radiolabelled permeability probe. Four test PEs were evaluated using each screening method and nail swelling was identified as a simple, rapid, economic, relevant and reliable technique. This screen was then used to evaluate 20 potential PEs. Thioglycolic acid (TA), hydrogen peroxide (H(2)O(2)) and urea H(2)O(2) produced the greatest nail weight increases; 71.0+/-4.6%, 69.2+/-6.6%, and 69.0+/-9.9 respectively. To confirm the relationship between human nail swelling and altered ungual barrier function, a permeation study was performed in human nails using caffeine as a model penetrant. Human nails pre-treated with TA in vitro had a 3.8-fold increase in caffeine flux compared to the control (TA-free solution). This study illustrated the potential to use human nail clipping swelling as a surrogate marker of PE activity for topical ungual drug delivery.

  2. Linking natural microstructures with numerical modeling of pinch-and-swell structures

    NASA Astrophysics Data System (ADS)

    Peters, Max; Berger, Alfons; Herwegh, Marco; Regenauer-Lieb, Klaus

    2016-04-01

    dominated deformation at relatively high extensional strains in the pinches. The numerical simulations indicate that viscosity weakening due to dissipated heat from grain size reduction marks the onset of localization, resulting in continuous necking of the layer. Interestingly, there exist multiple steady states, i.e. a first homogeneous state out of which localization arises, steady states of the stable end-member structure, expressed by homogeneous conditions in both pinches and swells, and in the surrounding matrix, the latter obeying a linear rheology. Based on our microstructural and numerical results, we suggest that the onset of localization represents a fundamental material bifurcation. This implies that the studied structures can be described as ductile instabilities. Finally, we discuss the profound role of the energy theory of localization described here, which allows deriving the paleo-deformation conditions, as well as fundamental material properties in a self-consistent manner. REFERENCES Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (2014): Journal of Geophysical Research 119, doi:10.1002/2013JB010701 Peters, M., Veveakis, M., Poulet, T., Karrech, A., Herwegh, M. and Regenauer-Lieb, K. (2015): Journal of Structural Geology 78, doi:10.1016/j.jsg.2015.06.005

  3. Water Migration and Swelling in Bentonite Quantified using Neutron Radiography

    NASA Astrophysics Data System (ADS)

    Vial, A.; DiStefano, V. H.; Perfect, E.; Hale, R. E.; Anovitz, L. M.; McFarlane, J.

    2016-12-01

    Permanent disposal of radioactive waste remains a critical challenge for the nation's energy future. All disposal system concepts include interfaces between engineered systems and natural materials requiring extensive characterization. Bentonite is often used to buffer subsurface disposal systems from geologic media containing ground water. Bentonite characterization experiments were carried out using the CG-1D neutron imaging beam line at Oak Ridge National Laboratory. Dry bentonite was packed into vertically-oriented aluminum cylinders. Water was ponded on the top surface of each packed cylinder. Images were acquired at 2 min intervals using dynamic neutron radiography. The detector consisted of stacked neutron sensitive microchannel plates above a quad Timepix readout with a 28 x 28 mm2 field of view. The spatial resolution of the detector was 55 μm. Raw neutron radiographs were imported into ImageJ and normalized with respect to the initial completely dry state. The wetting process was 1-dimensional, and vertical intensity profiles were computed by averaging pixel rows. The vertical distance between the clay-water interface and the wetting front could then be determined as a function of time. Depth of water infiltration increased linearly with the square root of time, yielding a sorptivity value of 0.75 (± 0.070) mm/min0.5. Swelling occurred in the form of upward movement of clay particles into the ponded water over time. The resulting low density assemblage was discernable by normalizing the raw profiles with respect to the intensity profile immediately after ponding. The packed clay-water interface was clearly visible in the normalized profiles, and swelling was quantified as the height of the low density assemblage above the original interface. Swelling occurred as a linear function of time, at a rate of 0.054 (± 0.020) mm/min. Further experiments of this type are planned under variable temperature and pressure regimes applicable to subsurface

  4. On sorption and swelling of CO2 in clays

    DOE PAGES

    Busch, A.; Bertier, P.; Gensterblum, Y.; ...

    2016-03-23

    One well-studied technology is the geological storage of carbon dioxide (CO2), and a number of demonstration projects around the world have proven its feasibility and challenges. Storage conformance and seal integrity are among the most important aspects, as they determine risk of leakage as well as limits for storage capacity and injectivity. By providing evidence for safe storage is critical for improving public acceptance. Most caprocks are composed of clays as dominant mineral type which can typically be illite, kaolinite, chlorite or smectite. A number of recent studies addressed the interaction between CO2 and these different clays and it wasmore » shown that clay minerals adsorb considerable quantities of CO2. For smectite this uptake can lead to volumetric expansion followed by the generation of swelling pressures. On the one hand CO2 adsorption traps CO2, on the other hand swelling pressures can potentially change local stress regimes and in unfavourable situations shear-type failure is assumed to occur. Moreover, for storage in a reservoir having high clay contents the CO2 uptake can add to storage capacity which is widely underestimated so far. Smectite-rich seals in direct contact with a dry CO2 plume at the interface to the reservoir might dehydrate leading to dehydration cracks. Such dehydration cracks can provide pathways for CO2 ingress and further accelerate dewatering and penetration of the seal by supercritical CO2. At the same time, swelling may also lead to the closure of fractures or the reduction of fracture apertures, thereby improving seal integrity. Finally, the goal of this communication is to theoretically evaluate and discuss these scenarios in greater detail in terms of phenomenological mechanisms, but also in terms of potential risks or benefits for carbon storage.« less

  5. Swelling of the vesicle is prerequisite for PTH secretion.

    PubMed

    Lim, S K; Kwon, Y H; Song, Y D; Lee, H C; Ryu, K J; Huh, K B; Park, C S

    1996-02-01

    Unlike most secretory cells, high extra cellular calcium inhibits rather than stimulates hormonal secretion in several cells such as parathyroid cells, Juxtaglomerular cells and osteoclast. To gain further insight into the common but unique stimulus-secretion coupling mechanism in these cells, bovine parathyroid slices were incubated in various conditions of Krebs-Ringer (KR) solution containing essential amino acids. Parathyroid cells showed the inverse dependency of secretion on extra cellular calcium concentration as we expected. Ammonium acetate overcame the inhibitory effect of 2.5 mM of calcium and the maximum effect was as much as the five times of the basal value, while there was a little additive effect under 0 mM CaCl2. PTH secretion was biphasic according to the change of extra cellular osmolarity and the lowest response was observed at 300 mOsm/l. In Na-rich KR solution, high concentration of nigericin (> 10(-4)M) completely overcame the inhibitory effect of 2.5 mM CaCl2 and the maximum stimulatory effect was 8 times greater whereas it was only 2 times greater without CaCl2. In K-rich KR solution that abolished the K-gradient between the extra cellular solution and the cytoplasm, the rate of PTH secretion increased, and furthermore the addition of nigericin increased the rate of secretion significantly. The results above suggested that the osmotic swelling of the secretory vesicle in parathyroid cells might promote exocytosis as in Juxtaglomerular cells. We propose that the swelling of the vesicle is also prerequisite for secretion in several cells inhibited paradoxically by Ca++, whatever the signal transduction pathway for swelling of the secretory granules induced by the lowering of Ca++ in cytoplasm are.

  6. Generalized Rate Theory for Void and Bubble Swelling and its Application to Plutonium Metal Alloys

    SciTech Connect

    Allen, P. G.; Wolfer, W. G.

    2015-10-16

    In the classical rate theory for void swelling, vacancies and self-interstitials are produced by radiation in equal numbers, and in addition, thermal vacancies are also generated at the sinks, primarily at edge dislocations, at voids, and at grain boundaries. In contrast, due to the high formation energy of self-interstitials for normal metals and alloys, their thermal generation is negligible, as pointed out by Bullough and Perrin [1]. However, recent DFT calculations of the formation energy of self-interstitial atoms in bcc metals [2,3] have revealed that the sum of formation and migration energies for self-interstitials atoms (SIA) is of the same order of magnitude as for vacancies. This is illustrated in Fig. 1 that shows the ratio of the activation energies for thermal generation of SIA and vacancies. For fcc metals, this ratio is around three, but for bcc metals it is around 1.5. Reviewing theoretical predictions of point defect properties in δ-Pu [4], this ratio could possibly be less than one. As a result, thermal generation of SIA in bcc metals and in plutonium must be taken into considerations when modeling the growth of voids and of helium bubbles, and the classical rate theory (CRT) for void and bubble swelling must be extended to a generalized rate theory (GRT).

  7. [Painless orbital swelling after sojourn in tropics. Cysticercosis and other parasitic eye diseases].

    PubMed

    Wabbels, B; Kruse, F; Helmke, B; Rohrschneider, K; Völcker, H E

    2000-08-01

    The differential diagnosis of painless orbital swelling is complex and based on radiological and physical examination as well as laboratory tests. Due to increasing tourism to exotic countries a thorough history is important to observe diseases which are rare in industrialised countries but frequent in developing countries. A 30-year-old man complained about a painless orbital swelling in the absence of general symptoms. Orbital examination revealed a normal globe. MRI scan and B-scan ultrasounds showed an orbital cyst with a diameter of 1 cm. The patient's history disclosed lengthy travel to India as well as South East Asia. Histopathological examinations following excision of a whitish intraorbital mass showed a cream-white, thin walled cyst with a single central invaginated scolex with suckers and hooklets. This finding is characteristic for cysticercosis. Cysticercus cellulose is the larval stage of the pork tapeworm Taenia solium. It is transmitted by ingestion of contaminated food or water. Ocular affection is reported concerning the vitreous or subretinal localisation, less often in the anterior segment, subconjunctiva or orbita. Especially after trips to tropical regions, parasitic diseases should be kept in mind when dealing with unusual eye symptoms. Besides cysticercosis there are e.g. echinococcosis, onchocercosis (river blindness) and infections with toxocara or Loa loa.

  8. Revealing nanocomposite filler structures by swelling and small-angle X-ray scattering.

    PubMed

    Baeza, Guilhem P; Genix, Anne-Caroline; Paupy-Peyronnet, Nathalie; Degrandcourt, Christophe; Couty, Marc; Oberdisse, Julian

    2016-01-01

    Polymer nanocomposites are used widely, mainly for the industrial application of car tyres. The rheological behavior of such nanocomposites depends in a crucial way on the dispersion of the hard filler particles - typically silica nanoparticles embedded in a soft polymer matrix. It is thus important to assess the filler structure, which may be quite difficult for aggregates of nanoparticles of high polydispersity, and with strong interactions at high loading. This has been achieved recently using a coupled TEM/SAXS structural model describing the filler microstructure of simplified industrial nanocomposites with grafted or ungrafted silica of high structural disorder. Here, we present an original method capable of reducing inter-aggregate interactions by swelling of nanocomposites, diluting the filler to low-volume fractions. Note that this is impossible to reach by solid mixing due to the large differences in viscoelasticity between the composite and the pure polymer. By combining matrix crosslinking, swelling in a good monomer solvent, and post-polymerization of these monomers, it is shown that it is possible to separate the filler into small aggregates. The latter have then been characterized by electron microscopy and small-angle X-ray scattering, confirming the conclusions of the above mentioned TEM-SAXS structural model applied directly to the highly loaded cases.

  9. Impact of glissile interstitial loop production in cascades on void ordering and swelling saturation under irradiation

    NASA Astrophysics Data System (ADS)

    Dubinko, V. I.

    1995-08-01

    According to the dislocation model of void ordering and swelling saturation by the present author, these phenomena arise due to the absorption by voids of perfect glissile dislocation loops produced by irradiation. The formation and glide of small interstitial loops has been also confirmed by recent molecular dynamics (MD) studies of displacement cascades. The cascade mechanism of the loop production is shown to explain an absence of visible dislocation loops in some experiments on void lattices, which is a very important argument in favor of the present theory. However, according to the MD simulations, the glide of such loops seems not to depend on the stacking fault energy of the host lattice, contrary to the predictions of the elastic continuum theory. The latter shows that high stacking energy (as in most bcc metals and in fcc Ni and Al) favors the unfaulting of small loops, which seems to be in agreement with experimentally observed void lattice formation in these metals as compared to the resistance of the low stacking energy metals (such as Cu, Ag, Au and most steels) to void lattice formation. This discrepancy between continuum theory and MD simulations shows the need for further studies of displacement cascades, in particular, in more complex systems modeling the effects of impurities on the nature of interstitial clusters. An outstanding problem is to find impurities that can facilitate the unfaulting process and, hence, void ordering and swelling saturation in those fcc metals which are currently supposed to be void lattice resistant.

  10. Teaching ocean wave forecasting using computer-generated visualization and animation—Part 2: swell forecasting

    NASA Astrophysics Data System (ADS)

    Whitford, Dennis J.

    2002-05-01

    This paper, the second of a two-part series, introduces undergraduate students to ocean wave forecasting using interacti