When is acute persistent cough in school-age children and adults whooping cough?

PubMed Central

Philipson, Kathryn; Goodyear-Smith, Felicity; Grant, Cameron C; Chong, Angela; Turner, Nikki; Stewart, Joanna

2013-01-01

Background Pertussis is a vaccine modified disease in most age groups and hence subtle in its presentation. Current diagnostic approaches require relatively invasive sampling. Aim To determine the incidence of B. pertussis infection among people aged 5–49 years identified in primary care with acute persistent cough using an oral fluid based diagnostic test. Design and setting Active surveillance of acute persistent cough of 2 weeks duration or greater was established in Auckland, New Zealand from May to October 2011. The 15 participating primary care practices provided care for a socioeconomically diverse population. Method Recent B. pertussis infection was determined by measurement of IgG antibodies to pertussis toxin (PT) in an oral fluid sample. An IgG antibody titre to PT of ≥70 arbitrary units defined recent infection. Participants reported symptoms at presentation and kept a cough diary. Results A total of 226 participants were enrolled: 70 (31%) were children (5–16 years) and 156 (69%) were adults (17–49 years). Oral fluid samples were obtained from 225 participants. Ten per cent (23/225) had recent B. pertussis infection including a larger proportion of children than adults (17% versus 7%, P = 0.003). Neither cough duration nor any individual symptom discriminated between those with and without recent B. pertussis infection. Conclusion Pertussis is a frequent cause of acute persistent cough presenting to primary care. Clinical differentiation of pertussis from other causes of acute persistent cough is difficult. An oral fluid based diagnostic test, which is less invasive than other diagnostic approaches, has high acceptability in primary care. PMID:23972198

Resurgence of Ebola Virus Disease in Guinea Linked to a Survivor With Virus Persistence in Seminal Fluid for More Than 500 Days.

PubMed

Diallo, Boubacar; Sissoko, Daouda; Loman, Nicholas J; Bah, Hadja Aïssatou; Bah, Hawa; Worrell, Mary Claire; Conde, Lya Saidou; Sacko, Ramata; Mesfin, Samuel; Loua, Angelo; Kalonda, Jacques Katomba; Erondu, Ngozi A; Dahl, Benjamin A; Handrick, Susann; Goodfellow, Ian; Meredith, Luke W; Cotten, Matthew; Jah, Umaru; Guetiya Wadoum, Raoul Emeric; Rollin, Pierre; Magassouba, N'Faly; Malvy, Denis; Anglaret, Xavier; Carroll, Miles W; Aylward, Raymond Bruce; Djingarey, Mamoudou Harouna; Diarra, Abdoulaye; Formenty, Pierre; Keïta, Sakoba; Günther, Stephan; Rambaut, Andrew; Duraffour, Sophie

2016-11-15

We report on an Ebola virus disease (EVD) survivor who showed Ebola virus in seminal fluid 531 days after onset of disease. The persisting virus was sexually transmitted in February 2016, about 470 days after onset of symptoms, and caused a new cluster of EVD in Guinea and Liberia. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

Ebola Virus Persistence in Ocular Tissues and Fluids (EVICT) Study: Reverse Transcription-Polymerase Chain Reaction and Cataract Surgery Outcomes of Ebola Survivors in Sierra Leone.

PubMed

Shantha, Jessica G; Mattia, John G; Goba, Augustine; Barnes, Kayla G; Ebrahim, Faiqa K; Kraft, Colleen S; Hayek, Brent R; Hartnett, Jessica N; Shaffer, Jeffrey G; Schieffelin, John S; Sandi, John D; Momoh, Mambu; Jalloh, Simbirie; Grant, Donald S; Dierberg, Kerry; Chang, Joyce; Mishra, Sharmistha; Chan, Adrienne K; Fowler, Rob; O'Dempsey, Tim; Kaluma, Erick; Hendricks, Taylor; Reiners, Roger; Reiners, Melanie; Gess, Lowell A; ONeill, Kwame; Kamara, Sarian; Wurie, Alie; Mansaray, Mohamed; Acharya, Nisha R; Liu, William J; Bavari, Sina; Palacios, Gustavo; Teshome, Moges; Crozier, Ian; Farmer, Paul E; Uyeki, Timothy M; Bausch, Daniel G; Garry, Robert F; Vandy, Matthew J; Yeh, Steven

2018-04-01

Ebola virus disease (EVD) survivors are at risk for uveitis during convalescence. Vision loss has been observed following uveitis due to cataracts. Since Ebola virus (EBOV) may persist in the ocular fluid of EVD survivors for an unknown duration, there are questions about the safety and feasibility of vision restorative cataract surgery in EVD survivors. We conducted a cross-sectional study of EVD survivors anticipating cataract surgery and patients with active uveitis to evaluate EBOV RNA persistence in ocular fluid, as well as vision outcomes post cataract surgery. Patients with aqueous humor that tested negative for EBOV RNA were eligible to proceed with manual small incision cataract surgery (MSICS). We screened 137 EVD survivors from June 2016 - August 2017 for enrolment. We enrolled 50 EVD survivors; 46 with visually significant cataract, 1 with a subluxated lens, 2 with active uveitis and 1 with a blind painful eye due to uveitis. The median age was 24.0years (IQR 17-35) and 35 patients (70%) were female. The median logMAR visual acuity (VA) was 3.0 (Snellen VA Hand motions; Interquartile Range, IQR: 1.2-3.0, Snellen VA 20/320 - Hand motions). All patients tested negative for EBOV RNA by RT-PCR in aqueous humor/vitreous fluid and conjunctiva at a median of 19months (IQR 18-20) from EVD diagnosis in Phase 1 of ocular fluid sampling and 34months (IQR 32-36) from EVD diagnosis in Phase 2 of ocular fluid sampling. Thirty-four patients underwent MSICS, with a preoperative median VA improvement from hand motions to 20/30 at three-month postoperative follow-up (P<0.001). EBOV persistence by RT-PCR was not identified in ocular fluid or conjunctivae of fifty EVD survivors with ocular disease. Cataract surgery can be performed safely with vision restorative outcomes in patients who test negative for EBOV RNA in ocular fluid specimens. These findings impact the thousands of West African EVD survivors at-risk for ocular complications who may also require eye surgery during EVD convalescence. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Localized structures in vibrated emulsions

NASA Astrophysics Data System (ADS)

Falcón, Claudio; Bruggeman, Jake; Pasquali, Matteo; Deegan, Robert D.

2012-04-01

We report our observations of localized structures in a thin layer of an emulsion subjected to vertical oscillations. We observe persistent holes, which are voids that span the layer depth, and kinks, which are fronts between regions with and without fluid. These structures form in response to a finite amplitude perturbation. Combining experimental and rheological measurements, we argue that the ability of these structures to withstand the hydrostatic pressure of the surrounding fluid is due to convection within their rim. For persistent holes the oscillatory component of the convection generates a normal stress which opposes contraction, while for kinks the steady component of the convection generates a shear stress which opposes the hydrostatic stress of the surrounding fluid.

A pilot study: The effects of repeat washing and fabric type on the detection of seminal fluid and spermatozoa.

PubMed

Nolan, A; Speers, Samuel J; Murakami, Julie; Chapman, Brendan

2018-05-19

In sexual assault cases and more specifically those involving childhood sexual abuse (CSA), victims may have had their potentially semen-stained clothing washed multiple times before a criminal investigation commences. Although it has been previously demonstrated that spermatozoa persist on cotton clothing following a single wash cycle, items of clothing washed multiple times are not routinely examined in these cases because of the assumption that the laundering process would have removed all seminal fluid and spermatozoa. The aim of this study was to examine the persistence of seminal fluid and spermatozoa on a range of fabric types including cotton, nylon, terry towel (100% cotton), polyester fleece, satin and lace which were laundered up to six times. Three techniques were used for the detection of seminal fluid and spermatozoa: an alternative light source, acid phosphatase test and microscopy. The study demonstrated that spermatozoa persisted on cotton and terry towel following six wash cycles. This data emphasises the need to recover and examine items of clothing and bedding of victims for semen, even if the item has been washed multiple times. Copyright © 2018 Elsevier B.V. All rights reserved.

Spectral-domain optical coherence tomography analysis of persistent subretinal fluid after scleral buckling surgery for macula-off retinal detachment

PubMed Central

Gharbiya, M; Malagola, R; Mariotti, C; Parisi, F; De Vico, U; Ganino, C; Grandinetti, F

2015-01-01

Purpose To determine the predictive value of markers for persistent subretinal fluid (SRF) absorption and the influence of subfoveal fluid on visual outcome after scleral buckle (SB) surgery for rhegmatogenous retinal detachment (RRD). Patients and methods This was a retrospective, observational study. We reviewed the medical records of 64 eyes of 64 patients who underwent SB surgery for macula-off RRD. Patients underwent clinical examination and spectral-domain optical coherence tomography before surgery, at 1 month and every 3 months postoperatively. The height and width of SRF bleb(s) were measured over time. Results Persistent SRF at 1 month was observed in 40 eyes (62.5%). SRF blebs were first detected 1.7±2.2 months postoperatively. In 29 cases that could be fully followed up, SRF blebs were completely absorbed 7.8±4.4 months postoperatively. Resolution of fluid was associated with an improvement of VA (P=0.003). Serial measurements of SRF bleb size showed that bleb width decreased significantly at all time points during the 12-month follow-up period (P<0.05), while significant bleb height decrease occurred from postoperative sixth month only (P<0.05). There was no correlation between VA outcomes and subfoveal bleb height or width (P>0.05). The cut-off value of the bleb width-to-height ratio level for predicting bleb absorption at 6 months was 7, with 89% sensitivity and 83% specificity. Conclusions Visual improvement may occur with late resolution of residual subfoveal fluid. A bleb width-to-height ratio >7 indicates a higher risk of SRF to persist beyond 6 months after surgery. PMID:26139048

Comparison of Detection of Bovine Virus Diarrhea Virus Antigen in Various Types of Tissue and Fluid Samples Collected from Persistently Infected Cattle

USDA-ARS?s Scientific Manuscript database

Bovine viral diarrhea viruses are economically important pathogens of cattle. Most new infections are acquired from animals persistently infected with the virus. Surveillance programs rely on skin biopsies for detection of persistently infected cattle. The purpose of this study was to compare ant...

Topological patterns of mesh textures in serpentinites

NASA Astrophysics Data System (ADS)

Miyazawa, M.; Suzuki, A.; Shimizu, H.; Okamoto, A.; Hiraoka, Y.; Obayashi, I.; Tsuji, T.; Ito, T.

2017-12-01

Serpentinization is a hydration process that forms serpentine minerals and magnetite within the oceanic lithosphere. Microfractures crosscut these minerals during the reactions, and the structures look like mesh textures. It has been known that the patterns of microfractures and the system evolutions are affected by the hydration reaction and fluid transport in fractures and within matrices. This study aims at quantifying the topological patterns of the mesh textures and understanding possible conditions of fluid transport and reaction during serpentinization in the oceanic lithosphere. Two-dimensional simulation by the distinct element method (DEM) generates fracture patterns due to serpentinization. The microfracture patterns are evaluated by persistent homology, which measures features of connected components of a topological space and encodes multi-scale topological features in the persistence diagrams. The persistence diagrams of the different mesh textures are evaluated by principal component analysis to bring out the strong patterns of persistence diagrams. This approach help extract feature values of fracture patterns from high-dimensional and complex datasets.

Role of amnioinfusion in the management of premature rupture of the membranes at <26 weeks' gestation.

PubMed

Locatelli, A; Vergani, P; Di Pirro, G; Doria, V; Biffi, A; Ghidini, A

2000-10-01

We sought to evaluate whether serial amnioinfusions for persistent oligohydramnios can affect the perinatal and long-term outcomes in extreme cases of preterm premature rupture of membranes. All singleton pregnancies with preterm premature rupture of membranes at <26 weeks' gestation and lasting >4 days between January 1991 and June 1998 were included. Amniotic fluid volume was assessed as the maximum cord-free pocket with serial ultrasonographic examinations. Consenting women with persistent (>4 days) oligohydramnios (amniotic fluid 2 cm. The pregnancy, neonatal, and long-term neurologic outcomes of the cases that spontaneously maintained a median amniotic fluid pocket >2 cm (amnioinfusion-not-necessary group) were compared with those of women with oligohydramnios who underwent amnioinfusion but continued to have a median amniotic fluid pocket after preterm premature rupture of membranes 2 cm for >/=48 hours in 11 (30%) patients. This successful amnioinfusion group was comparable with the persistent oligohydramnios group (n = 25) in gestational age at first amnioinfusion (median, 20.2 weeks; range, 16-25.6 weeks; vs median, 20.3 weeks; range, 16.5-24.2 weeks; P =.4), number of amnioinfusions (median, 3; range, 1-9; vs median, 3; range, 1-5; P =.4), and interval between amnioinfusions (median, 6 days; range, 4-14 days; vs median, 8 days; range, 6-43 days; P =. 1). However, patients in the persistent oligohydramnios group had a significantly shorter interval to delivery, lower neonatal survival (20%), and higher rates of pulmonary hypoplasia (62%) and abnormal neurologic outcomes (60%) than the patients in the groups in which amnioinfusion was not necessary or was successful (all P

Diagnosis Of Persistent Infection In Prosthetic Two-Stage Exchange: PCR analysis of Sonication fluid From Bone Cement Spacers.

PubMed

Mariaux, Sandrine; Tafin, Ulrika Furustrand; Borens, Olivier

2017-01-01

Introduction: When treating periprosthetic joint infections with a two-stage procedure, antibiotic-impregnated spacers are used in the interval between removal of prosthesis and reimplantation. According to our experience, cultures of sonicated spacers are most often negative. The objective of our study was to investigate whether PCR analysis would improve the detection of bacteria in the spacer sonication fluid. Methods: A prospective monocentric study was performed from September 2014 to January 2016. Inclusion criteria were two-stage procedure for prosthetic infection and agreement of the patient to participate in the study. Beside tissues samples and sonication, broad range bacterial PCRs, specific S. aureus PCRs and Unyvero-multiplex PCRs were performed on the sonicated spacer fluid. Results: 30 patients were identified (15 hip, 14 knee and 1 ankle replacements). At reimplantation, cultures of tissue samples and spacer sonication fluid were all negative. Broad range PCRs were all negative. Specific S. aureus PCRs were positive in 5 cases. We had two persistent infections and four cases of infection recurrence were observed, with bacteria different than for the initial infection in three cases. Conclusion: The three different types of PCRs did not detect any bacteria in spacer sonication fluid that was culture-negative. In our study, PCR did not improve the bacterial detection and did not help to predict whether the patient will present a persistent or recurrent infection. Prosthetic 2-stage exchange with short interval and antibiotic-impregnated spacer is an efficient treatment to eradicate infection as both culture- and molecular-based methods were unable to detect bacteria in spacer sonication fluid after reimplantation.

A 3D Hydrodynamic Model for Heterogeneous Biofilms with Antimicrobial Persistence

DTIC Science & Technology

2014-01-01

antimicrobial agents, providing a useful tool for analyzing the mechanism of biofilm persistence to antimicrobial agents in an aqueous environment. The numerical...mecha- nism of biofilm persistence to antimicrobial agents in an aqueous environment. The numerical result also confirms that the periodic dosing...We model the biofilm together with its surrounding aqueous environment as a mixture of complex fluids. The biofilm is consisted of the biomass

Premature rupture of the membranes at <26 weeks' gestation: role of amnioinfusion in the management of oligohydramnios.

PubMed

Vergani, Patrizia; Locatelli, Anna; Verderio, Maria; Assi, Francesca

2004-01-01

We sought to evaluate whether serial amnioinfusions for persistent oligohydramnios can affect the perinatal and long-term outcomes in extreme cases of preterm premature rupture of membranes. All singleton pregnancies with preterm premature rupture of membranes at <26 weeks'gestation and lasting >4 days between January 1991 and December 2001 were included. Amniotic fluid volume was assessed as the maximum cord-free pocket with serial ultrasonographic examinations. Consenting women with persistent (>4 days) oligohydramnios (amniotic fluid=2 cm) received serial transabdominal amnioinfusions to maintain an amniotic fluid pocket >2 cm. The pregnancy, neonatal, and long-term neurologic outcomes of the cases that spontaneously maintained a median amniotic fluid pocket >2 cm were compared with those of women with oligohydramnios who underwent amnioinfusion but continued to have persistent oligohydramnios and with those of women in whom oligohydramnios was alleviated. Statistical analysis included the Wilcoxon rank-sum test and the Fisher exact test with a 2-tailed P<0.05 considered significant. Stepwise logistic regression analysis with the Nagelkerke adaptation of the Cox-Snell R2 was performed to assess prenatal predictors of survival in the persistent ologohydramnios group. Among the 49 women included in the study, 13 (26.5%) did not have oligohydramnios, the neonatal survival rate was 92%, and normal fetal lung development and neurologic outcome were achieved in all survivors. The remaining 36 women had oligohydramnios, and all underwent serial amnioinfusions, which successfully restored a median amniotic fluid pocket >2 cm for =48 hours in 11 (30%) patients. This successful amnioinfusion group was comparable with the persistent oligohydramnios group (n=25) in gestational age at first amnioinfusion (median, 20.2 weeks; range, 16-25.6 weeks; vs median, 20.3 weeks; range, 16.5-24.2 weeks; P=.4), number of amnioinfusions (median, 3; range, 1-9; vs median, 3; range, 1-5; P=.4), and interval between amnioinfusions (median, 6 days; range, 4-14 days; vs median, 8 days; range, 6-43 days; P=.1). However, patients in the persistent oligohydramnios group had a significantly shorter interval to delivery, lower neonatal survival (20%), and higher rates of pulmonary hypoplasia (62%) and abnormal neurologic outcomes (60%) than the patients in the groups in which amnioinfusion was not necessary or was successful (all P=.01). Logistic regression analysis demonstrated that after taking into consideration successful amnioinfusion (P=0.019) and administration of steroids (P=0.022), none of the other variables, including gestational age at delivery, contributed significantly to the prediction of perinatal survival in the persistent oligohydramnios group. Pregnancies with preterm premature rupture of membranes-related oligohydramnios at <26 weeks' gestation in which serial amnioinfusions successfully alleviate oligohydramnios have a perinatal outcome that is significantly better than the outcome in those with persistent oligohydramnios and is comparable with gestations with preterm premature rupture of membranes in which oligohydramnios never develops. In the persistent oligohydramnios group, successful procedures and prenatal administration of corticosteroids are the only independent predictors of perinatal survival.

Stochastic Modeling of the Persistence of HIV: Early Population Dynamics

DTIC Science & Technology

2013-05-10

fluid, Brownian motion is named after the botanist Robert Brown. In the late nineteenth century, he observed that pollen floating in water appeared...to move about in a random manner. When he replaced the pollen with inorganic material, he noticed that the motion persisted. Upon plotting the motion

Hurst exponent used as a tool to differentiate between magmatic and fluid-induced processes as reflected in crystal geochemistry

NASA Astrophysics Data System (ADS)

Domonik, A.; Słaby, E.; Śmigielski, M.

2012-04-01

A self-similarity parameter, the Hurst exponent (H) (called also roughness exponent) has been used to show the long-range dependence of element behaviour during the processes. The H value ranges between 0 and 1; a value of 0.5 indicates a random distribution indistinguishable from noise. For values greater or less than 0.5, the system shows non-linear dynamics. H < 0.5 represents anti-persistent (more chaotic) behaviour, whereas H > 0.5 corresponds to increasing persistence (less chaotic). Such persistence is characterized as an effect of a long-term memory, and thus by a large degree of positive correlation. In theory, the preceding data constantly affect the next in the whole temporal series. Applied to chaotic dynamics, the system shows a subtle sensitivity to initial conditions. The process can show some degree of chaos, due to local variations, but generally, the trend preserves its persistent character through time. If the exponent value is low, the process shows frequent and sudden reversals e.g. the trends of such a process show mutual negative correlation of the succeding values in the data series. Thus, the system can be described as having a high degree of deterministic chaos. Alkali feldspar megacrysts grown from mixed magmas and recrystallized due to interaction with fluids have been selected for the study (Słaby et al., 2011). Hurst exponent variability has been calculated within some primary-magmatic and secondary-recrystallized crystal domains for some elements redistributed by crystal fluid interaction. Based on the Hurst exponent value two different processes can easily be recognized. In the core of the megacrysts the element distribution can be ascribed to magmatic growth. By contrast, the marginal zones can relate to inferred late crystal-fluid interactions. Both processes are deterministic, not random. The spatial distribution of elements in the crystal margins is irregular, with high-H values identifying the process as persistent. The trace element distributions in feldspar cores are almost homogeneous and only relatively small and irregular variations in trace element contents makes their growth morphology slightly patchy. Despite homogenization the fractal statistics reveal that trace elements were incorporated chaotically into the growing crystal. The anti-persistent chaotic behaviour of elements during magmatic growth of the feldspars progressively changes into persistent behaviour within domains, where re-crystallization reaction took place. Elements demonstrate variable dynamics of this exchange corresponding to increasing persistency. This dynamics is different for individual elements compared to analogical, observed for crystallization process proceeding from mixed magmas. Consequently, it appears that fractal statistics clearly discriminate between two different processes, with contrasted element behaviour during these processes. One process is magma crystallization and it is recorded in the core of the megacrysts; the second is recorded in the crystal rims and along cleavages and cracks, such that it can be related to a post-crystallization process linked to fluid percolation. Słaby, E., Martin, H., Hamada, M., Śmigielski, M., Domonik, A., Götze, J., Hoefs, J., Hałas, S., Simon, K., Devidal, J-L., Moyen, J-F., Jayananda, M. (2011) Evidence in Archaean alkali-feldspar megacrysts for high-temperature interaction with mantle fluids. Journal of Petrology (on line). doi:10.1093/petrology/egr056

A persistent change in subcellular distribution of calcineurin following fluid percussion injury in the rat.

PubMed

Kurz, Jonathan E; Hamm, Robert J; Singleton, Richard H; Povlishock, John T; Churn, Severn B

2005-06-28

Calcineurin, a neuronally enriched, calcium-stimulated phosphatase, is an important modulator of many neuronal processes, including several that are physiologically related to the pathology of traumatic brain injury. The effect of moderate, central fluid percussion injury on the subcellular distribution of this important neuronal enzyme was examined. Animals were sacrificed at several time points post-injury and calcineurin distribution in subcellular fractions was assayed by Western blot analysis and immunohistochemistry. A persistent increase in calcineurin concentration was observed in crude synaptoplasmic membrane-containing fractions. In cortical fractions, calcineurin immunoreactivity remained persistently increased for 2 weeks post-injury. In hippocampal homogenates, calcineurin immunoreactivity remained increased for up to 4 weeks. Finally, immunohistochemical analysis of hippocampal slices revealed increased staining in the apical dendrites of CA1 neurons. The increased staining was greatest in magnitude 24 h post-injury; however, staining was still more intense than control 4 weeks post-injury. The data support the conclusion that fluid percussion injury results in redistribution of the enzyme in the rat forebrain. These changes have broad physiological implications, possibly resulting in altered cellular excitability or a greater likelihood of neuronal cell death.

Oil Based Drilling Fluid Waste: An Overview on Environmentally Persistent Pollutants

NASA Astrophysics Data System (ADS)

Siddique, Shohel; Kwoffie, Lorraine; Addae-Afoakwa, Kofi; Yates, Kyari; Njuguna, James

2017-05-01

Operational discharges of spent drilling fluid, produced water, and accumulated drill cuttings from oil and gas industry are a continuous point source of environmental pollution. To meet the strict environmental standard for waste disposal, oil and gas industry is facing a numerous challenges in technological development to ensure a clean and safe environment. Oil and gas industry generates a large amount of spent drilling fluid, produced water, and drill cuttings, which are very different in every drilling operation in terms of composition and characterisation. This review article highlights the knowledge gap in identifying the different sources of waste streams in combined drilling waste. This paper also emphasises how different chemicals turn into environmentally significant pollutants after serving great performance in oil and gas drilling operations. For instance, oil based drilling fluid performs excellent in deeper drilling and drilling in the harsh geological conditions, but ended with (produces) a significant amount of persistent toxic pollutants in the environment. This review paper provides an overview on the basic concepts of drilling fluids and their functions, sources and characterisation of drilling wastes, and highlights some environmentally significant elements including different minerals present in drilling waste stream.

[Maculopathy caused by Nd:YAG laser accident].

PubMed

Blümel, C; Brosig, J

1999-02-01

Since the construction of the first laser in the sixties and the extended use in medicine, technology and hobby the number of accidents has increased. Appreciated to therapy concepts are missing at the time. A 19 year-old-man was hit by the impulse of an military hand-held rangefinder (Nd:YAG with a wavelength of 1064 nm) on the right eye. The visual acuity dropped to 1/35 and a central scotoma with metamorphopsia occurred immediatly after the accident. The ophthalmological findings showed a distinct submacular hemorrhage. The therapy with Prednisolon intravenous and daily parabulbar, vitamin C, indomethacin systemical and lokal application resulted in an increase of visual acuity up to 0.4 and a reduction of central scotoma from 8 degrees to 2 degrees. Systemical and local use of antiphlogistic and antiinflamatoric substances may partially reduce the vision limitating scar formation. Application of antioxidants to neutralize the toxic radicals that arise by tissue decay should be given additionally to the cyclopegic medication. Special attention should be payed to the prevention of such laser accidents.

Comparison of detection of BVDV antigen in various types of tissue and fluid samples collected from persistently infected cattle

USDA-ARS?s Scientific Manuscript database

Aim. Bovine viral diarrhea viruses (BVDV) are economically important pathogens of cattle. Most new acute infections of BVDV are acquired from an animal persistently infected (PI) with BVDV. Surveillance programs typically rely on blood or skin biopsies for detection of PI cattle. PI animals have ...

Enhanced Remedial Amendment Delivery to Subsurface Using Shear Thinning Fluid and Aqueous Foam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Lirong; Szecsody, James E.; Oostrom, Martinus

2011-04-23

A major issue with in situ subsurface remediation is the ability to achieve an even spatial distribution of remedial amendments to the contamination zones in an aquifer or vadose zone. Delivery of amendment to the aquifer using shear thinning fluid and to the vadose zone using aqueous foam has the potential to enhance the amendment distribution into desired locations and improve the remediation. 2-D saturated flow cell experiments were conducted to evaluate the enhanced sweeping, contaminant removal, and amendment persistence achieved by shear thinning fluid delivery. Bio-polymer xanthan gum solution was used as the shear thinning fluid. Unsaturated 1-D columnmore » and 2-D flow cell experiments were conducted to evaluate the mitigation of contaminant mobilization, amendment uniform distribution enhancement, and lateral delivery improvement by foam delivery. Surfactant sodium lauryl ether sulfate was used as the foaming agent. It was demonstrated that the shear thinning fluid injection enhanced the fluid sweeping over a heterogeneous system and increased the delivery of remedial amendment into low-permeability zones. The persistence of the amendment distributed into the low-perm zones by the shear thinning fluid was prolonged compared to that of amendment distributed by water injection. Foam delivery of amendment was shown to mitigate the mobilization of highly mobile contaminant from sediments under vadose zone conditions. Foam delivery also achieved more uniform amendment distribution in a heterogeneous unsaturated system, and demonstrated remarkable increasing in lateral distribution of the injected liquid compared to direct liquid injection.« less

Investigating a persistent odor at an aircraft seat manufacturer.

PubMed

Broadwater, Kendra; de Perio, Marie A; Roberts, Jennifer; Burton, Nancy C; Lemons, Angela R; Green, Brett J; Brueck, Scott E

2016-10-01

An aircraft seat manufacturing company requested a NIOSH health hazard evaluation to help identify a strong odor that had persisted throughout the facility for over a year. Employees reported experiencing health effects thought to be related to the odor. We collected and analyzed area air samples for volatile organic compounds, endotoxin, bacterial and fungal metagenome, and metalworking fluid aerosol. Bulk metalworking fluid samples were analyzed for endotoxin, bacterial and fungal metagenome, and viable bacteria and fungus. We also evaluated the building ventilation systems and water diversion systems. Employees underwent confidential medical interviews about work practices, medical history, and health concerns. Based on our analyses, the odor was likely 2-methoxy-3,5-dimethylpyrazine. This pyrazine was found in air samples across the facility and originated from bacteria in the metalworking fluid. We did not identify bacteria known to produce the compound but bacteria from the same Proteobacteria order were found as well as bacteria from orders known to produce other pyrazines. Chemical and biological contaminants and odors could have contributed to health symptoms reported by employees, but it is likely that the symptoms were caused by several factors. We provided several recommendations to eliminate the odor including washing and disinfecting the metalworking machines and metalworking fluid recycling equipment, discarding all used metalworking fluid, instituting a metalworking fluid maintenance program at the site, and physically isolating the metalworking department from other departments.

Investigating a persistent odor at an aircraft seat manufacturer

PubMed Central

Broadwater, Kendra; de Perio, Marie A.; Roberts, Jennifer; Burton, Nancy C.; Lemons, Angela R.; Green, Brett J.; Brueck, Scott E.

2017-01-01

An aircraft seat manufacturing company requested a NIOSH health hazard evaluation to help identify a strong odor that had persisted throughout the facility for over a year. Employees reported experiencing health effects thought to be related to the odor. We collected and analyzed area air samples for volatile organic compounds, endotoxin, bacterial and fungal metagenome, and metalworking fluid aerosol. Bulk metalworking fluid samples were analyzed for endotoxin, bacterial and fungal metagenome, and viable bacteria and fungus. We also evaluated the building ventilation systems and water diversion systems. Employees underwent confidential medical interviews about work practices, medical history, and health concerns. Based on our analyses, the odor was likely 2-methoxy-3,5-dimethylpyrazine. This pyrazine was found in air samples across the facility and originated from bacteria in the metalworking fluid. We did not identify bacteria known to produce the compound but bacteria from the same Proteobacteria order were found as well as bacteria from orders known to produce other pyrazines. Chemical and biological contaminants and odors could have contributed to health symptoms reported by employees, but it is likely that the symptoms were caused by several factors. We provided several recommendations to eliminate the odor including washing and disinfecting the metalworking machines and metalworking fluid recycling equipment, discarding all used metal-working fluid, instituting a metalworking fluid maintenance program at the site, and physically isolating the metalworking department from other departments. PMID:27494786

Hands-On Tabletop Units for Addressing Persistent Conceptual Difficulties in Continuity and Frictional Loss in Fluid Mechanics

ERIC Educational Resources Information Center

Li, Xuesong; Van Wie, Bernard J.

2016-01-01

The difficulty in covering chemical engineering concepts using traditional lectures and whiteboard teaching approaches means today's students' learning demands are unfulfilled, so alternate methods are needed. Desktop learning modules (DLMs) are designed to show industrial fluid flow and heat transfer concepts in a standard classroom so students…

Persistence of Pneumolysin in the Cerebrospinal Fluid of Patients With Pneumococcal Meningitis Is Associated With Mortality

PubMed Central

Wall, Emma C.; Hussain, Samia; Goonetilleke, Upali R. S.; Gritzfeld, Jenna; Scarborough, Matthew; Kadioglu, Aras

2012-01-01

Poor prognosis in Pneumococcal meningitis may be associated with high pneumolysin levels in cerebrospinal fluid (CSF). In patient samples we showed that pneumolysin levels in CSF remained high after 48 hours in nonsurvivors of meningitis compared with survivors. Selective antipneumolysin treatment may present a novel therapeutic option. PMID:22238165

Induced seismicity in EGS reservoir : analysis of persistent multiplets at Soultz-sous-Forêts, France

NASA Astrophysics Data System (ADS)

Cauchie, Léna; Lengliné, Olivier; Schmittbuhl, Jean

2017-04-01

Abundant seismicity is generally observed during the exploitation of geothermal reservoirs, especially during phases of hydraulic stimulations. At the Enhanced Geothermal System of Soultz-Sous-Forêts in France, the induced seismicity has been thoroughly studied over the years of exploitation and the mechanism at its origin has been related to both fluid pressure increase during stimulation and aseismic creeping movements. The fluid-induced seismic events often exhibit a high degree of similarity and the mechanism at the origin of these repeated events is thought to be associated with slow slip process where asperities on the rupture zone act several times. In order to improve our knowledge on the mechanisms associated with such events and on the damaged zones involved during the hydraulic stimulations, we investigate the behaviour of the multiplets and their persistent nature, if it prevails, over several water injection intervals. For this purpose, we analysed large datasets recorded from a downhole seismic network for several water injection periods (1993, 2000, …). For each stimulation interval, thousands of events are recorded at depth. We detected the events using the continuous kurtosis-based migration method and classified them into families of comparable waveforms using an approach based on cross-correlation analysis. We obtain precise relative locations of the multiplets using differential arrival times obtained through cross-correlation of similar waveforms. Finally, the properties of the similar fluid-induced seismic events are derived (magnitude, spectral content) and examined over the several hydraulic tests. Hopefully these steps will lead to a better understanding of the repetitive nature of these events and the investigation of their persistence will outline the heterogeneities of the structures (temperatures anomalies, regional stress perturbations, fluid flow channelling) regularly involved during the different stimulations.

NEONATAL CEREBRAL MORPHOMETRY AND LATER RISK OF PERSISTENT INATTENTION/HYPERACTIVITY IN CHILDREN BORN VERY PRETERM

PubMed Central

Bora, Samudragupta; Pritchard, Verena E.; Chen, Zhe; Inder, Terrie E.; Woodward, Lianne J.

2014-01-01

Background Attention problems are among the most prevalent neurobehavioral morbidities affecting very preterm (VPT) born children. The first study aim was to document rates of persistent attention/hyperactivity problems from ages 4 to 9 years in a regional cohort of VPT born children. The second aim was to examine the extent to which persistent problems were related to cerebral white matter abnormality and structural development on neonatal MRI. Methods Data were drawn from a prospective longitudinal study of 110 VPT (≤32 weeks’ gestation) and 113 full-term (FT) children born from 1998 to 2000. At term equivalent, all VPT and 10 FT children underwent cerebral structural MRI, with scans analyzed qualitatively for white matter abnormalities and quantitatively for cortical and subcortical gray matter, myelinated and unmyelinated white matter, and cerebrospinal fluid volumes. At ages 4, 6, and 9 years, each child’s parent and teacher completed the Inattention/Hyperactivity subscale of the Strengths and Difficulties Questionnaire. Results VPT born children had a 5-fold increased risk of persistent attention/hyperactivity problems compared to FT children (13.1% vs. 2.8%; p=.002). No association was found between neonatal white matter abnormalities and later persistent inattention/hyperactivity risk (p≥.24). In contrast, measures of cerebral structural development including volumetric estimates of total cerebral tissue and cerebrospinal fluid relative to intracranial volume were associated with an increased risk of persistent attention/hyperactivity problems in VPT born children (p=.001). The dorsal prefrontal region showed the largest volumetric reduction (↓3.2–8.2ml). These brain-behavior associations persisted and in some cases, strengthened after covariate adjustment for postmenstrual age at MRI, sex, and family socioeconomic status. Conclusions Just over one in 10 VPT born children are subject to early onset and persistent attention/hyperactivity problems during childhood. These problems appear to reflect, at least in part, neonatal disturbances in cerebral growth and development rather than the effects of white matter injury. PMID:24438003

Cytomegalovirus infection in immunocompetent wheezy infants: the diagnostic value of CMV PCR in bronchoalveolar lavage fluid.

PubMed

Cinel, G; Pekcan, S; Ozçelik, U; Alp, A; Yalçın, E; Doğru Ersöz, D; Kiper, N

2014-08-01

Cytomegalovirus (CMV) pneumonitis in immunocompetent hosts is uncommon but is being recognized more frequently, particularly when presenting as severe viral pneumonia. The objective of this study was to examine lower respiratory tract CMV infection in immunocompetent wheezy infants, based on polymerase chain reaction (PCR) in bronchoalveolar lavage (BAL) fluid, to compare CMV PCR results in BAL and in blood samples and to evaluate the benefits of antiviral ganciclovir therapy in these patients. Retrospective review of the records of patients referred to our tertiary care hospital between January 2000 and July 2010 who had unexplained persistent wheezing and underwent fibreoptic flexible bronchoscopy (FFB). Fibreoptic flexible bronchoscopy was applied to 102 infants with persistent wheezing and diffuse interstitial infiltration on radiological investigations; so CMV PCR in BAL fluid was performed. CMV PCR in BAL fluid was positive in 51 patients. Retrospectively, we had access to the files of 25 of these patients. The mean CMV PCR in BAL fluid was 334 840 copies/mL. Only eight patients had CMV PCR positivity in their blood samples (mean: 2026·3 copies/mL). There was not a relationship between BAL and blood CMV PCR values based on Spearman's correlation analysis (r = -0·008). Fourteen patients had severe respiratory symptoms and received ganciclovir therapy. Twelve of them fully recovered. Bronchoalveolar lavage fluid CMV PCR was superior to blood CMV PCR in diagnosing lower respiratory tract infections caused by CMV in immunocompetent infants. Ganciclovir therapy may be effective in selected immunocompetent wheezy infants with CMV PCR positivity in BAL fluid. © 2014 John Wiley & Sons Ltd.

NATURAL COURSE OF PATIENTS DISCONTINUING TREATMENT FOR AGE-RELATED MACULAR DEGENERATION AND FACTORS ASSOCIATED WITH VISUAL PROGNOSIS.

PubMed

Kim, Jae Hui; Chang, Young Suk; Kim, Jong Woo

2017-12-01

To evaluate the 24-month natural course of visual changes in patients discontinuing treatment despite persistent or recurrent fluid and factors predictive of visual prognosis. This retrospective, observational study included 35 patients (35 eyes) who initially received anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD), but discontinued treatment despite persistent or recurrent fluid. The best-corrected visual acuity (BCVA) at treatment discontinuation was determined and compared with the 24-month BCVA, which was then compared between polypoidal choroidal vasculopathy and other neovascular age-related macular degeneration subtypes. Baseline characteristics predictive of visual outcome and the degree of visual change were also analyzed. The mean number of anti-vascular endothelial growth factor injections before treatment discontinuation was 4.0 ± 1.6. The mean logarithm of minimal angle of resolution of BCVA at treatment discontinuation and that at 24 months were 1.02 ± 0.20 (Snellen equivalents = 20/209) and 1.60 ± 0.56 (20/796), respectively (P < 0.001). The 24-month BCVA was not different between polypoidal choroidal vasculopathy and other neovascular age-related macular degeneration subtypes (P = 0.803). The type of fluid (intraretinal fluid vs. no intraretinal fluid) was predictive of 24-month BCVA (P = 0.004) and the degree of changes in BCVA (P = 0.043). Marked deterioration in visual acuity was noted in patients discontinuing treatment, regardless of neovascular age-related macular degeneration subtypes. The presence of intraretinal fluid was associated with worse visual prognosis, suggesting that patients with intraretinal fluid should be strongly warned about their poor prognosis before they decide to discontinue treatment.

Fault geometry and fluid-rock reaction: Combined controls on mineralization in the Xinli gold deposit, Jiaodong Peninsula, China

NASA Astrophysics Data System (ADS)

Yang, Lin; Zhao, Rui; Wang, Qingfei; Liu, Xuefei; Carranza, Emmanuel John M.

2018-06-01

The structures and fluid-rock reaction in the Xinli gold deposit, Jiaodong Peninsula, were investigated to further understand their combined controls on the development of permeability associated with ore-forming fluid migration. Orebodies in this deposit are hosted by the moderately SE-to S-dipping Sanshandao-Cangshang fault (SCF). Variations in both dip direction and dip angle along the SCF plane produced fault bends, which controlled the fluid accumulation and ore-shoot formation. Gold mineralizations occurred in early gold-quartz-pyrite and late gold-quartz-polymetallic sulphide stages following pervasive sericitization and silicification alterations. Theoretical calculation indicates that sericitization caused 8-57% volume decrease resulting in the development/enlargement of voids, further increase of grain-scale permeability, and resultant precipitation of the early gold-quartz-pyrite pods, which destroyed permeability. The rock softening produced by alterations promoted activities of SCF secondary faults and formation of new fractures, which rebuilt the permeability and controlled the late gold-quartz-polymetallic sulfide veins. Quantitative studies on permeability distributions show that the southwestern and northeastern bend areas with similar alteration and mineralization have persistent and anti-persistent permeability networks, respectively. These were likely caused by different processes of rebuilding permeability due to different stress states resulting from changes in fault geometry.

Bedside sonography for the diagnosis of esophageal food impaction.

PubMed

Singleton, Jennifer; Schafer, Jesse M; Hinson, Jeremiah S; Kane, Erin M; Wright, Sherieka; Hoffmann, Beatrice

2017-05-01

Esophageal foreign body (EFB) and impaction are common gastrointestinal emergencies. Detection with standard imaging can be challenging. Computed tomography is a commonly used non-invasive imaging modality, but is not 100% sensitive and not always feasible. Sensitivity of plain film x-ray varies widely and the addition of a barium swallow can obscure evaluation by subsequent esophagogastroduodenoscopy (EGD). Use of emergency ultrasound (EUS) for detection of EFB in adults has not been previously studied. To evaluate the role of EUS in detection of EFB and to characterize sonographic findings. A case control series of five patients with clinical suspicion of EFB underwent EUS, and findings were compared to five healthy controls. Patients were evaluated for persistent air-fluid levels after swallowing, esophageal dilatation, and visualization of EFB. All patients with suspected EFB had esophageal dilatation (17.5mm vs 9.3mm in healthy controls; p=0.0011) and persistent air-fluid levels after swallowing. EFB was visualized on EUS in 60% of patients. All patients had EFB confirmed on EGD except one, who vomited a significant food bolus during EUS and prior to EGD. In patients with suspected EFB, point-of-care ultrasound may identify those with impaction. Suggestive findings include cervical esophageal dilatation and persistent intraluminal air-fluid levels after swallowing. EUS is a rapid, convenient test with the potential to expedite definitive management while decreasing cost and radiation exposure in this patient population. Copyright © 2017 Elsevier Inc. All rights reserved.

Co-infection of classic swine H1N1 influenza virus in pigs persistently infected with porcine rubulavirus.

PubMed

Rivera-Benitez, José Francisco; De la Luz-Armendáriz, Jazmín; Saavedra-Montañez, Manuel; Jasso-Escutia, Miguel Ángel; Sánchez-Betancourt, Ivan; Pérez-Torres, Armando; Reyes-Leyva, Julio; Hernández, Jesús; Martínez-Lara, Atalo; Ramírez-Mendoza, Humberto

2016-02-29

Porcine rubulavirus (PorPV) and swine influenza virus infection causes respiratory disease in pigs. PorPV persistent infection could facilitate the establishment of secondary infections. The aim of this study was to analyse the pathogenicity of classic swine H1N1 influenza virus (swH1N1) in growing pigs persistently infected with porcine rubulavirus. Conventional six-week-old pigs were intranasally inoculated with PorPV, swH1N1, or PorPV/swH1N1. A mock-infected group was included. The co-infection with swH1N1 was at 44 days post-infection (DPI), right after clinical signs of PorPV infection had stopped. The pigs of the co-infection group presented an increase of clinical signs compared to the simple infection groups. In all infected groups, the most recurrent lung lesion was hyperplasia of the bronchiolar-associated lymphoid tissue and interstitial pneumonia. By means of immunohistochemical evaluation it was possible to demonstrate the presence of the two viral agents infecting simultaneously the bronchiolar epithelium. Viral excretion of PorPV in nasal and oral fluid was recorded at 28 and 52 DPI, respectively. PorPV persisted in several samples from respiratory tissues (RT), secondary lymphoid organs (SLO), and bronchoalveolar lavage fluid (BALF). For swH1N1, the viral excretion in nasal fluids was significantly higher in single-infected swH1N1 pigs than in the co-infected group. However, the co-infection group exhibited an increase in the presence of swH1N1 in RT, SLO, and BALF at two days after co-infection. In conclusion, the results obtained confirm an increase in the clinical signs of infection, and PorPV was observed to impact the spread of swH1N1 in analysed tissues in the early stage of co-infection, although viral shedding was not enhanced. In the present study, the interaction of swH1N1 infection is demonstrated in pigs persistently infected with PorPV. Copyright © 2016 Elsevier B.V. All rights reserved.

Natural resolution or intervention for fluid collections in acute severe pancreatitis.

PubMed

Sarathi Patra, P; Das, K; Bhattacharyya, A; Ray, S; Hembram, J; Sanyal, S; Dhali, G K

2014-12-01

Revisions in terminology of fluid collections in acute pancreatitis have necessitated reanalysis of their evolution and outcome. The course of fluid collections in patients with acute pancreatitis was evaluated prospectively. Consecutive adults with acute pancreatitis, who had contrast-enhanced CT (CECT) within 5-7 days of symptom onset, were enrolled in a prospective cohort study in a tertiary-care centre. Patients were treated according to standard guidelines. Follow-up transabdominal ultrasonography was done at 4-week intervals for at least 6 months. CECT was repeated at 6-10 weeks, or at any time if there were new or persistent symptoms. Asymptomatic collections were followed until spontaneous resolution. Risk factors for pancreatic pseudocysts or walled-off necrosis (WON) were assessed in multivariable analyses. Of 122 patients with acute pancreatitis, 109 were analysed. Some 91 patients (83·5 per cent) had fluid collections at baseline. Eleven of 29 with interstitial oedematous pancreatitis had acute peripancreatic fluid collections, none of which evolved into pseudocysts. All 80 patients with acute necrotizing pancreatitis had at least one acute necrotizing collection (ANC); of these, five patients died (2 after drainage), three underwent successful drainage within 5 weeks, and collections resolved spontaneously in 33 and evolved into WON in 39. By 6 months' follow-up, WON had required drainage in eight patients, resolved spontaneously in 23 and was persistent but asymptomatic in seven. Factors associated with increased risk of WON were blood urea nitrogen 20 mg/dl or more (odds ratio (OR) 10·96, 95 per cent c.i. 2·57 to 46·73; P = 0·001) and baseline ANC diameter greater than 6 cm (OR 14·57, 1·60 to 132·35; P = 0·017). Baseline ANC diameter over 6 cm was the only independent predictor of either the need for drainage or persistence of such collections beyond 6 months (hazard ratio 6·61, 1·77 to 24·59; P = 0·005). Pancreatic pseudocysts develop infrequently in oedematous acute pancreatitis. Only one-quarter of ANCs either require intervention or persist beyond 6 months, whereas more than one-half of WONs resolve without any intervention within 6 months of onset. Baseline diameter of ANC(s) is an important predictor of outcome. © 2014 BJS Society Ltd. Published by John Wiley & Sons Ltd.

Carbon nanostructure based mechano-nanofluidics

NASA Astrophysics Data System (ADS)

Cao, Wei; Wang, Jin; Ma, Ming

2018-03-01

Fast transport of water inside carbon nanostructures, such as carbon nanotubes and graphene-based nanomaterials, has addressed persistent challenges in nanofluidics. Recently reported new mechanisms show that the coupling between phonons in these materials and fluids under-confinement could lead to the enhancement of the diffusion coefficient. These developments have led to the emerging field of mechano-nanofluidics, which studies the effects of mechanical actuations on the properties of nanofluidics. In this tutorial review, we provide the basic concepts and development of mechano-nanofluidics. We also summarize the current status of experimental observations of fluids flow in individual nanochannels and theoretical interpretations. Finally, we briefly discuss the challenges and opportunities for the utilization of mechano-nanofluidics, such as controlling the fluid flow through regulating the coupling between materials and fluids.

Confined semiflexible polymers suppress fluctuations of soft membrane tubes.

PubMed

Mirzaeifard, Sina; Abel, Steven M

2016-02-14

We use Monte Carlo computer simulations to investigate tubular membrane structures with and without semiflexible polymers confined inside. At small values of membrane bending rigidity, empty fluid and non-fluid membrane tubes exhibit markedly different behavior, with fluid membranes adopting irregular, highly fluctuating shapes and non-fluid membranes maintaining extended tube-like structures. Fluid membranes, unlike non-fluid membranes, exhibit a local maximum in specific heat as their bending rigidity increases. The peak is coincident with a transition to extended tube-like structures. We further find that confining a semiflexible polymer within a fluid membrane tube reduces the specific heat of the membrane, which is a consequence of suppressed membrane shape fluctuations. Polymers with a sufficiently large persistence length can significantly deform the membrane tube, with long polymers leading to localized bulges in the membrane that accommodate regions in which the polymer forms loops. Analytical calculations of the energies of idealized polymer-membrane configurations provide additional insight into the formation of polymer-induced membrane deformations.

Laparoscopy

MedlinePlus

... Laparoscopy may be done to remove an ectopic pregnancy. • Pelvic floor disorders —Laparoscopic surgery can be used to ... vagina. Chronic Pelvic Pain: Persistent pain in the pelvic region that has ... fluid. Ectopic Pregnancy: A pregnancy in which the fertilized egg begins ...

Short- and long-term olivine weathering in Svalbard: implications for Mars.

PubMed

Hausrath, E M; Treiman, A H; Vicenzi, E; Bish, D L; Blake, D; Sarrazin, P; Hoehler, T; Midtkandal, I; Steele, A; Brantley, S L

2008-12-01

Liquid water is essential to life as we know it on Earth; therefore, the search for water on Mars is a critical component of the search for life. Olivine, a mineral identified as present on Mars, has been proposed as an indicator of the duration and characteristics of water because it dissolves quickly, particularly under low-pH conditions. The duration of olivine persistence relative to glass under conditions of aqueous alteration reflects the pH and temperature of the reacting fluids. In this paper, we investigate the utility of 3 methodologies to detect silicate weathering in a Mars analog environment (Sverrefjell volcano, Svalbard). CheMin, a miniature X-ray diffraction instrument developed for flight on NASA's upcoming Mars Science Laboratory, was deployed on Svalbard and was successful in detecting olivine and weathering products. The persistence of olivine and glass in Svalbard rocks was also investigated via laboratory observations of weathered hand samples as well as an in situ burial experiment. Observations of hand samples are consistent with the inference that olivine persists longer than glass at near-zero temperatures in the presence of solutions at pH approximately 7-9 on Svalbard, whereas in hydrothermally altered zones, glass has persisted longer than olivine in the presence of fluids at similar pH at approximately 50 degrees C. Analysis of the surfaces of olivine and glass samples, which were buried on Sverrefjell for 1 year and then retrieved, documented only minor incipient weathering, though these results suggest the importance of biological impacts. The 3 types of observations (CheMin, laboratory observations of hand samples, burial experiments) of weathering of olivine and glass at Svalbard show promise for interpretation of weathering on Mars. Furthermore, the weathering relationships observed on Svalbard are consistent with laboratory-measured dissolution rates, which suggests that relative mineral dissolution rates in the laboratory, in concert with field observations, can be used to yield valuable information regarding the pH and temperature of reacting martian fluids.

Study on the persistence of Zika virus (ZIKV) in body fluids of patients with ZIKV infection in Brazil.

PubMed

Calvet, Guilherme Amaral; Kara, Edna Oliveira; Giozza, Silvana Pereira; Bôtto-Menezes, Camila Helena Aguiar; Gaillard, Philippe; de Oliveira Franca, Rafael Freitas; de Lacerda, Marcus Vinicius Guimarães; da Costa Castilho, Marcia; Brasil, Patrícia; de Sequeira, Patrícia Carvalho; de Mello, Maeve Brito; Bermudez, Ximena Pamela Diaz; Modjarrad, Kayvon; Meurant, Robyn; Landoulsi, Sihem; Benzaken, Adele Schwartz; de Filippis, Ana Maria Bispo; Broutet, Nathalie Jeanne Nicole

2018-01-22

Zika virus (ZIKV) has been identified in several body fluids of infected individuals. In most cases, it remained detected in blood from few days to 1 week after the onset of symptoms, and can persist longer in urine and in semen. ZIKV infection can have dramatic consequences such as microcephaly and Guillain-Barré syndrome. ZIKV sexual transmission has been documented. A better understanding of ZIKV presence and persistence across biologic compartments is needed to devise rational measures to prevent its transmission. This observational cohort study will recruit non-pregnant participants aged 18 years and above with confirmed ZIKV infection [positive reverse transcriptase-polymerase chain reaction (RT-PCR) test in blood and/or urine]: symptomatic men and women in ZIKV infection acute phase, and their symptomatic or asymptomatic household/sexual infected contacts. Specimens of blood, urine, semen, vaginal secretion/menstrual blood, rectal swab, oral fluids, tears, sweat, urine and breast milk (if applicable) will be collected at pre-established intervals and tested for ZIKV RNA presence by RT-PCR, other co-infection (dengue, Chikungunya, HIV, hepatitis B and C, syphilis), antibody response (including immunoglobulins M and G), plaque reduction neutralization test (if simultaneously positive for ZIKV and dengue), and ZIKV culture and RNA sequencing. Data on socio-demographic characteristics and comorbidities will be collected in parallel. Participants will be followed up for 12 months. This prolonged longitudinal follow-up of ZIKV infected persons with regular biologic testing and data collection will offer a unique opportunity to investigate the presence and persistence of ZIKV in various biologic compartments, their clinical and immunological correlates as well as the possibility of ZIKV reactivation/reinfection over time. This valuable information will substantially contribute to the body of knowledge on ZIKV infection and serve as a base for the development of more effective recommendation on the prevention of ZIKV transmission. NCT03106714 . Registration Date: April, 7, 2017.

Persistence and clearance of Ebola virus RNA from seminal fluid of Ebola virus disease survivors: a longitudinal analysis and modelling study.

PubMed

Sissoko, Daouda; Duraffour, Sophie; Kerber, Romy; Kolie, Jacques Seraphin; Beavogui, Abdoul Habib; Camara, Alseny-Modet; Colin, Géraldine; Rieger, Toni; Oestereich, Lisa; Pályi, Bernadett; Wurr, Stephanie; Guedj, Jeremie; Nguyen, Thi Huyen Tram; Eggo, Rosalind M; Watson, Conall H; Edmunds, W John; Bore, Joseph Akoi; Koundouno, Fara Raymond; Cabeza-Cabrerizo, Mar; Carter, Lisa L; Kafetzopoulou, Liana Eleni; Kuisma, Eeva; Michel, Janine; Patrono, Livia Victoria; Rickett, Natasha Y; Singethan, Katrin; Rudolf, Martin; Lander, Angelika; Pallasch, Elisa; Bockholt, Sabrina; Rodríguez, Estefanía; Di Caro, Antonino; Wölfel, Roman; Gabriel, Martin; Gurry, Céline; Formenty, Pierre; Keïta, Sakoba; Malvy, Denis; Carroll, Miles W; Anglaret, Xavier; Günther, Stephan

2017-01-01

By January, 2016, all known transmission chains of the Ebola virus disease (EVD) outbreak in west Africa had been stopped. However, there is concern about persistence of Ebola virus in the reproductive tract of men who have survived EVD. We aimed to use biostatistical modelling to describe the dynamics of Ebola virus RNA load in seminal fluid, including clearance parameters. In this longitudinal study, we recruited men who had been discharged from three Ebola treatment units in Guinea between January and July, 2015. Participants provided samples of seminal fluid at follow-up every 3-6 weeks, which we tested for Ebola virus RNA using quantitative real-time RT-PCR. Representative specimens from eight participants were then inoculated into immunodeficient mice to test for infectivity. We used a linear mixed-effect model to analyse the dynamics of virus persistence in seminal fluid over time. We enrolled 26 participants and tested 130 seminal fluid specimens; median follow up was 197 days (IQR 187-209 days) after enrolment, which corresponded to 255 days (228-287) after disease onset. Ebola virus RNA was detected in 86 semen specimens from 19 (73%) participants. Median duration of Ebola virus RNA detection was 158 days after onset (73-181; maximum 407 days at end of follow-up). Mathematical modelling of the quantitative time-series data showed a mean clearance rate of Ebola virus RNA from seminal fluid of -0·58 log units per month, although the clearance kinetic varied greatly between participants. Using our biostatistical model, we predict that 50% and 90% of male survivors clear Ebola virus RNA from seminal fluid at 115 days (90% prediction interval 72-160) and 294 days (212-399) after disease onset, respectively. We also predicted that the number of men positive for Ebola virus RNA in affected countries would decrease from about 50 in January 2016, to fewer than 1 person by July, 2016. Infectious virus was detected in 15 of 26 (58%) specimens tested in mice. Time to clearance of Ebola virus RNA from seminal fluid varies greatly between individuals and could be more than 13 months. Our predictions will assist in decision-making about surveillance and preventive measures in EVD outbreaks. This study was funded by European Union's Horizon 2020 research and innovation programme, Directorate-General for International Cooperation and Development of the European Commission, Institut national de la santé et de la recherche médicale (INSERM), German Research Foundation (DFG), and Innovative Medicines Initiative 2 Joint Undertaking. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Laser microprobe analyses of noble gas isotopes and halogens in fluid inclusions: Analyses of microstandards and synthetic inclusions in quartz

USGS Publications Warehouse

Böhlke, J.K.; Irwin, J.J.

1992-01-01

Ar, Kr, Xe, Cl, Br, I, and K abundances and isotopic compositions have been measured in microscopic fluid inclusions in minerals by noble gas mass spectrometry following neutron irradiation and laser extraction. The laser microprobe noble gas mass spectrometric (LMNGMS) technique was quantified by use of microstandards, including air-filled capillary tubes, synthetic basalt glass grains, standard hornblende grains, and synthetic fluid inclusions in quartz. Common natural concentrations of halogens (Cl, Br, and I) and noble gases (Ar and Kr) in trapped groundwaters and hydrothermal fluids can be analyzed simultaneously by LMNGMS in as little as 10−11 L of inclusion fluid, with accuracy and precision to within 5–10% for element and isotope ratios. Multicomponent element and isotope correlations indicate contaminants or persistent reservoirs of excess Xe and/or unfractionated air in some synthetic and natural fluid inclusion samples. LMNGMS analyses of natural fluid inclusions using the methods and calibrations reported here may be used to obtain unique information on sources of fluids, sources of fluid salinity, mixing, boiling (or unmixing), and water-rock interactions in ancient fluid flow systems.

Formation of magmatic brine lenses via focussed fluid-flow beneath volcanoes

NASA Astrophysics Data System (ADS)

Afanasyev, Andrey; Blundy, Jon; Melnik, Oleg; Sparks, Steve

2018-03-01

Many active or dormant volcanoes show regions of high electrical conductivity at depths of a few kilometres beneath the edifice. We explore the possibility that these regions represent lenses of high-salinity brine separated from a single-phase magmatic fluid containing H2O and NaCl. Since chloride-bearing fluids are highly conductive and have an exceptional capacity to transport metals, these regions can be an indication of an active hydrothermal ore-formation beneath volcanoes. To investigate this possibility we have performed hydrodynamic simulations of magma degassing into permeable rock. In our models the magma source is located at 7 km depth and the fluid salinity approximates that expected for fluids released from typical arc magmas. Our model differs from previous models of a similar process because it is (a) axisymmetric and (b) includes a static high-permeability pathway that links the magma source to the surface. This pathway simulates the presence of a volcanic conduit and/or plexus of feeder dykes that are typical of most volcanic systems. The presence of the conduit leads to a number of important hydrodynamic consequences, not observed in previous models. Importantly, we show that an annular brine lens capped by crystallised halite is likely to form above an actively degassing sub-volcanic magma body and can persist for more than 250 kyr after degassing ceases. Parametric analysis shows that brine lenses are more prevalent when the fluid is released at temperatures above the wet granite solidus, when magmatic fluid salinity is high, and when the high-permeability pathway is narrow. The calculated depth, form and electrical conductivity of our modelled system shares many features with published magnetotelluric images of volcano subsurfaces. The formation and persistence of sub-volcanic brine lenses has implications for geothermal systems and hydrothermal ore formation, although these features are not explored in the presented model.

Immune Response and Viral Persistence in Indian Buffaloes (Bubalus bubalis) Infected with Foot-and-Mouth Disease Virus Serotype Asia 1 ▿

PubMed Central

Maddur, Mohan S.; Kishore, Subodh; Gopalakrishna, S.; Singh, Nem; Suryanarayana, V. V.; Gajendragad, Mukund R.

2009-01-01

Despite their potential role in the spread of foot-and-mouth disease (FMD), the immune response and viral persistence in FMD virus (FMDV)-infected Indian buffaloes (Bubalus bubalis) have been unexplored. We found similar kinetics of neutralizing antibody responses in the sera and secretory fluids of buffaloes following experimental FMDV Asia 1 infection, but the lymphocyte-proliferative response in infected buffaloes was of low magnitude. Despite inducing a significant systemic and secretory immune response, viral persistence seems to be a common outcome in buffaloes following FMDV Asia 1 infection, which is associated with a weak cellular immune response. PMID:19828770

On the Construction and Dynamics of Knotted Fields

NASA Astrophysics Data System (ADS)

Kedia, Hridesh

Representing a physical field in terms of its field lines has often enabled a deeper understanding of complex physical phenomena, from Faraday's law of magnetic induction, to the Helmholtz laws of vortex motion, to the free energy density of liquid crystals in terms of the distortions of the lines of the director field. At the same time, the application of ideas from topology--the study of properties that are invariant under continuous deformations--has led to robust insights into the nature of complex physical systems from defects in crystal structures, to the earth's magnetic field, to topological conservation laws. The study of knotted fields, physical fields in which the field lines encode knots, emerges naturally from the application of topological ideas to the investigation of the physical phenomena best understood in terms of the lines of a field. A knot--a closed loop tangled with itself which can not be untangled without cutting the loop--is the simplest topologically non-trivial object constructed from a line. Remarkably, knots in the vortex (magnetic field) lines of a dissipationless fluid (plasma), persist forever as they are transported by the flow, stretching and rotating as they evolve. Moreover, deeply entwined with the topology-preserving dynamics of dissipationless fluids and plasmas, is an additional conserved quantity--helicity, a measure of the average linking of the vortex (magnetic field) lines in a fluid (plasma)--which has had far-reaching consequences for fluids and plasmas. Inspired by the persistence of knots in dissipationless flows, and their far-reaching physical consequences, we seek to understand the interplay between the dynamics of a field and the topology of its field lines in a variety of systems. While it is easy to tie a knot in a shoelace, tying a knot in the the lines of a space-filling field requires contorting the lines everywhere to match the knotted region. The challenge of analytically constructing knotted field configurations has impeded a deeper understanding of the interplay between topology and dynamics in fluids and plasmas. We begin by analytically constructing knotted field configurations which encode a desired knot in the lines of the field, and show that their helicity can be tuned independently of the encoded knot. The nonlinear nature of the physical systems in which these knotted field configurations arise, makes their analytical study challenging. We ask if a linear theory such as electromagnetism can allow knotted field configurations to persist with time. We find analytical expressions for an infinite family of knotted solutions to Maxwell's equations in vacuum and elucidate their connections to dissipationless flows. We present a design rule for constructing such persistently knotted electromagnetic fields, which could possibly be used to transfer knottedness to matter such as quantum fluids and plasmas. An important consequence of the persistence of knots in classical dissipationless flows is the existence of an additional conserved quantity, helicity, which has had far-reaching implications. To understand the existence of analogous conserved quantities, we ask if superfluids, which flow without dissipation just like classical dissipationless flows, have an additional conserved quantity akin to helicity. We address this question using an analytical approach based on defining the particle relabeling symmetry--the symmetry underlying helicity conservation--in superfluids, and find that an analogous conserved quantity exists but vanishes identically owing to the intrinsic geometry of complex scalar fields. Furthermore, to address the question of a ``classical limit'' of superfluid vortices which recovers classical helicity conservation, we perform numerical simulations of \\emph{bundles} of superfluid vortices, and find behavior akin to classical viscous flows.

Naturally occurring and experimentally induced mycoplasmal arthritis of cattle.

PubMed Central

Stalheim, O H; Page, L A

1975-01-01

Mycoplasma agalactiae subsp. bovis strain Iowa 1136 was isolated from synovial fluids of a clinical case of arthritis in cattle on pasture in Iowa. When given to calves and cows by intra-articular or intravenous injection, it caused severe and persistent joint infections with fever, lameness, and swelling of the affected joints, plus synovitis, tendonitis, and fibrinous-purulent synovial fluids of high protein content. Intramammary administration of the organism caused severe mastitis. Calves nursing the cows developed severe mycoplasmal arthritis. PMID:1176623

Endoscopic Transmaxillary Transposition of Temporalis Flap for Recurrent Cerebrospinal Fluid Leak Closure.

PubMed

Thomas, Regi; Girishan, Shabari; Chacko, Ari George

2016-12-01

Objective  To describe the technique of endoscopic transmaxillary temporalis muscle flap transposition for the repair of a persistent postoperative sphenoidal cerebrospinal fluid leak. Design  The repair of a recurrent cerebrospinal fluid leak for a patient who had undergone endoscopic transsphenoidal excision of an invasive silent corticotroph Hardy C and Knosp Grade IV pituitary adenoma was undertaken. The patient had completed postoperative radiotherapy for the residual tumor and presented with cerebrospinal fluid leak, 1 year later. The initial two attempts to repair the cerebrospinal fluid leak with free grafts failed. Therefore, an endoscopic transmaxillary transposition of the temporalis muscle flap was attempted to stop the cerebrospinal fluid leak. Results  The endoscopic transmaxillary transposition of the vascularized temporalis muscle flap onto the cerebrospinal fluid leak repair site resulted in successful closure of the cerebrospinal fluid leak. Conclusion  Endoscopic transmaxillary transposition of the temporalis flap resulted in closure of recurrent cerebrospinal fluid leak in a patient with recurrent pituitary adenoma, who had undergone previous surgery and radiotherapy. This technique has advantages over the endoscopic transpterygoid transposition of the same flap and could be used as a complementary technique in selected patients.

Thickened fluids: investigation of users' experiences and perceptions.

PubMed

Smith, Christina H; Jebson, Emma M; Hanson, Ben

2014-02-01

Fluid thickeners are an important and commonly-used strategy to manage swallowing difficulties however there are no reports of the perceptions and experiences of parents of children using thickeners. Semi-structured interviews of 14 parents having a child using fluid thickeners due to swallowing difficulties. Parents reported improvements in quality of life and health through the use of thickeners. They also reported persistent difficulties in the use of thickeners. Results showed unanimous goodwill and positive attitudes towards thickeners and their observed benefits, tempered by common difficulties with thickeners (variability and unpredictability). There remains scope for improvements of commercial thickeners and in information conveyed to users. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Idiopathic polyhydramnios: persistence across gestation and impact on pregnancy outcomes.

PubMed

Odibo, Imelda N; Newville, Trista M; Ounpraseuth, Songthip T; Dixon, Mandi; Lutgendorf, Monica A; Foglia, Lisa M; Magann, Everett F

2016-04-01

To investigate the likelihood of resolution of idiopathic polyhydramnios in pregnant women and compare outcomes between resolved and persistent cases. One hundred and sixty-three women with idiopathic polyhydramnios who delivered at two medical centers during a 3 year period (January 2012-January 2015) were included in the study. Exclusion criteria included congenital fetal anomalies, maternal diabetes, isoimmunization, fetal infection, placental tumors or anomalies, and multiple gestation. Polyhydramnios was defined as SDP≥8cm or AFI≥24cm. Resolved cases were defined as those with AFI and/or SDP falling and remaining below 24cm and 8cm respectively. Pregnancy outcomes were compared between resolved and persistent cases. Two-sample t-test or Wilcoxon rank-sum test was used for continuous variables while chi-square test or Fisher's exact test was used for categorical measures. Resolution was noted in 61 of 163 (37%) patients. There were no differences in maternal age, gravidity or parity between resolved and persistent cases. Mean gestational age at diagnosis of polyhydramnios and overall mean AFI were significantly lower in the cases that resolved (29.7±4.5 weeks vs 33.4±4.1 weeks, p<0.0001; 23.3±3.5cm vs 25.8 23.3±4.0cm, p=0.0002). Similar to AFI measurements, mean SDP was also lower in cases with resolution (p=0.002). There was no difference in induction rates, mode of delivery, amnioinfusion rates, meconium staining of amniotic fluid and fetal heart rate abnormalities influencing intrapartum management between the two groups. Induction of labor for fetal indication and rupture of membranes were significantly more common in the persistent group. Cesarean delivery for abnormal lie and fetal distress did not differ between the groups. There was an increased risk of macrosomia (>4000g) and preterm delivery (<37 weeks) in the persistent group (p<0.05). Resolution rate was approximately 37% and more likely in cases diagnosed earlier in pregnancy and with lower mean amniotic fluid volume. Preterm delivery and macrosomia were more common in cases that persisted across gestation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Iatrogenic hypervitaminosis D as an unusual cause of persistent vomiting: a case report.

PubMed

Bansal, Rinkesh Kumar; Tyagi, Pankaj; Sharma, Praveen; Singla, Vikas; Arora, Veronica; Bansal, Naresh; Kumar, Ashish; Arora, Anil

2014-02-26

Vitamin D is increasingly recognized to have several beneficial effects. Vitamin D deficiency is widely prevalent. Physicians often treat patients with high doses of vitamin D for various ailments without any monitoring for adverse effects and the prescribed doses often far exceed requirements resulting in toxicity. We present here a classic case of iatrogenic hypervitaminosis D, which presented with persistent vomiting and acute renal failure. Here we present a case of a 45-year-old Asian Indian woman who presented to us with persistent vomiting the cause of which was iatrogenic hypervitaminosis D. She was treated with intravenous fluid, diuretics and calcitonin and had clinical improvement. We suggest that in any patient presenting with persistent vomiting and hypercalcemia, particularly in the presence of normal parathyroid hormone, a diagnosis of overdose of vitamin D should be suspected. Its treatment not only alleviates symptoms but also prevents ongoing acute kidney injury.

Extracellular fluid volume expansion and third space sequestration at the site of small bowel anastomoses.

PubMed

Chan, S T; Kapadia, C R; Johnson, A W; Radcliffe, A G; Dudley, H A

1983-01-01

Intestinal surgery is usually associated with the parenteral administration of sodium and water, sometimes in amounts considerably in excess of excretory capacity. We have studied the effect of this situation on the water content of the gut at and 5 cm from a single-layer end-to-end anastomosis in the rabbit. Water content was measured by desiccation. One group of animals (group 1) did not receive intravenous therapy. The second group (group 2) received 5 ml kg-1 h-1 of Hartmann's solution during the operative period and thereafter to a total volume of 200 ml by 48 h. In group 1 there was a 5-10 per cent increase in tissue weight both at the anastomotic site and at 5 cm (P less than 0.01, Mann-Whitney U test) on the first 3 days. Thereafter, water content at the anastomosis persisted, but resolved in normal gut. In group 2 a further 5 per cent increase in weight over group 1 occurred (P less than 0.01), persistent at the anastomotic site over 5 days, though resolving elsewhere after 2 days. Extracellular fluid volume expansion exaggerates an anatomical third space present in the region of an anastomosis. At the suture line, oedema so induced is persistent and could be deleterious.

The role of ICP monitoring in patients with persistent cerebrospinal fluid leak following spinal surgery: a case series.

PubMed

Craven, Claudia; Toma, Ahmed K; Khan, Akbar A; Watkins, Laurence D

2016-09-01

Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A disturbance in the underlying CSF dynamics could be the causative factor in a small group of patients with refractory CSF leaks that require multiple surgical repairs and prolonged hospital admission. A retrospective case series of patients with persistent post spinal surgery CSF leak referred to the hydrocephalus service for continuous intracranial pressure (ICP) monitoring. Patients' notes were reviewed for medical history, ICP data, radiological data, and subsequent management and outcome. Five patients (two males/three females, mean age, 35.4 years) were referred for ICP monitoring over a 12-month period. These patients had prolonged CSF leak despite multiple repair attempts 252 ± 454 days (mean ± SD). On ICP monitoring, all five patients had abnormal results, with the mean ICP 8.95 ± 4.41 mmHg. Four had abnormal pulse amplitudes, mean 6.15 mmHg ± 1.22 mmHg. All five patients underwent an intervention. Three patients underwent insertion of ventriculoperitoneal (VP) shunts. One patient had venous sinus stent insertion and one patient underwent medical management with acetazolamide. All five of the patients' CSF leak resolved post intervention. The mean time to resolution of CSF leak post intervention was 10.8  ± 12.9 days. Abnormal cerebrospinal fluid dynamics could be the underlying factor in patients with a persistent and treatment-refractory CSF leak post spinal surgery. Treatments aimed at lowering ICP may be beneficial in this group of patients. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be a subject of further study.

[Reassessment of a combination of cerebrospinal fluid scintigraphy and nasal pledget counts in patients with suspected rhinorrhea].

PubMed

Kosuda, S; Arai, S; Hohshito, Y; Tokumitsu, H; Kusano, S; Ishihara, S; Shima, K

1998-07-01

A combination study of cerebrospinal fluid scintigraphy and nasal pledget counts was performed using 37 MBq of 111In-DTPA in 12 patients with suspected rhinorrhea. A pledget was inserted and dwelled in each nasal cavity for 6 hours, with the patient prone during at least 30 minutes. A total of 18 studies was implemented and nasal pledget counting method successfully diagnosed all of CSF rhinorrhea. Diagnosis was possible when pledget counts were greater than 1 kcpm. In patients with persistent, intermittent and occult/no nasal discharge, rhinorrhea was found in 100% (5/5), 60% (3/5), 25% (2/8), respectively. Two cases only exhibited positive scintigraphy. MRI or CT cisternography should be first performed in patients with persistent discharge, but in patients with intermittent/occult discharge pledget counting method might take priority of other diagnostic modalities. In conclusion, nasal pledget counting method is a simple and useful tool for detecting rhinorrhea.

Passive, Collapsible Contingency Urinal for Human Space Flight

NASA Technical Reports Server (NTRS)

Jenson, Ryan

2015-01-01

Fluid transport systems for spacecraft face acute challenges because of the persistently unfamiliar and unforgiving low-gravity environment. IRPI, LLC, has developed a contingency wastewater collection and processing device that provides passive liquid collation, containment, bubble separation, and droplet coalescence functions. The lightweight, low-volume, low-cost, and potentially disposable device may be used for subsequent sampling, metering, storage, disposal, and/or reuse. The approach includes a fractal wetting design that incorporates smart capillary fluidics. This work could have a broad impact on capillary-based fluid management on spacecraft and on Earth.

Persistence, Distribution, and Impact of Distinctly Segmented Microparticles on Cochlear Health following In Vivo Infusion3*

PubMed Central

Ross, Astin M.; Rahmani, Sahar; Prieskorn, Diane M.; Dishman, Acacia F; Miller, Josef M.; Lahann, Joerg; Altschuler, Richard A.

2016-01-01

Delivery of pharmaceuticals to the cochleae of patients with auditory dysfunction could potentially have many benefits from enhancing auditory nerve survival to protecting remaining sensory cells and their neuronal connections. Treatment would require platforms to enable drug delivery directly to the cochlea and increase the potential efficacy of intervention. Cochlear implant recipients are a specific patient subset that could benefit from local drug delivery as more candidates have residual hearing; and since residual hearing directly contributes to post-implantation hearing outcomes, it requires protection from implant insertion-induced trauma. This study assessed the feasibility of utilizing microparticles for drug delivery into cochlear fluids, testing persistence, distribution, biocompatibility, and drug release characteristics. To allow for delivery of multiple therapeutics, particles were composed of two distinct compartments; one containing polylactide-co-glycolide (PLGA), and one composed of acetal-modified dextran and PLGA. Following in vivo infusion, image analysis revealed microparticle persistence in the cochlea for at least 7 days post-infusion, primarily in the first and second turns. The majority of subjects maintained or had only slight elevation in auditory brainstem response thresholds at 7 days post-infusion compared to pre-infusion baselines. There was only minor to limited loss of cochlear hair cells and negligible immune response based on CD45+ immunolabling. When Piribedil-loaded microparticles were infused, Piribedil was detectable within the cochlear fluids at 7 days post-infusion. These results indicate that segmented microparticles are relatively inert, can persist, release their contents, and be functionally and biologically compatible with cochlear function and therefore are promising vehicles for cochlear drug delivery. PMID:26841263

A rare presentation of aspergillus infection as empyema thoracis

PubMed Central

Goel, Manoj K; Juneja, Deven; Jain, Satinder K; Chaudhuri, Saikiran; Kumar, Ajay

2010-01-01

A 57-year-old diabetic and hypertensive man presented with a short history of fever, dry cough and right side chest pain. A chest radiograph showed right pleural based homogenous shadow in middle and lower zones with obliteration of right costo-phrenic angle suggestive of right side effusion. Aspiration of pleural fluid revealed frank pus for which inter-costal tube drainage was performed. Due to persistence of empyema, the patient was subjected to thoracoscopy. Thoracoscopy showed multiloculated empyema. Thoracoscopic pleural biopsy and fluid showed septate fungal hyphae. Thoracotomy and parietal pleurectomy, with resection of part of right lower lobe, was carried out. Pleural fluid, pleural and lung tissue culture grew Aspergillus fumigatus. The patient showed good recovery with voriconazole after thoracotomy. PMID:20539768

Paragonimiasis: a common cause of persistent pleural effusion in Lao PDR.

PubMed

Vidamaly, Sisoupanh; Choumlivong, Khamla; Keolouangkhot, Valy; Vannavong, Nanthasane; Kanpittaya, Jaturat; Strobel, Michel

2009-10-01

Southeast Asia is the major endemic area for paragonimiasis. Diagnosis relies on identification of ova in the sputum, pleural fluid or tissue specimen, or serology. Low awareness, however, frequently results in the disease being overlooked. We report nine cases presenting as primary, massive and protracted pleural effusions. All patients had evidence of Paragonimus spp. in the pleural fluid; one discharged an adult worm through a chest tube during treatment with praziquantel. In three cases, resolution of symptoms and pleural effusions could not be achieved, despite repeated fluid evacuation procedures and courses of praziquantel, which contradicts the widely accepted statement of paragonimiasis being self-limited and easy to cure. The disease should be considered in any case of elusive pleural effusion occurring in endemic areas.

Similitude of membrane helical coil with membrane serpentine tube for characteristics of high-pressure syngas: A review

NASA Astrophysics Data System (ADS)

Gaddamwar, Sagar. S.; Pawar, Anand N.; Naik, Pramod A.

2018-05-01

Heat exchangers remain one primary engineering methods besides this broad category of purposes including various waste heat recovery systems, power sectors, nuclear reactors. Natural convection is a method concerning heat transfer, during which flow of fluid occurs by density variations in the fluid occurring due to different temperature conditions. A fluid which encompasses a heat reservoir holds heat becomes light dense and rises. Operating fluid that is enclosing the high-temperature liquid remains frozen and later flows in to supplant it. Following this chilling liquid gets heated, and this method persists, resulting from convection flow. Forced convection into a heat exchanger is this movement of heat from one moving water to different stream through the surface from a pipe. The low-temperature liquid extracts heat of this comparatively high-temperature water because that flows along or over it.

Magnetic fluid control for viscous loss reduction of high-speed MRF brakes and clutches with well-defined fail-safe behavior

NASA Astrophysics Data System (ADS)

Güth, Dirk; Schamoni, Markus; Maas, Jürgen

2013-09-01

No-load losses within brakes and clutches based on magnetorheological fluids are unavoidable and represent a major barrier towards their wide-spread commercial adoption. Completely torque free rotation is not yet possible due to persistent fluid contact within the shear gap. In this paper, a novel concept is presented that facilitates the controlled movement of the magnetorheological fluid from an active, torque-transmitting region into an inactive region of the shear gap. This concept enables complete decoupling of the fluid engaging surfaces such that viscous drag torque can be eliminated. In order to achieve the desired effect, motion in the magnetorheological fluid is induced by magnetic forces acting on the fluid, which requires an appropriate magnetic circuit design. In this investigation, we propose a methodology to determine suitable magnetic circuit designs with well-defined fail-safe behavior. The magnetically induced motion of magnetorheological fluids is modeled by the use of the Kelvin body force, and a multi-physics domain simulation is performed to elucidate various transitions between an engaged and disengaged operating mode. The modeling approach is validated by captured high-speed video frames which show the induced motion of the magnetorheological fluid due to the magnetic field. Finally, measurements performed with a prototype actuator prove that the induced viscous drag torque can be reduced significantly by the proposed magnetic fluid control methodology.

Preparation of a cell line persistently infected with maedi/visna virus and production of viral antigens.

PubMed

Suzuki, Kazuya; Oguma, Keisuke; Sentsui, Hiroshi

2017-01-20

We attempted to prepare a cell line that produces maedi/visna virus (MVV) and is free of contamination by other viruses and mycoplasmas. Three cell lines, which originated from a sheep, goat and bat, were infected with MVV and passaged approximately every 5 days. The cultured cells were then subjected to polymerase chain reaction analysis for MVV provirus. As a result, a cell line persistently infected with MVV was established from ZZ-R cells, which originated from the fetal goat tongue. The 50-fold concentrated culture fluid formed a precipitation line against reference antiserum.

40 CFR 1065.720 - Liquefied petroleum gas.

Code of Federal Regulations, 2011 CFR

2011-07-01

... CONTROLS ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration....720—Test Fuel Specifications for Liquefied Petroleum Gas Item Value Reference procedure 1 Propane... test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a...

40 CFR 1065.720 - Liquefied petroleum gas.

Code of Federal Regulations, 2013 CFR

2013-07-01

... CONTROLS ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration....720—Test Fuel Specifications for Liquefied Petroleum Gas Item Value Reference procedure 1 Propane... test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a...

40 CFR 1065.720 - Liquefied petroleum gas.

Code of Federal Regulations, 2012 CFR

2012-07-01

... CONTROLS ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration....720—Test Fuel Specifications for Liquefied Petroleum Gas Item Value Reference procedure 1 Propane... test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a...

Anti-Human Immunodeficiency Virus Antibodies in the Cerebrospinal Fluid: Evidence of Early Treatment Impact on Central Nervous System Reservoir?

PubMed Central

Burbelo, Peter D; Price, Richard W; Hagberg, Lars; Hatano, Hiroyu; Spudich, Serena; Deeks, Steven G; Gisslén, Magnus

2018-01-01

Abstract Background Despite effective antiretroviral therapy (ART), human immunodeficiency virus (HIV) likely persists in the central nervous system (CNS) in treated individuals. We examined anti-HIV antibodies in cerebrospinal fluid (CSF) and blood as markers of persistence. Methods Human immunodeficiency virus antibodies were measured in paired CSF and serum before and after long-term treatment of chronic (n = 10) and early infection (n = 12), along with untreated early infection (n = 10). Results Treatment of chronic infection resulted in small reductions of anti-HIV antibodies in CSF and serum despite >10 years of suppressive ART. In untreated early infection, anti-HIV antibodies emerged in blood by day 30, whereas CSF antibodies reached similar levels 2 weeks later. Compared with long-term treatment of chronic infection, early ART initiation reduced CSF antibodies by 43-fold (P > .0001) and blood antibodies by 7-fold (P = .0003). Two individuals receiving pre-exposure prophylaxis and then ART early after infection failed to develop antibodies in CSF or blood, whereas CSF antibodies were markedly reduced in the Berlin patient. Conclusions To the extent that differential CSF and blood antibodies indicate HIV persistence, these data suggest a relative delay in establishment of the CNS compared with the systemic HIV reservoir that provides an opportunity for early treatment to have a greater impact on the magnitude of long-term CNS infection. PMID:29401308

Anti-Human Immunodeficiency Virus Antibodies in the Cerebrospinal Fluid: Evidence of Early Treatment Impact on Central Nervous System Reservoir?

PubMed

Burbelo, Peter D; Price, Richard W; Hagberg, Lars; Hatano, Hiroyu; Spudich, Serena; Deeks, Steven G; Gisslén, Magnus

2018-03-13

Despite effective antiretroviral therapy (ART), human immunodeficiency virus (HIV) likely persists in the central nervous system (CNS) in treated individuals. We examined anti-HIV antibodies in cerebrospinal fluid (CSF) and blood as markers of persistence. Human immunodeficiency virus antibodies were measured in paired CSF and serum before and after long-term treatment of chronic (n = 10) and early infection (n = 12), along with untreated early infection (n = 10). Treatment of chronic infection resulted in small reductions of anti-HIV antibodies in CSF and serum despite >10 years of suppressive ART. In untreated early infection, anti-HIV antibodies emerged in blood by day 30, whereas CSF antibodies reached similar levels 2 weeks later. Compared with long-term treatment of chronic infection, early ART initiation reduced CSF antibodies by 43-fold (P > .0001) and blood antibodies by 7-fold (P = .0003). Two individuals receiving pre-exposure prophylaxis and then ART early after infection failed to develop antibodies in CSF or blood, whereas CSF antibodies were markedly reduced in the Berlin patient. To the extent that differential CSF and blood antibodies indicate HIV persistence, these data suggest a relative delay in establishment of the CNS compared with the systemic HIV reservoir that provides an opportunity for early treatment to have a greater impact on the magnitude of long-term CNS infection.

Iatrogenic hypervitaminosis D as an unusual cause of persistent vomiting: a case report

PubMed Central

2014-01-01

Introduction Vitamin D is increasingly recognized to have several beneficial effects. Vitamin D deficiency is widely prevalent. Physicians often treat patients with high doses of vitamin D for various ailments without any monitoring for adverse effects and the prescribed doses often far exceed requirements resulting in toxicity. We present here a classic case of iatrogenic hypervitaminosis D, which presented with persistent vomiting and acute renal failure. Case presentation Here we present a case of a 45-year-old Asian Indian woman who presented to us with persistent vomiting the cause of which was iatrogenic hypervitaminosis D. She was treated with intravenous fluid, diuretics and calcitonin and had clinical improvement. Conclusions We suggest that in any patient presenting with persistent vomiting and hypercalcemia, particularly in the presence of normal parathyroid hormone, a diagnosis of overdose of vitamin D should be suspected. Its treatment not only alleviates symptoms but also prevents ongoing acute kidney injury. PMID:24571630

Distribution of fluids in the body of the centrifuged rat

NASA Technical Reports Server (NTRS)

Pitts, G. C.

1983-01-01

The effects of exposure to an elevated g-level throughout the period of rapid growth is investigated in a comparison of a group of female Sprague-Dawley rats centrifuged as adults with other groups centrifuged for prolonged intervals starting shortly after weaning. The fluid-solid composition of total body, heart, liver, gut, skin, and muscle for both study groups is compared with that of a control group. None of the changes as a result of centrifugation were truly persistent. The only increases in mass associated with centrifugation and the only responses to centrifugation per se were observed in the skin values.

Persistent hyperphagia in acquired brain injury; an observational case study of patients receiving inpatient rehabilitation.

PubMed

Rowell, Arleen M; Faruqui, Rafey A

2010-01-01

Morbid hunger or persistent hyperphagia is a relatively rare but potentially life threatening complication of acquired brain injury (ABI). This paper presents findings from an observational case study of patients with hyperphagia receiving inpatient neurobehavioural rehabilitation following their acquired brain injury. The case study has utilized dietetic and medical records of identified patients to confirm the persistent and serious nature of this presentation in order to extract important management principles. The findings confirmed that hyperphagia or morbid hunger posed potentially life-threatening health risks to the patient, primarily around weight control and fluid balance, and risks of aggression towards professional and family carers. Pharmacological or behaviour modification interventions were only partially successful in management of this presentation. The study identified a high need for environmental and cue exposure control in management of this condition.

New daily persistent headache.

PubMed

Evans, Randolph W

2003-08-01

New daily persistent headache (NDPH), which is the acute onset of headache within 3 days and is persistent for 15 days or more each month for at least 3 months, is a predominantly female heterogeneous subtype of chronic daily headache, typically with migraine features of unknown etiology. NDPH may be a presentation of other primary headaches such as new onset migraine, tension, or benign thunderclap headache. The headaches can be difficult to treat. The diagnosis is one of excluding the many secondary types or NDPH mimics, which is especially critical early in the course of the disease when a secondary etiology is more likely. NDPH mimics include postmeningitis headache, NDPH with medication rebound, neoplasms, temporal arteritis, chronic meningitis, chronic subdural hematoma, post-traumatic headaches, sphenoid sinusitis, hypertension, subarachnoid hemorrhage, low cerebrospinal fluid pressure syndrome, cervical artery dissections, pseudotumor cerebri without papilledema, and cerebral venous thrombosis.

Predictors of acute and persisting ischemic brain lesions in patients randomized to carotid stenting or endarterectomy.

PubMed

Rostamzadeh, Ayda; Zumbrunn, Thomas; Jongen, Lisa M; Nederkoorn, Paul J; Macdonald, Sumaira; Lyrer, Philippe A; Kappelle, L Jaap; Mali, Willem P Th M; Brown, Martin M; van der Worp, H Bart; Engelter, Stefan T; Bonati, Leo H

2014-02-01

We investigated predictors for acute and persisting periprocedural ischemic brain lesions among patients with symptomatic carotid stenosis randomized to stenting or endarterectomy in the International Carotid Stenting Study. We assessed acute lesions on diffusion-weighted imaging 1 to 3 days after treatment in 124 stenting and 107 endarterectomy patients and lesions persisting on fluid-attenuated inversion recovery after 1 month in 86 and 75 patients, respectively. Stenting patients had more acute (relative risk, 8.8; 95% confidence interval, 4.4-17.5; P<0.001) and persisting lesions (relative risk, 4.2; 95% confidence interval, 1.6-11.1; P=0.005) than endarterectomy patients. Acute lesion count was associated with age (by trend), male sex, and stroke as the qualifying event in stenting; high systolic blood pressure in endarterectomy; and white matter disease in both groups. The rate of conversion from acute to persisting lesions was lower in the stenting group (relative risk, 0.4; 95% confidence interval, 0.2-0.8; P=0.007), and was only predicted by acute lesion volume. Stenting caused more acute and persisting ischemic brain lesions than endarterectomy. However, the rate of conversion from acute to persisting lesions was lower in the stenting group, most likely attributable to lower acute lesion volumes. Clinical Trial Registration -URL: www.isrctn.org. Unique identifier: ISRCTN25337470.

Molecular aspect ratio and anchoring strength effects in a confined Gay-Berne liquid crystal

NASA Astrophysics Data System (ADS)

Cañeda-Guzmán, E.; Moreno-Razo, J. A.; Díaz-Herrera, E.; Sambriski, E. J.

2014-04-01

Phase diagrams for Gay-Berne (GB) fluids were obtained from molecular dynamics simulations for GB(2, 5, 1, 2) (i.e. short mesogens) and GB(3, 5, 1, 2) (i.e. long mesogens), which yield isotropic, nematic, and smectic-B phases. The long-mesogen fluid also yields the smectic-A phase. Ordered phases of the long-mesogen fluid form at higher temperatures and lower densities when compared to those of the short-mesogen fluid. The effect of confinement under weak and strong substrate couplings in slab geometry was investigated. Compared to the bulk, the isotropic-nematic transition does not shift in temprature significantly for the weakly coupled substrate in either mesogen fluid. However, the strongly coupled substrate shifts the transition to lower temperature. Confinement induces marked stratification in the short-mesogen fluid. This effect diminishes with distance from the substrate, yielding bulk-like behaviour in the slab central region. Fluid stratification is very weak for the long-mesogen fluid, but the strongly coupled substrate induces 'smectisation', an ordering effect that decays with distance. Orientation of the fluid on the substrate depends on the mesogen. There is no preferred orientation in a plane parallel to the substrate for the weakly coupled case. In the strongly coupled case, the mesogen orientation mimics that of adjacent fluid layers. Planar anchoring is observed with a broad distribution of orientations in the weakly coupled case. In the strongly coupled case, the distribution leans toward planar orientations for the short-mesogen fluid, while a marginal preference for tilting persists in the long-mesogen fluid.

Outcome of Full-Thickness Macular Hole Surgery in Choroideremia.

PubMed

Talib, Mays; Koetsier, Leonoor S; MacLaren, Robert E; Boon, Camiel J F

2017-07-21

The development of a macular hole is relatively common in retinal dystrophies eligible for gene therapy such as choroideremia. However, the subretinal delivery of gene therapy requires an uninterrupted retina to allow dispersion of the viral vector. A macular hole may thus hinder effective gene therapy. Little is known about the outcome of macular hole surgery and its possible beneficial and/or adverse effects on retinal function in patients with choroideremia. We describe a case of a unilateral full-thickness macular hole (FTMH) in a 45year-old choroideremia patient (c.1349_1349+2dup mutation in CHM gene) and its management. Pars plana vitrectomy with internal limiting membrane (ILM) peeling and 20% SF₆ gas tamponade was performed, and subsequent FTMH closure was confirmed at 4 weeks, 3 months and 5 months postoperatively. No postoperative adverse events occurred, and fixation stability improved on microperimetry from respectively 11% and 44% of fixation points located within a 1° and 2° radius, preoperatively, to 94% and 100% postoperatively. This case underlines that pars plana vitrectomy with ILM peeling and gas tamponade can successfully close a FTMH in choroideremia patients, with subsequent structural and functional improvement. Macular hole closure may be important for patients to be eligible for future submacular gene therapy.

Modeling Blood Flow in the Aorta.

ERIC Educational Resources Information Center

McConnell, Colin J.; Carmichael, Jonathan B.; DeMont, M. Edwin

1997-01-01

Presents an exercise to demonstrate two fundamental concepts of fluid mechanics: the Reynolds number and the Principle of Continuity. The exercise demonstrates flow in a major blood vessel, such as the aorta, with and without a stenosis. Students observe the transition from laminar to turbulent flow as well as downstream persistence of turbulence.…

Characterization of Viral Load, Viability and Persistence of Influenza A Virus in Air and on Surfaces of Swine Production Facilities.

PubMed

Neira, Victor; Rabinowitz, Peter; Rendahl, Aaron; Paccha, Blanca; Gibbs, Shawn G; Torremorell, Montserrat

2016-01-01

Indirect transmission of influenza A virus (IAV) in swine is poorly understood and information is lacking on levels of environmental exposure encountered by swine and people during outbreaks of IAV in swine barns. We characterized viral load, viability and persistence of IAV in air and on surfaces during outbreaks in swine barns. IAV was detected in pigs, air and surfaces from five confirmed outbreaks with 48% (47/98) of oral fluid, 38% (32/84) of pen railing and 43% (35/82) of indoor air samples testing positive by IAV RT-PCR. IAV was isolated from air and oral fluids yielding a mixture of subtypes (H1N1, H1N2 and H3N2). Detection of IAV RNA from air was sustained during the outbreaks with maximum levels estimated between 7 and 11 days from reported onset. Our results indicate that during outbreaks of IAV in swine, aerosols and surfaces in barns contain significant levels of IAV potentially representing an exposure hazard to both swine and people.

Penetration of chemicals into the oocyte, uterine fluid, and preimplantation blastocyst

PubMed Central

Fabro, Sergio

1978-01-01

Chemicals, including commonly used drugs (e.g., penicillin, meprobamate, pyridium, and mercaptomerin) penetrate and persist for some time in the ovarian follicular fluid at concentrations approximately similar to that of the serum. Information as to the penetration of chemicals into the granulosa cells and into the oocyte is scanty, although there are some indications that these structures are also permeable to foreign chemicals. Similarly, caffeine, nicotine, thiopental, salicylic acid, antipyrine, barbital, and isoniazid enter the uterine secretion and penetrate the preimplantation blastocyst of mice, rats and rabbits. The pattern of distribution of compounds among ovarian follicular fluid, uterine luminal fluid, blastocyst and plasma varies from compound to compound and appears to be related to the molecular weight and degree of ionization of the compound and differs in pregnant and nonpregnant animals. Thus, nicotine and DDT accumulate in the uterine luminal fluid of pregnant but not in that of nonpregnant rabbits. The penetration of foreign chemicals into the oocyte, uterine luminal fluid, and preimplantation blastocyst may exert adverse effects on fertilization, implantation, and/or further development of the conceptus. The possible toxicological importance of this process to eutherian reproduction is discussed. PMID:17539150

Analysis of organophosphate hydraulic fluids in U.S. Air force base soils

PubMed

David; Seiber

1999-04-01

Tri-aryl and tri-alkyl organophosphates (TAPs) have been used extensively as flame-retardant hydraulic fluids and fluid additives in commercial and military aircraft. Up to 80% of the consumption of these fluids has been estimated to be lost to unrecovered leakage. Tri-aryl phosphate components of these fluids are resistant to volatilization and solubilization in water, thus, their primary environmental fate pathway is sorption to soils. Environmental audits of military air bases generally do not include quantification of these compounds in soils. We have determined the presence and extent of TAP contamination in soil samples from several U.S. Air Force bases. Soils were collected, extracted, and analyzed using GC/FPD and GC/MS. Tricresyl phosphate was the most frequently found TAP in soil, ranging from 0.02 to 130 ppm. Other TAPs in soils included triphenyl phosphate and isopropylated triphenyl phosphate. Observations are made regarding the distribution, typical concentrations, persistence, and need for further testing of TAPs in soils at military installations. Additionally, GC and mass spectral data for these TAPs are presented, along with methods for their extraction, sample clean-up, and quantification.

Visualization of sneeze ejecta: steps of fluid fragmentation leading to respiratory droplets

NASA Astrophysics Data System (ADS)

Scharfman, B. E.; Techet, A. H.; Bush, J. W. M.; Bourouiba, L.

2016-02-01

Coughs and sneezes feature turbulent, multiphase flows that may contain pathogen-bearing droplets of mucosalivary fluid. As such, they can contribute to the spread of numerous infectious diseases, including influenza and SARS. The range of contamination of the droplets is largely determined by their size. However, major uncertainties on the drop size distributions persist. Here, we report direct observation of the physical mechanisms of droplet formation at the exit of the mouth during sneezing. Specifically, we use high-speed imaging to directly examine the fluid fragmentation at the exit of the mouths of healthy subjects. We reveal for the first time that the breakup of the fluid into droplets continues to occur outside of the respiratory tract during violent exhalations. We show that such breakup involves a complex cascade of events from sheets, to bag bursts, to ligaments, which finally break into droplets. Finally, we reveal that the viscoelasticity of the mucosalivary fluid plays an important role in delaying fragmentation by causing the merger of the droplet precursors that form along stretched filaments; thereby affecting the final drop size distribution farther downstream.

Fluid Mechanics in Sommerfeld's School

NASA Astrophysics Data System (ADS)

Eckert, Michael

2015-01-01

Sommerfeld's affiliation with fluid mechanics started when he began his career as an assistant of the mathematician Felix Klein at Göttingen. He always regarded fluid mechanics as a particular challenge. In 1904, he published a theory of hydrodynamic lubrication. Four years later, he conceived an approach for the analysis of flow instability (the Orr-Sommerfeld approach) as an attempt to account for the transition from laminar to turbulent flow. The onset of turbulence also became a major challenge for some of his pupils, in particular Ludwig Hopf and Fritz Noether. Both contributed considerably to elaborate the Orr-Sommerfeld theory. Heisenberg's doctoral work was another attempt in this quest. When Sommerfeld published his lectures on theoretical physics during World War II, he dedicated one of the six volumes to the mechanics of continuous media. With chapters on boundary layer theory and turbulence, it exceeded the scope of contemporary theoretical physics—revealing Sommerfeld's persistent appreciation of fluid mechanics. He resorted to Prandtl's Göttingen school of fluid mechanics in order to stay abreast of the rapid development of these specialties.

Effectiveness of treatments for severe sepsis: a prospective, multicenter, observational study.

PubMed

Ferrer, Ricard; Artigas, Antonio; Suarez, David; Palencia, Eduardo; Levy, Mitchell M; Arenzana, Angel; Pérez, Xose Luis; Sirvent, Josep-Maria

2009-11-01

Several Surviving Sepsis Campaign Guidelines recommendations are reevaluated. To analyze the effectiveness of treatments recommended in the sepsis guidelines. In a prospective observational study, we studied all adult patients with severe sepsis from 77 intensive care units. We recorded compliance with four therapeutic goals (central venous pressure 8 mm Hg or greater for persistent hypotension despite fluid resuscitation and/or lactate greater than 36 mg/dl, central venous oxygen saturation 70% or greater for persistent hypotension despite fluid resuscitation and/or lactate greater than 36 mg/dl, blood glucose greater than or equal to the lower limit of normal but less than 150 mg/dl, and inspiratory plateau pressure less than 30 cm H(2)O for mechanically ventilated patients) and four treatments (early broad-spectrum antibiotics, fluid challenge in the event of hypotension and/or lactate greater than 36 mg/dl, low-dose steroids for septic shock, drotrecogin alfa [activated] for multiorgan failure). The primary outcome measure was hospital mortality. The effectiveness of each treatment was estimated using propensity scores. Of 2,796 patients, 41.6% died before hospital discharge. Treatments associated with lower hospital mortality were early broad-spectrum antibiotic treatment (treatment within 1 hour vs. no treatment within first 6 hours of diagnosis; odds ratio, 0.67; 95% confidence interval, 0.50-0.90; P = 0.008) and drotrecogin alfa (activated) (odds ratio, 0.59; 95% confidence interval, 0.41-0.84; P = 0.004). Fluid challenge and low-dose steroids showed no benefits. In severe sepsis, early administration of broad-spectrum antibiotics in all patients and administration of drotrecogin alfa (activated) in the most severe patients reduce mortality.

Investigation of persistent Multiplets at the EGS reservoir of Soultz-Sous-Forêts, France

NASA Astrophysics Data System (ADS)

Lengliné, O.; Cauchie, L.; Schmittbuhl, J.

2017-12-01

During the exploitation of geothermal reservoirs, abundant seismicity is generally observed, especially during phases of hydraulic stimulations. The induced seismicity at the Enhanced Geothermal System of Soultz-Sous-Forêts in France, has been thoroughly studied over the years of exploitation. The mechanism at its origin has been related to both fluid pressure increases during stimulation and aseismic creeping movements. The fluid-induced seismic events often exhibit a high degree of similarity and the mechanism at the origin of these repeated events is thought to be associated with slow slip process where asperities on the rupture zone act several times.To have a better understanding of the mechanisms associated with such events and on the damaged zones involved during the hydraulic stimulations, we investigate the behavior of the multiplets and their persistent nature over several water injection intervals. For this purpose, we analyzed large datasets recorded from a borehole seismic network for several water injection periods (1993, 2000). For each stimulation interval, thousands of events are recorded at depth. We detected the events using a STA/LTA approach and classified them into families of comparable waveforms using an approach based on cross-correlation analysis. Classification of the seismic events is then improved depending on their location within the multiplets. For this purpose, inter-event distances within multiplets are examined and determined from cross-correlation analysis between pairs of events. These distances are then compared to the source dimensions derived from the estimation of the corner frequencies estimation. The multiplets properties (location, events size) are then investigated within and over several hydraulic tests. Hopefully these steps will lead to increase the knowledge on the repetitive nature of these events and the investigation of their persistence will outline the heterogeneities of the structures (regional stress perturbations, fluid flow channeling) regularly involved during the different stimulations.

Dispersion in Fractures with Ramified Dissolution Patterns

NASA Astrophysics Data System (ADS)

Xu, Le; Marks, Benjy; Toussaint, Renaud; Flekkøy, Eirik G.; Måløy, Knut J.

2018-04-01

The injection of a reactive fluid into an open fracture may modify the fracture surface locally and create a ramified structure around the injection point. This structure will have a significant impact on the dispersion of the injected fluid due to increased permeability, which will introduce large velocity fluctuations into the fluid. Here, we have injected a fluorescent tracer fluid into a transparent artificial fracture with such a ramified structure. The transparency of the model makes it possible to follow the detailed dispersion of the tracer concentration. The experiments have been compared to two dimensional (2D) computer simulations which include both convective motion and molecular diffusion. A comparison was also performed between the dispersion from an initially ramified dissolution structure and the dispersion from an initially circular region. A significant difference was seen both at small and large length scales. At large length scales, the persistence of the anisotropy of the concentration distribution far from the ramified structure is discussed with reference to some theoretical considerations and comparison with simulations.

Thin-film Faraday patterns in three dimensions

NASA Astrophysics Data System (ADS)

Richter, Sebastian; Bestehorn, Michael

2017-04-01

We investigate the long time evolution of a thin fluid layer in three spatial dimensions located on a horizontal planar substrate. The substrate is subjected to time-periodic external vibrations in normal and in tangential direction with respect to the plane surface. The governing partial differential equation system of our model is obtained from the incompressible Navier-Stokes equations considering the limit of a thin fluid geometry and using the long wave lubrication approximation. It includes inertia and viscous friction. Numerical simulations evince the existence of persistent spatially complex surface patterns (periodic and quasiperiodic) for certain superpositions of two vertical excitations and initial conditions. Additional harmonic lateral excitations cause deformations but retain the basic structure of the patterns. Horizontal ratchet-shaped forces lead to a controllable lateral movement of the fluid. A Floquet analysis is used to determine the stability of the linearized system.

Intraventricular catheter placement by electromagnetic navigation safely applied in a paediatric major head injury patient.

PubMed

Aufdenblatten, Christoph Alexander; Altermatt, Stefan

2008-09-01

In the management of severe head injuries, the use of intraventricular catheters for intracranial pressure (ICP) monitoring and the option of cerebrospinal fluid drainage is gold standard. In children and adolescents, the insertion of a cannula in a compressed ventricle in case of elevated intracranial pressure is difficult; therefore, a pressure sensor is placed more often intraparenchymal as an alternative option. In cases of persistent elevated ICP despite maximal brain pressure management, the use of an intraventricular monitoring device with the possibility of cerebrospinal fluid drainage is favourable. We present the method of intracranial catheter placement by means of an electromagnetic navigation technique.

[Management of corneal hydrops using air and micro-punctures].

PubMed

Campos Polo, R; Chacón Iglesias, J; Gamazo Carrasco, M; Mencía Bartolomé, J M; Solana Fajardo, J; García Guisado, D; Fernández Miranda, C; Bueno Álvarez-Arenas, J; Sánchez Trancón, Á; García Ardoy, E

2015-04-01

A 22-year- old woman with an acute hydrops and Descemet membrane detachment was managed by intracameral air injection combined with multiple corneal stromal venting incisions for the drainage of intrastromal fluid. No intraoperative complications were encountered, and the intrastromal fluid was resolved over 2 weeks. Acute corneal hydrops is a significant complication of keratoconus. If not treated, resolution usually occurs over a period of 2-4 months. The persistent oedema can cause complications, such as corneal neovascularisation, infection and corneal perforation. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Precambrian Lunar Volcanic Protolife

PubMed Central

Green, Jack

2009-01-01

Five representative terrestrial analogs of lunar craters are detailed relevant to Precambrian fumarolic activity. Fumarolic fluids contain the ingredients for protolife. Energy sources to derive formaldehyde, amino acids and related compounds could be by flow charging, charge separation and volcanic shock. With no photodecomposition in shadow, most fumarolic fluids at 40 K would persist over geologically long time periods. Relatively abundant tungsten would permit creation of critical enzymes, Fischer-Tropsch reactions could form polycyclic aromatic hydrocarbons and soluble volcanic polyphosphates would enable assembly of nucleic acids. Fumarolic stimuli factors are described. Orbital and lander sensors specific to protolife exploration including combined Raman/laser-induced breakdown spectrocsopy are evaluated. PMID:19582224

Subacute sclerosing panencephalitis in a child with recurrent febrile seizures.

PubMed

Kartal, Ayşe; Çıtak Kurt, Ayşegül Neşe; Hirfanoğlu, Tuğba; Aydın, Kürşad; Serdaroğlu, Ayşe

2015-01-01

Subacute sclerosing panencephalitis (SSPE) is a devastating disease of the central nervous system (CNS) caused by persistent mutant measles virus infection. The diagnosis of SSPE is based on characteristic clinical and EEG findings and demonstration of elevated antibody titres against measles in cerebrospinal fluid. Subacute sclerosing panencephalitis can have atypical clinical features at the onset. Herein, we report an unusual case of subacute sclerosing panencephalitis in a child with recurrent febrile seizures. The disease progressed with an appearance of myoclonic jerks, periodic high amplitude generalized complexes on EEG, and elevated titers of measles antibodies in cerebrospinal fluid leading to the final diagnosis of subacute sclerosing panencephalitis.

Subacute Sclerosing Panencephalitis in a Child with Recurrent Febrile Seizures

PubMed Central

Kartal, Ayşe; Çıtak Kurt, Ayşegül Neşe; Hirfanoğlu, Tuğba; Aydın, Kürşad; Serdaroğlu, Ayşe

2015-01-01

Subacute sclerosing panencephalitis (SSPE) is a devastating disease of the central nervous system (CNS) caused by persistent mutant measles virus infection. The diagnosis of SSPE is based on characteristic clinical and EEG findings and demonstration of elevated antibody titres against measles in cerebrospinal fluid. Subacute sclerosing panencephalitis can have atypical clinical features at the onset. Herein, we report an unusual case of subacute sclerosing panencephalitis in a child with recurrent febrile seizures. The disease progressed with an appearance of myoclonic jerks, periodic high amplitude generalized complexes on EEG, and elevated titers of measles antibodies in cerebrospinal fluid leading to the final diagnosis of subacute sclerosing panencephalitis. PMID:25802788

Genome sequences of seven foot-and-mouth disease virus isolates collected from serial samples from one persistently infected carrier cow in Vietnam

USDA-ARS?s Scientific Manuscript database

Several FMDV carrier cattle were identified in Vietnam by recovery of infectious virus from oropharyngeal fluid. This report contains the first near-complete genome sequences of seven viruses isolated from a single carrier animal over the course of one year. Understanding within-host viral evolution...

Fundamental Research in Engineering Education. Identifying and Repairing Student Misconceptions in Thermal and Transport Science: Concept Inventories and Schema Training Studies

ERIC Educational Resources Information Center

Miller, Ronald L.; Streveler, Ruth A.; Yang, Dazhi; Roman, Aidsa I. Santiago

2011-01-01

This paper summarizes progress on two related lines of chemical engineering education research: 1) identifying persistent student misconceptions in thermal and transport science (fluid mechanics, heat transfer, and thermodynamics); and, 2) developing a method to help students repair these misconceptions. Progress on developing the Thermal and…

Saffold Virus Type 3 (SAFV-3) Persists in HeLa Cells

PubMed Central

Himeda, Toshiki; Hosomi, Takushi; Okuwa, Takako; Muraki, Yasushi; Ohara, Yoshiro

2013-01-01

Saffold virus (SAFV) was identified as a human cardiovirus in 2007. Although several epidemiological studies have been reported, they have failed to provide a clear picture of the relationship between SAFV and human diseases. SAFV genotype 3 has been isolated from the cerebrospinal fluid specimen of patient with aseptic meningitis. This finding is of interest since Theiler’s murine encephalomyelitis virus (TMEV), which is the closely related virus, is known to cause a multiple sclerosis-like syndrome in mice. TMEV persistently infects in mouse macrophage cells in vivo and in vitro, and the viral persistence is essential in TMEV-induced demyelinating disease. The precise mechanism(s) of SAFV infection still remain unclear. In order to clarify the SAFV pathogenicity, in the present study, we studied the possibilities of the in vitro persistent infection of SAFV. The two distinct phenotypes of HeLa cells, HeLa-N and HeLa-R, were identified. In these cells, the type of SAFV-3 infection was clearly different. HeLa-N cells were lyticly infected with SAFV-3 and the host suitable for the efficient growth. On the other hand, HeLa-R cells were persistently infected with SAFV-3. In addition, the SAFV persistence in HeLa-R cells is independent of type I IFN response of host cells although the TMEV persistence in mouse macrophage cells depends on the response. Furthermore, it was suggested that SAFV persistence may be influenced by the expression of receptor(s) for SAFV infection on the host cells. The present findings on SAFV persistence will provide the important information to encourage the research of SAFV pathogenicity. PMID:23308162

Fluid dynamics following flow shut-off in bottle filling

NASA Astrophysics Data System (ADS)

Thete, Sumeet; Appathurai, Santosh; Gao, Haijing; Basaran, Osman

2012-11-01

Bottle filling is ubiquitous in industry. Examples include filling of bottles with shampoos and cleaners, engine oil and pharmaceuticals. In these examples, fluid flows out of a nozzle to fill bottles in an assembly line. Once the required volume of fluid has flowed out of the nozzle, the flow is shut off. However, an evolving fluid thread or string may remain suspended from the nozzle following flow shut-off and persist. This stringing phenomenon can be detrimental to a bottle filling operation because it can adversely affect line speed and filling accuracy by causing uncertainty in fill volume, product loss and undesirable marring of the bottles' exterior surfaces. The dynamics of stringing are studied numerically primarily by using the 1D, slender-jet approximation of the flow equations. A novel feature entails development and use of a new boundary condition downstream of the nozzle exit to expedite the computations. While the emphasis is on stringing of Newtonian fluids and use of 1D approximations, results will also be presented for situations where (a) the fluids are non-Newtonian and (b) the full set of equations are solved without invoking the 1D approximation. Phase diagrams will be presented that identify conditions for which stringing can be problematic.

Physiologic mechanisms of circulatory and body fluid losses in weightlessness identified by mathematical modeling

NASA Technical Reports Server (NTRS)

Simanonok, K. E.; Srinivasan, R. S.; Charles, J. B.

1993-01-01

Central volume expansion due to fluid shifts in weightlessness is believed to activate adaptive reflexes which ultimately result in a reduction of the total circulating blood volume. However, the flight data suggests that a central volume overdistention does not persist, in which case some other factor or factors must be responsible for body fluid losses. We used a computer simulation to test the hypothesis that factors other than central volume overdistention are involved in the loss of blood volume and other body fluid volumes observed in weightlessness and in weightless simulations. Additionally, the simulation was used to identify these factors. The results predict that atrial volumes and pressures return to their prebedrest baseline values within the first day of exposure to head down tilt (HDT) as the blood volume is reduced by an elevated urine formation. They indicate that the mechanisms for large and prolonged body fluid losses in weightlessness is red cell hemoconcentration that elevates blood viscosity and peripheral resistance, thereby lowering capillary pressure. This causes a prolonged alteration of the balance of Starling forces, depressing the extracellular fluid volume until the hematocrit is returned to normal through a reduction of the red cell mass, which also allows some restoration of the plasma volume. We conclude that the red cell mass becomes the physiologic driver for a large 'undershoot' of the body fluid volumes after the normalization of atrial volumes and pressures.

Selected Organochlorines in Human Blood and Urine in the South of the Russian Far East.

PubMed

Tsygankov, Vasiliy Yu; Khristoforova, Nadezhda K; Lukyanova, Olga N; Boyarova, Margarita D; Kiku, Pavel F; Yarygina, Marina V

2017-10-01

The trace OCP concentrations, such as α-, β-, and γ-HCH, DDT and its metabolites (DDD and DDE) in blood and urine of residents from the south of the Russian Far East was revealed. A large range of OCPs was found in the urine: α- and γ-isomers of HCH, DDT and DDE. The only β-HCH was detected in the blood; this indicates its persistence and the difficulty of excretion this substance from the organism. The total trace OCP concentration, found in the biological fluids of residents of the south of the Russian Far East, providing further evidence that these organic contaminants persist in the environment.

Familial microscopic hematuria caused by hypercalciuria and hyperuricosuria.

PubMed

Praga, M; Alegre, R; Hernández, E; Morales, E; Domínguez-Gil, B; Carreño, A; Andrés, A

2000-01-01

We report 12 patients belonging to five different families in whom persistent isolated microhematuria was associated with hypercalciuria and/or hyperuricosuria. Four patients had episodes of gross hematuria, three patients had passed renal stones, and a history of nephrolithiasis was obtained in four of the families (80%). Calcium oxalate and uric acid crystals were commonly observed in the urine sediments. Urinary erythrocytes had a normal appearance on phase-microscopic examination. Reduction of calciuria and uricosuria by thiazide diuretics, allopurinol, forced fluid intake, and dietetic measures led to a persistent normalization of urine sediment with complete disappearance of hematuria. Determination of calcium and uric acid urinary excretions should be included in the study of familial hematuria.

Prognostic implications of fluid balance in ST elevation myocardial infarction complicated by cardiogenic shock.

PubMed

Arbel, Yaron; Mass, Ronen; Ziv-Baran, Tomer; Khoury, Shafik; Margolis, Gilad; Sadeh, Ben; Flint, Nir; Ben-Shoshan, Jeremy; Finn, Talya; Keren, Gad; Shacham, Yacov

2017-08-01

Positive fluid balance has been associated with adverse outcomes in patients admitted to general intensive care units. We analysed the relationship between a positive fluid balance and its persistence over time in terms of in-hospital outcomes among ST elevation myocardial infarction (STEMI) patients complicated by cardiogenic shock. We retrospectively studied fluid intake and output for 96 hours following hospital admission in 48 consecutive adult patients with STEMI complicated by cardiogenic shock, all undergoing primary angioplasty. Daily and accumulated fluid balance was registered at up to 96 hours following admission. The cohort was stratified into two groups based on the presence or absence of positive fluid balance on day 4. Patients' records were assessed for in-hospital adverse outcomes, as well as 30-day all-cause mortality. A positive fluid balance was present in 19/48 patients (40%). Patients with positive fluid balance were older and more likely to be treated by intra-aortic balloon counter-pulsation and antibiotics. These patients were more likely to develop acute kidney injury and to need new intubation and were less likely to have renal function recovery as well as successful weaning from mechanical ventilation ( p < 0.05 for all). Patients with positive fluid balance had higher 30-day mortality (68% vs. 10%; p < 0.001). In a multivariate Cox regression model, for every 1-L increase in positive fluid balance, the adjusted risk for 30-day mortality increased by 24% (hazard ratio: 1.24, 95% confidence interval: 1.07-1.42; p = 0.003). A positive fluid balance was strongly associated with higher 30-day mortality in STEMI complicated by cardiogenic shock.

Partitioning of Metals Throughout a Winter Storm-Generated Fluid Mud Event, Atchafalaya Shelf, Louisiana

NASA Astrophysics Data System (ADS)

Clark, F. R.; McKee, B. A.; Duncan, D. D.

2002-12-01

Particulate and dissolved phases of a suite of metals and radionuclides were analyzed in fluid mud samples collected during a time series. This time series was taken during the passage of a winter storm on the Atchafalaya Shelf off the coast of Louisiana. The shelf receives an estimated 30% of the flow of the Mississippi River from its distributary, the Atchafalaya River. This input contributes a high sediment load to the shelf. Frequent winter storms provide shear stress to resuspend sediments and form fluid mud. Samples of fluid mud and overlying water were collected every two hours for 56 hours. Meteorological data as well as turbidity measurements by OBS were collected throughout the study. Bottom sediments were also collected before and after the time series. Partitioning effects were investigated on Be7, Th234, and Pb210 by gamma spectroscopy. These effects were also studied on several redox-sensitive metals, including Fe, Mn, Mo, Te, Re, U, Al, Ti, and V by ICP-MS analysis. Preliminary results indicate a rapid establishment of reducing conditions in fluid mud immediately overlying the seabed. These conditions persist until the suspended sediments in the fluid mud settle, and the fluid mud dissipates. The recurrence of storm front passages and their subsequent fluid mud formation cause repeated cycling from oxic to suboxic conditions in these coastal bottom waters. This redox cycling could potentially alter the fates of redox-sensitive metals, especially those associated with metal oxide carrier phases.

Dynamics of Active Microfilaments

NASA Astrophysics Data System (ADS)

Ling, Feng; Guo, Hanliang; Kanso, Eva

2017-11-01

Soft elastic filaments are ubiquitous in natural and artificial systems at various length scales, and their interactions within and between filaments and their environments provide a persistent source of curiosity due to both the complexity of their behaviors and the relative mathematical simplicity of their structures. Specifically, a deeper understanding of the dynamic characteristics of microscopic filaments in viscous fluids is relevant to many biophysical and physiological processes. Here we start with the Cosserat model that allows all six possible modes of deformation for an elastic rod, and focus on the case of inextensible filaments submerged in viscous fluids by ignoring inertial effects and using local resistive force theory for fluid-filament interactions. We verify our simulations against special analytic solutions and present some results on the active internal control of cilia and flagella motion. We conclude by commenting on the utility of this general framework for studying other cellular and sub-cellular physical processes such as systems involving protein filaments.

CFD validation experiments at McDonnell Aircraft Company

NASA Technical Reports Server (NTRS)

Verhoff, August

1987-01-01

Information is given in viewgraph form on computational fluid dynamics (CFD) validation experiments at McDonnell Aircraft Company. Topics covered include a high speed research model, a supersonic persistence fighter model, a generic fighter wing model, surface grids, force and moment predictions, surface pressure predictions, forebody models with 65 degree clipped delta wings, and the low aspect ratio wing/body experiment.

May turbulence and fossil turbulence lead to life in the universe?

NASA Astrophysics Data System (ADS)

Gibson, Carl H.

2013-01-01

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than all the other forces that tend to damp the eddies out. Fossil turbulence is a perturbation produced by turbulence that persists after the fluid ceases to be turbulent at the scale of the perturbation. Because vorticity is produced at small scales, turbulence cascades from small scales to large, providing a consistent physical basis for Kolmogorovian universal similarity laws. Oceanic and astrophysical mixing and diffusion are dominated by fossil turbulence and fossil turbulent waves. Observations from space telescopes show turbulence existed in the beginning of the universe and that its fossils still persist. Fossils of big bang turbulence include a preferred large-scale spin direction, large scale microwave temperature anisotropy patterns, and the dominant dark matter of all galaxies; that is, clumps of ~10^12 frozen hydrogen earth-mass planets that make stars and globular-star-clusters when gravitationally agitated. When the planets were hot gas, we can speculate that they hosted the formation of the first life in a seeded cosmic organic-chemical soup of hot- water oceans as planets merged to form and over-feed the first stars.

Turbulence and fossil turbulence lead to life in the universe

NASA Astrophysics Data System (ADS)

Gibson, Carl H.

2013-07-01

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than all the other forces that tend to damp the eddies out. Fossil turbulence is a perturbation produced by turbulence that persists after the fluid ceases to be turbulent at the scale of the perturbation. Because vorticity is produced at small scales, turbulence must cascade from small scales to large, providing a consistent physical basis for Kolmogorovian universal similarity laws. Oceanic and astrophysical mixing and diffusion are dominated by fossil turbulence and fossil turbulent waves. Observations from space telescopes show turbulence and vorticity existed in the beginning of the universe and that their fossils persist. Fossils of big bang turbulence include spin and the dark matter of galaxies: clumps of ∼1012 frozen hydrogen planets that make globular star clusters as seen by infrared and microwave space telescopes. When the planets were hot gas, they hosted the formation of life in a cosmic soup of hot-water oceans as they merged to form the first stars and chemicals. Because spontaneous life formation according to the standard cosmological model is virtually impossible, the existence of life falsifies the standard cosmological model.

Turbulence and Fossil Turbulence lead to Life in the Universe

NASA Astrophysics Data System (ADS)

Gibson, Carl H.

2012-03-01

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than all the other forces that tend to damp the eddies out. Fossil turbulence is a perturbation produced by turbulence that persists after the fluid ceases to be turbulent at the scale of the perturbation. Because vorticity is produced at small scales, turbulence must cascade from small scales to large, providing a consistent physical basis for Kolmogorovian universal similarity laws. Oceanic and astrophysical mixing and diffusion are dominated by fossil turbulence and fossil turbulent waves. Observations from space telescopes show turbulence and vorticity existed in the beginning of the universe and that their fossils persist. Fossils of big bang turbulence include spin and the dark matter of galaxies: clumps of ~ 1012 frozen hydrogen planets that make globular star clusters as seen by infrared and microwave space telescopes. When the planets were hot gas, they hosted the formation of life in a cosmic soup of hot- water oceans as they merged to form the first stars and chemicals. Because spontaneous life formation according to the standard cosmological model is virtually impossible, the existence of life falsifies the standard cosmological model.

Boiling-induced formation of colloidal gold in black smoker hydrothermal fluids

USGS Publications Warehouse

Gartman, Amy; Hannington, Mark; Jamieson, John W.; Peterkin, Ben; Garbe-Schönberg, Dieter; Findlay, Alyssa J; Fuchs, Sebastian; Kwasnitschka, Tom

2017-01-01

Gold colloids occur in black smoker fluids from the Niua South hydrothermal vent field, Lau Basin (South Pacific Ocean), confirming the long-standing hypothesis that gold may undergo colloidal transport in hydrothermal fluids. Six black smoker vents, varying in temperature from 250 °C to 325 °C, were sampled; the 325 °C vent was boiling at the time of sampling and the 250 °C fluids were diffusely venting. Native gold particles ranging from <50 nm to 2 µm were identified in 4 of the fluid samples and were also observed to precipitate on the sampler during collection from the boiling vent. Total gold concentrations (dissolved and particulate) in the fluid samples range from 1.6 to 5.4 nM in the high-temperature, focused flow vents. Although the gold concentrations in the focused flow fluids are relatively high, they are lower than potential solubilities prior to boiling and indicate that precipitation was boiling induced, with sulfide lost upon boiling to exsolution and metal sulfide formation. Gold concentrations reach 26.7 nM in the 250 °C diffuse flow sample, and abundant native gold particles were also found in the fluids and associated sulfide chimney and are interpreted to be a product of colloid accumulation and growth following initial precipitation upon boiling. These results indicate that colloid-driven precipitation as a result of boiling, the persistence of colloids after boiling, and the accumulation of colloids in diffuse flow fluids are important mechanisms for the enrichment of gold in seafloor hydrothermal systems.

Morphogenetic Implications of Peristalsis-Driven Fluid Flow in the Embryonic Lung

PubMed Central

Bokka, Kishore K.; Jesudason, Edwin C.; Lozoya, Oswaldo A.; Guilak, Farshid; Warburton, David; Lubkin, Sharon R.

2015-01-01

Epithelial organs are almost universally secretory. The lung secretes mucus of extremely variable consistency. In the early prenatal period, the secretions are of largely unknown composition, consistency, and flow rates. In addition to net outflow from secretion, the embryonic lung exhibits transient reversing flows from peristalsis. Airway peristalsis (AP) begins as soon as the smooth muscle forms, and persists until birth. Since the prenatal lung is liquid-filled, smooth muscle action can transport fluid far from the immediately adjacent tissues. The sensation of internal fluid flows has been shown to have potent morphogenetic effects, as has the transport of morphogens. We hypothesize that these effects play an important role in lung morphogenesis. To test these hypotheses in a quantitative framework, we analyzed the fluid-structure interactions between embryonic tissues and lumen fluid resulting from peristaltic waves that partially occlude the airway. We found that if the airway is closed, fluid transport is minimal; by contrast, if the trachea is open, shear rates can be very high, particularly at the stenosis. We performed a parametric analysis of flow characteristics' dependence on tissue stiffnesses, smooth muscle force, geometry, and fluid viscosity, and found that most of these relationships are governed by simple ratios. We measured the viscosity of prenatal lung fluid with passive bead microrheology. This paper reports the first measurements of the viscosity of embryonic lung lumen fluid. In the range tested, lumen fluid can be considered Newtonian, with a viscosity of 0.016 ± 0.008 Pa-s. We analyzed the interaction between the internal flows and diffusion and conclude that AP has a strong effect on flow sensing away from the tip and on transport of morphogens. These effects may be the intermediate mechanisms for the enhancement of branching seen in occluded embryonic lungs. PMID:26147967

Central diabetes insipidus: alert for dehydration in very low birth weight infants during the neonatal period. A case report.

PubMed

Ferlin, Maria Lúcia Silveira; Sales, Débora Simone; Celini, Fábia Pereira Martins; Martinelli Junior, Carlos Eduardo

2015-02-01

Central diabetes insipidus (CDI) is a rare cause of hypernatremia during the neonatal period. The diagnosis is particularly difficult in very low birth weight (VLBW) newborns. We report on a preterm newborn who presented CDI soon after birth. On the third day of life, signs of dehydration were present despite normal fluid supply. The diuresis rate was 4.4 ml/kg/h. Although the fluid supply was then increased, the dehydration continued, with hypernatremia, normal glycemia, diuresis of 7.4 ml/kg/h and urine density of 1005 mOsmol/l. Thus, a diagnostic hypothesis of diabetes insipidus was raised. A test with a nasal vasopressin analogue (dDAVP) was performed and CDI was confirmed. Reduction of the fluid supply became possible through appropriate treatment. The diagnosis of CDI is rarely made during the neonatal period, especially in VLBW newborns, because of the difficulty in detecting elevated diuresis. Persistent hypernatremia, usually accompanied by hyperthermia despite abundant fluid supply, weight loss and low urine osmolality are important signs of alert.

Persistent Borrelia Infection in Patients with Ongoing Symptoms of Lyme Disease.

PubMed

Middelveen, Marianne J; Sapi, Eva; Burke, Jennie; Filush, Katherine R; Franco, Agustin; Fesler, Melissa C; Stricker, Raphael B

2018-04-14

Lyme disease is a tickborne illness that generates controversy among medical providers and researchers. One of the key topics of debate is the existence of persistent infection with the Lyme spirochete, Borrelia burgdorferi , in patients who have been treated with recommended doses of antibiotics yet remain symptomatic. Persistent spirochetal infection despite antibiotic therapy has recently been demonstrated in non-human primates. We present evidence of persistent Borrelia infection despite antibiotic therapy in patients with ongoing Lyme disease symptoms. In this pilot study, culture of body fluids and tissues was performed in a randomly selected group of 12 patients with persistent Lyme disease symptoms who had been treated or who were being treated with antibiotics. Cultures were also performed on a group of ten control subjects without Lyme disease. The cultures were subjected to corroborative microscopic, histopathological and molecular testing for Borrelia organisms in four independent laboratories in a blinded manner. Motile spirochetes identified histopathologically as Borrelia were detected in culture specimens, and these spirochetes were genetically identified as Borrelia burgdorferi by three distinct polymerase chain reaction (PCR)-based approaches. Spirochetes identified as Borrelia burgdorferi were cultured from the blood of seven subjects, from the genital secretions of ten subjects, and from a skin lesion of one subject. Cultures from control subjects without Lyme disease were negative for Borrelia using these methods. Using multiple corroborative detection methods, we showed that patients with persistent Lyme disease symptoms may have ongoing spirochetal infection despite antibiotic treatment, similar to findings in non-human primates. The optimal treatment for persistent Borrelia infection remains to be determined.

Intra-peritoneal chronic loculation in peritoneal dialysis patients - a new medical management approach.

PubMed

Mitoiu, Dan; David, Cristiana; Peride, Ileana; Niculae, Andrei; Mureşan, Alin; Ciocâlteu, Alexandru; Geavlete, Bogdan Florin; Checheriţă, Ionel Alexandru

2014-01-01

Peritoneal dialysis (PD) limitation as renal replacement therapy is mostly due to peritonitis and complications. Formation and persistence of intra-abdominal loculations is often under-diagnosed. Encapsulated peritoneal sclerosis (EPS) is a life-threatening complication, but malnutrition, recurrent peritonitis and early membrane failure are insidious enemies that need to be emphasized. It is important to highlight the persistence of intra-abdominal fluid collection after clinical resolution of peritonitis in PD patients and to indicate a new medical management approach for an early diagnosis. During five years, we selected PD peritonitis cases followed by a six months interval free of infections. Ninety-seven subjects were followed at six months and one year after the first peritonitis. Tomography had been performed to patients presenting a positive inflammatory state without a specific infectious cause. Subjects presenting documented localized fluid collection (31 cases) were divided into: drug-treated group and those undergoing laparoscopy by a new surgery technique (seven patients); a comparison regarding the clinical state and biohumoral parameters was assessed in both groups. The prevalence of intra-abdominal loculation following an apparent resolved peritonitis was high (31.9%). The cases undergoing laparoscopy presented a better evolution - improved clinical status (p=0.001), higher hemoglobin values (p=0.06), significant lower doses of erythropoietin requirement (p=0.03), improved dialysis adequacy (p=0.005) and inflammatory state. In cases with confirmed fluid encapsulated loculation, an active attitude (screening imaging protocol and laparoscopic exploration) appears to be mandatory, decreasing the risk of EPS, a serious complication which pathology and treatment are incompletely understood.

NK cells contribute to persistent airway inflammation and AHR during the later stage of RSV infection in mice.

PubMed

Long, Xiaoru; Xie, Jun; Zhao, Keting; Li, Wei; Tang, Wei; Chen, Sisi; Zang, Na; Ren, Luo; Deng, Yu; Xie, Xiaohong; Wang, Lijia; Fu, Zhou; Liu, Enmei

2016-10-01

RSV can lead to persistent airway inflammation and AHR and is intimately associated with childhood recurrent wheezing and asthma, but the underlying mechanisms remain unclear. There are high numbers of NK cells in the lung, which not only play important roles in the acute stage of RSV infection, but also are pivotal in regulating the pathogenesis of asthma. Therefore, in this study, we assumed that NK cells might contribute to persistent airway disease during the later stage of RSV infection. Mice were killed at serial time points after RSV infection to collect samples. Leukocytes in bronchoalveolar lavage fluid (BALF) were counted, lung histopathology was examined, and airway hyperresponsiveness (AHR) was measured by whole-body plethysmography. Cytokines were detected by ELISA, and NK cells were determined by flow cytometry. Rabbit anti-mouse asialo-GM-1 antibodies and resveratrol were used to deplete or suppress NK cells. Inflammatory cells in BALF, lung tissue damage and AHR were persistent for 60 days post-RSV infection. Type 2 cytokines and NK cells were significantly increased during the later stage of infection. When NK cells were decreased by the antibodies or resveratrol, type 2 cytokines, the persistent airway inflammation and AHR were all markedly reduced. NK cells can contribute to the RSV-associated persistent airway inflammation and AHR at least partially by promoting type 2 cytokines. Therefore, therapeutic targeting of NK cells may provide a novel approach to alleviating the recurrent wheezing subsequent to RSV infection.

New Numerical Approaches To thermal Convection In A Compositionally Stratified Fluid

NASA Astrophysics Data System (ADS)

Puckett, E. G.; Turcotte, D. L.; Kellogg, L. H.; Lokavarapu, H. V.; He, Y.; Robey, J.

2016-12-01

Seismic imaging of the mantle has revealed large and small scale heterogeneities in the lower mantle; specifically structures known as large low shear velocity provinces (LLSVP) below Africa and the South Pacific. Most interpretations propose that the heterogeneities are compositional in nature, differing from the overlying mantle, an interpretation that would be consistent with chemical geodynamic models. The LLSVP's are thought to be very old, meaning they have persisted thoughout much of Earth's history. Numerical modeling of persistent compositional interfaces present challenges to even state-of-the-art numerical methodology. It is extremely difficult to maintain sharp composition boundaries which migrate and distort with time dependent fingering without compositional diffusion and / or artificial diffusion. The compositional boundary must persist indefinitely. In this work we present computations of an initial compositionally stratified fluid that is subject to a thermal gradient ΔT = T1 - T0 across the height D of a rectangular domain over a range of buoyancy numbers B and Rayleigh numbers Ra. In these computations we compare three numerical approaches to modeling the movement of two distinct, thermally driven, compositional fields; namely, a high-order Finte Element Method (FEM) that employs artifical viscosity to preserve the maximum and minimum values of the compositional field, a Discontinous Galerkin (DG) method with a Bound Preserving (BP) limiter, and a Volume-of-Fluid (VOF) interface tracking algorithm. Our computations demonstrate that the FEM approach has far too much numerical diffusion to yield meaningful results, the DGBP method yields much better resuts but with small amounts of each compositional field being (numerically) entrained within the other compositional field, while the VOF method maintains a sharp interface between the two compositions throughout the computation. In the figure we show a comparison of between the three methods for a computation made with B = 1.111 and Ra = 10,000 after the flow has reached 'steady state'. (R) the images computed with the standard FEM method (with artifical viscosity), (C) the images computed with the DGBP method (with no artifical viscosity or diffusion due to discretization errors) and (L) the images computed with the VOF algorithm.

[Pyometra and persistent hymen in an alpaca].

PubMed

Egloff, C; Gerspach, C; Rütten, M; Dettwiler, M; Reichler, I; Bleul, U

2013-01-01

A 3-year-old female alpaca was referred to the hospital because of tenesmus. Clinical examination revealed a habitual vaginal prolapse with tenesmus during urination and defecation. On vaginoscopic examination a persistent hymen was detected. Ultrasonography of the caudal abdomen showed an echogenic fluid-filled uterus. A diagnostic laparotomy led to diagnosis of pyometra. Following ovariohysterectomy, the recovery was uneventful. One and a half years later the alpaca was again admitted to the hospital because of colic. Based on the findings, a tentative prognosis was provided and the alpaca was euthanized at the request of the owner. At necropsy, a haemorrhagic infarction of a jejunal loop was found due to incarceration in a fibrous adhesion between the vaginal stump and small intestine.

A percutaneous drainage protocol for severe and moderately severe acute pancreatitis.

PubMed

Sugimoto, Motokazu; Sonntag, David P; Flint, Greggory S; Boyce, Cody J; Kirkham, John C; Harris, Tyler J; Carr, Sean M; Nelson, Brent D; Barton, Joshua G; Traverso, L William

2015-11-01

According to the revised Atlanta classification, severe and moderately severe acute pancreatitis (AP) includes patients with pancreatic and peripancreatic collections with or without organ failure. These collections suggest the presence of pancreatic juice leakage. The aim of this study was to evaluate the efficacy of a percutaneous catheter drainage (PCD) protocol designed to control leakage and decrease disease severity. Among 663 patients with clinical AP, 122 were classified as moderately severe or severe AP (all had collections). The computed tomography severity index (CTSI) score was calculated. The indication for PCD was based on progressive clinical signs and symptoms. Drain patency, position, and need for additional drainage sites were assessed using CT scans and drain studies initially every 3 days using a proactive protocol. Drain fluid was examined for amylase concentration and microbiological culture. Clinicopathological variables for patients with and without PCD were compared. Since there was no mortality, we used prolonged drainage time to measure the success of PCD. Within the group treated with PCD, variables that resulted in prolonged drainage time were analyzed. PCD was used in 47/122 (39 %) patients of which 33/47 (70 %) had necrosis. PCD cases had a median CTSI of 8 and were classified as moderately severe AP (57 %) and severe AP (43 %). Inhospital mortality was zero. Surgical necrosectomy was not required for patients with necrosis. Independent risk factors for prolonged drainage time were persistent organ failure >48 h (P = 0.001), CTSI 8-10 (P = 0.038), prolonged duration of amylase-rich fluid in drains (P < 0.001), and polymicrobial culture fluid in drains (P = 0.015). A proactive PCD protocol persistently maintaining drain patency advanced to the site of leak controlled the prolonged amylase in drainage fluid resulting in a mortality rate of zero.

The role of uplift and erosion in the persistence of saline groundwater in the shallow subsurface

NASA Astrophysics Data System (ADS)

Yager, R. M.; McCoy, K. J.; Voss, C. I.; Sanford, W. E.; Winston, R. B.

2017-04-01

In many regions of the world, the shallow (<300 m) subsurface is replenished with meteoric recharge within a few centuries or millennia, but in some regions saline groundwater persists despite abundant rainfall. Analyses of the flushing rate of shallow groundwater usually consider the permeability and recharge rate and a static landscape. The influence of landscape evolution can become important over millions of years, however. Here we present numerical simulations of fluid flow and transport in the top 1 km of a sedimentary foreland basin dominated by aquitards, where the rate of uplift and erosion (20 m Ma-1) balances that of meteoric flushing. Paleozoic age saline groundwater and brine persist at shallow depths that might otherwise have contained potable water. Similar hydrogeologic conditions, and uplift and erosion rates, likely exist in many other regions of the world, where a moving landscape has probably never been considered as an important contributor to groundwater quality.

The role of uplift and erosion in the persistence of saline groundwater in the shallow subsurface

USGS Publications Warehouse

Yager, Richard M.; McCoy, Kurt J.; Voss, Clifford I.; Sanford, Ward E.; Winston, Richard B.

2017-01-01

In many regions of the world, the shallow (<300 m) subsurface is replenished with meteoric recharge within a few centuries or millennia, but in some regions saline groundwater persists despite abundant rainfall. Analyses of the flushing rate of shallow groundwater usually consider the permeability and recharge rate and a static landscape. The influence of landscape evolution can become important over millions of years, however. Here we present numerical simulations of fluid flow and transport in the top 1 km of a sedimentary foreland basin dominated by aquitards, where the rate of uplift and erosion (20 m Ma−1) balances that of meteoric flushing. Paleozoic age saline groundwater and brine persist at shallow depths that might otherwise have contained potable water. Similar hydrogeologic conditions, and uplift and erosion rates, likely exist in many other regions of the world, where a moving landscape has probably never been considered as an important contributor to groundwater quality.

Characterization of the chemicals used in hydraulic fracturing fluids for wells located in the Marcellus Shale Play.

PubMed

Chen, Huan; Carter, Kimberly E

2017-09-15

Hydraulic fracturing, coupled with the advances in horizontal drilling, has been used for recovering oil and natural gas from shale formations and has aided in increasing the production of these energy resources. The large volumes of hydraulic fracturing fluids used in this technology contain chemical additives, which may be toxic organics or produce toxic degradation byproducts. This paper investigated the chemicals introduced into the hydraulic fracturing fluids for completed wells located in Pennsylvania and West Virginia from data provided by the well operators. The results showed a total of 5071 wells, with average water volumes of 5,383,743 ± 2,789,077 gal (mean ± standard deviation). A total of 517 chemicals was introduced into the formulated hydraulic fracturing fluids. Of the 517 chemicals listed by the operators, 96 were inorganic compounds, 358 chemicals were organic species, and the remaining 63 cannot be identified. Many toxic organics were used in the hydraulic fracturing fluids. Some of them are carcinogenic, including formaldehyde, naphthalene, and acrylamide. The degradation of alkylphenol ethoxylates would produce more toxic, persistent, and estrogenic intermediates. Acrylamide monomer as a primary degradation intermediate of polyacrylamides is carcinogenic. Most of the chemicals appearing in the hydraulic fracturing fluids can be removed when adopting the appropriate treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular analysis of bacterial diversity in kerosene-based drilling fluid from the deep ice borehole at Vostok, East Antarctica.

PubMed

Alekhina, Irina A; Marie, Dominique; Petit, Jean Robert; Lukin, Valery V; Zubkov, Vladimir M; Bulat, Sergey A

2007-02-01

Decontamination of ice cores is a critical issue in phylogenetic studies of glacial ice and subglacial lakes. At the Vostok drill site, a total of 3650 m of ice core have now been obtained from the East Antarctic ice sheet. The ice core surface is coated with a hard-to-remove film of impure drilling fluid comprising a mixture of aliphatic and aromatic hydrocarbons and foranes. In the present study we used 16S rRNA gene sequencing to analyze the bacterial content of the Vostok drilling fluid sampled from four depths in the borehole. Six phylotypes were identified in three of four samples studied. The two dominant phylotypes recovered from the deepest (3400 and 3600 m) and comparatively warm (-10 degrees C and -6 degrees C, respectively) borehole horizons were from within the genus Sphingomonas, a well-known degrader of polyaromatic hydrocarbons. The remaining phylotypes encountered in all samples proved to be human- or soil-associated bacteria and were presumed to be drilling fluid contaminants of rare occurrence. The results obtained indicate the persistence of bacteria in extremely cold, hydrocarbon-rich environments. They show the potential for contamination of ice and subglacial water samples during lake exploration, and the need to develop a microbiological database of drilling fluid findings.

Osmotic generation of 'anomalous' fluid pressures in geological environments

USGS Publications Warehouse

Neuzii, C.E.

2000-01-01

Osmotic pressures are generated by differences in chemical potential of a solution across a membrane. But whether osmosis can have a significant effect on the pressure of fluids in geological environments has been controversial, because the membrane properties of geological media are poorly understood. 'Anomalous' pressures - large departures from hydrostatic pressure that are not explicable in terms of topographic or fluid-density effects are widely found in geological settings, and are commonly considered to result from processes that alter the pore or fluid volume, which in turn implies crustal changes happening at a rate too slow to observe directly. Yet if osmosis can explain some anomalies, there is no need to invoke such dynamic geological processes in those cases. Here I report results of a nine- year in situ measurement of fluid pressures and solute concentrations in shale that are consistent with the generation of large (up to 20 MPa) osmotic-pressure anomalies which could persist for tens of millions of years. Osmotic pressures of this magnitude and duration can explain many of the pressure anomalies observed in geological settings. The require, however, small shale porosity and large contrasts in the amount of dissolved solids in the pore waters - criteria that may help to distinguish between osmotic and crystal-dynamic origins of anomalous pressures.

Failure of Working Memory Training to Enhance Cognition or Intelligence

PubMed Central

Thompson, Todd W.; Waskom, Michael L.; Garel, Keri-Lee A.; Cardenas-Iniguez, Carlos; Reynolds, Gretchen O.; Winter, Rebecca; Chang, Patricia; Pollard, Kiersten; Lala, Nupur; Alvarez, George A.; Gabrieli, John D. E.

2013-01-01

Fluid intelligence is important for successful functioning in the modern world, but much evidence suggests that fluid intelligence is largely immutable after childhood. Recently, however, researchers have reported gains in fluid intelligence after multiple sessions of adaptive working memory training in adults. The current study attempted to replicate and expand those results by administering a broad assessment of cognitive abilities and personality traits to young adults who underwent 20 sessions of an adaptive dual n-back working memory training program and comparing their post-training performance on those tests to a matched set of young adults who underwent 20 sessions of an adaptive attentional tracking program. Pre- and post-training measurements of fluid intelligence, standardized intelligence tests, speed of processing, reading skills, and other tests of working memory were assessed. Both training groups exhibited substantial and specific improvements on the trained tasks that persisted for at least 6 months post-training, but no transfer of improvement was observed to any of the non-trained measurements when compared to a third untrained group serving as a passive control. These findings fail to support the idea that adaptive working memory training in healthy young adults enhances working memory capacity in non-trained tasks, fluid intelligence, or other measures of cognitive abilities. PMID:23717453

Relationship of Specific Vaginal Bacteria and Bacterial Vaginosis Treatment Failure in Women Who Have Sex with Women: A Cohort Study

PubMed Central

Marrazzo, Jeanne M.; Thomas, Katherine K.; Fiedler, Tina L.; Ringwood, Kathleen; Fredricks, David N.

2008-01-01

Background Bacterial vaginosis frequently persists after treatment. The role of newly defined bacterial vaginosis-associated bacteria (BVAB), with specificity ≥97% for this condition, has not been assessed. Objective Define risks for bacterial vaginosis persistence, including pre-treatment detection of specific vaginal bacteria, among women reporting sex with other women. Design Observational cohort study. Setting University-based research clinic. Patients 335 women 16–29 years-old reporting sex with ≥1 woman in the prior year recruited through advertisements and provider referral. Intervention Bacterial vaginosis was treated with intravaginal metronidazole gel (0.75%), 37.5 mg nightly for five nights. Measurements Species-specific 16S rDNA polymerase chain reaction (PCR) assays targeting 17 bacteria were applied to vaginal fluid obtained at baseline. Test of cure by clinical criteria and Gram stain analysis and repeat PCR assays of vaginal fluid were performed one month post-treatment, and interim behaviors assessed using computer-assisted self-interview. Results Of 335 women, 24% of whom also reported sex with men within 3 months before enrollment, 131 (39%) had bacterial vaginosis. In 120 (92%) with follow-up, incidence of persistent bacterial vaginosis was 26%, and significantly higher in women with baseline detection of Clostridia-like bacteria designated BVAB1 (risk ratio (95% C.I.) 2.0 (1.1–4.0), BVAB2 (risk ratio (95% C.I.) 8.7 (2.5-∞), or BVAB3 (risk ratio (95% C.I.) 3.1 (1.7–5.8)), or of Peptoniphilus lacrimalis (risk ratio (95% C.I.) 3.5 (1.6–15.5)) or Megasphaera phylotype 2 (risk ratio (95% C.I.) 3.4 (1.4–5.5)), and lower with treatment adherence (risk ratio (95% C.I.) 0.4 (0.2–0.9)). Detection of these bacteria at test-of-cure was associated with persistence, while post-treatment sexual activity was not. Limitations Findings may not be generalizable to women who have sex only with men, or to women whose bacterial vaginosis is treated with oral antibiotic. The study may be too small and involve too selected a population to draw definitive conclusions about associations of persistent infection with post-treatment sexual behaviors. Conclusions Persistent bacterial vaginosis is associated with several Clostridiales order bacteria and Peptoniphilus lacrimalis, suggesting that vaginal microbiology at diagnosis may define risk for antibiotic failure. PMID:18591634

[DIAGNOSTIC VALUE OF COMBINED USE OF COMBINED METHOD OF ENZYME IMMUNOASSAY AND POLYMERASE CHAIN REACTION TO DETECT OF INTRAUTERINE FETAL INFECTION BY PARVOVIRUS B19].

PubMed

Bondarenko, N P; Lakatosh, V P; Lakatosh, P V; Malanchuk, O B; Poladich, I V

2015-01-01

The combined method of diagnosis parvovirus infection during pregnancy by maternal serum enzyme immunoassay and deoxyribonucleic acid isolation parvovirus B19 polymerase chain reaction in amnniotic fluid and fetal cord blood newborns, can diagnose vertical transmission and anticipate a negative effect on the fetus parvovirus. Lack of maternal IgM antibodies in serum due to parvovirus seroconversion during pregnancy does not exclude the persistence of the virus in the fetus. To analyze the diagnostic value of the method for determining the LHP parvovirus B19 DNA in the amniotic fluid, umbilical cord blood of newborns to determine vertical transmission of parvovirus infection when infected mothers B19 during pregnancy.

A Chlorine-Centric Perspective on Fluid-Mediated Processes at Convergent Plate Boundaries

NASA Astrophysics Data System (ADS)

Selverstone, J.

2014-12-01

The release and migration of metamorphic fluids from subducting slabs into overlying mantle is widely recognized as a major mechanism in producing arc geochemical signatures and returning fluid-mobile elements to earth's crust and surface environments. Although the magnitudes of many geochemical fluxes are well constrained, the processes whereby mass transfer occurs in different portions of the subduction system are less well known. Chlorine stable isotopes provide a new perspective on some of these processes: Cl is hydrophilic, but decarbonation reactions favor Cl retention in minerals. Cl also shows less isotopic fractionation than other fluid-sensitive systems and may thus preserve evidence of specific fluid sources and/or fluid mixing events. Detailed studies of sedimentary sequences show that individual beds are isotopically homogeneous but large heterogeneities in δ37Cl exist across beds on a cm to m scale and vary as a function of depositional environment. Compositionally correlative medium-, high-, and ultrahigh-pressure metamorphic sequences in the Alps record decreases of 30-50% in Cl contents in the earliest stages of metamorphism, but little change thereafter. No statistically significant change in isotopic composition occurs during prograde metamorphism of individual horizons, and the same large degree of isotopic heterogeneity (up to 6‰) persists throughout the prograde devolatilization history of the rocks. Likewise, analysis of HP/UHP serpentinites and altered oceanic crust show that heterogeneous protolith compositions are preserved during transport to sub-arc depths, despite large-scale devolatilization. However, upward transport of rocks within the subduction channel results in highly localized interaction with isotopically distinct, Cl-bearing fluid packets. Overlying forearc wedge rocks also record heterogeneous and channelized interaction with distinct fluid components with different δ37Cl. Within-layer fluid compartmentalization during continuous devolatilization reactions must thus be reconciled with discontinuous, cross-layer fluid percolation out of the slab and into the wedge. The resulting implications of the chlorine data for recent mechanical models of slab-to-wedge fluid transport will be discussed.

Trypanosoma cruzi persistence in the native heart is associated with high-grade myocarditis, but not with Chagas' disease reactivation after heart transplantation.

PubMed

Benvenuti, Luiz A; Roggério, Alessandra; Nishiya, Anna S; Campos, Silvia V; Fiorelli, Alfredo I; Levi, José E

2014-07-01

Chagas' disease reactivation (CDR) after heart transplantation (HTx) is characterized by relapse of the infectious disease, with direct detection of Trypanosoma cruzi parasites in blood, cerebrospinal fluid, or tissues. We investigated whether a detailed pathologic examination of the explanted heart at HTx with evaluation of myocarditis and parasitic persistence or load in the myocardium could be useful to identify patients at high risk of CDR. The native hearts of 18 chagasic patients who presented CDR after HTx (CDR+ group) were compared with the native hearts of 16 chagasic patients who never presented CDR in a follow-up of at least 18 months after HTx (CDR- group). The intensity of myocarditis was evaluated semiquantitatively. Parasite persistence/load in the myocardium was investigated through immunohistochemistry for T cruzi antigens and by qualitative and quantitative real-time PCR for T cruzi DNA. The rate of high-grade myocarditis, parasite persistence, and the median of parasitic load and parasitic load/10(6) cells in the CDR+ group were 83.3%, 77.8%, 8.43 × 10(-3), and 9.890, respectively, whereas in the CDR- group the values were 87.5%, 50%, 7.49×10(-3), and 17.800. There was no statistical difference between the groups. High-grade myocarditis was present in all 22 samples (100%) with parasite persistence and in 7 of 12 samples (58.3%) with no parasite persistence (p = 0.003). Although associated with high-grade myocarditis, T cruzi parasite persistence in the myocardium of the native heart is not associated with the occurrence of CDR after HTx. Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

The Effects of Double Diffusion and Background Turbulence on the Persistence of Submarine Wakes

DTIC Science & Technology

2016-03-01

acoustic detection of submerged objects. 14. SUBJECT TERMS fluid dynamics, submarine, wakes, turbulence 15. NUMBER OF PAGES 41 16. PRICE CODE...microstructure-based observations of stratified wakes offer a viable method for the non- acoustic detection of submerged objects. vi THIS PAGE...25 viii THIS PAGE INTENTIONALLY LEFT BLANK ix LIST OF FIGURES Figure 1. Velocity Profiles of Towed and Jet- Propelled Body

Congenital Hydrocephalus.

PubMed

Estey, Chelsie M

2016-03-01

There are several types of hydrocephalus, which are characterized based on the location of the cerebrospinal fluid (CSF) accumulation. Physical features of animals with congenital hydrocephalus may include a dome-shaped skull, persistent fontanelle, and bilateral ventrolateral strabismus. Medical therapy involves decreasing the production of CSF. The most common surgical treatment is placement of a ventriculoperitoneal shunt. Postoperative complications may include infection, blockage, drainage abnormalities, and mechanical failure. Copyright © 2016 Elsevier Inc. All rights reserved.

Emergent scar lines in chaotic advection of passive directors

NASA Astrophysics Data System (ADS)

Hejazi, Bardia; Mehlig, Bernhard; Voth, Greg A.

2017-12-01

We examine the spatial field of orientations of slender fibers that are advected by a two-dimensional fluid flow. The orientation field of these passive directors are important in a wide range of industrial and geophysical flows. We introduce emergent scar lines as the dominant coherent structures in the orientation field of passive directors in chaotic flows. Previous work has identified the existence of scar lines where the orientation rotates by π over short distances, but the lines that were identified disappeared as time progressed. As a result, earlier work focused on topological singularities in the orientation field, which we find to play a negligible role at long times. We use the standard map as a simple time-periodic two-dimensional flow that produces Lagrangian chaos. This class of flows produces persistent patterns in passive scalar advection and we find that a different kind of persistent pattern develops in the passive director orientation field. We identify the mechanism by which emergent scar lines grow to dominate these patterns at long times in complex flows. Emergent scar lines form where the recent stretching of the fluid element is perpendicular to earlier stretching. Thus these scar lines can be labeled by their age, defined as the time since their stretching reached a maximum.

Drain Tube-Induced Jejunal Penetration Masquerading as Bile Leak following Whipple's Operation.

PubMed

Bae, Sang Ho; Lee, Tae Hoon; Lee, Sae Hwan; Lee, Suck-Ho; Park, Sang-Heum; Kim, Sun-Joo; Kim, Chang Ho

2011-05-01

A 70-year-old man had undergone pancreaticoduodenectomy due to a distal common bile duct malignancy. After the operation, serous fluid discharge decreased from two drain tubes in the retroperitoneum. Over four weeks, the appearance of the serous fluid changed to a greenish bile color and the patient persistently drained over 300 ml/day. Viewed as bile leak at the choledochojejunostomy, treatment called for endoscopic diagnosis and therapy. Cap-fitted forward-viewing endoscopy demonstrated that the distal tip of a pancreatic drain catheter inserted at the pancreaticojejunostomy site had penetrated the opposite jejunum wall. One of the drain tubes primarily placed in the retroperitoneum had also penetrated the jejunum wall, with the distal tip positioned near the choledochojejunostomy site. No leak of contrast appeared beyond the jejunum or anastomosis site. Following repositioning of a penetrating catheter of the pancreaticojejunostomy, four days later, the patient underwent removal of two drain tubes without additional complications. In conclusion, the distal tip of the catheter, placed to drain pancreatic juice, penetrated the jejunum wall and may have caused localized perijejunal inflammation. The other drain tube, placed in the retroperitoneal space, might then have penetrated the inflamed wall of the jejunum, allowing persistent bile drainage via the drain tube. The results masqueraded as bile leakage following pancreaticoduodenectomy.

Description and detection of burst events in turbulent flows

NASA Astrophysics Data System (ADS)

Schmid, P. J.; García-Gutierrez, A.; Jiménez, J.

2018-04-01

A mathematical and computational framework is developed for the detection and identification of coherent structures in turbulent wall-bounded shear flows. In a first step, this data-based technique will use an embedding methodology to formulate the fluid motion as a phase-space trajectory, from which state-transition probabilities can be computed. Within this formalism, a second step then applies repeated clustering and graph-community techniques to determine a hierarchy of coherent structures ranked by their persistencies. This latter information will be used to detect highly transitory states that act as precursors to violent and intermittent events in turbulent fluid motion (e.g., bursts). Used as an analysis tool, this technique allows the objective identification of intermittent (but important) events in turbulent fluid motion; however, it also lays the foundation for advanced control strategies for their manipulation. The techniques are applied to low-dimensional model equations for turbulent transport, such as the self-sustaining process (SSP), for varying levels of complexity.

Fluid front morphologies in gap-modulated Hele-Shaw cells

NASA Astrophysics Data System (ADS)

Díaz-Piola, Lautaro; Planet, Ramon; Campàs, Otger; Casademunt, Jaume; Ortín, Jordi

2017-09-01

We consider the displacement of an inviscid fluid (air) by a viscous fluid (oil) in a narrow channel with gap-thickness modulations. The interfacial dynamics of this problem is strongly nonlocal and exhibits competing effects from capillarity and permeability. We derive analytical predictions of steady-state front morphologies, which are exact at linear level in the case of a persistent modulation in the direction of front advancement. The theoretical predictions are in good agreement with experimental measurements of steady-state front morphologies obtained in a Hele-Shaw cell with modulations of the channel depth, consisting on three parallel tracks of reduced depth, for small gap modulations. The relative average distance between theoretical and experimental fronts in the region around the central track is smaller than about 4 % , provided that the height of the tracks is less than 13 % of the total channel depth and the local distortion of the front height h is small enough (|∇ h |<0.8 ) for the linear approximation to hold.

Elimination and Concentration Correlations between Edible Tissues and Biological Fluids and Hair of Ractopamine in Pigs and Goats Fed with Ractopamine-Medicated Feed.

PubMed

Huang, Lingli; Shi, Jingfei; Pan, Yuanhu; Wang, Liye; Chen, Dongmei; Xie, Shuyu; Liu, Zhenli; Yuan, Zonghui

2016-03-09

Ractopamine (RAC), a β-adrenergic leanness-enhancing agent, endangers the food safety of animal products because of overdosing and illegal use in food animals. Excretion and residue depletion of RAC in pigs and goats were investigated to determine a representative biological fluid or surface tissue for preslaughter monitoring. After a single oral gavage of RAC, 64-67% of the dose was excreted from the urine of pigs and goats within 12-24 h. RAC persisted the longest in the hair of pigs and goats but depleted rapidly in the plasma, muscle, and fat. Urine and hair were excellent for predicting RAC residues in edible tissues of pigs, whereas plasma and urine were satisfactory body fluids for the prediction of RAC concentrations in edible tissues of goats. These data provided a simple and economical preslaughter living monitoring method for the illegal use and violative residue of RAC in food animals.

Ecological and Toxicological Characteristics of Metalworking Fluids Used in Finishing Processing in Russian Federation

NASA Astrophysics Data System (ADS)

Grigoriev, S. N.; Bobrovskij, N. M.; Melnikov, P. A.; Bobrovskij, I. N.; Levitskih, O. O.

2017-05-01

Nowadays, metalworking fluids (MWF) in the design of technological processes in most cases are considered as mandatory persistant components despite the constant improvement of the technology of machining, tools and equipment. Three main functions of MWF: cooling, lubrication, waste chips removal - seems to be the essential condition for stable process. In most cases, cooling reduces wear of tool and improves the quality of the processed surface. The cooling characteristics of the MWF affect not only the heat capacity and thermal conductivity, but metal surfaces wettability and vaporization. If processing speed and temperature of the fluid are high then it may not be in direct contact with the surface of the tool due to low wettability or vapor blankets. Improvement of machining process with applying the MWF is accompanied with negative factors. Due to the high temperatures in the treatment area it is exposed to MWF vaporization. This article presents estimation of the applicable in Russian Federation MWF: fire risk, toxicological and environmental hazards.

Characterization of renal response to prolonged immersion in normal man

NASA Technical Reports Server (NTRS)

Epstein, M.; Denunzio, A. G.; Ramachandran, M.

1980-01-01

?jDuring the initial phase of space flight, there is a translocation of fluid from the lower parts of the body to the central vascular compartment with a resultant natriuresis, diuresis, and weight loss. Because water immersion is regarded as an appropriate model for studying the redistribution of fluid that occurs in weightlessness, an immersion study of relatively prolonged duration was carried out in order to characterize the temporal profile of the renal adaptation to central hypervolemia. Twelve normal male subjects underwent an immersion study of 8-h duration in the sodium-replete state. Immersion resulted in marked natriuresis and diuresis which were sustained throughout the immersion period. The failure of that natriuresis and diuresis of immersion to abate or cease despite marked extracellular fluid volume contraction as evidenced by a mean weight loss of -2.2 + or - 0.3 kg suggests that central blood volume was not restored to normal and that some degree of central hypervolemia probably persisted.

On the Rigid-Lid Approximation for Two Shallow Layers of Immiscible Fluids with Small Density Contrast

NASA Astrophysics Data System (ADS)

Duchêne, Vincent

2014-08-01

The rigid-lid approximation is a commonly used simplification in the study of density-stratified fluids in oceanography. Roughly speaking, one assumes that the displacements of the surface are negligible compared with interface displacements. In this paper, we offer a rigorous justification of this approximation in the case of two shallow layers of immiscible fluids with constant and quasi-equal mass density. More precisely, we control the difference between the solutions of the Cauchy problem predicted by the shallow-water (Saint-Venant) system in the rigid-lid and free-surface configuration. We show that in the limit of a small density contrast, the flow may be accurately described as the superposition of a baroclinic (or slow) mode, which is well predicted by the rigid-lid approximation, and a barotropic (or fast) mode, whose initial smallness persists for large time. We also describe explicitly the first-order behavior of the deformation of the surface and discuss the case of a nonsmall initial barotropic mode.

Permeability and seismic velocity anisotropy across a ductile-brittle fault zone in crystalline rock

NASA Astrophysics Data System (ADS)

Wenning, Quinn C.; Madonna, Claudio; de Haller, Antoine; Burg, Jean-Pierre

2018-05-01

This study characterizes the elastic and fluid flow properties systematically across a ductile-brittle fault zone in crystalline rock at the Grimsel Test Site underground research laboratory. Anisotropic seismic velocities and permeability measured every 0.1 m in the 0.7 m across the transition zone from the host Grimsel granodiorite to the mylonitic core show that foliation-parallel P- and S-wave velocities systematically increase from the host rock towards the mylonitic core, while permeability is reduced nearest to the mylonitic core. The results suggest that although brittle deformation has persisted in the recent evolution, antecedent ductile fabric continues to control the matrix elastic and fluid flow properties outside the mylonitic core. The juxtaposition of the ductile strain zone next to the brittle zone, which is bounded inside the two mylonitic cores, causes a significant elastic, mechanical, and fluid flow heterogeneity, which has important implications for crustal deformation and fluid flow and for the exploitation and use of geothermal energy and geologic waste storage. The results illustrate how physical characteristics of faults in crystalline rocks change in fault zones during the ductile to brittle transitions.

Atomization and dense-fluid breakup regimes in liquid rocket engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oefelein, Joseph; Dahms, Rainer Norbert Uwe

Until recently, modern theory has lacked a fundamentally based model to predict the operating pressures where classical sprays transition to dense-fluid mixing with diminished surface tension. In this paper, such a model is presented to quantify this transition for liquid-oxygen–hydrogen and n-decane–gaseous-oxygen injection processes. The analysis reveals that respective molecular interfaces break down not necessarily because of vanishing surface tension forces but instead because of the combination of broadened interfaces and a reduction in mean free molecular path. When this occurs, the interfacial structure itself enters the continuum regime, where transport processes rather than intermolecular forces dominate. Using this model,more » regime diagrams for the respective systems are constructed that show the range of operating pressures and temperatures where this transition occurs. The analysis also reveals the conditions where classical spray dynamics persists even at high supercritical pressures. As a result, it demonstrates that, depending on the composition and temperature of the injected fluids, the injection process can exhibit either classical spray atomization, dense-fluid diffusion-dominated mixing, or supercritical mixing phenomena at chamber pressures encountered in state-of-the-art liquid rocket engines.« less

Atomization and dense-fluid breakup regimes in liquid rocket engines

DOE PAGES

Oefelein, Joseph; Dahms, Rainer Norbert Uwe

2015-04-20

Until recently, modern theory has lacked a fundamentally based model to predict the operating pressures where classical sprays transition to dense-fluid mixing with diminished surface tension. In this paper, such a model is presented to quantify this transition for liquid-oxygen–hydrogen and n-decane–gaseous-oxygen injection processes. The analysis reveals that respective molecular interfaces break down not necessarily because of vanishing surface tension forces but instead because of the combination of broadened interfaces and a reduction in mean free molecular path. When this occurs, the interfacial structure itself enters the continuum regime, where transport processes rather than intermolecular forces dominate. Using this model,more » regime diagrams for the respective systems are constructed that show the range of operating pressures and temperatures where this transition occurs. The analysis also reveals the conditions where classical spray dynamics persists even at high supercritical pressures. As a result, it demonstrates that, depending on the composition and temperature of the injected fluids, the injection process can exhibit either classical spray atomization, dense-fluid diffusion-dominated mixing, or supercritical mixing phenomena at chamber pressures encountered in state-of-the-art liquid rocket engines.« less

Prediction of fingering in porous media

NASA Astrophysics Data System (ADS)

Wang, Zhi; Feyen, Jan; Elrick, David E.

1998-09-01

Immiscible displacement, involving two fluids in a porous medium, can be unstable and fingered under certain conditions. In this paper, the original linear instability criterion of Chuoke et al. [1959] is generalized, considering wettability of two immiscible fluids to the porous medium. This is then used to predict 24 specific flow and porous medium conditions for the onset of wetting front instability in the subsurface. Wetting front instability is shown to be a function of the driving fluid wettability to the medium, differences in density and viscosity of the fluids, the magnitude of the interfacial tension, and the direction of flow with respect to gravity. Scenarios of water and nonaqueous-phase liquid infiltration into the vadose zone are examined to predict preferential flow and contamination of groundwater. The mechanisms of finger formation, propagation, and persistence in the vadose zone are reviewed, and the existing equations for calculating the size, the number and velocity of fingers are simplified for field applications. The analyses indicate that fingers initiate and propagate according to spatial and temporal distribution of the dynamic breakthrough (water- or air-entry) pressures in the porous medium. The predicted finger size and velocity are in close agreement with the experimental results.

Subarachnoidal-pleural fistula (SAPF) as an unusual cause of persistent pleural effusion. Beta-trace protein as a marker for SAPF. Case report and review of the literature.

PubMed

Deseyne, S; Vanhouteghem, K; Hallaert, G; Delanghe, J; Malfait, T

2015-02-01

We describe a case of a 56-year-old woman who developed a recurrent pleural effusion after a thoracoscopic resection of an anterior bulging thoracic disc hernia (level D9-D10). Despite several evacuating pleural punctions, dyspnea reoccurred due to recurrent pleural effusion, the same side as the disc resection. Because of increasing headache after each punction, a subarachnoidal pleural fistula (SAPF) was suspected. Although magnetic resonance imaging (MRI) showed features suggestive of SAPF, there was not enough evidence to justify a new thorascopy. Cerebrospinal fluid (CSF) leakage into the thoracic and abdominal cavity has been described as a result of trauma or surgery. Detection of beta-trace protein (BTP, a brain-specific protein) has been described to detect CSF fistulae causing rhino- and otoliquorrhea. Similarly, BTP determination could be used to identify the presence of CSF at other anatomical sites such as the thoracic cavity. Therefore, we decided to determine the concentration of BTP in the pleural effusion of this patient. BTP was assayed using immunonephelometry. The patient's BTP pleural fluid concentration was 14·0 mg/l, which was a 25-fold increase compared with the BTP serum concentration. After insertion of a subarachnoidal lumbal catheter, a video-assisted thorascopy was performed. Leakage of liquor through the parietal pleura into the thoracic cavity was observed. The SAPF was closed using a durasis patch and DuraSeal®. Postoperatively, there was no reoccurrence of pleural fluid. SAPF has to be included to the differential diagnosis of patients with persistent pleural effusion after spinal surgery. This case illustrates the importance of BTP in diagnosing SAPF, especially in cases where major therapeutic consequences may need to be drawn.

Creatinine concentrations of accumulated intrauterine fluid to confirm the clinical diagnosis of urometra in mares.

PubMed

Schnobrich, M R; Gordon, D L; Scoggin, C F; Bradecamp, E A; Canisso, I F

2017-03-25

Urine pooling, as a persistent condition, is a cause of infertility in mares due to endometrial inflammation and sperm toxicity. Identification of urometra can be challenging in mares presenting with the condition intermittently, or when urine flows into the uterus but is undetectable in the vagina. Currently, there are no reported objective methods to confirm the clinical diagnosis of urine contamination in intrauterine-fluid accumulations. Since creatinine is present in high concentrations in urine and does not diffuse across cell membranes, creatinine concentration should be increased in mares with urometra, but negligible in normal and mares with intrauterine fluid accumulation (non-urometra cases). To test this hypothesis, creatinine concentrations of intrauterine fluid were measured in mares with a clinical diagnosis of urine accumulation (n=9) or intrauterine fluid containing no urine (n=10). Results showed that creatinine concentrations (mg/dl) were significantly higher in mares that had a clinical diagnosis of urometra (42.8±12.6, range 4.1-109.2) compared with those that did not (0.38±0.1, range 0-0.9). Also, two mares after urethral extension surgery demonstrated a remarkable reduction in creatinine concentrations. This study highlights an undocumented approach to confirm a clinical diagnosis of urometra in mares; the authors anticipate that testing for creatinine in the uterine fluid of mares may become a standard tool for identifying urometra in mares and confirming the success of urogenital surgeries. British Veterinary Association.

The fluid physics of signal perception by mate-tracking copepods.

PubMed Central

Yen, J; Weissburg, M J; Doall, M H

1998-01-01

Within laboratory-induced swarms of the marine copepod Temora longicornis, the male exhibits chemically mediated trail-following behaviour, concluding with fluid mechanical provocation of the mate-capture response. The location and structure of the invisible trail were determined by examining the specific behaviour of the female copepods creating the signal, the response of the male to her signal, and the fluid physics of signal persistence. Using the distance of the mate-tracking male from the ageing trail of the female, we estimated that the molecular diffusion coefficient of the putative pheromonal stimulant was 2.7 x 10(-5) cm2 s-1, or 1000 times slower than the diffusion of momentum. Estimates of signal strength levels, using calculations of diffusive properties of odour trails and attenuation rates of fluid mechanical signals, were compared to the physiological and behavioural threshold detection levels. Males find trails because of strong across-plume chemical gradients; males sometimes go the wrong way because of weak along-plume gradients; males lose the trail when the female hops because of signal dilution; and mate-capture behaviour is elicited by suprathreshold flow signals. The male is stimulated by the female odour to accelerate along the trail to catch up with her, and the boundary layer separating the signal from the chemosensitive receptors along the copepod antennule thins. Diffusion times, and hence reaction times, shorten and behavioural orientation responses can proceed more quickly. While 'perceptive' distance to the odour signal in the trail or the fluid mechanical signal from the female remains within 1-2 body lengths (< 5 mm), the 'reactive' distance between males and females was an order of magnitude larger. Therefore, when nearest-neighbour distances are 5 cm or less, as in swarms of 10(4) copepods m-3, mating events are facilitated. The strong similarity in the structure of mating trails and vortex tubes (isotropic, millimetre-centimetre scale, 10:1 aspect ratio, 10s persistence), indicates that these trails are constrained by the same physical forces that influence water motion in a low Reynolds number fluid regime, where viscosity limits forces to the molecular scale. The exploratory reaches of mating trails appear inscribed within Kolmogorov eddies and may represent a measure of eddy size. Biologically formed mating trails, however, are distinct in their flow velocity and chemical composition from common small-scale turbulent features; and mechanoreceptive and chemoreceptive copepods use their senses to discriminate these differences. Zooplankton are not aimless wanderers in a featureless environment. Their ambit is replete with clues that guide them in their efforts for survival in the ocean. PMID:9652126

Associates of an elevated natriuretic peptide level in stable heart failure patients: implications for targeted management.

PubMed

Jan, Aftab; Dawkins, Ian; Murphy, Niamh; Collier, Patrick; Baugh, John; Ledwidge, Mark; McDonald, Kenneth; Watson, Chris J

2013-01-01

Persistently elevated natriuretic peptide (NP) levels in heart failure (HF) patients are associated with impaired prognosis. Recent work suggests that NP-guided therapy can improve outcome, but the mechanisms behind an elevated BNP remain unclear. Among the potential stimuli for NP in clinically stable patients are persistent occult fluid overload, wall stress, inflammation, fibrosis, and ischemia. The purpose of this study was to identify associates of B-type natriuretic peptide (BNP) in a stable HF population. In a prospective observational study of 179 stable HF patients, the association between BNP and markers of collagen metabolism, inflammation, and Doppler-echocardiographic parameters including left ventricular ejection fraction (LVEF), left atrial volume index (LAVI), and E/e prime (E/e') was measured. Univariable associates of elevated BNP were age, LVEF, LAVI, E/e', creatinine, and markers of collagen turnover. In a multiple linear regression model, age, creatinine, and LVEF remained significant associates of BNP. E/e' and markers of collagen turnover had a persistent impact on BNP independent of these covariates. Multiple variables are associated with persistently elevated BNP levels in stable HF patients. Clarification of the relative importance of NP stimuli may help refine NP-guided therapy, potentially improving outcome for this at-risk population.

Definition of "persistent vomiting" in current medical literature: A systematic review.

PubMed

Morra, Mostafa Ebraheem; Elshafay, Abdelrahman; Kansakar, Aswin Ratna; Mehyar, Ghaleb Muhammad; Dang, Nguyen Phan Hoang; Mattar, Omar Mohamed; Iqtadar, Somia; Mostafa, Mostafa Reda; Hai, Vu Ngoc; Vu, Tran Le-Huy; Ghazy, Ahmed Abdelmotaleb; Kaboub, Fatima; Huy, Nguyen Tien; Hirayama, Kenji

2017-11-01

Persistent vomiting is mentioned as a symptom of a large variety of systemic disorders. It is commonly used interchangeably with chronic, recurrent, or intractable vomiting and widely used as a warning sign of severe illness in dengue infection. However, it has been poorly defined in the medical literature. Therefore, we aimed to systematically review a definition of persistent vomiting in the medical literature. A systematic search was done through; PubMed, Google Scholar, Web of Science, Scopus, VHL, WHO-GHL, Grey Literature Report, POPLINE, and SIGLE for the last 10 years. Consensus on the definition was considered to be reached if at least 50% of studies described the same definition using the Delphi consensus technique. Of 2362 abstracts reviewed, 15 studies were selected based on the inclusion criteria. Three studies used the same definition. Another 2 studies defined it as vomiting of all foods and fluid in 24 hours. Three studies defined persistent vomiting in the units of days or weeks. Four studies used the number of episodes: ≥2 episodes 15 minutes apart, >3 episodes in 12 hours, and >3 episodes within 24 hours. No consensus for the definition was found among authors. This is a point of concern that needs to be addressed by further studies.

Vascular Endothelial Growth Factor (VEGF) mRNA Isoforms are Altered in Bovine Granulosa Cells (GC) by Circulating Progestin Concentrations (P4) and May Indicate Follicle Status and Oocyte Competence

USDA-ARS?s Scientific Manuscript database

Previously, Melengestrol Acetate (MGA) fed for 14 d (0.5mg/cow/d; < 1 ng/ml P4) resulted in persistent follicles with increased size, decreased number of GC/follicular fluid (FF) volume, and less fertile oocytes. An experiment was conducted to determine effects of circulating P4 on amount of mRNA fo...

An Example of Genetically Distinct HIV Type 1 Variants in Cerebrospinal Fluid and Plasma During Suppressive Therapy

PubMed Central

Dahl, Viktor; Gisslen, Magnus; Hagberg, Lars; Peterson, Julia; Shao, Wei; Spudich, Serena; Price, Richard W.; Palmer, Sarah

2014-01-01

We sequenced the genome of human immunodeficiency virus type 1 (HIV-1) recovered from 70 cerebrospinal fluid (CSF) specimens and 29 plasma samples and corresponding samples obtained before treatment initiation from 17 subjects receiving suppressive therapy. More CSF sequences than plasma sequences were hypermutants. We determined CSF sequences and plasma sequences in specimens obtained from 2 subjects after treatment initiation. In one subject, we found genetically distinct CSF and plasma sequences, indicating that they came from HIV-1 from 2 different compartments, one potentially the central nervous system, during suppressive therapy. In addition, there was little evidence of viral evolution in the CSF during therapy, suggesting that continuous virus replication is not the major cause of viral persistence in the central nervous system. PMID:24338353

An example of genetically distinct HIV type 1 variants in cerebrospinal fluid and plasma during suppressive therapy.

PubMed

Dahl, Viktor; Gisslen, Magnus; Hagberg, Lars; Peterson, Julia; Shao, Wei; Spudich, Serena; Price, Richard W; Palmer, Sarah

2014-05-15

We sequenced the genome of human immunodeficiency virus type 1 (HIV-1) recovered from 70 cerebrospinal fluid (CSF) specimens and 29 plasma samples and corresponding samples obtained before treatment initiation from 17 subjects receiving suppressive therapy. More CSF sequences than plasma sequences were hypermutants. We determined CSF sequences and plasma sequences in specimens obtained from 2 subjects after treatment initiation. In one subject, we found genetically distinct CSF and plasma sequences, indicating that they came from HIV-1 from 2 different compartments, one potentially the central nervous system, during suppressive therapy. In addition, there was little evidence of viral evolution in the CSF during therapy, suggesting that continuous virus replication is not the major cause of viral persistence in the central nervous system.

Intra-articular corticosteroid preparations: different characteristics and their effect during inflammation induced by monosodium urate crystals in the rat subcutaneous air pouch.

PubMed

Rull, M; Clayburne, G; Sieck, M; Schumacher, H R

2003-09-01

To examine the effects of three commonly used intra-articular depot corticosteroid preparations tested in a rat air pouch model and their effect against monosodium urate (MSU) crystal-induced inflammation. Rheumatologists use intra-articular corticosteroid preparations to relieve pain and inflammation of acute monoarthritis without really knowing their effects on the synovial fluid and membrane or the differences between distinct preparations. This work compares the effect of three commonly used corticosteroid preparations in vivo, showing that they behave differently. A subcutaneous air pouch was formed in male Sprague-Dawley rats. A first group of 6-day-old air pouches were injected with 10 ml of 6 mg/ml normal saline solution, 6 mg/ml betamethasone containing both depot betamethasone acetate and soluble betamethasone phosphate (Celestone) in 9 ml of normal saline solution, 20 mg/ml of prednisolone tebutate (Hydeltra) in 9 ml of normal saline solution or 20 mg/ml of triamcinolone hexacetonide (Aristospan) in 9 ml of normal saline solution. A second group (group 2) of air pouches were injected with 15 mg of synthetic MSU crystals and 24 h later they were reinjected with 1 ml of the same three corticosteroid suspensions. For each condition four rats were killed at 6, 24, 48 h and 7 days. Pouch fluid and tissue were analysed. In the first 6 h after normal saline solution or corticosteroid injection into the air pouch there were mildly increased leucocyte counts in the air pouch fluid. Betamethasone-injected pouches showed no cells in the fluid after 6 h and no crystals after 24 h, triamcinolone-injected pouches still showed rare cells at 7 days. Both triamcinolone and prednisolone crystals persisted in higher numbers and lasted longer in the fluid than did betamethasone (P<0.05). In group 2 MSU crystal phagocytosis in the fluid was decreased in the betamethasone- (P<0.01), prednisolone- (P<0.003) and triamcinolone- (P<0.006) injected pouches when compared with the MSU crystal-injected pouches alone. Pouches injected with MSU crystals alone showed the most intense tissue inflammation at all times. After MSU, betamethasone-injected pouches had a rapid but mild decrease in the number of lining cells and inflammation. In contrast, triamcinolone- and prednisolone-injected pouches showed a very thin tissue with few or no vessels and almost no inflammation at 7 days. The pouches injected with MSU crystals and any of the corticoid preparations had three times more tophus-like structures and persistent crystals identified than the ones injected with MSU crystals alone. Each of the corticosteroid preparations by themselves produced very mild transient inflammation. The betamethasone preparation with a soluble steroid component had a quicker but milder anti-inflammatory effect on MSU crystal-induced inflammation. In contrast to the doses used, prednisolone tebutate and triamcinolone hexacetonide preparations dramatically suppressed urate crystal-induced inflammation at 7 days, but both produced atrophy and necrosis of the membrane, yielding a very thin membrane with almost no vessels. When used for MSU crystal-induced inflammation these corticosteroid preparations suppressed some aspects of inflammation but may actually promote the persistence of MSU crystals and the formation of tophi.

Residual cannabis levels in blood, urine and oral fluid following heavy cannabis use.

PubMed

Odell, Morris S; Frei, Matthew Y; Gerostamoulos, Dimitri; Chu, Mark; Lubman, Dan I

2015-04-01

An understanding of tetrahydrocannabinol (THC) kinetics and residual levels after cannabis use is essential in interpreting toxicology tests in body fluids from live subjects, particularly when used in forensic settings for drug abuse, traffic and interpersonal violence cases. However the current literature is largely based on laboratory studies using controlled cannabis dosages in experienced users, with limited research investigating the kinetics of residual THC concentrations in regular high dose cannabis users. Twenty-one dependent cannabis users were recruited at admission to two residential detoxification units in Melbourne, Australia. After being provided with information about, and consenting to, the study, subjects volunteered to provide once-daily blood, urine and oral fluid (saliva) samples for seven consecutive days following admission, involving cessation and abstinence from all cannabis use. Blood and oral fluid specimens were analysed for THC and urine specimens for the metabolite THC-COOH. In some subjects THC was detectable in blood for at least 7 days and oral fluid specimens were positive for THC up to 78 h after admission to the unit. Urinary THC-COOH concentrations exceeded 1000 ng/mL for some subjects 129 h after last use. The presented blood THC levels are higher and persist longer in some individuals than previously described, our understanding and interpretation of THC levels in long term heavy cannabis users may need to be reconsidered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

INTRAVITREAL DEXAMETHASONE IMPLANT AS ADJUVANT TREATMENT FOR BEVACIZUMAB- AND RANIBIZUMAB-RESISTANT NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: A Prospective Pilot Study.

PubMed

Barikian, Anita; Salti, Haytham; Safar, Ammar; Mahfoud, Ziyad R; Bashshur, Ziad F

2017-07-01

To study the benefit of intravitreal dexamethasone implant in the management of neovascular age-related macular degeneration resistant to bevacizumab and ranibizumab. Patients with persistent macular fluid on optical coherence tomography despite monthly treatment with at least three consecutive bevacizumab injections followed by at least three ranibizumab injections were prospectively enrolled. A single dexamethasone implant was administered followed by intravitreal ranibizumab 1 week later. Ranibizumab was continued afterward on an as-needed basis. Main outcomes were improvement in central retinal thickness and best-corrected visual acuity. Nineteen patients (19 eyes) were enrolled. There was no significant change in best-corrected visual acuity over 6 months. Greatest reduction in mean central retinal thickness, from 295.2 μm to 236.2 μm, occurred 1 month after dexamethasone implant (P < 0.0001). By Month 6, mean central retinal thickness was 287.3 μm (P = 0.16). Eyes with only intraretinal fluid (13 eyes) achieved a fluid-free macula. Eyes with predominantly subretinal fluid (6 eyes) did not improve central retinal thickness and continued monthly ranibizumab. Mean baseline intraocular pressure was 13.2 mmHg, which peaked at 15.6 mmHg by Month 2 (P = 0.004). Intravitreal dexamethasone implant improved only macular intraretinal fluid in eyes with neovascular age-related macular degeneration resistant to bevacizumab and ranibizumab. However, this treatment had a limited duration.

Synovial aspiration and serological testing in two-stage revision arthroplasty for prosthetic joint infection: evaluation before reconstruction with a mean follow-up of twenty seven months.

PubMed

Mühlhofer, Heinrich M L; Knebel, C; Pohlig, Florian; Feihl, Susanne; Harrasser, Norbert; Schauwecker, Johannes; von Eisenhart-Rothe, Rüdiger

2018-02-01

The two-stage revision protocol is the gold standard for controlling and treating low-grade prosthetic joint infections of total hip and total knee arthroplasty. The antibiotic pause for diagnostic reasons before reconstruction (stage two) is discussed in relation to the persistence of the infection and the development of resistant bacterial strains. Serological markers and a synovial analysis are commonly used to exclude the persistence of infection. Therefore, we asked (1) is the serological testing of C-reactive protein and leucocytes a valuable tool to predict a persistence of infection? and (2) what is the role of synovial aspiration of Plymethylmethacrylat (PMMA) spacers in hip and knee joints? One hundred twelve patients who were MSIS criteria-positive for a prosthetic joint infection were studied, including 45 total hip arthroplasties (THA) and 67 total knee artrhoplasties (TKA) patients. All patients were treated with a two-stage-protocol using a mobile PMMA spacer after a 14-day antibiotic-free interval, during which we measured serological markers (C-reactive protein and leucocytes) and performed synovial aspiration (white blood cell count, polymorphonuclear cell percentage, and microbiological culture) in these patients and compared the results with those of their long-term-follow-up (mean follow-up 27 months, range 24-36 months). Of the 112 patients, 89 patients (79.5%; 95% CI 72-86.9) exhibited infection control after a two-stage exchange, and we detected most methicillin-resistant, coagulase-negative Staphylococci (CoNS) in cases of a persistent infection. The mean sensitivity of serum C-reactive protein in the patients was 0.43 (range 0.23-0.64), and the mean specificity was 0.73 (range 0.64-0.82). For serum leucocytes, the mean sensitivity was 0.09 (range 0-0.29), and the mean specificity was 0.81 (range 0.7-0.92). The mean sensitivity for the WBC count in the synovial fluid (PMMA spacer aspiration) was 0.1 (range 0-0.29), and the mean specificity was 0.79 (range 0.68-0.92). For the PMN percentage, the mean sensitivity was 0.1 (range 0-0.29), and the mean specificity was 0.79 (range 0.68-0.92). No cut-off values could be established for C-reactive protein, leucocytes, WBC count and PMN percentage due to the low AUC. No reliable markers were identified for the long-term persistence of infection. C-reactive protein and leucocytes were often elevated, even when the infection was controlled. In addition, normalized serum markers did not exclude the persistence of infection during follow-up. The synovial analysis of the WBC count and PMN percentage did not predict the persistence of infection. However, microbiological synovial fluid analysis is often misleading due to false positive microbiological cultures, which results in overtreatment.

Mantle hydrous-fluid interaction with Archaean granite.

NASA Astrophysics Data System (ADS)

Słaby, E.; Martin, H.; Hamada, M.; Śmigielski, M.; Domonik, A.; Götze, J.; Hoefs, J.; Hałas, S.; Simon, K.; Devidal, J.-L.; Moyen, J.-F.; Jayananda, M.

2012-04-01

Water content/species in alkali feldspars from late Archaean Closepet igneous bodies as well as growth and re-growth textures, trace element and oxygen isotope composition have been studied (Słaby et al., 2011). Both processes growth and re-growth are deterministic, however they differ showing increasing persistency in element behaviour during interaction with fluids. The re-growth process fertilized domains and didn't change their oxygen-isotope signature. Water speciation showed persistent behaviour during heating at least up to 600oC. Carbonate crystals with mantle isotope signature are associated with the recrystallized feldspar domains. Fluid-affected domains in apatite provide evidence of halide exchange. The data testify that the observed recrystallization was a high-temperature reaction with fertilized, halide-rich H2O-CO2 mantle-derived fluids of high water activity. A wet mantle being able to generate hydrous plumes, which appear to be hotter during the Archean in comparison to the present time is supposed by Shimizu et al. (2001). Usually hot fluids, which can be strongly carbonic, precede asthenospheric mantle upwelling. They are supposed to be parental to most recognized compositions, which can be derived by their immiscible separation into saline aqueous-silicic and carbonatitic members (Klein-BenDavid et al., 2007). The aqueous fractions are halogen-rich with a significant proportion of CO2. Both admixed fractions are supposed to be fertile. The Closepet granite emplaced in a major shear zone that delimitates two different terrains. Generally such shear zones, at many places, are supposed to be rooted deep into the mantle. The drain, that favoured and controlled magma ascent and emplacement, seemed to remain efficient after granite crystallization. In the southern part of the Closepet batholiths an evidence of intensive interaction of a lower crust fluid (of high CO2 activity) is provided by the extensive charnockitization of amphibolite facies (Stähle et al., 1987).The previously published data as well as the new ones point to volatile elements from both mantle and crust playing a prominent role in the petrogenesis of magmatic rocks during the Archaean. Their composition differs significantly in regard to water and CO2 activity. The present contribution gives an evidence of hydrous mantle-derived fluids. Taking under consideration two-end members model proposed for Archaean mantle, the contribution favours wet-mantle model. The work has been done within the framework of IGCP-SIDA 599 and has been funded by IGSci PASci 'Hybrid' and IGSci PASci-CNRS-UMR 6524-LMV project: 'Equilibration and re-equilibration processes in Archaean granites'. Klein-BenDavid, O., Izraeli, E.S., Hauri, E. & Navon, O. (2007). Fluid inclusions in diamonds from the Diavik mine, Canada and the evolution of diamond-forming fluids. Geochimica et Cosmochimica Acta 71, 723-744. Słaby, E., Martin, H., Hamada, M., Śmigielski, M., Domonik, A., Götze, J., Hoefs, J., Hałas, S., Simon, K., Devidal, J-L., Moyen, J-F., Jayananda, M. (2011) Evidence in Archaean alkali-feldspar megacrysts for high-temperature interaction with mantle fluids. Journal of Petrology (on line). doi:10.1093/petrology/egr056. Stähle, H.J., Raith, M., Hoernes, S. & Delfs, A. (1987). Element mobility during incipient granulite formation at Kabbaldurga, Southern India. Journal of Petrology 28, 803-834.

Retrospective cohort study exploring whether an association exists between spatial distribution of cystoid spaces in cystoid macular oedema secondary to retinitis pigmentosa and response to treatment with carbonic anhydrase inhibitors.

PubMed

Strong, Stacey A; Hirji, Nashila; Quartilho, Ana; Kalitzeos, Angelos; Michaelides, Michel

2018-04-29

Carbonic anhydrase inhibitors (CAIs) are frequently used as an initial step to treat retinitis pigmentosa-associated cystoid macular oedema (RP-CMO). Interestingly, it has been postulated that CAIs might reduce outer nuclear layer (ONL) fluid more effectively than inner nuclear layer (INL) fluid due to better access to retinal pigment epithelium basolateral membrane than neurosensory retina. This retrospective cohort study explores if an association between spatial distribution of cystoid spaces in RP-CMO and CAI response exists. Two independent graders reviewed pretreatment and post-treatment optical coherence tomography (OCT) images of 25 patients (43 eyes) initiated on topical and/or oral CAIs between January 2013 and December 2014. Documentation included the presence/absence of fluid (and layer(s) involved), external limiting membrane, epiretinal membrane (ERM), vitreomacular adhesion/traction, lamellar/full-thickness macular hole and central macular thickness (CMT)/volume. INL fluid was found in all study eyes. All 13 'responders' (at least 11% reduction of CMT after treatment) demonstrated pretreatment ONL fluid. In seven patients (four responders and three non-responders), complete clearance of ONL fluid was achieved despite persistence of INL fluid. ERM presence was similar in responders and non-responders. In this study, INL fluid was found to be the most common spatial distribution of RP-CMO. However, patients who were classed as a 'responder' to CAI treatment all demonstrated coexisting ONL fluid on their pretreatment OCT scans. This may be explained by CAIs having better access to retinal pigment epithelium basolateral membrane than neurosensory retina. Our study also suggests a minimal impact on response to CAIs by ERM. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Presence and Persistence of Ebola or Marburg Virus in Patients and Survivors: A Rapid Systematic Review.

PubMed

Brainard, Julii; Pond, Katherine; Hooper, Lee; Edmunds, Kelly; Hunter, Paul

2016-02-01

The 2013-15 Ebola outbreak was unprecedented due to sustained transmission within urban environments and thousands of survivors. In 2014 the World Health Organization stated that there was insufficient evidence to give definitive guidance about which body fluids are infectious and when they pose a risk to humans. We report a rapid systematic review of published evidence on the presence of filoviruses in body fluids of infected people and survivors. Scientific articles were screened for information about filovirus in human body fluids. The aim was to find primary data that suggested high likelihood of actively infectious filovirus in human body fluids (viral RNA). Eligible infections were from Marburg virus (MARV or RAVV) and Zaire, Sudan, Taï Forest and Bundibugyo species of Ebola. Cause of infection had to be laboratory confirmed (in practice either tissue culture or RT-PCR tests), or evidenced by compatible clinical history with subsequent positivity for filovirus antibodies or inflammatory factors. Data were extracted and summarized narratively. 6831 unique articles were found, and after screening, 33 studies were eligible. For most body fluid types there were insufficient patients to draw strong conclusions, and prevalence of positivity was highly variable. Body fluids taken >16 days after onset were usually negative. In the six studies that used both assay methods RT-PCR tests for filovirus RNA gave positive results about 4 times more often than tissue culture. Filovirus was reported in most types of body fluid, but not in every sample from every otherwise confirmed patient. Apart from semen, most non-blood, RT-PCR positive samples are likely to be culture negative and so possibly of low infectious risk. Nevertheless, it is not apparent how relatively infectious many body fluids are during or after illness, even when culture-positive, not least because most test results come from more severe cases. Contact with blood and blood-stained body fluids remains the major risk for disease transmission because of the known high viral loads in blood.

The effects of exposure of susceptible alpacas to alpacas persistently infected with bovine viral diarrhea virus

PubMed Central

Byers, Stacey R.; Evermann, James F.; Bradway, Daniel S.; Grimm, Amanda L.; Ridpath, Julia F.; Parish, Steven M.; Tibary, Ahmed; Barrington, George M.

2011-01-01

Reports of bovine viral diarrhea virus (BVDV) infections in alpacas have been increasing in recent years but much is still unknown about the mechanisms of disease in this species. This report characterizes the transmission of BVDV from persistently infected (PI) alpacas to BVDV naïve alpacas, documents shedding patterns, and characterizes the disease effects in both PI and transiently infected alpacas. Two PI alpacas shed BVDV Type 1b virus in most body fluids, and commonly available diagnostic tests verified their status. Bovine viral diarrhea virus Type 1b transient infections produced only mild signs of disease in BVDV naïve alpacas. Viremia was detected in whole blood, but viral shedding during the acute phase was not detected and antibody appeared to be protective upon re-exposure to the virus. PMID:21629418

Persistent Mullerian duct syndrome in a Miniature Schnauzer dog with signs of feminization and a Sertoli cell tumour.

PubMed

Vegter, A R; Kooistra, H S; van Sluijs, F J; van Bruggen, L W L; Ijzer, J; Zijlstra, C; Okkens, A C

2010-06-01

A 5-year-old male Miniature Schnauzer was presented with unilateral cryptorchidism and signs of feminization. Abdominal ultrasonography revealed an enlarged right testis and a large, fluid-filled cavity that appeared to arise from the prostate. Computed tomography revealed the cavity to be consistent with an enlarged uterine body, arising from the prostate, and showed two structures resembling uterine horns that terminated close to the adjacent testes. The dog had a normal male karyotype, 78 XY. Gonadohysterectomy was performed and both the surgical and the histological findings confirmed the presence of a uterus in this male animal, resulting in a diagnosis of persistent Mullerian duct syndrome (PMDS). The enlarged intra-abdominal testis contained a Sertoli cell tumour. Computed tomography proved to be an excellent diagnostic tool for PMDS.

New daily persistent headache.

PubMed

Tyagi, Alok

2012-08-01

New daily persistent headache (NDPH) is a chronic headache developing in a person who does not have a past history of headaches. The headache begins acutely and reaches its peak within 3 days. It is important to exclude secondary causes, particularly headaches due to alterations in cerebrospinal fluid (CSF) pressure and volume. A significant proportion of NDPH sufferers may have intractable headaches that are refractory to treatment. The condition is best viewed as a syndrome rather than a diagnosis. The headache can mimic chronic migraine and chronic tension-type headache, and it is also important to exclude secondary causes, particularly headaches due to alterations in CSF pressure and volume. A large proportion of NDPH sufferers have migrainous features to their headache and should be managed with treatments used for treating migraine. A small group of NDPH sufferers may have intractable headaches that are refractory to treatment.

Non-adherence in patients on chronic hemodialysis: an international comparison study.

PubMed

Kugler, Christiane; Maeding, Ilona; Russell, Cynthia L

2011-01-01

Adherence to diet and fluid restrictions by adults on hemodialysis treatment is challenging. This study compared non-adherence (NA) to diet and fluid restrictions between adult US and German hemodialysis patients, and assessed potential predictors for NA. A cross-sectional multicenter comparative study of 456 adult hemodialysis patients was conducted in 12 outpatient-based hemodialysis centers in the United States and Germany. NA was based on self-report using the Dialysis Diet and Fluid Non-adherence Questionnaire (DDFQ). Laboratory marker, interdialytic weight gain (IDWG) and dialysis adequacy (Kt/V) information were obtained from medical records. Mean time on dialysis was 50 months (range 3-336); mean age was 62 years (range 19-91), with the majority of patients (89.7%) being white. Self-reported frequency of NA to diet was 80.4% and to fluid 75.3% in the total sample. The degree of NA to diet and fluid differed significantly, with the US patients (68.1% vs. 61.1%) reporting less NA when compared with German (81.6% vs. 79.0%) patients (p<0.0001). Phosphorus, albumin, IDWG and Kt/V levels were higher in the US compared with the German subsample (all p<0.0001; IDWG p<0.003). Generalized regression models revealed that education (p<0.01) and smoking (p<0.01) predicted NA to diet, whereas single marital status (p<0.008) and male sex (p<0.04) were independent predictors for NA to fluid. NA persists as one of the most challenging tasks in health care of patients with chronic conditions, including hemodialysis patients. Our findings suggest that patient, condition-related, socioeconomic and health care system-related factors may contribute to NA to diet and fluid restrictions.

Fire Protection Informational Exchange

DTIC Science & Technology

2016-07-01

0.95 L/min concurrent spray & 274x521 mm pool (66°C) i. Persistent fuels; turbine fuel in spray/pool; lubricant, hydraulic fluid in spray ii...conjugate image plane La Vision sCMOS + Kl long- distance microscope with CF4 objective wire .. " " " " ... in-line hologram image plane La...distance microscope with CF4 objective wire I phase disrurbanc.e (f= 2000 nun) .. " " " " ... in-line hologram image plane La Vision sCNlOS

Host innate inflammatory factors and staphylococcal protein A influence the duration of human Staphylococcus aureus nasal carriage.

PubMed

Cole, A L; Muthukrishnan, G; Chong, C; Beavis, A; Eade, C R; Wood, M P; Deichen, M G; Cole, A M

2016-11-01

Human Staphylococcus aureus (SA) nasal carriage provides a reservoir for the dissemination of infectious strains; however, factors regulating the establishment and persistence of nasal colonization are mostly unknown. We measured carriage duration and nasal fluid inflammatory markers after nasally inoculating healthy participants with their previously isolated SA strains. Out of 15 studies, 10 resulted in rapid clearance (9±6 days) that corresponded with upregulated chemokines, growth factors, and predominantly Th1-type cytokines, but not interleukin (IL)-17. Nasal SA persistence corresponded with elevated baseline levels of macrophage inflammatory protein-1β, IL-1β, and IL-6, no induction of inflammatory factors after inoculation, and decreased IL-1 receptor antagonist/IL-1β ratio. SA-expressed staphylococcal protein A (SpA) levels correlated positively with carriage duration. Competitive inoculation studies revealed that isogenic SpA knockout (ΔSpA) strains were cleared faster than wild type only in participants with upregulated inflammatory markers after inoculation. The remaining participants did not mount an inflammatory response and did not clear either strain. ΔSpA strains demonstrated lower growth rates in carrier nasal fluids and lower survival rates when incubated with neutrophils. Collectively, the presented studies identify innate immune effectors that cooperatively modulate nasal carriage duration, and confirm SpA as a bacterial codeterminant of SA nasal carriage.

Host innate inflammatory factors and staphylococcal protein A influence the duration of human Staphylococcus aureus nasal carriage

PubMed Central

Cole, Amy L.; Muthukrishnan, Gowrishankar; Chong, Christine; Beavis, Ashley; Eade, Colleen R.; Wood, Matthew P.; Deichen, Michael G.; Cole, Alexander M.

2016-01-01

Human Staphylococcus aureus (SA) nasal carriage provides a reservoir for the dissemination of infectious strains; however, factors regulating the establishment and persistence of nasal colonization are mostly unknown. We measured carriage duration and nasal fluid inflammatory markers after nasally inoculating healthy participants with their previously isolated SA strains. Ten out of 15 studies resulted in rapid clearance (9±6 days) that corresponded with upregulated chemokines, growth factors, and predominantly Th1-type cytokines, but not IL-17. Nasal SA persistence corresponded with elevated baseline levels of MIP-1β, IL-1β, and IL-6, no induction of inflammatory factors post-inoculation, and decreased IL-1RA:IL-1β ratio. SA-expressed staphylococcal protein A (SpA) levels correlated positively with carriage duration. Competitive inoculation studies revealed that isogenic SpA knockout (ΔSpA) strains were cleared faster than wild-type only in participants with upregulated inflammatory markers post-inoculation. The remaining participants did not mount an inflammatory response and did not clear either strain. ΔSpA strains demonstrated lower growth rates in carrier nasal fluids and lower survival rates when incubated with neutrophils. Collectively, the presented studies identify innate immune effectors that cooperatively modulate nasal carriage duration, and confirm SpA as a bacterial co-determinant of SA nasal carriage. PMID:26838052

OPPT workplan assessments for medium and long chain ...

EPA Pesticide Factsheets

MCCPs (C14 – C17) and the C18-20 LCCPs are liquid mixtures of chlorinated alkanes. Short chain chlorinated paraffins (SCCPs, C10-C13) have been the focus of coordinated global action (including by US EPA as an action plan chemical), and MCCPs and LCCPs are alternatives to SCCPs for many applications. In the United States, these substances are typically used in oils and metal working fluids to impart stability during high temperature/pressure operations; in plastics/ rubber (PVC) compounding, paints, coatings, adhesives, and sealants as plasticizers and flame retardants. Other assessments have generally found these chemicals to be highly persistent, and some of the congeners are expected to be highly bioaccumulative. MCCPs and LCCPs have been found in all types of environmental media far from their sources, as well as observed in indoor air and house dust, food, fish, human breast milk, and cow’s milk. The assessment will focus on MCCPs (C14-C17) and certain LCCPs (C18-C20) that have received the most international regulatory attention. Based on the screening assessments regarding persistence and bioaccumulation, this assessment will consider PBT aspects of MCCPs and LCCPs, primarily focusing on releases to the environment from the processing and use from metal working fluids and plastics/rubber (PVC) compounding. EPA anticipates issuing draft risk assessments for public review and comment as they are completed. At the conclusion of the review process, if

A Study of Permeability Changes Due to Cold Fluid Circulation in Fractured Geothermal Reservoirs.

PubMed

Gholizadeh Doonechaly, Nima; Abdel Azim, Reda R; Rahman, Sheik S

2016-05-01

Reservoir behavior due to injection and circulation of cold fluid is studied with a shear displacement model based on the distributed dislocation technique, in a poro-thermoelastic environment. The approach is applied to a selected volume of Soultz geothermal reservoir at a depth range of 3600 to 3700 m. Permeability enhancement and geothermal potential of Soultz geothermal reservoir are assessed over a stimulation period of 3 months and a fluid circulation period of 14 years. This study-by shedding light onto another source of uncertainty-points toward a special role for the fracture surface asperities in predicting the shear dilation of fractures. It was also observed that thermal stress has a significant impact on changing the reservoir stress field. The effect of thermal stresses on reservoir behavior is more evident over longer circulation term as the rock matrix temperature is significantly lowered. Change in the fracture permeability due to the thermal stresses can also lead to the short circuiting between the injection and production wells which in turn decreases the produced fluid temperature significantly. The effect of thermal stress persists during the whole circulation period as it has significant impact on the continuous increase in the flow rate due to improved permeability over the circulation period. In the current study, taking into account the thermal stress resulted in a decrease of about 7 °C in predicted produced fluid temperature after 14 years of cold fluid circulation; a difference which notably influences the potential prediction of an enhanced geothermal system. © 2015, National Ground Water Association.

Systemic PPARγ deletion causes severe disturbance in fluid homeostasis in mice

PubMed Central

Zhou, Li; Panasiuk, Alexandra; Downton, Maicy; Zhao, Daqiang; Yang, Baoxue; Jia, Zhanjun

2015-01-01

The pharmacological action of peroxisome proliferator-activated receptor (PPAR)γ in promoting sodium and water retention is well documented as highlighted by the major side-effect of body weight gain and edema associated with thiazolidinedione use. However, a possible physiological role of PPARγ in regulation of fluid metabolism has not been reported by previous studies. Here we analyzed fluid metabolism in inducible whole-body PPARγ knockout mice. The null mice developed severe polydipsia and polyuria, reduced urine osmolality, and modest hyperphagia. The phenomenon persisted during 3 days of pair feeding and pair drinking, accompanied by progressive weight loss. After 24 h water deprivation, the null mice had a lower urine osmolality, a higher urine volume, a greater weight loss, and a greater rise in hematocrit than the floxed control. Urinary vasopressin (AVP) excretion was not different between the genotypes under basal condition or after WD. The response of urine osmolality to acute and chronic 1-desamino-8-d-arginine vasopressin treatment was attenuated in the null mice, but the total abundance or phosphorylation of aquaporin 2 (AQP2) in the kidney or AVP-induced cAMP production in inner medullary collecting duct suspensions was unaffected. Overall, PPARγ participates in physiological control of fluid homeostasis through an unknown mechanism involving cAMP/AQP2-independent enhancement of AVP response. PMID:26330489

Determination of methylglyoxal-bis(guanylhydrazone) in body fluids by ion-pair chromatography.

PubMed

Roboz, J; Wu, K T; Hart, R D

1980-01-01

Methylglyoxal-bis(guanylhydrazone), Methyl-G, is a potent antineoplastic agent currently undergoing Phase l clinical trials. Serum, ascitic and pleural fluids, and urine are deproteinized with methanol, supernatant is evaporated, residue is redissolved in the eluent, lipids are removed with carbon tetrachloride, and an aliquot of the aqueous layer injected into the chromatograph. Ethylglyoxal-bis(guanylhydrazone) (Ethyl-G) is the internal standard. The mobile phase is a mixture of an aqueous buffer (containing 0.004 M heptane and pentane sulfonic acid, 90%:10%, buffered to pH 3.5) and methanol (68%:32%). The ion-pair complex is retained on a micro Bondapak C18 column, eluted with a flow of 2.0 mL/min. Absorbance is measured at 280 nm. Detectability: 30 ng/mL (0.11 micro M) in serum, ascitic and pleural fluids, 300 ng/mL (1.1 micro M) in urine. Calibration curves (peak height ratios of Methyl-G/Ethyl-G plotted against known drug concentrations) were linear in the 0.1-30 microg/mL range. Correlation coefficinets were 0.999; coefficients of variation for reproducibility were less than 5%. Residual blood levels of Methyl-G persist for several days. Methyl-G was found to pass into ascitic fluid.

Cognitive and personality factors in the delay of gratification of hemodialysis patients.

PubMed

Rosenbaum, M; Ben-Ari Smira, K

1986-08-01

On the basis of Mischel's (1984) social learning analysis of the process of delay of gratification in children and in line with Bandura's (1977) self-efficacy theory, we developed a model of delay of gratification in adults and tested it on dialysis patients who were continuously required to comply with a stringent regimen of fluid-intake to keep alive. We hypothesized that patients' self-evaluations of their past compliance and their efficacy expectations would be associated with their actual delay behavior. Underlying these process-regulating cognitions would be stable competencies, such as learned resourcefulness (i.e., one's self-control skills). Fifty-three dialysis patients self-evaluated their fluid intake compliance, their efficacy expectations, and their health beliefs. Resourcefulness was assessed by Rosenbaum's Self-Control Schedule. Actual fluid-intake compliance was reliably assessed by the mean body weight increase between dialyses during the 3-month period prior to the study and during two follow-up periods. The results supported the model. On the one hand, self-efficacy expectations were related to persistence with the fluid diet and on the other hand to subjects' self-evaluation of their past adherence behavior as well as to their resourcefulness. Although the path model suggested a causal pattern, the correlational nature of the study precluded any conclusions on cause-effect relationship.

Mitochondrial DNA in Residual Leukemia Cells in Cerebrospinal Fluid in Children with Acute Lymphoblastic Leukemia

PubMed Central

Egan, Kathryn; Kusao, Ian; Troelstrup, David; Agsalda, Melissa; Shiramizu, Bruce

2010-01-01

This feasibility study was designed to assess the ability to measure mitochondrial DNA (mtDNA) in cerebrospinal fluid (CSF) cells that contributed to minimal disease/persistent or residual disease (MD/PRD) from children with acute lymphoblastic leukemia (ALL). Increase in mtDNA copies in cancer cells has been suggested to play a role in MD/PRD. CSF as well as blood specimens from 6 children were assayed for MD/PRD and mtDNA copy numbers by quantitative real-time polymerase chain reaction. Of 7 MD/PRD-positive specimens, 6 had increased mtDNA copy numbers; while 11 MD/PRD-negative specimens had no increase in mtDNA copy numbers, p < 0.003. This is the first proof-of-concept study to measure mtDNA copy numbers in MD/PRD-positive CSF specimens from children with ALL. Increase of mtDNA copy numbers in MD/PRD childhood ALL cells and its significance as a mechanism for recurrence requires further investigation. Keywords Minimal residual disease; Acute lymphoblastic leukemia; Central nervous system; Cerebrospinal fluid; Mitochondria PMID:21331151

Near-Surface Transport Pathways in the North Atlantic Ocean: Looking for Throughput from the Subtropical to the Subpolar Gyre

NASA Astrophysics Data System (ADS)

Rypina, I. I.; Pratt, L. J.; Lozier, M.

2011-12-01

Motivated by discrepancies between Eulerian transport estimates and the behavior of Lagrangian surface drifters, near-surface transport pathways and processes in the North Atlantic are studied using a combination of data, altimetric surface heights, statistical analysis of trajectories, and dynamical systems techniques. Particular attention is paid to the issue of the subtropical-to-subpolar intergyre fluid exchange. The velocity field used in this study is composed of a steady drifter-derived background flow, upon which a time-dependent altimeter-based perturbation is superimposed. This analysis suggests that most of the fluid entering the subpolar gyre from the subtropical gyre within two years comes from a narrow region lying inshore of the Gulf Stream core, whereas fluid on the offshore side of the Gulf Stream is largely prevented from doing so by the Gulf Stream core, which acts as a strong transport barrier, in agreement with past studies. The transport barrier near the Gulf Stream core is robust and persistent from 1992 until 2008. The qualitative behavior is found to be largely independent of the Ekman drift.

Disentangling Random Motion and Flow in a Complex Medium

PubMed Central

Koslover, Elena F.; Chan, Caleb K.; Theriot, Julie A.

2016-01-01

We describe a technique for deconvolving the stochastic motion of particles from large-scale fluid flow in a dynamic environment such as that found in living cells. The method leverages the separation of timescales to subtract out the persistent component of motion from single-particle trajectories. The mean-squared displacement of the resulting trajectories is rescaled so as to enable robust extraction of the diffusion coefficient and subdiffusive scaling exponent of the stochastic motion. We demonstrate the applicability of the method for characterizing both diffusive and fractional Brownian motion overlaid by flow and analytically calculate the accuracy of the method in different parameter regimes. This technique is employed to analyze the motion of lysosomes in motile neutrophil-like cells, showing that the cytoplasm of these cells behaves as a viscous fluid at the timescales examined. PMID:26840734

Normal brain tissue volumes after long-term recovery in anorexia and bulimia nervosa.

PubMed

Wagner, Angela; Greer, Phil; Bailer, Ursula F; Frank, Guido K; Henry, Shannan E; Putnam, Karen; Meltzer, Carolyn C; Ziolko, Scott K; Hoge, Jessica; McConaha, Claire; Kaye, Walter H

2006-02-01

Individuals who are ill with anorexia (AN) and bulimia nervosa (BN) often have increased cerebrospinal fluid (CSF) volumes and decreased total gray and white matter volumes. It is unclear whether such disturbances persist after recovery from an eating disorder. Magnetic resonance imaging was performed on 40 women who were long-term recovered (>1 year no binging, purging, or restricting behaviors, normal weight, and menstrual cycles, not on medication) from restricting or binge/purging type AN or BN and 31 healthy control women (CW). Voxel-based morphometry (VBM) was used for data analysis. Recovered AN and BN subgroups were similar to CW in terms of cerebrospinal fluid (CSF) volume as well as total or regional gray or white matter volume. These findings suggest that structural brain abnormalities are reversible in individuals with eating disorders after long-term recovery.

Neuropathogenesis of HIV-associated neurocognitive disorders: roles for immune activation, HIV blipping and viral tropism.

PubMed

Chen, Maria F; Gill, Alexander J; Kolson, Dennis L

2014-11-01

The purpose of this study is to discuss why HIV-associated neurocognitive disorders (HAND) persist despite apparently effective HIV suppression by highly active antiretroviral therapy (ART). As many as 50% of HIV-infected individuals suffer from HAND despite ART suppression of HIV replication to apparently undetectable levels in most treated individuals. Prior to ART, HIV-associated dementia (HAD), the severest form of HAND, affected nearly 20% of infected individuals; HAD now affects only nearly 2% of ART-treated persons, although less severe HAND forms persist. Recent studies link persistent immune activation, inflammation and viral escape/blipping in ART-treated individuals, as well as comorbid conditions, to HIV disease progression and increased HAND risk. Despite sustained HIV suppression in most ART-treated individuals, indicated by routine plasma monitoring and occasional cerebrospinal fluid (CSF) monitoring, 'blips' of HIV replication are often detected with more frequent monitoring, thus challenging the concept of viral suppression. Although the causes of HIV blipping are unclear, CSF HIV blipping associates with neuroinflammation and, possibly, central nervous system (CNS) injury. The current theory that macrophage-tropic HIV strains within the CNS predominate in driving HAND and these associated factors is now also challenged. Protection of the CNS by ART is incomplete, probably due to combined effects of incomplete HIV suppression, persistent immune activation and host comorbidity factors. Adjunctive therapies to ART are necessary for more effective protection.

Zika Virus Persistently Infects and Is Basolaterally Released from Primary Human Brain Microvascular Endothelial Cells.

PubMed

Mladinich, Megan C; Schwedes, John; Mackow, Erich R

2017-07-11

Zika virus (ZIKV) is a mosquito-borne Flavivirus that has emerged as the cause of encephalitis and fetal microencephaly in the Americas. ZIKV uniquely persists in human bodily fluids for up to 6 months, is sexually transmitted, and traverses the placenta and the blood-brain barrier (BBB) to damage neurons. Cells that support persistent ZIKV replication and mechanisms by which ZIKV establishes persistence remain enigmatic but central to ZIKV entry into protected neuronal compartments. The endothelial cell (EC) lining of capillaries normally constrains transplacental transmission and forms the BBB, which selectively restricts access of blood constituents to neurons. We found that ZIKV (strain PRVABC59) persistently infects and continuously replicates in primary human brain microvascular ECs (hBMECs), without cytopathology, for >9 days and following hBMEC passage. ZIKV did not permeabilize hBMECs but was released basolaterally from polarized hBMECs, suggesting a direct mechanism for ZIKV to cross the BBB. ZIKV-infected hBMECs were rapidly resistant to alpha interferon (IFN-α) and transiently induced, but failed to secrete, IFN-β and IFN-λ. Global transcriptome analysis determined that ZIKV constitutively induced IFN regulatory factor 7 (IRF7), IRF9, and IFN-stimulated genes (ISGs) 1 to 9 days postinfection, despite persistently replicating in hBMECs. ZIKV constitutively induced ISG15, HERC5, and USP18, which are linked to hepatitis C virus (HCV) persistence and IFN regulation, chemokine CCL5, which is associated with immunopathogenesis, as well as cell survival factors. Our results reveal that hBMECs act as a reservoir of persistent ZIKV replication, suggest routes for ZIKV to cross hBMECs into neuronal compartments, and define novel mechanisms of ZIKV persistence that can be targeted to restrict ZIKV spread. IMPORTANCE ZIKV persists in patients, crossing placental and neuronal barriers, damaging neurons, and causing fetal microencephaly. We found that ZIKV persistently infects brain endothelial cells that normally protect neurons from viral exposure. hBMECs are not damaged by ZIKV infection and, analogous to persistent HCV infection, ZIKV constitutively induces and evades antiviral ISG and IFN responses to continuously replicate in hBMECs. As a result, hBMECs provide a protective niche for systemic ZIKV spread and a viral reservoir localized in the normally protective blood-brain barrier. Consistent with the spread of ZIKV into neuronal compartments, ZIKV was released basolaterally from hBMECs. Our findings define hBMEC responses that contribute to persistent ZIKV infection and potential targets for clearing ZIKV infections from hBMECs. These results further suggest roles for additional ZIKV-infected ECs to facilitate viral spread and persistence in the protected placental, retinal, and testicular compartments. Copyright © 2017 Mladinich et al.

Carbonatitic liquids and COH fluids from epidote-dolomite eclogites at 3.7 - 4.6 GPa: new perspectives on carbon transfer at subduction zones

NASA Astrophysics Data System (ADS)

Poli, S.

2013-12-01

Current knowledge on the solidus temperature for carbonate-bearing rocks suggests that carbonatitic liquids should not form in a subducted oceanic lithosphere, unless anomalous thermal relaxation occurs. For a mildly warm subduction path, COH-bearing basaltic eclogites are expected to loose all H2O component at epidote breakdown, located at approx. 2.8-3.0 GPa. Above this pressure limit, the solidus is that of a carbonated basaltic eclogite which shows a minimum temperature of 1020 °C at 4.0-4.5 GPa (Dasgupta et al. 2004). However, the oceanic crust includes a range of gabbroic rocks, altered on rifts and transforms, with large amounts of An-rich plagioclase. It has been shown that epidote disappearance with pressure depend on the normative anorthite content of the bulk composition considered (Poli et al. 2009); we therefore expect that altered gabbros might display a much wider pressure range where epidote persists, potentially affecting the solidus relationships. Notably, this applies to epidosite rocks formed in hydrothermal environments at oceanic settings, then recovered in high-pressure and ultra-high pressure terrains. New experimental data from 3.7 to 4.6 GPa, 750°C to 1000 °C are intended to unravel the effect of variable bulk and volatile compositions in model eclogites, enriched in the normative anorthite component (An37 and An45). Experiments are performed in piston cylinder and multianvil machines apparatus, using both single and, buffered, double capsule techniques. Garnet, clinopyroxene and coesite form in all syntheses. Lawsonite was found to persist at 3.7 GPa, 750 °C, with both dolomite and magnesite; at 3.8 GPa, 775-800 °C, fluid saturated conditions, epidote coexists with kyanite, dolomite and magnesite. The anhydrous assemblage garnet, omphacite, aragonite, kyanite is found at 4.2 GPa, 850 °C. At 900 °C, fluid-rich conditions, a silicate fluid/melt of granitoid composition, a carbonatitic melt and Na-carbonate are observed. Close to fluid-saturation, 3.8-4.2 GPa, 900 °C, garnet and Na-rich clinopyroxene coexist with a carbonatitic melt and dolomite. The carbonatitic melt is richer in Ca compared to dolomite, consistently with phase relationships in the model system MgCO3-FeCO3-CaCO3. In fluid-undersaturated compositions, fluid-absent melting of epidote + dolomite, enlarged in its pressure stability for An-rich gabbros, is expected to promote the generation of carbonatitic liquids. The subsolidus breakdown of epidote in the presence of carbonates at depths exceeding 120 km provides a major source of COH fluids at subarc depth. In warm subduction zones, the possibility of extracting carbonatitic liquids from a variety of gabbroic rocks and epidosites offers new scenarios on the metasomatic processes in the lithospheric wedge of subduction zones and a new mechanism for recycling carbon. Dasgupta R., Hirschmann M.M., Withers A. (2004) Earth Planet Sci Lett, 227: 73-85 Poli S., Franzolin E., Fumagalli P., Crottini A. (2009) Earth Planet Sci Lett, 278: 350-360

Chikungunya Arthritis Mechanisms in the Americas (CAMA): A cross sectional analysis of chikungunya arthritis patients 22 months post-infection demonstrates a lack of viral persistence in synovial fluid

DTIC Science & Technology

2017-06-30

Chikungunya Arthritis Mechanisms in the Americas (CAMA): 1 A cross-sectional analysis of chikungunya arthritis patients 22-months post -infection...school or less level of education (94%). CHIKV arthritis 58 patients (Median 22-months (IQR 21-23) post -CHIKV infection) had moderate disease...rheumatoid arthritis are being tested in this patient population. However, such therapeutics could be 76 dangerous if active virus is still present

Enterocutaneous fistulas: an overview.

PubMed

Whelan, J F; Ivatury, R R

2011-06-01

Enterocutaneous fistulas remain a difficult management problem. The basis of management centers on the prevention and treatment of sepsis, control of fistula effluent, and fluid and nutritional support. Early surgery should be limited to abscess drainage and proximal defunctioning stoma formation. Definitive procedures for a persistent fistula are indicated in the late postoperative period, with resection of the fistula segment and reanastomosis of healthy bowel. Even more complex are the enteroatmospheric fistulas in the open abdomen. These enteric fistulas require the highest level of multidisciplinary approach for optimal outcomes.

Identification of Curvularia lunata by polymerase chain reaction in a case of fungal endophthalmitis.

PubMed

Alex, Deepu; Li, Dongmei; Calderone, Richard; Peters, Stephen M

2013-08-09

Curvularia is a dematiaceous mold that infects plant species and is found in the soil. In humans, it is known to cause keratitis after trauma to the eye. We report the findings of persistent fungal endophthalmitis in a 74-year-old female patient who had undergone prior cataract surgery. Mold identification and antifungal susceptibilities were done on 2 separate samples of vitreous fluid and they were found to be consistent with Curvularia lunata by the use of PCR amplification methods.

Early Jurassic clay authigenesis in the Central Appalachian Valley and Ridge province; infiltration of surface-derived fluids during Pangean rifting

NASA Astrophysics Data System (ADS)

Lynch, E. A.; van der Pluijm, B.; Vennemann, T. W.

2017-12-01

The eastern margin of North America has a protracted and intricate tectonic history. The terminal collision of Gondwana and Laurentia in the late Paleozoic formed the Appalachian mountain belt, a trans-continental orogen that persisted for almost 100 million years until Mesozoic break-up of the supercontinent Pangea. A host of studies have targeted the evolution and migration of fluids through Appalachian crust in an effort to understand how fluid promotes mass and heat redistribution, and mediates crustal deformation, particularly during the assembly of Pangea. Folded clay units from the Central Appalachian Valley and Ridge province were sampled for stable and radiogenic isotope analysis. Separation of samples into different grain-size fractions characterizes detrital (host) and authigenic (neomineralized) clays. Stable H-isotope compositions reveal a systematic pattern with varying proportions of illite polytypes—the finer, younger fraction is D-depleted compared to the coarser, primarily detrital fraction. For each individual location, the H-isotopic composition of the fluid from which the authigenic population was grown is calculated. δDVSMOW of these fluids has a range from -77 to -52 ± 2 ‰, consistent with a surface-derived fluid source. The notably negative values for several samples indicates a meteoric composition of moderate to high elevation origin, suggesting that they are not connate waters, but instead preserve infiltration of fluids due to fracture-induced permeability. Key to this interpretation is 40Ar/39Ar-dating of a subset of these samples that reveals a post-orogenic age for authigenic clay mineralization in the Early Jurassic ( 180 Ma). These ages are evidence that surface fluid infiltration was unrelated to the Appalachian orogeny, but coeval with (upper) crustal extension from the initial break-up of Pangea and the emplacement of the Central Atlantic Magmatic Province.

Shape effects of filaments versus spherical particles in flow and drug delivery

PubMed Central

GENG, YAN; DALHAIMER, PAUL; CAI, SHENSHEN; TSAI, RICHARD; TEWARI, MANORAMA; MINKO, TAMARA; DISCHER, DENNIS E.

2009-01-01

Interaction of spherical particles with cells and within animals has been studied extensively, but the effects of shape have received little attention. Here we use highly stable, polymer micelle assemblies known as filomicelles to compare the transport and trafficking of flexible filaments with spheres of similar chemistry. In rodents, filomicelles persisted in the circulation up to one week after intravenous injection. This is about ten times longer than their spherical counterparts and is more persistent than any known synthetic nanoparticle. Under fluid flow conditions, spheres and short filomicelles are taken up by cells more readily than longer filaments because the latter are extended by the flow. Preliminary results further demonstrate that filomicelles can effectively deliver the anticancer drug paclitaxel and shrink human-derived tumours in mice. Although these findings show that long-circulating vehicles need not be nanospheres, they also lend insight into possible shape effects of natural filamentous viruses. PMID:18654271

Shape effects of filaments versus spherical particles in flow and drug delivery

NASA Astrophysics Data System (ADS)

Geng, Yan; Dalhaimer, Paul; Cai, Shenshen; Tsai, Richard; Tewari, Manorama; Minko, Tamara; Discher, Dennis E.

2007-04-01

Interaction of spherical particles with cells and within animals has been studied extensively, but the effects of shape have received little attention. Here we use highly stable, polymer micelle assemblies known as filomicelles to compare the transport and trafficking of flexible filaments with spheres of similar chemistry. In rodents, filomicelles persisted in the circulation up to one week after intravenous injection. This is about ten times longer than their spherical counterparts and is more persistent than any known synthetic nanoparticle. Under fluid flow conditions, spheres and short filomicelles are taken up by cells more readily than longer filaments because the latter are extended by the flow. Preliminary results further demonstrate that filomicelles can effectively deliver the anticancer drug paclitaxel and shrink human-derived tumours in mice. Although these findings show that long-circulating vehicles need not be nanospheres, they also lend insight into possible shape effects of natural filamentous viruses.

Persistence of Polydimethylsiloxane Condom Lubricants.

PubMed

Tottey, Leah S; Coulson, Sally A; Wevers, Gerhard E; Fabian, Laura; McClelland, Heather; Dustin, Mickayla

2018-05-14

Polydimethylsiloxane (PDMS) is commonly used to lubricate condoms. The detection of PDMS on swabs from complainants can be used to support an allegation of sexual assault. Previous research has focused on establishing analytical techniques for detecting PDMS. This research examined the persistence of PDMS on the penis, in the vagina, in the mouth, and on skin. The longest PDMS detection times were 20 h on the penis, 35 h in the vagina, and 52 h on skin. PDMS was detected up to 4 h in the mouth if the participant did not eat or drink and up to 9 h if the participant slept. PDMS was not detected in the mouth after eating or drinking. The presence of biological fluids had no detrimental effect on the analysis. Aqueous extraction of swabs for DNA did not remove any significant amount of PDMS; hence, swab remains could be subsequently analyzed for PDMS. © 2018 American Academy of Forensic Sciences.

New daily persistent headache

PubMed Central

Tyagi, Alok

2012-01-01

New daily persistent headache (NDPH) is a chronic headache developing in a person who does not have a past history of headaches. The headache begins acutely and reaches its peak within 3 days. It is important to exclude secondary causes, particularly headaches due to alterations in cerebrospinal fluid (CSF) pressure and volume. A significant proportion of NDPH sufferers may have intractable headaches that are refractory to treatment. The condition is best viewed as a syndrome rather than a diagnosis. The headache can mimic chronic migraine and chronic tension-type headache, and it is also important to exclude secondary causes, particularly headaches due to alterations in CSF pressure and volume. A large proportion of NDPH sufferers have migrainous features to their headache and should be managed with treatments used for treating migraine. A small group of NDPH sufferers may have intractable headaches that are refractory to treatment. PMID:23024565

Screening of pregnant women for hepatitis B.

PubMed

Boxall, E

1998-11-01

Neonatal infection with hepatitis B virus carries a very high risk of resulting in a persistent infection. Babies born to hepatitis B carrier mothers are at risk of infection through exposure to blood and body fluids during birth. These 'at risk' babies can only be identified through screening of all mothers during pregnancy. Prevention of infection in this group is a key element in any nation's strategy to reduce the incidence and eventually eliminate hepatitis B infection in its population as the persistently infected infants are a reservoir of infection throughout their lives. The infected adult carries a relatively low risk of becoming a chronic carrier (< 10%). Various strategies for screening in pregnancy have been adopted. These include attempts to identify women with a history of 'risk behaviour', testing only women who were born in areas of high endemicity, pooling of sera and universal antenatal screening. The advantages and disadvantages of the various strategies will be discussed.

Cerebrospinal fluid cyto-/chemokine profile during acute herpes simplex virus induced anti-N-methyl-d-aspartate receptor encephalitis and in chronic neurological sequelae.

PubMed

Kothur, Kavitha; Gill, Deepak; Wong, Melanie; Mohammad, Shekeeb S; Bandodkar, Sushil; Arbunckle, Susan; Wienholt, Louise; Dale, Russell C

2017-08-01

To examine the cytokine/chemokine profile of cerebrospinal fluid (CSF) during acute herpes simplex virus-induced N-methyl-d-aspartate receptor (NMDAR) autoimmunity and in chronic/relapsing post-herpes simplex virus encephalitis (HSE) neurological syndromes. We measured longitudinal serial CSF cyto-/chemokines (n=34) and a glial marker (calcium-binding astroglial protein, S100B) in one patient during acute HSE and subsequent anti-NMDAR encephalitis, and compared the results with those from two patients with anti-NMDAR encephalitis without preceding HSE. We also compared cyto-/chemokines in cross-sectional CSF samples from three children with previous HSE who had ongoing chronic or relapsing neurological symptoms (2yr 9 mo-16y after HSE) with those in a group of children having non-inflammatory neurological conditions (n=20). Acute HSE showed elevation of a broad range of all T-helper-subset-related cyto-/chemokines and S100B whereas the post-HSE anti-NMDAR encephalitis phase showed persistent elevation of two of five T-helper-1 (chemokine [C-X-C motif] ligand 9 [CXCL9], CXCL10), three of five predominantly B-cell (CXCL13, CCL19, a proliferation-inducing ligand [APRIL])-mediated cyto-/chemokines, and interferon-α. The post-HSE anti-NMDAR encephalitis inflammatory response was more pronounced than anti-NMDAR encephalitis. All three chronic post-HSE cases showed persistent elevation of CXCL9, CXCL10, and interferon-α, and there was histopathological evidence of chronic lymphocytic inflammation in one biopsied case 7 years after HSE. Two of three chronic cases showed a modest response to immune therapy. HSE-induced anti-NMDAR encephalitis is a complex and pronounced inflammatory syndrome. There is persistent CSF upregulation of cyto-/chemokines in chronic or relapsing post-HSE neurological symptoms, which may be modifiable with immune therapy. The elevated cyto-/chemokines may be targets of monoclonal therapies. © 2017 Mac Keith Press.

Ultra-sensitive in-situ detection of near-infrared persistent luminescent tracer nanoagents in crude oil-water mixtures.

PubMed

Chuang, Yen-Jun; Liu, Feng; Wang, Wei; Kanj, Mazen Y; Poitzsch, Martin E; Pan, Zhengwei

2016-06-15

Current fluorescent nanoparticles-based tracer sensing techniques for oilfield applications suffer from insufficient sensitivity, with the tracer detection limit typically at the several hundred ppm level in untreated oil/water mixtures, which is mainly caused by the interference of the background fluorescence from the organic residues in crude oil under constant external excitation. Here we report the use of a persistent luminescence phenomenon, which enables an external excitation-free and thus background fluorescence-free measurement condition, for ultrahigh-sensitivity crude oil sensing. By using LiGa5O8:Cr(3+) near-infrared persistent luminescent nanoparticles as a tracer nanoagent, we achieved a tracer detection limit at the single-digit ppb level (down to 1 ppb concentration of nanoparticles) in high oil fraction (up to 65 wt.%) oil/water mixtures via a convenient, CCD camera-based imaging technique without any pretreatment or phase separation of the fluid samples. This detection limit is about four to five orders of magnitude lower than that obtained using conventional spectral methods. This study introduces a new type of tracer nanoagents and a new detection method for water tracer sensing in oil reservoir characterization and management.

Biophysics of Biofilm Infection

PubMed Central

Stewart, Philip S.

2014-01-01

This article examines a likely basis of the tenacity of biofilm infections that has received relatively little attention: the resistance of biofilms to mechanical clearance. One way that a biofilm infection persists is by withstanding the flow of fluid or other mechanical forces that work to wash or sweep microorganisms out of the body. The fundamental criterion for mechanical persistence is that the biofilm failure strength exceeds the external applied stress. Mechanical failure of the biofilm and release of planktonic microbial cells is also important in vivo because it can result in dissemination of infection. The fundamental criterion for detachment and dissemination is that the applied stress exceeds the biofilm failure strength. The apparent contradiction for a biofilm to both persist and disseminate is resolved by recognizing that biofilm material properties are inherently heterogeneous. There are also mechanical aspects to the ways that infectious biofilms evade leukocyte phagocytosis. The possibility of alternative therapies for treating biofilm infections that work by reducing biofilm cohesion could: 1) allow prevailing hydrodynamic shear to remove biofilm, 2) increase the efficacy of designed interventions for removing biofilms, 3) enable phagocytic engulfment of softened biofilm aggregates, and 4) improve phagocyte mobility and access to biofilm. PMID:24376149

Surgical Management of Complications Associated With Percutaneous and/or Endoscopic Management of Pseudocyst of the Pancreas

PubMed Central

Nealon, William H.; Walser, Eric

2005-01-01

Objective: To study the magnitude of complications associated with the nonoperative management of peripancreatic fluid collections and pseudocysts and to assess the surgical management of these complications. These are compared with complications associated with operative management. Summary Background Data: Pancreatic pseudocysts and peripancreatic fluid collections associated with acute pancreatitis have been managed with success using nonoperative techniques for more than a decade. When successful, these techniques have clear advantages compared with operative management. There has, however, been little focus on the magnitude and outcomes after complications sustained by nonoperative management. Our report focuses on these complications and pseudocysts and on the surgical management. We have been struck by the high percentage of patients who sustain significant and at times life-threatening complications related to the nonoperative management of fluid collections. We further define an association between the main pancreatic ductal anatomy and the likelihood of major complications after nonoperative management. Methods: Between 1992 and 2003, all patients admitted to our service with peripancreatic fluid collections or pseudocysts were monitored. We evaluated complications patients managed with percutaneous (PD) or endoscopic drainage (E). Data were collected regarding patient characteristics, need for intensive care unit (ICU) stays, hemorrhage, hypotension, renal failure, and ventilator support. We further focused on the duration of fistula drainage from patients who have had a percutaneous drainage, and we assessed the necessity for urgent or emergent operation. By protocol, all patients had pancreatic ductal anatomy evaluated by means of endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP). Patients with complications of E and PD were compared with 100 consecutive patients who underwent operative management of pseudocyst and fluid collections as their sole mode of intervention. Results: A total of 79 patients with complications of PD, E, or both were studied. There were 41 males and 38 females in the group of patients who sustained complications (mean age 49 years). Sixty-six of the 79 subsequently required operation to manage their peripancreatic fluid collection, 37 urgent or emergent. The mean elapsed time from diagnosis to nonoperative intervention was 18.1 days. This group of 79 patients had mean 3.1 ± 0.7 hospitalization (range, 1–7) and length-of-stay 42.7 ± 4.1 days. ICU stays were required in 36 of the 79 (46%). A defined episode of clinical sepsis was identified in 72 of 79 (91%) and was by far the most common complication. Hemorrhage requiring transfusion was identified in 16 of the 79 (20%), clinical shock 51 of the 79 (65%), renal failure 16 of the 79 (20%), ventilator support for longer than 24 hours 19 of the 79 (24%). A persistent pancreatic fistula occurred in 66 of the 79 patients (84%); mean duration was 61.4 ± 9.6 days. Sixty-three of the 79 patients with complications of E or PD had ductal anatomy (ERCP/MRCP) which predicted failure because of significant disruption or stenosis of the main pancreatic duct. Among the 100 operated patients, 69 complications occurred in 6 of the 100 (6%). Operation was initiated electively a mean interval of 42.7 days after diagnosis of pseudocyst. Hemorrhage, hypotension, renal failure, sepsis, persistent fistula, or urgent operation all were not seen in the complications associated with operated patients. CT imaging obtained at least 6 months after intervention documented complete resolution after surgery alone in 91 and 9 with cystic structures less than 2 cm. In patients with operation after failed nonoperative therapy, 6 patients had persistent cystic lesions less than 2 cm in diameter. Conclusion: These data support the premise that a choice between operative and nonoperative management for peripancreatic fluid collections and pseudocysts should be made with careful assessment of the pancreatic ductal anatomy, with a clear recognition of the magnitude of complications which are likely to occur should nonoperative measures be used in patients most likely to sustain complications. It is vital to recognize the magnitude and severity of complications of nonoperative measures as one chooses a modality. Ductal anatomy predicts patients who will have complications or failure of management of their peripancreatic fluid collection. PMID:15912044

Thresholds of Transient Cavitation Produced by Pulsed Ultrasound in a Controlled Nuclei Environment.

NASA Astrophysics Data System (ADS)

Holland, Christy Katherine Smith

The possibility of hazardous bioeffects from medical ultrasound examinations and therapy, although not demonstrated in current epidemiologic data, is still of interest to the medical community. In particular, concern persists over the potential of damage at the cellular level due to transient cavitation produced by diagnostic and high intensity therapeutic ultrasound. Transient cavitation is a discrete phenomenon which relies on the existence of stabilized nuclei, or pockets of gas within a host fluid, for its genesis. A convenient descriptor for assessing the likelihood of transient cavitation is the threshold pressure, or the minimum acoustic pressure necessary to initiate bubble growth and subsequent collapse. Experimental measurements of cavitation thresholds are presented here which elucidate the importance of ultrasound host fluid and nuclei parameters in determining these thresholds. These results are interpreted in the context of an approximate theory, included as an appendix, describing the relationship between these parameters and cavitation threshold pressures. An automated experimental apparatus has been developed to determine thresholds for cavitation produced in a fluid by short tone bursts of ultrasound at 0.76, 0.99, and 2.30 MHz. A fluid jet was used to convect potential cavitation nuclei through the focal region of the insonifying transducer. Potential nuclei tested include 1mum polystyrene spheres, microbubbles in the 1-10 μm range that are stabilized with human serum albumin, and whole blood constituents. Cavitation was detected by a passive acoustical technique which is sensitive to sound scattered from cavitation bubbles. Measurements of the transient cavitation threshold in water, in a fluid of higher viscosity, and in diluted whole blood are presented. Results from these experiments which permit the control of nuclei and host fluid properties are compared to the approximate analytical theory for the prediction of the onset of cavitation.

A computational model of amoeboid cell swimming

NASA Astrophysics Data System (ADS)

Campbell, Eric J.; Bagchi, Prosenjit

2017-10-01

Amoeboid cells propel by generating pseudopods that are finger-like protrusions of the cell body that continually grow, bifurcate, and retract. Pseudopod-driven motility of amoeboid cells represents a complex and multiscale process that involves bio-molecular reactions, cell deformation, and cytoplasmic and extracellular fluid motion. Here we present a 3D model of pseudopod-driven swimming of an amoeba suspended in a fluid without any adhesion and in the absence of any chemoattractant. Our model is based on front-tracking/immersed-boundary methods, and it combines large deformation of the cell, a coarse-grain model for molecular reactions, and cytoplasmic and extracellular fluid flow. The predicted shapes of the swimming cell from our model show similarity with experimental observations. We predict that the swimming behavior changes from random-like to persistent unidirectional motion, and that the swimming speed increases, with increasing cell deformability and protein diffusivity. The unidirectionality in cell swimming is observed without any external cues and as a direct result of a change in pseudopod dynamics. We find that pseudopods become preferentially focused near the front of the cell and appear in greater numbers with increasing cell deformability and protein diffusivity, thereby increasing the swimming speed and making the cell shape more elongated. We find that the swimming speed is minimum when the cytoplasm viscosity is close to the extracellular fluid viscosity. We further find that the speed increases significantly as the cytoplasm becomes less viscous compared with the extracellular fluid, resembling the viscous fingering phenomenon observed in interfacial flows. While these results support the notion that softer cells migrate more aggressively, they also suggest a strong coupling between membrane elasticity, membrane protein diffusivity, and fluid viscosity.

TGF-β directs trafficking of the epithelial sodium channel ENaC which has implications for ion and fluid transport in acute lung injury.

PubMed

Peters, Dorothea M; Vadász, István; Wujak, Lukasz; Wygrecka, Malgorzata; Olschewski, Andrea; Becker, Christin; Herold, Susanne; Papp, Rita; Mayer, Konstantin; Rummel, Sebastian; Brandes, Ralph P; Günther, Andreas; Waldegger, Siegfried; Eickelberg, Oliver; Seeger, Werner; Morty, Rory E

2014-01-21

TGF-β is a pathogenic factor in patients with acute respiratory distress syndrome (ARDS), a condition characterized by alveolar edema. A unique TGF-β pathway is described, which rapidly promoted internalization of the αβγ epithelial sodium channel (ENaC) complex from the alveolar epithelial cell surface, leading to persistence of pulmonary edema. TGF-β applied to the alveolar airspaces of live rabbits or isolated rabbit lungs blocked sodium transport and caused fluid retention, which--together with patch-clamp and flow cytometry studies--identified ENaC as the target of TGF-β. TGF-β rapidly and sequentially activated phospholipase D1, phosphatidylinositol-4-phosphate 5-kinase 1α, and NADPH oxidase 4 (NOX4) to produce reactive oxygen species, driving internalization of βENaC, the subunit responsible for cell-surface stability of the αβγENaC complex. ENaC internalization was dependent on oxidation of βENaC Cys(43). Treatment of alveolar epithelial cells with bronchoalveolar lavage fluids from ARDS patients drove βENaC internalization, which was inhibited by a TGF-β neutralizing antibody and a Tgfbr1 inhibitor. Pharmacological inhibition of TGF-β signaling in vivo in mice, and genetic ablation of the nox4 gene in mice, protected against perturbed lung fluid balance in a bleomycin model of lung injury, highlighting a role for both proximal and distal components of this unique ENaC regulatory pathway in lung fluid balance. These data describe a unique TGF-β-dependent mechanism that regulates ion and fluid transport in the lung, which is not only relevant to the pathological mechanisms of ARDS, but might also represent a physiological means of acutely regulating ENaC activity in the lung and other organs.

Management of diarrhea in a DTU.

PubMed

Kamala, C S; Vishwanathakumar, H M; Shetti, P M; Anand, N

1996-10-01

A retrospective review of cases seen in the Diarrhea Treatment and Training Unit (DTU) of Bangalore (India) Medical College's Vani Vilas Children's Hospital during 1992-1994 confirmed the efficacy of the standard case management approach. This strategy entails oral rehydration therapy (ORT), continued feeding, and selective use of intravenous fluids and antibiotics. Of the 7966 children (4374 males and 3592 females) reporting to the DTU during the 2-year study period, only 2412 (30.5%) had received oral rehydration solution (ORS) or home-available fluids before admission. Acute watery diarrhea was present in 7316 cases (91.84%). Death occurred in 59 acute watery diarrhea cases, 6 dysentery cases, and 7 persistent diarrhea cases. The average time for cases managed in the ORT area was 2 hours and 45 minutes, while the hospital stay for admitted cases averaged 3 days. In 6957 cases (87.33%), ORS was sufficient treatment. Of the 1009 children (12.67%) who required intravenous fluids, 254 had dehydration attributable to conditions such as persistent vomiting and inability to drink due to oral thrush. Only the 512 children (6.2%) with cholera and dysentery received antibiotics. Of the 72 children who died (case fatality rate, 0.9%), 43 had associated severe malnutrition with pneumonia and anemia, 14 had a central nervous system infection, and 13 had septicemia; in only 2 cases could death be directly ascribed to diarrheal disease. One of these cases was due to shigella encephalopathy and the other to severe dehydration with acidosis. The average cost of treatment per patient was Rs 2.91 when only ORS was used compared with Rs 24.28 when intravenous rehydration was required. The finding that less than one-third of children had received ORS before admission suggests a need for the establishment of more DTUs in large hospitals that can train community-based health personnel in diarrhea case management.

Significance of the interleukin-1 receptor antagonist/interleukin-1 beta ratio as a prognostic factor in patients with pulmonary sarcoidosis.

PubMed

Mikuniya, T; Nagai, S; Takeuchi, M; Mio, T; Hoshino, Y; Miki, H; Shigematsu, M; Hamada, K; Izumi, T

2000-01-01

Various factors such as serum angiotensin-converting enzyme (sACE) activity, bronchoalveolar lavage (BAL) fluid lymphocyte percent, CD4/CD8 ratio, and shadows on chest radiograph have been identified as indexes of disease activity in patients with sarcoidosis. However, it remains to be confirmed whether these factors can predict clinical outcomes. To examine whether the interleukin-1 receptor antagonist (IL-1ra)/IL-1 beta ratio can predict the clinical course, we prospectively followed the clinical courses of 30 patients with pulmonary sarcoidosis 4 years after measurement of immunoreactive amounts of IL-1ra or IL-1 beta in the culture supernatants obtained from BAL fluid macrophages. Immunoreactive amounts of IL-1ra or IL-1 beta were measured using ELISA. Changes in pulmonary function, sACE activity, and shadows on chest radiographs during observation periods were evaluated as markers of changes in disease activity. We found that the patients whose shadows on chest radiographs showed improvement had a higher molar IL-1ra/IL-1 beta ratio than the patients whose shadows persistently remained 4 years after BAL examination (p < 0.05). The molar ratio was found to be positively correlated with improvement of percent vital capacity (p < 0.05) and negatively correlated with the ratio of sACE activity at the time of the last observation to sACE activity at the time of BAL (sACE(LAST)/sACE(BAL), p < 0.01). The sACE(LAST)/sACE(BAL) ratio was significantly lower in patients whose shadows on chest radiographs decreased than in those whose shadows remained unchanged (p < 0.005). The IL-1ra/IL-1 beta ratio in the BAL fluid macrophage culture supernatants in patients with pulmonary sarcoidosis could be a useful marker in predicting the persistence of granulomatous lesions (chronicity). Copyright 2000 S. Karger AG, Basel

Refractory Hypertension Is not Attributable to Intravascular Fluid Retention as Determined by Intracardiac Volumes.

PubMed

Velasco, Alejandro; Siddiqui, Mohammed; Kreps, Eric; Kolakalapudi, Pavani; Dudenbostel, Tanja; Arora, Garima; Judd, Eric K; Prabhu, Sumanth D; Lloyd, Steven G; Oparil, Suzanne; Calhoun, David A

2018-06-04

Refractory hypertension (RfHTN) is an extreme phenotype of antihypertensive treatment failure defined as lack of blood pressure control with ≥5 medications, including a long-acting thiazide and a mineralocorticoid receptor antagonist. RfHTN is a subgroup of resistant hypertension (RHTN), which is defined as blood pressure >135/85 mm Hg with ≥3 antihypertensive medications, including a diuretic. RHTN is generally attributed to persistent intravascular fluid retention. It is unknown whether alternative mechanisms are operative in RfHTN. Our objective was to determine whether RfHTN is characterized by persistent fluid retention, indexed by greater intracardiac volumes determined by cardiac magnetic resonance when compared with controlled RHTN patients. Consecutive patients evaluated in our institution with RfHTN and controlled RHTN were prospectively enrolled. Exclusion criteria included advanced chronic kidney disease and masked or white coat hypertension. All enrolled patients underwent biochemical testing and cardiac magnetic resonance. The RfHTN group (n=24) was younger (mean age, 51.7±8.9 versus 60.6±11.5 years; P =0.003) and had a greater proportion of women (75.0% versus 43%; P =0.02) compared with the controlled RHTN group (n=30). RfHTN patients had a greater left ventricular mass index (88.3±35.0 versus 54.6±12.5 g/m 2 ; P <0.001), posterior wall thickness (10.1±3.1 versus 7.7±1.5 mm; P =0.001), and septal wall thickness (14.5±3.8 versus 10.0±2.2 mm; P <0.001). There was no difference in B-type natriuretic peptide levels and left atrial or ventricular volumes. Diastolic dysfunction was noted in RfHTN. Our findings demonstrate greater left ventricular hypertrophy without chamber enlargement in RfHTN, suggesting that antihypertensive treatment failure is not attributable to intravascular volume retention. © 2018 American Heart Association, Inc.

Low levels of HIV-1 RNA detected in the cerebrospinal fluid after up to 10 years of suppressive therapy are associated with local immune activation

PubMed Central

Dahl, Viktor; Peterson, Julia; Fuchs, Dietmar; Gisslen, Magnus; Palmer, Sarah; Price, Richard W.

2015-01-01

Objective and design Though combination antiretroviral therapy reduces the concentration of HIV-1 RNA in both plasma and cerebrospinal fluid (CSF) below the detection limit of clinical assays, low levels of HIV-1 RNA are frequently detectable in plasma using more sensitive assays. We examined the frequency and magnitude of persistent low-level HIV-1 RNA in CSF and its relation to the central nervous system (CNS) immune activation. Methods CSF and plasma HIV-1 RNA were measured using the single-copy assay with a detection limit of 0.3 copies/ml in 70 CSF and 68 plasma samples from 45 treated HIV-1-infected patients with less than 40 copies/ml of HIV-1 RNA in both fluids by standard clinical assays. We also measured CSF neopterin to assess intrathecal immune activation. Theoretical drug exposure was estimated using the CNS penetration-efficacy score of treatment regimens. Results CSF HIV-1 RNA was detected in 12 of the 70 CSF samples (17%) taken after up to 10 years of suppressive therapy, compared to 39 of the 68 plasma samples (57%) with a median concentration of less than 0.3 copies/ml in CSF compared to 0.3 copies/ml in plasma (P <0.0001). CSF samples with detectable HIV-1 RNA had higher CSF neopterin levels (mean 8.2 compared to 5.7 nmol/l; P =0.0085). Patients with detectable HIV-1 RNA in CSF did not differ in pretreatment plasma HIV-1 RNA levels, nadir CD4+ cell count or CNS penetration-efficacy score. Conclusion Low-level CSF HIV-1 RNA and its association with elevated CSF neopterin highlight the potential for the CNS to serve as a viral reservoir and for persistent infection to cause subclinical CNS injury. PMID:25022595

High-resolution Fourier-Domain Optical Coherence Tomography and Microperimetric Findings After Macula-off Retinal Detachment Repair

PubMed Central

Smith, Allison J.; Telander, David G.; Zawadzki, Robert J.; Choi, Stacey S.; Morse, Lawrence S.; Werner, John S.; Park, Susanna S.

2009-01-01

Objective To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1). Design Prospective observational case series. Participants Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy. Methods FD OCT with axial and transverse resolution of 4.5 μm and 10 to 15 μm, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function. Main Outcome Measures Stratus OCT scans, FD OCT scans, and MP-1 data. Results Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (P<0.001, χ2). Both imaging modalities revealed persistent subretinal fluid in 2 eyes (12%) and lamellar hole in 1 eye. Among 7 subjects who had reliable MP-1 data, areas of abnormal function corresponded to areas of photoreceptor layer disruptions or persistent subretinal fluid in 5 subjects (71%); one subject had normal FD OCT and MP-1. Conclusions Photoreceptor disruption after macula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair. PMID:18672289

Low levels of HIV-1 RNA detected in the cerebrospinal fluid after up to 10 years of suppressive therapy are associated with local immune activation.

PubMed

Dahl, Viktor; Peterson, Julia; Fuchs, Dietmar; Gisslen, Magnus; Palmer, Sarah; Price, Richard W

2014-09-24

Though combination antiretroviral therapy reduces the concentration of HIV-1 RNA in both plasma and cerebrospinal fluid (CSF) below the detection limit of clinical assays, low levels of HIV-1 RNA are frequently detectable in plasma using more sensitive assays. We examined the frequency and magnitude of persistent low-level HIV-1 RNA in CSF and its relation to the central nervous system (CNS) immune activation. CSF and plasma HIV-1 RNA were measured using the single-copy assay with a detection limit of 0.3 copies/ml in 70 CSF and 68 plasma samples from 45 treated HIV-1-infected patients with less than 40 copies/ml of HIV-1 RNA in both fluids by standard clinical assays. We also measured CSF neopterin to assess intrathecal immune activation. Theoretical drug exposure was estimated using the CNS penetration-efficacy score of treatment regimens. CSF HIV-1 RNA was detected in 12 of the 70 CSF samples (17%) taken after up to 10 years of suppressive therapy, compared to 39 of the 68 plasma samples (57%) with a median concentration of less than 0.3 copies/ml in CSF compared to 0.3 copies/ml in plasma (P < 0.0001). CSF samples with detectable HIV-1 RNA had higher CSF neopterin levels (mean 8.2 compared to 5.7 nmol/l; P = 0.0085). Patients with detectable HIV-1 RNA in CSF did not differ in pretreatment plasma HIV-1 RNA levels, nadir CD4 cell count or CNS penetration-efficacy score. Low-level CSF HIV-1 RNA and its association with elevated CSF neopterin highlight the potential for the CNS to serve as a viral reservoir and for persistent infection to cause subclinical CNS injury.

Risk factors for bronchiectasis in children with cystic fibrosis.

PubMed

Sly, Peter D; Gangell, Catherine L; Chen, Linping; Ware, Robert S; Ranganathan, Sarath; Mott, Lauren S; Murray, Conor P; Stick, Stephen M

2013-05-23

Bronchiectasis develops early in the course of cystic fibrosis, being detectable in infants as young as 10 weeks of age, and is persistent and progressive. We sought to determine risk factors for the onset of bronchiectasis, using data collected by the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) intensive surveillance program. We examined data from 127 consecutive infants who received a diagnosis of cystic fibrosis after newborn screening. Chest computed tomography (CT) and bronchoalveolar lavage (BAL) were performed, while the children were in stable clinical condition, at 3 months and 1, 2, and 3 years of age. Longitudinal data were used to determine risk factors associated with the detection of bronchiectasis from 3 months to 3 years of age. The point prevalence of bronchiectasis at each visit increased from 29.3% at 3 months of age to 61.5% at 3 years of age. In multivariate analyses, risk factors for bronchiectasis were presentation with meconium ileus (odds ratio, 3.17; 95% confidence interval [CI], 1.51 to 6.66; P=0.002), respiratory symptoms at the time of CT and BAL (odds ratio, 2.27; 95% CI, 1.24 to 4.14; P=0.008), free neutrophil elastase activity in BAL fluid (odds ratio, 3.02; 95% CI, 1.70 to 5.35; P<0.001), and gas trapping on expiratory CT (odds ratio, 2.05; 95% CI, 1.17 to 3.59; P=0.01). Free neutrophil elastase activity in BAL fluid at 3 months of age was associated with persistent bronchiectasis (present on two or more sequential scans), with the odds seven times as high at 12 months of age and four times as high at 3 years of age. Neutrophil elastase activity in BAL fluid in early life was associated with early bronchiectasis in children with cystic fibrosis. (Funded by the National Health and Medical Research Council of Australia and Cystic Fibrosis Foundation Therapeutics.)

[The cornea: stasis and dynamics].

PubMed

Nishida, Teruo

2008-03-01

The physiological roles of the cornea are to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Good vision thus requires maintenance of the transparency and proper refractive shape of the cornea. Although the cornea appears to be a relatively static structure, dynamic processes operate within and around the cornea at the tissue, cell, and molecular level. In this article, I review the mechanisms responsible for maintenance of corneal homeostasis as well as the development of new modes of treatment for various corneal diseases. I. The static cornea: structure and physiological functions. The cornea is derived from ectoderm, so that it can be considered as transparent skin. It is devoid of blood vessels and manifests the highest sensitivity in the entire body. The surface of the cornea is covered by tear fluid, which serves both as a lubricant and as a conduit for regulatory molecules. The cornea is also supplied with oxygen and various nutrients by the aqueous humor and a loop vascular system in addition to tear fluid. The cornea interacts with its surrounding tissues directly as well as indirectly through tear fluid or aqueous humor, with such interactions playing an important role in the regulation of corneal structure and functions. The resident cells of the cornea-epithelial cells, fibroblasts (keratocytes), and endothelial cells--also engage in mutual interactions through network systems. These interactions as well as those with infiltrated cells and regulation by nerves contribute to the maintenance of the normal structure and functions of the cornea as well as to the repair of corneal injuries. II. The dynamic cornea: maintenance of structure and functions by network systems. Developments in laser and computer technology have allowed observation of the cells and collagen fibers within the cornea. Furthermore, progress in cell and molecular biology has allowed characterization of dynamic network systems-including cell-cell and cell-extracellular matrix interactions as well as cytokines and neural factors-that contribute to the maintenance of corneal transparency and shape. III. Disruption of network systems: persistent corneal epithelial defects and corneal ulcer. Selection of the appropriate treatment for pathologic lesions of the cornea and the accompanying decrease in visual acuity requires localization of the lesion with regard to the epithelium, stroma, or endothelium of the cornea. In certain instances, however, it is not possible to determine the cause of the problem within the cornea. In such cases, the cause of the pathologic lesion and the target for treatment may lie in the surrounding tissues or environment. For example, corneal epithelial wound healing may be delayed, leading to the development of persistent epithelial defects, as a result of disruption of intercellular junctions between epithelial cells, an abnormality of the corneal basement membrane, altered concentrations of various cytokines in tear fluid, a lowered corneal sensation, or allergic reactions in the lid conjunctiva. Loss of corneal epithelial barrier function can further allow inflammatory cytokines present in tear fluid, together with infiltrated cells, to activate keratocytes and elicit excessive degradation of collagen in the stroma, thereby giving rise to corneal ulcer. IV. Development of new drugs for corneal diseases. We have attempted to apply the results of basic scientific research to the development of new drugs for corneal diseases that remain difficult to treat. The process of authorization for new drugs from the Ministry of Health, Labor, and Welfare takes more than two decades, however. The path from the bench to clinical practice is thus a long one. 1. Development of eyedrops for treatment of persistent corneal epithelial defects. We demonstrated the clinical efficacy of fibronectin eyedrops for the treatment of persistent epithelial defects of the cornea. However, the possibility of blood-borne infections has interfered with the development of serum-derived fibronectin as a drug. An automated machine for the preparation of autologous fibronectin eyedrops has therefore recently been developed. Furthermore, in seeking an alternative to fibronectin eyedrops, we are investigating the effects of a peptide corresponding to the second cell-binding domain of fibronectin on corneal epithelial wound healing. Considering that urokinase-type plasminogen activator may be expressed at the site of corneal epithelial defects and facilitates epithelial migration, the potential clinical application of annexin V, which stimulates the secretion of urokinase-type plasminogen activator for the treatment of persistent corneal epithelial defects is also now under investigation in Japan. 2. Development of eyedrops for treatment of neurotrophic keratopathy. Substance P, a neurotransmitter, stimulates corneal epithelial migration in a synergistic manner with insulin-like growth factor (IGF)--1. We have shown that eyedrops containing both the substance P-derived peptide FGLM-amide and the IGF-1--derived peptide SSSR are effective for the treatment of persistent corneal epithelial defects in individuals with diabetic keratopathy or neurotrophic keratopathy, both of which are associated with a reduction in corneal sensation. 3. Development of drugs for corneal ulcer. Treatment of corneal infection with antibiotics does not necessarily halt the process of corneal ulceration, which is characterized by excessive degradation of stromal collagen, or resolve persistent corneal epithelial defects. In addition to eyedrops for the treatment of persistent corneal epithelial defects, we have therefore also been working on the development of new drugs for the treatment of corneal ulcer. To this end, we have established an experimental system in which corneal fibroblasts are cultured in a three-dimensional collagen gel. With this system, we have shown that triptolide and steroids inhibit collagen degradation by corneal fibroblasts. Triptolide or its derivatives are thus potential drugs for the treatment of corneal ulcer and would work by acting directly on corneal fibroblasts rather than by inhibiting the secreted enzymes(matrix metalloproteinases) responsible for collagen degradation.

Shear flow of one-component polarizable fluid in a strong electric field

NASA Astrophysics Data System (ADS)

Sun, J. M.; Tao, R.

1996-04-01

A shear flow of one-component polarizable fluid in a strong electric field has a structural transition at a critical shear stress. When the shear stress is increased from zero up to the critical shear stress, the flow (in the x direction) has a flowing-chain (FC) structure, consisting of tilted or broken chains along the field (z direction). At the critical shear stress, the FC structure gives way to a flowing-hexagonal-layered (FHL) structure, consisting of several two-dimensional layers which are parallel to the x-z plane. Within one layer, particles form strings in the flow direction. Strings are constantly sliding over particles in strings right beneath. The effective viscosity drops dramatically at the structural change. As the shear stress reduces, the FHL structure persists even under a stress-free state if the thermal fluctuation is very weak. This structure change in the charging and discharging process produces a large hysteresis.

A mechanism for pressure anisotropy and mirror instability in the dayside magnetosheath

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crooker, N.U.; Siscoe, G.L.

1977-01-01

The plasma in the dayside magnetosheaht exhibits a persistent pressure anisotropy in the sense p/sub perpendicular/>p/sub parallel/. A likely source for this anisotropy is the effect of field compression and plasma depletion along field lines as magnetosheath plasma flows toward the magnetopause. The model of Zwan and Wolf describing this effect for the case of isotropic pressure is combined with the double-adiabatic fluid equations to predict the behavior of the anisotropic pressure. For a fluid element following a streamline inward from the bow shock, we find theoretical pressure anisotropies of magnitude large enough to trigger the mirror instability over mostmore » of the dayside magnetosheath. These findings are supported by the observations of Kaufmann et al. of large-amplitude hydromagnetic waves in the inner magnetosheath believed to be generated by the mirror instability. (AIP)« less

Extracorporeal Ultrafiltration for Fluid Overload in Heart Failure

PubMed Central

Costanzo, Maria Rosa; Ronco, Claudio; Abraham, William T.; Agostoni, Piergiuseppe; Barasch, Jonathan; Fonarow, Gregg C.; Gottlieb, Stephen S.; Jaski, Brian E.; Kazory, Amir; Levin, Allison P.; Levin, Howard R.; Marenzi, Giancarlo; Mullens, Wilfried; Negoianu, Dan; Redfield, Margaret M.; Tang, W.H. Wilson; Testani, Jeffrey M.; Voors, Adriaan A.

2017-01-01

More than 1 million heart failure hospitalizations occur annually, and congestion is the predominant cause. Rehospitalizations for recurrent congestion portend poor outcomes independently of age and renal function. Persistent congestion trumps serum creatinine increases in predicting adverse heart failure outcomes. No decongestive pharmacological therapy has reduced these harmful consequences. Simplified ultrafiltration devices permit fluid removal in lower-acuity hospital settings, but with conflicting results regarding safety and efficacy. Ultrafiltration performed at fixed rates after onset of therapy-induced increased serum creatinine was not superior to standard care and resulted in more complications. In contrast, compared with diuretic agents, some data suggest that adjustment of ultrafiltration rates to patients’ vital signs and renal function may be associated with more effective decongestion and fewer heart failure events. Essential aspects of ultrafiltration remain poorly defined. Further research is urgently needed, given the burden of congestion and data suggesting sustained benefits of early and adjustable ultrafiltration. PMID:28494980

Eosinophilic Pleural Effusion: A Rare Manifestation of Hypereosinophilic Syndrome

PubMed Central

Okafor, Ndubuisi C.; Oso, Ayodeji A.; Oranu, Amanke C.; Wolff, Steven M.; Murray, John J.

2009-01-01

Several causes of eosinophilic pleural effusions have been described with malignancy being the commonest cause. Hypereosinophilic syndrome (HES) is a rare disease and very few cases have been reported of HES presenting as eosinophilic pleural effusion (EPE). We report a case of a 26-year-old male who presented with shortness of breath. He had bilateral pleural effusions, generalized lymphadenopathy, splenomegaly, and leukocytosis with marked peripheral blood eosinophilia. The pleural fluid was exudative, with 25%–30% eosinophilis, and absence of neoplastic cells. Hypereosinophilic syndrome was diagnosed after other causes of eosinophilia were excluded. He continued to be dyspneic with persistent accumulation of eosinophilic pleural fluid, even after his peripheral eosinophil count had normalized in response to treatment. This patient represents a very unusual presentation of HES with dyspnea and pleural effusions and demonstrates that treatment based on response of peripheral eosinophil counts, as is currently recommended, may not always be clinically adequate. PMID:20111739

Eosinophilic pleural effusion: a rare manifestation of hypereosinophilic syndrome.

PubMed

Okafor, Ndubuisi C; Oso, Ayodeji A; Oranu, Amanke C; Wolff, Steven M; Murray, John J

2009-01-01

Several causes of eosinophilic pleural effusions have been described with malignancy being the commonest cause. Hypereosinophilic syndrome (HES) is a rare disease and very few cases have been reported of HES presenting as eosinophilic pleural effusion (EPE). We report a case of a 26-year-old male who presented with shortness of breath. He had bilateral pleural effusions, generalized lymphadenopathy, splenomegaly, and leukocytosis with marked peripheral blood eosinophilia. The pleural fluid was exudative, with 25%-30% eosinophilis, and absence of neoplastic cells. Hypereosinophilic syndrome was diagnosed after other causes of eosinophilia were excluded. He continued to be dyspneic with persistent accumulation of eosinophilic pleural fluid, even after his peripheral eosinophil count had normalized in response to treatment. This patient represents a very unusual presentation of HES with dyspnea and pleural effusions and demonstrates that treatment based on response of peripheral eosinophil counts, as is currently recommended, may not always be clinically adequate.

Repair of Spontaneous Cerebrospinal Fluid Otorrhea from Defect of Middle Cranial Fossa

PubMed Central

Goh, Young Bum; Han, Chi-Sung

2013-01-01

Spontaneous cerebrospinal fluid (CSF) otorrhea is defined as CSF otorrhea where there are no identifiable causes including previous trauma, surgery, infection, neoplasm or congenital anomaly. The condition is rare. The origin of CSF leak is commonly a defect in the tegmen of the middle cranial fossa. The pathophysiology of spontaneous CSF otorrhea is unclear. Two theories of the etiology of bony defects of the temporal bone are the congenital bony defect theory and arachnoid granulation theory. The authors experienced a case of a 49-year-old female patient admitted with the complaint of persistent right ear fullness. Computed tomography revealed a large defect of the middle fossa and suspicious CSF otorrhea through the defect of tegmen tympani. Repair was successful with multiple bone chips using the transmastoid approach. The postoperative course was good and there has been no recurrence of the CSF leakage. PMID:24653924

Measuring gravity currents in the Chicago River, Chicago, Illinois

USGS Publications Warehouse

Oberg, K.A.; Czuba, J.A.; Johnson, K.K.

2008-01-01

Recent studies of the Chicago River have determined that gravity currents are responsible for persistent bidirectional flows that have been observed in the river. A gravity current is the flow of one fluid within another caused by a density difference between the fluids. These studies demonstrated how acoustic Doppler current profilers (ADCP) can be used to detect and characterize gravity currents in the field. In order to better understand the formation and evolution of these gravity currents, the U.S. Geological Survey (USGS) has installed ADCPs and other instruments to continuously measure gravity currents in the Chicago River and the North Branch Chicago River. These instruments include stage sensors, thermistor strings, and both upward-looking and horizontal ADCPs. Data loggers and computers installed at gaging stations along the river are used to collect data from these instruments and transmit them to USGS offices. ?? 2008 IEEE.

Transient monoplegia and paraesthesia after an epidural blood patch for a spinal cerebrospinal fluid leak.

PubMed

Cheung, Alvin Ho-Kwan; Li, Lai-Fung; So, Vincent Ching; Leung, May Ka-Mei; Lui, Wai-Man

2015-09-01

We describe the very rare complication of new onset complete paralysis and numbness of one limb after an epidural blood patch in a 36-year-old woman. Intracranial hypotension resulting from a spinal cerebrospinal fluid fistula may be treated by epidural injection of autologous blood that is, a blood patch. This is usually a safe and effective procedure. The woman's muscle strength of hip flexion, extension, ankle dorsiflexion and plantarflexion decreased from 5/5 to 0/5 following the procedure. After symptom onset, an MRI of her spine showed no compressive or ischaemic lesions amenable to urgent intervention. The cause of neurological deficit was at that time unknown and steroids were administered. Her symptoms persisted for about 2 days and gradually improved. In this paper, the management plan and the course of this rare and alarming complication is reported. Copyright © 2015. Published by Elsevier Ltd.

Flow Structures within a Helicopter Rotor Hub Wake

NASA Astrophysics Data System (ADS)

Elbing, Brian; Reich, David; Schmitz, Sven

2015-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The measurement suite included total hub drag and wake velocity measurements (LDV, PIV, stereo-PIV) at three downstream locations. The main objective was to understand the spatiotemporal evolution of the unsteady wake between the rotor hub and the nominal location of the empennage (tail). Initial analysis of the data revealed prominent two- and four-per-revolution fluid structures linked to geometric hub features persisting into the wake far-field. In addition, a six-per-revolution fluid structure was observed in the far-field, which is unexpected due to the lack of any hub feature with the corresponding symmetry. This suggests a nonlinear interaction is occurring within the wake to generate these structures. This presentation will provide an overview of the experimental data and analysis with particular emphasis on these six-per-revolution structures.

LES of Laminar-to-Turbulent Particle-Fluid Dynamics in Human and Nonhuman Primate Airways: Applications to Aerosolized Drug Delivery Animal Testing

NASA Astrophysics Data System (ADS)

Geisler, Taylor; Padhy, Sourav; Shaqfeh, Eric; Iaccarino, Gianluca

2016-11-01

Both the human health benefit and risk from the inhalation of aerosolized medications is often predicted by extrapolating experimental data taken using nonhuman primates to human inhalation. In this study, we employ Large Eddy Simulation to simulate particle-fluid dynamics in realistic upper airway models of both humans and rhesus monkeys. We report laminar-to-turbulent flow transitions triggered by constrictions in the upper trachea and the persistence of unsteadiness into the low Reynolds number bifurcating lower airway. Micro-particle deposition fraction and locations are shown to depend significantly on particle size. In particular, particle filtration in the nasal airways is shown to approach unity for large aerosols (8 microns) or high-rate breathing. We validate the accuracy of LES mean flow predictions using MRV imaging results. Additionally, particle deposition fractions are validated against experiments in 3 model airways.

Purification and function of two analgesic and anti-inflammatory peptides from coelomic fluid of the earthworm, Eisenia foetida.

PubMed

Li, Chunlong; Chen, Mengrou; Li, Xiaojie; Yang, Meifeng; Wang, Ying; Yang, Xinwang

2017-03-01

The potential application of anti-inflammatory and analgesic compounds in medication and therapeutic care have become of increasing interest. We purified and characterized two novel analgesic and anti-inflammatory peptides, VQ-5 and AQ-5, from the coelomic fluid of the earthworm (Eisenia foetida). Their primary structures were determined as VSSVQ and AMADQ, respectively. Both peptides, especially AQ-5, exhibited analgesic activity in mouse models of persistent neuropathic pain and inflammation. AQ-5 also inhibited tumor necrosis factor alpha and cyclooxygenase-2 production. The mitogen-activated protein kinase signaling pathway, which is involved in analgesic and anti-inflammatory functions, was inhibited by AQ-5. Thus, the analgesic and anti-inflammatory effects of these peptides, especially AQ-5, demonstrated their potential as candidates for the development of novel analgesic medicines. Copyright © 2017 Elsevier Inc. All rights reserved.

Transmastoid approach to temporal bone cerebrospinal fluid leaks.

PubMed

Oliaei, Sepehr; Mahboubi, Hossein; Djalilian, Hamid R

2012-01-01

The aim of the study was to evaluate various presentations and treatment options for spontaneous cerebrospinal fluid (CSF) leakage originating in the temporal bone. Clinical data and imaging results for 18 ears (15 patients) presenting with spontaneous CSF leakage originating in the temporal bone were reviewed. Average follow-up period was 13.5 months. The main outcome measure was presence of persistent CSF leak postoperatively. A standard postauricular mastoidectomy was performed. Fifteen patients diagnosed with spontaneous CSF leakage over an 8-year period including 3 treated for bilateral disease were included in the study. The age ranged between 33 and 83 years. Presenting symptoms included serous otitis media (44%), persistent otorrhea after tympanostomy tube placement (28%), and meningitis (28%). Preoperative diagnosis was made using imaging studies and was substantiated by observation of CSF leakage and dural herniation intraoperatively. Treatment was eustachian tube plugging (5%), mastoidectomy with fat obliteration (61%), middle fossa approach with extradural (17%), intradural repair (5%), or combined middle fossa and transmastoid (TM) approach (11%). Successful treatment was obtained in 17 of the 18 cases. The last 9 patients in the series underwent TM approach alone for repair with no treatment failures. Repair of defects in tegmen mastoideum and posterior fossa can be successfully achieved on an outpatient basis without regard to size and multitude of defects via TM approach. This approach obviates the need for a craniotomy or lumbar drain. Copyright © 2012 Elsevier Inc. All rights reserved.

Longitudinal Analysis of Cerebrospinal Fluid and Plasma HIV-1 Envelope Sequences Isolated From a Single Donor with HIV Asymptomatic Neurocognitive Impairment.

PubMed

Vázquez-Santiago, Fabián; García, Yashira; Rivera-Román, Ivelisse; Noel, Richard J; Wojna, Valerie; Meléndez, Loyda M; Rivera-Amill, Vanessa

Combined antiretroviral treatment (cART) has changed the clinical presentation of HIV-associated neurocognitive disorders (HAND) to that of the milder forms of the disease. Asymptomatic neurocognitive impairment (ANI) is now more prevalent and is associated with increased morbidity and mortality risk in HIV-1-infected people. HIV-1 envelope ( env ) genetic heterogeneity has been detected within the central nervous system (CNS) of individuals with ANI. Changes within env determine co-receptor use, cellular tropism, and neuropathogenesis. We hypothesize that compartmental changes are associated with HIV-1 env C2V4 during ANI and sought to analyze paired HIV-1 env sequences from plasma and cerebrospinal fluid (CSF) of a female subject undergoing long-term cART. Paired plasma and CSF samples were collected at 12-month intervals and HIV-1 env C2V4 was cloned and sequenced. Phylogenetic analysis of paired samples consistently showed genetic variants unique to the CSF. Phenotypic prediction showed CCR5 (R5) variants for all CSF-derived sequences and showed minor X4 variants (or dual-tropic) in the plasma at later time points. Viral compartmentalization was evident throughout the study, suggesting that the occurrence of distinctive env strains may contribute to the neuropathogenesis of HAND. Our study provides new insights about the genetic characteristics within the C2V4 of HIV-1 env that persist after long-term cART and during the course of persistent ANI.

Aflibercept in refractory wet AMD treated with ranibizumab: Anatomical and visual outcome.

PubMed

Abou-Ltaif, Sleiman

2016-01-01

To assess the anatomical outcome of patients with exudative age-related macular degeneration resistant to ranibizumab treated with aflibercept. Prospective, interventional, case series, where we treated a group of patients deemed resistant to Ranibizumab after 6 months of persistence of intra- or subretinal fluid despite continuous treatment. The study included 17 patients, 3 males and 14 females. The average males age was 85 (range 83-87), and that of females was 79.64 (range 68-88). At the start of the study, the central foveal thickness CFT average was 534.76 μm (range 252-999). At 1 month and after 1 injection of Aflibercept, the CFT average was 324.82 μm (range 222-585). At 4 months and after 3 consecutive injections of Aflibercept the CFT average was 294.76 μm (range 184-640). At 6 months the CFT average was 356 μm (range 206-609). At the 5th visit only 8 out 17 (47%) patients required repeated injection either for persistent fluids or for recurrence. At the 6th and final visit only 4 out of 17 (23.5%) needed repeated injections, of them only one was treated on the visit before and treatment was given as very little response was observed from last injection, and all other 3 were not treated on the visit before. Our results showed that aflibercept was able to dry the macula even in advanced case of wet AMD resistant to Ranibizumab.

The comparative toxicity of operational Air Force hydraulic fluids.

PubMed

Mattie, D R; Hoeflich, T J; Jones, C E; Horton, M L; Whitmire, R E; Godin, C S; Flemming, C D; Andersen, M E

1993-01-01

The subchronic (26 day) oral toxicities of two AF hydraulic fluids (MIL-H-5606 [H5], MIL-H-83282 [H8]), a commercial phosphate ester (PE), and two candidate hydraulic fluids (low temperature version of MIL-H-83282 [LT] and chlorotrifluorethylene oligomers [polyCTFE]) were compared in male F-344 rats. Oral dosing was used in order to quickly compare these fluids to PolyCTFE, the only fluid at the time to have been tested in a 90-day inhalation study. Rats were initially dosed with 1.0 g/kg/day of each fluid. H8 increased alkaline phosphatase (ALKP) while LT produced an anemia and leukocytosis. Exposure to H5 fluid resulted in lymphocytopenia and persistent diuresis. Due to their greater toxicity, resulting in lethality in the first dosing study, only 0.5 g/kg/day of PE and PolyCTFE were administered in the second study. Exposure to PE (0.5 g/kg) resulted in an anemia and decreases in BW (day 10 until day 25), spleen/BW ratio, blood urea nitrogen (BUN), and creatinine (CREAT). PolyCREAT (0.5 g/kg) decreased BW (day 11 to the end of the study) and testicular weight. PolyCTFE (0.5 g/kg) increased relative spleen weights, various clinical chemistry parameters, and triggered a reversible diuresis. PolyCTFE (0.5 g/kg), PE (0.5 g/kg), and H5 produced an increase in absolute and relative liver weights compared to control livers. Peroxisomal beta oxidation, an indicator of peroxisomal proliferation, was significantly increased above control levels in the livers of all rats except the PE (0.5 g/kg) group, where the increase was not significant. Hydrocarbon nephropathy, indicated by increased levels of hyaline droplets in kidney tubules, was severe in H5, mild in H8, LT, and PolyCTFE (0.5 g/kg), and minimal in PE (0.5 g/kg). The MIL-H-83282 fluids (H8 and LT) were the least toxic hydraulic fluids. PolyCTFE and PE were the most toxic, with H5 intermediate.

Flow of variably fluidized granular masses across three-dimensional terrain I. Coulomb mixture theory

USGS Publications Warehouse

Iverson, R.M.; Denlinger, R.P.

2001-01-01

Rock avalanches, debris flows, and related phenomena consist of grain-fluid mixtures that move across three-dimensional terrain. In all these phenomena the same basic forces, govern motion, but differing mixture compositions, initial conditions, and boundary conditions yield varied dynamics and deposits. To predict motion of diverse grain-fluid masses from initiation to deposition, we develop a depth-averaged, threedimensional mathematical model that accounts explicitly for solid- and fluid-phase forces and interactions. Model input consists of initial conditions, path topography, basal and internal friction angles of solid grains, viscosity of pore fluid, mixture density, and a mixture diffusivity that controls pore pressure dissipation. Because these properties are constrained by independent measurements, the model requires little or no calibration and yields readily testable predictions. In the limit of vanishing Coulomb friction due to persistent high fluid pressure the model equations describe motion of viscous floods, and in the limit of vanishing fluid stress they describe one-phase granular avalanches. Analysis of intermediate phenomena such as debris flows and pyroclastic flows requires use of the full mixture equations, which can simulate interaction of high-friction surge fronts with more-fluid debris that follows. Special numerical methods (described in the companion paper) are necessary to solve the full equations, but exact analytical solutions of simplified equations provide critical insight. An analytical solution for translational motion of a Coulomb mixture accelerating from rest and descending a uniform slope demonstrates that steady flow can occur only asymptotically. A solution for the asymptotic limit of steady flow in a rectangular channel explains why shear may be concentrated in narrow marginal bands that border a plug of translating debris. Solutions for static equilibrium of source areas describe conditions of incipient slope instability, and other static solutions show that nonuniform distributions of pore fluid pressure produce bluntly tapered vertical profiles at the margins of deposits. Simplified equations and solutions may apply in additional situations identified by a scaling analysis. Assessment of dimensionless scaling parameters also reveals that miniature laboratory experiments poorly simulate the dynamics of full-scale flows in which fluid effects are significant. Therefore large geophysical flows can exhibit dynamics not evident at laboratory scales.

Flow of variably fluidized granular masses across three-dimensional terrain: 1. Coulomb mixture theory

NASA Astrophysics Data System (ADS)

Iverson, Richard M.; Denlinger, Roger P.

2001-01-01

Rock avalanches, debris flows, and related phenomena consist of grain-fluid mixtures that move across three-dimensional terrain. In all these phenomena the same basic forces govern motion, but differing mixture compositions, initial conditions, and boundary conditions yield varied dynamics and deposits. To predict motion of diverse grain-fluid masses from initiation to deposition, we develop a depth-averaged, three-dimensional mathematical model that accounts explicitly for solid- and fluid-phase forces and interactions. Model input consists of initial conditions, path topography, basal and internal friction angles of solid grains, viscosity of pore fluid, mixture density, and a mixture diffusivity that controls pore pressure dissipation. Because these properties are constrained by independent measurements, the model requires little or no calibration and yields readily testable predictions. In the limit of vanishing Coulomb friction due to persistent high fluid pressure the model equations describe motion of viscous floods, and in the limit of vanishing fluid stress they describe one-phase granular avalanches. Analysis of intermediate phenomena such as debris flows and pyroclastic flows requires use of the full mixture equations, which can simulate interaction of high-friction surge fronts with more-fluid debris that follows. Special numerical methods (described in the companion paper) are necessary to solve the full equations, but exact analytical solutions of simplified equations provide critical insight. An analytical solution for translational motion of a Coulomb mixture accelerating from rest and descending a uniform slope demonstrates that steady flow can occur only asymptotically. A solution for the asymptotic limit of steady flow in a rectangular channel explains why shear may be concentrated in narrow marginal bands that border a plug of translating debris. Solutions for static equilibrium of source areas describe conditions of incipient slope instability, and other static solutions show that nonuniform distributions of pore fluid pressure produce bluntly tapered vertical profiles at the margins of deposits. Simplified equations and solutions may apply in additional situations identified by a scaling analysis. Assessment of dimensionless scaling parameters also reveals that miniature laboratory experiments poorly simulate the dynamics of full-scale flows in which fluid effects are significant. Therefore large geophysical flows can exhibit dynamics not evident at laboratory scales.

Laboratory Investigation of Rheology and Infiltration Process of Non-Newtonian Fluids through Porous Media in a Non-Isothermal Flow Regime for Effective Remediation of Contaminants

NASA Astrophysics Data System (ADS)

Naseer, F.

2017-12-01

Contamination of soil and groundwater by adsorbent (persistent) contaminants have been a major concern. Mine tailings, Acid mine drainage, waste disposal areas, active or abandoned surface and underground mines are some major causes of soil and water contamination. It is need of the hour to develop cost effective and efficient remediation techniques for clean-up of soil and aquifers. The objective of this research is to study a methodology of using non-Newtonian fluids for effective remediation of adsorbent contaminants in porous media under non-isothermal flow regimes. The research comprises of three components. Since, non-Newtonian fluid rheology has not been well studied in cold temperatures, the first component of the objective is to expose a non-Newtonian fluid (Guar gum solution) to different temperatures ranging from 30 °C through -5 °C to understand the change in viscosity, shear strength and contact angle of the fluid. Study of the flow characteristic of non-Newtonian fluids in complex porous media has been limited. Hence, the second component of this study will focus on a comparison of flow characteristics of a Newtonian fluid, non-Newtonian fluid and a combination of both fluids in a glass-tube-bundle setup that will act as a synthetic porous media. The study of flow characteristics will also be done for different thermal regimes ranging from -5 °C to 30 °C. The third component of the research will be to compare the effectiveness Guar gum to remediate a surrogate adsorbed contaminant at a certain temperature from the synthetic porous media. Guar gum is biodegradable and hence it is benign to the environment. Through these experiments, the mobility and behavior of Guar gum under varying temperature ranges will be characterized and its effectiveness in removing contaminants from soils will be understood. The impact of temperature change on the fluid and flow stability in the porous medium will be examined in this research. Guar gum is good suspension fluid and hence, studying the suspension capability below the freezing point would be of great importance. The outcome of this research will provide critical knowledge of cost-effective, environmentally benign and time efficient remediation of contaminated mine sites in Alaska and other cold regions.

Effects of the endoparasitoid Cotesia chilonis (Hymenoptera: Braconidae) parasitism, venom, and calyx fluid on cellular and humoral immunity of its host Chilo suppressalis (Lepidoptera: Crambidae) larvae.

PubMed

Teng, Zi-Wen; Xu, Gang; Gan, Shi-Yu; Chen, Xuan; Fang, Qi; Ye, Gong-Yin

2016-02-01

The larval endoparasitoid Cotesia chilonis injects venom and bracoviruses into its host Chilo suppressalis during oviposition. Here we study the effects of the polydnavirus (PDV)-carrying endoparasitoid C. chilonis (Hymenoptera: Braconidae) parasitism, venom and calyx fluid on host cellular and humoral immunity, specifically hemocyte composition, cellular spreading, encapsulation and melanization. Total hemocyte counts (THCs) were higher in parasitized larvae than in unparasitized larvae in the late stages following parasitization. While both plasmatocyte and granulocyte fractions and hemocyte mortality did not differ between parasitized and unparasitized hosts, in vitro spreading behavior of hemocytes was inhibited significantly by parasitism throughout the course of parasitoid development. C. chilonis parasitism suppressed the encapsulation response and melanization in the early stages. Venom alone did not alter cellular immune responses, including effects on THCs, mortality, hemocyte composition, cell spreading and encapsulation, but venom did inhibit humoral immunity by reducing melanization within 6h after injection. In contrast to venom, calyx fluid had a significant effect on cell spreading, encapsulation and melanization from 6h after injection. Dose-response injection studies indicated the effects of venom and calyx fluid synergized, showing a stronger and more persistent reduction in immune system responses than the effect of either injected alone. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Review of electric discharge microplasmas generated in highly fluctuating fluids: Characteristics and application to nanomaterials synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stauss, Sven, E-mail: sven.stauss@plasma.k.u-tokyo.ac.jp; Terashima, Kazuo, E-mail: kazuo@plasma.k.u-tokyo.ac.jp; Muneoka, Hitoshi

2015-05-15

Plasma-based fabrication of novel nanomaterials and nanostructures is indispensible for the development of next-generation electronic devices and for green energy applications. In particular, controlling the interactions between plasmas and materials interfaces, and the plasma fluctuations, is crucial for further development of plasma-based processes and bottom-up growth of nanomaterials. Electric discharge microplasmas generated in supercritical fluids represent a special class of high-pressure plasmas, where fluctuations on the molecular scale influence the discharge properties and the possible bottom-up growth of nanomaterials. This review discusses an anomaly observed for direct current microplasmas generated near the critical point, a local decrease in the breakdownmore » voltage. This anomalous behavior is suggested to be caused by the concomitant decrease of the ionization potential due to the formation of clusters near the critical point, and the formation of extended electron mean free paths caused by the high-density fluctuation near the critical point. It is also shown that in the case of dielectric barrier microdischarges generated close to the critical point, the high-density fluctuation of the supercritical fluid persists. The final part of the review discusses the application of discharges generated in supercritical fluids to synthesis of nanomaterials, in particular, molecular diamond—so-called diamondoids—by microplasmas generated inside conventional batch-type and continuous flow microreactors.« less

Ringin' the water bell: dynamic modes of curved fluid sheets

NASA Astrophysics Data System (ADS)

Kolinski, John; Aharoni, Hillel; Fineberg, Jay; Sharon, Eran

2015-11-01

A water bell is formed by fluid flowing in a thin, coherent sheet in the shape of a bell. Experimentally, a water bell is created via the impact of a cylindrical jet on a flat surface. Its shape is set by the splash angle (the separation angle) of the resulting cylindrically symmetric water sheet. The separation angle is altered by adjusting the height of a lip surrounding the impact point, as in a water sprinkler. We drive the lip's height sinusoidally, altering the separation angle, and ringin' the water bell. This forcing generates disturbances on the steady-state water bell that propagate forward and backward in the fluid's reference frame at well-defined velocities, and interact, resulting in the emergence of an interference pattern unique to each steady-state geometry. We analytically model these dynamics by linearizing the amplitude of the bell's response about the underlying curved geometry. This simple model predicts the nodal structure over a wide range of steady-state water bell configurations and driving frequencies. Due to the curved water bell geometry, the nodal structure is quite complex; nevertheless, the predicted nodal structure agrees extremely well with the experimental data. When we drive the bell beyond perturbative separation angles, the nodal locations surprisingly persist, despite the strikingly altered underlying water bell shape. At extreme driving amplitudes the water sheet assumes a rich variety of tortuous, non-convex shapes; nevertheless, the fluid sheet remains intact.

Differences in the Comparative Stability of Ebola Virus Makona-C05 and Yambuku-Mayinga in Blood

PubMed Central

Schuit, Michael; Miller, David M.; Reddick-Elick, Mary S.; Wlazlowski, Carly B.; Filone, Claire Marie; Herzog, Artemas; Colf, Leremy A.; Wahl-Jensen, Victoria; Hevey, Michael; Noah, James W.

2016-01-01

In support of the response to the 2013–2016 Ebola virus disease (EVD) outbreak in Western Africa, we investigated the persistence of Ebola virus/H.sapiens-tc/GIN/2014/Makona-C05 (EBOV/Mak-C05) on non-porous surfaces that are representative of hospitals, airplanes, and personal protective equipment. We performed persistence studies in three clinically-relevant human fluid matrices (blood, simulated vomit, and feces), and at environments representative of in-flight airline passenger cabins, environmentally-controlled hospital rooms, and open-air Ebola treatment centers in Western Africa. We also compared the surface stability of EBOV/Mak-C05 to that of the prototype Ebola virus/H.sapiens-tc/COD/1976/Yambuku-Mayinga (EBOV/Yam-May), in a subset of these conditions. We show that on inert, non-porous surfaces, EBOV decay rates are matrix- and environment-dependent. Among the clinically-relevant matrices tested, EBOV persisted longest in dried human blood, had limited viability in dried simulated vomit, and did not persist in feces. EBOV/Mak-C05 and EBOV/Yam-May decay rates in dried matrices were not significantly different. However, during the drying process in human blood, EBOV/Yam-May showed significantly greater loss in viability than EBOV/Mak-C05 under environmental conditions relevant to the outbreak region, and to a lesser extent in conditions relevant to an environmentally-controlled hospital room. This factor may contribute to increased communicability of EBOV/Mak-C05 when surfaces contaminated with dried human blood are the vector and may partially explain the magnitude of the most recent outbreak, compared to prior outbreaks. These EBOV persistence data will improve public health efforts by informing risk assessments, structure remediation decisions, and response procedures for future EVD outbreaks. PMID:26849135

Prior to extension, Transcriptomes of fibroblast-like Synoviocytes from extended and Polyarticular juvenile idiopathic arthritis are indistinguishable.

PubMed

Brescia, AnneMarie C; Simonds, Megan M; McCahan, Suzanne M; Sullivan, Kathleen E; Rose, Carlos D

2018-01-08

Our intent was to identify differences between the transcriptome of fibroblast-like synoviocytes (FLS) in oligoarticular juvenile idiopathic arthritis (JIA) before extension when compared to persistent subtype of JIA, when the two are clinically indistinguishable. Additionally, we sought to determine if differences between the transcriptomes of FLS from extended-to-be and polyarticular course JIA could be detected. Our hypothesis was that intrinsic differences in the transcriptome of the FLS from extended-to-be JIA would distinguish them from persistent oligoarticular JIA, before the course is clinically apparent. Global gene expression was defined in cultured FLS from 6 controls, 12 JIA with persistent course, 7 JIA prior to extension (extended-to-be), 4 JIA with extended course and 6 polyarticular onset, using Affymetrix Human GeneChips 133plus2.0. Bioconductor Linear Models for Microarray Analysis revealed 22 probesets with differential expression between persistent and extended-to-be FLS at 15% FDR, however only 2 probesets distinguished extended-to-be from extended and none distinguished extended-to-be and polyarticular at 15% FDR. Differences in extended and polyarticular gene expression profiles were not detected. Confirmation of select genes was done on the RNA level by RT-qPCR and on the protein level in synovial fluid by ELISA. The transcriptome of FLS from extended-to-be juvenile idiopathic arthritis is distinct from persistent course before a clinical distinction can be made. Additionally, the transcriptome of extended-to-be and polyarticular course, including those who have already extended, are indistinguishable. These gene expression data suggest that FLS already reflect a polyarticular behavior early in disease course, suggesting that extended-to-be may be "latent polyarticular" at onset. These differences can be used to develop early biomarkers of disease course, allowing for better-informed treatment decisions.

The Foot-and-Mouth Disease Carrier State Divergence in Cattle

PubMed Central

Eschbaumer, Michael; Rekant, Steven I.; Pacheco, Juan M.; Smoliga, George R.; Hartwig, Ethan J.; Rodriguez, Luis L.

2016-01-01

ABSTRACT The pathogenesis of persistent foot-and-mouth disease virus (FMDV) infection was investigated in 46 cattle that were either naive or had been vaccinated using a recombinant, adenovirus-vectored vaccine 2 weeks before challenge. The prevalence of FMDV persistence was similar in both groups (62% in vaccinated cattle, 67% in nonvaccinated cattle), despite vaccinated cattle having been protected from clinical disease. Analysis of antemortem infection dynamics demonstrated that the subclinical divergence between FMDV carriers and animals that cleared the infection had occurred by 10 days postinfection (dpi) in vaccinated cattle and by 21 dpi in nonvaccinated animals. The anatomic distribution of virus in subclinically infected, vaccinated cattle was restricted to the pharynx throughout both the early and the persistent phases of infection. In nonvaccinated cattle, systemically disseminated virus was cleared from peripheral sites by 10 dpi, while virus selectively persisted within the nasopharynx of a subset of animals. The quantities of viral RNA shed in oropharyngeal fluid during FMDV persistence were similar in vaccinated and nonvaccinated cattle. FMDV structural and nonstructural proteins were localized to follicle-associated epithelium of the dorsal soft palate and dorsal nasopharynx in persistently infected cattle. Host transcriptome analysis of tissue samples processed by laser capture microdissection indicated suppression of antiviral host factors (interferon regulatory factor 7, CXCL10 [gamma interferon-inducible protein 10], gamma interferon, and lambda interferon) in association with persistent FMDV. In contrast, during the transitional phase of infection, the level of expression of IFN-λ mRNA was higher in follicle-associated epithelium of animals that had cleared the infection. This work provides novel insights into the intricate mechanisms of FMDV persistence and contributes to further understanding of this critical aspect of FMDV pathogenesis. IMPORTANCE The existence of a prolonged, asymptomatic carrier state is a political impediment for control and potential eradication of foot-and-mouth disease (FMD). When FMD outbreaks occur, they are often extinguished by massive depopulation of livestock due to the fear that some animals may have undiagnosed subclinical infection, despite uncertainty over the biological relevance of FMD virus (FMDV) persistence. The work described here elucidates aspects of the FMDV carrier state in cattle which may facilitate identification and/or abrogation of asymptomatic FMDV infection. The divergence between animals that clear infection and those that develop persistent infection was demonstrated to occur earlier than previously established. The host antiviral response in tissues maintaining persistent FMDV was downregulated, whereas upregulation of IFN-λ mRNA was found in the epithelium of cattle that had recently cleared the infection. This suggests that the clearing of FMDV infection is associated with an enhanced mucosal antiviral response, whereas FMDV persistence is associated with suppression of the host antiviral response. PMID:27147736

Paleohydrogeology of the San Joaquin basin, California

USGS Publications Warehouse

Wilson, A.M.; Garven, G.; Boles, J.R.

1999-01-01

Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In our numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than ???2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography-to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

Identification of dendritic cells in the blood and synovial fluid of children with Juvenile Idiopathic Arthritis.

PubMed

Tabarkiewicz, Jacek; Postępski, Jacek; Olesińska, Edyta; Roliński, Jacek; Tuszkiewicz-Misztal, Ewa

2011-01-01

Childhood chronic arthritis of unknown etiology is known collectively as juvenile idiopathic arthritis (JIA) and consists of heterogeneous subtypes with unique clinical patterns of disease. JIA is the commonest rheumatic disease in children and may still result in significant disability, with joint deformity, growth impairment, and persistence of active arthritis into adulthood. Basic research is rather focused on rheumatoid arthritis, and this lead to small number of publications considering JIA. In this study we examine, by flow cytometry, the expression of dendritic cells (DCs) in the peripheral blood and synovial fluid of children with active JIA in a group of 220 patients. We reveal a significant decrease in the percentage of immature DCs in the blood of patients compared to control children. Surprisingly, we found higher percentages of mature circulating dendritic cells. Both populations of DCs, immature and mature, were accumulated in patients' synovial fluid. We also confirmed the presence of CD206+/CD209+ in JIA samples, which can represent a population of macrophages with dendritic cells morphology. Our results support the thesis that dendritic cells are crucial in the induction and maintenance of autoimmune response and local inflammation during juvenile idiopathic arthritis.

Ciliary metachronal wave propagation on the compliant surface of Paramecium cells.

PubMed

Narematsu, Naoki; Quek, Raymond; Chiam, Keng-Hwee; Iwadate, Yoshiaki

2015-12-01

Ciliary movements in protozoa exhibit metachronal wave-like coordination, in which a constant phase difference is maintained between adjacent cilia. It is at present generally thought that metachronal waves require hydrodynamic coupling between adjacent cilia and the extracellular fluid. To test this hypothesis, we aspirated a Paramecium cell using a micropipette which completely sealed the surface of the cell such that no fluid could pass through the micropipette. Thus, the anterior and the posterior regions of the cell were hydrodynamically decoupled. Nevertheless, we still observed that metachronal waves continued to propagate from the anterior to the posterior ends of the cell, suggesting that in addition to hydrodynamic coupling, there are other mechanisms that can also transmit the metachronal waves. Such transmission was also observed in computational modeling where the fluid was fully decoupled between two partitions of a beating ciliary array. We also imposed cyclic stretching on the surface of live Paramecium cells and found that metachronal waves persisted in the presence of cyclic stretching. This demonstrated that, in addition to hydrodynamic coupling, a compliant substrate can also play a critical role in mediating the propagation of metachronal waves. © 2015 Wiley Periodicals, Inc.

Kick Detection at the Bit: Early Detection via Low Cost Monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tost, Brian; Rose, Kelly; Aminzadeh, Fred

2016-06-07

Formation fluid influxes (i.e. kicks) pose persistent challenges and operational costs during drilling operations. Implications of kicks range in scale but cumulatively result in substantial costs that affect drilling safety, environment, schedule, and infrastructure. Early kick detection presents a low-cost, easily adopted solution for avoiding well control challenges associated with kicks near the bit. Borehole geophysical tools used during the drilling process as part of the logging-while-drilling (LWD) and measurement-while-drilling (MWD) provide the advantage of offering real-time downhole data. LWD/MWD collect data on both the annulus and borehole wall. The annular data are normally treated as background, and are filteredmore » out to isolate the formation measurements. Because kicks will change the local physical properties of annular fluids, bottom-hole measurements are among the first indicators that a formation fluid has invaded the wellbore. This report describes and validates a technique for using the annular portion of LWD/MWD data to facilitate early kick detection using first order principles. The detection technique leverages data from standard and cost-effective technologies that are typically implemented during well drilling, such as MWD/LWD data in combination with mud-pulse telemetry for data transmission.« less

Analysis of pulsed injection for microgravity receiver tank chilldown

NASA Astrophysics Data System (ADS)

Honkonen, Scott C.; Pietrzyk, Joe R.; Schuster, John R.

The dominant heat transfer mechanism during the hold phase of a tank chilldown cycle in a low-gravity environment is due to fluid motion persistence following the charge. As compared to the single-charge per vent cycle case, pulsed injection maintains fluid motion and the associated high wall heat transfer coefficients during the hold phase. As a result, the pulsed injection procedure appears to be an attractive method for reducing the time and liquid mass required to chill a tank. However, for the representative conditions considered, no significant benefit can be realized by using pulsed injection as compared to the single-charge case. A numerical model of the charge/hold/vent process was used to evaluate the pulsed injection procedure for tank chilldown in microgravity. Pulsed injection results in higher average wall heat transfer coefficients during the hold, as compared to the single-charge case. However, these high levels were not coincident with the maximum wall-to-fluid temperature differences, as in the single-charge case. For representative conditions investigated, the charge/hold/vent process is very efficient. A slightly shorter chilldown time was realized by increasing the number of pulses.

Maternal Azithromycin Therapy for Ureaplasma Intra-Amniotic Infection Delays Preterm Delivery and Reduces Fetal Lung Injury in a Primate Model

PubMed Central

Grigsby, Peta L.; Novy, Miles J.; Sadowsky, Drew W.; Morgan, Terry K.; Long, Mary; Acosta, Ed; Duffy, Lynn B; Waites, Ken B.

2012-01-01

Objective We assessed the efficacy of a maternal multi–dose azithromycin (AZI) regimen, with and without anti–inflammatory agents to delay preterm birth and to mitigate fetal lung injury associated with Ureaplasma parvum intra–amniotic infection (IAI). Study Design Long–term catheterized rhesus monkeys (n=16) received intra–amniotic inoculation of U. parvum (107 CFU/ml, serovar 1). After contraction onset, rhesus monkeys received either no treatment (n=6); AZI (12.5mg/kg, q12h, IV for 10 days; n=5); or AZI plus dexamethasone (DEX) and indomethacin (INDO; n=5). Outcomes included amniotic fluid pro–inflammatory mediators, U. parvum cultures & PCR, AZI pharmacokinetics and the extent of fetal lung inflammation. Results Maternal AZI therapy eradicated U. parvum IAI from the amniotic fluid within 4 days. Placenta and fetal tissues were 90% culture negative at delivery. AZI therapy significantly delayed preterm delivery and prevented advanced fetal lung injury, although residual acute chorioamnionitis persisted. Conclusions Specific maternal antibiotic therapy can eradicate U. parvum from the amniotic fluid and key fetal organs, with subsequent prolongation of pregnancy which provides a therapeutic window of opportunity to effectively reduce the severity of fetal lung injury. PMID:23111115

Imaging hydration and dehydration across the Cascadia subduction zone (Invited)

NASA Astrophysics Data System (ADS)

Abers, G. A.; Van Keken, P. E.; Hacker, B. R.; Mann, M. E.; Crosbie, K.; Creager, K.

2017-12-01

Arc volcanoes and exhumed forearc metamorphic rocks show clear evidence for upward transport of slab-derived fluids, but geophysical measurements rarely image features that could constrain the mode of this fluid transport. The hottest subduction zones such as Cascadia pose a particular challenge, as the depths where hydrous minerals are stable seaward of trenches is limited, and much of the water is expected to depart the slab before reaching sub-arc depths. Here we improve our understanding of this problem by developing a new thermal model for central Cascadia, leveraging new results several onshore and offshore geophysical investigations, notably the iMUSH project (Imaging Magma Under mount St. Helens), to evaluate constraints on the fluid flux. Offshore onshore heat flow measurements require a cold forearc and preclude detectable shear heating. Several puzzles emerge. The first is that Mount St. Helens overlies a continuous subducting plate which has an upper surface only 65-70 km deep beneath the volcano, imaged by migrated scattered P coda. This location, together with heat flow observations and inferences from the strength of the upper plate Moho, place the volcano over a cold forearc mantle wedge that is substantially hydrated. It is unclear how the wide range of magmas at Mount St. Helens could emerge in this setting since many have mantle origin. A second puzzle is that a large velocity step, about 10% in Vs, is seen along the slab Moho to depths exceeding 90 km where thermal models predict the subducting crust is in eclogite facies; eclogite and peridotite should have nearly indistinguishable Vs. Possibly a gabbroic oceanic crust persists metastably well below the arc, or perhaps the interface represents a deeper hydration front rather than petrologic Moho. A third puzzle is the persistent indication of H2O in arc magmas here despite almost certain dehydration of subducting sediments and upper oceanic crust. This indicates substantial H2O delivered by hydrated mantle lithosphere despite seismic evidence offshore for very little hydration. Perhaps the subducting lower crust carries more H2O than previously thought, or H2O transports structurally downward into the slab after subduction commences. Overall, substantial evidence exists for lateral transport of hydrous fluids in their path from slab to surface.

The Geothermal Systems along the Watukosek fault system (East Java, Indonesia):The Arjuno-Welirang Volcanic Complex and the Lusi Mud-Eruption

NASA Astrophysics Data System (ADS)

Inguaggiato, Salvatore; Mazzini, Adriano; Vita, Fabio; Sciarra, Alessandra

2016-04-01

The Java Island is characterized by an intense volcanic activity with more then 100 active volcanoes. Moreover, this island is also known by the presence of many mud volcanoes and hydrothermal springs. In particular, in the 2006 several sudden hot mud eruptions, with fluids around 100° C, occurred in the NE side of the island resulting in a prominent eruption named Lusi (contraction of Lumpur Sidoarjo) located along the major Watukosek strike-slip fault zone. The Watukosek fault system, strikes from the Arjuno-Welirang volcanic complex, intersects Lusi and extends towards the NE of the Java island. Conversely of the normal mud eruptions (cold fluids emitted in a short time period of few days), the Lusi eruption was characterized by a persistent effusive hot fluids emissions for a long-time period of, so far, nearly a decade. Moreover, the isotopic composition of emitted gases like Helium showed a clear magmatic origin. For this reasons we decided to investigate the near Arjuno-Welirang complex located on the same strike-slip fault. Arjuno-Welirang is a twin strato-volcano system located in the East of Java along the Watukosek fault, at about 25 km SW respect to the Lusi volcano system. It features two main peaks: Arjuno (3339 masl) and Welirang (3156 masl). The last recorded eruptive activity took place in August 1950 from the flanks of Kawah Plupuh and in October 1950 from the NW part of the Gunung Welirang. This strato-volcano is characterized by a S-rich area, with high T-vent fumarole at least up to 220° C (and likely higher), located mainly in the Welirang crater. In addition, several hot springs vent from the flanks of the volcano, indicate the presence of a large hydrothermal system. During July 2015, in the framework of the Lusi Lab project (ERC grant n° 308126), we carried out a geochemical field campaign on the Arjuno-Welirang volcano hydrothermal system area, sampling water and dissolved gases from the thermal and cold springs located on the flanks of the volcano and from two high-T fumaroles located on the summit area of Welirang. Hydrothermal springs reveal temperatures up to 53° C and pH between 6.2 and 8.2. The hydrothermal springs show a volatile content (mainly CO2 and He) that is several order of magnitude higher than the Air Saturated Waters values (ASW) indicating a strong gas/water interaction processes between waters of meteoric origin and deep volatiles of volcanic origin. The hydrothermal springs have dissolved helium isotopic values with clear magmatic signature (R/Ra around 7) that is remarkably close to the helium isotope values from the fumaroles (R/Ra= 7.30). The isotopic composition of helium measured in the fluids emitted from the Lusi mud-volcano around 6.5R/Ra is very similar to the Welirang volcanic fluids indicating the presence of magmatic gases in the Lusi emitted fluids. While the isotopic composition of waters in the Welirang and Lusi fluids are markedly different suggesting a different origin and/or recharge areas for these two hydrothermal systems. These data support the hypothesis that the presence of volcanic gases could have triggered and conveyed the hot and persistent mud fluids emissions of Lusi volcano.

Investigation of extractable organic compounds in deep-sea hydrothermal vent fluids along the Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

McCollom, Thomas M.; Seewald, Jeffrey S.; German, Christopher R.

2015-05-01

The possibility that deep-sea hydrothermal vents may contain organic compounds produced by abiotic synthesis or by microbial communities living deep beneath the surface has led to numerous studies of the organic composition of vent fluids. Most of these studies have focused on methane and other light hydrocarbons, while the possible occurrence of more complex organic compounds in the fluids has remained largely unstudied. To address this issue, the presence of higher molecular weight organic compounds in deep-sea hydrothermal fluids was assessed at three sites along the Mid-Atlantic Ridge that span a range of temperatures (51 to >360 °C), fluid compositions, and host-rock lithologies (mafic to ultramafic). Samples were obtained at several sites within the Lucky Strike, Rainbow, and Lost City hydrothermal fields. Three methods were employed to extract organic compounds for analysis, including liquid:liquid extraction, cold trapping on the walls of a coil of titanium tubing, and pumping fluids through cartridges filled with solid phase extraction (SPE) sorbents. The only samples to consistently yield high amounts of extractable organic compounds were the warm (51-91 °C), highly alkaline fluids from Lost City, which contained elevated concentrations of C8, C10, and C12n-alkanoic acids and, in some cases, trithiolane, hexadecanol, squalene, and cholesterol. Collectively, the C8-C12 acids can account for about 15% of the total dissolved organic carbon in the Lost City fluids. The even-carbon-number predominance of the alkanoic acids indicates a biological origin, but it is unclear whether these compounds are derived from microbial activity occurring within the hydrothermal chimney proximal to the site of fluid discharge or are transported from deeper within the system. Hydrothermal fluids from the Lucky Strike and Rainbow fields were characterized by an overall scarcity of extractable dissolved organic compounds. Trace amounts of aromatic hydrocarbons including phenanthrenes and benzothiophene were the only compounds that could be identified as indigenous components of these fluids. Although hydrocarbons and fatty acids were observed in some samples, those compounds were likely derived from particulate matter or biomass entrained during fluid collection. In addition, extracts of some fluid samples from the Rainbow field were found to contain an unresolved complex mixture (UCM) of organic compounds. This UCM shared some characteristics with organic matter extracted from bottom seawater, suggesting that the organic matter observed in these samples might represent seawater-derived compounds that had persisted, albeit with partial alteration, during circulation through the hydrothermal system. While there is considerable evidence that Rainbow and Lost City vent fluids contain methane and other light hydrocarbons produced through abiotic reduction of inorganic carbon, we found no evidence for more complex organic compounds with an abiotic origin in the same fluids.

Empyema necessitans in a six-month-old girl.

PubMed

Goussard, P; Gie, Robert; Janson, Jacques; Andronikou, Savvas

2018-05-23

Empyema necessitans is a rare complication of acute bacterial pneumonia, especially in children. It is a complication of empyema characterised by the extension of pus from the pleural cavity into the thoracic wall to form a mass of purulent fluid in the adjacent soft tissue. An inflammatory chest wall mass following pneumonia caused by Streptococcus pneumonia in a six-month-old infant is reported. The case emphasises that children presenting with persistent fever and a painful chest wall mass following pneumonia should be investigated immediately as there might be an urgent need for surgery.

On Multiple-Layered Vortices

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.

2011-01-01

As part of an ongoing effort to find ways to make vortex flow fields decompose more quickly, photographs and observations are presented of vortex flow fields that indicate the presence of multiple layers of fluid rotating about a common axis. A survey of the literature indicates that multiple-layered vortices form in waterspouts, tornadoes and lift-generated vortices of aircraft. An explanation for the appearance of multiple-layered structures in vortices is suggested. The observations and data presented are intended to improve the understanding of the formation and persistence of vortex flow fields.

Convection induced by selective absorption of radiation: A laboratory model of conditional instability

NASA Astrophysics Data System (ADS)

Krishnamurti, Ruby

1998-01-01

When there is internal heating in a fluid layer, convection can occur even if the static state is one of stable stratification. We have been investigating through laboratory experiments such a stably stratified layer of water which is heated above and cooled below. The water contains in dilute solution thymol blue (a pH indicator), which normally colors the water orange. It turns yellow if the pH is low, blue if the pH is high. A small DC voltage is applied across the layer, by using the bottom boundary as the positive electrode, the top boundary as the negative electrode. The hydroxyl ions formed near the bottom boundary cause the orange fluid to turn blue. The fluid layer is uniformly and steadily illuminated from above with light from a sodium vapor lamp. This radiation travels with negligible absorption through the orange fluid but is strongly absorbed by the blue fluid. The resultant warming of the blue fluid can lead to convective instability, with the blue fluid rising into warm upper layers, which it would continue to penetrate as long as it remains blue and as long as the radiative heating is sufficient to exceed the higher ambient temperatures above. This radiative heating occurs only in the blue rising flow; the sinking fluid is orange and is not heated. We have found that with a strongly stably stratified layer, convective plumes are unable to penetrate far and they remain shallow. However, for a weakly stratified layer, plumes grow tall and furthermore collect into a large convective cluster which persists as a steady coherent structure. The present paper deals also with the formulation of the governing equations to include the fluid-state-dependent heat source. A linear stability analysis shows that the critical Rayleigh number for onset of motion is drastically reduced. Furthermore, the cell size at onset is larger by a factor of √ 3/2 than in the classical Rayleigh-Benard convection problem. However, the laboratory fluid cells were much further broadened (by a factor of 8 or 10) when they penetrated into the stably stratified fluid above. In this case, the rising region is narrow and the sinking region is broad, so that downward vertical velocities are correspondingly small. In this way, the downwards-forced warm fluid has time to cool by conduction to the cold boundary. Steady finite amplitude solutions and their stability are analyzed and it is shown that there is a parameter range in which finite amplitude hexagonal cells are stable.

Surgical management of failed endoscopic treatment of pancreatic disease.

PubMed

Evans, Kimberly A; Clark, Colby W; Vogel, Stephen B; Behrns, Kevin E

2008-11-01

Endoscopic therapy of acute and chronic pancreatitis has decreased the need for operative intervention. However, a significant proportion of patients treated endoscopically require definitive surgical management for persistent symptoms. Our aim was to determine which patients are likely to fail with endoscopic therapy, and to assess the clinical outcome of surgical management. Patients were identified using ICD-9 codes for pancreatic disease as well as CPT codes for endoscopic therapy followed by surgery. Patients with documented acute or chronic pancreatitis treated endoscopically prior to surgical therapy were included (N = 88). The majority of patients (65%) exhibited chronic pancreatitis due to alcohol abuse. Common indicators for surgery were: persistent symptoms, anatomy not amenable to endoscopic treatment and unresolved common bile duct or pancreatic duct strictures. Surgical salvage procedures included internal drainage of a pseudocyst or an obstructed pancreatic duct (46%), debridement of peripancreatic fluid collections (25%), and pancreatic resection (31%). Death occurred in 3% of patients. The most common complications were hemorrhage (16%), wound infection (13%), and pulmonary complications (11%). Chronic pancreatitis with persistent symptoms is the most common reason for pancreatic surgery following endoscopic therapy. Surgical salvage therapy can largely be accomplished by drainage procedures, but pancreatic resection is common. These complex procedures can be performed with acceptable mortality but also with significant risk for morbidity.

Biophysics of biofilm infection.

PubMed

Stewart, Philip S

2014-04-01

This article examines a likely basis of the tenacity of biofilm infections that has received relatively little attention: the resistance of biofilms to mechanical clearance. One way that a biofilm infection persists is by withstanding the flow of fluid or other mechanical forces that work to wash or sweep microorganisms out of the body. The fundamental criterion for mechanical persistence is that the biofilm failure strength exceeds the external applied stress. Mechanical failure of the biofilm and release of planktonic microbial cells is also important in vivo because it can result in dissemination of infection. The fundamental criterion for detachment and dissemination is that the applied stress exceeds the biofilm failure strength. The apparent contradiction for a biofilm to both persist and disseminate is resolved by recognizing that biofilm material properties are inherently heterogeneous. There are also mechanical aspects to the ways that infectious biofilms evade leukocyte phagocytosis. The possibility of alternative therapies for treating biofilm infections that work by reducing biofilm cohesion could (1) allow prevailing hydrodynamic shear to remove biofilm, (2) increase the efficacy of designed interventions for removing biofilms, (3) enable phagocytic engulfment of softened biofilm aggregates, and (4) improve phagocyte mobility and access to biofilm. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

First report on the diagnosis and treatment of encephalic and urinary paracoccidioidomycosis in a cat.

PubMed

Gonzalez, Juan F; Montiel, Nestor A; Maass, Rodrigo L

2010-08-01

A male Persian cat was presented with persistent fever, anorexia, weakness, hypopyon, nystagmus, and intention tremors. The hemogram showed severe neutropenia and laboratory analysis on cerebrospinal fluid (CSF) smears revealed abundant yeast cells compatible with Paracoccidioides brasiliensis. Urinalysis demonstrated persistent funguria and an increased urine protein-to-creatinine ratio (UPC) in addition to mild azotemia. Long-term therapy with oral fluconazole was effective in controlling the nervous system signs. Funguria was resolved with subcutaneous administration of diluted amphotericin B in a large volume of saline solution for a period of 12 weeks during the second year after initial diagnosis. Throughout 5 years of treatment, no adverse effects were observed and tolerance to the drugs was normal. Due to development of progressive uremic syndrome the animal was euthanased. To the best of our knowledge, this report is the first clinical case described of a nervous and urinary system infection caused by the P brasiliensis in a cat. Copyright 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

A New Paradigm for Diagnosing Contributions to Model Aerosol Forcing Error

NASA Astrophysics Data System (ADS)

Jones, A. L.; Feldman, D. R.; Freidenreich, S.; Paynter, D.; Ramaswamy, V.; Collins, W. D.; Pincus, R.

2017-12-01

A new paradigm in benchmark absorption-scattering radiative transfer is presented that enables both the globally averaged and spatially resolved testing of climate model radiation parameterizations in order to uncover persistent sources of biases in the aerosol instantaneous radiative effect (IRE). A proof of concept is demonstrated with the Geophysical Fluid Dynamics Laboratory AM4 and Community Earth System Model 1.2.2 climate models. Instead of prescribing atmospheric conditions and aerosols, as in prior intercomparisons, native snapshots of the atmospheric state and aerosol optical properties from the participating models are used as inputs to an accurate radiation solver to uncover model-relevant biases. These diagnostic results show that the models' aerosol IRE bias is of the same magnitude as the persistent range cited ( 1 W/m2) and also varies spatially and with intrinsic aerosol optical properties. The findings underscore the significance of native model error analysis and its dispositive ability to diagnose global biases, confirming its fundamental value for the Radiative Forcing Model Intercomparison Project.

Changes in surface temperature at Taal Volcano, Philippines 1965-1966

USGS Publications Warehouse

Moxham, R.M.

1967-01-01

Taal Volcano erupted in September 1965 ending a dormant period of 54 years. A quiescent interval of 9 months followed, terminated by new eruptions in July 1966 at the same site. Aerial surveys with a scanning infrared radiometer were made at three periods during the quiescent interval and twice following the July 1966 eruption. The survey technique yields a quasiphotographic image of the radiant temperature of the volcanic terrain. Results indicate that the principal changes in surface temperature stemmed from changes in convective heat transfer by hydrothermal fluids. New hot springs developed along the structurally-controlled northwest and southeast flanks of the 1965 explosion crater. The northwest spring grew in size prior to the 1966 eruption, persisted through that eruption and has since maintained its discharge. The 1965 cinder cone meanwhile showed a persistent rim of hydrothermal activity with some shift in position of maximum discharge. The July 1966 eruptions took place on the rim about midway between two positions of maximum discharge.

Coherent Structure Detection using Persistent Homology and other Topological Tools

NASA Astrophysics Data System (ADS)

Smith, Spencer; Roberts, Eric; Sindi, Suzanne; Mitchell, Kevin

2017-11-01

For non-autonomous, aperiodic fluid flows, coherent structures help organize the dynamics, much as invariant manifolds and periodic orbits do for autonomous or periodic systems. The prevalence of such flows in nature and industry has motivated many successful techniques for defining and detecting coherent structures. However, often these approaches require very fine trajectory data to reconstruct velocity fields and compute Cauchy-Green-tensor-related quantities. We use topological techniques to help detect coherent trajectory sets in relatively sparse 2D advection problems. More specifically, we have developed a homotopy-based algorithm, the ensemble-based topological entropy calculation (E-tec), which assigns to each edge in an initial triangulation of advected points a topologically forced lower bound on its future stretching rate. The triangulation and its weighted edges allow us to analyze flows using persistent homology. This topological data analysis tool detects clusters and loops in the triangulation that are robust in the presence of noise and in this case correspond to coherent trajectory sets.

Acute caecal volvulus: A diagnostic paradigm.

PubMed

Chaudry, Tariq Hassan; Jamil, Munawar; Niaz, Khurram; Basher, Goher

2015-12-01

Acute Caecal Volvulus is a rare etiology in cases of Intestinal obstruction. We are presenting the data of 11 cases out of 1032 cases of intestinal obstruction between June 2008 to June 2013, who presented in the emergency department of Bahawal Victoria Hospital Bahawalpur. The mean age was 36±3.38 years with female preponderance in this retrospective study. The persistent distinctive features were chronic intermittent pain followed by the passage of flatus (54%), severe right lower quadrant colicky pain (31%) and abdominal distention (59%). Radiologically the dilated caecum with air fluid level (68%) was persistent finding with lateralization of small gut in few patients (12%). Cecopexy (18%), right Hemicolectomy with primary anastomosis (63.63%) and Ileostomy with mucous fistula (18%) were offered. Wound sepsis (27%) and chest infection (18%) were common sequele. Acute Caecal Volvulus diagnosis requires a heightened clinical suspicion on the basis of symptoms like RLQ pain/mass which is relieved by passage of flatus and early radiological assistance in all cases of intestinal obstruction.

Anterior cruciate ligament allograft transplantation in dogs.

PubMed

Vasseur, P B; Stevenson, S; Gregory, C R; Rodrigo, J J; Pauli, S; Heitter, D; Sharkey, N

1991-08-01

The biomechanical and clinical performance of bone-ligament-bone anterior cruciate ligament (ACL) allografts was studied in eight dogs. Allografts were collected from skeletally mature, healthy dogs using aseptic technique, and stored at -70 degrees for three to five weeks before implantation. The allografts were size-matched to the recipient dogs using ACL length and then rigidly fixed in position with interference screws and Kirschner wires. Three dogs regained a normal gait, and their grafts sustained breaking loads that were 25%, 41%, and 59% of controls. Partial or complete graft failure occurred in the other five dogs at some point in the study. Four had intraligamentous rupture and one had an avulsion fracture of the femoral attachment site. Joint-fluid cytology was normal in all eight dogs. Histologic examination showed persistent lymphoplasmacytic infiltrate. Eventually the allograft cores were incorporated in the host bed. Hyperplasia and fibrosis of the synovial membrane were diffuse and persisted as focal accumulations of mononuclear inflammatory cells.

Discovering Coherent Structures Using Local Causal States

NASA Astrophysics Data System (ADS)

Rupe, Adam; Crutchfield, James P.; Kashinath, Karthik; Prabhat, Mr.

2017-11-01

Coherent structures were introduced in the study of fluid dynamics and were initially defined as regions characterized by high levels of coherent vorticity, i.e. regions where instantaneously space and phase correlated vorticity are high. In a more general spatiotemporal setting, coherent structures can be seen as localized broken symmetries which persist in time. Building off the computational mechanics framework, which integrates tools from computation and information theory to capture pattern and structure in nonlinear dynamical systems, we introduce a theory of coherent structures, in the more general sense. Central to computational mechanics is the causal equivalence relation, and a local spatiotemporal generalization of it is used to construct the local causal states, which are utilized to uncover a system's spatiotemporal symmetries. Coherent structures are then identified as persistent, localized deviations from these symmetries. We illustrate how novel patterns and structures can be discovered in cellular automata and outline the path from them to laminar, transitional and turbulent flows. Funded by Intel through the Big Data Center at LBNL and the IPCC at UC Davis.

Fluid, electrolyte, and acid-base balances in three-day, combined-training horses.

PubMed

White, S L

1998-04-01

Horses competing in 3-day, combined-training events develop a metabolic acidosis that is partially compensated for by a respiratory alkalosis immediately after phases B and D. By the end of phase C and 30 minutes to 2 hours after phase D, the acidosis is resolved by the oxidation of lactate, and a metabolic alkalosis prevails. A reduction in TBW and cation content occurs, which often is not replenished 12 to 24 hours after the event, even though the serum or plasma concentration of various constituents may be within normal limits. Hypochloremia and hypocalcemia, however, may persist 12 or more hours after the speed and endurance test. All of the data cited in this article are from horses that successfully completed their respective tests. Nevertheless, some horses developed substantial fluid and cation losses. In horses that are not well conditioned or in competitions in which terrain, footing, or hot environments increase the thermal load or decrease heat loss, greater losses of fluids and electrolytes can be expected. Body weight losses exceeding 5% and cation losses exceeding 4000 mEq/L occur in endurance horses suffering from exhaustion and synchronous diaphragmatic flutter. In one study, two thirds of the Na+ lost during exercise-induced sweating in cool, dry conditions was replenished from salt supplements added to a balanced forage and concentrated diet. Consequently, horses in regular training and competition may benefit from salt supplementation. The composition of the salt supplement and the amount fed should be based on the composition of the horse's diet, degree of work, and environmental conditions. Horses competing in a 3-day, combined-training event may be expected to have persistent losses of weight and cations, particularly if conditions result in heavy sweating. Many horses in the field studies had minimal changes in weight and cation balance compared with pre-event values. The diet and electrolyte supplementation of the horses in the majority of these studies were unknown; consequently, no firm conclusions may be made regarding the degree of weight, water, and cationic losses. It is likely that the horse's large intestine serves as a reservoir for both fluid and electrolytes so that performance is not diminished, despite losses demonstrated consistently in treadmill studies. Horses that are inadequately trained or have other systemic or musculoskeletal problems or those that are competing in hot conditions may develop a variety of metabolic problems. It is hoped that knowledge of the fluid and electrolyte losses may help in treating horses with metabolic problems and, more importantly, in improving management of horses in training and competition to prevent any loss of performance.

Genomic characterization of a persistent rubella virus from a case of Fuch' uveitis syndrome in a 73 year old man.

PubMed

Abernathy, Emily; Peairs, Randall R; Chen, Min-hsin; Icenogle, Joseph; Namdari, Hassan

2015-08-01

Many cases of Fuchs' uveitis have been associated with persistent rubella virus infection. A 73-year-old male patient with typical Fuchs' Uveitis Syndrome (FUS) first experienced heterochromia of the left eye at the age fourteen, when rubella was endemic in the US. The purposes of this report are to describe the patient's FUS clinical presentations and to characterize the virus detected in the vitreous fluid. The patient underwent a therapeutic pars plana vitrectomy in May 2013. A real-time RT-PCR assay for rubella virus was performed on the vitreous fluid by Focus Diagnostics. Additional real-time RT-PCR assays for rubella virus detection and RT-PCR assays for generation of templates for sequencing were performed at the Centers for Disease Control and Prevention (CDC). The results from Focus Diagnostics were positive for rubella virus RNA. Real-time RT-PCR assays at CDC were also positive for rubella virus. A rubella virus sequence of 739 nucleotides was determined and phylogenetic analysis showed that the virus was the sole member of a new phylogenetic group when compared to reference virus sequences. While FUS remains a clinical diagnosis, findings in this case support the association between rubella virus and the disease. Phylogenetic analysis provided evidence that this rubella virus was likely a previously undetected genotype which is no longer circulating. Since the patient had rubella prior to 1955, this sequence is from the earliest rubella virus yet characterized. Copyright © 2015 Elsevier B.V. All rights reserved.

Fate of pathogenic bacteria in microcosms mimicking human body sites.

PubMed

Castellani, Francesco; Ghidini, Valentina; Tafi, Maria Carla; Boaretti, Marzia; Lleo, Maria M

2013-07-01

During the infectious process, pathogens may reach anatomical sites where they are exposed to substances interfering with their growth. These substances can include molecules produced by the host, and his resident microbial population, as well as exogenous antibacterial drugs. Suboptimal concentrations of inhibitory molecules and stress conditions found in vivo (high or low temperatures, lack of oxygen, extreme pH) might induce in bacteria the activation of survival mechanisms blocking their division capability but allowing them to stay alive. These "dormant" bacteria can be reactivated in particular circumstances and would be able to express their virulence traits. In this study, it was evaluated the effect of some environmental conditions, such as optimal and suboptimal temperatures, direct light and antibiotic sub-inhibitory concentrations doses of antibiotic, on the human pathogens Escherichia coli and Enterococcus faecalis when incubated in fluids accumulated in the body of patients with different pathologies. It is shown that inoculation in a number of accumulated body fluids and the presence of gentamicin, reliable conditions encountered during pathological states, induce stress-responding strategies enabling bacteria to persist in microcosms mimicking the human body. Significant differences were detected in Gram-negative and Gram-positive species with E. faecalis surviving, as starved or viable but non-culturable forms, in any microcosm and condition tested and E. coli activating a viable but non-culturable state only in some clinical samples. The persistence of bacteria under these conditions, being non-culturable, might explain some recurrent infections without isolation of the causative agent after application of the standard microbiological methods.

Spinal Cord Herniation After Cervical Corpectomy with Cerebrospinal Fluid Leak: Case Report and Review of the Literature.

PubMed

Guppy, Kern H; Silverthorn, James W

2017-04-01

Spinal cord herniation (SCH) is rare, is mostly idiopathic, and occurs predominantly in the thoracic spine. SCH is less common in the cervical spine and has been reported after posterior cervical spine surgery associated with the development of pseudomeningoceles. Two cases of SCH have been reported after anterior cervical corpectomies for ossified posterior longitudinal ligament with cerebrospinal fluid (CSF) leaks. We report the third such case, but the first in a patient without ossified posterior longitudinal ligament (degenerative disc disease and pseudarthrosis). A 56-year-old woman presented with bilateral arm pain and weakness. She had undergone 3 previous anterior cervical spine surgeries at an outside medical center with the most recent 7 years ago with C5 and C6 corpectomies and fusion with a persistent CSF leak. Magnetic resonance imaging and computed tomography myelography showed spinal cord herniation through the mesh cage at C6. The patient underwent a redo C5 and C6 corpectomy with untethering of the spinal cord. The patient was asymptomatic 2 years later. This is the first reported case of anterior cervical SCH in a patient without ossified posterior longitudinal ligament after multiple anterior cervical fusions including a cervical corpectomy for pseudarthrosis with a CSF leak. We hypothesize that persistent CSF leak causes a pressure gradient across the dura mater through the cage to the lower pressure in the retropharyngeal space, which led to herniation of the spinal cord into the anterior cage. We review the literature and discuss the treatment choices for anterior cervical SCH. Copyright © 2017 Elsevier Inc. All rights reserved.

Acute polyarthritis in a young patient caused by meningococcal and parvovirus B19 infections: a case report and review of the literature.

PubMed

Lavoipierre, Virginie; Dellyes, Anna; Aubry, Camille; Zandotti, Christine; Lafforgue, Pierre; Parola, Philippe; Lagier, Jean-Christophe

2016-12-20

Meningococcal infection is a multifaceted disease including acute polyarthritis. This presentation should be known by clinicians in order to prevent delay in treatment. We report what we believe to be the first case of an association of parvovirus B19 and meningococcal polyarthritis in a young adult. A 19-year-old Caucasian woman presented to our hospital with fever, intense leg pain, and a transient rash. A physical examination showed asymmetric polyarthritis and no neurological abnormalities. A parvovirus B19 polymerase chain reaction performed using a blood sample and knee fluid aspirate came back positive, but serology was negative for immunoglobulin M and positive for immunoglobulin G. A blood culture was positive for serotype C meningococcus; a polymerase chain reaction performed for Neisseria meningitidis was positive in joint fluid but negative in blood samples (performed after antibiotic treatment had begun). Our patient was treated with ceftriaxone for 15 days, associated with analgesic therapy. Hydroxychloroquine treatment was introduced 5 months after the onset of polyarthritis because of persisting inflammatory arthralgia. To the best of our knowledge, this is the first case report of polyarthritis caused by concomitant meningococcal and parvovirus B19 infections. This unusual presentation of meningococcal disease may have resulted from the persistent parvovirus B19 infection. Our experience with this case illustrates the need for a systematic approach to the diagnosis of febrile acute polyarthritis. Only long-term follow-up will reveal if this infectious polyarthritis will evolve towards an autoimmune rheumatism.

Longitudinal Analysis of Cerebrospinal Fluid and Plasma HIV-1 Envelope Sequences Isolated From a Single Donor with HIV Asymptomatic Neurocognitive Impairment

PubMed Central

Vázquez-Santiago, Fabián; García, Yashira; Rivera-Román, Ivelisse; Noel, Richard J.; Wojna, Valerie; Meléndez, Loyda M.; Rivera-Amill, Vanessa

2015-01-01

Objective Combined antiretroviral treatment (cART) has changed the clinical presentation of HIV-associated neurocognitive disorders (HAND) to that of the milder forms of the disease. Asymptomatic neurocognitive impairment (ANI) is now more prevalent and is associated with increased morbidity and mortality risk in HIV-1–infected people. HIV-1 envelope (env) genetic heterogeneity has been detected within the central nervous system (CNS) of individuals with ANI. Changes within env determine co-receptor use, cellular tropism, and neuropathogenesis. We hypothesize that compartmental changes are associated with HIV-1 env C2V4 during ANI and sought to analyze paired HIV-1 env sequences from plasma and cerebrospinal fluid (CSF) of a female subject undergoing long-term cART. Methods Paired plasma and CSF samples were collected at 12-month intervals and HIV-1 env C2V4 was cloned and sequenced. Results Phylogenetic analysis of paired samples consistently showed genetic variants unique to the CSF. Phenotypic prediction showed CCR5 (R5) variants for all CSF-derived sequences and showed minor X4 variants (or dual-tropic) in the plasma at later time points. Viral compartmentalization was evident throughout the study, suggesting that the occurrence of distinctive env strains may contribute to the neuropathogenesis of HAND. Conclusions Our study provides new insights about the genetic characteristics within the C2V4 of HIV-1 env that persist after long-term cART and during the course of persistent ANI. PMID:26167513

The first effects of fluid inertia on flows in ordered and random arrays of spheres

NASA Astrophysics Data System (ADS)

Hill, Reghan J.; Koch, Donald L.; Ladd, Anthony J. C.

2001-12-01

Theory and lattice-Boltzmann simulations are used to examine the effects of fluid inertia, at small Reynolds numbers, on flows in simple cubic, face-centred cubic and random arrays of spheres. The drag force on the spheres, and hence the permeability of the arrays, is determined at small but finite Reynolds numbers, at solid volume fractions up to the close-packed limits of the arrays. For small solid volume fraction, the simulations are compared to theory, showing that the first inertial contribution to the drag force, when scaled with the Stokes drag force on a single sphere in an unbounded fluid, is proportional to the square of the Reynolds number. The simulations show that this scaling persists at solid volume fractions up to the close-packed limits of the arrays, and that the first inertial contribution to the drag force relative to the Stokes-flow drag force decreases with increasing solid volume fraction. The temporal evolution of the spatially averaged velocity and the drag force is examined when the fluid is accelerated from rest by a constant average pressure gradient toward a steady Stokes flow. Theory for the short- and long-time behaviour is in good agreement with simulations, showing that the unsteady force is dominated by quasi-steady drag and added-mass forces. The short- and long-time added-mass coefficients are obtained from potential-flow and quasi-steady viscous-flow approximations, respectively.

Steady finite-Reynolds-number flows in three-dimensional collapsible tubes

NASA Astrophysics Data System (ADS)

Hazel, Andrew L.; Heil, Matthias

2003-07-01

A fully coupled finite-element method is used to investigate the steady flow of a viscous fluid through a thin-walled elastic tube mounted between two rigid tubes. The steady three-dimensional Navier Stokes equations are solved simultaneously with the equations of geometrically nonlinear Kirchhoff Love shell theory. If the transmural (internal minus external) pressure acting on the tube is sufficiently negative then the tube buckles non-axisymmetrically and the subsequent large deformations lead to a strong interaction between the fluid and solid mechanics. The main effect of fluid inertia on the macroscopic behaviour of the system is due to the Bernoulli effect, which induces an additional local pressure drop when the tube buckles and its cross-sectional area is reduced. Thus, the tube collapses more strongly than it would in the absence of fluid inertia. Typical tube shapes and flow fields are presented. In strongly collapsed tubes, at finite values of the Reynolds number, two ’jets‘ develop downstream of the region of strongest collapse and persist for considerable axial distances. For sufficiently high values of the Reynolds number, these jets impact upon the sidewalls and spread azimuthally. The consequent azimuthal transport of momentum dramatically changes the axial velocity profiles, which become approximately uTheta-shaped when the flow enters the rigid downstream pipe. Further convection of momentum causes the development of a ring-shaped velocity profile before the ultimate return to a parabolic profile far downstream.

Total Fluid and Water Consumption and the Joint Effect of Exposure to Disinfection By-Products on Risk of Bladder Cancer

PubMed Central

Michaud, Dominique S.; Kogevinas, Manolis; Cantor, Kenneth P.; Villanueva, Cristina M.; Garcia-Closas, Monteserrat; Rothman, Nathaniel; Malats, Nuria; Real, Francisco X.; Serra, Consol; Garcia-Closas, Reina; Tardon, Adonina; Carrato, Alfredo; Dosemeci, Mustafa; Silverman, Debra T.

2007-01-01

Background Findings on water and total fluid intake and bladder cancer are inconsistent; this may, in part, be due to different levels of carcinogens in drinking water. High levels of arsenic and chlorinated by-products in drinking water have been associated with elevated bladder cancer risk in most studies. A pooled analysis based on six case–control studies observed a positive association between tap water and bladder cancer but none for nontap fluid intake, suggesting that contaminants in tap water may be responsible for the excess risk. Objectives We examined the association between total fluid and water consumption and bladder cancer risk, as well as the interaction between water intake and trihalomethane (THM) exposure, in a large case–control study in Spain. Methods A total of 397 bladder cancer cases and 664 matched controls were available for this analysis. Odds ratios (OR) were estimated using unconditional logistic regression, controlling for potential confounders. Results Total fluid intake was associated with a decrease in bladder cancer risk [OR = 0.62; 95% confidence interval (CI), 0.40–0.95 for highest vs. lowest quintile comparison]. A significant inverse association was observed for water intake (for > 1,399 vs. < 400 mL/day, OR = 0.47; 95% CI, 0.33–0.66; p for trend < 0.0001), but not for other individual beverages. The inverse association between water intake and bladder cancer persisted within each level of THM exposure; we found no statistical interaction (p for interaction = 0.13). Conclusion Findings from this study suggest that water intake is inversely associated with bladder cancer risk, regardless of THM exposure level. PMID:18007986

Direct visualization of antigen-specific T cells: HTLV-1 Tax11-19- specific CD8(+) T cells are activated in peripheral blood and accumulate in cerebrospinal fluid from HAM/TSP patients.

PubMed

Greten, T F; Slansky, J E; Kubota, R; Soldan, S S; Jaffee, E M; Leist, T P; Pardoll, D M; Jacobson, S; Schneck, J P

1998-06-23

Human T lymphotropic virus type 1 (HTLV-1) -associated myelopathy/tropic spastic paraparesis is a demyelinating inflammatory neurologic disease associated with HTLV-1 infection. HTLV-1 Tax11-19-specific cytotoxic T cells have been isolated from HLA-A2-positive patients. We have used a peptide-loaded soluble HLA-A2-Ig complex to directly visualize HTLV-1 Tax11-19-specific T cells from peripheral blood and cerebrospinal fluid without in vitro stimulation. Five of six HTLV-1-associated myelopathy/tropic spastic paraparesis patients carried a significant number (up to 13.87%) of CD8(+) lymphocytes specific for the HTLV-1 Tax11-19 peptide in their peripheral blood, which were not found in healthy controls. Simultaneous comparison of peripheral blood and cerebrospinal fluid from one patient revealed 2.5-fold more Tax11-19-specific T cells in the cerebrospinal fluid (23.7% vs. 9.4% in peripheral blood lymphocyte). Tax11-19-specific T cells were seen consistently over a 9-yr time course in one patient as far as 19 yrs after the onset of clinical symptoms. Further analysis of HTLV-1 Tax11-19-specific CD8(+) T lymphocytes in HAM/TSP patients showed different expression patterns of activation markers, intracellular TNF-alpha and gamma-interferon depending on the severity of the disease. Thus, visualization of antigen-specific T cells demonstrates that HTLV-1 Tax11-19-specific CD8(+) T cells are activated, persist during the chronic phase of the disease, and accumulate in cerebrospinal fluid, showing their pivotal role in the pathogenesis of this neurologic disease.

Behavioral responses and fluid regulation in male rats after combined dietary sodium deficiency and water deprivation.

PubMed

Lucia, Kimberly J; Curtis, Kathleen S

2018-02-01

Most investigators use a single treatment such as water deprivation or dietary sodium deficiency to evaluate thirst or sodium appetite, which underlie behavioral responses to body fluid challenges. The goal of the present experiments was to assess the effects of combined treatments in driving behaviors. Therefore, we evaluated the effect of combined overnight water deprivation and dietary sodium deficiency on water intake and salt intake by adult male rats in 2-bottle (0.5M NaCl and water) tests. Overnight water deprivation alone increased water intake, and 10days of dietary sodium deficiency increased 0.5M NaCl intake, with a secondary increase in water intake. During combined water deprivation and dietary sodium deficiency, water intake was enhanced and 0.5M NaCl was reduced, but not eliminated, suggesting that physiologically relevant behavioral responses persist. Nonetheless, the pattern of fluid intake was altered by the combined treatments. We also assessed the effect of these behaviors on induced deficits in body sodium and fluid volume during combined treatments and found that, regardless of treatment, fluid ingestion partially repleted the induced deficits. Finally, we examined urine volume and sodium excretion during dietary sodium deficiency with or without overnight water deprivation and found that, whether or not rats were water deprived, and regardless of water consumption, sodium excretion was minimal. Thus, the combination of water deprivation and dietary sodium deficiency appears to arouse drives that stimulate compensatory behavioral responses. These behaviors, in conjunction with physiological adaptations to the treatments, underlie body sodium and volume repletion in the face of combined water deprivation and dietary sodium deficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

Stimulation of Ebola virus production from persistent infection through activation of the Ras/MAPK pathway.

PubMed

Strong, James E; Wong, Gary; Jones, Shane E; Grolla, Allen; Theriault, Steven; Kobinger, Gary P; Feldmann, Heinz

2008-11-18

Human infections with Ebola virus (EBOV) result in a deadly viral disease known as Ebola hemorrhagic fever. Up to 90% of infected patients die, and there is no available treatment or vaccine. The sporadic human outbreaks are believed to result when EBOV "jumps" from an infected animal to a person and is subsequently transmitted between persons by direct contact with infected blood or body fluids. This study was undertaken to investigate the mechanism by which EBOV can persistently infect and then escape from model cell and animal reservoir systems. We report a model system in which infection of mouse and bat cell lines with EBOV leads to persistence, which can be broken with low levels of lipopolysaccharide or phorbol-12-myristate-13-acetate (PMA). This reactivation depends on the Ras/MAPK pathway through inhibition of RNA-dependent protein kinase and eukaryotic initiation factor 2alpha phosphorylation and occurs at the level of protein synthesis. EBOV also can be evoked from mice 7 days after infection by PMA treatment, indicating that a similar mechanism occurs in vivo. Our findings suggest that EBOV may persist in nature through subclinical infection of a reservoir species, such as bats, and that appropriate physiological stimulation may result in increased replication and transmission to new hosts. Identification of a presumptive mechanism responsible for EBOV emergence from its reservoir underscores the "hit-and-run" nature of the initiation of human and/or nonhuman primate EBOV outbreaks and may provide insight into possible countermeasures to interfere with transmission.

Stimulation of Ebola virus production from persistent infection through activation of the Ras/MAPK pathway

PubMed Central

Strong, James E.; Wong, Gary; Jones, Shane E.; Grolla, Allen; Theriault, Steven; Kobinger, Gary P.; Feldmann, Heinz

2008-01-01

Human infections with Ebola virus (EBOV) result in a deadly viral disease known as Ebola hemorrhagic fever. Up to 90% of infected patients die, and there is no available treatment or vaccine. The sporadic human outbreaks are believed to result when EBOV “jumps” from an infected animal to a person and is subsequently transmitted between persons by direct contact with infected blood or body fluids. This study was undertaken to investigate the mechanism by which EBOV can persistently infect and then escape from model cell and animal reservoir systems. We report a model system in which infection of mouse and bat cell lines with EBOV leads to persistence, which can be broken with low levels of lipopolysaccharide or phorbol-12-myristate-13-acetate (PMA). This reactivation depends on the Ras/MAPK pathway through inhibition of RNA-dependent protein kinase and eukaryotic initiation factor 2α phosphorylation and occurs at the level of protein synthesis. EBOV also can be evoked from mice 7 days after infection by PMA treatment, indicating that a similar mechanism occurs in vivo. Our findings suggest that EBOV may persist in nature through subclinical infection of a reservoir species, such as bats, and that appropriate physiological stimulation may result in increased replication and transmission to new hosts. Identification of a presumptive mechanism responsible for EBOV emergence from its reservoir underscores the “hit-and-run” nature of the initiation of human and/or nonhuman primate EBOV outbreaks and may provide insight into possible countermeasures to interfere with transmission. PMID:18981410

What goes up might come down: Backflow in the conduits of persistently degassing volcanoes and ramifications for melt-inclusion analysis

NASA Astrophysics Data System (ADS)

Suckale, J.; Qin, Z.; Picchi, D.; Keller, T.

2017-12-01

Many active volcanoes erupt significantly less magma than they degas, implying that large quantities of magma must descend back into the plumbing system after degassing. The resulting bidirectional flow field in the volcanic conduit is fundamentally unstable. These instabilities are important to understand, because they likely control the episodicity of eruptive behavior observed at persistently degassing volcanoes. Laboratory experiments have provided invaluable insights into the flow regimes that may arise in volcanic conduits, but are not straightforward to scale up to volcanic systems. The goal of this study is to use direct numerical simulations to virtually reproduce the analogue experiments by Stevenson and Blake, 1998, compare them to simple analytical models and gain insights into the different flow regimes and interface instabilities observed in actual volcanic conduits. Direct numerical simulations provide a compelling complement to analogue experiments, because they are not constrained by the scales or flow properties achievable in a laboratory setting. By linking virtual and analogue experiments, we show that the interface between ascending and descending fluid is not usually stationary in volcanic conduits (see fig). The intuition that buoyant, volatile-rich magma moves up while heavy, degassed magma moves down is hence not generally true in bidirectional conduit flow. Instead, our results show that a potentially significant portion of the volatile-rich magma flows downwards despite its positive buoyancy - a process commonly referred to as backflow. The existence of backflow in volcanic conduits has potentially important ramifications for understanding melt-inclusion trends, because it affects exsolved and dissolved volatile components differently. Our preliminary results suggest that carbon dioxide bubbles exsolved at depth tend to decouple from the backflow and escape into the upward moving portion of the fluid, while dissolved water is recycled back to depth. The ascending magma, which is likely sampled by eruptive products, is hence enriched in carbon dioxide but deprived of water, which could be reflected in the common observation that melt inclusions from persistently degassing volcanic systems appear to be shifted to higher carbon dioxide contents for a given amount of water.

TGF-β directs trafficking of the epithelial sodium channel ENaC which has implications for ion and fluid transport in acute lung injury

PubMed Central

Peters, Dorothea M.; Vadász, István; Wujak, Łukasz; Wygrecka, Małgorzata; Olschewski, Andrea; Becker, Christin; Herold, Susanne; Papp, Rita; Mayer, Konstantin; Rummel, Sebastian; Brandes, Ralph P.; Günther, Andreas; Waldegger, Siegfried; Eickelberg, Oliver; Seeger, Werner; Morty, Rory E.

2014-01-01

TGF-β is a pathogenic factor in patients with acute respiratory distress syndrome (ARDS), a condition characterized by alveolar edema. A unique TGF-β pathway is described, which rapidly promoted internalization of the αβγ epithelial sodium channel (ENaC) complex from the alveolar epithelial cell surface, leading to persistence of pulmonary edema. TGF-β applied to the alveolar airspaces of live rabbits or isolated rabbit lungs blocked sodium transport and caused fluid retention, which—together with patch-clamp and flow cytometry studies—identified ENaC as the target of TGF-β. TGF-β rapidly and sequentially activated phospholipase D1, phosphatidylinositol-4-phosphate 5-kinase 1α, and NADPH oxidase 4 (NOX4) to produce reactive oxygen species, driving internalization of βENaC, the subunit responsible for cell-surface stability of the αβγENaC complex. ENaC internalization was dependent on oxidation of βENaC Cys43. Treatment of alveolar epithelial cells with bronchoalveolar lavage fluids from ARDS patients drove βENaC internalization, which was inhibited by a TGF-β neutralizing antibody and a Tgfbr1 inhibitor. Pharmacological inhibition of TGF-β signaling in vivo in mice, and genetic ablation of the nox4 gene in mice, protected against perturbed lung fluid balance in a bleomycin model of lung injury, highlighting a role for both proximal and distal components of this unique ENaC regulatory pathway in lung fluid balance. These data describe a unique TGF-β–dependent mechanism that regulates ion and fluid transport in the lung, which is not only relevant to the pathological mechanisms of ARDS, but might also represent a physiological means of acutely regulating ENaC activity in the lung and other organs. PMID:24324142

Plasma lactate concentration as a prognostic biomarker in dogs with gastric dilation and volvulus.

PubMed

Mooney, Erin; Raw, Cameron; Hughes, Dez

2014-09-01

Initial and serial plasma lactate concentrations can be used to guide decision making in individual dogs with GDV but care is necessary in phrasing conversations with owners. Published data suggests that survival is more likely and the chance of complications less in dogs with an initial plasma lactate of <4 mmol/L. An initial lactate >6 mmol/L makes gastric necrosis and greater expense more likely. However, because of the overlap between groups and the good overall survival rates, exploratory laparotomy should always be recommended irrespective of the plasma lactate concentration. Falls in plasma lactate of greater than ~40% after fluid resuscitation are likely to indicate better survival. If the initial plasma lactate concentration is moderately to severely increased (5->10 mmol/L) and a sustained increase in plasma lactate occurs after fluid resuscitation, the cause should be aggressively pursued. Many dogs with persistent hyperlactatemia over 24-48 hours do not survive. Copyright © 2014 Elsevier Inc. All rights reserved.

The effect of gravity modulation on thermosolutal convection in an infinite layer of fluid

NASA Astrophysics Data System (ADS)

Saunders, B. V.; Murray, B. T.; McFadden, G. B.; Coriell, S. R.; Wheeler, A. A.

1992-06-01

The effect of time-periodic vertical gravity modulation on the onset of thermosolutal convection in an infinite horizontal layer with stress-free boundaries is investigated using Floquet theory for the linear stability analysis. Situations for which the fluid layer is stably stratified in either the fingering or diffusive regimes of double-diffusive convection are considered. Results are presented both with and without steady background acceleration. Modulation may stabilize an unstable base solution or destabilize a stable base solution. In addition to synchronous and subharmonic response to the modulation frequency, instability in the double diffusive system can occur via a complex conjugate mode. In the diffusive regime, where oscillatory onset occurs in the unmodulated system, regions of resonant instability occur and exhibit strong coupling with the unmodulated oscillatory frequency. The response to modulation of the fundamental instability of the unmodulated system is described both analytically and numerically; in the double-diffusive system this mode persists under subcritical conditions as a high-frequency lobe.

The effect of gravity modulation on thermosolutal convection in an infinite layer of fluid

NASA Technical Reports Server (NTRS)

Saunders, B. V.; Murray, B. T.; Mcfadden, G. B.; Coriell, S. R.; Wheeler, A. A.

1992-01-01

The effect of time-periodic vertical gravity modulation on the onset of thermosolutal convection in an infinite horizontal layer with stress-free boundaries is investigated using Floquet theory for the linear stability analysis. Situations for which the fluid layer is stably stratified in either the fingering or diffusive regimes of double-diffusive convection are considered. Results are presented both with and without steady background acceleration. Modulation may stabilize an unstable base solution or destabilize a stable base solution. In addition to synchronous and subharmonic response to the modulation frequency, instability in the double diffusive system can occur via a complex conjugate mode. In the diffusive regime, where oscillatory onset occurs in the unmodulated system, regions of resonant instability occur and exhibit strong coupling with the unmodulated oscillatory frequency. The response to modulation of the fundamental instability of the unmodulated system is described both analytically and numerically; in the double-diffusive system this mode persists under subcritical conditions as a high-frequency lobe.

Influence of vascular normalization on interstitial flow and delivery of liposomes in tumors

NASA Astrophysics Data System (ADS)

Ozturk, Deniz; Yonucu, Sirin; Yilmaz, Defne; Burcin Unlu, Mehmet

2015-02-01

Elevated interstitial fluid pressure is one of the barriers of drug delivery in solid tumors. Recent studies have shown that normalization of tumor vasculature by anti-angiogenic factors may improve the delivery of conventional cytotoxic drugs, possibly by increasing blood flow, decreasing interstitial fluid pressure, and enhancing the convective transvascular transport of drug molecules. Delivery of large therapeutic agents such as nanoparticles and liposomes might also benefit from normalization therapy since their transport depends primarily on convection. In this study, a mathematical model is presented to provide supporting evidence that normalization therapy may improve the delivery of 100 nm liposomes into solid tumors, by both increasing the total drug extravasation and providing a more homogeneous drug distribution within the tumor. However these beneficial effects largely depend on tumor size and are stronger for tumors within a certain size range. It is shown that this size effect may persist under different microenvironmental conditions and for tumors with irregular margins or heterogeneous blood supply.

Right Heart Failure in an African Penguin ( Spheniscus demersus ).

PubMed

Cusack, Lara; Field, Cara; McDermott, Alexa; Pogue, Brandon; Clauss, Tonya; Bossart, Gregory; Camus, Alvin

2016-09-01

A 19-year-old male African penguin ( Spheniscus demersus ) was presented with coelomic distention after a 6-week history of lethargy and decreased appetite. Results of radiographs showed loss of coelomic detail, and ultrasound and computed tomography results revealed coelomic fluid and dilated hepatic veins. Echocardiography revealed moderate right atrial enlargement. Findings were consistent with right-sided cardiac disease. Treatment with furosemide initially reduced ascites, but the clinical condition worsened weeks later and enalapril, pimobendan, and sildenafil were added to the medical therapy. At 12 weeks after presentation, results of an echocardiogram revealed persistent right atrioventricular valve regurgitation, moderate ascites, and dilation of hepatic veins. Clinical signs of right heart failure were managed through adjustments in medical therapy and coelomic fluid aspiration, but the bird died 18 weeks after initial presentation. Gross and microscopic findings were consistent with valvular insufficiency and right-sided heart failure. To our knowledge, this case is the first documented report of cardiac disease in an African penguin.

The potential for biologically catalyzed anaerobic methane oxidation on ancient Mars.

PubMed

Marlow, Jeffrey J; Larowe, Douglas E; Ehlmann, Bethany L; Amend, Jan P; Orphan, Victoria J

2014-04-01

This study examines the potential for the biologically mediated anaerobic oxidation of methane (AOM) coupled to sulfate reduction on ancient Mars. Seven distinct fluids representative of putative martian groundwater were used to calculate Gibbs energy values in the presence of dissolved methane under a range of atmospheric CO2 partial pressures. In all scenarios, AOM is exergonic, ranging from -31 to -135 kJ/mol CH4. A reaction transport model was constructed to examine how environmentally relevant parameters such as advection velocity, reactant concentrations, and biomass production rate affect the spatial and temporal dependences of AOM reaction rates. Two geologically supported models for ancient martian AOM are presented: a sulfate-rich groundwater with methane produced from serpentinization by-products, and acid-sulfate fluids with methane from basalt alteration. The simulations presented in this study indicate that AOM could have been a feasible metabolism on ancient Mars, and fossil or isotopic evidence of this metabolic pathway may persist beneath the surface and in surface exposures of eroded ancient terrains.

HSV2 acute retinal necrosis: diagnosis and monitoring with quantitative polymerase chain reaction.

PubMed

Cottet, L; Kaiser, L; Hirsch, H H; Baglivo, E

2009-06-01

To describe a case of HSV2 acute retinal necrosis (ARN) diagnosed and monitored with quantitative polymerase chain reaction (PCR) in ocular fluids. Case report. Quantitative PCR was performed in the aqueous humor (AH) and vitreous using primers specific for herpes virus. A positive PCR was found for HSV2 in the AH (>100,000,000 viral copies - 8.00 log/ml). After therapy, another anterior chamber tap showed a reduction of the viral load at 4.28 log/ml (19205 copies), confirming the efficacy of the treatment. After six months, PCR on the vitreous still showed the presence of HSV2 viral particles in the eye (3.14 log DNA copies/ml, 1379 copies) although the lesion was healed. This case demonstrates that PCR is useful to detect viral DNA in AH and vitreous and to monitor viral activity and therapeutic response. Viral DNA persists in ocular fluids for months in the presence of a healed infection.

Initial Results of Coupling the Output of a Regional Weather Model and a Localized Computational Fluid Dynamics Model at the Atlantic City International Airport

NASA Astrophysics Data System (ADS)

Trout, Joseph; Manson, J. Russell; Rios, Manny; King, David; Decicco, Nicholas

2015-04-01

Wake Vortex Turbulence is the turbulence generated by an aircraft in flight. This turbulence is created by vortices at the tips of the wing that may decay slowly and persist for several minutes after creation. The strength, formation and lifetime of the turbulence and vortices are effected by many things including the weather. Here we present the preliminary results of an investigation of low level wind fields generated by the Weather Research and Forecasting Model and an analysis of historical data. The simulations are used as inputs for the computational fluid dynamics model (OpenFoam) that will be used to investigate the effect of weather on wake turbulence. The initial results of the OpenFoam model are presented elsewhere. Presented here are the initial results from a research grant, ``A Pilot Project to Investigate Wake Vortex Patterns and Weather Patterns at the Atlantic City Airport by the Richard Stockton College of NJ and the FAA''.

Risk of Microgravity-Induced Visual Impairment and Elevated Intracranial Pressure (VIIP)

NASA Technical Reports Server (NTRS)

Otto, Christian

2011-01-01

Eight cases identified, represent 23.5% of the 34 crewmembers flown on the ISS, with inflight visual changes and pre-to-postflight refractive changes. In some cases, the changes were transient while in others they are persistent with varying degrees of visual impairment. (1) Decreased intraocular pressure (IOP) postflight was observed in 3 cases. (2) Fundoscopic exams revealed postflight findings of choroidal folds in 4 cases, optic disc edema in 5 cases and presence of cotton wool spots in 3 cases. (3) Optical coherence tomography (OCT) confirmed findings of choroidal folds and disc edema and documented retinal nerve fiber layer thickening (4 cases). (4) Findings from MRI examinations showed posterior globe flattening (5 cases) and optic nerve sheath distension (6 cases). (5) Opening cerebrospinal fluid (CSF) pressure was elevated in 4 cases postflight reflecting raised intracranial pressure. While the etiology remains unknown, hypotheses speculate that venous insufficiency or hypertension in the brain caused by cephalad fluid shifts during spaceflight are possible mechanisms for ocular changes in astronauts.

The Collaborative Ocular Tuberculosis Study (COTS)-1 Report 3: Polymerase Chain Reaction in the Diagnosis and Management of Tubercular Uveitis: Global Trends.

PubMed

Agarwal, Aniruddha; Agrawal, Rupesh; Gunasekaran, Dinesh Visva; Raje, Dhananjay; Gupta, Bhaskar; Aggarwal, Kanika; Murthy, Somasheila L; Westcott, Mark; Chee, Soon Phaik; Mccluskey, Peter; Su Ling, Ho; Teoh, Stephen; Cimino, Luca; Biswas, Jyotirmay; Narain, Shishir; Agarwal, Manisha; Mahendradas, Padmamalini; Khairallah, Moncef; Jones, Nicholas; Tugal-Tutkun, Ilknur; Babu, Kalpana; Basu, Soumayava; Carreño, Ester; Lee, Richard; Al-Dhibi, Hassan; Bodaghi, Bahram; Invernizzi, Alessandro; Goldstein, Debra A; Herbort, Carl P; Barisani-Asenbauer, Talin; González-López, Julio J; Androudi, Sofia; Bansal, Reema; Moharana, Bruttendu; Mahajan, Sarakshi; Esposti, Simona; Tasiopoulou, Anastasia; Nadarajah, Sengal; Agarwal, Mamta; Abraham, Sharanya; Vala, Ruchi; Singh, Ramandeep; Sharma, Aman; Sharma, Kusum; Zierhut, Manfred; Kon, Onn Min; Cunningham, Emmett; Nguyen, Quan Dong; Pavesio, Carlos; Gupta, Vishali

2017-12-20

To analyze the role of polymerase chain reaction (PCR) of ocular fluids in management of tubercular (TB) anterior, intermediate, posterior, and panuveitis. In Collaborative Ocular Tuberculosis Study (COTS)-1 (25 centers, n = 962), patients with TB-related uveitis were included. 59 patients undergoing PCR of intraocular fluids (18 females; 53 Asian Indians) were included. 59 (6.13%) of COTS-1 underwent PCR analysis. PCR was positive for Mycobacterium TB in 33 patients (23 males; all Asian Indians). 26 patients were PCR negative (18 males). Eight patients with negative PCR had systemic TB. Anti-TB therapy was given in 18 negative and 31 PCR cases. At 1-year follow-up, five patients with positive PCR (15.15%) and three with negative PCR (11.54%) had persistence/worsening of inflammation. Data from COTS-1 suggest that PCR is not commonly done for diagnosing intraocular TB and positive/negative results may not influence management or treatment outcomes in the real world scenario.

Symmetry breaking for drag minimization

NASA Astrophysics Data System (ADS)

Roper, Marcus; Squires, Todd M.; Brenner, Michael P.

2005-11-01

For locomotion at high Reynolds numbers drag minimization favors fore-aft asymmetric slender shapes with blunt noses and sharp trailing edges. On the other hand, in an inertialess fluid the drag experienced by a body is independent of whether it travels forward or backward through the fluid, so there is no advantage to having a single preferred swimming direction. In fact numerically determined minimum drag shapes are known to exhibit almost no fore-aft asymmetry even at moderate Re. We show that asymmetry persists, albeit extremely weakly, down to vanishingly small Re, scaling asymptotically as Re^3. The need to minimize drag to maximize speed for a given propulsive capacity gives one possible mechanism for the increasing asymmetry in the body plans seen in nature, as organisms increase in size and swimming speed from bacteria like E-Coli up to pursuit predator fish such as tuna. If it is the dominant mechanism, then this signature scaling will be observed in the shapes of motile micro-organisms.

Botulinum neurotoxin for management of intractable central leakage through a voice prosthesis in surgical voice restoration.

PubMed

Mullan, G P J; Lee, M T; Clarke, P M

2006-09-01

Rehabilitation of voice and speech after total laryngectomy has become established practice in recent years. A voice prosthesis is placed within a surgically produced fistula between the trachea and upper oesophagus and acts as a one way valve, allowing passage of pulmonary air from the trachea into the oesophagus and preventing aspiration of food and fluid from the oesophagus into the trachea. Persistent leakage through or around these prostheses is a recognized complication, the aetiology of which can vary widely, from mechanical issues with the prostheses themselves to anatomical and physiological issues associated with the reconstructed pharynx. We report a new technique of using Dysport in the management of intractable central leakage due to premature and forceful closure of the upper oesophageal sphincter during swallowing. This resulted in the pooling of fluids around the posterior flange of the prosthesis. This, along with the increased pressure from the muscle contraction, led to central leakage, as identified on videofluoroscopy. An injection of Dysport paralysed the upper oesophageal sphincter, preventing pooling of fluids around the prosthesis and the forcing open of the valve. The effect was to eliminate the leakage, and the patient did not require further injections over the following 22 months.

Ceramides: a potential therapeutic target in pulmonary emphysema.

PubMed

Tibboel, Jeroen; Reiss, Irwin; de Jongste, Johan C; Post, Martin

2013-10-01

The aim of this manuscript was to characterize airway ceramide profiles in a rodent model of elastase-induced emphysema and to examine the effect of pharmacological intervention directed towards ceramide metabolism. Adult mice were anesthetized and treated with an intratracheal instillation of elastase. Lung function was measured, broncho-alveolar lavage fluid collected and histological and morphometrical analysis of lung tissue performed within 3 weeks after elastase injection, with and without sphingomyelinase inhibitors or serine palmitoyltransferase inhibitor. Ceramides in broncho-alveolar lavage (BAL) fluid were quantified by tandem mass spectrometry. BAL fluid showed a transient increase in total protein and IgM, and activated macrophages and neutrophils. Ceramides were transiently upregulated at day 2 after elastase treatment. Histology showed persistent patchy alveolar destruction at day 2 after elastase installation. Acid and neutral sphingomyelinase inhibitors had no effect on BAL ceramide levels, lung function or histology. Addition of a serine palmitoyltransferase inhibitor ameliorated lung function changes and reduced ceramides in BAL. Ceramides were increased during the acute inflammatory phase of elastase-induced lung injury. Since addition of a serine palmitoyltransferase inhibitor diminished the rise in ceramides and ameliorated lung function, ceramides likely contributed to the early phase of alveolar destruction and are a potential therapeutic target in the elastase model of lung emphysema.

Cascadia Slow Earthquakes: Strategies for Time Independent Inversion of Displacement Fields

NASA Astrophysics Data System (ADS)

Szeliga, W. M.; Melbourne, T. I.; Miller, M. M.; Santillan, V. M.

2004-12-01

Continuous observations using Global Positioning System geodesy (CGPS) have revealed periodic slow or silent earthquakes along the Cascadia subduction zone with a spectrum of timing and periodicity. These creep events perturb time series of GPS observations and yield coherent displacement fields that relate to the extent and magnitude of fault displacement. In this study, time independent inversions of the surface displacement fields that accompany eight slow earthquakes characterize slip distributions along the plate interface for each event. The inversions employed in this study utilize Okada's elastic dislocation model and a non- negative least squares approach. Methodologies for optimizing the slip distribution smoothing parameter for a particular station distribution have also been investigated, significantly reducing the number of possible slip distributions and the range of estimates for total moment release for each event. The discretized slip distribution calculated for multiple creep events identifies areas of the Cascadia plate interface where slip persistently recurs. The current hypothesis, that slow earthquakes are modulated by forced fluid flow, leads to the possibility that some regions of the Cascadia plate interface may display fault patches preferentially exploited by fluid flow. Thus, the identification of regions of the plate interface that repeatedly slip during slow events may yield important information regarding the identification of these fluid pathways.

A significant increase in both basal and maximal calcineurin activity following fluid percussion injury in the rat.

PubMed

Kurz, Jonathan E; Parsons, J Travis; Rana, Aniruddha; Gibson, Cynthia J; Hamm, Robert J; Churn, Severn B

2005-04-01

Calcineurin, a neuronally enriched, calcium-stimulated phosphatase, is an important modulator of many neuronal processes, including several that are physiologically related to the pathology of traumatic brain injury. This study examined the effects of moderate, central fluid percussion injury on the activity of this important neuronal enzyme. Animals were sacrificed at several time-points postinjury and cortical, hippocampal, and cerebellar homogenates were assayed for calcineurin activity by dephosphorylation of p-nitrophenol phosphate. A significant brain injury-dependent increase was observed in both hippocampal and cortical homogenates under both basal and maximally-stimulated reaction conditions. This increase persisted 2-3 weeks post-injury. Brain injury did not alter substrate affinity, but did induce a significant increase in the apparent maximal dephosphorylation rate. Unlike the other brain regions, no change in calcineurin activity was observed in the cerebellum following brain injury. No brain region tested displayed a significant change in calcineurin enzyme levels as determined by Western blot, demonstrating that increased enzyme synthesis was not responsible for the observed increase in activity. The data support the conclusion that fluid percussion injury results in increased calcineurin activity in the rat forebrain. This increased activity has broad physiological implications, possibly resulting in altered cellular excitability or a greater likelihood of neuronal cell death.

The replacement of alkyl-phenol ethoxylates to improve the environment acceptability of drilling fluid additives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Getliff, J.M.; James, S.G.

1996-12-31

Alkyl-phenol ethoxylates (APEO) are a class of surfactants which have been used widely in the drilling fluid industry. The popularity of these surfactants is based on their cost effectiveness, availability and the range of hydrophilic-lipophilic balance values obtainable. Studies have shown that APEOs exhibit oestrogenic effects, and can cause sterility in some male aquatic species. This may have subsequent human consequences and such problems have lead to a banning of their use in some countries and agreements to phase out their use e.g. PARCOM recommendation 92/8. The use of APEOs as additives in detergents, lubricants and stuck-pipe release agents formore » drilling fluid applications is discussed. The effectiveness of products formulated with APEOs are directly compared with alternative products which are non-persistent and less damaging to aquatic species. Lubricity measurements using standard and in-house designed equipment and washing tests to compare the efficiency of surfactants are explained and product performance results presented. The results show that alternatives to products containing APEOs are available and that in some cases they show a better technical performance. In addition to the improved environmental acceptability of the base chemicals, the better performance enables lower concentrations to be used, hence reducing the environmental impact even further.« less

Two Bioactive Molecular Weight Fractions of a Conditioned Medium Enhance RPE Cell Survival on Age-Related Macular Degeneration and Aged Bruch's Membrane

PubMed Central

Sugino, Ilene K.; Sun, Qian; Springer, Carola; Cheewatrakoolpong, Noounanong; Liu, Tong; Li, Hong; Zarbin, Marco A.

2016-01-01

Purpose To characterize molecular weight fractions of bovine corneal endothelial cell conditioned medium (CM) supporting retinal pigment epithelium (RPE) cell survival on aged and age-related macular degeneration (AMD) Bruch's membrane. Methods CM was subject to size separation using centrifugal filters. Retentate and filtrate fractions were tested for bioactivity by analyzing RPE survival on submacular Bruch's membrane of aged and AMD donor eyes and behavior on collagen I-coated tissue culture wells. Protein and peptide composition of active fractions was determined by mass spectrometry. Results Two bioactive fractions, 3-kDa filtrate and a 10-50–kDa fraction, were necessary for RPE survival on aged and AMD Bruch's membrane. The 3-kDa filtrate, but not the 10-50–kDa fraction, supported RPE growth on collagen 1‐coated tissue culture plates. Mass spectrometry of the 10-50–kDa fraction identified 175 extracellular proteins, including growth factors and extracellular matrix molecules. Transforming growth factor (TGF)β-2 was identified as unique to active CM. Peptides representing 29 unique proteins were identified in the 3-KDa filtrate. Conclusions These results indicate there is a minimum of two bioactive molecules in CM, one found in the 3-kDa filtrate and one in the 10-50–kDa fraction, and that bioactive molecules in both fractions must be present to ensure RPE survival on Bruch's membrane. Mass spectrometry analysis suggested proteins to test in future studies to identify proteins that may contribute to CM bioactivity. Translational Relevance Results of this study are the first steps in development of an adjunct to cell-based therapy to ensure cell transplant survival and functionality in AMD patients. PMID:26933521

EVEREST study report 3: diagnostic challenges of polypoidal choroidal vasculopathy. Lessons learnt from screening failures in the EVEREST study.

PubMed

Tan, Colin S; Ngo, Wei Kiong; Lim, Louis W; Tan, Nikolle W; Lim, Tock H

2016-10-01

To describe screening failures in the EVEREST study by examining the imaging characteristics that enabled differentiation of polypoidal choroidal vasculopathy (PCV) from cases that were subsequently diagnosed not to be PCV. Post-hoc analysis of 34 patients with PCV reported as screening failures from EVEREST study. Standardised confocal scanning laser indocyanine green angiography (ICGA) images were graded by the Central Reading Centre to confirm PCV diagnosis based on the presence of early focal sub-retinal hyperfluorescence on ICGA and at least one of the following six diagnostic criteria: (1) nodular appearance of polyp(s) on stereoscopic examination, (2) hypofluorescent halo around nodule(s), (3) presence of a branching vascular network, (4) pulsation of polyp(s) on dynamic ICGA, (5) orange sub-retinal nodules on colour fundus photography, or (6) massive sub-macular haemorrhage (≥4 disc areas in size). Additional detailed image grading was performed with stereo-imaging and dynamic early-phase ICGA. Of the 95 screened PCV cases, 34 were excluded: (1) cases not suitable for recruitment as per the study protocol (n = 14), (2) equivocal lesions on ICGA characterised by small hyperfluorescent dots (n = 9), and (3) cases that were definitely not PCV (non-PCV, n = 11), identified by definitive diagnoses which included one case each of micro-aneurysm, retinal angiomatous proliferation, retino-choroidal anastomosis, small type-2 choroidal neovascularisation, retinal pigment epithelial (RPE) window defect and disciform scar; two cases of lesions where the choroidal vessel changed its course; and three cases of late-onset RPE staining. Standardised image grading techniques used in EVEREST study enabled effective differentiation of non-PCV from actual PCV.

Clinical outcomes and predictors of response to photodynamic therapy in symptomatic circumscribed choroidal hemangioma: A retrospective case series

PubMed Central

Ho, Yeen-Fey; Chao, Anne; Chen, Kuan-Jen; Wang, Nan-Kai; Liu, Laura; Chen, Yen-Po; Hwang, Yih-Shiou; Wu, Wei-Chi; Lai, Chi-Chun; Chen, Tun-Lu

2018-01-01

Background To investigate the treatment outcomes and predictors of response to photodynamic therapy (PDT) in patients with symptomatic circumscribed hemangioma (CCH). Methods This retrospective case series examined 20 patients with symptomatic CCH (10 submacular CCHs and10 juxtapapillary CCHs) who underwent standard PDT (wavelength: 662 nm; light dose: 50J/cm2; exposure time: 83 sec) with verteporfin (6mg/m2), either as monotherapy (n = 9) or in association with other treatments (n = 11), of which 7 received intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF). A post-PDT improvement of at least two lines in best-corrected visual acuity (BCVA) was the primary outcome measure. Predictors of response were investigated with binary logistic regression analysis. Results Seventeen (85%) patients received one PDT session, and three patients (15%) underwent PDT at least twice. Ten patients (50%) achieved the primary outcome of a post-PDT BCVA improvement of at least two lines. Macular atrophy and recalcitrant cystoid macular edema in 2 patients. Binary logistic regression analysis revealed that younger age (< 50 years) (P = 0.033), pre-PDT BCVA of ≧20/200 (P = 0.013), exudative retinal detachment resolved within one month after PDT (P = 0.007), and a thinner post-PDT tumor thickness (P = 0.015) were associated with the achievement of a post-PDT BCVA improvement. Additional treatments to PDT including IVI anti-VEGF did not appear to improve visual and anatomical outcomes. Conclusions Symptomatic CCHs respond generally well to PDT. Patients with younger age (< 50 years), pretreatment BCVA≥ 20/200, and thinner foveal edema are most likely to benefit from this approach. PMID:29851977

Retina nerve fiber layer and choroidal thickness changes in obstructive sleep apnea syndrome.

PubMed

Ozge, Gokhan; Dogan, Deniz; Koylu, Mehmet Talay; Ayyildiz, Onder; Akincioglu, Dorukcan; Mumcuoglu, Tarkan; Mutlu, Fatih Mehmet

2016-01-01

The purpose of this study was to determine the effects of obstructive sleep apnea syndrome (OSAS) on the submacular and peripapillary retinal nerve fiber layer (RNFL) and choroidal thickness (ChT). Eighty-four eyes of 42 male patients with OSAS and 112 eyes of 56 aged-matched and body mass index-matched healthy male subjects were enrolled in this case-control study. The ChT and peripapillary RNFL thickness was measured using enhanced depth imaging optical coherence tomography. The ChT and RNFL thickness measurements of the groups were compared, and correlations among the Apnea Hypopnea Index (AHI) values and these measurements were calculated. Right and left eyes were separately evaluated. There were no significant differences in the subfoveal and temporal ChT between the groups (p > 0.05). The OSAS group had significantly thicker ChT at 0.5 and 1.5 mm nasal to the fovea in both eyes than the control group (p < 0.05). The peripapillary ChT were significantly thicker in the OSAS group at all segments except for the temporal and superotemporal segments when compared with the control group (p < 0.05 for all quadrants except temporal and superotemporal). When compared with controls, the OSAS group had significantly thinner nasal RNFL thickness in the right eye (p = 0.01) and thinner mean RNFL thickness in both eyes (p < 0.001). Other RNFL thickness measurements were similar between groups (p > 0.05). Between AHI and mean RNFL thickness showed a median negative correlation (r = - 0.411, p = 0.001). The choroidal thickening in patients with OSAS may be associated with the pathophysiology of the neurodegeneration process of the disease.

Visual and Quantitative Analysis of Cisternography for the Detection of Cerebrospinal Fluid Leakage.

PubMed

Choi, Eun Kyoung; Oh, Jin Kyoung; Park, Sonya Youngju; Yoo, Ikdong; Kim, Dong-Hyun; Chung, Yong-An

2017-06-01

We herein present a case of a 29-year-old man with clear rhinorrhea, which persisted for 8 years following a myringotomy. After cotton pledgets were placed in several different regions of the nasal cavity, cisternography using Tc-99m DTPA was performed to measure the radioactivity of each pledget. Cisternography showed subtle uptake in the nasal cavity. However, intense uptake was detected in the pledget placed in the right eustachian tube orifice, where the pledget:serum count ratio was 10.3:1. The patient underwent duroplasty and cranioplasty, and the rhinorrhea resolved.

Spontaneous bacterial coronary sinus septic thrombophlebitis treated successfully medically.

PubMed

Fournet, Maxime; Behaghel, Albin; Pavy, Carine; Flecher, Erwan; Thebault, Christophe

2014-03-01

A 38-year-old farmer was hospitalized for fever, chills, cough, and chest pain lasting for 7 days. Due to persistent symptoms, patient was referred to hospital. Blood cultures identified oxacillin-sensitive Staphylococcus aureus (OSSA). Transthoracic echocardiography (TTE) showed large pericardial effusion, a mobile heterogeneous mass originating from the coronary sinus ostium, no sign of valvular endocarditis. Pericardiocentesis was done carrying out purulent fluid, microbiological culture isolating an OSSA. Parenteral penicillin M was administered for 6 weeks. At the end of this antibiotherapy regimen, TTE showed no coronary sinus mass with complete vacuity of the coronary sinus vein and no pericardial effusion.

An alternative explanation for the occurrence of short circuit current increases in the small intestine following challenge by bacterial enterotoxins.

PubMed

Lucas, M L

2013-10-01

Secretory diarrhoeal disease due to enterotoxins is thought to arise from the enhancement to pathologically high rates of normally occurring chloride ion and therefore fluid secretion from enterocytes. In support of this concept, many enterotoxins increase intestinal short-circuit current, regarded now as faithfully reflecting the increased chloride ion secretion. Contradicting this assumption, STa reduces absorption but does not cause secretion in vivo although short-circuit current is increased in vitro. There is therefore a mismatch between an assumed enterocyte mediated secretory event that should but does not cause net fluid secretion and an undoubtedly increased short-circuit current. It is proposed here that short-circuit current increases are not themselves secretory events but result from interrupted fluid absorption. A noteworthy feature of compounds that inhibit the increase in short-circuit current is that the majority are vasoactive, neuroactive or both. In general, vasodilator substances increase current. An alternative hypothesis for the origin of short-circuit current increases is that these result from reflex induction of electrogenic fluid absorption. This reflex enhances a compensatory response that is also present at a cellular level. An intestinal reflex is therefore proposed by which decreases in interstitial and intravascular volume or pressure within the intestine initiate an electrogenic fluid absorption mechanism that compensates for the loss of electrically neutral fluid absorption. This hypothesis would explain the apparently complex pharmacology of short-circuit current increases since many depressor substances have receptors in common with enterocytes and enteric nerves. The proposed alternative view of the origin of short-circuit current increases assumes that these do not represent chloride secretion from the enterocytes. This view may therefore aid the successful development of anti-diarrhoeal drugs to overcome a major cause of infant mortality worldwide, if short-circuit current data are being persistently misinterpreted. The putative but testable link between interstitial volume or pressure and fluid absorption also provides support for the alternative view of secretion; namely, that enhanced capillary and epithelial cell tight junctional permeability together with increased intracapillary pressure may cause secretion and not chloride exit from the enterocytes. Copyright © 2013. Published by Elsevier Ltd.

Test amnioinfusion to determine suitability for serial therapeutic amnioinfusion in midtrimester premature rupture of membranes.

PubMed

Tan, L-K; Kumar, S; Jolly, M; Gleeson, C; Johnson, P; Fisk, N M

2003-01-01

To evaluate whether a test amnioinfusion procedure is useful in selecting cases of midtrimester preterm premature rupture of membranes (PPROM) which may benefit from serial amnioinfusions if the initial fluid is retained. The Centre for Fetal Care database between 1992 and 2000 was reviewed for women with PPROM <26 weeks who had undergone amnioinfusion. Amniotic fluid index (AFI) was assessed before and after a test amnioinfusion procedure. Those who retained fluid > or =48 h underwent serial AFI assessment with a view to serial amnioinfusion when oligohydramnios recurred. Eighty-five amnioinfusion procedures were performed in 60 women with oligohydramnios. Nineteen of these women presented with confirmed PPROM at a median gestation of 19 (range 15-22) weeks and severe olighohydramnios (median AFI 1, range 0-3 cm), in whom 20 test amnioinfusions were carried out. Two amnioinfusions were abandoned during the procedure because of fetal bradycardia and both mothers opted for termination of pregnancy. Only 4 women retained fluid during the test amnioinfusion, 1 of whom miscarried at 19 weeks before serial amnioinfusion could be started. The remaining 3 underwent a median of 4 (range 1-6) serial amnioinfusion procedures; none had evidence of pulmonary hypoplasia. Thirteen (68%) leaked fluid within 48 h; within this group there was 1 subsequent miscarriage and 9 pregnancy terminations. The remaining 3 pregnancies resulted in livebirths 2 of which had pulmonary hypoplasia with 1 early neonatal death. Overall survival was poor (4/19), largely attributed to the high incidence of terminations in the presence of persistent severe oligohydramnios. In continuing pregnancies reaching viability survival was 67% (4 of 6). Three quarters of women with mid-trimester PPROM lose fluid at test amnioinfusion and therefore would not be suitable candidates for serial amnioinfusion. However, if infused fluid is retained, this allows subsequent serial amnioinfusion and prolongation of pregnancy in about 75%, with an attendant decrease in the risk of pulmonary hypoplasia. However, even successful serial amnioinfusion remains associated with procedure-related complications (i.e. chorioamnionitis, placental abruption) which themselves may predispose to preterm delivery. Copyright 2003 S. Karger AG, Basel

Falling, flapping, flying, swimming,...: High-Re fluid-solid interactions with vortex shedding

NASA Astrophysics Data System (ADS)

Michelin, Sebastien Honore Roland

The coupling between the motion of a solid body and the dynamics of the surrounding flow is essential to the understanding of a large number of engineering and physical problems, from the stability of a slender structure exposed to the wind to the locomotion of insects, birds and fishes. Because of the strong coupling on a moving boundary of the equations for the solid and fluid, the simulation of such problems is computationally challenging and expensive. This justifies the development of simplified models for the fluid-solid interactions to study their physical properties and behavior. This dissertation proposes a reduced-order model for the interaction of a sharp-edged solid body with a strongly unsteady high Reynolds number flow. In such a case, viscous forces in the fluid are often negligible compared to the fluid inertia or the pressure forces, and the thin boundary layers separate from the solid at the edges, leading to the shedding of large and persistent vortices in the solid's wake. A general two-dimensional framework is presented based on complex potential flow theory. The formation of the solid's vortical wake is accounted for by the shedding of point vortices with unsteady intensity from the solid's sharp edges, and the fluid-solid problem is reformulated exclusively as a solid-vortex interaction problem. In the case of a rigid solid body, the coupled problem is shown to reduce to a set of non-linear ordinary differential equations. This model is used to study the effect of vortex shedding on the stability of falling objects. The solid-vortex model is then generalized to study the fluttering instability and non-linear flapping dynamics of flexible plates or flags. The uttering instability and resulting flapping motion result from the competing effects of the fluid forcing and of the solid's flexural rigidity and inertia. Finally, the solid-vortex model is applied to the study of the fundamental effect of bending rigidity on the flapping performance of flapping appendages such as insect wings or fish fins.

Symptomatic relevance of intravertebral cleft in patients with osteoporotic vertebral fracture.

PubMed

Kawaguchi, Satoshi; Horigome, Keiko; Yajima, Hideki; Oda, Takashi; Kii, Yuichiro; Ida, Kazunori; Yoshimoto, Mitsunori; Iba, Kousuke; Takebayashi, Tsuneo; Yamashita, Toshihiko

2010-08-01

The present study was designed to determine clinical and radiographic characteristics of unhealed osteoporotic vertebral fractures (OVFs) and the role of fracture mobility and an intravertebral cleft in the regulation of pain symptoms in patients with an OVF. Patients who had persistent low-back pain for 3 months or longer and a collapsed thoracic or lumbar vertebra that had an intervertebral cleft and abnormal mobility were referred to as having unhealed OVFs. Twenty-four patients with an unhealed OVF and 30 patients with an acute OVF were compared with regard to several clinical and radiographic features including the presence of an intravertebral fluid sign. Subsequently, the extent of dynamic mobility of the fractured vertebra was analyzed for correlation with the patients' age, duration of symptoms, back pain visual analog scale (VAS) score, and performance status. Finally, in cases of unhealed OVFs, the subgroup of patients with positive fluid signs was compared with the subgroup of patients with negative fluid signs. Patients with an unhealed OVF were more likely to have a crush-type fracture, shorter vertebral height of the fractured vertebra, and a fracture with a positive fluid sign than those with an acute OVF. The extent of dynamic mobility of the vertebra correlated significantly with the VAS score in patients with an unhealed OVF. In addition, a significant correlation with the extent of dynamic vertebral mobility with performance status was seen in patients with an unhealed OVF and those with an acute OVF. Of the 24 patients with an unhealed OVF, 14 had a positive fluid sign in the affected vertebra. Patients with a positive fluid sign exhibited a statistically significantly greater extent of dynamic vertebral mobility, a higher VAS score, a higher performance status grade, and a greater likelihood of having a crush-type fracture than those with a negative fluid sign. All but 1 patient with an unhealed OVF and a positive fluid sign had an Eastern Cooperative Oncology Group Performance Status Grade 3 or 4 (bedridden most or all of the time). In sharp contrast, all 10 patients with an unhealed OVF and a negative fluid sign were Grade 1 or 2. Unhealed OVFs form a group of fractures that are distinct from acute OVFs regarding radiographic morphometry and contents of the intravertebral cleft. Dynamic vertebral mobility serves as a primal pain determinant in patients with an unhealed OVF and potentially in those with an acute OVF. Fluid accumulation in the intravertebral cleft of unhealed OVFs likely reflects long-term bedridden positioning of the patients in daily activity.

Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water.

PubMed

Wolfe, Marlene K; Gallandat, Karin; Daniels, Kyle; Desmarais, Anne Marie; Scheinman, Pamela; Lantagne, Daniele

2017-01-01

To prevent Ebola transmission, frequent handwashing is recommended in Ebola Treatment Units and communities. However, little is known about which handwashing protocol is most efficacious. We evaluated six handwashing protocols (soap and water, alcohol-based hand sanitizer (ABHS), and 0.05% sodium dichloroisocyanurate, high-test hypochlorite, and stabilized and non-stabilized sodium hypochlorite solutions) for 1) efficacy of handwashing on the removal and inactivation of non-pathogenic model organisms and, 2) persistence of organisms in rinse water. Model organisms E. coli and bacteriophage Phi6 were used to evaluate handwashing with and without organic load added to simulate bodily fluids. Hands were inoculated with test organisms, washed, and rinsed using a glove juice method to retrieve remaining organisms. Impact was estimated by comparing the log reduction in organisms after handwashing to the log reduction without handwashing. Rinse water was collected to test for persistence of organisms. Handwashing resulted in a 1.94-3.01 log reduction in E. coli concentration without, and 2.18-3.34 with, soil load; and a 2.44-3.06 log reduction in Phi6 without, and 2.71-3.69 with, soil load. HTH performed most consistently well, with significantly greater log reductions than other handwashing protocols in three models. However, the magnitude of handwashing efficacy differences was small, suggesting protocols are similarly efficacious. Rinse water demonstrated a 0.28-4.77 log reduction in remaining E. coli without, and 0.21-4.49 with, soil load and a 1.26-2.02 log reduction in Phi6 without, and 1.30-2.20 with, soil load. Chlorine resulted in significantly less persistence of E. coli in both conditions and Phi6 without soil load in rinse water (p<0.001). Thus, chlorine-based methods may offer a benefit of reducing persistence in rinse water. We recommend responders use the most practical handwashing method to ensure hand hygiene in Ebola contexts, considering the potential benefit of chlorine-based methods in rinse water persistence.

Changes in in vitro gas and methane production from rumen fluid from dairy cows during adaptation to feed additives in vivo.

PubMed

Klop, G; van Laar-van Schuppen, S; Pellikaan, W F; Hendriks, W H; Bannink, A; Dijkstra, J

2017-04-01

The adaptation of dairy cows to methane (CH4)-mitigating feed additives was evaluated using the in vitro gas production (GP) technique. Nine rumen-fistulated lactating Holstein cows were grouped into three blocks and within blocks randomly assigned to one of three experimental diets: Control (CON; no feed additive), Agolin Ruminant® (AR; 0.05 g/kg dry matter (DM)) or lauric acid (LA; 30 g/kg DM). Total mixed rations composed of maize silage, grass silage and concentrate were fed in a 40 : 30 : 30 ratio on DM basis. Rumen fluid was collected from each cow at days -4, 1, 4, 8, 15 and 22 relative to the introduction of the additives in the diets. On each of these days, a 48-h GP experiment was performed in which rumen fluid from each individual donor cow was incubated with each of the three substrates that reflected the treatment diets offered to the cows. DM intake was on average 19.8, 20.1 and 16.2 kg/day with an average fat- and protein-corrected milk production of 30.7, 31.7 and 26.2 kg/day with diet CON, AR and LA, respectively. In general, feed additives in the donor cow diet had a larger effect on gas and CH4 production than the same additives in the incubation substrate. Incubation substrate affected asymptotic GP, half-time of asymptotic CH4 production, total volatile fatty acid (VFA) concentration, molar proportions of propionate and butyrate and degradation of organic matter (OMD), but did not affect CH4 production. No substrate×day interactions were observed. A significant diet×day interaction was observed for in vitro gas and CH4 production, total VFA concentration, molar proportions of VFA and OMD. From day 4 onwards, the LA diet persistently reduced gas and CH4 production, total VFA concentration, acetate molar proportion and OMD, and increased propionate molar proportion. In vitro CH4 production was reduced by the AR diet on day 8, but not on days 15 and 22. In line with these findings, the molar proportion of propionate in fermentation fluid was greater, and that of acetate smaller, for the AR diet than for the CON diet on day 8, but not on days 15 and 22. Overall, the data indicate a short-term effect of AR on CH4 production, whereas the CH4-mitigating effect of LA persisted.

Seismic and infrasonic source processes in volcanic fluid systems

NASA Astrophysics Data System (ADS)

Matoza, Robin S.

Volcanoes exhibit a spectacular diversity in fluid oscillation processes, which lead to distinct seismic and acoustic signals in the solid earth and atmosphere. Volcano seismic waveforms contain rich information on the geometry of fluid migration, resonance effects, and transient and sustained pressure oscillations resulting from unsteady flow through subsurface cracks, fissures and conduits. Volcanic sounds contain information on shallow fluid flow, resonance in near-surface cavities, and degassing dynamics into the atmosphere. Since volcanoes have large spatial scales, the vast majority of their radiated atmospheric acoustic energy is infrasonic (<20 Hz). This dissertation presents observations from joint broadband seismic and infrasound array deployments at Mount St. Helens (MSH, Washington State, USA), Tungurahua (Ecuador), and Kilauea Volcano (Hawaii, USA), each providing data for several years. These volcanoes represent a broad spectrum of eruption styles ranging from hawaiian to plinian in nature. The catalogue of recorded infrasonic signals includes continuous broadband and harmonic tremor from persistent degassing at basaltic lava vents and tubes at Pu'u O'o (Kilauea), thousands of repetitive impulsive signals associated with seismic longperiod (0.5-5 Hz) events and the dynamics of the shallow hydrothermal system at MSH, rockfall signals from the unstable dacite dome at MSH, energetic explosion blast waves and gliding infrasonic harmonic tremor at Tungurahua volcano, and large-amplitude and long-duration broadband signals associated with jetting during vulcanian, subplinian and plinian eruptions at MSH and Tungurahua. We develop models for a selection of these infrasonic signals. For infrasonic long-period (LP) events at MSH, we investigate seismic-acoustic coupling from various buried source configurations as a means to excite infrasound waves in the atmosphere. We find that linear elastic seismic-acoustic transmission from the ground to atmosphere is inadequate to explain the observations, and propose that the signals may result from sudden containment failure of a pressurized hydrothermal crack. For the broadband eruption tremor signals, we propose that the infrasonic signals represent a low-frequency form of jet noise, analogous to the noise from man-made jet engines, but operating with larger spatial scales and consequently longer time-scales. For the persistent hawaiian tremor signals, we propose that bubble cloud oscillation in the upper section of a roiling magma conduit and vortex dynamics in the shallow degassing region act as broadband and harmonic tremor sources. We also consider infrasound propagation effects in a dynamic atmosphere and discuss their effects on recorded signals. This dissertation demonstrates that combined seismic and infrasonic data provide complementary perspectives on eruptive activity.

Induction of interferon-gamma and downstream pathways during establishment of fetal persistent infection with bovine viral diarrhea virus.

PubMed

Smirnova, Natalia P; Webb, Brett T; McGill, Jodi L; Schaut, Robert G; Bielefeldt-Ohmann, Helle; Van Campen, Hana; Sacco, Randy E; Hansen, Thomas R

2014-04-01

Development of transplacental infection depends on the ability of the virus to cross the placenta and replicate within the fetus while counteracting maternal and fetal immune responses. Unfortunately, little is known about this complex process. Non-cytopathic (ncp) strains of bovine viral diarrhea virus (BVDV), a pestivirus in the Flaviviridae family, cause persistent infection in early gestational fetuses (<150 days; persistently infected, PI), but are cleared by immunocompetent animals and late gestational fetuses (>150 days; transiently infected, TI). Evasion of innate immune response and development of immunotolerance to ncp BVDV have been suggested as possible mechanisms for the establishment of the persistent infection. Previously we have observed a robust temporal induction of interferon (IFN) type I (innate immune response) and upregulation of IFN stimulated genes (ISGs) in BVDV TI fetuses. Modest chronic upregulation of ISGs in PI fetuses and calves reflects a stimulated innate immune response during persistent BVDV infection. We hypothesized that establishing persistent fetal BVDV infection is also accompanied by the induction of IFN-gamma (IFN-γ). The aims of the present study were to determine IFN-γ concentration in blood and amniotic fluid from control, TI and PI fetuses during BVDV infection and analyze induction of the IFN-γ downstream pathways in fetal lymphoid tissues. Two experiments with in vivo BVDV infections were completed. In Experiment 1, pregnant heifers were infected with ncp BVDV type 2 on day 75 or 175 of gestation or kept naïve to generate PI, TI and control fetuses, respectively. Fetuses were collected by Cesarean section on day 190. In Experiment 2, fetuses were collected on days 82, 89, 97, 192 and 245 following infection of pregnant heifers on day 75 of gestation. The results were consistent with the hypothesis that ncp BVDV infection induces IFN-γ secretion during acute infection in both TI and PI fetuses and that lymphoid tissues such as spleen, liver and thymus, serve both as possible sources of IFN-γ and target organs for its effects. Notably, induction of IFN-γ coincides with a decrease in BVDV RNA concentrations in PI fetal blood and tissues. This is the first report indicating the possible presence of an adaptive immune response in persistent BVDV infections, which may be contributing to the observed reduction of viremia in PI fetuses. Copyright © 2014 Elsevier B.V. All rights reserved.

Selective lesion of septal cholinergic neurons in rats impairs acquisition of a delayed matching to position T-maze task by delaying the shift from a response to a place strategy.

PubMed

Fitz, Nicholas F; Gibbs, Robert B; Johnson, David A

2008-12-16

This study tested the hypothesis that septal cholinergic lesions impair acquisition of a delayed matching to position (DMP) T-maze task in male rats by affecting learning strategy. Rats received either the selective cholinergic immunotoxin, 192 IgG-saporin (SAP) or artificial cerebrospinal fluid directly into the medial septum. Two weeks later, animals were trained to acquire the DMP task. SAP-treated rats took significantly longer to acquire the task than corresponding controls. Both SAP-treated and control rats adopted a persistent turn and utilized a response strategy during early periods of training. By the time rats reached criterion the persistent turn was no longer evident, and all rats had shifted to an allocentric strategy, i.e., were relying on extramaze cues to a significant degree. During the acquisition period, SAP-treated rats spent significantly more days showing a persistent turn and using a response strategy than corresponding controls. The added time spent using a response strategy accounted entirely for the added days required to reach criterion among the SAP-treated rats. This suggests that the principal mechanism by which septal cholinergic lesions impair DMP acquisition in male rats is by increasing the predisposition to use a response vs. a place strategy, thereby affecting the ability to switch from one strategy to another.

Enhanced Amendment Delivery to Subsurface Using Shear Thinning Fluid and Aqueous Foam for Metal, Radionuclide, and NAPL Remediation

NASA Astrophysics Data System (ADS)

Zhong, L.; Szecsody, J.; Li, X.; Oostrom, M.; Truex, M.

2010-12-01

In many contamination sites, removal of contaminants by any active remediation efforts is not practical due to the high cost and technological limitations. Alternatively, in situ remediation is expected to be the most important remediation strategy. Delivery of reactive amendment to the contamination zone is essential for the reactions between the contaminants and remedial amendments to proceed in situ. It is a challenge to effectively deliver remedial amendment to the subsurface contamination source areas in both aquifer and vadose zone. In aquifer, heterogeneity induces fluid bypassing the low-permeability zones, resulting in certain contaminated areas inaccessible to the remedial amendment delivered by water injection, thus inhibiting the success of remedial operations. In vadose zone in situ remediation, conventional solution injection and infiltration for amendment delivery have difficulties to achieve successful lateral spreading and uniform distribution of the reactive media. These approaches also tend to displace highly mobile metal and radionuclide contaminants such as hexavalent chromium [Cr(VI)] and technetium (Tc-99), causing spreading of contaminations. Shear thinning fluid and aqueous foam can be applied to enhance the amendment delivery and improve in situ subsurface remediation efficiency under aquifer and vadose zone conditions, respectively. Column and 2-D flow cell experiments were conducted to demonstrate the enhanced delivery and improved remediation achieved by the application of shear thinning fluid and foam injection at the laboratory scale. Solutions of biopolymer xanthan gum were used as the shear thinning delivering fluids. Surfactant sodium lauryl ether sulfate (STEOL CS-330) was the foaming agent. The shear thinning fluid delivery (STFD) considerably improved the sweeping efficiency over a heterogeneous system and enhanced the non-aqueous liquid phase (NAPL) removal. The delivery of amendment into low-perm zones (LPZs) by STFD also increased the persistence of amendment solution in the LPZs after injection. Immobilization of Tc-99 was improved when a reductant was delivered by foam versus by water-based solution to contaminated vadose zone sediments. Foam delivery remarkably improved the lateral distribution of fluids compared to direct liquid injection. In heterogeneous vadose zone formation, foam injection increased the liquid flow in the high permeable zones into which very limited fluid was distributed during liquid infiltration, demonstrating improved amendment distribution uniformity in the heterogeneous system by foam delivery.

Fluid dynamics vascular theory of brain and inner-ear function in traumatic brain injury: a translational hypothesis for diagnosis and treatment.

PubMed

Shulman, Abraham; Strashun, Arnold M

2009-01-01

It is hypothesized that in all traumatic brain injury (TBI) patients with a clinical history of closed or penetrating head injury, the initial head trauma is associated with a vibratory sensation and noise exposure, with resultant alteration in vascular supply to the structures and contents of the fluid compartments of brain and ear (i.e., the fluid dynamics vascular theory of brain-inner-ear function [FDVTBE]). The primary etiology-head trauma-results in an initial fluctuation, interference, or interaction in the normal fluid dynamics between brain and labyrinth of the inner ear, with a resultant clinical diversity of complaints varying in time of onset and severity. Normal function of the brain and ear is a reflection of a normal state of homeostasis between the fluid compartments in the brain of cerebrospinal fluid and perilymph-endolymph in the labyrinth of the ear. The normal homeostasis in the structures and contents between the two fluid compartment systems--intracerebral and intralabyrinthine--is controlled by mechanisms involved in the maintenance of normal pressures, water and electrolyte content, and neurotransmitter activities. The initial pathophysiology (a reflection of an alteration in the vascular supply to the brain-ear) is hypothesized to be an initial acute inflammatory response, persistence of which results in ischemia and an irreversible alteration in the involved neural substrates of brain-ear. Clinically, a chronic multisymptom complex becomes manifest. The multisymptom complex, individual for each TBI patient regardless of the diagnostic TBI category (i.e., mild, moderate, or severe), initially reflects processes of inflammation and ischemia which, in brain, result in brain volume loss identified as neurodegeneration and hydrocephalus ex vacuo or an alteration in cerebrospinal fluid production (i.e., pseudotumor cerebri) and, in ear, secondary endolymphatic hydrops with associated cochleovestibular complaints of hearing loss, tinnitus, vertigo, ear blockage, and hyperacusis. The FDVTBE integrates and translates a neurovascular hypothesis for Alzheimer's disease to TBI. This study presents an FDVTBE hypothesis of TBI to explain the clinical association of head trauma (TBI) and central nervous system neurodegeneration with multisensory complaints, highlighted by and focusing on cochleovestibular complaints. A clinical case report, previously published for demonstration of the cerebrovascular medical significance of a particular type of tinnitus, and evidence-based basic science and clinical medicine are cited to provide objective evidence in support and demonstration of the FDVTBE.

Macular morphology and visual acuity in the comparison of age-related macular degeneration treatments trials.

PubMed

Jaffe, Glenn J; Martin, Daniel F; Toth, Cynthia A; Daniel, Ebenezer; Maguire, Maureen G; Ying, Gui-Shuang; Grunwald, Juan E; Huang, Jiayan

2013-09-01

To describe the effects of treatment for 1 year with ranibizumab or bevacizumab on macular morphology and the association of macular morphology with visual acuity (VA) in eyes with neovascular age-related macular degeneration (AMD). Prospective cohort study within a randomized clinical trial. Participants in the Comparison of Age-related Macular Degeneration Treatments Trials. Participants were assigned randomly to treatment with ranibizumab or bevacizumab on a monthly or as-needed schedule. Optical coherence tomography (OCT), fluorescein angiography (FA), color fundus photography (FP), and VA testing were performed periodically throughout 52 weeks. Masked readers graded images. General linear models were applied to evaluate effects of time and treatment on outcomes. Fluid type and location and thickness by OCT, size, and lesion composition on FP, FA, and VA. Intraretinal fluid (IRF), subretinal fluid (SRF), subretinal pigment epithelium fluid, and retinal, subretinal, and subretinal tissue complex thickness decreased in all treatment groups. A higher proportion of eyes treated monthly with ranibizumab had fluid resolution at 4 weeks, and the difference persisted through 52 weeks. At 52 weeks, there was little association between the presence of fluid of any type (without regard to fluid location) and the mean VA. However, at all time points, eyes with residual IRF, especially foveal IRF, had worse mean VA (9 letters) than those without IRF. Eyes with abnormally thin (<120 μm) or thick (>212 μm) retinas had worse VA than those with normal thickness (120-212 μm). At week 52, eyes with larger neovascular lesions or with foveal scar had worse VA than eyes without these features. Anti-vascular endothelial growth factor (VEGF) therapy reduced lesion activity and improved VA in all treatment groups. At all time points, eyes with residual IRF had worse VA than those without. Eyes with abnormally thin or thick retinas, residual large lesions, and scar also had worse VA. Monthly ranibizumab dosing yielded more eyes with no fluid and an abnormally thin retina, although the long-term significance is unknown. These results have important treatment implications in eyes undergoing anti-VEGF therapy for neovascular AMD. Proprietary or commercial disclosure may be found after the references. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Absence of Cerebrospinal Fluid Signs of Neuronal Injury Before and After Immediate Antiretroviral Therapy in Acute HIV Infection

PubMed Central

Peluso, Michael J.; Valcour, Victor; Ananworanich, Jintanat; Sithinamsuwan, Pasiri; Chalermchai, Thep; Fletcher, James L. K.; Lerdlum, Sukalya; Chomchey, Nitiya; Slike, Bonnie; Sailasuta, Napapon; Gisslén, Magnus; Zetterberg, Henrik; Spudich, Serena

2015-01-01

Background. It is unknown whether neuronal injury begins during acute human immunodeficiency virus (HIV) infection, and whether immediate initiation of combination antiretroviral therapy (cART) prevents neuronal injury. Methods. Cerebrospinal fluid (CSF) neurofilament light chain (NFL), a measure of axonal injury, was assessed before and after cART initiation in individuals starting treatment during acute or chronic HIV infection. Nonparametric statistics examined relationships between NFL and disease progression, neuroinflammation, and cognitive performance. Results. Before treatment, subjects with acute infection had lower CSF NFL levels, with elevations for their age in 1 of 32 subjects with acute infection (3.1%) and 10 of 32 with chronic infection (31%) (P = .006). This persisted after cART initiation, with 1 of 25 acute (4%) and 4 of 9 chronic subjects (44%) showing elevated NFL levels (P = .01). In acute infection, pre-cART NFL levels were inversely correlated with proton magnetic resonance spectroscopic findings of N-acetylaspartate/creatine in frontal gray matter (r = −0.40; P = .03), frontal white matter (r = −0.46; P = .01), and parietal gray matter (r = −0.47; P = .01); correlations persisted after treatment in the frontal white matter (r = −0.51; P = .02) and parietal gray matter (r = −0.46; P = .04). Conclusions. CSF NFL levels are not elevated in untreated acute HIV infection or after 6 months of immediately initiated cART but are abnormal in chronic HIV infection before and after treatment. In acute HIV infection, CSF NFL levels are inversely associated with neuroimaging markers of neuronal health. PMID:25995196

Pulmonary toxicity of a coal liquefaction distillate product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haschek, W.M.; Boling, M.E.; Guerin, M.R.

1979-01-01

The pulmonary toxicity of coal derived liquids are under study. Results on a sample from the ZnCl/sub 2/ hydrocracking process are presented as an example. We obtained data on its distribution and persistence in the lung as well as the tissue reaction elicited. We also examined individual chemical fractions to determine which was responsible for pulmonary toxicity. Fifty ..mu..l of the distillate or fraction was administered intratracheally to adult male SPF Fisher rats which were then killed at varying time-points, ranging from 1 to 60 days after administration. Enzyme analysis of pulmonary lavage fluid, /sup 3/H-thymidine incorporation into pulmonary DNA,more » autoradiography, light and fluorescence microscopy were performed. At necropsy the distillate, a black viscid fluid, could be seen within major airways in some lobes. Extensive consolidation and atelectasis or, less frequently, overinflation was present in affected lobes. Twenty-four hours after administration the distillate remained visible in large and small airways as well as in the adjacent parenchyma producing a suppurative necrotizing bronchiolitis and pneumonitis. Within 4 days a histiocytic-fibroblastic reaction to the distillate resulted in granulomatous lesions in the parenchyma, as well as polypoid hyperplasia and obliterating bronchiolitis in the severely damaged airways. Extensive epithelial changes consisting of goblet and columnar cell hyperplasia, as well as squamous metaplasia with focal dysplasia were present throughout the respiratory tract at this time. Similar lesions were produced by the ether-soluble acid fraction, while the mono- and di-aromatic fraction produced less severe lesions which were localized to the airways. After 60 days the product distillate, primarily localized within granulomas, still persisted within the lung as visualized by fluorescence microscopy. Mucoid bronchiolitis with scattered polypoid hyperplasia, as well as epithelial hyperplasia and metaplasia were also present.« less

Cerebrospinal fluid neopterin: an informative biomarker of central nervous system immune activation in HIV-1 infection.

PubMed

Hagberg, Lars; Cinque, Paola; Gisslen, Magnus; Brew, Bruce J; Spudich, Serena; Bestetti, Arabella; Price, Richard W; Fuchs, Dietmar

2010-06-03

HIV-1 invades the central nervous system (CNS) in the context of acute infection, persists thereafter in the absence of treatment, and leads to chronic intrathecal immunoactivation that can be measured by the macrophage activation marker, neopterin, in cerebrospinal fluid (CSF). In this review we describe our experience with CSF neopterin measurements in 382 untreated HIV-infected patients across the spectrum of immunosuppression and HIV-related neurological diseases, in 73 untreated AIDS patients with opportunistic CNS infections, and in 233 treated patients.In untreated patients, CSF neopterin concentrations are almost always elevated and increase progressively as immunosuppression worsens and blood CD4 cell counts fall. However, patients with HIV dementia exhibit particularly high CSF neopterin concentrations, above those of patients without neurological disease, though patients with CNS opportunistic infections, including CMV encephalitis and cryptococcal meningitis, also exhibit high levels of CSF neopterin. Combination antiretroviral therapy, with its potent effect on CNS HIV infection and CSF HIV RNA, mitigates both intrathecal immunoactivation and lowers CSF neopterin. However, despite suppression of plasma and CSF HIV RNA to below the detection limits of clinical assays (<50 copies HIV RNA/mL), CSF neopterin often remains mildly elevated, indicating persistent low-level intrathecal immune activation and raising the important questions of whether this elevation is driven by continued CNS infection and whether it causes continued indolent CNS injury.Although nonspecific, CSF neopterin can serve as a useful biomarker in the diagnosis of HIV dementia in the setting of confounding conditions, in monitoring the CNS inflammatory effects of antiretroviral treatment, and give valuable information to the cause of ongoing brain injury.

Absence of Cerebrospinal Fluid Signs of Neuronal Injury Before and After Immediate Antiretroviral Therapy in Acute HIV Infection.

PubMed

Peluso, Michael J; Valcour, Victor; Ananworanich, Jintanat; Sithinamsuwan, Pasiri; Chalermchai, Thep; Fletcher, James L K; Lerdlum, Sukalya; Chomchey, Nitiya; Slike, Bonnie; Sailasuta, Napapon; Gisslén, Magnus; Zetterberg, Henrik; Spudich, Serena

2015-12-01

It is unknown whether neuronal injury begins during acute human immunodeficiency virus (HIV) infection, and whether immediate initiation of combination antiretroviral therapy (cART) prevents neuronal injury. Cerebrospinal fluid (CSF) neurofilament light chain (NFL), a measure of axonal injury, was assessed before and after cART initiation in individuals starting treatment during acute or chronic HIV infection. Nonparametric statistics examined relationships between NFL and disease progression, neuroinflammation, and cognitive performance. Before treatment, subjects with acute infection had lower CSF NFL levels, with elevations for their age in 1 of 32 subjects with acute infection (3.1%) and 10 of 32 with chronic infection (31%) (P = .006). This persisted after cART initiation, with 1 of 25 acute (4%) and 4 of 9 chronic subjects (44%) showing elevated NFL levels (P = .01). In acute infection, pre-cART NFL levels were inversely correlated with proton magnetic resonance spectroscopic findings of N-acetylaspartate/creatine in frontal gray matter (r = -0.40; P = .03), frontal white matter (r = -0.46; P = .01), and parietal gray matter (r = -0.47; P = .01); correlations persisted after treatment in the frontal white matter (r = -0.51; P = .02) and parietal gray matter (r = -0.46; P = .04). CSF NFL levels are not elevated in untreated acute HIV infection or after 6 months of immediately initiated cART but are abnormal in chronic HIV infection before and after treatment. In acute HIV infection, CSF NFL levels are inversely associated with neuroimaging markers of neuronal health. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Trans aqueductal, third ventricle - Cervical subarachnoid stenting: An adjuvant cerebro spinal fluid diversion procedure in midline posterior fossa tumors with hydrocephalus: The technical note and case series.

PubMed

Teegala, Ramesh

2016-01-01

Persistent or progressive hydrocephalus is one of the complex problems of posterior fossa tumors associated with hydrocephalus. The author evaluated the effectiveness of single-stage tumor decompression associated with a stent technique (trans aqueductal third ventricle - Cervical subarachnoid stenting) as an adjuvant cerebro spinal fluid (CSF) diversion procedure in controlling the midline posterior fossa tumors with hydrocephalus. Prospective clinical case series of 15 patients was evaluated from July 2006 to April 2012. Fifteen clinicoradiological diagnosed cases of midline posterior fossa tumors with hydrocephalus were included in this study. All the tumors were approached through the cerebello medullary (telo velo tonsilar) fissure technique. Following the excision of the posterior fossa tumor, a sizable stent was placed across the aqueduct from the third ventricle to the cervical subarachnoid space. There were nine male and six female patients with an average age of 23 years. Complete tumor excision could be achieved in 12 patients and subtotal excision with clearance of aqueduct in remaining three patients. Hydrocephalus was controlled effectively in all the patients. There were no stent-related complications. This study showed the reliability of single-stage tumor excision followed by placement of aqueductal stent. The success rate of this technique is comparable to those of conventional CSF diversion procedures. This is a simple, safe, and effective procedure for the management of persistent and or progressive hydrocephalus. This technique may be very useful in situations where the patient's follow-up is compromised and the patients who are from a poor economic background. Long-term results need further evaluation to assess the overall functioning of this stent technique.

Scaling for turbulent viscosity of buoyant plumes in stratified fluids: PIV measurement with implications for submarine hydrothermal plume turbulence

NASA Astrophysics Data System (ADS)

Zhang, Wei; He, Zhiguo; Jiang, Houshuo

2017-11-01

Time-resolved particle image velocimetry (PIV) has been used to measure instantaneous two-dimensional velocity vector fields of laboratory-generated turbulent buoyant plumes in linearly stratified saltwater over extended periods of time. From PIV-measured time-series flow data, characteristics of plume mean flow and turbulence have been quantified. To be specific, maximum plume penetration scaling and entrainment coefficient determined from the mean flow agree well with the theory based on the entrainment hypothesis for buoyant plumes in stratified fluids. Besides the well-known persistent entrainment along the plume stem (i.e., the 'plume-stem' entrainment), the mean plume velocity field shows persistent entrainment along the outer edge of the plume cap (i.e., the 'plume-cap' entrainment), thereby confirming predictions from previous numerical simulation studies. To our knowledge, the present PIV investigation provides the first measured flow field data in the plume cap region. As to measured plume turbulence, both the turbulent kinetic energy field and the turbulence dissipation rate field attain their maximum close to the source, while the turbulent viscosity field reaches its maximum within the plume cap region; the results also show that maximum turbulent viscosity scales as νt,max = 0.030(B/N)1/2, where B is source buoyancy flux and N is ambient buoyancy frequency. These PIV data combined with previously published numerical simulation results have implications for understanding the roles of hydrothermal plume turbulence, i.e. plume turbulence within the cap region causes the 'plume-cap' entrainment that plays an equally important role as the 'plume-stem' entrainment in supplying the final volume flux at the plume spreading level.

Fluid mechanics of human fetal right ventricles from image-based computational fluid dynamics using 4D clinical ultrasound scans.

PubMed

Wiputra, Hadi; Lai, Chang Quan; Lim, Guat Ling; Heng, Joel Jia Wei; Guo, Lan; Soomar, Sanah Merchant; Leo, Hwa Liang; Biwas, Arijit; Mattar, Citra Nurfarah Zaini; Yap, Choon Hwai

2016-12-01

There are 0.6-1.9% of US children who were born with congenital heart malformations. Clinical and animal studies suggest that abnormal blood flow forces might play a role in causing these malformation, highlighting the importance of understanding the fetal cardiovascular fluid mechanics. We performed computational fluid dynamics simulations of the right ventricles, based on four-dimensional ultrasound scans of three 20-wk-old normal human fetuses, to characterize their flow and energy dynamics. Peak intraventricular pressure gradients were found to be 0.2-0.9 mmHg during systole, and 0.1-0.2 mmHg during diastole. Diastolic wall shear stresses were found to be around 1 Pa, which could elevate to 2-4 Pa during systole in the outflow tract. Fetal right ventricles have complex flow patterns featuring two interacting diastolic vortex rings, formed during diastolic E wave and A wave. These rings persisted through the end of systole and elevated wall shear stresses in their proximity. They were observed to conserve ∼25.0% of peak diastolic kinetic energy to be carried over into the subsequent systole. However, this carried-over kinetic energy did not significantly alter the work done by the heart for ejection. Thus, while diastolic vortexes played a significant role in determining spatial patterns and magnitudes of diastolic wall shear stresses, they did not have significant influence on systolic ejection. Our results can serve as a baseline for future comparison with diseased hearts. Copyright © 2016 the American Physiological Society.

Microstructures of Randall's plaques and their interfaces with calcium oxalate monohydrate kidney stones reflect underlying mineral precipitation mechanisms.

PubMed

Sethmann, Ingo; Wendt-Nordahl, Gunnar; Knoll, Thomas; Enzmann, Frieder; Simon, Ludwig; Kleebe, Hans-Joachim

2017-06-01

Randall's plaques (RP) are preferred sites for the formation of calcium oxalate monohydrate (COM) kidney stones. However, although processes of interstitial calcium phosphate (CaP) plaque formation are not well understood, the potential of plaque microstructures as indicators of CaP precipitation conditions received only limited attention. We investigated RP-associated COM stones for structural details of the calcified tissues and microstructural features of plaque-stone interfaces as indicators of the initial processes of stone formation. Significantly increased CaP supersaturation can be expected for interstitial fluid, if reabsorbed ions from the tubular system continuously diffuse into the collagenous connective tissue. Densely packed, fine-grained CaP particles were found in dense textures of basement membranes while larger, laminated particles were scattered in coarse-meshed interstitial tissue, which we propose to be due to differential spatial confinements and restrictions of ion diffusion. Particle morphologies suggest an initial precipitation as metastable amorphous calcium phosphate (ACP). Morphologies and arrangements of first COM crystals at the RP-stone interface ranged from stacked euhedral platelets to skeletal morphologies and even porous, dendritic structures, indicating, in this order, increasing levels of COM supersaturation. Furthermore, these first COM crystals were often coated with CaP. On this basis, we propose that ions from CaP-supersaturated interstitial fluid may diffuse through porous RP into the urine, where a resulting local increase in COM supersaturation could trigger crystal nucleation and, hence, initiate stone formation. Ion-depleted fluid in persistent pores of initial COM layers may get replenished from interstitial fluid, leading to CaP precipitation in porous COM.

Clinical manifestations of optic pit maculopathy as demonstrated by spectral domain optical coherence tomography.

PubMed

Tzu, Jonathan H; Flynn, Harry W; Berrocal, Audina M; Smiddy, William E; Murray, Timothy G; Fisher, Yale L

2013-01-01

The purpose of this retrospective study was to evaluate the characteristic features, including spectral-domain optical coherence tomography (SD-OCT), clinical course, and outcome of treatment if given for patients with optic disc pit maculopathy. We investigated a consecutive series of patients with a diagnosis of optic pit maculopathy treated between 2001 and 2012 at the Bascom Palmer Eye Institute. Patients were divided into two main groups, ie, patients who were observed without surgery and patients who received surgical intervention. The main outcome measures were presenting and final visual acuity, and changes in SD-OCT imaging were recorded. Other data including age, gender, eye, age of onset, length of follow-up, location of optic pit, and location of fluid by OCT were also recorded. On OCT, 67% (12/18) of the eyes showed schisis-like cavities, 22% (4/18) had only subretinal fluid, and 17% (3/18) had only a schisis-like cavity without subretinal fluid. In the patients managed by observation, visual acuity was ≥20/200 in 6/8 eyes initially and 6/8 eyes at last follow-up. Ten of 18 patients received either focal laser, surgery or both. Six of 10 eyes undergoing surgery had initial visual acuity ≥ 20/200, and 8 of 10 eyes undergoing surgery had a visual acuity of ≥20/200 at last follow-up. In this study, many eyes were observed and remained stable during follow-up. In eyes with reduced vision, surgical intervention produced variable outcomes, and persistent intraretinal/subretinal fluid was a common occurrence.

Persistence of tungsten oxide particle/fiber mixtures in artificial human lung fluids

PubMed Central

2010-01-01

Background During the manufacture of tungsten metal for non-sag wire, tungsten oxide powders are produced as intermediates and can be in the form of tungsten trioxide (WO3) or tungsten blue oxides (TBOs). TBOs contain fiber-shaped tungsten sub-oxide particles of respirable or thoracic size. The aim of this research was to investigate whether fiber-containing TBOs had prolonged biodurability in artificial lung fluids compared to tungsten metal or WO3 and therefore potentially could pose a greater inhalation hazard. Methods Dissolution of tungsten metal, WO3, one fiber-free TBO (WO2.98), and three fiber-containing TBO (WO2.81, WO2.66, and WO2.51) powders were measured for the material as-received, dispersed, and mixed with metallic cobalt. Solubility was evaluated using artificial airway epithelial lining fluid (SUF) and macrophage phagolysosomal simulant fluid (PSF). Results Dissolution rates of tungsten compounds were one to four orders of magnitude slower in PSF compared to SUF. The state of the fiber-containing TBOs did not influence their dissolution in either SUF or PSF. In SUF, fiber-containing WO2.66 and WO2.51 dissolved more slowly than tungsten metal or WO3. In PSF, all three fiber-containing TBOs dissolved more slowly than tungsten metal. Conclusions Fiber-containing TBO powders dissolved more slowly than tungsten metal and WO3 powders in SUF and more slowly than tungsten metal in PSF. Existing pulmonary toxicological information on tungsten compounds indicates potential for pulmonary irritation and possibly fibrosis. Additional research is needed to fully understand the hazard potential of TBOs. PMID:21126345

Nerve growth factor concentrations in the synovial fluid from healthy dogs and dogs with secondary osteoarthritis.

PubMed

Isola, M; Ferrari, V; Miolo, A; Stabile, F; Bernardini, D; Carnier, P; Busetto, R

2011-01-01

To measure the concentrations of nerve growth factor (NGF) in the synovial fluid from normal dogs and dogs with osteoarthritis (OA) secondary to common joint disorders. Nerve growth factor synovial concentrations were measured by ELISA assay in 50 dogs divided into three groups: 12 healthy, 16 affected by acute lameness within seven days before enrolment, and 22 with chronic lameness persisting by more than one month before enrolment and accompanied by radiological signs of OA. Both acute and chronic lameness were secondary to orthopaedic diseases involving the shoulder, elbow and stifle joints. Nerve growth factor synovial concentrations were compared between means for healthy and acute groups and between the three groups using an F-test. Significance level was set at p <0.05. Nerve growth factor was detected in all canine synovial fluid samples. However, the mean synovial NGF concentration of healthy dogs (3.65 ± 2.18 pg/ml) was not significantly different from the mean value in dogs with acute lameness (6.45 ± 2.45 pg/ml) (p = 0.79). Conversely, the mean synovial NGF concentration in dogs with chronic lameness (20.19 ± 17.51 pg/ml) was found to be significantly higher than that found in healthy dogs (p <0.01). This study demonstrates for the first time the presence of NGF in canine synovial fluid and its increased concentrations in dogs with chronic lameness compared to healthy dogs and dogs with acute lameness. The association between chronic lameness and raised synovial concentrations may suggest an involvement of NGF in OA inflammation and chronic pain.

Scrapie Agent (Strain 263K) Can Transmit Disease via the Oral Route after Persistence in Soil over Years

PubMed Central

Groschup, Martin H.; Peters, Rainer; Beekes, Michael; Terytze, Konstantin

2007-01-01

The persistence of infectious biomolecules in soil constitutes a substantial challenge. This holds particularly true with respect to prions, the causative agents of transmissible spongiform encephalopathies (TSEs) such as scrapie, bovine spongiform encephalopathy (BSE), or chronic wasting disease (CWD). Various studies have indicated that prions are able to persist in soil for years without losing their pathogenic activity. Dissemination of prions into the environment can occur from several sources, e.g., infectious placenta or amniotic fluid of sheep. Furthermore, environmental contamination by saliva, excrements or non-sterilized agricultural organic fertilizer is conceivable. Natural transmission of scrapie in the field seems to occur via the alimentary tract in the majority of cases, and scrapie-free sheep flocks can become infected on pastures where outbreaks of scrapie had been observed before. These findings point to a sustained contagion in the environment, and notably the soil. By using outdoor lysimeters, we simulated a contamination of standard soil with hamster-adapted 263K scrapie prions, and analyzed the presence and biological activity of the soil-associated PrPSc and infectivity by Western blotting and hamster bioassay, respectively. Our results showed that 263K scrapie agent can persist in soil at least over 29 months. Strikingly, not only the contaminated soil itself retained high levels of infectivity, as evidenced by oral administration to Syrian hamsters, but also feeding of aqueous soil extracts was able to induce disease in the reporter animals. We could also demonstrate that PrPSc in soil, extracted after 21 months, provides a catalytically active seed in the protein misfolding cyclic amplification (PMCA) reaction. PMCA opens therefore a perspective for considerably improving the detectability of prions in soil samples from the field. PMID:17502917

No evidence of persisting measles virus in peripheral blood mononuclear cells from children with autism spectrum disorder.

PubMed

D'Souza, Yasmin; Fombonne, Eric; Ward, Brian J

2006-10-01

Despite epidemiologic evidence to the contrary, claims of an association between measles-mumps-rubella vaccination and the development of autism have persisted. Such claims are based primarily on the identification of measles virus nucleic acids in tissues and body fluids by polymerase chain reaction. We sought to determine whether measles virus nucleic acids persist in children with autism spectrum disorder compared with control children. Peripheral blood mononuclear cells were isolated from 54 children with autism spectrum disorder and 34 developmentally normal children, and up to 4 real-time polymerase chain reaction assays and 2 nested polymerase chain reaction assays were performed. These assays targeted the nucleoprotein, fusion, and hemagglutinin genes of measles virus using previously published primer pairs with detection by SYBR green I. Our own real-time assay targeted the fusion gene using novel primers and an internal fluorescent probe. Positive reactions were evaluated rigorously, and amplicons were sequenced. Finally, anti-measles antibody titers were measured by enzyme immunoassay. The real-time assays based on previously published primers gave rise to a large number of positive reactions in both autism spectrum disorder and control samples. Almost all of the positive reactions in these assays were eliminated by evaluation of melting curves and amplicon band size. The amplicons for the remaining positive reactions were cloned and sequenced. No sample from either autism spectrum disorder or control groups was found to contain nucleic acids from any measles virus gene. In the nested polymerase chain reaction and in-house assays, none of the samples yielded positive results. Furthermore, there was no difference in anti-measles antibody titers between the autism and control groups. There is no evidence of measles virus persistence in the peripheral blood mononuclear cells of children with autism spectrum disorder.

Influence of Particle Size on Persistence and Clearance of Aerosolized Silver Nanoparticles in the Rat Lung

PubMed Central

Anderson, Donald S.; Patchin, Esther S.; Silva, Rona M.; Uyeminami, Dale L.; Sharmah, Arjun; Guo, Ting; Das, Gautom K.; Brown, Jared M.; Shannahan, Jonathan; Gordon, Terry; Chen, Lung Chi; Pinkerton, Kent E.; Van Winkle, Laura S.

2015-01-01

The growing use of silver nanoparticles (AgNPs) in consumer products raises concerns about potential health effects. This study investigated the persistence and clearance of 2 different size AgNPs (20 and 110 nm) delivered to rats by single nose-only aerosol exposures (6 h) of 7.2 and 5.4 mg/m3, respectively. Rat lung tissue was assessed for silver accumulations using inductively-coupled plasma mass spectrometry (ICP-MS), autometallography, and enhanced dark field microscopy. Involvement of tissue macrophages was assessed by scoring of silver staining in bronchoalveolar lavage fluid (BALF). Silver was abundant in most macrophages at 1 day post-exposure. The group exposed to 20 nm AgNP had the greatest number of silver positive BALF macrophages at 56 days post-exposure. While there was a significant decrease in the amount of silver in lung tissue at 56 days post-exposure compared with 1 day following exposure, at least 33% of the initial delivered dose was still present for both AgNPs. Regardless of particle size, silver was predominantly localized within the terminal bronchial/alveolar duct junction region of the lung associated with extracellular matrix and within epithelial cells. Inhalation of both 20 and 110 nm AgNPs resulted in a persistence of silver in the lung at 56 days post-exposure and local deposition as well as accumulation of silver at the terminal bronchiole alveolar duct junction. Further the smaller particles, 20 nm AgNP, produced a greater silver burden in BALF macrophages as well as greater persistence of silver positive macrophages at later timepoints (21 and 56 days). PMID:25577195

Multi-scale fracture networks within layered shallow water tight carbonates

NASA Astrophysics Data System (ADS)

Panza, Elisa; Agosta, Fabrizio; Rustichelli, Andrea; Vinciguerra, Sergio; Zambrano, Miller; Prosser, Giacomo; Tondi, Emanuele

2015-04-01

The work is aimed at deciphering the contribution of background deformation and persistent fracture zones on the fluid flow properties of tight platform carbonates. Taking advantage of 3D exposures present in the Murge area of southern Italy, the fracture networks crosscutting at different scales the layered Cretaceous limestone of the Altamura Fm. were analyzed. The rock multi-layer is characterized by 10's of cm-thick, sub-horizontal, laterally continuous carbonate beds. Each bed commonly represents a shallowing-upward peritidal cycle made up of homogeneous micritic limestones grading upward to cm-thick stromatolitic limestones and/or fenestral limestones. The bed interfaces are formed by sharp maximum flooding surfaces. Porosity measurements carried out on 40 limestone samples collected from a single carbonate bed show values ranging between 0,5% and 5,5%. Background deformation includes both stratabound and non-stratabound fractures. The former elements consist of bed-perpendicular joints and sheared joints, which are confined within a single bed and often displace small, bed-parallel stylolites. Non-stratabound fractures consist of incipient, cm offset, sub-vertical strike-slip faults, which crosscut the bed interfaces. The aforementioned elements are often confined within individual bed-packages, which are identified by presence of pronounced surfaces locally marked by veneers of reddish clayey paleosoils. Persistent fracture zones consist of 10's of m-high, 10's of cm-offset strike-slip faults that offset the bed-package interfaces and are confined within individual bed-packages association. Laterally discontinuous, cm- to a few m-thick paleokarstic breccia levels separate the different bed-packages associations. Persistent fracture zones include asymmetric fractured damage zones and mm-thick veneers of discontinuous fault rocks. The fracture networks that pervasively crosscut the study limestone multi-layer are investigated by mean of scanline and scanarea methodologies. The dimensional, spatial and scaling properties of both stratabound and non-stratabound fractures are documented along single beds and bed-packages, respectively. Persistent fracture zones are studied from individual bed-package associations. By computing the intensity, height distribution, aspect ratio, aperture of each fracture/fault set, DFN (Discrete Fracture Network) models are built for the aforementioned different scales of observation. DFN models of single beds and bed-packages include stratabound and non-stratabound fractures. Differently, the DFN model of a bed-packages association also includes persistent fracture zones and related damage zones. To check the results of our computations, we also build up a smaller scale, 1m3 geocellular volume in which fractures are inserted one at time in the model. All DFN models do not include the matrix porosity. Porosity and 3D permeability (Kx, Ky, Kz) values are obtained as outputs of the DFN models. The results are consistent with the most prominet set of non-stratabound fractures being the major control on the petrophysical properties of both single beds and bed-packages. As expected, the persistent fractures zones strongly affect both porosity and permeability of the bed-packages association. The results of ongoing laboratory analyses on representative limestone samples not only will provide a quantitative assessment of the physical properties of the matrix in terms of porosity and permeability, but also will shed new light on the geometry, density and anisotropy of microfractures and their role on fluid flow properties.

A New Paradigm for Diagnosing Contributions to Model Aerosol Forcing Error: Diagnosing Model Aerosol Forcing Error

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, A. L.; Feldman, D. R.; Freidenreich, S.

A new paradigm in benchmark absorption-scattering radiative transfer is presented that enables both the globally averaged and spatially resolved testing of climate model radiation parameterizations in order to uncover persistent sources of biases in the aerosol instantaneous radiative effect (IRE). A proof of concept is demonstrated with the Geophysical Fluid Dynamics Laboratory AM4 and Community Earth System Model 1.2.2 climate models. Instead of prescribing atmospheric conditions and aerosols, as in prior intercomparisons, native snapshots of the atmospheric state and aerosol optical properties from the participating models are used as inputs to an accurate radiation solver to uncover model-relevant biases. Thesemore » diagnostic results show that the models' aerosol IRE bias is of the same magnitude as the persistent range cited (~1 W/m 2) and also varies spatially and with intrinsic aerosol optical properties. The findings presented here underscore the significance of native model error analysis and its dispositive ability to diagnose global biases, confirming its fundamental value for the Radiative Forcing Model Intercomparison Project.« less

A New Paradigm for Diagnosing Contributions to Model Aerosol Forcing Error: Diagnosing Model Aerosol Forcing Error

DOE PAGES

Jones, A. L.; Feldman, D. R.; Freidenreich, S.; ...

2017-12-07

A new paradigm in benchmark absorption-scattering radiative transfer is presented that enables both the globally averaged and spatially resolved testing of climate model radiation parameterizations in order to uncover persistent sources of biases in the aerosol instantaneous radiative effect (IRE). A proof of concept is demonstrated with the Geophysical Fluid Dynamics Laboratory AM4 and Community Earth System Model 1.2.2 climate models. Instead of prescribing atmospheric conditions and aerosols, as in prior intercomparisons, native snapshots of the atmospheric state and aerosol optical properties from the participating models are used as inputs to an accurate radiation solver to uncover model-relevant biases. Thesemore » diagnostic results show that the models' aerosol IRE bias is of the same magnitude as the persistent range cited (~1 W/m 2) and also varies spatially and with intrinsic aerosol optical properties. The findings presented here underscore the significance of native model error analysis and its dispositive ability to diagnose global biases, confirming its fundamental value for the Radiative Forcing Model Intercomparison Project.« less

Persistent Pneumocystis colonization leads to the development of chronic obstructive pulmonary disease (COPD) in a non-human primate model of AIDS

PubMed Central

Shipley, Timothy W.; Kling, Heather M.; Morris, Alison; Patil, Sangita; Kristoff, Jan; Guyach, Siobhan E.; Murphy, Jessica M.; Shao, Xiuping; Sciurba, Frank C.; Rogers, Robert M.; Richards, Thomas; Thompson, Paul; Montelaro, Ronald C.; Coxson, Harvey O.; Hogg, James C.; Norris, Karen A.

2010-01-01

HIV-infected patients are at increased risk for development of pulmonary complications, including chronic obstructive pulmonary disease (COPD). Inflammation associated with sub-clinical infection has been postulated to promote COPD. Persistence of Pneumocystis (Pc) is associated with HIV and COPD, although a causal relationship has not been established. We used a simian/human immunodeficiency virus (SHIV) model of HIV infection to study pulmonary effects of Pc colonization. SHIV-infected/Pc-colonized monkeys developed progressive obstructive pulmonary disease characterized by increased emphysematous tissue and bronchial-associated lymphoid tissue. Elevated Th2 cytokines and pro-inflammatory mediators in bronchoalveolar lavage fluid coincided with Pc colonization and pulmonary function decline. These results support the concept that an infectious agent contributes to development of HIV-associated lung disease and suggests that Pc colonization may be a risk factor for the development of HIV-associated COPD. Furthermore, this model allows examination of early host responses important to disease progression thus identifying potential therapeutic targets for COPD. PMID:20533880

5. Diagnosis and Treatment of Lyme Arthritis

PubMed Central

Arvikar, Sheila L.; Steere, Allen C.

2015-01-01

SYNOPSIS In the United States, Lyme arthritis is the most common feature of late stage infection with the tick-borne spirochete, Borrelia burgdorferi, usually beginning months after the initial tick bite. However, in some patients, including most of those seen today, the earlier phases of the infection are asymptomatic and arthritis is the presenting manifestation of the disease. Patients with Lyme arthritis have intermittent or persistent attacks of joint swelling and pain in one or a few large joints, especially the knee, usually over a period of several years, without prominent systemic manifestations. Serologic testing is the mainstay of diagnosis. Synovial fluid PCR testing for B. burgdorferi DNA is often positive prior to treatment, but it is not a reliable marker of spirochetal eradication after antibiotic therapy. Responses to oral or intravenous antibiotic treatment are generally excellent, although a small percentage of patients have persistent synovitis after 2-3 months of oral and IV antibiotics, which usually then responds to anti-inflammatory therapies, disease modifying anti-rheumatic drugs (DMARDs), or synovectomy. This chapter reviews the clinical manifestations, diagnosis, and management of Lyme arthritis. PMID:25999223

New daily persistent headache.

PubMed

Rozen, Todd D

2010-01-01

New daily persistent headache (NDPH) is a unique form of chronic daily headache (CDH) which is marked by a daily headache from onset, typically occurring in individuals without a significant prior history of headaches. There are two subforms of NDPH: one which is self-limited and normally goes away without therapy, and a more chronic refractory form which is unresponsive to typical headache treatment strategies. The pathogenesis of NDPH is unknown but recent observations suggest a connection with cervical spine hypermobility and elevation of proinflammatory cytokines in the cerebrospinal fluid (CSF). Recognized triggers for NDPH include infection, stressful life events, and surgical procedures. Clinically, NDPH is characterized by continuous head pain of mild to severe intensity. Migrainous symptoms are common. The syndrome appears to affect women in their teens and 20s, while males develop NDPH later in life in their 50s or 60s. There are no recognized treatments for this condition, although treatment options will be discussed. Secondary mimics of NDPH will also be touched upon in this chapter. Copyright © 2011 Elsevier B.V. All rights reserved.

Achieving the Middle Ground in an Age of Concentrated Extremes: Mixed Middle-Income Neighborhoods and Emerging Adulthood

PubMed Central

SAMPSON, ROBERT J.; MARE, ROBERT D.; PERKINS, KRISTIN L.

2015-01-01

This article focuses on stability and change in “mixed middle-income” neighborhoods. We first analyze variation across nearly two decades for all neighborhoods in the United States and in the Chicago area, particularly. We then analyze a new longitudinal study of almost 700 Chicago adolescents over an 18-year span, including the extent to which they are exposed to different neighborhood income dynamics during the transition to young adulthood. The concentration of income extremes is persistent among neighborhoods, generally, but mixed middle-income neighborhoods are more fluid. Persistence also dominates among individuals, though Latino-Americans are much more likely than African Americans or whites to be exposed to mixed middle-income neighborhoods in the first place and to transition into them over time, even when adjusting for immigrant status, education, income, and residential mobility. The results here enhance our knowledge of the dynamics of income inequality at the neighborhood level, and the endurance of concentrated extremes suggests that policies seeking to promote mixed-income neighborhoods face greater odds than commonly thought. PMID:26722129

Time-dependent deformation of gas shales - role of rock framework versus reservoir fluids

NASA Astrophysics Data System (ADS)

Hol, Sander; Zoback, Mark

2013-04-01

Hydraulic fracturing operations are generally performed to achieve a fast, drastic increase of permeability and production rates. Although modeling of the underlying short-term mechanical response has proven successful via conventional geomechanical approaches, predicting long-term behavior is still challenging as the formation interacts physically and chemically with the fluids present in-situ. Recent experimental work has shown that shale samples subjected to a change in effective stress deform in a time-dependent manner ("creep"). Although the magnitude and nature of this behavior is strongly related to the composition and texture of the sample, also the choice of fluid used in the experiments affects the total strain response - strongly adsorbing fluids result in more, recoverable creep. The processes underlying time-dependent deformation of shales under in-situ stresses, and the long-term impact on reservoir performance, are at present poorly understood. In this contribution, we report triaxial mechanical tests, and theoretical/thermodynamic modeling work with the aim to identify and describe the main mechanisms that control time-dependent deformation of gas shales. In particular, we focus on the role of the shale solid framework versus the type and pressure of the present pore fluid. Our experiments were mainly performed on Eagle Ford Shale samples. The samples were subjected to cycles of loading and unloading, first in the dry state, and then again after equilibrating them with (adsorbing) CO2 and (non-adsorbing) He at fluid pressures of 4 MPa. Stresses were chosen close to those persisting under in-situ conditions. The results of our tests demonstrate that likely two main types of deformation mechanisms operate that relate to a) the presence of microfractures as a dominating feature in the solid framework of the shale, and b) the adsorbing potential of fluids present in the nanoscale voids of the shale. To explain the role of adsorption in the observed compaction creep, we postulate a serial coupling between 1) stress-driven desorption of the fluid species, 2) diffusion of the desorbed species out of the solid, and 3) consequent shrinkage. We propose a model in which the total shrinkage of the solid (Step 3) that is measured as bulk compaction, is driven by a change in stress state (Step 1), and evolves in time controlled by the diffusion characteristics of the system (Step 2). Our experimental and modeling study shows that both the nature of the solid framework of the shale, as well as the type and pressure of pore fluids affect the long-term in-situ mechanical behavior of gas shale reservoirs.

Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Columbia River Basin

USGS Publications Warehouse

Hinck, Jo Ellen; Schmitt, Christopher J.; Bartish, Timothy M.; Denslow, Nancy D.; Blazer, Vicki; Anderson, Patrick J.; Coyle, James J.; Dethloff, Gail M.; Tillitt, Donald E.

2004-01-01

Common carp (Cyprinus carpio), black basses (Micropterus sp.), and largescale sucker (Catostomus macrocheilus) together accounted for 80% of the fish sampled during the study. Fish were weighed and measured then field-examined for external and internal lesions, and liver, spleen, and gonads were weighed to compute somatic indices. Selected tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Composite samples of whole fish from each station were grouped by species and gender and analyzed for persistent organic and inorganic contaminants and for dioxin-like activity using H4IIE rat hepatoma cell bioassay.

Space motion sickness monitoring experiment - Spacelab 1

NASA Technical Reports Server (NTRS)

Oman, Charles M.; Lichtenberg, Byron K.; Money, Kenneth E.

1990-01-01

A detailed firsthand report on symptoms and signs of space motion sickness and fluid shift observed by four specially trained crewmembers during Shuttle/Spacelab 1, launched on November 28, 1983 is presented. Results show that three crewmen experienced persistent overall discomfort and vomited repeatedly. Symptom pattern was generally similar to that seen in the individuals preflight, except that prodromalnausea was brief or absent in some cases. Symptoms were clearly modulated by head movement, were exacerbated by unfamiliar visual cues, and could be reduced by physical restraint providing contact cues around the body. The results support the view that space sickness is a form of motion sickness.

Spectral-clustering approach to Lagrangian vortex detection.

PubMed

Hadjighasem, Alireza; Karrasch, Daniel; Teramoto, Hiroshi; Haller, George

2016-06-01

One of the ubiquitous features of real-life turbulent flows is the existence and persistence of coherent vortices. Here we show that such coherent vortices can be extracted as clusters of Lagrangian trajectories. We carry out the clustering on a weighted graph, with the weights measuring pairwise distances of fluid trajectories in the extended phase space of positions and time. We then extract coherent vortices from the graph using tools from spectral graph theory. Our method locates all coherent vortices in the flow simultaneously, thereby showing high potential for automated vortex tracking. We illustrate the performance of this technique by identifying coherent Lagrangian vortices in several two- and three-dimensional flows.

[Surgical Repair for Blunt Cardiac Rupture].

PubMed

Yashiki, Noriyoshi; Yachi, Tsuyoshi; Takahashi, Tomohiko

2017-07-01

Blunt cardiac injury is a life-threatening condition. We report 3 successful cases in which we performed surgery for blunt cardiac injury. Three individuals were injured, 2 in traffic accidents and the other being caught between a crane and a steel frame. Echocardiograms and computed tomography scans revealed pooling of bloody pericardial fluid in all 3 patients, who underwent emergency surgery. Two patients needed sutures to control persistent bleeding. Although a heart-lung machine was prepared at the start of surgery in all 3 cases, we did not need to use it for any patient. Thus, prior to performing such surgery, it is necessary to ascertain its need.

Indication of peripheral nerve hyperexcitability in adult-onset subacute sclerosing panencephalitis (SSPE).

PubMed

Schreurs, Annabel; Stålberg, Erik V; Punga, Anna Rostedt

2008-04-01

Subacute sclerosing panencephalitis (SSPE) is a rare chronic, progressive encephalitis that affects primarily children and young adults, caused by a persistent infection of immune-resistant measles virus. Diagnostic hallmarks include widespread cortical dysfunction on EEG, myoclonus, white matter abnormalities on neuroradiological examination and the presence of IgG anti-measles antibodies in the cerebrospinal fluid. We present the first case of SSPE with signs of peripheral nerve hyperexcitability, observed as extra discharges following the compound motor action potential at motor nerve stimulation. In addition we demonstrate the importance of SSPE in the differential diagnosis of adult patients with psychiatric and neurological symptoms.

The influence of pressure on petroleum generation and maturation as suggested by aqueous pyrolysis

USGS Publications Warehouse

Price, L.C.; Wenger, L.M.

1992-01-01

Because fluid pressures are transient in sedimentary basins over geologic time, the effect of increasing fluid pressure on organic-matter metamorphism is difficult to determine, and conflicting opinions exist concerning its influence. Properly-performed aqueous-pyrolysis experiments can closely simulate hydrocarbon generation and maturation in nature, and thus offer an excellent way to study the influence of pressure. Such experiments, carried out on the Retort Phosphatic Shale Member of the Lower Permian Phosphoria Formation (type II-S organic matter) at different constant temperatures, demonstrated that increasing pressure significantly retards all aspects of organic matter metamorphism, including hydrocarbon generation, maturation and thermal destruction. This conclusion results from detailed quantitative and qualitative analyses of all products from hydrocarbon generation, from the C1 to C4 hydrocarbon gases to the asphaltenes, and also from analyses of the reacted rocks. We have documented that our aqueous-pyrolysis experiments closely simulated natural hydrocarbon generation and maturation. Thus the data taken as a function of pressure have relevance to the influence of normal and abnormal fluid pressures as related to: 1) depths and temperatures of mainstage hydrocarbon generation; 2) the thermal destruction of deposits of gas or light oil, or their preservation to unexpectedly high maturation ranks; and 3) the persistence of measurable to moderate concentrations of C15+ hydrocarbons in fine-grained rocks even to ultra-high maturation ranks. ?? 1992.

Steady induction effects in geomagnetism. Part 1A: Steady motional induction of geomagnetic chaos

NASA Technical Reports Server (NTRS)

Voorhies, Coerte V.

1992-01-01

Geomagnetic effects of magnetic induction by hypothetically steady fluid motion and steady magnetic flux diffusion near the top of Earth's core are investigated using electromagnetic theory, simple magnetic earth models, and numerical experiments with geomagnetic field models. The problem of estimating a steady fluid velocity field near the top of Earth's core which induces the secular variation indicated by broad-scale models of the observed geomagnetic field is examined and solved. In Part 1, the steady surficial core flow estimation problem is solved in the context of the source-free mantle/frozen-flux core model. In the first paper (IA), the theory underlying such estimates is reviewed and some consequences of various kinematic and dynamic flow hypotheses are derived. For a frozen-flux core, fluid downwelling is required to change the mean square normal magnetic flux density averaged over the core-mantle boundary. For surficially geostrophic flow, downwelling implies poleward flow. The solution of the forward steady motional induction problem at the surface of a frozen-flux core is derived and found to be a fine, easily visualized example of deterministic chaos. Geomagnetic effects of statistically steady core surface flow may well dominate secular variation over several decades. Indeed, effects of persistent, if not steady, surficially geostrophic core flow are described which may help explain certain features of the present broad-scale geomagnetic field and perhaps paleomagnetic secular variation.

The relationship between baseline pupil size and intelligence.

PubMed

Tsukahara, Jason S; Harrison, Tyler L; Engle, Randall W

2016-12-01

Pupil dilations of the eye are known to correspond to central cognitive processes. However, the relationship between pupil size and individual differences in cognitive ability is not as well studied. A peculiar finding that has cropped up in this research is that those high on cognitive ability have a larger pupil size, even during a passive baseline condition. Yet these findings were incidental and lacked a clear explanation. Therefore, in the present series of studies we systematically investigated whether pupil size during a passive baseline is associated with individual differences in working memory capacity and fluid intelligence. Across three studies we consistently found that baseline pupil size is, in fact, related to cognitive ability. We showed that this relationship could not be explained by differences in mental effort, and that the effect of working memory capacity and fluid intelligence on pupil size persisted even after 23 sessions and taking into account the effect of novelty or familiarity with the environment. We also accounted for potential confounding variables such as; age, ethnicity, and drug substances. Lastly, we found that it is fluid intelligence, more so than working memory capacity, which is related to baseline pupil size. In order to provide an explanation and suggestions for future research, we also consider our findings in the context of the underlying neural mechanisms involved. Copyright © 2016 Elsevier Inc. All rights reserved.

Neuroimaging of Dandy-Walker malformation: new concepts.

PubMed

Correa, Gustavo Gumz; Amaral, Lázaro Faria; Vedolin, Leonardo Modesti

2011-12-01

Dandy-Walker malformation (DWM) is the most common human cerebellar malformation, characterized by hypoplasia of the cerebellar vermis, cystic dilation of the fourth ventricle, and an enlarged posterior fossa with upward displacement of the lateral sinuses, tentorium, and torcular. Although its pathogenesis is not completely understood, there are several genetic loci related to DWM as well as syndromic malformations and congenital infections. Dandy-Walker malformation is associated with other central nervous system abnormalities, including dysgenesis of corpus callosum, ectopic brain tissue, holoprosencephaly, and neural tube defects. Hydrocephalus plays an important role in the development of symptoms and neurological outcome in patients with DWM, and the aim of surgical treatment is usually the control of hydrocephalus and the posterior fossa cyst. Imaging modalities, especially magnetic resonance imaging, are crucial for the diagnosis of DWM and distinguishing this disorder from other cystic posterior fossa lesions. Persistent Blake's cyst is seen as a retrocerebellar fluid collection with cerebrospinal fluid signal intensity and a median line communication with the fourth ventricle, commonly associated with hydrocephalus. Mega cisterna magna presents as an extraaxial fluid collection posteroinferior to an intact cerebellum. Retrocerebellar arachnoid cysts frequently compress the cerebellar hemispheres and the fourth ventricle. Patients with DWM show an enlarged posterior fossa filled with a cystic structure that communicates freely with the fourth ventricle and hypoplastic vermis. Comprehension of hindbrain embryology is of utmost importance for understanding the cerebellar malformations, including DWM, and other related entities.

Development of a New Arterial-Line Filter Design Using Computational Fluid Dynamics Analysis

PubMed Central

Herbst, Daniel P.; Najm, Hani K.

2012-01-01

Abstract: Arterial-line filters used during extracorporeal circulation continue to rely on the physical properties of a wetted micropore and reductions in blood flow velocity to affect air separation from the circulating blood volume. Although problems associated with air embolism during cardiac surgery persist, a number of investigators have concluded that further improvements in filtration are needed to enhance air removal during cardiopulmonary bypass procedures. This article reviews theoretical principles of micropore filter technology and outlines the development of a new arterial-line filter concept using computational fluid dynamics analysis. Manufacturer-supplied data of a micropore screen and experimental results taken from an ex vivo test circuit were used to define the inputs needed for numerical modeling of a new filter design. Flow patterns, pressure distributions, and velocity profiles predicted with computational fluid dynamics softwarewere used to inform decisions on model refinements and how to achieve initial design goals of ≤225 mL prime volume and ≤500 cm2 of screen surface area. Predictions for optimal model geometry included a screen angle of 56° from the horizontal plane with a total surface area of 293.9 cm2 and a priming volume of 192.4 mL. This article describes in brief the developmental process used to advance a new filter design and supports the value of numerical modeling in this undertaking. PMID:23198394

Development of a new arterial-line filter design using computational fluid dynamics analysis.

PubMed

Herbst, Daniel P; Najm, Hani K

2012-09-01

Arterial-line filters used during extracorporeal circulation continue to rely on the physical properties of a wetted micropore and reductions in blood flow velocity to affect air separation from the circulating blood volume. Although problems associated with air embolism during cardiac surgery persist, a number of investigators have concluded that further improvements in filtration are needed to enhance air removal during cardiopulmonary bypass procedures. This article reviews theoretical principles of micropore filter technology and outlines the development of a new arterial-line filter concept using computational fluid dynamics analysis. Manufacturer-supplied data of a micropore screen and experimental results taken from an ex vivo test circuit were used to define the inputs needed for numerical modeling of a new filter design. Flow patterns, pressure distributions, and velocity profiles predicted with computational fluid dynamics software were used to inform decisions on model refinements and how to achieve initial design goals of < or = 225 mL prime volume and < or = 500 cm2 of screen surface area. Predictions for optimal model geometry included a screen angle of 56 degrees from the horizontal plane with a total surface area of 293.9 cm2 and a priming volume of 192.4 mL. This article describes in brief the developmental process used to advance a new filter design and supports the value of numerical modeling in this undertaking.

Biocides in hydraulic fracturing fluids: a critical review of their usage, mobility, degradation, and toxicity.

PubMed

Kahrilas, Genevieve A; Blotevogel, Jens; Stewart, Philip S; Borch, Thomas

2015-01-06

Biocides are critical components of hydraulic fracturing ("fracking") fluids used for unconventional shale gas development. Bacteria may cause bioclogging and inhibit gas extraction, produce toxic hydrogen sulfide, and induce corrosion leading to downhole equipment failure. The use of biocides such as glutaraldehyde and quaternary ammonium compounds has spurred a public concern and debate among regulators regarding the impact of inadvertent releases into the environment on ecosystem and human health. This work provides a critical review of the potential fate and toxicity of biocides used in hydraulic fracturing operations. We identified the following physicochemical and toxicological aspects as well as knowledge gaps that should be considered when selecting biocides: (1) uncharged species will dominate in the aqueous phase and be subject to degradation and transport whereas charged species will sorb to soils and be less bioavailable; (2) many biocides are short-lived or degradable through abiotic and biotic processes, but some may transform into more toxic or persistent compounds; (3) understanding of biocides' fate under downhole conditions (high pressure, temperature, and salt and organic matter concentrations) is limited; (4) several biocidal alternatives exist, but high cost, high energy demands, and/or formation of disinfection byproducts limits their use. This review may serve as a guide for environmental risk assessment and identification of microbial control strategies to help develop a sustainable path for managing hydraulic fracturing fluids.

Environmental Contamination and Persistence of Ebola Virus RNA in an Ebola Treatment Center.

PubMed

Poliquin, Philippe Guillaume; Vogt, Florian; Kasztura, Miriam; Leung, Anders; Deschambault, Yvon; Van den Bergh, Rafael; Dorion, Claire; Maes, Peter; Kamara, Abdul; Kobinger, Gary; Sprecher, Armand; Strong, James E

2016-10-15

 Ebola viruses (EBOVs) are primarily transmitted by contact with infected body fluids. Ebola treatment centers (ETCs) contain areas that are exposed to body fluids through the care of patients suspected or confirmed to have EBOV disease. There are limited data documenting which areas/fomites within ETCs pose a risk for potential transmission. This study conducted environmental surveillance in 2 ETCs in Freetown, Sierra Leone, during the 2014-2016 West African Ebola outbreak.  ETCs were surveyed over a 3-week period. Sites to be swabbed were identified with input from field personnel. Swab samples were collected and tested for the presence of EBOV RNA. Ebola-positive body fluid-impregnated cotton pads were serially sampled.  General areas of both ETCs were negative for EBOV RNA. The immediate vicinity of patients was the area most likely to be positive for EBOV RNA. Personal protective equipment became positive during patient care, but chlorine solution washes rendered them negative.  Personal protective equipment and patient environs do become positive for EBOV RNA, but careful attention to decontamination seems to remove it. EBOV RNA was not detected in general ward spaces. Careful attention to decontamination protocols seems to be important in minimizing the presence of EBOV RNA within ETC wards. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Model of ciliary clearance and the role of mucus rheology

NASA Astrophysics Data System (ADS)

Norton, Michael M.; Robinson, Risa J.; Weinstein, Steven J.

2011-01-01

It has been observed that the transportability of mucus by cilial mats is dependent on the rheological properties of the mucus. Mucus is a non-Newtonian fluid that exhibits a plethora of phenomena such as stress relaxation, tensile stresses, shear thinning, and yielding behavior. These observations motivate the analysis in this paper that considers the first two attributes in order to construct a transport model. The model developed here assumes that the mucus is transported as a rigid body, the metachronal wave exhibits symplectic behavior, that the mucus is thin compared to the metachronal wavelength, and that the effects of individual cilia can be lumped together to impart an average strain to the mucus during contact. This strain invokes a stress in the mucus, whose non-Newtonian rheology creates tensile forces that persist into unsheared regions and allow the unsupported mucus to move as a rigid body whereas a Newtonian fluid would retrograde. This work focuses primarily on the Doi-Edwards model but results are generalized to the Jeffrey's fluid as well. The model predicts that there exists an optimal mucus rheology that maximizes the shear stress imparted to the mucus by the cilia for a given cilia motion. We propose that this is the rheology that the body strives for in order to minimize energy consumption. Predicted optimal rheologies are consistent with results from previous experimental studies when reasonable model parameters are chosen.

Acute effects of polychlorinated biphenyl-containing and -free transformer fluids on rat testicular steroidogenesis.

PubMed Central

Andric, S A; Kostic, T S; Dragisic, S M; Andric, N L; Stojilkovic, S S; Kovacevic, R Z

2000-01-01

Polychlorinated biphenyl (PCB)-based transformer fluids belong to a class of environmentally persistent mixtures with known toxic effects. Here, we studied the acute effects of Askarel (which contains Aroclor 1260) and two substitute transformer fluids (the silicone oil-based DC561 and the mineral oil-based ENOL C) on rat testicular steroidogenesis. Single intraperitoneal (ip; 10 mg/kg body weight) or bilateral intratesticular (itt; 25 microg/testis) injections of Askarel markedly decreased serum androgen levels 24 hr after administration. In acute testicular cultures from these animals, chorionic gonadotropin-stimulated progesterone and androgen productions were severely attenuated. When itt was injected or added in vitro, Askarel inhibited 3ss-hydroxysteroid dehydrogenase (3ssHSD), stimulated 17[alpha]-hydroxylase/lyase (P450c17), and did not affect 17ss-hydroxysteroid dehydrogenase in testicular postmitochondrial fractions. The ip-injected Askarel did not affect 3ssHSD, but inhibited P450c17, suggesting that a more intensive metabolism of peripherally injected Askarel reduces the circulating levels of active ingredients below the threshold needed for inhibition of 3ssHSD and generates a derivative that inhibits P450c17. In contrast to Askarel, itt-injection (25 microg/testis) of DC561 and ENOL C did not affect in vivo and in vitro steroidogenesis. These findings show the acute effects of Askarel, but not silicone and mineral oils, on testicular steroidogenesis. PMID:11049815

Microstructural evolution of a model, shear-banding micellar solution during shear startup and cessation.

PubMed

López-Barrón, Carlos R; Gurnon, A Kate; Eberle, Aaron P R; Porcar, Lionel; Wagner, Norman J

2014-04-01

We present direct measurements of the evolution of the segmental-level microstructure of a stable shear-banding polymerlike micelle solution during flow startup and cessation in the plane of flow. These measurements provide a definitive, quantitative microstructural understanding of the stages observed during flow startup: an initial elastic response with limited alignment that yields with a large stress overshoot to a homogeneous flow with associated micellar alignment that persists for approximately three relaxation times. This transient is followed by a shear (kink) band formation with a flow-aligned low-viscosity band that exhibits shear-induced concentration fluctuations and coexists with a nearly isotropic band of homogenous, highly viscoelastic micellar solution. Stable, steady banding flow is achieved only after approximately two reptation times. Flow cessation from this shear-banded state is also found to be nontrivial, exhibiting an initial fast relaxation with only minor structural relaxation, followed by a slower relaxation of the aligned micellar fluid with the equilibrium fluid's characteristic relaxation time. These measurements resolve a controversy in the literature surrounding the mechanism of shear banding in entangled wormlike micelles and, by means of comparison to existing literature, provide further insights into the mechanisms driving shear-banding instabilities in related systems. The methods and instrumentation described should find broad use in exploring complex fluid rheology and testing microstructure-based constitutive equations.

Aflibercept treatment for neovascular AMD beyond the first year: consensus recommendations by a UK expert roundtable panel, 2017 update

PubMed Central

Patel, Praveen J; Devonport, Helen; Sivaprasad, Sobha; Ross, Adam H; Walters, Gavin; Gale, Richard P; Lotery, Andrew J; Mahmood, Sajjad; Talks, James S; Napier, Jackie

2017-01-01

National recommendations on continued administration of aflibercept solution for injection after the first year of treatment for neovascular age-related macular degeneration (nAMD) have been developed by an expert panel of UK retina specialists, based on clinician experience and treatment outcomes seen in year 2. The 2017 update reiterates that the treatment goal is to maintain or improve the macular structural and functional gains achieved in year 1 while attempting to reduce or minimize the treatment burden, recognizing the need for ongoing treatment. At the end of year 1 (ie, the decision visit at month 11), two treatment options should be considered: do not extend the treatment interval and maintain fixed 8-weekly dosing, or extend the treatment interval using a treat-and-extend regimen up to a maximum 12 weeks. Criteria for considering not extending the treatment interval are persistent macular fluid with stable vision, recurrent fluid, decrease in vision in the presence of fluid, macular hemorrhage, new choroidal neovascularization or any other sign(s) of exudative disease activity considered vision threatening in the opinion of the treating clinician. Treatment extension is recommended for eyes with a dry macula (ie, without macular fluid) and stable vision. Under both options, the treatment interval may be shortened if visual and/or anatomic outcomes deteriorate. Monitoring without treatment may be considered for eyes with a fluid-free macula for a minimum duration of 48 weeks. A patient completing one full year of monitoring without requiring injections may be considered for discharge from clinic. The treatment algorithm incorporates return to fixed 8-weekly dosing for disease reactivation during treatment extension and reinstatement of treatment for disease recurrence following discontinuation or discharge. For bilateral nAMD, either the eye requiring the more intensive treatment or the eye with the better vision, guided by local clinical practice, should determine the retreatment schedule overall. PMID:29184385

Aflibercept treatment for neovascular AMD beyond the first year: consensus recommendations by a UK expert roundtable panel, 2017 update.

PubMed

Patel, Praveen J; Devonport, Helen; Sivaprasad, Sobha; Ross, Adam H; Walters, Gavin; Gale, Richard P; Lotery, Andrew J; Mahmood, Sajjad; Talks, James S; Napier, Jackie

2017-01-01

National recommendations on continued administration of aflibercept solution for injection after the first year of treatment for neovascular age-related macular degeneration (nAMD) have been developed by an expert panel of UK retina specialists, based on clinician experience and treatment outcomes seen in year 2. The 2017 update reiterates that the treatment goal is to maintain or improve the macular structural and functional gains achieved in year 1 while attempting to reduce or minimize the treatment burden, recognizing the need for ongoing treatment. At the end of year 1 (ie, the decision visit at month 11), two treatment options should be considered: do not extend the treatment interval and maintain fixed 8-weekly dosing, or extend the treatment interval using a treat-and-extend regimen up to a maximum 12 weeks. Criteria for considering not extending the treatment interval are persistent macular fluid with stable vision, recurrent fluid, decrease in vision in the presence of fluid, macular hemorrhage, new choroidal neovascularization or any other sign(s) of exudative disease activity considered vision threatening in the opinion of the treating clinician. Treatment extension is recommended for eyes with a dry macula (ie, without macular fluid) and stable vision. Under both options, the treatment interval may be shortened if visual and/or anatomic outcomes deteriorate. Monitoring without treatment may be considered for eyes with a fluid-free macula for a minimum duration of 48 weeks. A patient completing one full year of monitoring without requiring injections may be considered for discharge from clinic. The treatment algorithm incorporates return to fixed 8-weekly dosing for disease reactivation during treatment extension and reinstatement of treatment for disease recurrence following discontinuation or discharge. For bilateral nAMD, either the eye requiring the more intensive treatment or the eye with the better vision, guided by local clinical practice, should determine the retreatment schedule overall.

Metamorphosed Plio-Pleistocene evaporites and the origins of hypersaline brines in the Salton Sea geothermal system, California: Fluid inclusion evidence

NASA Astrophysics Data System (ADS)

McKibben, Michael A.; Williams, Alan E.; Okubo, Susumu

1988-05-01

The Salton Sea geothermal system (SSGS) occurs in Plio-Pleistocene deltaic-lacustrine-evaporite sediments deposited in the Salton Trough, an active continental rift zone. Temperatures up to 365°C and hypersaline brines with up to 26 wt.% TDS are encountered at 1-3 km depth in the sediments, which are undergoing active greenschist facies hydrothermal metamorphism. Previous models for the origins of the Na-Ca-K-Cl brines have assumed that the high salinities were derived mainly from the downward percolation of cold, dense brines formed by low-temperature dissolution of shallow non-marine evaporites. New drillcores from the central part of the geothermal field contain metamorphosed, bedded evaporites at 1 km depth consisting largely of hornfelsic anhydrite interbedded with anhydrite-cemented solution-collapse shale breccias. Fluid inclusions trapped within the bedded and breccia-cementing anhydrite homogenize at 300°C (identical to the measured downhole temperature) and contain saline Na-Ca-K-Cl brines. Some of the inclusions contain up to 50 vol.% halite, sylvite and carbonate crystals at room temperature, and some halite crystals persist to above 300°C upon laboratory heating. The data are consistent with the trapping of halite-saturated Na-Ca-K-Cl fluids during hydrothermal metamorphism of the evaporites and accompanying solution collapse of interbedded shales. We conclude that many of the salt crystals in inclusions are the residuum of bedded evaporitic salt that was dissolved during metamorphism by heated connate fluids. Therefore, the high salinities of the Salton Sea geothermal brines are derived in part from the in situ hydrothermal metamorphism and dissolution of halides and CaSO 4 from relatively deeply-buried lacustrine evaporites. This fact places important constraints on modeling fluid-flow in the SSGS, as brines need not have migrated over great distances. The brines have been further modified to their present complex Na-Ca-K-Fe-Mn-Cl compositions by on-going sediment metamorphism and water-rock interaction.

Fluid‐driven seismicity response of the Rinconada fault near Paso Robles, California, to the 2003 M 6.5 San Simeon earthquake

USGS Publications Warehouse

Hardebeck, Jeanne L.

2012-01-01

The 2003 M 6.5 San Simeon, California, earthquake caused significant damage in the city of Paso Robles and a persistent cluster of aftershocks close to Paso Robles near the Rinconada fault. Given the importance of secondary aftershock triggering in sequences of large events, a concern is whether this cluster of events could trigger another damaging earthquake near Paso Robles. An epidemic‐type aftershock sequence (ETAS) model is fit to the Rinconada seismicity, and multiple realizations indicate a 0.36% probability of at least one M≥6.0 earthquake during the next 30 years. However, this probability estimate is only as good as the projection into the future of the ETAS model. There is evidence that the seismicity may be influenced by fluid pressure changes, which cannot be forecasted using ETAS. The strongest evidence for fluids is the delay between the San Simeon mainshock and a high rate of seismicity in mid to late 2004. This delay can be explained as having been caused by a pore pressure decrease due to an undrained response to the coseismic dilatation, followed by increased pore pressure during the return to equilibrium. Seismicity migration along the fault also suggests fluid involvement, although the migration is too slow to be consistent with pore pressure diffusion. All other evidence, including focal mechanisms and b‐value, is consistent with tectonic earthquakes. This suggests a model where the role of fluid pressure changes is limited to the first seven months, while the fluid pressure equilibrates. The ETAS modeling adequately fits the events after July 2004 when the pore pressure stabilizes. The ETAS models imply that while the probability of a damaging earthquake on the Rinconada fault has approximately doubled due to the San Simeon earthquake, the absolute probability remains low.

Scales of equilibrium and disequilibrium during cleavage formation in chlorite and biotite-grade phyllites, SE Vermont

USGS Publications Warehouse

McWilliams, C.K.; Wintsch, R.P.; Kunk, Michael J.

2007-01-01

Detailed electron microprobe analyses of phyllosilicates in crenulated phyllites from south-eastern Vermont show that grain-scale zoning is common, and sympathetic zoning in adjacent minerals is nearly universal. We interpret this to reflect a pressure-solution mechanism for cleavage development, where precipitation from a very small fluid reservoir fractionated that fluid. Multiple analyses along single muscovite, biotite and chlorite grains (30–200 μm in length) show zoning patterns indicating Tschermakitic substitutions in muscovite and both Tschermakitic and di/trioctahedral substitutions in biotite and chlorite. Using cross-cutting relationships and mineral chemistry it is shown that these patterns persist in cleavages produced at metamorphic conditions of chlorite-grade, chlorite-grade overprinted by biotite-grade and biotite-grade. Zoning patterns are comparable in all three settings, requiring a similar cleavage-forming mechanism independent of metamorphic grade. Moreover, the use of 40Ar/39Ar geochronology demonstrates this is true regardless of age. Furthermore, samples with chlorite-grade cleavages overprinted by biotite porphyroblasts suggest the closure temperatures for the diffusion of Al, Si, Mg and Fe ions are greater than the temperature of the biotite isograd (>∼400 °C). Parallel and smoothly fanning tie lines produced by coexisting muscovite–chlorite, and muscovite–biotite pairs on compositional diagrams demonstrate effectively instantaneous chemical equilibrium and probably indicate simultaneous crystallization.These results do not support theories suggesting cleavages form in fluid-dominated systems. If crenulation cleavages formed in systems in which the chemical potentials of all major components are fixed by an external reservoir, then the compositions of individual grains defining these cleavages would be uniform. On the contrary, the fine-scale chemical zoning observed probably reflects a grain-scale process consistent with a pressure-solution mechanism in which the aqueous activities of major components are defined by local dissolution and precipitation. Thus the role of fluids was probably limited to one of catalysing pressure-solution and fluids apparently did not drive cleavage development.

Non-intrusive telemetry applications in the oilsands: from visible light and x-ray video to acoustic imaging and spectroscopy

NASA Astrophysics Data System (ADS)

Shaw, John M.

2013-06-01

While the production, transport and refining of oils from the oilsands of Alberta, and comparable resources elsewhere is performed at industrial scales, numerous technical and technological challenges and opportunities persist due to the ill defined nature of the resource. For example, bitumen and heavy oil comprise multiple bulk phases, self-organizing constituents at the microscale (liquid crystals) and the nano scale. There are no quantitative measures available at the molecular level. Non-intrusive telemetry is providing promising paths toward solutions, be they enabling technologies targeting process design, development or optimization, or more prosaic process control or process monitoring applications. Operation examples include automated large object and poor quality ore during mining, and monitoring the thickness and location of oil water interfacial zones within separation vessels. These applications involve real-time video image processing. X-ray transmission video imaging is used to enumerate organic phases present within a vessel, and to detect individual phase volumes, densities and elemental compositions. This is an enabling technology that provides phase equilibrium and phase composition data for production and refining process development, and fluid property myth debunking. A high-resolution two-dimensional acoustic mapping technique now at the proof of concept stage is expected to provide simultaneous fluid flow and fluid composition data within porous inorganic media. Again this is an enabling technology targeting visualization of diverse oil production process fundamentals at the pore scale. Far infrared spectroscopy coupled with detailed quantum mechanical calculations, may provide characteristic molecular motifs and intermolecular association data required for fluid characterization and process modeling. X-ray scattering (SAXS/WAXS/USAXS) provides characteristic supramolecular structure information that impacts fluid rheology and process fouling. The intent of this contribution is to present some of the challenges and to provide an introduction grounded in current work on non-intrusive telemetry applications - from a mine or reservoir to a refinery!

Fluctuations of wormlike micelle fluids in capillary flow

NASA Astrophysics Data System (ADS)

Salipante, Paul; Meek, Stephen; Hudson, Steven; Polymers; Complex Fluids Group Team

2017-11-01

We investigate the effect of entrance geometry on the flow stability of wormlike micelles solutions in capillary flow. These solutions exhibit strong shear thinning behavior resulting from micelle breakage and have been observed to undergo large flow rate fluctuations. We investigate these fluctuations using simultaneous measurements of flow rate and pressure drop across a capillary, and we adjust entrance geometry. With a tapered constriction, we observe large persistent fluctuations above a critical flow rate, characterized by rapid decreases in the pressure drop with corresponding increase in flow rate followed by a period of recovery where pressure increases and flow rate decreases. Flow field observations in the tapered entrance show large flow circulations. An abrupt contraction produces smaller transient fluidized jets forming upstream of the constriction and the magnitude of the fluctuations are significantly diminished. The effect of fluid properties is studied by comparing the magnitude and timescales of the fluctuations for surfactant systems with different relaxation times. The onset of fluctuations is compared to a criterion for the onset of elastic instabilities and the magnitude is compared to estimates for changes in channel resistance. NIST on a Chip.

Indeterminism in Classical Dynamics of Particle Motion

NASA Astrophysics Data System (ADS)

Eyink, Gregory; Vishniac, Ethan; Lalescu, Cristian; Aluie, Hussein; Kanov, Kalin; Burns, Randal; Meneveau, Charles; Szalay, Alex

2013-03-01

We show that ``God plays dice'' not only in quantum mechanics but also in the classical dynamics of particles advected by turbulent fluids. With a fixed deterministic flow velocity and an exactly known initial position, the particle motion is nevertheless completely unpredictable! In analogy with spontaneous magnetization in ferromagnets which persists as external field is taken to zero, the particle trajectories in turbulent flow remain random as external noise vanishes. The necessary ingredient is a rough advecting field with a power-law energy spectrum extending to smaller scales as noise is taken to zero. The physical mechanism of ``spontaneous stochasticity'' is the explosive dispersion of particle pairs proposed by L. F. Richardson in 1926, so the phenomenon should be observable in laboratory and natural turbulent flows. We present here the first empirical corroboration of these effects in high Reynolds-number numerical simulations of hydrodynamic and magnetohydrodynamic fluid turbulence. Since power-law spectra are seen in many other systems in condensed matter, geophysics and astrophysics, the phenomenon should occur rather widely. Fast reconnection in solar flares and other astrophysical systems can be explained by spontaneous stochasticity of magnetic field-line motion

Rapid simulated gastric fluid digestion of in-seed/grain proteins expressed in genetically engineered crops.

PubMed

Schafer, Barry W; Embrey, Shawna K; Herman, Rod A

2016-11-01

The speed of simulated gastric digestion of proteins expressed in genetically engineered (GE) crops is commonly used to inform the allergenicity risk assessment. However, persistence of purified proteins in simulated gastric fluid (SGF) is poorly correlated with the allergenic status of proteins. It has been proposed that the plant or food matrix may affect the digestion of proteins and should be considered in interpreting digestion results. Here the SGF digestion of several GE proteins both as purified preparations and in soybean, corn, and cotton seed/grain extracts (in-matrix) are compared. Cry1F, Cry1Ac, phosphinothricin acetyltransferase (PAT), aryloxyalkanoate dioxygenase-1 (AAD-1), aryloxyalkanoate dioxygenase-12 (AAD-12), and double mutant 5-enol pyruvylshikimate-3-phosphate synthase (2mEPSPS) were all found to rapidly digest both as purified protein preparations and in seed/grain extracts from GE crops expressing these proteins. Based on these results, purified protein from microbial sources is a suitable surrogate for proteins in-matrix when conducting SGF digestion studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Reconstruction of large cranial defect with alloplastic material (bone cement-cold cure polymethyl-methacrylate resin).

PubMed

Hallur, Neelakamal; Goudar, Gayatri; Sikkerimath, Basavaraj; Gudi, Santosh S; Patil, Ravi S

2010-06-01

A 40-years-old male patient reported to our department with a chief complaint of persistent palatal fluid discharge and large depressed forehead defect. He gave a history of trauma 20 months back due to head on collision to electric pole and underwent surgery twice for open reduction and fixation of facial skeletal fractures. After 9 months of surgery again a third surgery was performed for the removal of frontal bone due to infection and osteomyelitis at the same site. Extra-oral examination revealed a large fronto-cranial defect extending from superior border of frontal bone to supra-orbital margins bilaterally in length, and from frontal right lateral to frontal left lateral side in width, measuring 8.0 cm in length, 10.5 cm in width and 1.5 to 2.0 cm in depth. Intra-oral sinus fluid discharge was from left posterior palatal region. Preoperative CT was taken and reconstruction of fronto-cranial defect was successfully performed with bone cement. Alloplastic implant reconstruction achieved an excellent esthetic result without any complications.

Coral resistance to ocean acidification linked to increased calcium at the site of calcification.

PubMed

DeCarlo, T M; Comeau, S; Cornwall, C E; McCulloch, M T

2018-05-16

Ocean acidification threatens the persistence of biogenic calcium carbonate (CaCO 3 ) production on coral reefs. However, some coral genera show resistance to declines in seawater pH, potentially achieved by modulating the chemistry of the fluid where calcification occurs. We use two novel geochemical techniques based on boron systematics and Raman spectroscopy, which together provide the first constraints on the sensitivity of coral calcifying fluid calcium concentrations ([Formula: see text]) to changing seawater pH. In response to simulated end-of-century pH conditions, Pocillopora damicornis increased [Formula: see text] to as much as 25% above that of seawater and maintained constant calcification rates. Conversely, Acropora youngei displayed less control over [Formula: see text], and its calcification rates strongly declined at lower seawater pH. Although the role of [Formula: see text] in driving calcification has often been neglected, increasing [Formula: see text] may be a key mechanism enabling more resistant corals to cope with ocean acidification and continue to build CaCO 3 skeletons in a high-CO 2 world. © 2018 The Author(s).

Skull Base Cerebrospinal Fluid Leakage Control with a Fibrin-Based Composite Tissue Adhesive

PubMed Central

Rock, Jack P.; Sierra, David H.; Castro-Moure, Frederico; Jiang, Feng

1996-01-01

Cerebrospinal fluid (CSF) leaks can be responsible for significant patient morbidity and mortality. While the majority of leaks induced after head trauma will seal without intervention, spontaneous or surgically-induced leaks often require operative repair. Many modifications on standard surgical technique are available for repair of CSF fistulae, but none assures adequate closure. We have studied the efficacy of a novel fibrin-based composite tissue adhesive (CTA) for closure of experimentally-induced CSF leaks in rats. Fistulae were created in two groups of animals. Two weeks after creation of the leaks, the animals were sacrificed and analyzed for persistence of leak. A 58% leakage rate was noted in the control group (n = 12), and no leaks were noted in the experimental group closed after application of CTA to the surgical defect followed by skin closure (n = 11). Comparing the control group to the experimental group, results were statistically significant (p = 0.015). These data suggest that CTA may be effective as an adjunct for the closure of CSF fistulae. ImagesFigure 2Figure 3 PMID:17170969

A diagnostic predicament: activated sarcoidosis or pulmonary histoplasmosis. A case report.

PubMed

Lingscheid, Tilman; von Heinz, Marie; Klages, Birgit; Rickerts, Volker; Tintelnot, Kathrin; Gerhold, Manuela; Oestmann, Jörg-Wilhelm; Becker, Markus; Temmesfeld-Wollbrück, Bettina; Suttorp, Norbert; Hübner, Ralf-Harto

2017-05-01

We report a case of a 41-year-old man presenting with persisting fevers over 2 weeks. The patient had spent 4 weeks in Central America. He was in control of a stable stage II sarcoidosis. Laboratory and various microbiological tests as well as chest radiography led to no diagnosis. Activated sarcoidosis was hypothesized as the most likely diagnosis. However, we considered an infectious process as a differential diagnosis, in detail, the travel history imposed histoplasmosis. Chest-CT documented localized interstitial consolidations. Bronchoscopy with bronchoalveolar lavage (BAL) and biopsy was performed. Results of BAL fluid, biopsy, distinct sarcoidosis serum markers and a borderline positive histoplasmosis-serology yielded in a diagnostic dilemma as no distinct diagnosis was drawable. After the patient was already started on a prednisolone trial, the final diagnosis - pulmonary histoplasmosis - could be achieved via positive culture and PCR out of the BAL fluid. This case shows the difficult differentiation between an acute exacerbation of a chronic pulmonary disease and a concomitant infection, which was especially aggravated in this case as the histoplasmosis masqueraded an acute picture of sarcoidosis. © 2015 John Wiley & Sons Ltd.

Variation in bed level shear stress on surfaces sheltered by nonerodible roughness elements

NASA Astrophysics Data System (ADS)

Sutton, Stephen L. F.; McKenna-Neuman, Cheryl

2008-09-01

Direct bed level observations of surface shear stress, pressure gradient variability, turbulence intensity, and fluid flow patterns were carried out in the vicinity of cylindrical roughness elements mounted in a boundary layer wind tunnel. Paired corkscrew vortices shed from each of the elements result in elevated shear stress and increased potential for the initiation of particle transport within the far wake. While the size and shape of these trailing vortices change with the element spacing, they persist even for large roughness densities. Wake interference coincides with the impingement of the upwind horseshoe vortices upon one another at a point when their diameter approaches half the distance between the roughness elements. While the erosive capability of the horseshoe vortex has been suggested for a variety of settings, the present study shows that the fluid stress immediately beneath this coherent structure is actually small in comparison to that caused by compression of the incident flow as it is deflected around the element and attached vortex. Observations such as these are required for further refinement of models of stress partitioning on rough surfaces.

Structure, thermodynamics, and solubility in tetromino fluids.

PubMed

Barnes, Brian C; Siderius, Daniel W; Gelb, Lev D

2009-06-16

To better understand the self-assembly of small molecules and nanoparticles adsorbed at interfaces, we have performed extensive Monte Carlo simulations of a simple lattice model based on the seven hard "tetrominoes", connected shapes that occupy four lattice sites. The equations of state of the pure fluids and all of the binary mixtures are determined over a wide range of density, and a large selection of multicomponent mixtures are also studied at selected conditions. Calculations are performed in the grand canonical ensemble and are analogous to real systems in which molecules or nanoparticles reversibly adsorb to a surface or interface from a bulk reservoir. The model studied is athermal; objects in these simulations avoid overlap but otherwise do not interact. As a result, all of the behavior observed is entropically driven. The one-component fluids all exhibit marked self-ordering tendencies at higher densities, with quite complex structures formed in some cases. Significant clustering of objects with the same rotational state (orientation) is also observed in some of the pure fluids. In all of the binary mixtures, the two species are fully miscible at large scales, but exhibit strong species-specific clustering (segregation) at small scales. This behavior persists in multicomponent mixtures; even in seven-component mixtures of all the shapes there is significant association between objects of the same shape. To better understand these phenomena, we calculate the second virial coefficients of the tetrominoes and related quantities, extract thermodynamic volume of mixing data from the simulations of binary mixtures, and determine Henry's law solubilities for each shape in a variety of solvents. The overall picture obtained is one in which complementarity of both the shapes of individual objects and the characteristic structures of different fluids are important in determining the overall behavior of a fluid of a given composition, with sometimes counterintuitive results. Finally, we note that no sharp phase transitions are observed but that this appears to be due to the small size of the objects considered. It is likely that complex phase behavior may be found in systems of larger polyominoes.

The seismogenic Gole Larghe Fault Zone (Italian Southern Alps): quantitative 3D characterization of the fault/fracture network, mapping of evidences of fluid-rock interaction, and modelling of the hydraulic structure through the seismic cycle

NASA Astrophysics Data System (ADS)

Bistacchi, A.; Mittempergher, S.; Di Toro, G.; Smith, S. A. F.; Garofalo, P. S.

2016-12-01

The Gole Larghe Fault Zone (GLFZ) was exhumed from 8 km depth, where it was characterized by seismic activity (pseudotachylytes) and hydrous fluid flow (alteration halos and precipitation of hydrothermal minerals in veins and cataclasites). Thanks to glacier-polished outcrops exposing the 400 m-thick fault zone over a continuous area > 1.5 km2, the fault zone architecture has been quantitatively described with an unprecedented detail, providing a rich dataset to generate 3D Discrete Fracture Network (DFN) models and simulate the fault zone hydraulic properties. The fault and fracture network has been characterized combining > 2 km of scanlines and semi-automatic mapping of faults and fractures on several photogrammetric 3D Digital Outcrop Models (3D DOMs). This allowed obtaining robust probability density functions for parameters of fault and fracture sets: orientation, fracture intensity and density, spacing, persistency, length, thickness/aperture, termination. The spatial distribution of fractures (random, clustered, anticlustered…) has been characterized with geostatistics. Evidences of fluid/rock interaction (alteration halos, hydrothermal veins, etc.) have been mapped on the same outcrops, revealing sectors of the fault zone strongly impacted, vs. completely unaffected, by fluid/rock interaction, separated by convolute infiltration fronts. Field and microstructural evidence revealed that higher permeability was obtained in the syn- to early post-seismic period, when fractures were (re)opened by off-fault deformation. We have developed a parametric hydraulic model of the GLFZ and calibrated it, varying the fraction of faults/fractures that were open in the post-seismic, with the goal of obtaining realistic fluid flow and permeability values, and a flow pattern consistent with the observed alteration/mineralization pattern. The fraction of open fractures is very close to the percolation threshold of the DFN, and the permeability tensor is strongly anisotropic, resulting in a marked channelling of fluid flow in the inner part of the fault zone. Amongst possible seismological applications of our study, we will discuss the possibility to evaluate the coseismic fracture intensity due to off-fault damage, a fundamental mechanical parameter in the energy balance of earthquakes.

Expression of immune response genes in the stifle joint of dogs with oligoarthritis and degenerative cranial cruciate ligament rupture.

PubMed

Muir, P; Schaefer, S L; Manley, P A; Svaren, J P; Oldenhoff, W E; Hao, Z

2007-10-15

Dysregulation of immune responses within joints plays an important role in development of inflammatory arthritis. We determined expression of a panel of immune response and matrix turnover genes in synovial fluid collected from a group of dogs with stifle oligoarthritis and associated degenerative cranial cruciate ligament (CCL) rupture (n=27). We also studied synovial fluid gene expression in dogs affected with other forms of degenerative arthritis (n=9) and in the stifle joint of healthy dogs with intact CCL (n=14). After collection, synovial cells were pelleted and RNA was isolated. Relative expression of cathepsin K, cathepsin S, tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-9 (MMP-9), invariant chain (li), toll-like receptor-2 (TLR-2), and TLR-9 was determined using real-time quantitative RT-PCR. Data were normalized to peripheral blood mononuclear cells (PBMC) as an internal control. Relative expression of cathepsin K, MMP-9, TRAP, and li was increased in the stifle synovial fluid of dogs with oligoarthritis, when compared with the stifles of healthy dogs (P<0.05). In contrast, relative expression of all of the genes-of-interest in synovial fluid from joints affected with other forms of arthritis was not significantly different from the stifles of healthy dogs. TRAP expression was also significantly increased in the stifle joints of dogs with oligoarthritis, when compared to joint expression of TRAP in dogs with other forms of degenerative arthritis (P<0.05). In the dogs with stifle oligoarthritis, expression of both matrix turnover and immune response genes was increased in stifle synovial fluid, when compared with the internal PBMC control, whereas in healthy dogs and dogs with other forms of arthritis, only expression of matrix turnover genes was increased in synovial fluid, when compared with the internal PBMC control (P<0.05). Taken together, these findings suggest that antigen-specific immune responses within the stifle joint may be involved in the pathogenesis of persistent synovitis and associated joint degradation in dogs with oligoarthritis and degenerative CCL rupture.

Profiling of Candida albicans Gene Expression During Intra-abdominal Candidiasis Identifies Biologic Processes Involved in Pathogenesis

PubMed Central

Cheng, Shaoji; Clancy, Cornelius J.; Xu, Wenjie; Schneider, Frank; Hao, Binghua; Mitchell, Aaron P.; Nguyen, M. Hong

2013-01-01

Background. The pathogenesis of intra-abdominal candidiasis is poorly understood. Methods. Mice were intraperitoneally infected with Candida albicans (1 × 106 colony-forming units) and sterile stool. nanoString assays were used to quantitate messenger RNA for 145 C. albicans genes within the peritoneal cavity at 48 hours. Results. Within 6 hours after infection, mice developed peritonitis, characterized by high yeast burdens, neutrophil influx, and a pH of 7.9 within peritoneal fluid. Organ invasion by hyphae and early abscess formation were evident 6 and 24 hours after infection, respectively; abscesses resolved by day 14. nanoString assays revealed adhesion and responses to alkaline pH, osmolarity, and stress as biologic processes activated in the peritoneal cavity. Disruption of the highly-expressed gene RIM101, which encodes an alkaline-regulated transcription factor, did not impact cellular morphology but reduced both C. albicans burden during early peritonitis and C. albicans persistence within abscesses. RIM101 influenced expression of 49 genes during intra-abdominal candidiasis, including previously unidentified Rim101 targets. Overexpression of the RIM101-dependent gene SAP5, which encodes a secreted protease, restored the ability of a rim101 mutant to persist within abscesses. Conclusions. A mouse model of intra-abdominal candidiasis is valuable for studying pathogenesis and C. albicans gene expression. RIM101 contributes to persistence within intra-abdominal abscesses, at least in part through activation of SAP5. PMID:24006479

Results of repeated transsphenoidal surgery in Cushing's disease. Long-term follow-up.

PubMed

Valderrábano, Pablo; Aller, Javier; García-Valdecasas, Leopoldo; García-Uría, José; Martín, Laura; Palacios, Nuria; Estrada, Javier

2014-04-01

Transsphenoidal surgery (TSS) is the treatment of choice for Cushing's disease (CD). However, the best treatment option when hypercortisolism persists or recurs remains unknown. The aim of this study was to analyze the short and long-term outcome of repeat TSS in this situation and to search for response predictors. Data from 26 patients with persistent (n=11) or recurrent (n=15) hypercortisolism who underwent repeat surgery by a single neurosurgeon between 1982 and 2009 were retrospectively analyzed. Remission was defined as normalization of urinary free cortisol (UFC) levels, and recurrence as presence of elevated UFC levels after having achieved remission. The following potential outcome predictors were analyzed: adrenal status (persistence or recurrence) after initial TSS, tumor identification in imaging tests, degree of hypercortisolism before repeat TSS, same/different surgeon in both TSS, and time to repeat surgery. Immediate postoperative remission was achieved in 12 patients (46.2%). Five of the 10 patients with available follow-up data relapsed after surgery (median time to recurrence, 13 months). New hormone deficiencies were seen in seven patients (37%), and two patients had cerebrospinal fluid leakage. No other major complications occurred. None of the preoperative factors analyzed was predictive of surgical outcome. When compared to initial surgery, repeat TSS for CD is associated to a lower remission rate and a higher risk of recurrence and complications. Further studies are needed to define outcome predictors. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

Congenital heart disease affects cerebral size but not brain growth.

PubMed

Ortinau, Cynthia; Inder, Terrie; Lambeth, Jennifer; Wallendorf, Michael; Finucane, Kirsten; Beca, John

2012-10-01

Infants with congenital heart disease (CHD) have delayed brain maturation and alterations in brain volume. Brain metrics is a simple measurement technique that can be used to evaluate brain growth. This study used brain metrics to test the hypothesis that alterations in brain size persist at 3 months of age and that infants with CHD have slower rates of brain growth than control infants. Fifty-seven infants with CHD underwent serial brain magnetic resonance imaging (MRI). To evaluate brain growth across the first 3 months of life, brain metrics were undertaken using 19 tissue and fluid spaces shown on MRIs performed before surgery and again at 3 months of age. Before surgery, infants with CHD have smaller frontal, parietal, cerebellar, and brain stem measures (p < 0.001). At 3 months of age, alterations persisted in all measures except the cerebellum. There was no difference between control and CHD infants in brain growth. However, the cerebellum trended toward greater growth in infants with CHD. Somatic growth was the primary factor that related to brain growth. Presence of focal white matter lesions before and after surgery did not relate to alterations in brain size or growth. Although infants with CHD have persistent alterations in brain size at 3 months of age, rates of brain growth are similar to that of healthy term infants. Somatic growth was the primary predictor of brain growth, emphasizing the importance of optimal weight gain in this population.

High-throughput sequencing of TCR repertoires in multiple sclerosis reveals intrathecal enrichment of EBV-reactive CD8+ T cells.

PubMed

Lossius, Andreas; Johansen, Jorunn N; Vartdal, Frode; Robins, Harlan; Jūratė Šaltytė, Benth; Holmøy, Trygve; Olweus, Johanna

2014-11-01

Epstein-Barr virus (EBV) has long been suggested as a pathogen in multiple sclerosis (MS). Here, we used high-throughput sequencing to determine the diversity, compartmentalization, persistence, and EBV-reactivity of the T-cell receptor (TCR) repertoires in MS. TCR-β genes were sequenced in paired samples of cerebrospinal fluid (CSF) and blood from patients with MS and controls with other inflammatory neurological diseases. The TCR repertoires were highly diverse in both compartments and patient groups. Expanded T-cell clones, represented by TCR-β sequences >0.1%, were of different identity in CSF and blood of MS patients, and persisted for more than a year. Reference TCR-β libraries generated from peripheral blood T cells reactive against autologous EBV-transformed B cells were highly enriched for public EBV-specific sequences and were used to quantify EBV-reactive TCR-β sequences in CSF. TCR-β sequences of EBV-reactive CD8+ T cells, including several public EBV-specific sequences, were intrathecally enriched in MS patients only, whereas those of EBV-reactive CD4+ T cells were also enriched in CSF of controls. These data provide evidence for a clonally diverse, yet compartmentalized and persistent, intrathecal T-cell response in MS. The presented strategy links TCR sequence to intrathecal T-cell specificity, demonstrating enrichment of EBV-reactive CD8+ T cells in MS. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of permissive hypotension, hypertonic resuscitation and the global increased permeability syndrome in patients with severe hemorrhage: adjuncts to damage control resuscitation to prevent intra-abdominal hypertension.

PubMed

Duchesne, Juan C; Kaplan, Lewis J; Balogh, Zsolt J; Malbrain, Manu L N G

2015-01-01

Secondary intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are closely related to fluid resuscitation. IAH causes major deterioration of the cardiac function by affecting preload, contractility and afterload. The aim of this review is to discuss the different interactions between IAH, ACS and resuscitation, and to explore a new hypothesis with regard to damage control resuscitation, permissive hypotension and global increased permeability syndrome. Review of the relevant literature via PubMed search. The recognition of the association between the development of ACS and resuscitation urged the need for new approach in traumatic shock management. Over a decade after wide spread application of damage control surgery damage control resuscitation was developed. DCR differs from previous resuscitation approaches by attempting an earlier and more aggressive correction of coagulopathy, as well as metabolic derangements like acidosis and hypothermia, often referred to as the 'deadly triad' or the 'bloody vicious cycle'. Permissive hypotension involves keeping the blood pressure low enough to avoid exacerbating uncontrolled haemorrhage while maintaining perfusion to vital end organs. The potential detrimental mechanisms of early, aggressive crystalloid resuscitation have been described. Limitation of fluid intake by using colloids, hypertonic saline (HTS) or hyperoncotic albumin solutions have been associated with favourable effects. HTS allows not only for rapid restoration of circulating intravascular volume with less administered fluid, but also attenuates post-injury oedema at the microcirculatory level and may improve microvascular perfusion. Capillary leak represents the maladaptive, often excessive, and undesirable loss of fluid and electrolytes with or without protein into the interstitium that generates oedema. The global increased permeability syndrome (GIPS) has been articulated in patients with persistent systemic inflammation failing to curtail transcapillary albumin leakage and resulting in increasingly positive net fluid balances. GIPS may represent a third hit after the initial insult and the ischaemia reperfusion injury. Novel markers like the capillary leak index, extravascular lung water and pulmonary permeability index may help the clinician in guiding appropriate fluid management. Capillary leak is an inflammatory condition with diverse triggers that results from a common pathway that includes ischaemia-reperfusion, toxic oxygen metabolite generation, cell wall and enzyme injury leading to a loss of capillary endothelial barrier function. Fluid overload should be avoided in this setting.

No calcium-fluoride-like deposits detected in plaque shortly after a sodium fluoride mouthrinse.

PubMed

Vogel, G L; Tenuta, L M A; Schumacher, G E; Chow, L C

2010-01-01

Plaque 'calcium-fluoride-like' (CaF(2)-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 microg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF(2)-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF(2)-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF(2)-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF(2)-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF(2)-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses. (c) 2010 S. Karger AG, Basel.

Fluid-faulting evolution in high definition: Connecting fault structure and frequency-magnitude variations during the 2014 Long Valley Caldera, California earthquake swarm

USGS Publications Warehouse

Shelly, David R.; Ellsworth, William L.; Hill, David P.

2016-01-01

An extended earthquake swarm occurred beneath southeastern Long Valley Caldera between May and November 2014, culminating in three magnitude 3.5 earthquakes and 1145 cataloged events on 26 September alone. The swarm produced the most prolific seismicity in the caldera since a major unrest episode in 1997-1998. To gain insight into the physics controlling swarm evolution, we used large-scale cross-correlation between waveforms of cataloged earthquakes and continuous data, producing precise locations for 8494 events, more than 2.5 times the routine catalog. We also estimated magnitudes for 18,634 events (~5.5 times the routine catalog), using a principal component fit to measure waveform amplitudes relative to cataloged events. This expanded and relocated catalog reveals multiple episodes of pronounced hypocenter expansion and migration on a collection of neighboring faults. Given the rapid migration and alignment of hypocenters on narrow faults, we infer that activity was initiated and sustained by an evolving fluid pressure transient with a low-viscosity fluid, likely composed primarily of water and CO2 exsolved from underlying magma. Although both updip and downdip migration were observed within the swarm, downdip activity ceased shortly after activation, while updip activity persisted for weeks at moderate levels. Strongly migrating, single-fault episodes within the larger swarm exhibited a higher proportion of larger earthquakes (lower Gutenberg-Richter b value), which may have been facilitated by fluid pressure confined in two dimensions within the fault zone. In contrast, the later swarm activity occurred on an increasingly diffuse collection of smaller faults, with a much higher b value.

No Calcium-Fluoride-Like Deposits Detected in Plaque Shortly after a Sodium Fluoride Mouthrinse

PubMed Central

Vogel, G.L.; Tenuta, L.M.A.; Schumacher, G.E.; Chow, L.C.

2010-01-01

Plaque ‘calcium-fluoride-like’ (CaF2-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 μg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF2-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF2-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF2-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF2-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF2-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses. PMID:20185917

Experimental degradation of polymer shopping bags (standard and degradable plastic, and biodegradable) in the gastrointestinal fluids of sea turtles.

PubMed

Müller, Christin; Townsend, Kathy; Matschullat, Jörg

2012-02-01

The persistence of marine debris such as discarded polymer bags has become globally an increasing hazard to marine life. To date, over 177 marine species have been recorded to ingest man-made polymers that cause life-threatening complications such as gut impaction and perforation. This study set out to test the decay characteristics of three common types of shopping bag polymers in sea turtle gastrointestinal fluids (GIF): standard and degradable plastic, and biodegradable. Fluids were obtained from the stomachs, small intestines and large intestines of a freshly dead Green turtle (Chelonia mydas) and a Loggerhead turtle (Caretta caretta). Controls were carried out with salt and freshwater. The degradation rate was measured over 49 days, based on mass loss. Degradation rates of the standard and the degradable plastic bags after 49 days across all treatments and controls were negligible. The biodegradable bags showed mass losses between 3 and 9%. This was a much slower rate than reported by the manufacturers in an industrial composting situation (100% in 49 days). The GIF of the herbivorous Green turtle showed an increased capacity to break down the biodegradable polymer relative to the carnivorous Loggerhead, but at a much lower rate than digestion of natural vegetative matter. While the breakdown rate of biodegradable polymers in the intestinal fluids of sea turtles is greater than standard and degradable plastics, it is proposed that this is not rapid enough to prevent morbidity. Further study is recommended to investigate the speed at which biodegradable polymers decompose outside of industrial composting situations, and their durability in marine and freshwater systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Diagnosis of Persistent Infection in Prosthetic Two-Stage Exchange: Evaluation of the Effect of Sonication on Antibiotic Release from Bone Cement Spacers.

PubMed

Mariaux, Sandrine; Furustrand Tafin, Ulrika; Borens, Olivier

2018-01-01

Introduction : When treating periprosthetic joint infection with a two-stage procedure, antibiotic-impregnated spacers can be used in the interval between prosthetic removal and reimplantation. In our experience, cultures of sonicated spacers are most often negative. The objective of the study was to assess whether that sonication causes an elution of antibiotics, leading to elevated antibiotic concentrations in the sonication fluid inhibiting bacterial growth and thus causing false-negative cultures. Methods : A prospective monocentric study was performed from September 2014 to March 2016. Inclusion criteria were a two-stage procedure for prosthetic infection and agreement of the patient to participate in the study. Spacers were made of gentamicin-containing cement to which tobramycin and vancomycin were added. Antibiotic concentrations in the sonication fluid were determined by mass-spectometry (LC-MS). Results : 30 patients were identified (15 hip and 14 knee and 1 ankle arthroplasties). No cases of culture positive sonicated spacer fluid were observed in our serie. In the sonication fluid median concentrations of 13.2µg/ml, 392 µg/ml and 16.6 µg/ml were detected for vancomycin, tobramycin and gentamicin, respectively. According to the European Committee on antimicrobial susceptibility testing (EUCAST), these concentrations released from cement spacer during sonication are higher than the minimal inhibitory concentrations (MICs) for most bacteria relevant in prosthetic joint infections. Conclusion: Spacer sonication cultures remained sterile in all of our cases. Elevated concentrations of antibiotics released during sonication could explain partly negative-cultured sonicated spacers. Indeed, the absence of antibiotic free interval during the two-stages can also contribute to false-negative spacers sonicated cultures.

Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water

PubMed Central

Gallandat, Karin; Daniels, Kyle; Desmarais, Anne Marie; Scheinman, Pamela; Lantagne, Daniele

2017-01-01

To prevent Ebola transmission, frequent handwashing is recommended in Ebola Treatment Units and communities. However, little is known about which handwashing protocol is most efficacious. We evaluated six handwashing protocols (soap and water, alcohol-based hand sanitizer (ABHS), and 0.05% sodium dichloroisocyanurate, high-test hypochlorite, and stabilized and non-stabilized sodium hypochlorite solutions) for 1) efficacy of handwashing on the removal and inactivation of non-pathogenic model organisms and, 2) persistence of organisms in rinse water. Model organisms E. coli and bacteriophage Phi6 were used to evaluate handwashing with and without organic load added to simulate bodily fluids. Hands were inoculated with test organisms, washed, and rinsed using a glove juice method to retrieve remaining organisms. Impact was estimated by comparing the log reduction in organisms after handwashing to the log reduction without handwashing. Rinse water was collected to test for persistence of organisms. Handwashing resulted in a 1.94–3.01 log reduction in E. coli concentration without, and 2.18–3.34 with, soil load; and a 2.44–3.06 log reduction in Phi6 without, and 2.71–3.69 with, soil load. HTH performed most consistently well, with significantly greater log reductions than other handwashing protocols in three models. However, the magnitude of handwashing efficacy differences was small, suggesting protocols are similarly efficacious. Rinse water demonstrated a 0.28–4.77 log reduction in remaining E. coli without, and 0.21–4.49 with, soil load and a 1.26–2.02 log reduction in Phi6 without, and 1.30–2.20 with, soil load. Chlorine resulted in significantly less persistence of E. coli in both conditions and Phi6 without soil load in rinse water (p<0.001). Thus, chlorine-based methods may offer a benefit of reducing persistence in rinse water. We recommend responders use the most practical handwashing method to ensure hand hygiene in Ebola contexts, considering the potential benefit of chlorine-based methods in rinse water persistence. PMID:28231311

Genomic Evidence of Chemotrophic Metabolisms in Deep-Dwelling Chloroflexi Conferred by Ancient Horizontal Gene Transfer Events

NASA Astrophysics Data System (ADS)

Momper, L. M.; Magnabosco, C.; Amend, J.; Osburn, M. R.; Fournier, G. P.

2017-12-01

The marine and terrestrial subsurface biospheres represent quite likely the largest reservoirs for life on Earth, directly impacting surface processes and global cycles throughout Earth's history. In the deep subsurface biosphere (DSB) organic carbon and energy are often extremely scarce. However, archaea and bacteria are able to persist in the DSB to at least 3.5 km below surface [1]. Understanding how they persist, and by what metabolisms they subsist, are key questions in this biosphere. To address these questions we investigated 5 global DSB environments: one legacy mine in South Dakota, USA, 3 mines in South Africa and marine fluids circulating beneath the Juan de Fuca Ridge. Boreholes within these mines provided access to fluids buried beneath the earth's surface and sampled depths down to 3.1 km. Geochemical data were collected concomitantly with DNA for metagenomic sequencing. We examined genomes of the ancient and deeply branching Chloroflexi for metabolic capabilities and interrogated the geochemical drivers behind those metabolisms with in situ thermodynamic modeling of reaction energetics. In total, 23 Chloroflexi genomes were identified and analyzed from the 5 subsurface sites. Genes for nitrate reduction (nar) and sulfite reduction (dsr) were found in many of the South Africa Chloroflexi but were absent from genomes collected in South Dakota. Indeed, nitrate reduction was among the most energetically favorable reactions in South African fluids (10-14 kJ cell-1 sec -1 per mol of reactant) and sulfur reduction with Fe2+ or H2 was also exergonic [2]. Conversely, genes for nitrite and nitrous oxide reduction (nrf, nir and nos) were found in genomes collected in South Dakota and Juan de Fuca, but not South Africa. We examined the origin of genes conferring these metabolisms in the Chloroflexi genomes. We discovered evidence for horizontal gene transfer (HGT) for all of these putative metabolisms. Retention of these genes in Chloroflexi lineages indicates HGT may have conferred an advantageous metabolism in DSB environments. We are using molecular dating techniques to constrain the timing of these HGT events on geologic timescales. [1] Baker J. B. et al. (2003) Environ Microbiol., 5, 267-277. [2] Magnabosco C. et al. (2016) ISME J, 10(3), 730-741.

Endoscopic third ventriculostomy and posterior fossa tumors.

PubMed

Di Rocco, Federico; Jucá, Carlos Eduardo; Zerah, Michel; Sainte-Rose, Christian

2013-02-01

The management of hydrocephalus associated with a posterior fossa tumor is debated. Some authors emphasize the advantages of an immediate tumor removal that may normalize the cerebrospinal fluid (CSF) dynamics. However, in clinical practice, the mere excision of the lesion has been demonstrated to be accompanied by a persisting hydrocephalus in about one third of the cases. Preoperative endoscopic third ventriculostomy (ETV) offers several advantages. It may control the intracranial pressure (ICP), avoid the necessity of an emergency procedure, allow appropriate scheduling of the operation for tumor removal, and eliminate the risks related to the presence of an external drainage. The procedure also reduces the incidence of postoperative hydrocephalus. A final advantage, more difficult to weight, but obvious to the neurosurgeon, is the possibility to remove the lesion with a relaxed brain and normal ICP. In the postoperative phase, ETV can be used in case of persisting hydrocephalus, both in patients who underwent only the excision of the tumor and in those whose preoperative ETV failed as a consequence of intraventricular bleeding with secondary closure of the stoma (redoETV). The main advantage of postoperative ETV is that the procedure is carried out only in case of persisting hydrocephalus; its use is consequently more selective than preoperative ETV. The disadvantage consists in the common use of an external CSF drainage in the first few postoperative days, which is necessary to control the pressure and for ruling out those cases that reach a spontaneous cure of the hydrocephalus. The authors review the criteria for patient selection and the results of ETV performed in case of hydrocephalus secondary to a posterior fossa tumor. Preoperative ETV constitutes an effective procedure for controlling the hydrocephalus associated with posterior fossa tumors. It might lower the rate of persistent postoperative hydrocephalus and result in a short hospital stay. Low rates of patients requiring an extrathecal-CSF shunt device are also reported by authors who utilize ETV postoperatively. As, however, the assessment of the persistent hydrocephalus in these children is based on prolonged ICP monitoring through an external CSF drainage, their results are weighted by a major risk of infective complications and longer hospital stay. Copyright © 2013 Elsevier Inc. All rights reserved.

The physics of debris flows

NASA Astrophysics Data System (ADS)

Iverson, Richard M.

1997-08-01

Recent advances in theory and experimentation motivate a thorough reassessment of the physics of debris flows. Analyses of flows of dry, granular solids and solid-fluid mixtures provide a foundation for a comprehensive debris flow theory, and experiments provide data that reveal the strengths and limitations of theoretical models. Both debris flow materials and dry granular materials can sustain shear stresses while remaining static; both can deform in a slow, tranquil mode characterized by enduring, frictional grain contacts; and both can flow in a more rapid, agitated mode characterized by brief, inelastic grain collisions. In debris flows, however, pore fluid that is highly viscous and nearly incompressible, composed of water with suspended silt and clay, can strongly mediate intergranular friction and collisions. Grain friction, grain collisions, and viscous fluid flow may transfer significant momentum simultaneously. Both the vibrational kinetic energy of solid grains (measured by a quantity termed the granular temperature) and the pressure of the intervening pore fluid facilitate motion of grains past one another, thereby enhancing debris flow mobility. Granular temperature arises from conversion of flow translational energy to grain vibrational energy, a process that depends on shear rates, grain properties, boundary conditions, and the ambient fluid viscosity and pressure. Pore fluid pressures that exceed static equilibrium pressures result from local or global debris contraction. Like larger, natural debris flows, experimental debris flows of ˜10 m³ of poorly sorted, water-saturated sediment invariably move as an unsteady surge or series of surges. Measurements at the base of experimental flows show that coarse-grained surge fronts have little or no pore fluid pressure. In contrast, finer-grained, thoroughly saturated debris behind surge fronts is nearly liquefied by high pore pressure, which persists owing to the great compressibility and moderate permeability of the debris. Realistic models of debris flows therefore require equations that simulate inertial motion of surges in which high-resistance fronts dominated by solid forces impede the motion of low-resistance tails more strongly influenced by fluid forces. Furthermore, because debris flows characteristically originate as nearly rigid sediment masses, transform at least partly to liquefied flows, and then transform again to nearly rigid deposits, acceptable models must simulate an evolution of material behavior without invoking preternatural changes in material properties. A simple model that satisfies most of these criteria uses depth-averaged equations of motion patterned after those of the Savage-Hutter theory for gravity-driven flow of dry granular masses but generalized to include the effects of viscous pore fluid with varying pressure. These equations can describe a spectrum of debris flow behaviors intermediate between those of wet rock avalanches and sediment-laden water floods. With appropriate pore pressure distributions the equations yield numerical solutions that successfully predict unsteady, nonuniform motion of experimental debris flows.

The physics of debris flows

USGS Publications Warehouse

Iverson, R.M.

1997-01-01

Recent advances in theory and experimentation motivate a thorough reassessment of the physics of debris flows. Analyses of flows of dry, granular solids and solid-fluid mixtures provide a foundation for a comprehensive debris flow theory, and experiments provide data that reveal the strengths and limitations of theoretical models. Both debris flow materials and dry granular materials can sustain shear stresses while remaining static; both can deform in a slow, tranquil mode characterized by enduring, frictional grain contacts; and both can flow in a more rapid, agitated mode characterized by brief, inelastic grain collisions. In debris flows, however, pore fluid that is highly viscous and nearly incompressible, composed of water with suspended silt and clay, can strongly mediate intergranular friction and collisions. Grain friction, grain collisions, and viscous fluid flow may transfer significant momentum simultaneously. Both the vibrational kinetic energy of solid grains (measured by a quantity termed the granular temperature) and the pressure of the intervening pore fluid facilitate motion of grains past one another, thereby enhancing debris flow mobility. Granular temperature arises from conversion of flow translational energy to grain vibrational energy, a process that depends on shear rates, grain properties, boundary conditions, and the ambient fluid viscosity and pressure. Pore fluid pressures that exceed static equilibrium pressures result from local or global debris contraction. Like larger, natural debris flows, experimental debris flows of ???10 m3 of poorly sorted, water-saturated sediment invariably move as an unsteady surge or series of surges. Measurements at the base of experimental flows show that coarse-grained surge fronts have little or no pore fluid pressure. In contrast, finer-grained, thoroughly saturated debris behind surge fronts is nearly liquefied by high pore pressure, which persists owing to the great compressibility and moderate permeability of the debris. Realistic models of debris flows therefore require equations that simulate inertial motion of surges in which high-resistance fronts dominated by solid forces impede the motion of low-resistance tails more strongly influenced by fluid forces. Furthermore, because debris flows characteristically originate as nearly rigid sediment masses, transform at least partly to liquefied flows, and then transform again to nearly rigid deposits, acceptable models must simulate an evolution of material behavior without invoking preternatural changes in material properties. A simple model that satisfies most of these criteria uses depth-averaged equations of motion patterned after those of the Savage-Hutter theory for gravity-driven flow of dry granular masses but generalized to include the effects of viscous pore fluid with varying pressure. These equations can describe a spectrum of debris flow behaviors intermediate between those of wet rock avalanches and sediment-laden water floods. With appropriate pore pressure distributions the equations yield numerical solutions that successfully predict unsteady, nonuniform motion of experimental debris flows.

Hypothermia as a cause of coagulopathy during hepatectomy.

PubMed

Lau, Albert Wai-Cheung; Chen, Chia-Chen; Wu, Rick Sai-Chuen; Poon, Kin-Shing

2010-06-01

We report a 27-year-old hemostatically competent female scheduled for partial hepatectomy. During the operation, she experienced an accidental inferior vena cava tear and suffered acute blood loss. After fluid resuscitation and blood transfusion, she developed hypothermia, with a temperature of 33.8 degrees C, and severe coagulopathy with activated clotting time exceeding 1500 seconds measured using the Hemochron Response system (ITC, Edison, NJ, USA). Despite sufficient blood transfusion and correction of her electrolyte imbalance, the poor hemostasis persisted. After per-forming peritoneal lavage with warm saline, her condition dramatically improved and her hypothermia and severe coagulopathy were reversed. 2010 Taiwan Society of Anesthesiologists. Published by Elsevier B.V. All rights reserved.

Global Regularity of 2D Density Patches for Inhomogeneous Navier-Stokes

NASA Astrophysics Data System (ADS)

Gancedo, Francisco; García-Juárez, Eduardo

2018-07-01

This paper is about Lions' open problem on density patches (Lions in Mathematical topics in fluid mechanics. Vol. 1, volume 3 of Oxford Lecture series in mathematics and its applications, Clarendon Press, Oxford University Press, New York, 1996): whether or not inhomogeneous incompressible Navier-Stokes equations preserve the initial regularity of the free boundary given by density patches. Using classical Sobolev spaces for the velocity, we first establish the propagation of {C^{1+γ}} regularity with {0 < γ < 1} in the case of positive density. Furthermore, we go beyond this to show the persistence of a geometrical quantity such as the curvature. In addition, we obtain a proof for {C^{2+γ}} regularity.

Ultrastructural blood-brain barrier alterations and edema formation in acute spinal cord trauma.

PubMed

Goodman, J H; Bingham, W G; Hunt, W E

1976-04-01

Endothelial changes leading to edema formation are examined in the primate spinal cord (Macaca mulatta) following a lesion created by a 20-gm weight falling 15 cm onto the exposed dura. Intravascular perfusion of a paraformaldehydeglutaraldehyde solution followed by carbon black provides adequate fixation of vascular structures and glial elements. Myelin is poorly preserved. Ultrastructural alterations of the blood-brain barrier consist of loss of integrity of the endothelial tight junctions. Edema caused by vascular disruption and parenchymatous extravasation of intravascular contents is observed along with glial swelling. Interglial gap junctions persist in areas of marked cellular seperation and do not impede the migration of edema fluid.

Bioconvection and front formation of Paramecium tetraurelia

NASA Astrophysics Data System (ADS)

Kitsunezaki, So; Komori, Rie; Harumoto, Terue

2007-10-01

We have investigated the bioconvection of Paramecium tetraurelia in high-density suspensions made by centrifugal concentration. When a suspension is kept at rest in a Hele-Shaw cell, a crowded front of paramecia is formed in the vicinity of the bottom and it propagates gradually toward the water-air interface. Fluid convection occurs under this front, and it is driven persistently by the upward swimming of paramecia. The roll structures of the bioconvection become turbulent with an increase in the depth of the suspension; they also change rapidly as the density of paramecia increases. Our experimental results suggest that lack of oxygen in the suspension causes the active individual motions of paramecia to induce the formation of this front.

Breast Cancer Metastasis to the Stomach That Was Diagnosed after Endoscopic Submucosal Dissection.

PubMed

Kita, Masahide; Furukawa, Masashi; Iwamuro, Masaya; Hori, Keisuke; Kawahara, Yoshiro; Taira, Naruto; Nogami, Tomohiro; Shien, Tadahiko; Tanaka, Takehiro; Doihara, Hiroyoshi; Okada, Hiroyuki

2016-01-01

A 52-year-old woman presented with stage IIB primary breast cancer (cT2N1M0), which was treated using neoadjuvant chemotherapy (epirubicin, cyclophosphamide, and paclitaxel). However, the tumor persisted in patchy areas; therefore, we performed modified radical mastectomy and axillary lymph node dissection. Routine endoscopy at 8 months revealed a depressed lesion on the gastric angle's greater curvature, and histology revealed signet ring cell proliferation. We performed endoscopic submucosal dissection for gastric cancer, although immunohistochemistry revealed that the tumor was positive for estrogen receptor, mammaglobin, and gross cystic disease fluid protein-15 (E-cadherin-negative). Therefore, we revised the diagnosis to gastric metastasis from the breast cancer.

Hypertensive choroidopathy in pre-eclampsia: two consecutive cases.

PubMed

Dewilde, Evelien; Huygens, Marc; Cools, Geertrui; Van Calster, Joachim

2014-01-01

Hypertensive retinopathy is well known, but choroidopathy is uncommon and associated with acute increases in blood pressure. Nonperfused areas of the choriocapillaris lead to changes of overlying retinal pigment epithelium (RPE), resulting in neurosensory or RPE detachments. The authors describe two patients with serous retinal detachments associated with acute arterial hypertension in pre-eclampsia and HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome. Subretinal fluid was demonstrated on ultra-widefield fundus imaging and optical coherence tomography. Fluorescein angiography and indocyanine green angiography enabled imaging of the choroidal hypoperfusion. All signs and symptoms resolved after 1 and 3 months, respectively, with persistent macular pigmentary changes in both patients. Copyright 2014, SLACK Incorporated.

Seismicity remotely triggered by the magnitude 7.3 landers, california, earthquake

USGS Publications Warehouse

Hill, D.P.; Reasenberg, P.A.; Michael, A.; Arabaz, W.J.; Beroza, G.; Brumbaugh, D.; Brune, J.N.; Castro, R.; Davis, S.; Depolo, D.; Ellsworth, W.L.; Gomberg, J.; Harmsen, S.; House, L.; Jackson, S.M.; Johnston, M.J.S.; Jones, L.; Keller, Rebecca Hylton; Malone, S.; Munguia, L.; Nava, S.; Pechmann, J.C.; Sanford, A.; Simpson, R.W.; Smith, R.B.; Stark, M.; Stickney, M.; Vidal, A.; Walter, S.; Wong, V.; Zollweg, J.

1993-01-01

The magnitude 7.3 Landers earthquake of 28 June 1992 triggered a remarkably sudden and widespread increase in earthquake activity across much of the western United States. The triggered earthquakes, which occurred at distances up to 1250 kilometers (17 source dimensions) from the Landers mainshock, were confined to areas of persistent seismicity and strike-slip to normal faulting. Many of the triggered areas also are sites of geothermal and recent volcanic activity. Static stress changes calculated for elastic models of the earthquake appear to be too small to have caused the triggering. The most promising explanations involve nonlinear interactions between large dynamic strains accompanying seismic waves from the mainshock and crustal fluids (perhaps including crustal magma).

Subsidence at Kiska volcano, Western Aleutians, detected by satellite radar interferometry

USGS Publications Warehouse

Lu, Z.; Masterlark, Timothy; Power, J.; Dzurisin, D.; Wicks, Charles

2002-01-01

Sequential interferometric synthetic aperture radar images of Kiska, the westernmost historically active volcano in the Aleutian arc, show that a circular area about 3 km in diameter centered near the summit subsided by as much as 10 cm from 1995 to 2001, mostly during 1999 and 2000. An elastic Mogi-type deformation model suggests that the source is within 1 km of the surface. Based on the shallow source depth, the copious amounts of steam during recent eruptions, and recent field reports of vigorous steaming and persistent ground shaking near the summit area, we attribute the subsidence to decreased pore-fluid pressure within a shallow hydrothermal system beneath the summit area.

Orbeez: the magic water absorbing bead--risk of pediatric bowel obstruction?

PubMed

Darracq, Michael A; Cullen, Jennifer; Rentmeester, Landen; Cantrell, F Lee; Ly, Binh T

2015-06-01

In December 2012, the U.S. Consumer Product Safety Commission recalled the water-absorbing toy WaterBalz after reports of small intestine obstruction after ingestion by children. Orbeez, another water-absorbing bead, remains available and is marketed as a children's toy. We sought to determine the extent to which Orbeez enlarge in various liquid media and the potential risk for bowel obstruction. Three Orbeez beads were added to 210 mL of the following liquid media: room temperature tap water, whole milk, simulated gastric fluid, GoLytely (polyethelyelene glycol, 3350 and electrolytes), and vodka (40% ethanol by volume). Diameters before exposure to media were measured using a caliper to the nearest 0.1 mm and again at 1, 2, 4, 6, 12, and 24 hours. Ten beads were then added to the beads already immersed in simulated gastric fluid and water and observed for an additional 72 hours (96 hours total) for clumping or increase in diameter. Clumping was defined as two or more beads remaining persistently adherent to one another despite gentle circular movement (swirling) of the liquid. Growth in each of the media was observed. Growth in simulated gastric fluid was minimal, whereas the beads were observed to be the largest after 24 hours in vodka. Clumping of the beads was not observed to occur. Orbeez beads enlarge to a different extent in different liquid media. It is unlikely that Orbeez beads would expand to sizes or demonstrate clumping that would be concerning for intestinal obstruction.

Blunt pancreatic trauma: A persistent diagnostic conundrum?

PubMed Central

Kumar, Atin; Panda, Ananya; Gamanagatti, Shivanand

2016-01-01

Blunt pancreatic trauma is an uncommon injury but has high morbidity and mortality. In modern era of trauma care, pancreatic trauma remains a persistent challenge to radiologists and surgeons alike. Early detection of pancreatic trauma is essential to prevent subsequent complications. However early pancreatic injury is often subtle on computed tomography (CT) and can be missed unless specifically looked for. Signs of pancreatic injury on CT include laceration, transection, bulky pancreas, heterogeneous enhancement, peripancreatic fluid and signs of pancreatitis. Pan-creatic ductal injury is a vital decision-making parameter as ductal injury is an indication for laparotomy. While lacerations involving more than half of pancreatic parenchyma are suggestive of ductal injury on CT, ductal injuries can be directly assessed on magnetic resonance imaging (MRI) or encoscopic retrograde cholangio-pancreatography. Pancreatic trauma also shows temporal evolution with increase in extent of injury with time. Hence early CT scans may underestimate the extent of injures and sequential imaging with CT or MRI is important in pancreatic trauma. Sequential imaging is also needed for successful non-operative management of pancreatic injury. Accurate early detection on initial CT and adopting a multimodality and sequential imaging strategy can improve outcome in pancreatic trauma. PMID:26981225

Unconventional Management of Chyloascites After Laparoscopic Nissen Fundoplication

PubMed Central

Ospina, Karen A.; Lee, Earl H.; Rehring, Scott R.

2012-01-01

Background & Objectives: Chyloascites is a rare complication that can result from abdominal trauma, neoplasm, inflammatory conditions, or various abdominal surgeries. Few cases have been described secondary to iatrogenic injury from laparoscopic Nissen fundoplication. We describe a case in which this surgery resulted in chyloascites that was successfully treated by lymphatic glue embolization. Methods: A 37-year-old male presented with signs and symptoms consistent with chronic reflux disease. He underwent an uneventful laparoscopic Nissen fundoplication. Two weeks postoperatively, he was admitted for dehydration. During his admission, he began to develop a persistent cough, shortness of breath, and abdominal distention. Imaging and fluid analysis from thoracocentesis and paracentesis were consistent with chyle leakage. Despite nonoperative measures, the patient's presentation persisted. Results: Thoracic duct ligation was performed without success. Bipedal lymphangiography identified an extensive leak revealing a severely lacerated thoracic duct spilling contrast freely into the abdomen and no contrast entering the thoracic duct in the chest. The site of injury was successfully sealed off with percutaneous glue embolization through lymph channels. Conclusion: Chyloascites is a rare complication of laparoscopic Nissen fundoplication. When not successful with conservative measures, lymphatic glue embolization can provide effective treatment. PMID:23477184

Attempts to revive Mycobacterium tuberculosis from 300-year-old human mummies.

PubMed

Lemma, Eshetu; Zimhony, Oren; Greenblatt, Charles L; Koltunov, Viktoria; Zylber, María Inés; Vernon, Kim; Spigelman, Mark

2008-06-01

Environmental persistence of Mycobacterium tuberculosis is subject to speculation. However, the reality that infected postmortem tissues can be a danger to pathologists and embalmers has worrisome implications. A few experimental studies have demonstrated the organism's ability to withstand exposure to embalming fluid and formalin. Recently, a failure was reported in an attempt to resuscitate an original isolate of Robert Koch to determine the lifetime of the tubercle bacillus. The present study also considers a historical approach to determine persistence under favorable environmental conditions. It asks whether acid-fast forms observed in tissues of 300-year-old Hungarian mummies can be resuscitated. Finding organisms before the advent of antibiotics and pasteurization may yield valuable genetic information. Using various media modifications, as well as guinea pig inoculation, an attempt was made to culture these tissues for M. tuberculosis. In addition, a resuscitation-promoting factor, known to increase colony counts in high G+C bacteria, was applied to the cultures. Although an occasional PCR-positive sample was detected, no colonies of M. tuberculosis were obtained. Our results may indicate that the life span of the tubercle bacillus is less than a few hundred years, even though in the short run it can survive harsh chemical treatment.

CD-loop Extension in Zika Virus Envelope Protein Key for Stability and Pathogenesis.

PubMed

Gallichotte, Emily N; Dinnon, Kenneth H; Lim, Xin-Ni; Ng, Thiam-Seng; Lim, Elisa X Y; Menachery, Vineet D; Lok, Shee-Mei; Baric, Ralph S

2017-12-05

With severe disease manifestations including microcephaly, congenital malformation, and Guillain-Barré syndrome, Zika virus (ZIKV) remains a persistent global public health threat. Despite antigenic similarities with dengue viruses, structural studies have suggested the extended CD-loop and hydrogen-bonding interaction network within the ZIKV envelope protein contribute to stability differences between the viral families. This enhanced stability may lead to the augmented infection, disease manifestation, and persistence in body fluids seen following ZIKV infection. To examine the role of these motifs in infection, we generated a series of ZIKV recombinant viruses that disrupted the hydrogen-bonding network (350A, 351A, and 350A/351A) or the CD-loop extension (Δ346). Our results demonstrate a key role for the ZIKV extended CD-loop in cell-type-dependent replication, virion stability, and in vivo pathogenesis. Importantly, the Δ346 mutant maintains similar antigenicity to wild-type virus, opening the possibility for its use as a live-attenuated vaccine platform for ZIKV and other clinically relevant flaviviruses. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Detection and quantification of pestivirus in experimentally infected pregnant ewes and their progeny.

PubMed

Hurtado, Ana; Sanchez, Isbene; Bastida, Felix; Minguijón, Esmeralda; Juste, Ramón A; García-Pérez, Ana L

2009-11-05

Border disease virus (BDV) causes important reproductive losses, and eradication strategies focus on the identification and removal of persistently infected animals arising after in uterine infection. BDV infection dynamics were studied in 13 ewes experimentally infected with BDV-4 genotype at 3 phases of pregnancy [days 108 (group A), 76 (group B) and 55 (group C)] by quantification of viral RNA in blood collected on days -1 to parturition using quantitative real-time RT-PCR (qRT-PCR). Viral RNA loads were also measured in blood/foetal fluid and tissue samples from their offspring at lambing (3 foetuses, 7 stillborns, 15 lambs). qRT-PCR results were compared with those obtained by conventional RT-PCR and used to predict persistent infections. Viral RNA was detected in the ewes between days 2-15 p.i. The viraemia reached its highest peak between days 6-7 p.i. with a second peak at days 11-12 p.i. qRT-PCR was significantly faster to perform (less than 1 h) than conventional RT-PCR and detected BDV RNA in more ewes, being detection more continuous and prolonged in time. The virus was detected in peripheral blood in a higher percentage of lambs than in tissues, where differences in viral genome copies were more marked. Skin and cerebral cortex showed the highest viral RNA loads, and spleen and spinal cord the lowest. High viral RNA loads were observed in several animals in group B and all in group C, infected during middle and early foetal development, respectively, but also in one lamb from group A, infected during late foetal development. Serology and viral genome copy number estimates in blood and tissues were used to establish a quantitative cut-off threshold for transient viraemia. Viral RNA quantification showed potential for the discrimination between persistent infections and transient viraemia using single-time point blood sampling and raised questions regarding foetal immune system development and the occurrence of persistent infections.

A phase I trial of intraperitoneal GEN-1, an IL-12 plasmid formulated with PEG-PEI-cholesterol lipopolymer, administered with pegylated liposomal doxorubicin in patients with recurrent or persistent epithelial ovarian, fallopian tube or primary peritoneal cancers: An NRG Oncology/Gynecologic Oncology Group study

PubMed Central

Thaker, Premal H.; Brady, William E.; Lankes, Heather A.; Odunsi, Kunle; Bradley, William H.; Moore, Kathleen N.; Muller, Carolyn Y.; Anwer, Khursheed; Schilder, Russell J.; Alvarez, Ronald D.; Fracasso, Paula M.

2017-01-01

Objective The study’s purpose was to assess safety and efficacy of escalating doses of weekly GEN-1 with pegylated liposomal doxorubicin (PLD) in patients with recurrent or persistent epithelial ovarian, fallopian tube or primary peritoneal cancers (EOC). Methods Patients had persistent or recurrent platinum-resistant EOC. The trial was a standard 3 + 3 phase I dose escalation design with patients receiving intravenous PLD 40 mg/m2 (dose level 1 and 2) or 50 mg/m2 (dose level 3) every 28 days and intraperitoneal GEN-1 at 24 mg/m2 (dose level 1) or 36 mg/m2 (dose level 2 and 3) on days 1, 8, 15, and 22 of a 28 day cycle. Cycles were repeated every 28 days until disease progression. Patients were monitored for toxicity, clinical efficacy, and evidence of systemic and intraperitoneal immunologic effect. Results Sixteen evaluable patients received a median of 4 cycles (range 1–8). No dose limiting toxicities were found. The adverse side effects were 4 grade 3 anemia, 2 grade 3 abdominal pain, 7 grade 3 neutropenia, and 2 grade 4 neutropenia. A clinical benefit of 57.1% (PR = 21.4%; SD = 35.7%) was found in the 14 patients with measurable disease. The highest number of partial responses (28.6%) and stable disease (57.1%) were found at dose level 3. The maximum tolerated dose was not reached. Increases in IL-12, IFN-γ, and TNF-α levels were found in peritoneal fluid following GEN-1 treatment. Conclusions GEN-1 in combination with PLD has encouraging clinical benefit and biological activity in recurrent or persistent EOC and warrants further investigation with escalating doses of GEN-1. PMID:28802766

Detecting the Influence of Initial Pioneers on Succession at Deep-Sea Vents

PubMed Central

Mullineaux, Lauren S.; Le Bris, Nadine; Mills, Susan W.; Henri, Pauline; Bayer, Skylar R.; Secrist, Richard G.; Siu, Nam

2012-01-01

Deep-sea hydrothermal vents are subject to major disturbances that alter the physical and chemical environment and eradicate the resident faunal communities. Vent fields are isolated by uninhabitable deep seafloor, so recolonization via dispersal of planktonic larvae is critical for persistence of populations. We monitored colonization near 9°50′N on the East Pacific Rise following a catastrophic eruption in order to address questions of the relative contributions of pioneer colonists and environmental change to variation in species composition, and the role of pioneers at the disturbed site in altering community structure elsewhere in the region. Pioneer colonists included two gastropod species: Ctenopelta porifera, which was new to the vent field, and Lepetodrilus tevnianus, which had been rare before the eruption but persisted in high abundance afterward, delaying and possibly out-competing the ubiquitous pre-eruption congener L. elevatus. A decrease in abundance of C. porifera over time, and the arrival of later species, corresponded to a decrease in vent fluid flow and in the sulfide to temperature ratio. For some species these successional changes were likely due to habitat requirements, but other species persisted (L. tevnianus) or arrived (L. elevatus) in patterns unrelated to their habitat preferences. After two years, disturbed communities had started to resemble pre-eruption ones, but were lower in diversity. When compared to a prior (1991) eruption, the succession of foundation species (tubeworms and mussels) appeared to be delayed, even though habitat chemistry became similar to the pre-eruption state more quickly. Surprisingly, a nearby community that had not been disturbed by the eruption was invaded by the pioneers, possibly after they became established in the disturbed vents. These results indicate that the post-eruption arrival of species from remote locales had a strong and persistent effect on communities at both disturbed and undisturbed vents. PMID:23226507

Persistent Homology fingerprinting of microstructural controls on larger-scale fluid flow in porous media

NASA Astrophysics Data System (ADS)

Moon, C.; Mitchell, S. A.; Callor, N.; Dewers, T. A.; Heath, J. E.; Yoon, H.; Conner, G. R.

2017-12-01

Traditional subsurface continuum multiphysics models include useful yet limiting geometrical assumptions: penny- or disc-shaped cracks, spherical or elliptical pores, bundles of capillary tubes, cubic law fracture permeability, etc. Each physics (flow, transport, mechanics) uses constitutive models with an increasing number of fit parameters that pertain to the microporous structure of the rock, but bear no inter-physics relationships or self-consistency. Recent advances in digital rock physics and pore-scale modeling link complex physics to detailed pore-level geometries, but measures for upscaling are somewhat unsatisfactory and come at a high computational cost. Continuum mechanics rely on a separation between small scale pore fluctuations and larger scale heterogeneity (and perhaps anisotropy), but this can break down (particularly for shales). Algebraic topology offers powerful mathematical tools for describing a local-to-global structure of shapes. Persistent homology, in particular, analyzes the dynamics of topological features and summarizes into numeric values. It offers a roadmap to both "fingerprint" topologies of pore structure and multiscale connectedness as well as links pore structure to physical behavior, thus potentially providing a means to relate the dependence of constitutive behaviors of pore structures in a self-consistent way. We present a persistence homology (PH) analysis framework of 3D image sets including a focused ion beam-scanning electron microscopy data set of the Selma Chalk. We extract structural characteristics of sampling volumes via persistence homology and fit a statistical model using the summarized values to estimate porosity, permeability, and connectivity—Lattice Boltzmann methods for single phase flow modeling are used to obtain the relationships. These PH methods allow for prediction of geophysical properties based on the geometry and connectivity in a computationally efficient way. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

Predictability and prediction of persistent cool states of the Tropical Pacific Ocean

NASA Astrophysics Data System (ADS)

Ramesh, Nandini; Cane, Mark A.; Seager, Richard; Lee, Dong Eun

2017-10-01

The Tropical Pacific Ocean displays persistently cool sea surface temperature (SST) anomalies that last several years to a decade, with either no El Niño events or a few weak El Niño events. These cause large-scale droughts in the extratropics, including major North American droughts such as the 1930s Dust Bowl, and also modulate the global mean surface temperature. Here we show that two models with different levels of complexity—the Zebiak-Cane intermediate model and the Geophysical Fluid Dynamics Laboratory Coupled Model version 2.1—are able to produce such periods in a realistic manner. We then test the predictability of these periods in the Zebiak-Cane model using an ensemble of experiments with perturbed initial states. Our results show that in most cases the cool mean state is predictable. We then apply this method to make retrospective forecasts of shifts in the decadal mean state and to forecast the mean state of the Tropical Pacific Ocean for the upcoming decade. Our results suggest that the Pacific will undergo a shift to a warmer mean state after the 2015-2016 El Niño. This could imply the cessation of the drier than normal conditions that have generally afflicted southwest North America since the 1997-1998 El Niño, as well as the twenty-first-century pause in global warming. Implications for our understanding of the origins of such persistent cool states and the possibility of improving predictions of large-scale droughts are discussed.

Perilymph pharmacokinetics of marker applied through a cochlear implant in guinea pigs

PubMed Central

Hartsock, Jared; Gill, Ruth; Smyth, Daniel; Kirk, Jonathon; Verhoeven, Kristien

2017-01-01

Patients undergoing cochlear implantation could benefit from a simultaneous application of drugs into the ear, helping preserve residual low-frequency hearing and afferent nerve fiber populations. One way to apply drugs is to incorporate a cannula into the implant, through which drug solution is driven. For such an approach, perilymph concentrations achieved and the distribution in the ear over time have not previously been documented. We used FITC-labeled dextran as a marker, delivering it into perilymph of guinea pigs at 10 or 100 nL/min though a cannula incorporated into a cochlear implant with the outlet in the mid basal turn. After injections of varying duration (2 hours, 1 day or 7 days) perilymph was collected from the cochlear apex using a sequential sampling technique, allowing dextran levels and gradients along scala tympani to be quantified. Data were interpreted quantitatively using computer simulations of the experiments. For injections of 2 hours duration, dextran levels were critically influenced by the presence or absence of fluid leakage at the cochleostomy site. When the cochleostomy was fluid-tight, substantially higher perilymph levels were achieved at the injection site, with concentration declining along scala tympani towards the apex. Contrary to expectations, large dextran gradients along scala tympani persisted after 24 hours of sustained injection and were still present in some animals after 7 days injection. Functional changes associated with implantation and dextran delivery, and the histological state of the implant and cannula were also documented. The persistent longitudinal gradients of dextan along the ear were not readily explained by computer simulations of the experiments based on prior pharmacokinetic data. One explanation is that inner ear pharmacokinetics are altered in the period after cochlear implantation, possibly by a permeabilization of the blood-labyrinth barrier as part of the immune response to the implant. PMID:28817653

Role of elevated plasma soluble ICAM-1 and bronchial lavage fluid IL-8 levels as markers of chronic lung disease in premature infants.

PubMed Central

Little, S.; Dean, T.; Bevin, S.; Hall, M.; Ashton, M.; Church, M.; Warner, J.; Shute, J.

1995-01-01

BACKGROUND--Pulmonary neutrophilia characterises both the relatively transient inflammation associated with infant respiratory distress syndrome (IRDS) and the persistent inflammation of chronic lung disease. The possibility that persistently raised markers of inflammation indicate the development of chronic lung disease in low birth weight (< 1730 g) preterm (< 31 weeks) infants was therefore investigated. METHODS--Soluble ICAM-1 (sICAM-1) levels in plasma, and interleukin (IL)-8 and myeloperoxidase (MPO) levels in bronchial lavage fluid (BLF) obtained from 17 infants on days 1, 5, and 14 following birth were measured and correlations with the number of neutrophils in BLF sought. Peripheral neutrophils were isolated on Polymorphoprep and chemotactic responsiveness to IL-8 was assessed using micro Boyden chambers. RESULTS--Sixteen infants developed IRDS and, of these, 10 infants subsequently developed chronic lung disease. Levels of IL-8 in BLF at 14 days of age correlated with the long term requirement for intermittent positive pressure ventilation (IPPV). Interleukin 8 levels in BLF correlated with neutrophil numbers and MPO concentration, suggesting both recruitment and activation in response to this cytokine. Antibody depletion studies showed that approximately 50% of total neutrophil chemotactic activity in BLF was due to IL-8. No difference in peripheral neutrophil chemotactic responsiveness at any age was observed for infants with IRDS or chronic lung disease. Plasma soluble intercellular adhesion molecule (sICAM-1) was higher at 14 days of age in infants who developed chronic lung disease than in those with resolving IRDS, and correlated with severity of disease, as indicated by duration of IPPV. CONCLUSIONS--The results indicate that high levels of plasma sICAM-1 and IL-8 in BLF at day 14 correlate with the development of chronic lung disease and indicate the severity of disease. PMID:7491556

Unstructured Grid Adaptation: Status, Potential Impacts, and Recommended Investments Toward CFD Vision 2030

NASA Technical Reports Server (NTRS)

Park, Michael A.; Krakos, Joshua A.; Michal, Todd; Loseille, Adrien; Alonso, Juan J.

2016-01-01

Unstructured grid adaptation is a powerful tool to control discretization error for Computational Fluid Dynamics (CFD). It has enabled key increases in the accuracy, automation, and capacity of some fluid simulation applications. Slotnick et al. provides a number of case studies in the CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences to illustrate the current state of CFD capability and capacity. The authors forecast the potential impact of emerging High Performance Computing (HPC) environments forecast in the year 2030 and identify that mesh generation and adaptivity continue to be significant bottlenecks in the CFD work flow. These bottlenecks may persist because very little government investment has been targeted in these areas. To motivate investment, the impacts of improved grid adaptation technologies are identified. The CFD Vision 2030 Study roadmap and anticipated capabilities in complementary disciplines are quoted to provide context for the progress made in grid adaptation in the past fifteen years, current status, and a forecast for the next fifteen years with recommended investments. These investments are specific to mesh adaptation and impact other aspects of the CFD process. Finally, a strategy is identified to diffuse grid adaptation technology into production CFD work flows.

Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography.

PubMed

Riddell, Nicole; Mullin, Lauren Gayle; van Bavel, Bert; Ericson Jogsten, Ingrid; McAlees, Alan; Brazeau, Allison; Synnott, Scott; Lough, Alan; McCrindle, Robert; Chittim, Brock

2016-11-10

Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+) and (-) enantiomers of α-, β-, and γ-HBCDD) were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC) separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC) methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD), was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

Falsification of Dark Energy by Fluid Mechanics

NASA Astrophysics Data System (ADS)

Gibson, Carl H.

2012-03-01

The 2011 Nobel Prize in Physics was awarded for the discovery of accelerating super- novae dimness, suggesting a remarkable reversal in the expansion rate of the Universe from a decrease to an increase, driven by anti-gravity forces of a mysterious dark energy material comprising 70% of the Universe mass-energy. Fluid mechanics and Herschel- Planck-Spitzer-Hubble etc. space telescope observations falsify both the accelerating ex- pansion rate and dark energy concepts. Kinematic viscosity is neglected in models of self-gravitational structure formation. Large plasma photon viscosity predicts protosu- perclustervoid fragmentation early in the plasma epoch and protogalaxies at the end. At the plasma-gas transition, the gas protogalaxies fragment into Earth-mass rogue plan- ets in highly persistent, trillion-planet clumps (proto-globular-star-cluster PGCs). PGC planets freeze to form the dark matter of galaxies and merge to form their stars, giving the hydrogen triple-point (14 K) infrared emissions observed. Dark energy is a system- atic dimming error for Supernovae Ia caused by partially evaporated planets feeding hot white dwarf stars at the Chandrasekhar carbon limit. Planet atmospheres may or may not dim light from SNe-Ia events depending on the line of sight.

Hydro-mechanical properties of the Red Salt Clay (T4) - Relevancy of the minimum stress criterion for barrier integrity

NASA Astrophysics Data System (ADS)

Minkley, W.; Popp, T.; Salzer, K.; Gruner, M.; Böttge, V.

The so-called Red Salt Clay (T4) is deposited as clay-rich clastic sediment at the base of the Aller-series forming a persistent lateral layer of up to 20 m thickness above the lower Zechstein-series. The clay layers may act as a protective shield in the hanging wall of gas storages or underground repositories in salt formations, thus resulting in a multi-barrier system. As a proof of its reliability comprehensive hydro-mechanical investigations were performed on clay samples recovered at different sites in Germany. Most important, rock tightness against various fluids was confirmed in the lab and field-scale. Remarkably, only if the fluid pressure equalises the acting minimal stress (i.e. violence of the “minimum stress criterion”) a significant increase of permeability is observed (“pathway dilatation”) but no macro-frac. However, the material properties from different locations showed a significant variability according to different burial depths. Thus the Red Salt Clay may act as natural analogue, representing the material variability of various indurated clays. In addition, the existing knowledge gained from practical mining activities can be used to evaluate extreme in situ loading conditions.

Nonuniform spatial patterns of respiratory activity within biofilms during disinfection.

PubMed Central

Huang, C T; Yu, F P; McFeters, G A; Stewart, P S

1995-01-01

Fluorescent stains in conjunction with cryoembedding and image analysis were applied to demonstrate spatial gradients in respiratory activity within bacterial biofilms during disinfection with monochloramine. Biofilms of Klebsiella pneumoniae and Pseudomonas aeruginosa grown together on stainless steel surfaces in continuous-flow annular reactors were treated with 2 mg of monochloramine per liter (influent concentration) for 2 h. Relatively little biofilm removal occurred as evidenced by total cell direct counts. Plate counts (of both species summed) indicated an average 1.3-log decrease after exposure to 2 mg of monochloramine per liter. The fluorogenic redox indicator 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and the DNA stain 4',6-diamidino-2-phenylindole (DAPI) were used to differentiate respiring and nonrespiring cells in biofilms. Epifluorescence micrographs of frozen biofilm cross sections clearly revealed gradients of respiratory activity within biofilms in response to monochloramine treatment. These gradients in specific respiratory activity were quantified by calculating the ratio of CTC and DAPI intensities measured by image analysis. Cells near the biofilm-bulk fluid interface lost respiratory activity first. After 2 h of biocide treatment, greater respiratory activity persisted deep in the biofilm than near the biofilm-bulk fluid interface. PMID:7793945

Radiation inhibits salivary gland function by promoting STIM1 cleavage by caspase-3 and loss of SOCE through a TRPM2-dependent pathway

PubMed Central

Liu, Xibao; Gong, Baijuan; de Souza, Lorena Brito; Ong, Hwei Ling; Subedi, Krishna P.; Cheng, Kwong Tai; Swaim, William; Zheng, Changyu; Mori, Yasuo; Ambudkar, Indu S.

2017-01-01

Store-operated Ca2+ entry (SOCE) is critical for salivary gland fluid secretion. We report that radiation treatment caused persistent salivary gland dysfunction by activating a TRPM2-dependent mitochondrial pathway, leading to caspase-3–mediated cleavage of stromal interaction molecule 1 (STIM1) and loss of SOCE. After irradiation, acinar cells from the submandibular glands of TRPM2+/+, but not those from TRPM2−/− mice, displayed an increase in the concentrations of mitochondrial Ca2+ and reactive oxygen species, a decrease in mitochondrial membrane potential, and activation of caspase-3, which was associated with a sustained decrease in STIM1 abundance and attenuation of SOCE. In a salivary gland cell line, silencing the mitochondrial Ca2+ uniporter or caspase-3 or treatment with inhibitors of TRPM2 or caspase-3 prevented irradiation-induced loss of STIM1 and SOCE. Expression of exogenous STIM1 in the salivary glands of irradiated mice increased SOCE and fluid secretion. We suggest that targeting the mechanisms underlying the loss of STIM1 would be a potentially useful approach for preserving salivary gland function after radiation therapy. PMID:28588080

Whole body MRI: Improved Lesion Detection and Characterization With Diffusion Weighted Techniques

PubMed Central

Attariwala, Rajpaul; Picker, Wayne

2013-01-01

Diffusion-weighted imaging (DWI) is an established functional imaging technique that interrogates the delicate balance of water movement at the cellular level. Technological advances enable this technique to be applied to whole-body MRI. Theory, b-value selection, common artifacts and target to background for optimized viewing will be reviewed for applications in the neck, chest, abdomen, and pelvis. Whole-body imaging with DWI allows novel applications of MRI to aid in evaluation of conditions such as multiple myeloma, lymphoma, and skeletal metastases, while the quantitative nature of this technique permits evaluation of response to therapy. Persisting signal at high b-values from restricted hypercellular tissue and viscous fluid also permits applications of DWI beyond oncologic imaging. DWI, when used in conjunction with routine imaging, can assist in detecting hemorrhagic degradation products, infection/abscess, and inflammation in colitis, while aiding with discrimination of free fluid and empyema, while limiting the need for intravenous contrast. DWI in conjunction with routine anatomic images provides a platform to improve lesion detection and characterization with findings rivaling other combined anatomic and functional imaging techniques, with the added benefit of no ionizing radiation. PMID:23960006

Dual transmission model of the fetal heart tone

NASA Astrophysics Data System (ADS)

Baker, Donald A.; Zuckerwar, Allan J.

2004-05-01

Detection of the fetal heart tone by auscultation is sometimes easy, other times very difficult. In the model proposed here, the level of difficulty depends upon the position of the fetus within the maternal abdomen. If the fetus lies in the classical left/right occiput anterior position (head down, back against the maternal abdominal wall), detection by a sensor or stethoscope on the maternal abdominal surface is easy. In this mode, named here the ``direct contact'' mode, the heartbeat pushes the fetus against the detecting sensor. The motion generates pressure by impact and does not involve acoustic propagation at all. If the fetus lies in a persistent occiput posterior position (spine-to-spine, fetus facing forward), detection is difficult. In this, the ``fluid propagation'' mode, sound generated by the fetal heart and propagating across the amniotic fluid produces extremely weak signals at the maternal surface, typically 30 dB lower than those of the direct contact mode. This reduction in tone level can be compensated by judicious selection of detection frequency band and by exploiting the difference between the background noise levels of the two modes. Experimental clinical results, demonstrating the tones associated with the two respective modes, will be presented.

Transfer of immunoglobulins and antibodies in the hen's egg

PubMed Central

Kramer, T. T.; Cho, H. C.

1970-01-01

The presence of immunoglobulins and antibodies were investigated in the fertile hen's egg during embryogenesis. The egg yolk, egg albumin, amniotic and allantoic fluids, chick embryo serum and intestinal contents were examined for the presence of immunoglobulin and level of antibodies. Immunoglobulin G was not detected in fresh egg albumin, but appeared in the albumin from the 4th day of embryogenesis and persisted through the 16th day. The antibody profile of egg albumin during embryogenesis attained two peaks, which were separated by a trough on the 8th day of embryogenesis. The immunoelectrophoretic pattern of albumin IgG was different from that of egg yolk IgG. The IgG of chick embryo serum was of γ2 mobility on the 12th day of incubation and shifted gradually to the full range of γ1 and γ2 mobilities on the 20th day of incubation. Egg-transmitted antibodies appeared on the 12th day of incubation and attained peak values on the 16th day of incubation. Moderate antibody levels were detected in the amniotic and allantoic fluids from the 12th to the 18th days of incubation. ImagesFIG. 1FIG. 2FIG. 4FIG. 5FIG. 7 PMID:4098593

Climate-driven flushing of pore water in peatlands

NASA Astrophysics Data System (ADS)

Siegel, D. I.; Reeve, A. S.; Glaser, P. H.; Romanowicz, E. A.

1995-04-01

NORTHERN peatlands can act as either important sources or sinks for atmospheric carbon1,2. It is therefore important to understand how carbon cycling in these regions will respond to a changing climate. Existing carbon balance models for peatlands assume that fluid flow and advective mass transport are negligible at depth3,4, and that the effects of climate change should be essentially limited to the near-surface. Here we report the response of groundwater flow and porewater chemistry in the Glacial Lake Agassiz peat-lands of northern Minnesota to the regional drought cycle. Comparison of field observations and numerical simulations indicates that climate fluctuations of short duration may temporarily reverse the vertical direction of fluid flow through the peat, although this has little effect on water chemistry5. On the other hand, periods of drought persisting for at least 3-5 years produce striking changes in the chemistry of the pore water. These longer-term changes in hydrology influence the flux of nutrients and dissolved organic matter through the deeper peat, and therefore affect directly the rates of fermentation and methanogenesis, and the export of dissolved carbon compounds from the peatland.

The rheological behavior of fracture-filling cherts: example of Barite Valley dikes, Barberton Greenstone Belt, South Africa

NASA Astrophysics Data System (ADS)

Ledevin, M.; Arndt, N.; Simionovici, A.

2014-05-01

A 100 m-thick complex of near-vertical carbonaceous chert dikes marks the transition from the Mendon to Mapepe Formations (3260 Ma) in the Barberton Greenstone Belt, South Africa. Fracturing was intense in this area, as shown by the profusion and width of the dikes (ca. 1 m on average) and by the abundance of completely shattered rocks. The dike-and-sill organization of the fracture network and the upward narrowing of some of the large veins indicate that at least part of the fluid originated at depth and migrated upward in this hydrothermal plumbing system. Abundant angular fragments of silicified country rock are suspended and uniformly distributed within the larger dikes. Jigsaw-fit structures and confined bursting textures indicate that hydraulic fracturing was at the origin of the veins. The confinement of the dike system beneath an impact spherule bed suggests that the hydrothermal circulations were triggered by the impact and located at the external margin of a large crater. From the geometry of the dikes and the petrography of the cherts, we infer that the fluid that invaded the fractures was thixotropic. On one hand, the injection of black chert into extremely fine fractures is evidence for low viscosity at the time of injection; on the other hand, the lack of closure of larger veins and the suspension of large fragments in a chert matrix provide evidence of high viscosity soon thereafter. The inference is that the viscosity of the injected fluid increased from low to high as the fluid velocity decreased. Such rheological behavior is characteristic of media composed of solid and colloidal particles suspended in a liquid. The presence of abundant clay-sized, rounded particles of silica, carbonaceous matter and clay minerals, the high proportion of siliceous matrix and the capacity of colloidal silica to form cohesive 3-D networks through gelation, account for the viscosity increase and thixotropic behavior of the fluid that filled the veins. Stirring and shearing of the siliceous mush as it was injected imparted a low viscosity by decreasing internal particle interactions; then, as the flow rate declined, the fluid became highly viscous as the inter-particulate bonds (siloxane bonds, Si-O-Si) were reconstituted. The gelation of the chert was rapid and the structure persisted at low temperature (T < 200 °C) before fractures were sealed and chert indurated.

1D Thermal-Hydraulic-Chemical (THC) Reactive transport modeling for deep geothermal systems: A case study of Groß Schönebeck reservoir, Germany

NASA Astrophysics Data System (ADS)

Driba, D. L.; De Lucia, M.; Peiffer, S.

2014-12-01

Fluid-rock interactions in geothermal reservoirs are driven by the state of disequilibrium that persists among solid and solutes due to changing temperature and pressure. During operation of enhanced geothermal systems, injection of cooled water back into the reservoir disturbs the initial thermodynamic equilibrium between the reservoir and its geothermal fluid, which may induce modifications in permeability through changes in porosity and pore space geometry, consequently bringing about several impairments to the overall system.Modeling of fluid-rock interactions induced by injection of cold brine into Groß Schönebeck geothermal reservoir system situated in the Rotliegend sandstone at 4200m depth have been done by coupling geochemical modeling Code Phreeqc with OpenGeoSys. Through batch modeling the re-evaluation of the measured hydrochemical composition of the brine has been done using Quintessa databases, the results from the calculation indicate that a mineral phases comprising of K-feldspar, hematite, Barite, Calcite and Dolomite was found to match the hypothesis of equilibrium with the formation fluid, Reducing conditions are presumed in the model (pe = -3.5) in order to match the amount of observed dissolved Fe and thus considered as initial state for the reactive transport modeling. based on a measured composition of formation fluids and the predominant mineralogical assemblage of the host rock, a preliminary 1D Reactive transport modeling (RTM) was run with total time set to 30 years; results obtained for the initial simulation revealed that during this period, no significant change is evident for K-feldspar. Furthermore, the precipitation of calcite along the flow path in the brine results in a drop of pH from 6.2 to a value of 5.2 noticed over the simulated period. The circulation of cooled fluid in the reservoir is predicted to affect the temperature of the reservoir within the first 100 -150m from the injection well. Examination of porosity change in this simulation reveals that, porosity and permeability near the wellbore are enhanced after injection. This is chiefly due to the dissolution of calcite near the injection well and less extent by dolomite The porosity is improved by more than 14% at the injection well, but then decreases away from the well.

Saline versus balanced crystalloids for intravenous fluid therapy in the emergency department: study protocol for a cluster-randomized, multiple-crossover trial.

PubMed

Self, Wesley H; Semler, Matthew W; Wanderer, Jonathan P; Ehrenfeld, Jesse M; Byrne, Daniel W; Wang, Li; Atchison, Leanne; Felbinger, Matthew; Jones, Ian D; Russ, Stephan; Shaw, Andrew D; Bernard, Gordon R; Rice, Todd W

2017-04-13

Prior studies in critically ill patients suggest the supra-physiologic chloride concentration of 0.9% ("normal") saline may be associated with higher risk of renal failure and death compared to physiologically balanced crystalloids. However, the comparative effects of 0.9% saline and balanced fluids are largely unexamined among patients outside the intensive care unit, who represent the vast majority of patients treated with intravenous fluids. This study, entitled Saline Against Lactated Ringer's or Plasma-Lyte in the Emergency Department (SALT-ED), is a pragmatic, cluster, multiple-crossover trial at a single institution evaluating clinical outcomes of adults treated with 0.9% saline versus balanced crystalloids for intravenous fluid resuscitation in the emergency department. All adults treated in the study emergency department receiving at least 500 mL of isotonic crystalloid solution during usual clinical care and subsequently hospitalized outside the intensive care unit are included. Treatment allocation of 0.9% saline versus balanced crystalloids is assigned by calendar month, with study patients treated during the same month assigned to the same fluid type. The first month (January 2016) was randomly assigned to balanced crystalloids, with each subsequent month alternating between 0.9% saline and balanced crystalloids. For balanced crystalloid treatment, clinicians can choose either Lactated Ringer's or Plasma-Lyte A©. The study period is set at 16 months, which will result in an anticipated estimated sample size of 15,000 patients. The primary outcome is hospital-free days to day 28, defined as the number of days alive and out of the hospital from the index emergency department visit until 28 days later. Major secondary outcomes include proportion of patients who develop acute kidney injury by creatinine measurements; major adverse kidney events by hospital discharge or day 30 (MAKE30), which is a composite outcome of death, new renal replacement therapy, and persistent creatinine elevation >200% of baseline; and in-hospital mortality. This ongoing pragmatic trial will provide the most comprehensive evaluation to date of clinical outcomes associated with 0.9% saline compared to physiologically balanced fluids in patients outside the intensive care unit. ClinicalTrials.gov, NCT02614040 . Registered on 18 November 2015.

Fluid particles only separate exponentially in the dissipation range of turbulence after extremely long times

NASA Astrophysics Data System (ADS)

Dhariwal, Rohit; Bragg, Andrew D.

2018-03-01

In this paper, we consider how the statistical moments of the separation between two fluid particles grow with time when their separation lies in the dissipation range of turbulence. In this range, the fluid velocity field varies smoothly and the relative velocity of two fluid particles depends linearly upon their separation. While this may suggest that the rate at which fluid particles separate is exponential in time, this is not guaranteed because the strain rate governing their separation is a strongly fluctuating quantity in turbulence. Indeed, Afik and Steinberg [Nat. Commun. 8, 468 (2017), 10.1038/s41467-017-00389-8] argue that there is no convincing evidence that the moments of the separation between fluid particles grow exponentially with time in the dissipation range of turbulence. Motivated by this, we use direct numerical simulations (DNS) to compute the moments of particle separation over very long periods of time in a statistically stationary, isotropic turbulent flow to see if we ever observe evidence for exponential separation. Our results show that if the initial separation between the particles is infinitesimal, the moments of the particle separation first grow as power laws in time, but we then observe convincing evidence that at sufficiently long times the moments do grow exponentially. However, this exponential growth is only observed after extremely long times ≳200 τη , where τη is the Kolmogorov time scale. This is due to fluctuations in the strain rate about its mean value measured along the particle trajectories, the effect of which on the moments of the particle separation persists for very long times. We also consider the backward-in-time (BIT) moments of the article separation, and observe that they too grow exponentially in the long-time regime. However, a dramatic consequence of the exponential separation is that at long times the difference between the rate of the particle separation forward in time (FIT) and BIT grows exponentially in time, leading to incredibly strong irreversibility in the dispersion. This is in striking contrast to the irreversibility of their relative dispersion in the inertial range, where the difference between FIT and BIT is constant in time according to Richardson's phenomenology.

The role of fluid mobility in the development of shale weathering profiles: Direct observations from a vadose zone monitoring system

NASA Astrophysics Data System (ADS)

Druhan, J. L.; Wang, J.; Cargill, S.; Murphy, C.; Tune, A. K.; Dietrich, W. E.; Rempe, D.

2017-12-01

Extensive effort has focused on resolving the contribution of weathering reactions to the transfer of mass over scales ranging from individual hillslope weathering profiles, across local watersheds, to continental drainage networks. A persistent limitation in quantifying these fluxes is the variability in fluid flowpaths through the subsurface, which may alter the extent of chemical weathering relative to that expected from idealized homogenous conditions. In the past decade, the consequence of fluid travel time on solute flux has been recognized as a key complexity in the interpretation of solute concentrations, particularly in upland watersheds characterized by fracture flowpaths, as is typical of shale-dominated landscapes. Though recent studies have suggested a variety of models for solute generation in such dual (matrix and fracture flow) domain systems, a central impediment to advancing prediction is the lack of direct observations. Here, we report solute chemistry as a function of depth across an 18 m thick vadose zone of weathered argillite (shale) in the Eel River Critical Zone Observatory (ERCZO) using novel sub-horizontal distributed samplers (Vadose Zone Monitoring System). We contrast a year of major and trace ion chemistry obtained from water samples collected approximately biweekly using two complementary sampling systems, one applying active pressure to extract matrix-bound pore fluid, and the other using a passive collection method to extract freely draining water. Precipitation falling during the winter rainy season passes through this vadose zone, causing increased rock moisture that is subsequently depleted by transpiring trees. Solute concentrations reflect these seasonal changes, and, surprisingly, normalized ion ratios span the full range of values reported for the world's largest rivers. Notably, for some major cations, freely draining water is consistently less concentrated than matrix-bound water, and the composition of vadose zone water is consistently more variable than the underlying groundwater. Dual domain 1D reactive transport simulations demonstrate that even a simplified scoping model for solute concentrations across fractured shale systems requires a non-uniform fluid travel time to reasonably reproduce observations.

A Huge Morel-Lavallée Lesion Treated Using a Quilting Suture Method: A Case Report and Review of the Literature.

PubMed

Seo, Bommie F; Kang, In Sook; Jeong, Yeon Jin; Moon, Suk Ho

2014-06-01

The Morel-Lavallée lesion is a collection of serous fluid that develops after closed degloving injuries and after surgical procedures particularly in the pelvis and abdomen. It is a persistent seroma and is usually resistant to conservative methods of treatment such as percutaneous drainage and compression. Various methods of curative treatment have been reported in the literature, such as application of fibrin sealant, doxycycline, or alcohol sclerodhesis. We present a case of a huge recurrent Morel-Lavallée lesion in the lower back and buttock region that was treated with quilting sutures, fibrin sealant, and compression, with a review of the literature. © The Author(s) 2014.

Recurring ventriculitis due to Citrobacter diversus: clinical and bacteriologic analysis.

PubMed

Eppes, S C; Woods, C R; Mayer, A S; Klein, J D

1993-09-01

Neonatal meningitis due to Citrobacter diversus is usually accompanied by the development of brain abscesses and tends to have high rates of morbidity and mortality. We report a case of a newborn with C. diversus meningitis and brain abscesses who relapsed after initial antibiotic therapy and from whom C. diversus was recovered from cerebrospinal fluid 4 years later during a neurosurgical procedure. Genetic differences in the early and late isolates were discovered, and explanations for this phenomenon are suggested. Possible mechanisms for prolonged persistence in the central nervous system are explored. This unusual case and the analysis of the organisms illustrate the unique features of C. diversus as a pathogen and underscore the need for developing optimal therapeutic strategies.

[Treatment of acne with consequences -- pseudotumor cerebri due to hypervitaminosis A].

PubMed

Meyer-Heim, A; Landau, K; Boltshauser, E

2002-01-09

Pseudotumor cerebri (PTC) is an entity characterized by elevated intracranial pressure of probably multifactoral origin, but most cases remain idiopathic. We report a 15-year-old girl with PTC due to prolonged consumption of Arovit (Vitamin A) for treatment of acne. The diagnosis was established by measuring raised cerebrospinal fluid pressure after an intracranial mass lesion and dural venous sinsus thrombosis were excluded. The increased level of vitamin A confirmed the diagnosis of hypervitaminosis A as the causative pathogen. The patient was treated with lumbar punctures and acetazolamide (Diamox). PTC due to hypervitaminosis A is a serious complication, which can cause permanent visual impairment. Patients treated with retinoids require proper surveillance. The elevated serum level of retinoids after withdrawal may persist for weeks.

PCB residues in the adipose tissue of the population of Barcelona (Spain)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez-Catalan, J.; Sabroso, M.; To-Figueras, J.

1991-10-01

Polychlorinated biphenyls (PCBs) are a class of aryl halides widely distributed in the environment. Although production has virtually ceased, and most industrial applications (capacitors, transformers, hydraulic fluids, lubricants, etc) are severely restricted, they are one of the most ubiquitous and persistent environmental pollutants. Several toxic effects caused by PCBs have been described including: liver enlargement, hepatomegalocytosis, acne, lymphoid atrophy, immunosuppression, tumor promotion, porphyria. This work continues the authors' previous reports about organochlorine residues in human tissues of some Spanish populations, that showed high levels of some residues, specially of hexachlorobenzene (HCB). PCBs pattern and concentration in the adipose tissue ofmore » the inhabitants of an urban and industrial area (Barcelona) were determined.« less

[Tuberculous meningitis with atypical presentation in a patient with human immunodeficiency virus infection].

PubMed

López, M T; Lluch, M; Fernández-Solá, J; Coca, A; Urbano-Márquez, A

1992-04-11

A 32 years old male patient is described with infection by the human immunodeficiency virus (HIV) on stage IV C1 and with positive Ag p24 who developed tuberculous meningitis of atypical presentation. A persistent liquoral neutrophilia and low adenosindeaminase values were observed in cerebrospinal fluid of purulent appearance. The patient responded badly to tuberculostatic treatment and died. In the antibiogram carried out resistance to Mycobacterium tuberculosis was observed to rifampicine and isoniazide, two of the five drugs the patient had received. The peculiarities of the clinical form of presentation similar to purulent bacterian meningitis are discussed, and the possible influence of HIV infection and the antibiotic multiresistance observed in the bad evolution of the tuberculous meningitis which the patient developed.

Central venous O2 saturation and venous-to-arterial CO2 difference as complementary tools for goal-directed therapy during high-risk surgery

PubMed Central

2010-01-01

Introduction Central venous oxygen saturation (ScvO2) is a useful therapeutic target in septic shock and high-risk surgery. We tested the hypothesis that central venous-to-arterial carbon dioxide difference (P(cv-a)CO2), a global index of tissue perfusion, could be used as a complementary tool to ScvO2 for goal-directed fluid therapy (GDT) to identify persistent low flow after optimization of preload has been achieved by fluid loading during high-risk surgery. Methods This is a secondary analysis of results obtained in a study involving 70 adult patients (ASA I to III), undergoing major abdominal surgery, and treated with an individualized goal-directed fluid replacement therapy. All patients were managed to maintain a respiratory variation in peak aortic flow velocity below 13%. Cardiac index (CI), oxygen delivery index (DO2i), ScvO2, P(cv-a)CO2 and postoperative complications were recorded blindly for all patients. Results A total of 34% of patients developed postoperative complications. At baseline, there was no difference in demographic or haemodynamic variables between patients who developed complications and those who did not. In patients with complications, during surgery, both mean ScvO2 (78 ± 4 versus 81 ± 4%, P = 0.017) and minimal ScvO2 (minScvO2) (67 ± 6 versus 72 ± 6%, P = 0.0017) were lower than in patients without complications, despite perfusion of similar volumes of fluids and comparable CI and DO2i values. The optimal ScvO2 cut-off value was 70.6% and minScvO2 < 70% was independently associated with the development of postoperative complications (OR = 4.2 (95% CI: 1.1 to 14.4), P = 0.025). P(cv-a)CO2 was larger in patients with complications (7.8 ± 2 versus 5.6 ± 2 mmHg, P < 10-6). In patients with complications and ScvO2 ≥71%, P(cv-a)CO2 was also significantly larger (7.7 ± 2 versus 5.5 ± 2 mmHg, P < 10-6) than in patients without complications. The area under the receiver operating characteristic (ROC) curve was 0.785 (95% CI: 0.74 to 0.83) for discrimination of patients with ScvO2 ≥71% who did and did not develop complications, with 5 mmHg as the most predictive threshold value. Conclusions ScvO2 reflects important changes in O2 delivery in relation to O2 needs during the perioperative period. A P(cv-a)CO2 < 5 mmHg might serve as a complementary target to ScvO2 during GDT to identify persistent inadequacy of the circulatory response in face of metabolic requirements when an ScvO2 ≥71% is achieved. Trial registration Clinicaltrials.gov Identifier: NCT00852449. PMID:21034476

Plates and Mantle Convection: A Far-From Equilibrium Self-Organized System

NASA Astrophysics Data System (ADS)

King, S. D.; Lowman, J. P.; Gable, C. W.

2001-12-01

A common observation of plate tectonics is that plate velocities change over short time scales. Some have speculated that these reorganization events are triggered by evolving plate boundaries. This work presents an alternative mechanism, due to the interaction of mobil plates and internally heated convection. We present numerical models of 3D Cartesian convection in an internally-heated fluid with mobile plates that exhibit rapid changes in plate motion. A persistent feature of these calculations is that plate motion is relatively uniform punctuated by rapid reorganization events where plate speed and direction change over a short time period. The rapid changes in plate motion result solely from the interaction of internally-heated convection and the mobile plates. Without plates, the convective planform of an internally-heated fluid evolves into a pattern with a larger number of small cells. When plates are included, the fluid is dominated by plate-scale structures; however, isolated regions develop where heat builds up. These isolated regions are near the location of mature slabs where the plates are older and thicker. As the system evolves, the temperature (and buoyancy) in these isolated regions increases, they become unstable and, as they rise, the net force on the plate is no longer dominated by `slab pull' from the mature slab. The plate reorganization allows the system to transfer heat from the short-wavelength, internal-heating scale, to the longer-wavelength, plate-cooling scale. As we will demonstrate, the interaction between plate motions and the mantle is sufficiently dynamic that evolving plate boundaries are not necessary to achieve rapid changes in plate motion.

Lagrangian coherent structures in low Reynolds number swimming.

PubMed

Wilson, Megan M; Peng, Jifeng; Dabiri, John O; Eldredge, Jeff D

2009-05-20

This work explores the utility of the finite-time Lyapunov exponent (FTLE) field for revealing flow structures in low Reynolds number biological locomotion. Previous studies of high Reynolds number unsteady flows have demonstrated that ridges of the FTLE field coincide with transport barriers within the flow, which are not shown by a more classical quantity such as vorticity. In low Reynolds number locomotion (O(1)-O(100)), in which viscous diffusion rapidly smears the vorticity in the wake, the FTLE field has the potential to add new insight to locomotion mechanics. The target of study is an articulated two-dimensional model for jellyfish-like locomotion, with swimming Reynolds number of order 1. The self-propulsion of the model is numerically simulated with a viscous vortex particle method, using kinematics adapted from previous experimental measurements on a live medusan swimmer. The roles of the ridges of the computed forward- and backward-time FTLE fields are clarified by tracking clusters of particles both backward and forward in time. It is shown that a series of ridges in front of the jellyfish in the forward-time FTLE field transport slender fingers of fluid toward the lip of the bell orifice, which are pulled once per contraction cycle into the wake of the jellyfish, where the fluid remains partitioned. A strong ridge in the backward-time FTLE field reveals a persistent barrier between fluid inside and outside the subumbrellar cavity. The system is also analyzed in a body-fixed frame subject to a steady free stream, and the FTLE field is used to highlight differences in these frames of reference.

The effects of chronic binge alcohol on the genital microenvironment of simian immunodeficiency virus-infected female rhesus macaques.

PubMed

Loganantharaj, Nisha; Nichols, Whitney A; Bagby, Gregory J; Volaufova, Julia; Dufour, Jason; Martin, David H; Nelson, Steve; Amedee, Angela M

2014-08-01

Alcohol abuse is a widespread problem among those at risk for and living with HIV and can impact transmission and disease progression. In this study we sought to use the simian immunodeficiency virus (SIV)-macaque model to evaluate the immunological and virological changes in the genital microenvironment of females exposed to chronic alcohol. Female rhesus macaques were treated with alcohol (n=6) or isocaloric sucrose (n=6) for 3 months and then inoculated with SIVmac251. To assess the effects of chronic alcohol on SIV disease and the genital microenvironment, we quantified plasma and genital SIV levels, measured inflammatory cells in genital fluids, and characterized microbial flora by gram stains over 10 weeks post-SIV infection. Following 3 months of alcohol/sucrose treatment, significant differences were observed in the vaginal microenvironment of alcohol-treated animals as compared to controls. Microbial flora of alcohol-treated animals had decreased levels of lactobacillus morphotypes and increased levels of gram-positive cocci relative to sucrose controls. Alcohol-treated animals were also more likely to have white blood cells in vaginal fluids prior to SIV inoculation, which persisted through viral set point. Similar levels of cell-free SIV were observed in plasma and vaginal fluids of both groups, but alcohol-treated animals had a higher incidence and levels of cell-associated SIV shed in vaginal secretions. Chronic alcohol treatment negatively impacts the genital microenvironment prior to and over the course of SIV infection and may increase the risk of genital virus shedding and transmission.

Cold Seep Epifaunal Communities on the Hikurangi Margin, New Zealand: Composition, Succession, and Vulnerability to Human Activities

PubMed Central

Bowden, David A.; Rowden, Ashley A.; Thurber, Andrew R.; Baco, Amy R.; Levin, Lisa A.; Smith, Craig R.

2013-01-01

Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to information about the probable life-history characteristics of the principal fauna to develop a hypothetical succession sequence for the Hikurangi seep communities, from the onset of fluid flux to senescence. New Zealand seep communities exhibit taxa characteristic of seeps in other regions, including predominance of large siboglinid tubeworms, vesicomyid clams, and bathymodiolin mussels. Some aspects appear to be novel; however, particularly the association of dense populations of ampharetid polychaetes with high-sulphide, high-methane flux, soft-sediment microhabitats. The common occurrence of these ampharetids suggests they play a role in conditioning sulphide-rich sediments at the sediment-water interface, thus facilitating settlement of clam and tubeworm taxa which dominate space during later successional stages. The seep sites are subject to disturbance from bottom trawling at present and potentially from gas hydrate extraction in future. The likely life-history characteristics of the dominant megafauna suggest that while ampharetids, clams, and mussels exploit ephemeral resources through rapid growth and reproduction, lamellibrachid tubeworm populations may persist potentially for centuries. The potential consequences of gas hydrate extraction cannot be fully assessed until extraction methods and target localities are defined but any long-term modification of fluid flow to seep sites would have consequences for all chemoautotrophic fauna. PMID:24204691

Release of beryllium from mineral ores in artificial lung and skin surface fluids.

PubMed

Duling, Matthew G; Stefaniak, Aleksandr B; Lawrence, Robert B; Chipera, Steve J; Virji, M Abbas

2012-06-01

Exposure to some manufactured beryllium compounds via skin contact or inhalation can cause sensitization. A portion of sensitized persons who inhale beryllium may develop chronic beryllium disease (CBD). Little is understood about exposures to naturally occurring beryllium minerals. The purpose of this study was to assess the bioaccessibility of beryllium from bertrandite ore. Dissolution of bertrandite from two mine pits (Monitor and Blue Chalk) was evaluated for both the dermal and inhalation exposure pathways by determining bioaccessibility in artificial sweat (pH 5.3 and pH 6.5), airway lining fluid (SUF, pH 7.3), and alveolar macrophage phagolysosomal fluid (PSF, pH 4.5). Significantly more beryllium was released from Monitor pit ore than Blue Chalk pit ore in artificial sweat buffered to pH 5.3 (0.88 ± 0.01% vs. 0.36 ± 0.00%) and pH 6.5 (0.09 ± 0.00% vs. 0.03 ± 0.01%). Rates of beryllium released from the ores in artificial sweat were faster than previously measured for manufactured forms of beryllium (e.g., beryllium oxide), known to induce sensitization in mice. In SUF, levels of beryllium were below the analytical limit of detection. In PSF, beryllium dissolution was biphasic (initial rapid diffusion followed by latter slower surface reactions). During the latter phase, dissolution half-times were 1,400 to 2,000 days, and rate constants were ~7 × 10(-10) g/(cm(2)·day), indicating that bertrandite is persistent in the lung. These data indicate that it is prudent to control skin and inhalation exposures to bertrandite dusts.

Cold seep epifaunal communities on the Hikurangi margin, New Zealand: composition, succession, and vulnerability to human activities.

PubMed

Bowden, David A; Rowden, Ashley A; Thurber, Andrew R; Baco, Amy R; Levin, Lisa A; Smith, Craig R

2013-01-01

Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to information about the probable life-history characteristics of the principal fauna to develop a hypothetical succession sequence for the Hikurangi seep communities, from the onset of fluid flux to senescence. New Zealand seep communities exhibit taxa characteristic of seeps in other regions, including predominance of large siboglinid tubeworms, vesicomyid clams, and bathymodiolin mussels. Some aspects appear to be novel; however, particularly the association of dense populations of ampharetid polychaetes with high-sulphide, high-methane flux, soft-sediment microhabitats. The common occurrence of these ampharetids suggests they play a role in conditioning sulphide-rich sediments at the sediment-water interface, thus facilitating settlement of clam and tubeworm taxa which dominate space during later successional stages. The seep sites are subject to disturbance from bottom trawling at present and potentially from gas hydrate extraction in future. The likely life-history characteristics of the dominant megafauna suggest that while ampharetids, clams, and mussels exploit ephemeral resources through rapid growth and reproduction, lamellibrachid tubeworm populations may persist potentially for centuries. The potential consequences of gas hydrate extraction cannot be fully assessed until extraction methods and target localities are defined but any long-term modification of fluid flow to seep sites would have consequences for all chemoautotrophic fauna.

Designing an information search interface for younger and older adults.

PubMed

Pak, Richard; Price, Margaux M

2008-08-01

The present study examined Web-based information retrieval as a function of age for two information organization schemes: hierarchical organization and one organized around tags or keywords. Older adults' performance in information retrieval tasks has traditionally been lower compared with younger adults'. The current study examined the degree to which information organization moderated age-related performance differences on an information retrieval task. The theory of fluid and crystallized intelligence may provide insight into different kinds of information architectures that may reduce age-related differences in computer-based information retrieval performance. Fifty younger (18-23 years of age) and 50 older (55-76 years of age) participants browsed a Web site for answers to specific questions. Half of the participants browsed the hierarchically organized system (taxonomy), which maintained a one-to-one relationship between menu link and page, whereas the other half browsed the tag-based interface, with a many-to-one relationship between menu and page. This difference was expected to interact with age-related differences in fluid and crystallized intelligence. Age-related differences in information retrieval performance persisted; however, a tag-based retrieval interface reduced age-related differences, as compared with a taxonomical interface. Cognitive aging theory can lead to interface interventions that reduce age-related differences in performance with technology. In an information retrieval paradigm, older adults may be able to leverage their increased crystallized intelligence to offset fluid intelligence declines in a computer-based information search task. More research is necessary, but the results suggest that information retrieval interfaces organized around keywords may reduce age-related differences in performance.

Dynamics of African swine fever virus shedding and excretion in domestic pigs infected by intramuscular inoculation and contact transmission.

PubMed

Guinat, Claire; Reis, Ana Luisa; Netherton, Christopher L; Goatley, Lynnette; Pfeiffer, Dirk U; Dixon, Linda

2014-09-26

African swine fever virus (ASFV) is a highly virulent swine pathogen that has spread across Eastern Europe since 2007 and for which there is no effective vaccine or treatment available. The dynamics of shedding and excretion is not well known for this currently circulating ASFV strain. Therefore, susceptible pigs were exposed to pigs intramuscularly infected with the Georgia 2007/1 ASFV strain to measure those dynamics through within- and between-pen transmission scenarios. Blood, oral, nasal and rectal fluid samples were tested for the presence of ASFV by virus titration (VT) and quantitative real-time polymerase chain reaction (qPCR). Serum was tested for the presence of ASFV-specific antibodies. Both intramuscular inoculation and contact transmission resulted in development of acute disease in all pigs although the experiments indicated that the pathogenesis of the disease might be different, depending on the route of infection. Infectious ASFV was first isolated in blood among the inoculated pigs by day 3, and then chronologically among the direct and indirect contact pigs, by day 10 and 13, respectively. Close to the onset of clinical signs, higher ASFV titres were found in blood compared with nasal and rectal fluid samples among all pigs. No infectious ASFV was isolated in oral fluid samples although ASFV genome copies were detected. Only one animal developed antibodies starting after 12 days post-inoculation. The results provide quantitative data on shedding and excretion of the Georgia 2007/1 ASFV strain among domestic pigs and suggest a limited potential of this isolate to cause persistent infection.

HIGH-DOSE HIGH-FREQUENCY AFLIBERCEPT FOR RECALCITRANT NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

PubMed

You, Qi Sheng; Gaber, Raouf; Meshi, Amit; Ramkumar, Hema L; Alam, Mostafa; Muftuoglu, Ilkay Kilic; Freeman, William R

2018-06-01

To determine the efficacy of monthly (0.1 mL/4 mg) aflibercept for refractory neovascular age-related macular degeneration (wet age-related macular degeneration). This was a retrospective interventional case series in which patients with wet age-related macular degeneration were treated with stepwise dose escalation. Nonvitrectomized patients resistant to monthly (Q4W) ranibizumab/bevacizumab were switched to 2 mg aflibercept every 8 weeks. With resistance, they were escalated to Q4W 2 mg aflibercept, then Q4W 4 mg (high dose high frequency, 4Q4W) aflibercept. Resistance was defined as ≥2 recurrences after being dry following ≥3 injections or persistent exudation on treatment of ≥5 injections. Thirty-three eyes of 28 patients were treated with 4Q4W aflibercept and followed for a mean of 16 months. A dry retina (no intraretinal or subretinal fluid) was achieved after initiating 4Q4W aflibercept treatment at a mean of 3.8 months. Central foveal thickness, maximum foveal thickness, intraretinal fluid, subretinal fluid, and retinal pigment detachment height decreased significantly at 1 month after initiating the 4Q4W aflibercept, and the morphologic therapeutic effect was sustained until the last visit. Forty-five percent of eyes had one or more lines of vision improvement. New geographic atrophy developed in 9% of eyes during follow-up. No ocular or systemic adverse events occurred after initiating 4Q4W aflibercept. Intravitreal high-dose high-frequency aflibercept is an effective treatment for patients with refractory wet age-related macular degeneration.

The effects of physical exercise and smoking habits on the expression of SPLUNC1 in nasal lavage fluids from allergic rhinitis subjects.

PubMed

Irander, K; Borres, M P; Ghafouri, B

2014-04-01

Palate lung nasal epithelial clone (PLUNC) is a family of proteins, which are proposed to participate in the innate immune defense against infections in the upper aero-digestive tract. The aim of this study was to investigate the expression of SPLUNC1 in allergic rhinitis subjects with considerations taken to the mucosal function and smoking habits. The participants, recruited from a cohort followed from infancy, were re-examined at the age of 18 years regarding allergy development. Based on medical histories and skin prick tests the participants were classified into groups with persistent allergic rhinitis (n=18), intermittent allergic rhinitis (n = 8) and healthy controls (n = 13). Seven subjects (3, 2 and 2 in each group, respectively) reported smoking habits. The SPLUNC1 levels in nasal lavage fluids were analyzed by Western blot. Changes in the volume of the proper nasal cavity before and after physical exercise (Vol2(increase)) were analyzed by acoustic rhinometry. Compared to the control group the SPLUNC1 level was significantly lower in the persistent allergy group (3.8 ± 3.4 OD vs. 1.3 ± 1.5 OD; p = 0.02), but not in the intermittent allergy group without current exposure to allergens (3.6 ± 4.7 OD). No differences were found in Vol2(increase) between any of the allergy groups and controls. In smokers Vol2(increase) was significantly reduced (p < 0.01) and the SPLUNC1 levels were lower compared to non-smokers. A significant correlation was found between SPLUNC1 and Vol2(increase) (p < 0.01; r = 0.53) in non-smokers. Current allergen exposure has an impact on SPLUNC1 expression in nasal lavage fluid, why allergy ought to be considered in study populations where analyses of SPLUNC1 levels are included in the reports. The normal nasal decongestion after exercise was not affected by allergy in contrast to smoking habits. The correlation between SPLUNC1 levels and Vol2(increase) in non-smokers may indicate involvement of SPLUNC1in the regulation of the normal function of the nasal mucosa. Complementary studies are needed to confirm the smoke-related reduction of SPLUNC1 expression and to analyze the possible participation of SPLUNC1 in the nasal mucosa regulation. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Neuroactive steroid levels are modified in cerebrospinal fluid and plasma of post-finasteride patients showing persistent sexual side effects and anxious/depressive symptomatology.

PubMed

Melcangi, Roberto Cosimo; Caruso, Donatella; Abbiati, Federico; Giatti, Silvia; Calabrese, Donato; Piazza, Fabrizio; Cavaletti, Guido

2013-10-01

Observations performed in a subset of subjects treated with finasteride (an inhibitor of the enzyme 5α-reductase) for male pattern hair loss seem to indicate that sexual dysfunction as well as anxious/depressive symptomatology may occur at the end of the treatment and continue after discontinuation. A possible hypothesis to explain depression symptoms after finasteride treatment might be impairment in the levels of neuroactive steroids. Therefore, neuroactive steroid levels were evaluated in paired plasma and cerebrospinal fluid samples obtained from male patients who received finasteride for the treatment of androgenic alopecia and who, after drug discontinuation, still show long-term sexual side effects as well as anxious/depressive symptomatology. The levels of neuroactive steroids were evaluated by liquid chromatography-tandem mass spectrometry in three postfinasteride patients and compared to those of five healthy controls. Neuroactive steroid levels in plasma and cerebrospinal fluid of postfinasteride patients and healthy controls. At the examination, the three postfinasteride patients reported muscular stiffness, cramps, tremors, and chronic fatigue in the absence of clinical evidence of any muscular disorder or strength reduction. Severity and frequency of the anxious/depressive symptoms were quite variable; overall, all the subjects had a fairly complex and constant neuropsychiatric pattern. Assessment of neuroactive steroid levels in patients showed some interindividual differences. However, the most important finding was the comparison of their neuroactive steroid levels with those of healthy controls. Indeed, decreased levels of tetrahydroprogesterone, isopregnanolone and dihydrotestosterone and increased levels of testosterone and 17β-estradiol were reported in cerebrospinal fluid of postfinasteride patients. Moreover, decreased levels of dihydroprogesterone and increased levels of 5α-androstane-3α,17β-diol and 17β-estradiol were observed in plasma. The present observations confirm that an impairment of neuroactive steroid levels, associated with depression symptoms, is still present in androgenic alopecia patients treated with finasteride despite the discontinuation of the treatment. © 2013 International Society for Sexual Medicine.

Strain localization in usnaturated soils with large deformation

NASA Astrophysics Data System (ADS)

Song, X.; Borja, R. I.

2014-12-01

Strain localization is a ubiquitous feature of granular materials undergoing nonhomogeneous deformation. In unsaturated porous media, how the localized deformation band is formed depends crucially on the degree of saturation, since fluid in the pores of a solid imposes a volume constraint on the deformation of the solid. When fluid flow is involved, the inception of the localized deformation band also depends on the heterogeneity of a material, which is quantified in terms of the spatial variation of density, the degree of saturation, and matric suction. We present a mathematical framework for coupled solid-deformation/fluid-diffusion in unsaturated porous media that takes into account material and geometric nonlinearities [1, 2]. The framework relies on the continuum principle of thermodynamics to identify an effective, or constitutive, stress for the solid matrix, and a water retention law that highlights the interdependence of degree of saturation, suction, and porosity of the material. We discuss the role of heterogeneity, quantified either deterministically or stochastically, on the development of a persistent shear band. We derive bifurcation conditions [3] governing the initiation of such a shear band. This research is inspired by current testing techniques that allow nondestructive and non-invasive measurement of density and the degree of saturation through high-resolution imaging [4]. The numerical simulations under plane strain condition demonstrate that the bifurcation not only manifests itself on the loading response curve and but also in the space of the degree of saturation, specific volume and suction stress. References[1] Song X, Borja RI, Mathematical framework for unsaturated flow in the finite deformation range. Int. J. Numer. Meth. Engng 2014; 97: 658-686. [2] Song X, Borja RI, Finite deformation and fluid flow in unsaturated soils with random heterogeneity. Vadose Zone Journal 2014; doi:10.2136/vzj2013.07.0131. [3] Song X, Borja RI, Instability and bifurcation in partially saturated porous media. 2014. to be submitted. [4] Song X, Strain localization in unsaturated porous media. 2014. Ph.D. Dissertation, Stanford University, California.

Deformation and the timing of gas generation and migration in the eastern Brooks Range foothills, Arctic National Wildlife Refuge, Alaska

USGS Publications Warehouse

Parris, T.M.; Burruss, R.C.; O'Sullivan, P. B.

2003-01-01

Along the southeast border of the 1002 Assessment Area in the Arctic National Wildlife Refuge, Alaska, an explicit link between gas generation and deformation in the Brooks Range fold and thrust belt is provided through petrographic, fluid inclusion, and stable isotope analyses of fracture cements integrated with zircon fission-track data. Predominantly quartz-cemented fractures, collected from thrusted Triassic and Jurassic rocks, contain crack-seal textures, healed microcracks, and curved crystals and fluid inclusion populations, which suggest that cement growth occurred before, during, and after deformation. Fluid inclusion homogenization temperatures (175-250??C) and temperature trends in fracture samples suggest that cements grew at 7-10 km depth during the transition from burial to uplift and during early uplift. CH4-rich (dry gas) inclusions in the Shublik Formation and Kingak Shale are consistent with inclusion entrapment at high thermal maturity for these source rocks. Pressure modeling of these CH4-rich inclusions suggests that pore fluids were overpressured during fracture cementation. Zircon fission-track data in the area record postdeposition denudation associated with early Brooks Range deformation at 64 ?? 3 Ma. With a closure temperature of 225-240??C, the zircon fission-track data overlap homogenization temperatures of coeval aqueous inclusions and inclusions containing dry gas in Kingak and Shublik fracture cements. This critical time-temperature relationship suggests that fracture cementation occurred during early Brooks Range deformation. Dry gas inclusions suggest that Shublik and Kingak source rocks had exceeded peak oil and gas generation temperatures at the time structural traps formed during early Brooks Range deformation. The timing of hydrocarbon generation with respect to deformation therefore represents an important exploration risk for gas exploration in this part of the Brooks Range fold and thrust belt. The persistence of gas high at thermal maturity levels suggests, however, that significant volumes of gas may have been generated.

Generalized derivation of the added-mass and circulatory forces for viscous flows

NASA Astrophysics Data System (ADS)

Limacher, Eric; Morton, Chris; Wood, David

2018-01-01

The concept of added mass arises from potential flow analysis and is associated with the acceleration of a body in an inviscid irrotational fluid. When shed vorticity is modeled as vortex singularities embedded in this irrotational flow, the associated force can be superimposed onto the added-mass force due to the linearity of the governing Laplace equation. This decomposition of force into added-mass and circulatory components remains common in modern aerodynamic models, but its applicability to viscous separated flows remains unclear. The present work addresses this knowledge gap by presenting a generalized derivation of the added-mass and circulatory force decomposition which is valid for a body of arbitrary shape in an unbounded, incompressible fluid domain, in both two and three dimensions, undergoing arbitrary motions amid continuous distributions of vorticity. From the general expression, the classical added-mass force is rederived for well-known canonical cases and is seen to be additive to the circulatory force for any flow. The formulation is shown to be equivalent to existing theoretical work under the specific conditions and assumptions of previous studies. It is also validated using a numerical simulation of a pitching plate in a steady freestream flow, conducted by Wang and Eldredge [Theor. Comput. Fluid Dyn. 27, 577 (2013), 10.1007/s00162-012-0279-5]. In response to persistent confusion in the literature, a discussion of the most appropriate physical interpretation of added mass is included, informed by inspection of the derived equations. The added-mass force is seen to account for the dynamic effect of near-body vorticity and is not (as is commonly claimed) associated with the acceleration of near-body fluid which "must" somehow move with the body. Various other consequences of the derivation are discussed, including a concept which has been labeled the conservation of image-vorticity impulse.

Maglev Facility for Simulating Variable Gravity

NASA Technical Reports Server (NTRS)

Liu, Yuanming; Strayer, Donald M.; Israelsson, Ulf E.

2010-01-01

An improved magnetic levitation apparatus ("Maglev Facility") has been built for use in experiments in which there are requirements to impose variable gravity (including zero gravity) in order to assess the effects of gravity or the absence thereof on physical and physiological processes. The apparatus is expected to be especially useful for experiments on the effects of gravity on convection, boiling, and heat transfer in fluids and for experiments on mice to gain understanding of bone loss induced in human astronauts by prolonged exposure to reduced gravity in space flight. The maglev principle employed by the apparatus is well established. Diamagnetic cryogenic fluids such as liquid helium have been magnetically levitated for studying their phase transitions and critical behaviors. Biological entities consist mostly of diamagnetic molecules (e.g., water molecules) and thus can be levitated by use of sufficiently strong magnetic fields having sufficiently strong vertical gradients. The heart of the present maglev apparatus is a vertically oriented superconducting solenoid electromagnet (see figure) that generates a static magnetic field of about 16 T with a vertical gradient sufficient for levitation of water in normal Earth gravity. The electromagnet is enclosed in a Dewar flask having a volume of 100 L that contains liquid helium to maintain superconductivity. The Dewar flask features a 66-mm-diameter warm bore, lying within the bore of the magnet, wherein experiments can be performed at room temperature. The warm bore is accessible from its top and bottom ends. The superconducting electromagnet is run in the persistent mode, in which the supercurrent and the magnetic field can be maintained for weeks with little decay, making this apparatus extremely cost and energy efficient to operate. In addition to water, this apparatus can levitate several common fluids: liquid hydrogen, liquid oxygen, methane, ammonia, sodium, and lithium, all of which are useful, variously, as rocket fuels or as working fluids for heat transfer devices. A drop of water 45 mm in diameter and a small laboratory mouse have been levitated in this apparatus.

Extreme Events on a Low-Gradient River and Delta: Evidence for Sediment Mass Movements on the Subaqueous Delta and a Mechanism for Creating Hyperpycnal Flow onto the Shelf

NASA Astrophysics Data System (ADS)

Dellapenna, T. M.; Carlin, J. A.; Williams, J. R.

2016-02-01

The Brazos River empties into the Gulf of Mexico (GOM) forming a wave-influenced, muddy, subaqueous delta (SAD). Recent research in the estuarine reach of the river and on the SAD, however, found evidence for significant mass wasting of the delta-front and potential evidence of hyperpycnal flow, a processes typically associated with higher gradient and higher sediment yield rivers. The study used high-resolution geophysics on the SAD and water-column profiling in the lower river to investigate the transfer to and fate of fluvial sediment on the shelf. The SAD side scan mosaic combined with core data reveal that the eastern portion was dominated by exposed relict, consolidated sediment; an erosional scarp along the upper shoreface; and a thinning of the Holocene strata immediately downslope of the scarp. Holocene strata thickness increases into deeper water. These features suggest sediment mass wasting on the delta front. After rapidly prograding during the early and mid 20th century, reductions in sediment load due anthropogenic influences, and a shift in the primary depocenter lead to erosion on these abandoned portions of the delta. During an elevated fluvial discharge event, a >1 m thick fluid mud layer was found along a 6 km span of the river 2 km upstream from the mouth. The river's salt wedge was shown to inhibit sediment export from the river to the GOM, and facilitate deposition of mud in the lower river. We believe that the mud layer in the lower river builds during moderate and low discharge periods and remobilized during increased discharge, potentially resulting in hyperpyncnal flow to the shelf. We observed suspended sediment concentrations up to 100 g/l in the fluid mud layer during this event. While our observations did not capture the transition from fluid mud to hyperpycnal flow, we believe that with persistent increased discharge the fluid mud layer could transition to hyperpycnal flow.

Factors Involved in the Persistence of a Shiga Toxin-Producing Escherichia coli O157:H7 Strain in Bovine Feces and Gastro-Intestinal Content

PubMed Central

Segura, Audrey; Auffret, Pauline; Bibbal, Delphine; Bertoni, Marine; Durand, Alexandra; Jubelin, Grégory; Kérourédan, Monique; Brugère, Hubert; Bertin, Yolande; Forano, Evelyne

2018-01-01

Healthy cattle are the primary reservoir for O157:H7 Shiga toxin-producing E. coli responsible for human food-borne infections. Because farm environment acts as a source of cattle contamination, it is important to better understand the factors controlling the persistence of E. coli O157:H7 outside the bovine gut. The E. coli O157:H7 strain MC2, identified as a persistent strain in French farms, possessed the characteristics required to cause human infections and genetic markers associated with clinical O157:H7 isolates. Therefore, the capacity of E. coli MC2 to survive during its transit through the bovine gastro-intestinal tract (GIT) and to respond to stresses potentially encountered in extra-intestinal environments was analyzed. E. coli MC2 survived in rumen fluids, grew in the content of posterior digestive compartments and survived in bovine feces at 15°C predicting a successful transit of the bacteria along the bovine GIT and its persistence outside the bovine intestine. E. coli MC2 possessed the genetic information encoding 14 adherence systems including adhesins with properties related to colonization of the bovine intestine (F9 fimbriae, EhaA and EspP autotransporters, HCP pilus, FdeC adhesin) reflecting the capacity of the bacteria to colonize different segments of the bovine GIT. E. coli MC2 was also a strong biofilm producer when incubated in fecal samples at low temperature and had a greater ability to form biofilms than the bovine commensal E. coli strain BG1. Furthermore, in contrast to BG1, E. coli MC2 responded to temperature stresses by inducing the genes cspA and htrA during its survival in bovine feces at 15°C. E. coli MC2 also activated genes that are part of the GhoT/GhoS, HicA/HicB and EcnB/EcnA toxin/antitoxin systems involved in the response of E. coli to nutrient starvation and chemical stresses. In summary, the large number of colonization factors known to bind to intestinal epithelium and to biotic or abiotic surfaces, the capacity to produce biofilms and to activate stress fitness genes in bovine feces could explain the persistence of E. coli MC2 in the farm environment. PMID:29593666

Low protein content of drainage fluid is a good predictor for earlier chest tube removal after lobectomy.

PubMed

Olgac, Guven; Cosgun, Tugba; Vayvada, Mustafa; Ozdemir, Atilla; Kutlu, Cemal Asim

2014-10-01

Owing to the great absorption capability of the pleura for transudates, the protein content of draining pleural fluid may be considered as a more adequate determinant than its daily draining amount in the decision-making for earlier chest tube removal. In an a priori pilot study, we observed that the initially draining protein-rich exudate converts to a transudate quickly in most patients after lobectomies. Thus, chest tubes draining high-volume but low-protein fluids can safely be removed earlier in the absence of an air leak. This randomized study aims to investigate the validity and clinical applicability of this hypothesis as well as its influence on the timing for chest tube removal and earlier discharge after lobectomy. Seventy-two consecutive patients undergoing straightforward lobectomy were randomized into two groups. Patients with conditions affecting postoperative drainage and with persisting air leaks beyond the third postoperative day were excluded. Drains were removed if the pleural fluid to blood protein ratio (PrRPl/B) was ≤0.5, regardless of its daily draining amount in the study arm (Group S; n = 38), and patients in the control arm (Group C; n = 34) had their tubes removed if daily drainage was ≤250 ml regardless of its protein content. Patients were discharged home immediately or the following morning after removal of the last drain. All cases were followed up regarding the development of symptomatic pleural effusions and hospital readmissions for a redrainage procedure. Demographic and clinical characteristics as well as the pattern of decrease in PrRPl/B were the same between groups. The mean PrRPl/B was 0.65 and 0.67 (95% CI = 0.60-0.69 and 0.62-0.72) on the first postoperative day, and it remarkably dropped down to 0.39 and 0.33 (95% CI = 0.33-0.45 and 0.27-0.39) on the second day in Groups S and C, respectively, and remained below 0.5 on the third day (repeated-measures of ANOVA design, post hoc 'within-group' comparison of the first postoperative day versus second and third days; P < 0.002). Eleven of 38 (29%) and 16 of 27 (59%) patients' chest tubes were, respectively, removed on the first and second postoperative days in Group S, but only two of 34 (6%) and ten of 32 (31%) patients, respectively, had their chest tubes removed in Group C (two-tailed Fisher's exact test, P = 0.02 and 0.005 for the first and the second postoperative days, respectively). On the third postoperative day, daily drainage remained ≥250 ml in 22 (65%) patients, among whom, 17 (77%) would have their chest tubes removed on the PrRPl/B value in Group C. However, drains could not be removed due to the high protein content of draining fluid despite the acceptable volume of daily drainage in only three (27%) of 11 cases in Group S (McNemar's paired proportions test, P = 0.009). The mean chest tube removal time (2.1 ± 0.9 vs 2.9 ± 1.0 days; P < 0.001) and the median hospital stay [3 days (IQR: 1-3) vs 4 days (IQR: 2-4), P < 0.003] were significantly shorter in Group S. None of the patients required a redrainage procedure due to a persistent and symptomatic pleural effusion. Regardless of the daily drainage, chest tubes can safely be removed earlier than anticipated in most patients after lobectomy if the protein content of the draining fluid is low. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Abdominal wall sinus due to impacting gallstone during laparoscopic cholecystectomy: an unusual complication.

PubMed

Pavlidis, T E; Papaziogas, B T; Koutelidakis, I M; Papaziogas, T B

2002-02-01

During laparoscopic cholecystectomy, perforation of the gallbladder can occurs in < or = 20% of cases, while gallstone spillage occurs in < or = 6% of cases. In most cases, there are no consequences. Gallstones can be lost in the abdominal wall as well as the abdomen during extraction of the gallbladder. The fate of such lost gallstones, which can lead to the formation of an abscess, an abdominal wall mass, or a persistent sinus, has not been studied adequately. Herein we report the case of a persistent sinus of the abdominal wall after an emergent laparoscopic cholecystectomy in an 82-year-old woman with gangrenous cholecystitis and perforation of the friable wall in association with an empyema of the gallbladder. The culture of the obtained pus was positive for Escherichia coli. After a small leak of dirty fluid from the wound of the epigastric port site of 4 months' duration, surgical exploration under local anesthesia revealed that the sinus was caused by spilled gallstones impacting into the abdominal wall between the posterior sheath and left rectus abdominalis muscle. The removal of the stones resulted in complete healing. Long-term complications after laparoscopic cholecystectomy involving the abdominal wall are rare but important possible consequences that could be avoided.

Brownian trail rectified

NASA Astrophysics Data System (ADS)

Hurd, Alan J.; Ho, Pauline

The experiments described here indicate when one of Nature's best fractals -- the Brownian trail -- becomes nonfractal. In most ambient fluids, the trail of a Brownian particle is self-similar over many decades of length. For example, the trail of a submicron particle suspended in an ordinary liquid, recorded at equal time intervals, exhibits apparently discontinuous changes in velocity from macroscopic lengths down to molecular lengths: the trail is a random walk with no velocity memory from one step to the next. In ideal Brownian motion, the kinks in the trail persist to infinitesimal time intervals, i.e., it is a curve without tangents. Even in real Brownian motion in a liquid, the time interval must be shortened to approximately 10(-8) s before the velocity appears continuous. In sufficiently rarefied environments, this time resolution at which a Brownian trail is rectified from a curve without tangents to a smoothly varying trajectory is greatly lengthened, making it possible to study the kinetic regime by dynamic light scattering. Our recent experiments with particles in a plasma have demonstrated this capability. In this regime, the particle velocity persists over a finite step length allowing an analogy to an ideal gas with Maxwell-Boltzmann velocities; the particle mass could be obtained from equipartition. The crossover from ballistic flight to hydrodynamic diffusion was also seen.

Immunoprofiles of human Sertoli cells infected with Zika virus reveals unique insights into host-pathogen crosstalk.

PubMed

Strange, Daniel P; Green, Richard; Siemann, David N; Gale, Michael; Verma, Saguna

2018-06-07

Confirmed reports of Zika virus (ZIKV) in seminal fluid months after clearance of viremia suggests that ZIKV can establish persistent infection in the seminiferous tubules, an immune privileged site of the testis. The seminiferous tubule epithelium is mainly composed of Sertoli cells that function to nourish and protect developing germ cells. We recently demonstrated that primary human Sertoli cells (hSeC) were highly susceptible to ZIKV as compared to dengue virus without causing cell death and thus may act as a reservoir for ZIKV in the testes. However, the cellular and immune responses of hSeC to infection with ZIKV or any other virus are not yet characterized. Using genome-wide RNA-seq to compare immunoprofiles of hSeC, we show that the most prominent response to ZIKV at early stage of infection was suppression of cell growth and proliferation functional pathways. Peak virus replication was associated with induction of multiple antiviral defense pathways. Unique ZIKV-associated signatures included dysregulation of germ cell-Sertoli cell junction signaling. This study demonstrates that hSeC are capable of signaling through canonical pro-inflammatory pathways and provides insights into unique cell-type-specific response induced by ZIKV in association with viral persistence in the testes.

Herpes Simplex Virus Suppressive Therapy in Herpes Simplex Virus-2/Human Immunodeficiency Virus-1 Coinfected Women Is Associated With Reduced Systemic CXCL10 But Not Genital Cytokines.

PubMed

Andersen-Nissen, Erica; Chang, Joanne T; Thomas, Katherine K; Adams, Devin; Celum, Connie; Sanchez, Jorge; Coombs, Robert W; McElrath, M Juliana; Baeten, Jared M

2016-12-01

Herpes simplex virus type-2 (HSV-2) may heighten immune activation and increase human immunodeficiency virus 1 (HIV-1) replication, resulting in greater infectivity and faster HIV-1 disease progression. An 18-week randomized, placebo-controlled crossover trial of 500 mg valacyclovir twice daily in 20 antiretroviral-naive women coinfected with HSV-2 and HIV-1 was conducted and HSV-2 suppression was found to significantly reduce both HSV-2 and HIV-1 viral loads both systemically and the endocervical compartment. To determine the effect of HSV-2 suppression on systemic and genital mucosal inflammation, plasma specimens, and endocervical swabs were collected weekly from volunteers in the trial and cryopreserved. Plasma was assessed for concentrations of 31 cytokines and chemokines; endocervical fluid was eluted from swabs and assayed for 14 cytokines and chemokines. Valacyclovir significantly reduced plasma CXCL10 but did not significantly alter other cytokine concentrations in either compartment. These data suggest genital tract inflammation in women persists despite HSV-2 suppression, supporting the lack of effect on transmission seen in large scale efficacy trials. Alternative therapies are needed to reduce persistent mucosal inflammation that may enhance transmission of HSV-2 and HIV-1.

Studies of perturbed three vortex dynamics

NASA Astrophysics Data System (ADS)

Blackmore, Denis; Ting, Lu; Knio, Omar

2007-06-01

It is well known that the dynamics of three point vortices moving in an ideal fluid in the plane can be expressed in Hamiltonian form, where the resulting equations of motion are completely integrable in the sense of Liouville and Arnold. The focus of this investigation is on the persistence of regular behavior (especially periodic motion) associated with completely integrable systems for certain (admissible) kinds of Hamiltonian perturbations of the three vortex system in a plane. After a brief survey of the dynamics of the integrable planar three vortex system, it is shown that the admissible class of perturbed systems is broad enough to include three vortices in a half plane, three coaxial slender vortex rings in three space, and "restricted" four vortex dynamics in a plane. Included are two basic categories of results for admissible perturbations: (i) general theorems for the persistence of invariant tori and periodic orbits using Kolmogorov-Arnold-Moser- and Poincaré-Birkhoff-type arguments and (ii) more specific and quantitative conclusions of a classical perturbation theory nature guaranteeing the existence of periodic orbits of the perturbed system close to cycles of the unperturbed system, which occur in abundance near centers. In addition, several numerical simulations are provided to illustrate the validity of the theorems as well as indicating their limitations as manifested by transitions to chaotic dynamics.

Intensity ratio to improve black hole assessment in multiple sclerosis.

PubMed

Adusumilli, Gautam; Trinkaus, Kathryn; Sun, Peng; Lancia, Samantha; Viox, Jeffrey D; Wen, Jie; Naismith, Robert T; Cross, Anne H

2018-01-01

Improved imaging methods are critical to assess neurodegeneration and remyelination in multiple sclerosis. Chronic hypointensities observed on T1-weighted brain MRI, "persistent black holes," reflect severe focal tissue damage. Present measures consist of determining persistent black holes numbers and volumes, but do not quantitate severity of individual lesions. Develop a method to differentiate black and gray holes and estimate the severity of individual multiple sclerosis lesions using standard magnetic resonance imaging. 38 multiple sclerosis patients contributed images. Intensities of lesions on T1-weighted scans were assessed relative to cerebrospinal fluid intensity using commercial software. Magnetization transfer imaging, diffusion tensor imaging and clinical testing were performed to assess associations with T1w intensity-based measures. Intensity-based assessments of T1w hypointensities were reproducible and achieved > 90% concordance with expert rater determinations of "black" and "gray" holes. Intensity ratio values correlated with magnetization transfer ratios (R = 0.473) and diffusion tensor imaging metrics (R values ranging from 0.283 to -0.531) that have been associated with demyelination and axon loss. Intensity ratio values incorporated into T1w hypointensity volumes correlated with clinical measures of cognition. This method of determining the degree of hypointensity within multiple sclerosis lesions can add information to conventional imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Implicit Valuation of the Near-Miss is Dependent on Outcome Context.

PubMed

Banks, Parker J; Tata, Matthew S; Bennett, Patrick J; Sekuler, Allison B; Gruber, Aaron J

2018-03-01

Gambling studies have described a "near-miss effect" wherein the experience of almost winning increases gambling persistence. The near-miss has been proposed to inflate the value of preceding actions through its perceptual similarity to wins. We demonstrate here, however, that it acts as a conditioned stimulus to positively or negatively influence valuation, dependent on reward expectation and cognitive engagement. When subjects are asked to choose between two simulated slot machines, near-misses increase valuation of machines with a low payout rate, whereas they decrease valuation of high payout machines. This contextual effect impairs decisions and persists regardless of manipulations to outcome feedback or financial incentive provided for good performance. It is consistent with proposals that near-misses cause frustration when wins are expected, and we propose that it increases choice stochasticity and overrides avoidance of low-valued options. Intriguingly, the near-miss effect disappears when subjects are required to explicitly value machines by placing bets, rather than choosing between them. We propose that this task increases cognitive engagement and recruits participation of brain regions involved in cognitive processing, causing inhibition of otherwise dominant systems of decision-making. Our results reveal that only implicit, rather than explicit strategies of decision-making are affected by near-misses, and that the brain can fluidly shift between these strategies according to task demands.

One-Year Outcomes of Aflibercept in Recurrent or Persistent Neovascular Age-Related Macular Degeneration

PubMed Central

Arcinue, Cheryl A.; Ma, Feiyan; Barteselli, Giulio; Sharpsten, Lucie; Gomez, Maria Laura; Freeman, William R.

2014-01-01

Purpose To evaluate 6-month and 1-year outcomes of every 8 weeks (Q8W) aflibercept in patients with resistant neovascular age-related macular degeneration (AMD). Design Retrospective, interventional, consecutive case series. Methods Retrospective review of patients with resistance (multiple recurrences or persistent exudation) to every 4 weeks (Q4W) ranibizumab or bevacizumab that were switched to Q8W aflibercept. Results Sixty-three eyes of 58 patients had a median of 13 (interquartile range (IQR), 7-22) previous anti Vascular Endothelial Growth Factor (anti-VEGF) injections. At 6-months after changing to aflibercept, 60.3% of eyes were completely dry, which was maintained up to one-year. The median maximum retinal thickness improved from 355 microns to 269 microns at 6 months (p<0.0001) and 248 microns at one year (p<0.0001). There was no significant improvement in ETDRS visual acuity at 6 months (p=0.2559) and one-year follow-up (p=0.1081) compared with baseline. The mean difference in ETDRS visual acuity compared to baseline at 6 months was −0.05 logMAR (+2.5 letters) and 0.04 logMAR at 1 year (−2 letters). Conclusion Sixty percent of eyes with resistant AMD while on Q4W ranibizumab or bevacizumab were completely dry after changing to Q8W aflibercept at the 6-month and 1-year follow-ups, but visual acuity did not significantly improve. Only a third of eyes needed to be switched from Q8W to Q4W aflibercept due to persistence of fluid; Q8W dosing of aflibercept without the initial 3 monthly loading doses may be a good alternative in a select group of patients who may have developed ranibizumab or bevacizumab resistance. PMID:25461263

Detection of Foot-and-mouth Disease Virus RNA and Capsid Protein in Lymphoid Tissues of Convalescent Pigs Does Not Indicate Existence of a Carrier State.

PubMed

Stenfeldt, C; Pacheco, J M; Smoliga, G R; Bishop, E; Pauszek, S J; Hartwig, E J; Rodriguez, L L; Arzt, J

2016-04-01

A systematic study was performed to investigate the potential of pigs to establish and maintain persistent foot-and-mouth disease virus (FMDV) infection. Infectious virus could not be recovered from sera, oral, nasal or oropharyngeal fluids obtained after resolution of clinical infection with any of five FMDV strains within serotypes A, O and Asia-1. Furthermore, there was no isolation of live virus from tissue samples harvested at 28-100 days post-infection from convalescent pigs recovered from clinical or subclinical FMD. Despite lack of detection of infectious FMDV, there was a high prevalence of FMDV RNA detection in lymph nodes draining lesion sites harvested at 35 days post-infection, with the most frequent detection recorded in popliteal lymph nodes (positive detection in 88% of samples obtained from non-vaccinated pigs). Likewise, at 35 dpi, FMDV capsid antigen was localized within follicles of draining lymph nodes, but without concurrent detection of FMDV non-structural protein. There was a marked decline in the detection of FMDV RNA and antigen in tissue samples by 60 dpi, and no antigen or viral RNA could be detected in samples obtained at 100 dpi. The data presented herein provide the most extensive investigation of FMDV persistence in pigs. The overall conclusion is that domestic pigs are unlikely to be competent long-term carriers of infectious FMDV; however, transient persistence of FMDV protein and RNA in lymphoid tissues is common following clinical or subclinical infection. © Published 2014. This article is a US Government work and is in the public domain in the USA.

An analytical biomarker for treatment of patients with recurrent B-ALL after remission induced by infusion of anti-CD19 chimeric antigen receptor T (CAR-T) cells.

PubMed

Zhang, Yajing; Zhang, Wenying; Dai, Hanren; Wang, Yao; Shi, Fengxia; Wang, Chunmeng; Guo, Yelei; Liu, Yang; Chen, Meixia; Feng, Kaichao; Zhang, Yan; Liu, Chuanjie; Yang, Qingming; Li, Suxia; Han, Weidong

2016-04-01

Anti-CD19 chimeric antigen receptor-modified T (CAR-T-19) cells have emerged as a powerful targeted immunotherapy for B-cell lineage acute lymphoblastic leukemia with a remarkable clinical response in recent trials. Nonetheless, few data are available on the subsequent clinical monitoring and treatment of the patients, especially those with disease recurrence after CAR-T-19 cell infusion. Here, we analyzed three patients who survived after our phase I clinical trial and who were studied by means of biomarkers reflecting persistence of CAR-T-19 cells in vivo and predictive factors directing further treatment. One patient achieved 9-week sustained complete remission and subsequently received an allogeneic hematopoietic stem cell transplant. Another patient who showed relapse after 20 weeks without detectable leukemia in the cerebrospinal fluid after CAR-T-19 cell treatment was able to achieve a morphological remission under the influence of stand-alone low-dose chemotherapeutic agents. The third patient gradually developed extensive extramedullary involvement in tissues with scarce immune- cell infiltration during a long period of hematopoietic remission after CAR-T-19 cell therapy. Long-term and discontinuous increases in serum cytokines (mainly interleukin 6 and C-reactive protein) were identified in two patients (Nos. 1 and 6) even though only a low copy number of CAR molecules could be detected in their peripheral blood. This finding was suggestive of persistent functional activity of CAR-T-19 cells. Combined analyses of laboratory biomarkers with their clinical manifestations before and after salvage treatment showed that the persistent immunosurveillance mediated by CAR-T-19 cells would inevitably potentiate the leukemia-killing effectiveness of subsequent chemotherapy in patients who showed relapse after CAR-T-19-induced remission.

Wake-Vortex Hazards During Cruise

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.; James, Kevin D.; Nixon, David (Technical Monitor)

1998-01-01

Even though the hazard posed by lift-generated wakes of subsonic transport aircraft has been studied extensively for approach and departure at airports, only a small amount of effort has gone into the potential hazard at cruise altitude. This paper reports on a studio of the wake-vortex hazard during cruise because encounters may become more prevalent when free-flight becomes available and each aircraft, is free to choose its own route between destinations. In order to address the problem, the various fluid-dynamic stages that vortex wakes usually go through as they age will be described along with estimates of the potential hazard that each stage poses. It appears that a rolling-moment hazard can be just as severe at cruise as for approach at airports, but it only persists for several minutes. However, the hazard posed by the downwash in the wake due to the lift on the generator aircraft persists for tens of minutes in a long narrow region behind the generating aircraft. The hazard consists of severe vertical loads when an encountering aircraft crosses the wake. A technique for avoiding vortex wakes at cruise altitude will be described. To date the hazard posed by lift-generated vortex wakes and their persistence at cruise altitudes has been identified and subdivided into several tasks. Analyses of the loads to be encounter and are underway and should be completed shortly. A review of published literature on the subject has been nearly completed (see text) and photographs of vortex wakes at cruise altitudes have been taken and the various stages of decay have been identified. It remains to study and sort the photographs for those that best illustrate the various stages of decay after they are shed by subsonic transport aircraft at cruise altitudes. The present status of the analysis and the paper are described.

Making a frothy shampoo or beer

NASA Astrophysics Data System (ADS)

Durian, Douglas

2011-03-01

The terms ``foam'' and ``froth'' refer to a dispersion of gas bubbles in a liquid. Why do certain liquids show a tendency to foam while others do not? For example, bubbles can be produced in pure water by vigorous agitation, but then they rapidly coalesce and disappear. While foams cannot be produced with pure water, foams associated with beer or shampoo can persist for several minutes or even hours. What ingredient(s) in shampoo and beer make their foams stable, and what physical concepts control their stability? In this talk I'll review three basic mechanisms underlying foam stability, and I'll make connection with current research on coarsening by the diffusion of gas from smaller to larger bubbles. With thanks to Srinivasa Raghavan, Adam Roth, and NASA Microgravity Fluid Physics Grant NNX07AP20G.

Using Metabolomics to Investigate Biomarkers of Drug Addiction.

PubMed

Ghanbari, Reza; Sumner, Susan

2018-02-01

Drug addiction has been associated with an increased risk for cancer, psychological complications, heart, liver, and lung disease, as well as infection. While genes have been identified that can mark individuals at risk for substance abuse, the initiation step of addiction is attributed to persistent metabolic disruptions occurring following the first instance of narcotic drug use. Advances in analytical technologies can enable the detection of thousands of signals in body fluids and excreta that can be used to define biochemical profiles of addiction. Today, these approaches hold promise for determining how exposure to drugs, in the absence or presence of other environmentally relevant factors, can impact human metabolism. We posit that these can lead to candidate biomarkers of drug dependence, treatment, withdrawal, or relapse. Copyright © 2017. Published by Elsevier Ltd.

Immune complexes and Ross River virus disease (epidemic polyarthritis).

PubMed

Fraser, J R; Cunningham, A L; Mathews, J D; Riglar, A

1988-01-01

Immune complexes were sought in serum and synovial fluid in Ross River virus disease (epidemic polyarthritis). Multiple samples from 15 patients showing varied degrees of disease activity over a 3 month period were analysed for their content of complement components C3 and C4, and for C1q solid-phase and Raji cell binding activity. Levels of C3 and C1q binding activity were normal. C4 and Raji cell binding activity were normal except for three high levels of Raji cell binding, of which two were accompanied by low levels of C4, with normal C3 and C1q binding. Synovial fluid showed anomalous Raji cell reactivity of uncertain significance. Conglutinin solid-phase binding activity and IgG rheumatoid factor were compared in the serum of 20 patients during active disease and after recovery. The results were identical and within the normal range in both phases. One patient developed IgM rheumatoid factor in a low titre late in his illness. Although these findings do not entirely exclude a role for immune complexes formed at the onset in the circulation or tissues, it is concluded from this and other evidence that circulating complexes are not commonly responsible for the persistence of syndromes in this disease.

Acute and chronic effects of SGLT2 blockade on glomerular and tubular function in the early diabetic rat

PubMed Central

Rieg, Timo; Miracle, Cynthia; Mansoury, Hadi; Whaley, Jean; Vallon, Volker; Singh, Prabhleen

2012-01-01

Tubuloglomerular feedback (TGF) stabilizes nephron function from minute to minute and adapts to different steady-state inputs to maintain this capability. Such adaptation inherently renders TGF less efficient at buffering long-term disturbances, but the magnitude of loss is unknown. We undertook the present study to measure the compromise between TGF and TGF adaptation in transition from acute to chronic decline in proximal reabsorption (Jprox). As a tool, we blocked proximal tubule sodium-glucose cotransport with the SGLT2 blocker dapagliflozin in hyperglycemic rats with early streptozotocin diabetes, a condition in which a large fraction of proximal fluid reabsorption owes to SGLT2. Dapagliflozin acutely reduced proximal reabsorption leading to a 70% increase in early distal chloride, a saturated TGF response, and a major reduction in single nephron glomerular filtration rate (SNGFR). Acute and chronic effects on Jprox were indistinguishable. Adaptations to 10–12 days of dapagiflozin included increased reabsorption by Henle's loop, which caused a partial relaxation in the increased tone exerted by TGF that could be explained without desensitization of TGF. In summary, TGF contributes to long-term fluid and salt balance by mediating a persistent decline in SNGFR as the kidney adapts to a sustained decrease in Jprox. PMID:21940401

Unlocking the potential of supported liquid phase catalysts with supercritical fluids: low temperature continuous flow catalysis with integrated product separation

PubMed Central

Franciò, Giancarlo; Hintermair, Ulrich; Leitner, Walter

2015-01-01

Solution-phase catalysis using molecular transition metal complexes is an extremely powerful tool for chemical synthesis and a key technology for sustainable manufacturing. However, as the reaction complexity and thermal sensitivity of the catalytic system increase, engineering challenges associated with product separation and catalyst recovery can override the value of the product. This persistent downstream issue often renders industrial exploitation of homogeneous catalysis uneconomical despite impressive batch performance of the catalyst. In this regard, continuous-flow systems that allow steady-state homogeneous turnover in a stationary liquid phase while at the same time effecting integrated product separation at mild process temperatures represent a particularly attractive scenario. While continuous-flow processing is a standard procedure for large volume manufacturing, capitalizing on its potential in the realm of the molecular complexity of organic synthesis is still an emerging area that requires innovative solutions. Here we highlight some recent developments which have succeeded in realizing such systems by the combination of near- and supercritical fluids with homogeneous catalysts in supported liquid phases. The cases discussed exemplify how all three levels of continuous-flow homogeneous catalysis (catalyst system, separation strategy, process scheme) must be matched to locate viable process conditions. PMID:26574523

Impact of bile salt adaptation of Lactobacillus delbrueckii subsp. lactis 200 on its interaction capacity with the gut.

PubMed

Burns, Patricia; Reinheimer, Jorge; Vinderola, Gabriel

2011-10-01

In a previous work, bile-salt-resistant derivatives were obtained from non-intestinal lactobacilli. The aim of this work was to investigate the impact of bile adaptation of Lactobacillus delbrueckii subsp. lactis 200 on morphology, surface properties, in vivo interaction capacity with the gut and ability to activate the gut immune response. Electron microscopy studies, growth kinetics in the presence of bovine and porcine bile, the capacity to deconjugate bile acids, hydrophobicity, autoaggregation and co-aggregation capacities were studied for the parental strain and its bile-resistant derivative in vitro. Additionally, survival in intestinal fluid, the interaction with the gut and the immunomodulating capacities were studied in mice. Bile salt adaptation conferred upon the adapted strain a higher capacity to withstand physiological concentrations of bile salts and greater survival capacity in intestinal fluid. However, bile salt exposure reduced cell hydrophobicity, autoaggregation and adhesion capacities, resulting in reduced persistence in the intestinal lumen and delayed capacity to activate the gut immune response. Insight into the effects of bile salts upon the interaction and immunomodulating capacity of lactobacilli with the gut is provided, relating in vitro and in vivo results. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Unlocking the potential of supported liquid phase catalysts with supercritical fluids: low temperature continuous flow catalysis with integrated product separation.

PubMed

Franciò, Giancarlo; Hintermair, Ulrich; Leitner, Walter

2015-12-28

Solution-phase catalysis using molecular transition metal complexes is an extremely powerful tool for chemical synthesis and a key technology for sustainable manufacturing. However, as the reaction complexity and thermal sensitivity of the catalytic system increase, engineering challenges associated with product separation and catalyst recovery can override the value of the product. This persistent downstream issue often renders industrial exploitation of homogeneous catalysis uneconomical despite impressive batch performance of the catalyst. In this regard, continuous-flow systems that allow steady-state homogeneous turnover in a stationary liquid phase while at the same time effecting integrated product separation at mild process temperatures represent a particularly attractive scenario. While continuous-flow processing is a standard procedure for large volume manufacturing, capitalizing on its potential in the realm of the molecular complexity of organic synthesis is still an emerging area that requires innovative solutions. Here we highlight some recent developments which have succeeded in realizing such systems by the combination of near- and supercritical fluids with homogeneous catalysts in supported liquid phases. The cases discussed exemplify how all three levels of continuous-flow homogeneous catalysis (catalyst system, separation strategy, process scheme) must be matched to locate viable process conditions. © 2015 The Authors.

Can a fractured caprock self-heal?

NASA Astrophysics Data System (ADS)

Elkhoury, Jean E.; Detwiler, Russell L.; Ameli, Pasha

2015-05-01

The ability of geologic seals to prevent leakage of fluids injected into the deep subsurface is critical for mitigating risks associated with greenhouse-gas sequestration and natural-gas production. Fractures caused by tectonic or injection-induced stresses create potential leakage pathways that may be further enhanced by mineral dissolution. We present results from reactive-flow experiments in fractured caprock (dolomitic anhydrite), where additional dissolution occurs in the rock matrix adjacent to the fracture surfaces. Preferential dissolution of anhydrite left a compacted layer of dolomite in the fractures. At lower flow rate, rock-fluid reactions proceeded to near equilibrium within the fracture with preferential flow paths persisting over the 6-month duration of the experiment and a negligible change in permeability. At higher flow rate, permeability decreased by a dramatic two orders of magnitude. This laboratory-scale observation of self-healing argues against the likelihood of runaway permeability growth in fractured porous caprock composed of minerals with different solubilities and reaction kinetics. However, scaling arguments suggest that at larger length scales this self-healing process may be offset by the formation of dissolution channels. Our results have relevance beyond the greenhouse-gas sequestration problem. Chemical disequilibrium at waste injection sites and in hydrothermal reservoirs will lead to reactive flows that may also significantly alter formation permeability.

Idiopathic intracranial hypertension: ongoing clinical challenges and future prospects

PubMed Central

Julayanont, Parunyou; Karukote, Amputch; Ruthirago, Doungporn; Panikkath, Deepa; Panikkath, Ragesh

2016-01-01

Idiopathic intracranial hypertension (IIH) is an uncommon disorder characterized by increased intracranial pressure without radiological or laboratory evidence of intracranial pathology except empty sella turcica, optic nerve sheath with filled out cerebrospinal fluid spaces, and smooth-walled nonflow-related venous sinus stenosis or collapse. This condition typically affects obese women. The incidence of IIH is increasing with the rising prevalence of obesity. Persistent headache is the most common symptom. Visual impairment is a serious complication that may not be recognized by the patients. This paper reviews clinical manifestations, diagnostic challenges, and current treatments of IIH in adults. Various imaging modalities have been studied on their validity for detection of IIH and papilledema. This review also includes new studies on medical, surgical, and interventional management of this condition. Acetazolamide and topiramate are the only two medications that have been studied in randomized controlled trials about their efficacy in treatment of IIH. In patients who have severe visual impairment or progressive visual deterioration despite medical management, surgical or interventional treatment may be considered. The efficacy and complications of cerebrospinal fluid diversion, optic nerve sheath fenestration, and endovascular venous stenting reported in the last 3 decades have been summarized in this review. Finally, the prospective aspects of biomarkers and treatments are proposed for future research. PMID:26929666

Numerical simulation of hydrodynamic processes beneath a wind-driven water surface

NASA Astrophysics Data System (ADS)

Tsai, Wu-ting

Turbulent flow driven by a constant wind stress acting at the water surface was simulated numerically to gain a better understanding of the hydrodynamic processes governing the transfer of slightly soluble gases across the atmosphere-water interfaces. Simulation results show that two distinct flow features, attributed to subsurface surface renewal eddies, appear at the water surface. The first characteristic feature is surface streaming, which consists of high-speed streaks aligned with the wind stress. Floating Lagrangian particles, which are distributed uniformly at the water surface, merge to the predominantly high-speed streaks and form elongated streets immediately after they are released. The second characteristic surface signatures are localized low-speed spots which emerge randomly at the water surface. A high-speed streak bifurcates and forms a dividing flow when it encounters a low-speed surface spot. These coherent surface flow structures are qualitatively identical to those observed in the experiment of Melville et al. [1998]. The persistence of these surface features also suggests that there must exist organized subsurface vortical structures that undergo autonomous generation cycles maintained by self-sustaining mechanisms. These coherent vortical flows serve as the renewal eddies that pump the submerged fluids toward the water surface and bring down the upper fluids, and therefore enhance the scalar exchange between the atmosphere and the water body.

Shoaling internal solitary waves of depression over gentle slopes

NASA Astrophysics Data System (ADS)

Rivera, Gustavo; Diamessis, Peter

2017-11-01

The shoaling of an internal solitary wave (ISW) of depression over gentle slopes is explored through fully nonlinear and non-hydrostatic simulations using a high resolution/accuracy deformed spectral multidomain penalty method. During shoaling, the wave does not disintegrate as in the case of steeper slope but, instead, maintains its symmetric shape. At the core of the wave, an unstable region forms, characterized by the entrapment of heavier-over-light fluid. The formation of this convective instability is attributed to the vertical stretching by the ISW of the near-surface vorticity layer associated with the baroclinic background current. According to recent field observations in the South China Sea, the unstable region drives localized turbulent mixing within the wave, estimated to be up to four times larger than that in the open ocean, in the form of a recirculating trapped core. In this talk, emphasis is placed on the structure of the unstable region and the persistence of a possible recirculating core using simulations which capture 2D wave propagation combined with 3D representation of the transition to turbulence. As such, a preliminary understanding of the underlying fluid mechanics and the potential broader oceanic significance of ISWs with trapped cores is offered. Financial support gratefully acknowledged to NSF OCE Grant 1634257.

Long-term evaluation of a new ventriculoperitoneal shunt valve system in a dog.

PubMed

Filgueiras, Richard da Rocha; Martins, Christine de Souza; de Almeida, Ricardo Miyasaka; Silva, Rosana Marques; da Rocha, Martha de Souza Teixeira; Firmino, Fernanda de Paula; Maguilnik, Samara; Medeiros, Luíza Quintão

2009-12-01

To report on the use of a new ventriculoperitoneal shunt (VPS) valve system utilized in a dog with hydrocephalus and to describe the clinical course over 20 months after implantation. A 3-month-old female Lhasa Apso dog was presented with lateral strabismus, domed calvarium, and visual deficits. A lateral skull radiograph revealed a persistent fontanelle. Transfontanellar ultrasonographic examination and computed tomographic examination showed excessive accumulation of fluid within the ventricles. The owner had observed symptoms as early as 1 month after birth, suggesting congenital hydrocephalus. A VPS with a new valve system that inhibits cerebrospinal fluid overdrainage and obstruction of the catheter was implanted. The dog showed clinical improvement 48 hours after the procedure. Twenty days after shunt implantation, another computed tomography scan was performed that showed reduction in ventricle size. The evaluation of VPS patency was carried out 20 months after surgery and demonstrated that the system was working properly without obstruction. There are reports in the literature describing the use of several devices to perform VPS in dogs. A new device not previously described in the veterinary literature was used in this case report, and according to the manufacturer's description, this device inhibits proteinaceous build-up, which is usually responsible for subsequent catheter obstructions.

Universal linear-temperature resistivity: possible quantum diffusion transport in strongly correlated superconductors.

PubMed

Hu, Tao; Liu, Yinshang; Xiao, Hong; Mu, Gang; Yang, Yi-Feng

2017-08-25

The strongly correlated electron fluids in high temperature cuprate superconductors demonstrate an anomalous linear temperature (T) dependent resistivity behavior, which persists to a wide temperature range without exhibiting saturation. As cooling down, those electron fluids lose the resistivity and condense into the superfluid. However, the origin of the linear-T resistivity behavior and its relationship to the strongly correlated superconductivity remain a mystery. Here we report a universal relation [Formula: see text], which bridges the slope of the linear-T-dependent resistivity (dρ/dT) to the London penetration depth λ L at zero temperature among cuprate superconductor Bi 2 Sr 2 CaCu 2 O 8+δ and heavy fermion superconductors CeCoIn 5 , where μ 0 is vacuum permeability, k B is the Boltzmann constant and ħ is the reduced Planck constant. We extend this scaling relation to different systems and found that it holds for other cuprate, pnictide and heavy fermion superconductors as well, regardless of the significant differences in the strength of electronic correlations, transport directions, and doping levels. Our analysis suggests that the scaling relation in strongly correlated superconductors could be described as a hydrodynamic diffusive transport, with the diffusion coefficient (D) approaching the quantum limit D ~ ħ/m*, where m* is the quasi-particle effective mass.

Paternal preconception ethanol exposure blunts hypothalamic-pituitary-adrenal axis responsivity and stress-induced excessive fluid intake in male mice.

PubMed

Rompala, Gregory R; Finegersh, Andrey; Homanics, Gregg E

2016-06-01

A growing number of environmental insults have been shown to induce epigenetic effects that persist across generations. For instance, paternal preconception exposures to ethanol or stress have independently been shown to exert such intergenerational effects. Since ethanol exposure is a physiological stressor that activates the hypothalamic-pituitary-adrenal (HPA) axis, we hypothesized that paternal ethanol exposure would impact stress responsivity of offspring. Adult male mice were exposed to chronic intermittent vapor ethanol or control conditions for 5 weeks before being mated with ethanol-naïve females to produce ethanol (E)- and control (C)-sired offspring. Adult male and female offspring were tested for plasma corticosterone (CORT) levels following acute restraint stress and the male offspring were further examined for stress-evoked 2-bottle choice ethanol-drinking. Paternal ethanol exposure blunted plasma CORT levels following acute restraint stress selectively in male offspring; females were unaffected. In a stress-evoked ethanol-drinking assay, there was no effect of stress on ethanol consumption. However, C-sired males exhibited increased total fluid intake (polydipsia) in response to stress while E-sired males were resistant to this stress-induced phenotype. Taken together, these data suggest that paternal ethanol exposure imparts stress hyporesponsivity to male offspring. Copyright © 2016 Elsevier Inc. All rights reserved.

Paternal preconception ethanol exposure blunts hypothalamic-pituitary-adrenal axis responsivity and stress-induced excessive fluid intake in male mice

PubMed Central

Rompala, Gregory R.; Finegersh, Andrey; Homanics, Gregg E.

2016-01-01

A growing number of environmental insults have been shown to induce epigenetic effects that persist across generations. For instance, paternal preconception exposures to ethanol or stress have independently been shown to exert such intergenerational effects. Since ethanol exposure is a physiological stressor that activates the hypothalamic-pituitary-adrenal (HPA) axis, we hypothesized that paternal ethanol exposure would impact stress responsivity of offspring. Adult male mice were exposed to chronic intermittent vapor ethanol or control conditions for 5 weeks before being mated with ethanol-naïve females to produce ethanol (E)- and control (C)-sired offspring. Adult male and female offspring were tested for plasma corticosterone (CORT) levels following acute restraint stress and the male offspring were further examined for stress-evoked 2-bottle choice ethanol drinking. Paternal ethanol exposure blunted plasma CORT levels following acute restraint stress selectively in male offspring; females were unaffected. In a stress-evoked ethanol-drinking assay, there was no effect of stress on ethanol consumption. However, C-sired males exhibited increased total fluid intake (polydipsia) in response to stress while E-sired males were resistant to this stress-induced phenotype. Taken together, these data suggest that paternal ethanol exposure imparts stress hyporesponsivity to male offspring. PMID:27286933

Long-term outcomes of pars plana vitrectomy without internal limiting membrane peeling for optic disc pit maculopathy.

PubMed

Avci, R; Yilmaz, S; Inan, U U; Kaderli, B; Kurt, M; Yalcinbayir, O; Yildiz, M; Yucel, A

2013-12-01

To evaluate the results of surgical treatment of maculopathy secondary to congenital optic pit anomaly with pars plana vitrectomy (PPV), endolaser to the temporal edge of the optic disc and C3F8 tamponade without internal limiting membrane (ILM) peeling. Thirteen eyes of 12 patients with serous macular detachment and/or macular retinoschisis secondary to congenital optic disc pit (ODP) were included in the study. All eyes underwent PPV, posterior hyaloid removal, endolaser photocoagulation on the temporal margin of the optic disc and 12% C3F8 gas tamponade. Anatomic success and functional outcome determined retrospectively by optical coherence tomography and measurement of best corrected visual acuity (BCVA), respectively were the main outcome parameters. Two lines or more improvement in BCVA was obtained in 11 eyes and 6 of these eyes had 20/40 or better BCVA at the final visit. Subretinal or intraretinal fluid was completely resorbed postoperatively in 12 eyes but a little intraretinal fluid persisted in one eye at the 16-month follow-up. Better visual improvement was observed in patients treated by earlier surgical intervention. PPV, C3F8 gas tamponade and endolaser to the optic disc margin without ILM peeling may yield favourable results in the treatment of ODP maculopathy.

Vanishing calcification associated with a spontaneous ventral spinal cerebrospinal fluid leak.

PubMed

Schievink, Wouter I; Ross, Lindsey; Prasad, Ravi S; Maya, M Marcel

2016-12-01

Some patients with spontaneous intracranial hypotension have a ventral spinal cerebrospinal fluid (CSF) leak and these CSF leaks may be associated with calcified disk herniations. Identifying these calcifications is helpful in directing treatment. We report here the unusual case of a patient with a ventral CSF leak in whom the associated calcification absorbed over a five-month period. A 42-year-old woman developed orthostatic headaches and bilateral abducens nerve palsies. Magnetic resonance imaging of her brain showed typical findings of spontaneous intracranial hypotension. Magnetic resonance imaging of her spine showed an extensive cervicothoracic CSF leak. Computed tomographic myelography showed calcification at the Th1-2 disk space. Three epidural blood patches were performed, but her symptoms persisted. Digital subtraction myelography performed five months later showed an upper thoracic ventral CSF, but the calcification was no longer present. A dural tear, found at surgery at the Th1-2 level, was repaired and the patient made an uneventful recovery. The resorption of calcifications at the level of a ventral spinal CSF leak could explain the absence of any calcifications in at least some patients with such leaks and demonstrates the usefulness of reviewing previous imaging in patients with ventral CSF leaks if the exact site of the leak remains unknown. © International Headache Society 2016.

Endoscopic transpterygoid approach and skull base repair after sphenoid meningoencephalocele resection. Our experience.

PubMed

Martínez Arias, Àngels; Bernal-Sprekelsen, Manuel; Rioja, Elena; Enseñat, Joaquim; Prats-Galino, Alberto; Alobid, Isam

2015-01-01

Cerebrospinal fluid leaks associated to meningoencephaloceles of the sphenoid lateral recess are rare entities. A congenital bony defect at this level results in the persistence of Sternberg's canal, or a lateral craniopharyngeal canal, which is supposed to be the origin of these lesions. Our objective was to show that the endoscopic transpterygoid approach is an effective technique for their treatment. We present a series of 5 cases of meningoencephaloceles of the sphenoid lateral recess treated with endoscopic sinus surgery (4 women and one man; mean age=59, range 37-72 years). Cerebrospinal fluid rhinorrhoea was present in all of them and they all underwent a transpterygoid approach with reconstruction of the skull base. We describe the surgical technique and review the literature. No complications were observed during surgery or the postoperative period. After a mean follow-up of 81 months, only one recurrence was seen. The transpterygoid approach has proven to be effective for the treatment of meningoencephaloceles of the sphenoid lateral recess. Providing wide access to identify the defect, followed by meningoencephalocele ablation, is the key for successful surgery. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Initiation of antiretroviral therapy before detection of colonic infiltration by HIV reduces viral reservoirs, inflammation and immune activation

PubMed Central

Crowell, Trevor A; Fletcher, James LK; Sereti, Irini; Pinyakorn, Suteeraporn; Dewar, Robin; Krebs, Shelly J; Chomchey, Nitiya; Rerknimitr, Rungsun; Schuetz, Alexandra; Michael, Nelson L; Phanuphak, Nittaya; Chomont, Nicolas; Ananworanich, Jintanat

2016-01-01

Introduction Colonic infiltration by HIV occurs soon after infection, establishing a persistent viral reservoir and a barrier to cure. We investigated virologic and immunologic correlates of detectable colonic HIV RNA during acute HIV infection (AHI) and their response to antiretroviral treatment (ART). Methods From 49,458 samples screened for HIV, 74 participants were enrolled during AHI and 41 consented to optional sigmoidoscopy, HIV RNA was categorized as detectable (≥50 copies/mg) or undetectable in homogenized colon biopsy specimens. Biomarkers and HIV burden in blood, colon and cerebrospinal fluid were compared between groups and after 24 weeks of ART. Results Colonic HIV RNA was detectable in 31 participants (76%) and was associated with longer duration since HIV exposure (median 16 vs. 11 days, p=0.02), higher median plasma levels of cytokines and inflammatory markers (CXCL10 476 vs. 148 pg/mL, p=0.02; TNF-RII 1036 vs. 649 pg/mL, p<0.01; neopterin 2405 vs. 1368 pg/mL, p=0.01) and higher levels of CD8+ T cell activation in the blood (human leukocyte antigen - antigen D related (HLA-DR)/CD38 expression 14.4% vs. 7.6%, p <0.01) and colon (8.9% vs. 4.5%, p=0.01). After 24 weeks of ART, participants with baseline detectable colonic HIV RNA demonstrated persistent elevations in total HIV DNA in colonic mucosal mononuclear cells (CMMCs) (median 61 vs. 0 copies/106 CMMCs, p=0.03) and a trend towards higher total HIV DNA in peripheral blood mononuclear cells (PBMC) (41 vs. 1.5 copies/106 PBMCs, p=0.06). There were no persistent differences in immune activation and inflammation. Conclusions The presence of detectable colonic HIV RNA at the time of ART initiation during AHI is associated with higher levels of proviral DNA after 24 weeks of treatment. Seeding of HIV in the gut may have long-lasting effects on the size of persistent viral reservoirs and may represent an important therapeutic target in eradication strategies. PMID:27637172

Whooping cough in school age children presenting with persistent cough in UK primary care after introduction of the preschool pertussis booster vaccination: prospective cohort study.

PubMed

Wang, Kay; Fry, Norman K; Campbell, Helen; Amirthalingam, Gayatri; Harrison, Timothy G; Mant, David; Harnden, Anthony

2014-06-24

To estimate the prevalence and clinical severity of whooping cough (pertussis) in school age children presenting with persistent cough in primary care since the introduction and implementation of the preschool pertussis booster vaccination. Prospective cohort study (November 2010 to December 2012). General practices in Thames Valley, UK. 279 children aged 5 to 15 years who presented in primary care with a persistent cough of two to eight weeks' duration. Exclusion criteria were cough likely to be caused by a serious underlying medical condition, known immunodeficiency or immunocompromise, participation in another clinical research study, and preschool pertussis booster vaccination received less than one year previously. Evidence of recent pertussis infection based on an oral fluid anti-pertussis toxin IgG titre of at least 70 arbitrary units. Cough frequency was measured in six children with laboratory confirmed pertussis. 56 (20%, 95% confidence interval 16% to 25%) children had evidence of recent pertussis infection, including 39 (18%, 13% to 24%) of 215 children who had been fully vaccinated. The risk of pertussis was more than three times higher (21/53; 40%, 26% to 54%) in children who had received the preschool pertussis booster vaccination seven years or more previously than in those who had received it less than seven years previously (20/171; 12%, 7% to 17%). The risk of pertussis was similar between children who received five and three component preschool pertussis booster vaccines (risk ratio for five component vaccine 1.14, 0.64 to 2.03). Four of six children in whom cough frequency was measured coughed more than 400 times in 24 hours. Pertussis can still be found in a fifth of school age children who present in primary care with persistent cough and can cause clinically significant cough in fully vaccinated children. These findings will help to inform consideration of the need for an adolescent pertussis booster vaccination in the United Kingdom. UK Clinical Research Network portfolio ID 8361. © Wang et al 2014.

Whooping cough in school age children presenting with persistent cough in UK primary care after introduction of the preschool pertussis booster vaccination: prospective cohort study

PubMed Central

Fry, Norman K; Campbell, Helen; Amirthalingam, Gayatri; Harrison, Timothy G; Mant, David; Harnden, Anthony

2014-01-01

Objective To estimate the prevalence and clinical severity of whooping cough (pertussis) in school age children presenting with persistent cough in primary care since the introduction and implementation of the preschool pertussis booster vaccination. Design Prospective cohort study (November 2010 to December 2012). Setting General practices in Thames Valley, UK. Participants 279 children aged 5 to 15 years who presented in primary care with a persistent cough of two to eight weeks’ duration. Exclusion criteria were cough likely to be caused by a serious underlying medical condition, known immunodeficiency or immunocompromise, participation in another clinical research study, and preschool pertussis booster vaccination received less than one year previously. Main outcome measures Evidence of recent pertussis infection based on an oral fluid anti-pertussis toxin IgG titre of at least 70 arbitrary units. Cough frequency was measured in six children with laboratory confirmed pertussis. Results 56 (20%, 95% confidence interval 16% to 25%) children had evidence of recent pertussis infection, including 39 (18%, 13% to 24%) of 215 children who had been fully vaccinated. The risk of pertussis was more than three times higher (21/53; 40%, 26% to 54%) in children who had received the preschool pertussis booster vaccination seven years or more previously than in those who had received it less than seven years previously (20/171; 12%, 7% to 17%). The risk of pertussis was similar between children who received five and three component preschool pertussis booster vaccines (risk ratio for five component vaccine 1.14, 0.64 to 2.03). Four of six children in whom cough frequency was measured coughed more than 400 times in 24 hours. Conclusions Pertussis can still be found in a fifth of school age children who present in primary care with persistent cough and can cause clinically significant cough in fully vaccinated children. These findings will help to inform consideration of the need for an adolescent pertussis booster vaccination in the United Kingdom. Study registration UK Clinical Research Network portfolio ID 8361. PMID:24961836

Diagnostic accuracy of PCR in gambiense sleeping sickness diagnosis, staging and post-treatment follow-up: a 2-year longitudinal study.

PubMed

Deborggraeve, Stijn; Lejon, Veerle; Ekangu, Rosine Ali; Mumba Ngoyi, Dieudonné; Pati Pyana, Patient; Ilunga, Médard; Mulunda, Jean Pierre; Büscher, Philippe

2011-02-22

The polymerase chain reaction (PCR) has been proposed for diagnosis, staging and post-treatment follow-up of sleeping sickness but no large-scale clinical evaluations of its diagnostic accuracy have taken place yet. An 18S ribosomal RNA gene targeting PCR was performed on blood and cerebrospinal fluid (CSF) of 360 T. brucei gambiense sleeping sickness patients and on blood of 129 endemic controls from the Democratic Republic of Congo. Sensitivity and specificity (with 95% confidence intervals) of PCR for diagnosis, disease staging and treatment failure over 2 years follow-up post-treatment were determined. Reference standard tests were trypanosome detection for diagnosis and trypanosome detection and/or increased white blood cell concentration in CSF for staging and detection of treatment failure. PCR on blood showed a sensitivity of 88.4% (84.4-92.5%) and a specificity of 99.2% (97.7-100%) for diagnosis, while for disease staging the sensitivity and specificity of PCR on cerebrospinal fluid were 88.4% (84.8-91.9%) and 82.9% (71.2-94.6%), respectively. During follow-up after treatment, PCR on blood had low sensitivity to detect treatment failure. In cerebrospinal fluid, PCR positivity vanished slowly and was observed until the end of the 2 year follow-up in around 20% of successfully treated patients. For T.b. gambiense sleeping sickness diagnosis and staging, PCR performed better than, or similar to, the current parasite detection techniques but it cannot be used for post-treatment follow-up. Continued PCR positivity in one out of five cured patients points to persistence of living or dead parasites or their DNA after successful treatment and may necessitate the revision of some paradigms about the pathophysiology of sleeping sickness.

Pair mobility functions for rigid spheres in concentrated colloidal dispersions: Stresslet and straining motion couplings

NASA Astrophysics Data System (ADS)

Su, Yu; Swan, James W.; Zia, Roseanna N.

2017-03-01

Accurate modeling of particle interactions arising from hydrodynamic, entropic, and other microscopic forces is essential to understanding and predicting particle motion and suspension behavior in complex and biological fluids. The long-range nature of hydrodynamic interactions can be particularly challenging to capture. In dilute dispersions, pair-level interactions are sufficient and can be modeled in detail by analytical relations derived by Jeffrey and Onishi [J. Fluid Mech. 139, 261-290 (1984)] and Jeffrey [Phys. Fluids A 4, 16-29 (1992)]. In more concentrated dispersions, analytical modeling of many-body hydrodynamic interactions quickly becomes intractable, leading to the development of simplified models. These include mean-field approaches that smear out particle-scale structure and essentially assume that long-range hydrodynamic interactions are screened by crowding, as particle mobility decays at high concentrations. Toward the development of an accurate and simplified model for the hydrodynamic interactions in concentrated suspensions, we recently computed a set of effective pair of hydrodynamic functions coupling particle motion to a hydrodynamic force and torque at volume fractions up to 50% utilizing accelerated Stokesian dynamics and a fast stochastic sampling technique [Zia et al., J. Chem. Phys. 143, 224901 (2015)]. We showed that the hydrodynamic mobility in suspensions of colloidal spheres is not screened, and the power law decay of the hydrodynamic functions persists at all concentrations studied. In the present work, we extend these mobility functions to include the couplings of particle motion and straining flow to the hydrodynamic stresslet. The couplings computed in these two articles constitute a set of orthogonal coupling functions that can be utilized to compute equilibrium properties in suspensions at arbitrary concentration and are readily applied to solve many-body hydrodynamic interactions analytically.

Objective assessment of thirst recovery in patients with adipsic diabetes insipidus.

PubMed

Sinha, A; Ball, S; Jenkins, A; Hale, J; Cheetham, T

2011-12-01

Adipsic diabetes insipidus (ADI) is characterised by impaired thirst and defective AVP secretion. We have assessed the thirst response to graded osmotic stimulation using a visual analog scale (VAS) in patients with a history of ADI following surgery for a craniopharyngioma. The patients were thought to be regaining their thirst response but we wanted to confirm that this was the case objectively before relaxing their strict fluid balance regimen. Three patients with adipisa in the presence of hypernatremia following surgery for a craniopharyngioma are described. Their median age at surgery was 13 years (range 11-15 years). All patients had previously demonstrated no desire to drink despite a serum osmolality in excess of 300 mOsmol/kg. Fluid balance was maintained postoperatively with a regimen involving a fixed daily fluid intake and DDAVP dose together with daily weights and regular assessment of capillary sodium concentrations. Patients were thought to be regaining thirst sensation and so were assessed by hypertonic saline infusion (HSI) with thirst measured using a VAS. Patients underwent a HSI test 4, 6 and 9 months post surgery. All had abnormally low AVP production at raised plasma osmolalities but the visual analogue scale confirmed partial or complete thirst recovery. The intensive regimen used to maintain stable serum sodium concentrations was relaxed without the patients subsequently developing a significant hyperosmolar state. We have shown objective recovery of thirst perception in patients with adipsia within 9 months of surgery, despite persistence of cranial diabetes insipidus. These observations indicate that both osmoreceptors regulating thirst and their efferent pathways demonstrate more plasticity than those regulating AVP production. The HSI and thirst VAS are an objective way of assessing patients known to have ADI who are thought to be recovering thirst perception.

Evaluation of Time to Donor Lenticule Apposition Using Intraoperative Optical Coherence Tomography in Descemet Stripping Automated Endothelial Keratoplasty.

PubMed

Titiyal, Jeewan S; Kaur, Manpreet; Falera, Ruchita; Jose, Cijin P; Sharma, Namrata

2016-04-01

To evaluate the time to donor lenticule apposition in cases of Descemet stripping automated endothelial keratoplasty (DSAEK) using microscope-integrated intraoperative optical coherence tomography (iOCT). Thirty eyes of 27 patients planned to undergo Descemet stripping automated endothelial keratoplasty were enrolled in this prospective study. In group I (n = 10), continuous intracameral positive pressure was maintained for 8 minutes. In group II (n = 10) and group III (n = 10), external corneal massage was initiated simultaneously with positive intracameral air pressure. The external corneal massage was continued till complete resolution of interface fluid; the positive intracameral pressure was maintained for 8 minutes in group II and for 5 minutes in group III. The host-donor relationship was continuously monitored with the iOCT. The main outcome measure was time to complete donor lenticule apposition. In group I, the interface fluid persisted after 8 minutes of positive intracameral pressure in all eyes (10/10); hence an external corneal massage was required to achieve optimal donor adherence. In groups II and III, all eyes (20/20) had complete resolution of the interface fluid at the end of 3 minutes. In 100% of the eyes (30/30), the grafts were attached after anterior chamber decompression as seen on the iOCT. In all cases, the donor lenticules were adhered in the postoperative period. iOCT helps in understanding that the donor lenticule is well apposed within 1 to 3 minutes with the technique of simultaneous positive intracameral pressure and external corneal massage. This knowledge minimizes the waiting time for graft apposition and prevents prolonged intraocular pressure elevation.

Suspended sediment dynamics in a large-scale turbidity current: Direct measurements from the deep-water Congo Canyon

NASA Astrophysics Data System (ADS)

Simmons, S.; Azpiroz, M.; Cartigny, M.; Clare, M. A.; Parsons, D. R.; Sumner, E.; Talling, P. J.

2016-12-01

Turbidity currents that transport sediment to the deep ocean deposit a greater volume of sediment than any other process on Earth. To date, only a handful of studies have directly measured turbidity currents, with flow durations ranging from a few minutes to a few hours. Our understanding of turbidity current dynamics is therefore largely derived from scaled laboratory experiments and numerical modelling. Recent years have seen the first field-scale measurements of depth-resolved velocity profiles, but sediment concentration (a key parameter for turbidity currents) remains elusive. Here, we present high resolution measurements of deep-water turbidity currents from the Congo Canyon; one of the world's largest submarine canyons. Direct measurements using acoustic Doppler current profilers (ADCPs) show that flows can last for many days, rather than hours as seen elsewhere, and provide the first quantification of concentration and grain size within deep-water turbidity currents.Velocity and backscatter were measured at 5 second intervals by an ADCP suspended 80 m above the canyon floor, at 2000 m water depth. A novel inversion method using multiple ADCP frequencies enabled quantification of sediment concentration and grain size within the flows. We identify high concentrations of coarse sediment within a thin frontal cell, which outruns a thicker, trailing body. Thus, the flows grow in length while propagating down-canyon. This is distinct from classical models and other field-scale measurements of turbidity currents. The slow-moving body is dominated by suspended fine-grained sediment. The body mixes with the surrounding fluid leaving diffuse clouds of sediment that persist for days after initial entrainment. Ambient tidal flow also controls the mixing within the body and the surrounding fluid. Our results provide a new quantification of suspended sediment within flows and the interaction with the surrounding fluid.

A neurokinin 1 receptor antagonist decreases postoperative peritoneal adhesion formation and increases peritoneal fibrinolytic activity.

PubMed

Reed, Karen L; Fruin, A Brent; Gower, Adam C; Stucchi, Arthur F; Leeman, Susan E; Becker, James M

2004-06-15

Fibrous adhesions remain a major sequela of abdominal surgery. The proinflammatory peptide substance P (SP), known to participate in inflammatory events, may play a key role in adhesion formation. This hypothesis was tested by using an antagonist, CJ-12,255 (Pfizer), that blocks the binding of SP to the neurokinin 1 receptor (NK-1R). Adhesion formation was surgically induced in the peritoneum of rats receiving daily doses of the NK-1R antagonist (NK-1RA; 5.0 or 10.0 mg/kg per day) or saline. On postoperative day 7, both the low and high doses of NK-1RA significantly (P < 0.05) reduced adhesion formation by 45% and 53%, respectively, compared with controls. Subsequently, the effect of NK-1RA administration on peritoneal fibrinolytic activity was investigated to determine a potential mechanism for SP action in the peritoneum. Samples were collected from nonoperated controls and from animals 24 h postsurgery that were administered either NK-1RA or saline. Fibrinolytic activity in peritoneal fluid was assayed by zymography, and expression of tissue plasminogen activator (tPA) and plasminogen activator inhibitor 1, both regulators of fibrinolytic activity, was assessed in peritoneal tissue and fluid by RT-PCR and bioassay, respectively. NK-1RA administration led to a marked (P < 0.05) increase in tPA mRNA levels in peritoneal tissue compared with nonoperated and saline-administered animals. Likewise, NK-1RA administration significantly (P < 0.05) increased tPA in the peritoneal fluid. These data suggest that activation of the NK-1R promotes peritoneal adhesion formation by limiting fibrinolytic activity in the postoperative peritoneum, thus enabling fibrinous adhesions to persist.

Fluid displacement fronts in porous media: pore scale interfacial jumps, pressure bursts and acoustic emissions

NASA Astrophysics Data System (ADS)

Moebius, Franziska; Or, Dani

2014-05-01

The macroscopically smooth and regular motion of fluid fronts in porous media is composed of numerous rapid pore-scale interfacial jumps and pressure bursts that involve intense interfacial energy release in the form of acoustic emissions. The characteristics of these pore scale events affect residual phase entrapment and transport properties behind the front. We present experimental studies using acoustic emission technique (AE), rapid imaging, and liquid pressure measurements to characterize these processes during drainage and imbibition in simple porous media. Imbibition and drainage produce different AE signatures (AE amplitudes obey a power law). For rapid drainage, AE signals persist long after cessation of front motion reflecting fluid redistribution and interfacial relaxation. Imaging revealed that the velocity of interfacial jumps often exceeds front velocity by more than 50 fold and is highly inertial component (Re>1000). Pore invasion volumes reduced deduced from pressure fluctuations waiting times (for constant withdrawal rates) show remarkable agreement with geometrically-deduced pore volumes. Discrepancies between invaded volumes and geometrical pores increase with increasing capillary numbers due to constraints on evacuation opportunity times and simultaneous invasion events. A mechanistic model for interfacial motions in a pore-throat network was developed to investigate interfacial dynamics focusing on the role of inertia. Results suggest that while pore scale dynamics were sensitive to variations in pore geometry and boundary conditions, inertia exerted only a minor effect on phase entrapment. The study on pore scale invasion events paints a complex picture of rapid and inertial motions and provides new insights on mechanisms at displacement fronts that are essential for improved macroscopic description of multiphase flows in porous media.

Incubation relative humidity induces renal morphological and physiological remodeling in the embryo of the chicken (Gallus gallus domesticus).

PubMed

Bolin, Greta; Dubansky, Benjamin; Burggren, Warren W

2017-02-01

The metanephric kidneys of the chicken embryo, along with the chorioallantoic membrane, process water and ions to maintain osmoregulatory homeostasis. We hypothesized that changes in relative humidity (RH) and thus osmotic conditions during embryogenesis would alter the developmental trajectory of embryonic kidney function. White leghorn chicken eggs were incubated at one of 25-30% relative humidity, 55-60% relative humidity, and 85-90% relative humidity. Embryos were sampled at days 10, 12, 14, 16, and 18 to examine embryo and kidney mass, glomerular characteristics, body fluid osmolalities, hematological properties, and whole embryo oxygen consumption. Low and especially high RH elevated mortality, which was reflected in a 10-20% lower embryo mass on D18. Low RH altered several glomerular characteristics by day 18, including increased numbers of glomeruli per kidney, increased glomerular perfusion, and increased total glomerular volume, all indicating potentially increased functional kidney capacity. Hematological variables and plasma and amniotic fluid osmolalities remained within normal physiological values. However, the allantoic, amniotic and cloacal fluids had a significant increase in osmolality at most developmental points sampled. Embryonic oxygen consumption increased relative to control at both low and high relative humidities on Day 18, reflecting the increased metabolic costs of osmotic stress. Major differences in both renal structure and performance associated with changes in incubation humidity occurred after establishment of the metanephric kidney and persisted into late development, and likely into the postnatal period. These data indicate that the avian embryo deserves to be further investigated as a promising model for fetal programming of osmoregulatory function, and renal remodeling during osmotic stress. Copyright © 2016 Elsevier Inc. All rights reserved.

Novel Interpretation of Molecular Diagnosis of Congenital Toxoplasmosis According to Gestational Age at the Time of Maternal Infection

PubMed Central

Sterkers, Yvon; Pratlong, Francine; Albaba, Sahar; Loubersac, Julie; Picot, Marie-Christine; Pretet, Vanessa; Issert, Eric; Boulot, Pierre

2012-01-01

From a prospective cohort of 344 women who seroconverted for toxoplasmosis during pregnancy, 344 amniotic fluid, 264 placenta, and 216 cord blood samples were tested for diagnosis of congenital toxoplasmosis using the same PCR assay. The sensitivity and negative predictive value of the PCR assay using amniotic fluid were 86.3% and 97.2%, respectively, and both specificity and positive predictive value were 100%. Using placenta and cord blood, sensitivities were 79.5% and 21.2%, and specificities were 92% and 100%, respectively. In addition, the calculation of pretest and posttest probabilities and the use of logistic regression allowed us to obtain curves that give a dynamic interpretation of the risk of congenital toxoplasmosis according to gestational age at maternal infection, as represented by the three sample types (amniotic fluid, placenta, and cord blood). Two examples are cited here: for a maternal infection at 25 weeks of amenorrhea, a negative result of prenatal diagnosis allowed estimation of the probability of congenital toxoplasmosis at 5% instead of an a priori (pretest) risk estimate of 33%. For an infection at 10 weeks of amenorrhea associated with a pretest congenital toxoplasmosis risk of 7%, a positive PCR result using placenta at birth yields a risk increase to 43%, while a negative result damps down the risk to 0.02%. Thus, with a molecular diagnosis performing at a high level, and in spite of the persistence of false negatives, posttest risk curves using both negative and positive results prove highly informative, allowing a better assessment of the actual risk of congenital toxoplasmosis and finally an improved decision guide to treatment. PMID:23035201

Ringers lactate vs Normal saline for children with acute diarrhea and severe dehydration- a double blind randomized controlled trial.

PubMed

Mahajan, Vidushi; Sajan, Shiv Saini; Sharma, Amit; Kaur, Jasbinder

2012-12-01

WHO recommends Ringers lactate (RL) and Normal Saline (NS) for rapid intravenous rehydration in childhood diarrhea and severe dehydration. We compared these two fluids for improvement in pH over baseline during rapid intravenous rehydration in children with acute diarrhea. Double-blind randomized controlled trial Pediatric emergency facilities at a tertiary-care referral hospital. Children with acute diarrhea and severe dehydration received either RL (RL-group) or NS (NS-group), 100 mL/kg over three or six hours. Children were reassessed after three or six hours. Rapid rehydration was repeated if severe dehydration persisted. Blood gas was done at baseline and repeated after signs of severe dehydration disappeared. Primary outcome was change in pH from baseline. Secondary outcomes included changes in serum electrolytes, bicarbonate levels, and base-deficit from baseline; mortality, duration of hospital stay, and fluids requirement. Twenty two children, 11 each were randomized to the two study groups. At primary end point (disappearance of signs of severe dehydration), the improvement in pH from baseline was not significant in RL-group [from 7.17 (0.11) to 7.28 (0.09)] as compared to NS-group [7.09 (0.11) to 7.21 (0.09)], P=0.17 (after adjusting for baseline serum Na/ Cl). Among this limited sample size, children in RL group required less fluids [median 310 vs 530 mL/kg, P=0.01] and had shorter median hospital stay [38 vs 51 hours, P=0.03]. There was no difference in improvement in pH over baseline between RL and NS among children with acute diarrhea and severe dehydration.

Microbiology of aquatic environments: Characterizations of the microbiotas of municipal water supplies, the International Space Station Internal Active Thermal Control System's heat transport fluid, and US Space Shuttle drinking water

NASA Astrophysics Data System (ADS)

Bernardini, James Nicholas, III

An understanding of the microbiota within life support systems is essential for the prolonged presence of humans in space. This is because microbes may cause disease or induce biofouling and/or corrosion within spacecraft water systems. It is imperative that we develop effective high-throughput technologies for characterizing microbial populations that can eventually be used in the space environment. This dissertation describes testing and development of such methodologies, targeting both bacteria and viruses in water, and examines the bacterial and viral diversity within two spacecraft life support systems. The bacterial community of the International Space Station Internal Active Thermal Control System (IATCS) was examined using conventional culture-based and advanced molecular techniques including adenosine triphosphate (ATP) and Limulus Amebocyte Lysate (LAL) assays, direct microscopic examination, and analyses of 16S rRNA gene libraries from the community metagenome. The cultivable heterotrophs of the IATCS fluids ranged from below detection limit to 1.1x10 5/100 ml, and viable cells, measured by ATP, ranged from 1.4x10 3/100 ml to 7.7x105/100 ml. DNA extraction, cloning, sequencing, and bioinformatic analysis of the clones from 16S RNA gene libraries showed members of the firmicutes, alpha, beta, and gamma-proteobacteria to be present in the fluids. This persistent microbial bioburden and the presence of probable metal reducers, biofilm formers, and opportunistic pathogens illustrate the need for better characterization of bacterial communities present within spacecraft fluids. A new methodology was developed for detection of viruses in water using microarrays. Samples were concentrated by lyophilization, resuspended and filtered (0.22microm). Viral nucleic acids were then extracted, amplified, fluorescently labeled and hybridized onto a custom microarray with probes for ˜1000 known viruses. Numerous virus signatures were observed. Human Adenovirus C and Influenza A viruses were used to verify positive microarray hybridizations by quantitative polymerase chain reaction (PCR), reverse transcriptase PCR, and conventional PCR. Experiments were performed using municipal drinking water, IATCS fluids, and Shuttle drinking water. Thus, this dissertation describes what we believe is the first molecular analysis of the IATCS bacterial ecology and the first use and validation of a microarray-based assay for the detection of viral genetic signatures within drinking waters.

Seismicity Induced by Groundwater Recharge at Mt. Hood, Oregon, and its Implications for Hydrogeologic Properties.

NASA Astrophysics Data System (ADS)

Saar, M. O.; Manga, M.

2002-12-01

Earthquakes induced by human-caused changes in fluid pressure have been documented for many years. Examples include seismicity induced by filling reservoirs and by fluid injection or extraction. Less well-documented are seismic events that potentially are triggered by natural variations in groundwater recharge rates (e.g., Wolf et al., BSSA, 1997; Jimenez and Garcia-Fernandez, JVGR, 2000; Audin et al., GRL, 2002). Large groundwater recharge rates can occur in Volcanic Arcs such as the Oregon Cascades where annual precipitation is > 2 m of which > 50 % infiltrates the ground mostly during snowmelt in spring. As a result, infiltration rates of > 1 m per year concentrated during a few months can occur. Near-surface porosities are about 5-10 %. Thus, groundwater levels may fluctuate annually by about 10-20 m resulting in seasonal pore fluid pressure variations of about 1-2 x 105 Pa. Such large-amplitude, narrow-duration fluid pressure signals may allow investigation of seismicity induced by pore fluid pressure diffusion without the influence of engineered systems such as reservoirs. This kind of in-situ study of natural systems over large representative elementary volumes may allow determination of hydrologic parameters at spatial and temporal scales that are relevant for regional hydrogeology. Furthermore, natural hydrologic triggering of earthquakes that persist for decades provides insight into the state of stress in the crust and suggest long-term near-critical failure conditions. Here, we approximate the temporal variations in groundwater recharge with discharge in runoff-dominated streams at high elevations that show a peak in discharge during snow melt. Seismicity is evaluated as time series of daily number of earthquakes and seismic moments. Both stream discharge and seismicity are compared at equivalent frequency bands by applying segmented least-squares polynomial fits to the data. We find statistically significant correlation between groundwater recharge and seismicity at Mt. Hood, Oregon. We can use the time lag of about 120 days between the two records to estimate the regional hydraulic diffusivity (1 m2/s) and other hydrogeologic parameters (permeability ≈ 10-13 m2, vertical matrix compressibility ≈ 10-10 m2/N). These values are comparable with our results from coupled heat and groundwater flow studies that are based on bore hole temperature data at Mt. Hood.

Multidisciplinary assessment of post-Ebola sequelae in Guinea (Postebogui): an observational cohort study.

PubMed

Etard, Jean-François; Sow, Mamadou Saliou; Leroy, Sandrine; Touré, Abdoulaye; Taverne, Bernard; Keita, Alpha Kabinet; Msellati, Philippe; Magassouba, N'Fally; Baize, Sylvain; Raoul, Hervé; Izard, Suzanne; Kpamou, Cécé; March, Laura; Savane, Ibrahima; Barry, Moumié; Delaporte, Eric

2017-05-01

The high number of survivors from the 2013-16 west African outbreak of Ebola virus disease (EVD) has raised several new issues: long-term clinical complications, psychosocial consequences, risks of EVD reactivation, and secondary transmission due to viral persistence in body fluids. We aimed to assess long-term clinical, psychosocial, and viral outcomes in EVD survivors in Guinea. In this multidisciplinary observational cohort study, we recruited patients aged 1 year or more in four sites in Guinea (Donka National Hospital, Conakry; Macenta Prefectoral Hospital, Macenta; N'zérékoré Regional Hospital, N'zérékoré; and Forécariah Prefectoral Hospital, Forécariah) following discharge from any Ebola treatment centre in Guinea. Eligible patients had had laboratory-confirmed EVD and had then been declared clear of the virus in the blood. All consenting patients were included, with no exclusion criteria. Trained clinicians assessed patients at enrolment to the cohort, recording clinical symptoms and signs of depression. We did routine blood examinations and examined viral persistence in body fluids using RT-PCR. We did psychological evaluations using questionnaires developed for different age groups. Follow-up is planned to 2 years, and here we present findings at enrolment. Between March 23, 2015, and July 11, 2016, we recruited 802 patients, of whom 360 (45%) were male, 442 (55%) were female; 158 (20%) were younger than 18 years. The median age was 28·4 years (range 1·0-79·9, IQR 19·4-39·8). The median delay after discharge was 350 days (IQR 223-491). The most frequent symptoms were general symptoms (324 [40%] patients), musculoskeletal pain (303 [38%]), headache (278 [35%]), depression (124 [17%] of 713 responses), abdominal pain (178 [22%]), and ocular disorders (142 [18%]). More adults than children had at least one clinical symptom (505 [78%] vs 101 [64%], p<0·0003), ocular complications (124 [19%] vs 18 [11%], p=0·0200), or musculoskeletal symptoms (274 [43%] vs 29 [18%], p<0·0001). A positive RT-PCR in semen was found in ten (5%) of 188 men, at a maximum of 548 days after disease onset. 204 (26%) of 793 patients reported stigmatisation. Ocular complications were more frequent at enrolment than at discharge (142 [18%] vs 61 [8%] patients). Post-EVD symptoms can remain long after recovery and long-term viral persistence in semen is confirmed. The results justify calls for regular check-ups of survivors at least 18 months after recovery. INSERM/Reacting, the French Ebola Task Force, and Institut de Recherche pour le Développement. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does the "sleeping Dragon" Really Sleep?: the Case for Continuous Long-Term Monitoring at a Gulf of Mexico Cold Seep Site

NASA Astrophysics Data System (ADS)

Wilson, R. M.; Lapham, L.; Farr, N.; Lutken, C.; MacDonald, I. R.; Macelloni, L.; Riedel, M.; Sleeper, K.; Chanton, J.

2011-12-01

Continuous porewater monitoring indicates that the methane flux away from exposed hydrate mounds can vary considerably over time. Recently, we retrieved a Pore Fluid Array instrument pack from a hydrate outcrop adjacent to a NEPTUNE Canada observatory node. The sampler was designed to continuously collect and store sediment pore fluids over the course of 9 months. On analysis, we observed a 35mM variation in methane concentrations corresponding with an abrupt shift in current direction at the site. Video and resistivity data have led to previous speculation that hydrate growth and dissolution/dissociation may be seasonally variable. Cumulatively, these findings suggest that the persistence of hydrate outcrops may be extremely dynamic, driven by fluctuations in physical conditions on short time scales. Short-term monitoring in the Gulf of Mexico within Mississippi Canyon lease block 118 (MC118), a known hydrate-bearing site, indicates that physical conditions even at these depths (~540-890m) may be highly variable. Pressure can vary within hours, and recorded temperature changes of ~1.5°C have been associated with passing storms. Moreover, increased particle abundance was observed at the site in 2007 suggesting that organic matter flux to the sediments may vary on the scale of months to years. These inputs have the potential to alter the chemical environment surrounding the hydrate, thereby affecting dissolution rates. Continuous, long-term observations of physical conditions at MC118 could provide information about the potential for natural perturbations to impact hydrate dynamics on the scale of weeks or even days necessary for assessing the long-term persistence of hydrate outcrops. Sleeping Dragon is a massive hydrate outcrop at MC118 that has been monitored since 2006. Three years ago, researchers returning to the site found it visibly diminished relative to previous observations. This apparent shift toward net dissolution of the mound may have been precipitated by changes in physical and chemical conditions at the site. We propose that the dynamics of hydrate stability may be compared to an oscillating "see-saw" where fluctuations in physical conditions tip the balance alternately in favor of dissociation/dissolution or hydrate growth. The chemical environment at MC118 results from the interaction among physical parameters, fluid/particle flux, and biological processes occurring near the hydrate surface. Given that these parameters may be varying on the scale of days, weeks, months, and possibly even years, long-term continuous monitoring will play a key role in understanding the stability conditions at MC118 and the potential for gas release from this methane reservoir should the dragon be awakened.

Communicating Risks Associated with Onshore Oil and Gas Development: A Reflective Case Study from a Public Health Perspective

NASA Astrophysics Data System (ADS)

Blake, U.

2017-12-01

The growth of onshore oil and natural gas development (OGD) over the past decade has led to an increase in environmental health concerns caused by potential risks associated with industry activities. While the industry has shown commitment to protecting the environment and the health and safety of all who share it (through the development of standards and best practices, and the support of relevant research projects), the negative rhetoric persists. The persistence can be related to differences in the perception of risks, complicated by the uncertainties associated with published and unpublished scientific findings, which are experienced and communicated differently by scientists, regulators, industry and the public. For example, to industry operators, hydraulic fracturing is a "well completion" operation, during which fracturing fluid is pumped down a well to the target formation, under high pressure (pressure high enough to exceed the formation fracture gradient). However, to the general public, the term hydraulic fracturing represents the entire onshore exploration and production operation (from pad development to the production of the resource). This difference in language is the tip of the iceberg that represents the challenges industry faces when communicating its operations to the public. By reflecting on industry experiences, this presentation offers a reflective case study that relates the challenges of navigating and communicating within a narrative of purported health effects, to risk perception and communication theories.

A RESCUE THERAPY FOR PERSISTENT OPTIC DISK PIT MACULOPATHY IN PREVIOUSLY VITRECTOMIZED EYES.

PubMed

Figueroa, Marta S; Nadal, Jeroni; Contreras, Inés

2018-01-01

To report the results of vitrectomy with platelet-rich plasma (PRP) application and gas tamponade as a rescue therapy in previously vitrectomized eyes with optic disk pit (ODP) maculopathy. Three patients with visual loss due to persistent or recurrent ODP maculopathy who had undergone previous vitrectomy were offered application of PRP. Platelet-rich plasma was obtained by centrifugation of a blood sample from each patient. Surgery consisted of vitrectomy and internal limiting membrane peeling if the membrane had not been already removed (in two eyes). After fluid/air exchange, three drops of PRP were applied on the ODP followed by 8% C3F8 tamponade. Immediately after surgery, the patient remained supine for 30 minutes and then kept a face-down position for 2 weeks. Optic disk pit maculopathy improved as soon as two weeks after surgery and resolved in all eyes between six and eight months after PRP application. Patients were followed up for three years, with no recurrences. Visual acuity remained stable in one eye and improved in two eyes. Vitrectomy with PRP application may be useful as a rescue therapy in patients with refractory ODP maculopathy. Platelet-rich plasma may act by promoting the closure of the communication between the vitreous and the intraretinal/subretinal space at the pit. This treatment may avoid potentially harmful maneuvers that have been used to treat ODP maculopathy.

[Tuberculous pyopneumothorax: about 18 cases].

PubMed

Hicham, Souhi; Hanane, El Ouazzani; Hicham, Janah; Ismaïl, Rhorfi; Ahmed, Abid

2016-01-01

Tuberculous pyopneumothorax is a rare but serious complication of evolutive pulmonary tuberculosis. We report a series of 18 cases with tuberculous pyopneumothorax admitted to the Pneumo-Phthisiology Department of the Mohammed V Military Teaching Hospital in Rabat between January 2005 and December 2009. Our study included 15 men and 3 women, the average age was 35 ± 7 years. 4 patients were diabetic. Smoking was found in 9 cases. Right-sided pneumothorax was found in 13 cases. Chest radiograph showed cavitary lesions in 15 patients and extensive bilateral lesions in 8 cases. The search for Mycobacterium tuberculosis in the fluid from the gastric tube was positive in 16 cases. Chest drainage associated with antituberculosis treatment according to the 2SRHZ/7RH regimen and respiratory kinesitherapy were performed in all cases. The average duration of pleural drainage was 4 weeks. In 3 cases we noted persistent pleural suppuration requiring pleural toilet using thoracoscopy with pleurectomy and limited pulmonary resection to eliminate tuberculous parenchymal lesions and the persistence of a large pleural pocket with restrictive ventilatory defect that required surgery for pleural decortication in two cases. The outcome was favorable with minimal pachypleuritis as sequelae in the remaining cases. Tuberculous pyopneumothorax is a severe form, which is often associated with active cavitary tuberculosis. Evolution is generally progressive despite antituberculosis treatment and thoracic drainage, hence the need for early diagnosis and treatment of all forms of tuberculosis.

Environmentally persistent free radicals induce airway hyperresponsiveness in neonatal rat lungs

PubMed Central

2011-01-01

Background Increased asthma risk/exacerbation in children and infants is associated with exposure to elevated levels of ultrafine particulate matter (PM). The presence of a newly realized class of pollutants, environmentally persistent free radicals (EPFRs), in PM from combustion sources suggests a potentially unrecognized risk factor for the development and/or exacerbation of asthma. Methods Neonatal rats (7-days of age) were exposed to EPFR-containing combustion generated ultrafine particles (CGUFP), non-EPFR containing CGUFP, or air for 20 minutes per day for one week. Pulmonary function was assessed in exposed rats and age matched controls. Lavage fluid was isolated and assayed for cellularity and cytokines and in vivo indicators of oxidative stress. Pulmonary histopathology and characterization of differential protein expression in lung homogenates was also performed. Results Neonates exposed to EPFR-containing CGUFP developed significant pulmonary inflammation, and airway hyperreactivity. This correlated with increased levels of oxidative stress in the lungs. Using differential two-dimensional electrophoresis, we identified 16 differentially expressed proteins between control and CGUFP exposed groups. In the rats exposed to EPFR-containing CGUFP; peroxiredoxin-6, cofilin1, and annexin A8 were upregulated. Conclusions Exposure of neonates to EPFR-containing CGUFP induced pulmonary oxidative stress and lung dysfunction. This correlated with alterations in the expression of various proteins associated with the response to oxidative stress and the regulation of glucocorticoid receptor translocation in T lymphocytes. PMID:21388553

Secretory IgA as an indicator of oro-pharyngeal foot-and-mouth disease virus replication and as a tool for post vaccination surveillance.

PubMed

Parida, Satya; Anderson, John; Cox, Sarah J; Barnett, Paul V; Paton, David J

2006-02-20

A serotype-specific ELISA was developed to detect foot-and-mouth disease virus (FMDV) specific IgA antibody in the saliva of cattle, and the method was evaluated for its feasibility in detecting serotype O FMDV carrier animals, particularly amongst vaccinated cattle that had subsequently become sub-clinically infected. For this purpose, saliva samples were collected from naïve cattle (n = 173), FMDV challenged cattle (n = 10), FMDV vaccinated cattle (n = 40) and FMDV vaccinated-and-challenged cattle (n = 40). A subset of 29 cattle was sampled for 105-168 days after challenge. The FMDV infection status of each of the cattle was determined by virus isolation and RT-PCR tests on oesophago-pharyngeal fluids and the ability of the IgA test to detect viral infection and persistence was compared to an ELISA for the detection of serum antibodies against the 3ABC non-structural proteins of FMDV. Eleven out of twelve vaccinated cattle that were shown to be persistently infected with FMDV up to or beyond 28 days post challenge, were also detected by the IgA test on saliva. With some modification and further validation, this test could be useful in post-vaccination surveillance to help confirm the absence of sub-clinical infection in order to regain the FMD-free status of a region or country.

Observations and simulations of the bottom nepheloid layer in the Lafourche Trough, Louisiana Continental Shelf

NASA Astrophysics Data System (ADS)

Jolliff, J.; Jarosz, E.; Penko, A.; Smith, T.

2017-12-01

The "Lafourche Trough" is a mud/silt -dominated, elongate seafloor depression located between transgressive sandy shoals approximately 50 km south of Cocodrie, Louisiana. These irregular bathymetric features are relicts of the abandoned Lafourche delta complex that still have an impact upon coupled sediment-hydrodynamic processes occurring today. Repeated optical and physical oceanographic surveys conducted during the spring of 2015 and winter 2017 reveal persistent bottom nepheloid layers (BNLs) characterized by extreme optical turbidity (beam attenuation 10 m-1, 532 nm). The manifestation and persistence of cohesive sediment BNLs in this area appears to result from a complex interplay between tidal currents, bathymetry, and frontal dynamics along the edge of the Mississippi River plume. Numerical experiments were performed using the Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS), an integrated air-sea-wave operational forecasting tool, that includes a simplified numerical sediment resuspension and transport scheme in order to simulate the nepheloid layer observations through the trough. The model results suggest that the wave-current bottom boundary layer is a critical factor in BNL development, and thusly, without wave model integration into COAMPS the system struggles to replicate the observations. Future modeling work will need to explore the potential suppression of physical mixing due to density perturbations along the BNL to fluid mud continuum within the bottom boundary layer.

Theories of otitis media pathogenesis, with a focus on Indigenous children.

PubMed

Wiertsema, Selma P; Leach, Amanda J

2009-11-02

Otitis media is a common childhood illness associated with hearing loss, social disadvantage and medical costs. Prevalence and severity are high among Indigenous children. Respiratory bacterial and viral pathogens ascend the eustachian tube from the nasopharynx to the middle ear, causing inflammation, fluid accumulation, and bulging of the tympanic membrane, with or without pain. Among Australian Indigenous children, ear disease commences earlier in life, and involves multiple strains of bacterial pathogens at high density that persist longer. Persistent nasal discharge, overcrowded living conditions (particularly exposure to many children) and poor facilities for washing children perpetuate a vicious cycle of transmission and infection. Risk factors include environmental tobacco smoke, season, lack of breastfeeding, younger age and immature immune system, and possibly genetic factors. The innate immune system is a critical first response to infection, particularly as passive maternal antibodies decline and during the maturation of the infant adaptive immune response. The relative contributions of innate factors to protection from otitis media are currently not well understood. A diversity of antibodies that target strain-specific and conserved antigens are generated in response to natural exposure to otitis media pathogens (or to vaccines). Deficiencies in these antibodies may explain susceptibility to recurrent infections. Incremental contributions from all these elements are likely to be important in otitis media susceptibility versus protection. Effective medical and social strategies to prevent early age of onset are urgently needed.

Pressure in an exactly solvable model of active fluid

NASA Astrophysics Data System (ADS)

Marini Bettolo Marconi, Umberto; Maggi, Claudio; Paoluzzi, Matteo

2017-07-01

We consider the pressure in the steady-state regime of three stochastic models characterized by self-propulsion and persistent motion and widely employed to describe the behavior of active particles, namely, the Active Brownian particle (ABP) model, the Gaussian colored noise (GCN) model, and the unified colored noise approximation (UCNA) model. Whereas in the limit of short but finite persistence time, the pressure in the UCNA model can be obtained by different methods which have an analog in equilibrium systems, in the remaining two models only the virial route is, in general, possible. According to this method, notwithstanding each model obeys its own specific microscopic law of evolution, the pressure displays a certain universal behavior. For generic interparticle and confining potentials, we derive a formula which establishes a correspondence between the GCN and the UCNA pressures. In order to provide explicit formulas and examples, we specialize the discussion to the case of an assembly of elastic dumbbells confined to a parabolic well. By employing the UCNA we find that, for this model, the pressure determined by the thermodynamic method coincides with the pressures obtained by the virial and mechanical methods. The three methods when applied to the GCN give a pressure identical to that obtained via the UCNA. Finally, we find that the ABP virial pressure exactly agrees with the UCNA and GCN results.

Hemorrhoids and fistulas: new solutions to old problems.

PubMed

Rakinic, Jan; Poola, Venkateswara Prasad

2014-03-01

Symptoms thought related to hemorrhoids must be carefully considered before intervention. The first line of therapy for any hemorrhoidal complaint remains conservative management with increased fluid and fiber intake and appropriate modification of toileting behavior. Bleeding in grades 1 and 2 hemorrhoids that does not respond to this can be satisfactorily and safely managed with office-based therapies; some grade 3 hemorrhoids would also respond to this, though more treatment sessions would likely be required. Operative therapy is the best choice for management of persistently symptomatic grade 2 disease and for grades 3 and 4 symptomatic hemorrhoids as well. With proper patient selection and preparation, along with a familiarity with instrumentation and techniques, good results can be obtained with newer operative interventions for internal hemorrhoids. Outcomes must always be compared with those obtained with classic excisional hemorrhoidectomy.

Purulent pericarditis with Salmonella enteritidis in a patient with CD4/CD8 depression.

PubMed

Takamiya, Yosuke; Shirai, Kazuyuki; Fujino, Masahiro; Miller, Nathan; Tsuchiya, Yoshihiro; Okabe, Masanori; Saku, Keijiro

2008-06-01

A 65-year-old man was admitted for high-grade fever with a shaking chill and general fatigue. Chest X-ray showed cardiomegaly, and echocardiography revealed a large amount of pericardial effusion. Emergency pericardiocentesis was performed, and Salmonella enteritidis was found in pericardial fluids. We diagnosed purulent pericarditis with S. enteritidis, and administered antibiotics. While high-grade fever resolved 10 days after beginning of treatment, effusive-constrictive pericarditis (ECP) without definite symptoms persisted for 2 months. Because of the improvement of his hemodynamic states on cardiac catheterization after 1 year, an operative procedure was not required. He was diagnosed as having CD4/CD8 depression without apparent diseases. There are few reports of pericarditis with S. enteritidis, and we believe this case might be only the second recorded case of ECP with S. enteritidis.

CONCEPTUAL MODEL FOR ORIGIN OF ABNORMALLY PRESSURED GAS ACCUMULATIONS IN LOW-PERMEABILITY RESERVOIRS.

USGS Publications Warehouse

Law, B.E.; Dickinson, W.W.

1985-01-01

The paper suggests that overpressured and underpressured gas accumulations of this type have a common origin. In basins containing overpressured gas accumulations, rates of thermogenic gas accumulation exceed gas loss, causing fluid (gas) pressure to rise above the regional hydrostatic pressure. Free water in the larger pores is forced out of the gas generation zone into overlying and updip, normally pressured, water-bearing rocks. While other diagenetic processes continue, a pore network with very low permeability develops. As a result, gas accumulates in these low-permeability reservoirs at rates higher than it is lost. In basins containing underpressured gas accumulations, rates of gas generation and accumulation are less than gas loss. The basin-center gas accumulation persists, but because of changes in the basin dynamics, the overpressured accumulation evolves into an underpressured system.

Perforated mesenteric Meckel's diverticulum in an adult: a real variant?

PubMed Central

Gueye, M.L.; Thiam, O.; Seck, M.; Gueye, M.N.; Toure, A.O.; Cisse, M.; Ka, O.; Dieng, M.; Toure, C.T.

2015-01-01

A Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract. It is a real diverticulum that is usually located on the anti-mesenteric edge in the last meter of the ileum. Its location on the mesenteric edge has been rarely reported. It may lead to several complications including perforation that may be life-threatening for the patient. We report herein a case of perforated mesenteric Meckel's diverticulum in an adult patient. Upon surgical exploration by laparotomy, we found a perforated Meckel's diverticulum located on the mesenteric edge of the ileum 60 cm from the ileocoecal junction and 400 ml of seropurulent peritoneal fluid. The patient underwent a segmental ileal resection and an end-to-end anastomosis. The postoperative outcomes were marked by a persistent peritonitis that required successful revision surgery. PMID:26330235

Optical and physical requirements for fluid particles marking trailing vortices from aircraft

NASA Technical Reports Server (NTRS)

Back, L. H.

1976-01-01

A theoretical study of the optical and physical requirements of marking trailing vortices that emanate from aircraft wings was carried out by considering particulate light-scattering properties, ability of particles to follow trailing vortices, and survival time of particles to vortex dissipation. Liquid droplets undergoing evaporation and molecular dispersion were investigated. Droplets should have lifetimes of about 300 sec. Droplet size should be about 1 micron to maximize light scattering with the minimum mass of liquid required. Droplets of this small size would spiral outward very slowly and essentially remain in the vortex cores. Nontoxic hygroscopic liquids, having an affinity for moisture in the air, have been identified. These liquids have relatively low vapor pressures of order 10 to the -5 mm Hg that would insure droplet persistence long enough to mark trailing vortices.

The lunar dynamo

NASA Astrophysics Data System (ADS)

Weiss, Benjamin P.; Tikoo, Sonia M.

2014-12-01

The inductive generation of magnetic fields in fluid planetary interiors is known as the dynamo process. Although the Moon today has no global magnetic field, it has been known since the Apollo era that the lunar rocks and crust are magnetized. Until recently, it was unclear whether this magnetization was the product of a core dynamo or fields generated externally to the Moon. New laboratory and spacecraft measurements strongly indicate that much of this magnetization is the product of an ancient core dynamo. The dynamo field persisted from at least 4.25 to 3.56 billion years ago (Ga), with an intensity reaching that of the present Earth. The field then declined by at least an order of magnitude by ∼3.3 Ga. The mechanisms for sustaining such an intense and long-lived dynamo are uncertain but may include mechanical stirring by the mantle and core crystallization.

Temporal chaos in Boussinesq magnetoconvection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bekki, Naoaki; Moriguchi, Hirofumi; Fundamental Science, Gifu National College of Technology, Motosu, Gifu 501-0495

2007-01-15

Two-dimensional Boussinesq magnetoconvection with idealized stress-free boundary conditions is numerically investigated in order to make clear the difference between chaos and turbulence. It is shown that the long-term behavior of magnetoconvection exhibits spatially coherent and temporally chaotic rolls in marked contrast to highly turbulent fluids. It is also shown that heat transport becomes larger anomalously when the polarity reversal of the magnetic field occurs intermittently in the case of temporally chaotic magnetoconvection. It is found that the Poincare return map of the relative maximum temperature fluctuation of partial differential equations as a function of the preceding maximum resembles the famousmore » Lorenz plot in narrow rolls of magnetoconvection. The chaotic behavior of narrow rolls for individual parameter values robustly persists up to rolls about one fifth as wide as they are high near the codimension-two bifurcation point.« less

[Assessment and treatment of acute pancreatitis. Position document of the Catalan Society of Gastroenterology, Catalan Society of Surgery and Catalan Society of the Pancreas].

PubMed

Boadas, Jaume; Balsells, Joaquin; Busquets, Juli; Codina-B, Antoni; Darnell, Anna; Garcia-Borobia, Francisco; Ginés, Àngels; Gornals, Joan; Gruartmoner, Guillem; Ilzarbe, Lucas; Merino, Xavier; Oms, Lluís; Puig, Ignasi; Puig-Diví, Valentí; Vaquero, Eva; Vida, Francesc; Molero, Xavier

2015-02-01

The incidence of acute pancreatitis (AP) is increasing. AP is one of the gastrointestinal diseases that most frequently requires hospital admission in affected individuals. In the last few years, considerable scientific evidence has led to substantial changes in the medical and surgical treatment of this disease. New knowledge of the physiopathology of AP indicates that its severity is influenced by its systemic effects (organ failure), especially if the disease is persistent, and also by local complications (fluid collections or necrosis), especially if these become infected. Treatment should be personalized and depends on the patient's clinical status, the location of the necrosis, and disease stage. Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

[Fatal toxic leukoencephalopathy associated with consumption of pasta base of cocaine: Report of three cases].

PubMed

Cartier R, Luis; González L, Daniela; Harán D, Jorge

2015-11-01

The prevalence of drug-associated toxic encephalopathy is unknown, but it is an uncommon condition. Toxic leukoencephalopathy was described associated with heroin consumption, it has been less commonly described with the use of cocaine and there are no reports of its association with consumption pasta base of cocaine (PBC). We report two females aged 31 years and a male aged 19 years, consumers of PBC who developed a fatal toxic leukoencephalopathy. They initiated their disease with severe and persistent headache, sequential focal neurologic deficits and a progressive impairment of consciousness that culminated with their death. Laboratory parameters such as blood count, cerebrospinal fluid analyses or infectious biological indices were normal. MRI showed multifocal lesions in brain white matter of both hemispheres confirming the leukoencephalopathy. There was no response to the use of methylprednisolone.

Stochastic transitions and jamming in granular pipe flow

NASA Astrophysics Data System (ADS)

Brand, Samuel; Ball, Robin C.; Nicodemi, Mario

2011-03-01

We study a model granular suspension driven down a channel by an embedding fluid via computer simulations. We characterize the different system flow regimes and the stochastic nature of the transitions between them. For packing fractions below a threshold ϕm, granular flow is disordered and exhibits an Ostwald-de Waele-type power-law shear-stress constitutive relation. Above ϕm, two asymptotic states exist; disordered flow can persist indefinitely, yet, in a fraction of samples, the system self-organizes in an ordered form of flow where grains move in parallel ordered layers. In the latter regime, the Ostwald-de Waele relationship breaks down and a nearly solid plug appears in the center, with linear shear regions at the boundaries. Above a higher threshold ϕg, an abrupt jamming transition is observed if ordering is avoided.

Rickettsial meningitis.

PubMed

Salva, Inês; de Sousa, Rita; Gouveia, Catarina

2014-03-10

Rickettsial infections are common in southern Europe and the most frequent and lethal type is Mediterranean spotted fever, caused by Rickettsia conorii. The disease is usually characterised by the classical triad of fever, eschar and rash, and is generally a mild disease in children. Complications including neurological involvement are rarely described. We report an unusual case of meningitis in an 18-year-old man, presenting during summer with fever and persistent headache. The cerebrospinal fluid analysis revealed increased cellularity (107 cells/μL), hypoglycorrhachia (50% of glycaemia) and hyperproteinorrhachia (284 mg/dL). Rickettsial infection was confirmed by serology and the patient was treated with doxycycline, with a favourable outcome. The patient's pet squirrel and/or associated vectors might be involved in the transmission of Rickettsia spp. This case underlines the importance of a high clinical suspicion and the benefits of early empirical treatment when facing compatible epidemiological contexts.

Localization and Instability in Sheared Granular Materials: Role of Pore Fluids and Non-monotonic Rate Dependent Rheology

NASA Astrophysics Data System (ADS)

Ma, X.; Elbanna, A. E.; Kothari, K.

2017-12-01

Fault zone dynamics hold the key to resolving many outstanding geophysical problems including the heat flow paradox, discrepancy between fault static and dynamic strength, and energy partitioning. Most fault zones that generate tectonic events are gouge filled and fluid saturated posing the need for formulating gouge-specific constitutive models that capture spatially heterogeneous compaction and dilation, non-monotonic rate dependence, and transition between localized and distributed deformation. In this presentation, we focus primarily on elucidating microscopic underpinnings for shear banding and stick-slip instabilities in sheared saturated granular materials and explore their implications for earthquake dynamics. We use a non-equilibrium thermodynamics model, the Shear Transformation Zone theory, to investigate the dynamics of strain localization and its connection to stability of sliding in the presence and absence of pore fluids. We also consider the possible influence of self-induced mechanical vibrations as well as the role of external acoustic vibrations as analogue for triggering by a distant event. For the dry case, our results suggest that at low and intermediate strain rates, persistent shear bands develop only in the absence of vibrations. Vibrations tend to fluidize the granular network and de-localize slip at these rates. Stick-slip is only observed for rough grains and it is confined to the shear band. At high strain rates, stick-slip disappears and the different systems exhibit similar stress-slip response. Changing the vibration intensity, duration or time of application alters the system response and may cause long-lasting rheological changes. The presence of pore fluids modifies the stick slip pattern and may lead to both loss and development of slip instability depending on the value of the confining pressure, imposed strain rate and hydraulic parameters. We analyze these observations in terms of possible transitions between rate strengthening and rate weakening response facilitated by a competition between shear induced dilation and acoustic compaction. We discuss the implications of our results on dynamic triggering, quiescence and strength evolution in gouge filled fault zones.

Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

PubMed Central

Hartmann, Albrecht; Hannemann, Franziska; Lützner, Jörg; Seidler, Andreas; Drexler, Hans; Günther, Klaus-Peter; Schmitt, Jochen

2013-01-01

Introduction The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. Objective To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Methods Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Results Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Discussion Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip resurfacing arthroplasty. Patients with implanted MoM-bearing should receive regular and standardized monitoring of metal ion concentrations. Further research is indicated especially with regard to potential systemic reactions due to accumulation of metal products. PMID:23950923

Understanding How Space Travel Affects Blood Vessels: Arterial Remodeling and Functional Adaptations Induced by Microgravity

NASA Technical Reports Server (NTRS)

Delp, Michael; Vasques, Marilyn; Aquilina, Rudy (Technical Monitor)

2002-01-01

Ever rise quickly from the couch to get something from the kitchen and suddenly feel dizzy? With a low heart rate and relaxed muscles, the cardiovascular system does not immediately provide the resistance necessary to keep enough blood going to your head. Gravity wins, at least for a short time, before your heart and blood vessels can respond to the sudden change in position and correct the situation. Actually, the human cardiovascular system is quite well adapted to the constant gravitational force of the Earth. When standing, vessels in the legs constrict to prevent blood from collecting in the lower extremities. In the space environment, the usual head-to-foot blood pressure and tissue fluid gradients that exist during the upright posture on Earth are removed. The subsequent shift in fluids from the lower to the upper portions of the body triggers adaptations within the cardiovascular system to accommodate the new pressure and fluid gradients. In animal models that simulate microgravity, the vessels in the head become more robust while those in the lower limbs become thin and lax. Similar changes may also occur in humans during spaceflight and while these adaptations are appropriate for a microgravity environment, they can cause problems when the astronauts return to Earth or perhaps another planet. Astronauts often develop orthostatic intolerance which means they become dizzy or faint when standing upright. This dizziness can persist for a number of days making routine activities difficult. In an effort to understand the physiological details of these cardiovascular adaptations, Dr. Michael Delp at Texas A&M University, uses the rat as a model for his studies. For the experiment flown on STS-107, he will test the hypothesis that blood vessels in the rats' hindlimbs become thinner, weaker, and constrict less in response to pressure changes and to chemical signals when exposed to microgravity. In addition, he will test the hypothesis that arteries in the brain become thicker as a result of microgravity-induced fluid shifts toward the head.

Numerical simulation of a slit resonator in a grazing flow under acoustic excitation

NASA Astrophysics Data System (ADS)

Tam, Christopher K. W.; Ju, Hongbin; Walker, Bruce E.

2008-06-01

It is known experimentally that a grazing flow has significant influence on the performance of a resonant acoustic liner. As yet, detailed understanding of the effect in fluid dynamics or acoustics terms is not available. One principal reason for this is the small size of the openings of the resonators of present day jet engine acoustic liners. The small size of the holes makes in-depth experimental observation and mapping of the fluid flow field around the opening of a resonator in the presence of a grazing flow extremely difficult. As a result, there is a genuine lack of data leading directly to a lack of understanding. The face sheet of an acoustic liner is entirely covered with holes (the openings of resonators underneath). There is, therefore, a possibility of fluid mechanical interaction between neighboring resonators. However, evidence for such interaction is not available at this time. One of the objectives of the present work is to shed light on whether this is possible and what is a possible interaction mechanism. In this study, numerical simulations of the flow field around a slit resonator in the presence of a grazing flow under acoustic forcing are carried out. It is observed that at high sound pressure level, vortices are shed from the corners of the resonator opening. Some of these vortices merge together. Others are absorbed by the wall boundary layer or dissipated by viscosity. The simulated results indicate that a strong merged vortex is convected downstream by the grazing flow and persists for a long distance. This suggests that possible fluid mechanical interaction between neighboring resonators of an acoustic liner could, indeed, be possible because of the interference of this convected vortex with the flow field of the downstream resonator. This interaction, as far as is known, has not been included in any theoretical or semi-empirical model of acoustic liners. Detailed formulation of the computational model, as well as computational algorithm, is provided. The computation code is verified by comparing computed results with an exact linear solution and also validated by comparing with measurements of a companion experiment.