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Sample records for intracranial ring enhancing

  1. Intracranial hypertension as the primary symptom of gastric signet-ring cell carcinoma

    PubMed Central

    Pu, Jiali; Xu, Lingjia; Yin, Xinzhen; Zhang, Baorong

    2016-01-01

    Abstract Background: Intracranial hypertension (IH) is a neurological disorder characterized by increased intracranial pressure. It is a poorly understood syndrome that most commonly manifests nonspecific symptoms such as stroke-like headache, vision changes, nausea, vomiting, and papilledema. IH has been reported in young cancer patients but never in association with gastric signet-ring cell carcinoma. Methods: Here, we discuss the case of an 18-year-old girl with gastric signet-ring cell carcinoma in which IH was the primary symptom accompanied by the even rarer symptom of cutaneous metastases. We also present a review of the relevant literature. The patient experienced frequent headaches, vomiting, and blurred vision but showed no abnormal findings on cranial imaging studies. Further examination showed multiple skin nodules on the abdomen. Then pathological and immunohistochemical examination of gastroscopic specimens and the biopsied subcutaneous nodules were done. Results: Pathological and immunohistochemical examination of gastroscopic specimens and the biopsied subcutaneous nodules confirmed gastric signet-ring cell carcinoma with skin metastases. Conclusion: To our knowledge, this is the first reported case of gastric signet-ring cell carcinoma primarily presenting IH and accompanied by subcutaneous metastases. This case emphasizes the importance of excluding malignancy from the differential diagnosis of IH. PMID:27583897

  2. Contrast-enhancing computed tomography ring in glioblastoma multiforme after intraoperative endocurietherapy

    SciTech Connect

    Kumar, P.P.; Good, R.R.; Jones, E.O.; Skultety, F.M.; Leibrock, L.G.; McComb, R.D.

    1988-05-01

    The significance of the contrast-enhancing ring seen on serial follow-up postirradiation computed tomograms (CT) of the brain was evaluated in a group of 41 patients with glioblastoma multiforme (GM) who were treated in a phase I/II study by means of intraoperative remote afterloading endocurietherapy (ECT) with a high activity cobalt 60 probe (20.00 Gy) in one high-dose rate fraction), and conventional fractionated external-beam (EXRT) radiotherapy (60.00 Gy in 30 fractions in 7.5 weeks). All received minimum total tumor doses of 80.00 Gy. After completion of treatment, all patients were followed with serial CT scans of the brain. Two to 6 months after treatment, 27 of 41 patients developed the similar thin-walled, regular, contrast-enhancing CT rings with low-density attenuation inside and outside the ring. Postmortem study in two of these patients revealed that the thin-walled, regular, contrast-enhancing ring represented a continuous capsule of dilated cerebral vessels with inner low-density attenuation corresponding to necrosis, and outer low-density attenuation corresponding to edema. The CT appearance of the thin-walled, regular, contrast-enhancing ring produced after high-dose rate intraoperative ECT and EXRT is distinctly different from the CT ring characteristic of untreated or recurrent GM. After high-dose rate intracranial ECT and EXRT, the appearance of a post-ECT contrast-enhancing CT ring should not be automatically interpreted as recurrent disease as previously reported after conventional fractionated EXRT.

  3. Importance of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Various Intracranial Pathologic Conditions

    PubMed Central

    Lee, Eun Kyoung; Kim, Sungwon; Lee, Yong Seok

    2016-01-01

    Intracranial lesions may show contrast enhancement through various mechanisms that are closely associated with the disease process. The preferred magnetic resonance sequence in contrast imaging is T1-weighted imaging (T1WI) at most institutions. However, lesion enhancement is occasionally inconspicuous on T1WI. Although fluid-attenuated inversion recovery (FLAIR) sequences are commonly considered as T2-weighted imaging with dark cerebrospinal fluid, they also show mild T1-weighted contrast, which is responsible for the contrast enhancement. For several years, FLAIR imaging has been successfully incorporated as a routine sequence at our institution for contrast-enhanced (CE) brain imaging in detecting various intracranial diseases. In this pictorial essay, we describe and illustrate the diagnostic importance of CE-FLAIR imaging in various intracranial pathologic conditions. PMID:26798225

  4. p53 Small Molecule Inhibitor Enhances Temozolomide Cytotoxic Activity against Intracranial Glioblastoma Xenografts

    PubMed Central

    Dinca, Eduard B.; Lu, Kan V.; Sarkaria, Jann N.; Pieper, Russell O.; Prados, Michael D.; Haas-Kogan, Daphne A.; VandenBerg, Scott R.; Berger, Mitchel S.; James, C. David

    2010-01-01

    In this study we investigated corresponding precursor and active forms of a p53 small molecule inhibitor for effect on temozolomide (TMZ) anti-tumor activity against glioblastoma (GBM), using both in vitro and in vivo experimental approaches. Results from in vitro cell viability analysis showed that the cytotoxic activity of TMZ was substantially increased when GBMs with wild-type p53 were co-treated with the active form of p53 inhibitor, and this heightened cytotoxic response was accompanied by increased PARP cleavage as well as elevated cellular phospho-H2AX. Analysis of the same series of GBMs, as intracranial xenografts in athymic mice, and administering corresponding p53 inhibitor precursor, that is converted to the active compound in vivo, yielded results consistent with the in vitro analyses: i.e., TMZ + p53 inhibitor precursor co-treatment, of three distinct wild-type p53 GBM xenografts, resulted in significant enhancement of TMZ anti-tumor effect relative to treatment with TMZ alone, as indicated by serial bioluminescence monitoring as well as survival analysis (p < 0.001 for co-treatment survival benefit in each case). Mice receiving intracranial injection with p53 null GBM showed similar survival benefit from TMZ treatment regardless of the presence or absence of p53 inhibitor precursor. In total, our results indicate that the p53 active and precursor inhibitor pair enhance TMZ cytotoxicity in vitro and in vivo, respectively, and do so in a p53-dependent manner. PMID:19074867

  5. p53 Small-molecule inhibitor enhances temozolomide cytotoxic activity against intracranial glioblastoma xenografts.

    PubMed

    Dinca, Eduard B; Lu, Kan V; Sarkaria, Jann N; Pieper, Russell O; Prados, Michael D; Haas-Kogan, Daphne A; Vandenberg, Scott R; Berger, Mitchel S; James, C David

    2008-12-15

    In this study, we investigated the precursor and active forms of a p53 small-molecule inhibitor for their effects on temozolomide (TMZ) antitumor activity against glioblastoma (GBM), using both in vitro and in vivo experimental approaches. Results from in vitro cell viability analysis showed that the cytotoxic activity of TMZ was substantially increased when p53 wild-type (p53(wt)) GBMs were cotreated with the active form of p53 inhibitor, and this heightened cytotoxic response was accompanied by increased poly(ADP-ribose) polymerase cleavage as well as elevated cellular phospho-H2AX. Analysis of the same series of GBMs, as intracranial xenografts in athymic mice, and administering corresponding p53 inhibitor precursor, which is converted to the active compound in vivo, yielded results consistent with the in vitro analyses: TMZ + p53 inhibitor precursor cotreatment of three distinct p53(wt) GBM xenografts resulted in significant enhancement of TMZ antitumor effect relative to treatment with TMZ alone, as indicated by serial bioluminescence monitoring as well as survival analysis (P < 0.001 for cotreatment survival benefit in each case). Mice receiving intracranial injection with p53(null) GBM showed similar survival benefit from TMZ treatment regardless of the presence or absence of p53 inhibitor precursor. In total, our results indicate that the p53 active and precursor inhibitor pair enhances TMZ cytotoxicity in vitro and in vivo, respectively, and do so in a p53-dependent manner.

  6. Imaging of the intracranial venous system with a contrast-enhanced volumetric interpolated examination.

    PubMed

    Wetzel, Stephan G; Law, Meng; Lee, Vivian S; Cha, Soonmee; Johnson, Glyn; Nelson, Kim

    2003-05-01

    A contrast-enhanced interpolated, three-dimensional (3D) gradient-echo MR sequence with asymmetric k-space sampling, which we refer to as volumetric interpolated brain examination (VIBE), was evaluated for its depiction of the normal intracranial venous system and compared with two-dimensional (2D) time-of-flight (TOF) MR venography (MRV). Fifteen subjects underwent contrast-enhanced VIBE imaging (TR/TE 8 ms/4.4 ms, flip angle 18 degrees, acquisition time, 2 min 20 s, voxel size approximately 1.5 mm(3)) and standard 2D TOF MRV (TR/TE 27 ms/9 ms, flip angle 35 degrees ). The presence of 19 venous structures per subject was assessed on maximum intensity projections (MIP) of the whole data set (whole-brain MIP) and on MIP images reconstructed spontaneously from source images (interactive MIP/source images). Results from a consensus reading where all imaging techniques and display modalities were available were taken as the standard of reference for the presence of venous structures. In addition, 10 subjects underwent both unenhanced and enhanced VIBE imaging. The value of subtracted data sets (unenhanced VIBE subtracted from enhanced VIBE) was then evaluated. Overall, VIBE provided a superior visualization of the cerebral veins than 2D TOF MRV (VIBE, sensitivity (reader 1/reader 2): 98%/99%, negative predictive value 64%/71%; TOF sensitivity: 85%/84%, negative predictive value 15%/15%; Wilcoxon signed-rank test VIBE vs TOF, p<0.001 for both readers). The VIBE interactive MIP/source images were superior to whole-brain MIP reconstructions. Image subtraction was not necessary for delineation of venous structures but improved small vein conspicuity. Contrast-enhanced VIBE acquisitions are faster and enable a visualization of the normal intracranial venous system superior to that of 2D TOF MRV.

  7. Drag-Reducing Polymer Enhances Microvascular Perfusion in the Traumatized Brain with Intracranial Hypertension.

    PubMed

    Bragin, Denis E; Thomson, Susan; Bragina, Olga; Statom, Gloria; Kameneva, Marina V; Nemoto, Edwin M

    2016-01-01

    Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood-soluble, nontoxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and ischemic limb, but have not yet been studied in the brain. We recently demonstrated that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using in vivo two-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow, and, as a result, reduced tissue hypoxia in both nontraumatized and traumatized rat brains at high intracranial pressure. Our study suggests that DRP could constitute an effective treatment for improving microvascular flow in brain ischemia caused by high intracranial pressure after TBI. PMID:27165871

  8. Drag-Reducing Polymer Enhances Microvascular Perfusion in the Traumatized Brain with Intracranial Hypertension.

    PubMed

    Bragin, Denis E; Thomson, Susan; Bragina, Olga; Statom, Gloria; Kameneva, Marina V; Nemoto, Edwin M

    2016-01-01

    Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood-soluble, nontoxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and ischemic limb, but have not yet been studied in the brain. We recently demonstrated that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using in vivo two-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow, and, as a result, reduced tissue hypoxia in both nontraumatized and traumatized rat brains at high intracranial pressure. Our study suggests that DRP could constitute an effective treatment for improving microvascular flow in brain ischemia caused by high intracranial pressure after TBI.

  9. Medial temporal theta/alpha power enhancement precedes successful memory encoding: evidence based on intracranial EEG.

    PubMed

    Fell, Juergen; Ludowig, Eva; Staresina, Bernhard P; Wagner, Tobias; Kranz, Thorsten; Elger, Christian E; Axmacher, Nikolai

    2011-04-01

    Not only poststimulus, but also prestimulus neural activity has been shown to be predictive for later successful memory encoding. However, it is still not clear which medial temporal lobe processes precede effective memory formation. Here, our aim was to investigate whether such prestimulus markers for successful memory encoding can be specified based on intracranial recordings directly from the hippocampus and rhinal cortex. For this purpose, we analyzed subsequent memory effects during a continuous word recognition paradigm in 31 presurgical epilepsy patients. We found that rhinal and hippocampal theta and successive alpha power enhancement before word presentation predicted successful memory encoding. Previous studies suggest that stimulus-triggered hippocampal theta activity is particularly related to memory retrieval and activation of a mnemonic context, whereas the alpha rhythm reflects inhibitory top-down control of task processing and executive functioning. In line with these suggestions, we propose that the observed medial temporal theta and alpha power increases before stimulus presentation reflect activation of contextual information and inhibitory top-down control processes preparing for stimulus-triggered memory processing.

  10. Loop 2 of Ophiophagus hannah toxin b binds with neuronal nicotinic acetylcholine receptors and enhances intracranial drug delivery.

    PubMed

    Zhan, Changyou; Yan, Zhiqiang; Xie, Cao; Lu, Weiyue

    2010-12-01

    Three-finger snake neurotoxins have been widely investigated for their high binding affinities with nicotinic acetylcholine receptors (nAChRs), which are widely expressed in the central nervous system including the blood-brain barrier and thus mediate intracranial drug delivery. The loop 2 segments of three-finger snake neurotoxins are considered as the binding domain with nAChRs, and thus, they may have the potential to enhance drug or drug delivery system intracranial transport. In the present work, binding of the synthetic peptides to the neuronal nAChRs was assessed by measuring their ability to inhibit the binding of (125)I-α-bungarotoxin to the receptor. The loop 2 segment of Ophiophagus hannah toxin b (KC2S) showed high binding affinity, and the competitive binding IC(50) value was 32.51 nM. Furthermore, the brain targeting efficiency of KC2S had been investigated in vitro and in vivo. The specific uptake by brain capillary endothelial cells (BCECs) demonstrated that KC2S could be endocytosized after binding with nAChRs. In vivo, the qualitative and quantitative biodistribution results of fluorescent dyes (DiR or coumarin-6) indicated that KC2S modified poly(ethylene glycol)-poly(lactic acid) micelles (KC2S-PEG-PLA micelles) could enhance intracranial drug delivery. Furthermore, intravenous treatment with paclitaxel-encapsulated KC2S-PEG-PLA micelles (KC2S-PEG-PLA-PTX micelles) afforded robust inhibition of intracranial glioblastoma. The median survival time of KC2S-PEG-PLA-PTX-micelle-treated mice (47.5 days) was significantly longer than that of mice treated by mPEG-PLA-PTX micelles (41.5 days), Taxol (38.5 days), or saline (34 days). Compared with the short peptide derived from rabies virus glycoprotein (RVG29) that has been previously reported as an excellent brain targeting ligand, KC2S has a similar binding affinity with neuronal nAChRs but fewer amino acid residues. Thus, we concluded that the loop 2 segment of Ophiophagus hannah toxin b could bind

  11. Extramedullary hematopoietic lesion of the orbit presenting as a ring enhancing lesion.

    PubMed

    Crum, Alison V; Morris, Heather; Hogan, R Nick; Mancini, Ronald

    2013-01-01

    A 47-year-old healthy man presented with symptoms of double vision and drooping of the right upper eyelid. Examination disclosed signs of vertical diplopia and right upper-eyelid ptosis. An MRI delineated a well circumscribed, ring enhancing mass within the right orbit. The mass with peripheral enhancement located within the orbit, generated a broad differential diagnosis. After an excisional biopsy was performed, the mass was revealed to be fibrosis with extramedullary hematopoiesis. Current differential diagnoses of ring enhancing orbital lesions do not include extramedullary hematopoiesis, but we present a unique presentation of extramedullary hematopoiesis presenting as a ring enhancing orbital mass.

  12. Multiple ring-enhancing lesions: diagnostic dilemma between neurocysticercosis and tuberculoma.

    PubMed

    Verma, Rajesh; Gupta, Rahul

    2014-04-07

    Multiple ring-enhancing lesions in the brain often raise many questions about the true diagnosis. The aetiologies are many neoplastic, infectious, vascular, inflammatory and demyelinating conditions and also depend on the geographical location of the patient. The two important causes of multiple ring-enhancing lesions in the cranium are multiple neurocysticercosis and multiple tuberculomas in developing countries like India. This case report illustrates how multiple ring-enhancing lesions cause a diagnostic dilemma between neurocysticercosis and tuberculoma. A young girl with a typical presentation of neurocysticercosis finally turned out to be a case of tuberculoma. A high index of suspicion is required in appropriate clinical settings to have best clinical outcome.

  13. Super defect inside photonic crystal ring resonator to enhance Q factor

    NASA Astrophysics Data System (ADS)

    Sreenivasulu, Tupakula; Kolli, Venkateswara Rao; Tarimala, Badrinarayana; Hegde, Gopalkrishna; Sangineni, Mohan; Talabattula, Srinivas

    2016-03-01

    A design is proposed to enhance the quality factor of a photonic crystal ring resonator. A super defect is employed inside the ring resonator, which consists of variation of hole dimensions inside the ring resonator in such a way that the radiation field components of the resonant nanocavity are forced to get cancelled in order to reduce radiation loss. After this forced cancellation, the improved Q factor is calculated as 18,000. This photonic crystal ring resonator can be used for sensing applications like force sensing, pressure sensing, biochemical sensing, and communication applications like demultiplexing.

  14. Enhanced ring lasers: a new measurement tool for Earth sciences

    NASA Astrophysics Data System (ADS)

    Schreiber, K. U.; Kluegel, T.; Wells, J.-P.; Holdaway, J.; Gebauer, A.; Velikoseltsev, A.

    2012-11-01

    We report the progress in the technology of fabrication of large ring lasers that has resulted in an increase in instrumental rotation sensitivity by as much as a factor of 3, to δΩ = 1.2 × 10-11 rad s-1 Hz-1/2, which makes the domain of changes in the angular velocity of Earth's rotation, ΔΩ/Ω ≈ 10-9, accessible to a local rotation sensor. New studies show that the largest contribution to the observed deviation in sensor performance with respect to the computed shot noise limit is caused by the micro-seismic background activity of the Earth. Our efforts have been concentrated on the improvement of sensor stability, including correction of drift effects, which are caused by the aging of the laser gas, fixing scale factor instabilities induced by atmospheric pressure variations, and minimising the temperature variations resulting from corresponding adiabatic expansion and compression of the local air around the instrument. To achieve this, we have recently introduced a pressure-stabilising vessel with dimensions slightly larger than the ring laser apparatus, such that it encloses the entire structure. By monitoring the optical frequency in the ring laser cavity continuously and stabilising the scale factor in a closed loop system with the pressure-stabilising vessel, it has become possible to extend the range of sensor stability from the short term (1 — 3 days) to well into the mid-term regime (>40 days), and possibly even well beyond that. Once a sufficiently long timeseries of the ring laser data has been recorded, we will be able to define the range of temporal stability in more detail. The extension of the regime of stability gives access to geophysical signals at frequencies substantially lower than previously observable with ring lasers.

  15. Enhanced ring lasers: a new measurement tool for Earth sciences

    SciTech Connect

    Schreiber, K U; Kluegel, T; Wells, J.-P.; Holdaway, J; Gebauer, A; Velikoseltsev, A

    2012-11-30

    We report the progress in the technology of fabrication of large ring lasers that has resulted in an increase in instrumental rotation sensitivity by as much as a factor of 3, to {delta}{Omega} = 1.2 Multiplication-Sign 10{sup -11} rad s{sup -1} Hz{sup -1/2}, which makes the domain of changes in the angular velocity of Earth's rotation, {Delta}{Omega}/{Omega} Almost-Equal-To 10{sup -9}, accessible to a local rotation sensor. New studies show that the largest contribution to the observed deviation in sensor performance with respect to the computed shot noise limit is caused by the micro-seismic background activity of the Earth. Our efforts have been concentrated on the improvement of sensor stability, including correction of drift effects, which are caused by the aging of the laser gas, fixing scale factor instabilities induced by atmospheric pressure variations, and minimising the temperature variations resulting from corresponding adiabatic expansion and compression of the local air around the instrument. To achieve this, we have recently introduced a pressure-stabilising vessel with dimensions slightly larger than the ring laser apparatus, such that it encloses the entire structure. By monitoring the optical frequency in the ring laser cavity continuously and stabilising the scale factor in a closed loop system with the pressure-stabilising vessel, it has become possible to extend the range of sensor stability from the short term (1 - 3 days) to well into the mid-term regime (>40 days), and possibly even well beyond that. Once a sufficiently long timeseries of the ring laser data has been recorded, we will be able to define the range of temporal stability in more detail. The extension of the regime of stability gives access to geophysical signals at frequencies substantially lower than previously observable with ring lasers. (laser applications and other topics in quantum electronics)

  16. Intracranial imaging.

    PubMed Central

    Gibson, M.; Cook, G.; Al-Kutoubi, A.

    1996-01-01

    This article concentrates on the imaging of intracranial structures and outlines some basic imaging strategies for common clinical presentations. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 PMID:8935596

  17. Resonance Raman enhancement of phenyl ring vibrational modes in phenyl iron complex of myoglobin.

    PubMed

    Liu, H H; Lin, S H; Yu, N T

    1990-04-01

    Resonance Raman spectra are reported for the organometallic phenyl-FeIII complexes of horse heart myoglobin. We observed the resonance enhancement of the ring vibrational modes of the bound phenyl group. They were identified at 642, 996, 1,009, and 1,048 cm-1, which shift to 619, 961, 972, and 1,030 cm-1, respectively, upon phenyl 13C substitution. The lines at 642 and 996 cm-1 are assigned, respectively, as in-plane phenyl ring deformation mode (derived from benzene vibration No. 6a at 606 cm-1) and out-of-plane CH deformation (derived from benzene vibration No. 5 at 995 cm-1). The frequencies of the ring "breathing" modes at 1,009 and 1,048 cm-1 are higher than the corresponding ones in phenylalanine (at 1,004 and 1,033 cm-1) and benzene (at 992 and 1,010 cm-1), indicating that the ring C--C bonds are strengthened (or shortened) when coordinated to the heme iron. The excitation profiles of these phenyl ring modes and a porphyrin ring vibrational mode at 674 cm-1 exhibit peaks near its Soret absorption maximum at 431 nm. This appears to indicate that these phenyl ring modes may be enhanced via resonance with the Soret pi-pi transition. The FeIII--C bond stretching vibration has not been detected with excitation wavelengths in the 406.7-457.9-nm region.

  18. Optical Peaking Enhancement in High-Speed Ring Modulators

    PubMed Central

    Müller, J.; Merget, F.; Azadeh, S. Sharif; Hauck, J.; García, S. Romero; Shen, B.; Witzens, J.

    2014-01-01

    Ring resonator modulators (RRM) combine extreme compactness, low power consumption and wavelength division multiplexing functionality, making them a frontrunner for addressing the scalability requirements of short distance optical links. To extend data rates beyond the classically assumed bandwidth capability, we derive and experimentally verify closed form equations of the electro-optic response and asymmetric side band generation resulting from inherent transient time dynamics and leverage these to significantly improve device performance. An equivalent circuit description with a commonly used peaking amplifier model allows straightforward assessment of the effect on existing communication system architectures. A small signal analytical expression of peaking in the electro-optic response of RRMs is derived and used to extend the electro-optic bandwidth of the device above 40 GHz as well as to open eye diagrams penalized by intersymbol interference at 32, 40 and 44 Gbps. Predicted peaking and asymmetric side band generation are in excellent agreement with experiments. PMID:25209255

  19. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances

    PubMed Central

    Zhou, Yong Jin; Xiao, Qian Xun; Jia Yang, Bao

    2015-01-01

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform. PMID:26420668

  20. Thermo-optical tuning of cascaded double micro-ring resonators for dynamic range enhancement

    NASA Astrophysics Data System (ADS)

    Prasad, Prashanth R.; Selvaraja, Shankar K.; Varma, Manoj M.

    2016-03-01

    We report on a silicon-photonic cascaded microring sensor with thermo-optic tuning for extension of detection range. Cascaded microring resonators have been used to realize refractive index sensors with high sensitivity in the intensity detection mode. In this configuration, one ring is used to probe analyte while the other ring (called filter) is used for spectrum overlap measurement. A significant drawback of this configuration is decreased range of detection. We overcome this problem by thermo-optically tuning the spectrum the filter ring to track the position of maximum overlap, as the spectrum of the probing ring undergoes shift. Using this peak tracking method, we have experimentally demonstrated range enhancement by a factor of 7.8, compared to the intensity detection scheme. This method can use a broadband source for operation, and has a potential for development of low cost, point of care biomedical applications.

  1. Vessel-selective, non-contrast enhanced, time-resolved MR angiography with vessel-selective arterial spin labeling technique (CINEMA-SELECT) in intracranial arteries.

    PubMed

    Nakamura, Masanobu; Yoneyama, Masami; Tabuchi, Takashi; Takemura, Atsushi; Obara, Makoto; Tatsuno, Satoshi; Sawano, Seishi

    2013-07-01

    We demonstrate the feasibility of the vessel-selective, non-contrast, time-resolved magnetic resonance angiography (MRA) technique, "contrast inherent inflow enhanced multi-phase angiography combining vessel-selective arterial spin labeling technique (CINEMA-SELECT)". This sequence consists of two major techniques: pulsed star labeling of arterial regions (PULSAR) and Look-Locker sampling. We hypothesize that this technique allows selective labeling of single intracranial arteries, consisting of high-resolution four-dimensional data with a wide coverage of the brain. In this study, a new vessel-selective, time-resolved angiographic technique is demonstrated that can produce individual angiograms non-invasively by labeling the principal arterial vessels proximal to the circle of Willis. Clear vessel delineation is achieved, and the separation of the three vessels is evident in healthy volunteers. This technique could play an important role in the assessment of the structure and hemodynamics of intracranial arteries without the use of contrast agents. PMID:23475783

  2. Intracranial pseudoaneurysm after intracranial pressure monitor placement.

    PubMed

    Shah, Kushal J; Jones, Aaron M; Arnold, Paul M; Ebersole, Koji

    2014-12-12

    Traumatic intracranial pseudoaneurysms are a rare but severe complication following arterial injury. Pseudoaneurysm formation can occur secondary to blunt or penetrating trauma or iatrogenic injury. We report a case of traumatic pseudoaneurysm secondary to placement of an intracranial pressure (ICP) monitor. A 27-year-old man was involved in a motorcycle accident resulting in multiple intracranial hemorrhages. The patient underwent craniectomy and placement of an ICP monitor. 17 days later he developed dilation of his left pupil, with imaging demonstrating a new hemorrhage in the vicinity of the previous ICP monitor. A cerebral angiogram confirmed a left-sided distal M4 pseudoaneurysm which was treated by n-butyl cyanoacrylate embolization. Intracranial pseudoaneurysm formation following neurosurgical procedures is uncommon. Delayed intracranial hemorrhage in a region of prior intracranial manipulation, even following a procedure as 'routine' as placement of an ICP monitor, should raise the suspicion for this rare but potentially lethal complication.

  3. Sensitivity enhancement for evanescent-wave sensing using cavity-ring-down ellipsometry.

    PubMed

    Sofikitis, Dimitris; Stamataki, Katerina; Everest, Michael A; Papadakis, Vassilis; Stehle, Jean-Louis; Loppinet, Benoit; Rakitzis, T Peter

    2013-04-15

    We demonstrate a method to increase the sensitivity of the s-p phase shift under total internal reflection (TIR) for optical sensing. This is achieved by the introduction of two simple dielectric layers to the TIR surface of a fused silica prism. The enhanced sensitivity is demonstrated using evanescent-wave cavity-ring-down-ellipsometry by measuring the refractive index of liquid mixtures and by studying the adsorption of polymers to the TIR surface of the fused silica prism.

  4. Surface-plasmon-enhanced photoluminescence of quantum dots based on open-ring nanostructure array

    NASA Astrophysics Data System (ADS)

    Kannegulla, Akash; Liu, Ye; Cheng, Li-Jing

    2016-03-01

    Enhanced photoluminescence (PL) of quantum dots (QD) in visible range using plasmonic nanostructures has potential to advance several photonic applications. The enhancement effect is, however, limited by the light coupling efficiency to the nanostructures. Here we demonstrate experimentally a new open-ring nanostructure (ORN) array 100 nm engraved into a 200 nm thick silver thin film to maximize light absorption and, hence, PL enhancement at a broadband spectral range. The structure is different from the traditional isolated or through-hole split-ring structures. Theoretical calculations based on FDTD method show that the absorption peak wavelength can be adjusted by their period and dimension. A broadband absorption of about 60% was measured at the peak wavelength of 550 nm. The emission spectrum of CdSe/ZnS core-shell quantum dots was chosen to match the absorption band of the ORN array to enhance its PL. The engraved silver ORN array was fabricated on a silver thin film deposited on a silicon substrate using focus ion beam (FIB) patterning. The device was characterized by using a thin layer of QD water dispersion formed between the ORN substrate and a cover glass. The experimental results show the enhanced PL for the QD with emission spectrum overlapping the absorption band of ORN substrate and quantum efficiency increases from 50% to 70%. The ORN silver substrate with high absorption over a broadband spectrum enables the PL enhancement and will benefit applications in biosensing, wavelength tunable filters, and imaging.

  5. Open-ring enhancement in pseudotumoral multiple sclerosis: important radiological aspect.

    PubMed

    de Medeiros, Frederico Carvalho; de Albuquerque, Lucas Alverne Freitas; Pittella, Jose Eymard Homem; de Souza, Renata Brant; Gomes Neto, Antonio Pereira; Christo, Paulo Pereira

    2014-01-01

    Introduction. Observation of open-ring enhancement in magnetic resonance imaging (MRI) is considered a specificity marker for diagnosing pseudotumoral multiple sclerosis (MS). This finding is of great value in the differential diagnosis of tumefactive lesions. Case Report. We describe a 55-year-old white woman, with previous history of ovarian cancer and recent history of fatigue and bilateral retroorbital pain. Important bilateral visual impairment evolved over one month. Physical examination detected the presence of right homonymous hemianopia. Cranial MRI showed an expanding lesion with open-ring enhancement. Given the range of diagnostic possibilities, a stereotactic biopsy was performed, and histopathological examination was consistent with an active demyelinating disease. The patient was treated with 1 g of methylprednisolone and symptoms improved following a significant reduction in the lesion. Conclusions. We highlight the MRI results suggestive of pseudotumoral MS, especially open-ring enhancement, which is an important radiologic aspect to diagnosis and can assist in avoiding unnecessary biopsies. PMID:24839572

  6. OPUS – Outer Planets Unified Search with Enhanced Surface Geometry Parameters – Not Just for Rings

    NASA Astrophysics Data System (ADS)

    Gordon, Mitchell; Showalter, Mark Robert; Ballard, Lisa; Tiscareno, Matthew S.; Heather, Neil

    2016-10-01

    In recent years, with the massive influx of data into the PDS from a wide array of missions and instruments, finding the precise data you need has been an ongoing challenge. For remote sensing data obtained from Jupiter to Pluto, that challenge is being addressed by the Outer Planets Unified Search, more commonly known as OPUS.OPUS is a powerful search tool available at the PDS Ring-Moon Systems Node (RMS) – formerly the PDS Rings Node. While OPUS was originally designed with ring data in mind, its capabilities have been extended to include all of the targets within an instrument's field of view. OPUS provides preview images of search results, and produces a zip file for easy download of selected products, including a table of user specified metadata. For Cassini ISS and Voyager ISS we have generated and include calibrated versions of every image.Currently OPUS supports data returned by Cassini ISS, UVIS, VIMS, and CIRS (Saturn data through June 2010), New Horizons Jupiter LORRI, Galileo SSI, Voyager ISS and IRIS, and Hubble (ACS, WFC3 and WFPC2).At the RMS Node, we have developed and incorporated into OPUS detailed geometric metadata, based on the most recent SPICE kernels, for all of the bodies in the Cassini Saturn observations. This extensive set of geometric metadata is unique to the RMS Node and enables search constraints such as latitudes and longitudes (Saturn, Titan, and icy satellites), viewing and illumination geometry (phase, incidence and emission angles), and distances and resolution.Our near term plans include adding the full set of Cassini CIRS Saturn data (with enhanced geometry), New Horizons MVIC Jupiter encounter images, New Horizons LORRI and MVIC Pluto data, HST STIS observations, and Cassini and Voyager ring occultations. We also plan to develop enhanced geometric metadata for the New Horizons LORRI and MVIC instruments for both the Jupiter and the Pluto encounters.OPUS: http://pds-rings.seti.org/search/

  7. On-chip tunable dispersion in a ring laser gyroscope for enhanced rotation sensing

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Liu, Jiaming; Lin, Jian; Li, Wenxiu; Xue, Xia; Huang, Anping; Xiao, Zhisong

    2016-05-01

    A gyroscope structure with tailored local dispersion profile to enhance sensitivity is proposed, which uses lithium niobate (LiNbO3) thin film as the on-chip material of gyroscope's resonator. A Mach-Zehnder interferometer (MZI) structure as a coupler, which induces a different reference phase shift in each arm, is inserted into the position between ring resonator and output bus waveguide. Through modulating reference phase shift in MZI, theoretical rotation sensitivity enhancement as large as one order of magnitude is presented.

  8. Enhanced light emission from Ge quantum dots in photonic crystal ring resonator.

    PubMed

    Zhang, Yong; Zeng, Cheng; Li, Danping; Zhao, Xiangjie; Gao, Ge; Yu, Jinzhong; Xia, Jinsong

    2014-05-19

    Light emitter based on Ge quantum dots embedded in photonic crystal ring resonator is designed and fabricated. Six sharp resonant peaks dominate the photoluminescence (PL) spectrum ranging from 1500 to 1600 nm at room temperature. The light emission enhancement is due to Purcell effect and high collection efficiency of the PCRR verified by calculated far-field patterns. The Purcell factor of the PCRR is estimated from enhancement factor and increased collection efficiency. The linewidth of the emission of a single Ge quantum dot is estimated from the Purcell factor. PMID:24921343

  9. Intracranial Vascular Treatments

    MedlinePlus

    ... most commonly used in the treatment of intracranial aneurysms. Mechanical retrievers/aspiration systems: used to remove clots ... passageway between an artery and a vein. intracranial aneurysms, a ballooning out of the wall of an ...

  10. Interference enhancement and modulation introduced by surface plasmon polaritons in a concentric-ring structure

    NASA Astrophysics Data System (ADS)

    Lai, Senfeng; Wu, Wen; Peng, Li; Gu, Wenhua

    2015-10-01

    This article studied the interference enhancement and modulation introduced by surface plasmon polaritons (SPPs) in a double-concentric-ring structure. Young's double-slit interference experiment is a classic experiment in the history of physics, and has many modifications with deep impacts in many areas including physics, optics, and electromagnetics. In this work, to use the classic bull's eye structure to produce the surface plasmon polariton effect, a double-concentricring- hole structure was used instead of the double-slit structure to generate optical interference, and the bull's eye structure was applied in the surroundings to generate surface plasmonic wave for modulation of the interference. For structure details, a concentric double-ring-hole was etched in a silver film, with a series of periodic concentric-ringshaped shallow grooves etched in both the upper and bottom surfaces of the silver films. Simulation results showed that the interference of the double-ring-hole could be modulated by SPPs, generating new transmission spectra with desired peak positions and intensities. The transmission peak intensity could be enhanced by 2 to 6 times. The proposed structure can be used as a powerful and convenient tool to adjust the transmission spectra, which can have promising applications in the design and implementation of optical devices for filtering and sensing, especially in the sub-wavelength structure size range.

  11. Maximizing slow-light enhancement in one-dimensional photonic crystal ring resonators.

    PubMed

    McGarvey-Lechable, Kathleen; Bianucci, Pablo

    2014-10-20

    Photonic crystal ring resonators (PhCRR) combine the features of ring resonators with the slow-light effects present in photonic crystal waveguides, resulting in better mode confinement and increased light-matter interaction. When the resonator modes are near the photonic band edge, this enhancement is maximized. However, for this to be useful it is necessary to design the resonator so that these modes are at a desired wavelength. We introduce a design prescription, based on a theoretical analysis of the mode spectrum of PhCRRs, that maximizes these effects at a given wavelength. We test the procedure using numerical simulations, finding a good agreement between the design objectives and the simulated mode structures. We also consider the effects of disorder on the device. PMID:25401637

  12. Transmission enhancement through deep subwavelength apertures using connected split ring resonators.

    PubMed

    Ates, Damla; Cakmak, Atilla Ozgur; Colak, Evrim; Zhao, Rongkuo; Soukoulis, C M; Ozbay, Ekmel

    2010-02-15

    We report astonishingly high transmission enhancement factors through a subwavelength aperture at microwave frequencies by placing connected split ring resonators in the vicinity of the aperture. We carried out numerical simulations that are consistent with our experimental conclusions. We experimentally show higher than 70,000-fold extraordinary transmission through a deep subwavelength aperture with an electrical size of lambda/31 x lambda/12 (width x length), in terms of the operational wavelength. We discuss the physical origins of the phenomenon. Our numerical results predict that even more improvements of the enhancement factors are attainable. Theoretically, the approach opens up the possibility for achieving very large enhancement factors by overcoming the physical limitations and thereby minimizes the dependence on the aperture geometries.

  13. BAY K 8644-induced enhancement of 45Ca uptake by rabbit aortic rings

    SciTech Connect

    Scriabine, A.; Anderson, C.L.; Janis, R.A.

    1986-07-01

    BAY K 8644, a Ca/sup 2 +/ channel activator, enhances uptake of /sup 45/Ca by rabbit aortic rings. This effect depends on the concentration of K/sup +/ in the medium: at 20 mM K/sup +/ the effect of BAY K 8644 was more pronounced than at 5 mM, whereas at 80 mM, no significant enhancement of /sup 45/Ca uptake by BAY K 8644 was found. In the medium containing 5 mM K/sup +/, BAY K 8644 was effective in experiments involving 10 or 30 (but not 3) min exposure of aortic rings to /sup 45/Ca. The dose-response curve for BAY K 8644 was established in 5 mM K/sup +/-containing medium and for 30 min exposure to /sup 45/Ca. BAY K 8644 was effective at 0.01 microM and higher concentrations. In the presence of norepinephrine (0.1 or 10 microM), BAY K 8644 had no greater effect on /sup 45/Ca uptake than in control 5 mM K/sup +/ medium. Our observation that the presence of norepinephrine in 5 mM K/sup +/ did not enhance BAY K 8644-induced /sup 45/Ca uptake suggests that activation of alpha-adrenergic receptor does not depolarize aortic membranes to the same extent as an increase in K+ concentration to 20 mM or that BAY K 8644 does not enhance Ca/sup 2 +/ entry through receptor-operated channels.

  14. Epidemiology of intracranial stenosis.

    PubMed

    Suri, M Fareed K; Johnston, S Claiborne

    2009-10-01

    Intracranial stenosis is a common etiology for ischemic stroke. Due to limitations of imaging studies, there are limited data on the prevalence of symptomatic and asymptomatic intracranial stenosis. Intracranial stenosis is more prevalent in Asian, Hispanic, and African-American populations. The reported proportion of patients with symptomatic intracranial stenosis among those hospitalized for ischemic cerebral events varies from 1% in non-Hispanic whites to as high as 50% in Asian populations. In population-based studies, the estimated prevalence of symptomatic intracranial disease varies from 1 in 100,000 for whites to 15 in 100,000 in African Americans. A Chinese population-based study reported intracranial stenosis in 7% of the population aged more than 40 years. Autopsy studies have noted intracranial atherosclerotic disease in about 23% of population in the 6th decade and 80% of population in the 9th decade of life. Angiotensin-converting enzyme polymorphisms, plasma endostatin/vascular endothelial growth factor ratio, glutathione S-transferase omega-1 gene polymorphism, and plasma homocysteine levels are non-modifiable risk factors noted to be associated with intracranial stenosis. Hypertension and serum lipid profile are major modifiable risk factors, whereas sickle cell disease is an uncommon risk factor that can be managed to reduce risk. Associations of intracranial atherosclerosis with diabetes mellitus, metabolic syndrome, Alzheimer's disease, aortic plaques, radiotherapy, and meningitis are less well documented.

  15. Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

    MedlinePlus

    ... Asked Questions Español Condiciones Chinese Conditions Idiopathic Intracranial Hypertension (Pseudotumor Cerebri) En Español Read in Chinese What is idiopathic intracranial hypertension? Idiopathic intracranial hypertension (IIH) is a disorder that ...

  16. Intracranial capillary hemangioma in an elderly patient

    PubMed Central

    Okamoto, Ai; Nakagawa, Ichiro; Matsuda, Ryosuke; Nishimura, Fumihiko; Motoyama, Yasushi; Park, Young-Su; Nakamura, Mitsutoshi; Nakase, Hiroyuki

    2015-01-01

    Background: Capillary hemangiomas are neoplasms involving skin and soft tissue in infants. These lesions rarely involved an intracranial space and reported age distribution ranges from infancy to middle age. We report an extremely rare case of rapidly rising intracranial capillary hemangioma in an elderly woman. Case Description: The 82-year-old woman presented with vomiting, reduced level of consciousness, and worsening mental state. Computed tomography showed a contrast-enhanced extra-axial lesion in the left frontal operculum, although no intracranial mass lesion was identifiable from magnetic resonance imaging taken 2 years earlier. Complete surgical excision was performed and histopathological examination diagnosed benign capillary hemangioma consisting of a variety of dilated capillary blood vessels lined by endothelial cells. Conclusion: This is the first description of rapid growth of an intracranial capillary hemangioma in an elderly woman. These lesions are exceedingly rare in the elderly population, but still show the capacity for rapid growth. Complete excision would prevent further recurrence. PMID:26664868

  17. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    SciTech Connect

    Mukai, Y.; Hirori, H.; Yamamoto, T.; Kageyama, H.; Tanaka, K.

    2014-07-14

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO{sub 3} crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

  18. SpyRings Declassified: A Blueprint for Using Isopeptide-Mediated Cyclization to Enhance Enzyme Thermal Resilience.

    PubMed

    Schoene, C; Bennett, S P; Howarth, M

    2016-01-01

    Enzymes often have marginal stability, with unfolding typically leading to irreversible denaturation. This sensitivity is a major barrier, both for de novo enzyme development and for expanding enzyme impact beyond the laboratory. Seeking an approach to enhance resilience to denaturation that could be applied to a range of different enzymes, we developed SpyRing cyclization. SpyRings contain genetically encoded SpyTag (13 amino acids) on the N-terminus and SpyCatcher (12kDa) on the C-terminus of the enzyme, so that the Spy partners spontaneously react together through an irreversible isopeptide bond. SpyRing cyclization gave major increases in thermal resilience, including on a model for enzyme evolution, β-lactamase, and an industrially important enzyme in agriculture and nutrition, phytase. We outline the SpyRing rationale, including comparison of SpyRing cyclization to other cyclization strategies. The cloning strategy is presented for the simple insertion of enzyme genes for recombinant expression. We discuss structure-based approaches to select suitable enzyme cyclization targets. Approaches to evaluate the cyclization reaction and its effect on enzyme resilience are described. We also highlight the use of differential scanning calorimetry to understand how SpyRing cyclization promotes enzyme refolding. Efficiently searching sequence space will continue to be important for enzyme improvement, but the SpyRing platform may be a valuable rational adjunct for conferring resilience. PMID:27586332

  19. A Unique Case of Intracranial Mucormycosis Following an Assault

    PubMed Central

    Hussain, Fadilah S

    2016-01-01

    Intracranial mucormycosis is a very unusual presentation of an infection after a depressed skull fracture due to an assault. Only sporadic cases have been reported in the literature previously. A 30-year-old male with a traumatic brain injury following an assault, status-post debridement and elevation of a depressed skull fracture, was discharged home several weeks postoperatively. A CT scan of the head with contrast was obtained due to mental status changes and revealed an enhancing ring-shaped lesion in the right frontal lobe consistent with a brain abscess. The patient was taken to the operating room for image-guided excisional biopsy of the lesion, with pathology revealing mucormycosis. 

  20. A Unique Case of Intracranial Mucormycosis Following an Assault

    PubMed Central

    Hussain, Fadilah S

    2016-01-01

    Intracranial mucormycosis is a very unusual presentation of an infection after a depressed skull fracture due to an assault. Only sporadic cases have been reported in the literature previously. A 30-year-old male with a traumatic brain injury following an assault, status-post debridement and elevation of a depressed skull fracture, was discharged home several weeks postoperatively. A CT scan of the head with contrast was obtained due to mental status changes and revealed an enhancing ring-shaped lesion in the right frontal lobe consistent with a brain abscess. The patient was taken to the operating room for image-guided excisional biopsy of the lesion, with pathology revealing mucormycosis.  PMID:27672528

  1. Primary Intracranial Choriocarcinoma Located in the Suprasellar Region

    PubMed Central

    Li, Xiuli; Murayama, Kazuhiro; Watanabe, Ayumi; Abe, Masato; Toyama, Hiroshi

    2016-01-01

    A 10 year old girl was admitted to our hospital due to headache, nausea, and weight loss for about half a year. She also had visual field disorders. Suprasellar tumor was found by X-ray computed tomography, and magnetic resonance imaging showed a ring-like lobulated enhanced mass with hemorrhage and necrosis. Biopsy of this lesion showed primary intracranial choriocarcinoma on histopathological examination. The serum human chorionic gonadotropin (hCG) level was measured after the biopsy and was elevated at 71,298.2 IU/L. The patient died due to hydrocephalus caused by an increase in the size of the tumor with a larger amount of hemorrhage than the preoperative features. If young patients present with a suprasellar lobulated mass with hemorrhage, the serum hCG level should be measured before operation. PMID:27499824

  2. A Unique Case of Intracranial Mucormycosis Following an Assault.

    PubMed

    Hussain, Fadilah S; Hussain, Namath S

    2016-01-01

    Intracranial mucormycosis is a very unusual presentation of an infection after a depressed skull fracture due to an assault. Only sporadic cases have been reported in the literature previously. A 30-year-old male with a traumatic brain injury following an assault, status-post debridement and elevation of a depressed skull fracture, was discharged home several weeks postoperatively. A CT scan of the head with contrast was obtained due to mental status changes and revealed an enhancing ring-shaped lesion in the right frontal lobe consistent with a brain abscess. The patient was taken to the operating room for image-guided excisional biopsy of the lesion, with pathology revealing mucormycosis. PMID:27672528

  3. Intracranial pressure monitoring

    MedlinePlus

    ICP monitoring; CSF pressure monitoring ... There are 3 ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is the most accurate monitoring method. To insert an intraventricular catheter, a ...

  4. Intracranial presentation of teratocarcinosarcoma.

    PubMed

    Sweety Vijay, Shinde; Kumar, Tyagi Devendra; Srikant, Balasubramaniam; Vithal, Sawant Hemant Kumar; Vijay, Kane Shubda; Gurunath, Puranik

    2010-10-01

    Teratocarcinosarcoma (TCS), an aggressive and extremely rare neoplasm, usually presents as a nasal or paranasal mass. TCS can have intracranial or dural extension from a nasal mass. We found only two instances in the literature that described this lesion as primarily manifesting as an intracranial mass while arising from a primary nasal focus. We describe a patient who had a predominantly frontal-lobe TCS without any symptoms of a primary nasal mass. The gross surgical appearance was a glistening, slimy, firm white mucoid lesion, in contrast to the friable, necrotic and tan-colored lesion usually described. We report a patient with a rare intracranial TCS, and focus on the differential diagnoses of intracranial tumors. Neuropathologists and neurosurgeons should be aware of this mode of presentation for an accurate diagnosis and a well-targeted therapeutic approach.

  5. Hidradenoma with intracranial involvement.

    PubMed

    Bradbury, P G; Diengdoh, J V; Crockard, H A; Stern, G M

    1984-06-01

    A case of recurrent hidradenoma of the external ear with intracranial spread is described. The presentation, classification and management of this rare tumour are discussed and the importance of adequate long term review is stressed.

  6. [Correction of intracranial pressure in patients with traumatic intracranial hemorrhages].

    PubMed

    Virozub, I D; Chipko, S S; Chernovskiĭ, V I; Cherniaev, V A

    1986-01-01

    Therapeutical correction of intracranial pressure changes were conducted in 14 patients suffering from traumatic intracranial hematomas by endolumbar administration of physiological solution. The distinguishing feature of this method is the possibility of continuous control of the intracranial pressure level by means of long-term graphic recording of epidural pressure. This makes it possible to perform endolumbar administration of physiological solution in a dose which is determined by the initial level of epidural intracranial pressure. Therapeutic correction of intracranial pressure by endolumbar injection of physiological solution proved successful in the initial stages of dislocation of the brain and in stable intracranial hypotension.

  7. Enhanced spin figure of merit in an Aharonov-Bohm ring with a double quantum dot

    SciTech Connect

    Zhou, Xingfei; Qi, Fenghua; Jin, Guojun

    2014-04-21

    We theoretically investigate the thermoelectric effects in an Aharonov-Bohm ring with a serially coupled double quantum dot embedded in one arm. An external magnetic field is perpendicularly applied to the two dots. Using the nonequilibrium Green's function method in the linear-response regime, we calculate the charge and spin figures of merit. When the energy levels of the two quantum dots are equal and the system is connected to two normal leads, a large spin figure of merit (Z{sub s}T ≈ 4.5) accompanying with a small charge figure of merit (Z{sub c}T ≈ 0) can be generated due to the remarkable bipolar effect. Further, when the system is connected to two ferromagnetic leads, the spin figure of merit can reach even a higher value about 9. Afterwards, we find that Z{sub s}T is enhanced while Z{sub c}T is reduced in the coaction of the Aharonov-Bohm flux and Rashba spin-orbit coupling. It is argued that the bipolar effect is positive (negative) to spin (charge) figure of merit in the presence of level detuning of the two quantum dots and intradot Coulomb interactions, respectively. Also, we propose a possible experiment to verify our results.

  8. Spatial confinement causes lifetime enhancement and expansion of vortex rings with positive filament tension

    NASA Astrophysics Data System (ADS)

    Totz, Jan Frederik; Engel, Harald; Steinbock, Oliver

    2015-09-01

    We study the impact of spatial confinement on the dynamics of three-dimensional (3D) excitation vortices with circular filaments. In a chemically active medium we observe a decreased contraction rate of such scroll rings and even expanding ones, despite their positive filament tension. All experimentally observed regimes of spatially confined scroll ring evolution are reproduced by full 3D numerical integration of the underlying reaction-diffusion equations. Additionally, we propose a kinematical model that takes into account the interaction of the scroll ring with a no-flux boundary. Its predictions agree quantitatively with data obtained from simulations of the reaction-diffusion model.

  9. [Idiopathic intracranial hypertension].

    PubMed

    Sergeev, A V

    2016-01-01

    Idiopathic intracranial hypertension (IIH) is a condition due to high intracranial pressure in the absence of an intracranial mass lesion, venous thrombosis or brain infection. It mostly occurs in young obese females. Currently, the incidence of IIH in obese women is estimated to be 12 per 100,000 people per year. Epidemiological data demonstrate the increase in incidence in this group: 323 cases per 100,000. IIH can cause visual loss in 1-2% of the patients during the year before the diagnosis and beginning of treatment. IIH treatment is a complex multidisciplinary problem that includes a body-mass reduction program, conservative pharmacological treatment, prolonged ophthalmological study and, if necessary, timely neurosurgical treatment.

  10. Intracranial infantile hemangiopericytoma.

    PubMed

    McHugh, Brian J; Baranoski, Jacob F; Malhotra, Ajay; Vortmeyer, Alexander O; Sze, Gordon; Duncan, Charles C

    2014-08-01

    Intracranial infantile hemangiopericytomas (HPCs) are exceedingly rare lesions. Only 11 cases have been previously reported in the literature. As such, little is known about the etiology, long-term prognosis, and optimal treatment paradigm. Clinically, they are consistently less aggressive than those in adults. The authors present the case of a 2-month-old boy with an intracranial HPC, review the available literature, discuss the evolving concepts of what defines an HPC, and offer a potential explanation to how HPC histology might relate to the clinical behavior of these lesions.

  11. Combined 3 Tesla MRI Biomarkers Improve the Differentiation between Benign vs Malignant Single Ring Enhancing Brain Masses

    PubMed Central

    Salice, Simone; Esposito, Roberto; Ciavardelli, Domenico; delli Pizzi, Stefano; di Bastiano, Rossella; Tartaro, Armando

    2016-01-01

    Purpose To evaluate whether the combination of imaging biomarkers obtained by means of different 3 Tesla (3T) Magnetic Resonance Imaging (MRI) advanced techniques can improve the diagnostic accuracy in the differentiation between benign and malignant single ring-enhancing brain masses. Materials and Methods 14 patients presenting at conventional 3T MRI single brain mass with similar appearance as regard ring enhancement, presence of peri-lesional edema and absence of hemorrhage signs were included in the study. All lesions were histologically proven: 5 pyogenic abscesses, 6 glioblastomas, and 3 metastases. MRI was performed at 3 Tesla and included Diffusion Weighted Imaging (DWI), Dynamic Susceptibility Contrast -Perfusion Weighted Imaging (DSC-PWI), Magnetic Resonance Spectroscopy (MRS), and Diffusion Tensor Imaging (DTI). Imaging biomarkers derived by those advanced techniques [Cerebral Blood Flow (CBF), relative Cerebral Blood Volume (rCBV), relative Main Transit Time (rMTT), Choline (Cho), Creatine (Cr), Succinate, N-Acetyl Aspartate (NAA), Lactate (Lac), Lipids, relative Apparent Diffusion Coefficient (rADC), and Fractional Anisotropy (FA)] were detected by two experienced neuroradiologists in joint session in 4 areas: Internal Cavity (IC), Ring Enhancement (RE), Peri-Lesional edema (PL), and Contralateral Normal Appearing White Matter (CNAWM). Significant differences between benign (n = 5) and malignant (n = 9) ring enhancing lesions were tested with Mann-Withney U test. The diagnostic accuracy of MRI biomarkers taken alone and MRI biomarkers ratios were tested with Receiver Operating Characteristic (ROC) analysis with an Area Under the Curve (AUC) ≥ 0.9 indicating a very good diagnostic accuracy of the variable. Results Five MRI biomarker ratios achieved excellent accuracy: IC-rADC/PL-NAA (AUC = 1), IC-rADC/IC-FA (AUC = 0.978), RE-rCBV/RE-FA (AUC = 0.933), IC-rADC/RE-FA (AUC = 0.911), and IC-rADC/PL-FA (AUC = 0.911). Only IC-rADC achieved a very good

  12. Floating field ring technique applied to enhance fill factor of silicon photomultiplier elementary cell

    NASA Astrophysics Data System (ADS)

    Maresca, L.; De Laurentis, M.; Riccio, M.; Irace, A.; Breglio, G.

    2011-06-01

    A silicon photomultiplier (SiPM) is a matrix of Geiger-mode avalanche photodiodes (GM-APDs) connected in parallel. One of the main drawback in the SiPm is the low Photon Detection Efficiency(PDE) also due to the low geometrical fill factor of the microcells array. This paper reports on the analysis and simulation of the single floating field ring technique, applied to the junction termination of the single cell of a Silicon Photomultiplier (SiPm). A floating guard ring is made along the border of the single microcell and it is not connected to the cathodic contact. Even if the ring is not electrically connected to the main junction, it mitigates the variation of the electrical field at the main termination. The effect of the junction-to-ring distance is analytically investigated by using cylindrical coordinates and an optimal distance together with the optimal width is found. Results show that the single floating ring reduces the junction edge electric field by keeping constant the size of the microcell allowing, then, an improvement for the geometrical fill factor. Results are supported by TCAD simulations.

  13. Primary Intracranial Synovial Sarcoma

    PubMed Central

    Li, Luyuan; Sinson, Grant; Mueller, Wade

    2016-01-01

    Background. Synovial sarcoma is an aggressive soft tissue sarcoma with uncertain histological origin. The pathology frequently presents as a localized disease, especially near large joints around the knee and thigh. Intracranial disease, which is rare, has been reported as metastasis from synovial sarcoma. We report a case with no obvious primary extracranial pathology, suggesting primary intracranial disease; this has not been reported in the literature. Case Description. A 21-year-old male, with a prior right skull lesion resection for atypical spindle cell neoplasm, presented with headaches, gait instability, left arm weakness, and left homonymous hemianopsia. CT of head demonstrated a right parietal hemorrhagic lesion with mass effect, requiring surgical decompression. Histopathology revealed synovial sarcoma. FISH analysis noted the existence of the t(X;18)(p11.2;q11.2) chromosomal translocation. PET scan did not show other metastatic disease. He underwent stereotactic radiotherapy and adjuvant chemotherapy. At 2-year follow-up, he remained nonfocal without recurrence. Conclusion. We report the first known case of primary intracranial synovial sarcoma. Moreover, we stress that intracranial lesions may have a tendency for hemorrhage, requiring urgent lifesaving decompression. PMID:27247811

  14. Primary Intracranial Synovial Sarcoma.

    PubMed

    Patel, Mohit; Li, Luyuan; Nguyen, Ha Son; Doan, Ninh; Sinson, Grant; Mueller, Wade

    2016-01-01

    Background. Synovial sarcoma is an aggressive soft tissue sarcoma with uncertain histological origin. The pathology frequently presents as a localized disease, especially near large joints around the knee and thigh. Intracranial disease, which is rare, has been reported as metastasis from synovial sarcoma. We report a case with no obvious primary extracranial pathology, suggesting primary intracranial disease; this has not been reported in the literature. Case Description. A 21-year-old male, with a prior right skull lesion resection for atypical spindle cell neoplasm, presented with headaches, gait instability, left arm weakness, and left homonymous hemianopsia. CT of head demonstrated a right parietal hemorrhagic lesion with mass effect, requiring surgical decompression. Histopathology revealed synovial sarcoma. FISH analysis noted the existence of the t(X;18)(p11.2;q11.2) chromosomal translocation. PET scan did not show other metastatic disease. He underwent stereotactic radiotherapy and adjuvant chemotherapy. At 2-year follow-up, he remained nonfocal without recurrence. Conclusion. We report the first known case of primary intracranial synovial sarcoma. Moreover, we stress that intracranial lesions may have a tendency for hemorrhage, requiring urgent lifesaving decompression. PMID:27247811

  15. Enhanced ductility in round tensile bars produced by cladding a ductile ring

    NASA Astrophysics Data System (ADS)

    Chen, X. X.; Wu, P. D.; Embury, J. D.; Huang, Y.

    2010-03-01

    The effect of cladding a ductile ring on necking and fracture in round bars under tension is studied numerically using the finite element method based on the Gurson damage model. It is demonstrated that the cladding increases both the necking strain and the fracture strain. The effects of topological arrangement of cladding ring on necking and fracture are numerically investigated. It is indicated that while a topological arrangement of cladding has no noticeable effect on necking, it significantly influences the fracture strain. For a given volume fraction of cladding, the fracture strain could increase about 11% if the ductile ring is moved from the outmost to the innermost. It is also found that the subtle appearance of fracture surface due to cladding displays strong mesh sensitivity and may even be an artefact of the mesh.

  16. Noncontrast-enhanced three-dimensional (3D) intracranial MR angiography using pseudocontinuous arterial spin labeling and accelerated 3D radial acquisition.

    PubMed

    Wu, Huimin; Block, Walter F; Turski, Patrick A; Mistretta, Charles A; Johnson, Kevin M

    2013-03-01

    Pseudocontinuous arterial spin labeling (PCASL) can be used to generate noncontrast magnetic resonance angiograms of the cerebrovascular structures. Previously described PCASL-based angiography techniques were limited to two-dimensional projection images or relatively low-resolution three-dimensional (3D) imaging due to long acquisition time. This work proposes a new PCASL-based 3D magnetic resonance angiography method that uses an accelerated 3D radial acquisition technique (VIPR, spoiled gradient echo) as the readout. Benefiting from the sparsity provided by PCASL and noise-like artifacts of VIPR, this new method is able to obtain submillimeter 3D isotropic resolution and whole head coverage with a 8-min scan. Intracranial angiography feasibility studies in healthy (N = 5) and diseased (N = 5) subjects show reduced saturation artifacts in PCASL-VIPR compared with a standard time-of-flight protocol. These initial results show great promise for PCASL-VIPR for static, dynamic, and vessel selective 3D intracranial angiography. PMID:22532423

  17. Intracranial juvenile nasopharyngeal angiofibroma.

    PubMed

    Wylie, J P; Slevin, N J; Johnson, R J

    1998-01-01

    We report the case history of a 26-year-old man who was diagnosed with advanced juvenile nasopharyngeal angiofibroma with intracranial extension. The lesion was considered to be inoperable and the patient was treated with radical radiotherapy. Serial magnetic resonance imaging has shown continued tumour regression and he remains well after 3 years. The literature is reviewed and radiotherapy recommended as the modality of choice for these patients.

  18. Air-ring microstructure arrays for enhanced light extraction from a face-up light-emitting diode.

    PubMed

    Kim, Hyun Kyu; Park, Young Jae; Kang, Ji Hye; Han, Nam; Han, Min; Ryu, Beo Deul; Ko, Kang Bok; Yang, Jong Han; Kim, Young Taek; Chandramohan, S; Jeong, Hyun; Jeong, Mun Seok; Hong, Chang-Hee

    2013-05-01

    In this Letter, a light-emitting diode (LED) with prism-shaped-air-ring microstructures (PSAMs) formed on flat sapphire substrate is demonstrated as an alternative design to face-up LEDs on patterned sapphire substrate (PSS) for enhanced light extraction efficiency. In this LED design, the emitted photons can be deflected to the top of the chip for its effective extraction, contrary to the PSS-LED wherein photons are guided to sapphire and get absorbed by packaging materials. The PSAM-LED showed an enhancement in the radiometric power as high as 10% with a low far-field angle of 129° over that of a PSS-LED under an injection current of 20 mA. PMID:23632528

  19. Pediatric intracranial aneurysms.

    PubMed

    Tripathy, L N; Singh, S N

    2009-01-01

    The incidence of subarachnoid haemorrhage from intracranial aneurysms in the paediatric age group is extremely rare. Interestingly, occurrence of vasospasm has been reported to be less in comparison to the adults. Both coiling and clipping have been advocated in selected cases. Because of the thinness of the wall of the arteries, utmost care should be taken while handling these arteries during surgery. The overall results of surgery in children have been reported to be better than their adult counterparts. We present four such cases from our own experience. All these children were operated upon, where the solitary aneurysm in each case was clipped and all of them made a good recovery.

  20. Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

    DOE PAGES

    Carpenter, Barry K.; Harvey, Jeremy N.; Glowacki, David R.

    2014-12-11

    Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). In this study, the achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent–solute interactions within the first ~100 fsmore » of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the “decision” about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.« less

  1. Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

    SciTech Connect

    Carpenter, Barry K.; Harvey, Jeremy N.; Glowacki, David R.

    2014-12-11

    Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). In this study, the achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent–solute interactions within the first ~100 fs of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the “decision” about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.

  2. Giant Electric Field Enhancement in Split Ring Resonators Featuring Nanometer-Sized Gaps

    PubMed Central

    Bagiante, S.; Enderli, F.; Fabiańska, J.; Sigg, H.; Feurer, T.

    2015-01-01

    Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales. Driven by standard laser sources THz electric field strengths of up to several MVm−1 have been reported and in order to reach even higher electric field strengths the use of dedicated electric field enhancement structures has been proposed. Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz. These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations. PMID:25623373

  3. Network connectivity enhancement by exploiting all optical multicast in semiconductor ring laser

    NASA Astrophysics Data System (ADS)

    Siraj, M.; Memon, M. I.; Shoaib, M.; Alshebeili, S.

    2015-03-01

    The use of smart phone and tablet applications will provide the troops for executing, controlling and analyzing sophisticated operations with the commanders providing crucial documents directly to troops wherever and whenever needed. Wireless mesh networks (WMNs) is a cutting edge networking technology which is capable of supporting Joint Tactical radio System (JTRS).WMNs are capable of providing the much needed bandwidth for applications like hand held radios and communication for airborne and ground vehicles. Routing management tasks can be efficiently handled through WMNs through a central command control center. As the spectrum space is congested, cognitive radios are a much welcome technology that will provide much needed bandwidth. They can self-configure themselves, can adapt themselves to the user requirement, provide dynamic spectrum access for minimizing interference and also deliver optimal power output. Sometimes in the indoor environment, there are poor signal issues and reduced coverage. In this paper, a solution utilizing (CR WMNs) over optical network is presented by creating nanocells (PCs) inside the indoor environment. The phenomenon of four-wave mixing (FWM) is exploited to generate all-optical multicast using semiconductor ring laser (SRL). As a result same signal is transmitted at different wavelengths. Every PC is assigned a unique wavelength. By using CR technology in conjunction with PC will not only solve network coverage issue but will provide a good bandwidth to the secondary users.

  4. Enhanced stripe phases in spin-orbit-coupled Bose-Einstein condensates in ring cavities

    NASA Astrophysics Data System (ADS)

    Mivehvar, Farokh; Feder, David L.

    2015-08-01

    The coupled dynamics of the atom and photon fields in optical ring cavities with two counterpropagating modes give rise to both spin-orbit interactions as well as long-ranged interactions between atoms of a many-body system. At zero temperature, the interplay between the two-body and cavity-mediated interactions determines the ground state of a Bose-Einstein condensate. In this work, we find that cavity quantum electrodynamics in the weak-coupling regime favors a stripe-phase state over a plane-wave phase as the strength of cavity-mediated interactions increases. Indeed, the stripe phase is energetically stabilized even for condensates with attractive intraspecies and interspecies interactions for sufficiently large cavity interactions. The elementary excitation spectra in both phases correspond to linear dispersion relation at long wavelengths, indicating that both phases exhibit superfluidity, although the plane-wave phase also displays a characteristic roton-type feature. The results suggest that even in the weak-coupling regime, cavities can yield interesting new physics in ultracold quantum gases.

  5. Gold Nanoparticle Coated Carbon Nanotube Ring with Enhanced Raman Scattering and Photothermal Conversion Property for Theranostic Applications.

    PubMed

    Song, Jibin; Wang, Feng; Yang, Xiangyu; Ning, Bo; Harp, Mary G; Culp, Stephen H; Hu, Song; Huang, Peng; Nie, Liming; Chen, Jingyi; Chen, Xiaoyuan

    2016-06-01

    We report a new type of carbon nanotube ring (CNTR) coated with gold nanoparticles (CNTR@AuNPs) using CNTR as a template and surface attached redox-active polymer as a reducing agent. This nanostructure of CNTR bundle embedded in the gap of closely attached AuNPs can play multiple roles as a Raman probe to detect cancer cells and a photoacoustic (PA) contrast agent for imaging-guided cancer therapy. The CNTR@AuNP exhibits substantially higher Raman and optical signals than CNTR coated with a complete Au shell (CNTR@AuNS) and straight CNT@AuNP. The extinction intensity of CNTR@AuNP is about 120-fold higher than that of CNTR at 808 nm, and the surface enhanced Raman scattering (SERS) signal of CNTR@AuNP is about 110 times stronger than that of CNTR, presumably due to the combined effects of enhanced coupling between the embedded CNTR and the plasmon mode of the closely attached AuNPs, and the strong electromagnetic field in the cavity of the AuNP shell originated from the intercoupling of AuNPs. The greatly enhanced PA signal and photothermal conversion property of CNTR@AuNP were successfully employed for imaging and imaging-guided cancer therapy in two tumor xenograft models. Experimental observations were further supported by numerical simulations and perturbation theory analysis. PMID:27193381

  6. Patient-controlled intracranial pressure for managing idiopathic intracranial hypertension.

    PubMed

    Werndle, Melissa C; Newling-Ward, Elizabeth; Papadopoulos, Marios C

    2015-01-01

    Idiopathic intracranial hypertension is a difficult condition to manage. We present a novel treatment that substantially improved the headaches and reduced admissions and shunt revision surgery in a patient. We inserted a ventriculoperitoneal shunt, performed subtemporal craniectomies, and instructed our patient to apply different sized headbands to allow her to anticipate and control her own intracranial pressure: a tight headband for low-pressure headaches; no band for high-pressure headaches. Magnetic resonance imaging and intracranial pressure monitoring revealed this was not a placebo effect.

  7. Rings of saturn-like” nanoarrays with high number density of hot spots for surface-enhanced Raman scattering

    SciTech Connect

    Dai, Zhigao; Liao, Lei; Wu, Wei; Guo, Shishang; Zhao, Xinyue; Li, Wei; Ren, Feng; Jiang, Changzhong E-mail: czjiang@whu.edu.cn; Mei, Fei; Xiao, Xiangheng E-mail: czjiang@whu.edu.cn; Fu, Lei; Wang, Jiao

    2014-07-21

    The Ag nanoparticles (NPs) surrounding triangular nanoarrays (TNAs) with high number density of surface-enhanced Raman scattering (SERS) hot spots (SERS hot spots ring) are prepared by a combination of NPs deposition and subsequent colloid lithography processing. Owing to the SERS hot spots ring, the Ag NPs surrounding TNAs have been proved an excellent candidate for ultrasensitive molecular sensing for their high SERS signal enhancing capacity in experiments and theories. The Ag NPs surrounding TNAs can be readily used for the quick detection of low concentrations of molecules related to food safety; herein, detection of melamine is discussed.

  8. Telemetry of intracranial pressure

    NASA Technical Reports Server (NTRS)

    Fryer, T. B.; Corbin, S. D.; Silverberg, G. D.; Schmidt, E. V.; Ream, A. K.

    1978-01-01

    A completely implantable epidural pressure telemetry system designed for accurate measurement of intracranial pressure (ICP) is described. The implant device is batteryless, providing unlimited operating life. The described system uses a capacitive pressure transducer with excellent long-term stability. Once detected with the transducer and converted to a frequency with the oscillator electronics, the pressure signal is digitized. It is then telemetered without the possibility of further degradation. After detection with the small external module, the data can be retransmitted by a radio link for complete patient mobility or the energizer signal pickup module can be wired to a bedside readout unit. Continuous data are available from the system so that the dynamic ICP changes reflecting arterial blood pressure can be observed and used for diagnosis.

  9. Intracranial aneurysm and sildenafil.

    PubMed

    Adiga, Avinash; Edriss, Hawa; Nugent, Kenneth

    2016-04-01

    Sildenafil is one of the most commonly used drugs for the treatment of erectile dysfunction. To date, we found five reported cases of intracerebral bleeding and two reported cases of subarachnoid hemorrhage related to sildenafil use. We report a 49-year-old hypertensive and diabetic patient who presented with acute pulmonary edema and loss of consciousness following ingestion of 100 mg of sildenafil prior to sexual intercourse. He was not previously aware of the presence of an aneurysm and had no family history of it. Computed tomography of his head revealed a subarachnoid hemorrhage due to rupture of a saccular aneurysm with subsequent repeat hemorrhage within a few hours of presentation. A sudden increase in blood pressure led to pulmonary edema. Studies have shown that sildenafil acts on phosphodiesterase-1, -2 and -5 receptors and leads to a secondary increase in intracerebral circulation and vasodilatory effects, leading to sympathetic overactivity which increases the risk for intracranial bleeding. PMID:27034561

  10. Intracranial aneurysm and sildenafil

    PubMed Central

    Edriss, Hawa; Nugent, Kenneth

    2016-01-01

    Sildenafil is one of the most commonly used drugs for the treatment of erectile dysfunction. To date, we found five reported cases of intracerebral bleeding and two reported cases of subarachnoid hemorrhage related to sildenafil use. We report a 49-year-old hypertensive and diabetic patient who presented with acute pulmonary edema and loss of consciousness following ingestion of 100 mg of sildenafil prior to sexual intercourse. He was not previously aware of the presence of an aneurysm and had no family history of it. Computed tomography of his head revealed a subarachnoid hemorrhage due to rupture of a saccular aneurysm with subsequent repeat hemorrhage within a few hours of presentation. A sudden increase in blood pressure led to pulmonary edema. Studies have shown that sildenafil acts on phosphodiesterase-1, -2 and -5 receptors and leads to a secondary increase in intracerebral circulation and vasodilatory effects, leading to sympathetic overactivity which increases the risk for intracranial bleeding. PMID:27034561

  11. Unruptured Intracranial Aneurysms

    PubMed Central

    Raymond, J.; Guillemin, F.; Proust, F.; Molyneux, A.J.; Fox, A.J.; Claiborne, J.S.; Meder, J.-F.; Rouleau, I.

    2008-01-01

    Summary The preventive treatment of unruptured aneur­ysms has been performed for decades despite the lack of evidence of a clinical benefit. Reports of observational studies such as the International Study of Unruptured Intracranial Aneurysms (ISUIA) suggest that preventive treatments are rarely justified. Are these reports compelling enough to guide clinical practice? The ISUIA methods and data are reviewed and analysed in a more conventional manner. The design of the appropriate clinical research program is approached by steps, reviewing potential problems, from the formulation of the precise research question to the interpretation of subgroup analyses, including sample size, representativity, duration of observation period, blin­ding, definition of outcome events, analysis of cross-overs, losses to follow-up, and data reporting. Unruptured intracranial aneurysms observed in ISUIA ruptured at a minimal annual rate of 0.8% (0.5-1%), despite multiple methodological difficulties biased in favour of a benign natural history. Available registries do not have the power or the design capable of providing normative guidelines for clinical decisions. The appropriate method to solve the clinical dilemma is a multicentric trial comparing the incidence of a hard clinical outcome events in approximately 2000 patients randomly allocated to a treatment group and a deferred treatment group, all followed for ten years or more. Observational studies have failed to provide reliable evidence in favour or against the preventive treatment of unruptured aneurysms. A randomized trial is in order to clarify what is the role of prevention in this common clinical problem. PMID:20557790

  12. Performance Enhancement of Space-Time Adaptive Processing for GPS and Microstrip Antenna Design Using Ferrite Rings

    NASA Astrophysics Data System (ADS)

    Rivera-Albino, Alix

    Global Positioning System (GPS) is a navigation system widely used in civilian and military application, but its accuracy is highly impacted with consequential fading, and possible loss of communication due to multipath propagation and high power interferences. This dissertation proposes alternatives to improve the performance of the GPS receivers to obtain a system that can be reliable in critical situations. The basic performance of the GPS receiver consists of receiving the signal with an antenna array, delaying the signal at each antenna element, weighting the delayed replicas, and finally, combining the weighted replicas to estimate the desired signal. Based on these, three modifications are proposed to improve the performance of the system. The first proposed modification is the use of the Least Mean Squares (LMS) algorithm with two variations to decrease the convergence time of the classic LMS while achieving good system stability. The results obtained by the proposed LMS demonstrate that the algorithm can achieve the same stability as the classic LMS using a small step size, and its convergence rate is better than the classic LMS using a large step size. The second proposed modification is to replace the uniform distribution of the time delays (or taps) by an exponential distribution that decreases the bit-error rate (BER) of the system without impacting the computational efficiency of the uniform taps. The results show that, for a BER of 0.001, the system can operate with a 1 to 2 dB lower signal-to-noise ratio (SNR) when an exponential distribution is used rather than a uniform distribution. Finally, the third modification is implemented in the design of the antenna array. In this case, the gain of each microstrip element is enhanced by embedding ferrite rings in the substrate, creating a hybrid substrate. The ferrite rings generates constructive interference between the incident and reflected fields; consequently, the gain of a single microstrip element

  13. Sphenoethmoidal mucoceles with intracranial extension.

    PubMed

    Close, L G; O'Conner, W E

    1983-08-01

    Mucoceles of the paranasal sinuses are benign, expansile, locally destructive lesions that are thought to occur secondary to obstruction of the sinus ostia. Nasal and/or ocular signs and symptoms are the usual clinical manifestations of mucoceles arising in the ethmoid and sphenoid sinuses, and intracranial extension is rare. We describe three cases of widely destructive sphenoethmoidal mucoceles extending intracranially, with bone erosion and dural exposure in all cases and brain necrosis in one case.

  14. An Intracranial Gliosis Mimicking Neoplasm: A Dilemma

    PubMed Central

    Shao, Zhi-hong; Wang, Guo-liang; Yi, Xiang-hua; Wang, Pei-jun

    2016-01-01

    Intracranial gliosis has no typical clinical signals or imaging characteristics. Therefore, it can be easily misdiagnosed as neoplasm. Hereby, we report a unique case of gliosis that grew outward from the surface of the brain. MRI depicted its signal and enhancement pattern similar to the cerebral gray matter. The diagnosis was confirmed by pathology and immunohistochemistry. Although it was difficult to reach a diagnosis, correlating its origin, growing pattern and MR features and knowing that gliosis can present this way may help in differentiating it from other diseases.

  15. A fluorometric microarray with ZnO substrate-enhanced fluorescence and suppressed ``coffee-ring'' effects for fluorescence immunoassays

    NASA Astrophysics Data System (ADS)

    Li, Shuying; Dong, Minmin; Li, Rui; Zhang, Liyan; Qiao, Yuchun; Jiang, Yao; Qi, Wei; Wang, Hua

    2015-11-01

    A glass slide was first patterned with hydrophobic hexadecyltrimethoxysilane (HDS) and then microspotted with hydrophilic ZnO nanoparticles in an aminopropyltriethoxysilane (APS) matrix. The resulting HDS-ZnO-APS microarray could present the capability of suppressing the undesirable ``coffee-ring'' effects through its hydrophobic pattern so as to allow the fabrication of ZnO-APS testing microspots with a highly dense and uniform distribution. The lotus-like ``self-cleaning'' function could also be expected to effectively curb the cross contamination of multiple sample droplets. More importantly, the introduction of ZnO nanoparticles could endow the testing microspots with substrate-enhanced fluorescence leading to signal-amplification microarray fluorometry. The practical application of the developed HDS-ZnO-APS microarray was investigated by the sandwiched fluorometric immunoassays of human IgG, showing a linear detection range from 0.010 to 10.0 ng mL-1. Such a throughput-improved fluorometric microarray could be tailored for probing multiple biomarkers in complicated media like serum or blood.A glass slide was first patterned with hydrophobic hexadecyltrimethoxysilane (HDS) and then microspotted with hydrophilic ZnO nanoparticles in an aminopropyltriethoxysilane (APS) matrix. The resulting HDS-ZnO-APS microarray could present the capability of suppressing the undesirable ``coffee-ring'' effects through its hydrophobic pattern so as to allow the fabrication of ZnO-APS testing microspots with a highly dense and uniform distribution. The lotus-like ``self-cleaning'' function could also be expected to effectively curb the cross contamination of multiple sample droplets. More importantly, the introduction of ZnO nanoparticles could endow the testing microspots with substrate-enhanced fluorescence leading to signal-amplification microarray fluorometry. The practical application of the developed HDS-ZnO-APS microarray was investigated by the sandwiched fluorometric

  16. Influence of ring size on the cognition-enhancing activity of DM235 and MN19, two potent nootropic drugs.

    PubMed

    Guandalini, L; Martini, E; Di Cesare Mannelli, L; Dei, S; Manetti, D; Scapecchi, S; Teodori, E; Ghelardini, C; Romanelli, M N

    2012-03-01

    A series of analogs of DM235 and MN19, characterized by rings with different size, have been prepared and evaluated for their nootropic activity in the mouse passive-avoidance test. It was found that the optimal ring size for the analogs of DM235, showing endocyclic both amidic groups, is 6 or 7 atoms. For the compounds structurally related to MN19, carrying an exocyclic amide group, the piperidine ring is the moiety which gives the most interesting compounds.

  17. Nonlocal Intracranial Cavity Extraction

    PubMed Central

    Manjón, José V.; Eskildsen, Simon F.; Coupé, Pierrick; Romero, José E.; Collins, D. Louis; Robles, Montserrat

    2014-01-01

    Automatic and accurate methods to estimate normalized regional brain volumes from MRI data are valuable tools which may help to obtain an objective diagnosis and followup of many neurological diseases. To estimate such regional brain volumes, the intracranial cavity volume (ICV) is often used for normalization. However, the high variability of brain shape and size due to normal intersubject variability, normal changes occurring over the lifespan, and abnormal changes due to disease makes the ICV estimation problem challenging. In this paper, we present a new approach to perform ICV extraction based on the use of a library of prelabeled brain images to capture the large variability of brain shapes. To this end, an improved nonlocal label fusion scheme based on BEaST technique is proposed to increase the accuracy of the ICV estimation. The proposed method is compared with recent state-of-the-art methods and the results demonstrate an improved performance both in terms of accuracy and reproducibility while maintaining a reduced computational burden. PMID:25328511

  18. Nonlocal intracranial cavity extraction.

    PubMed

    Manjón, José V; Eskildsen, Simon F; Coupé, Pierrick; Romero, José E; Collins, D Louis; Robles, Montserrat

    2014-01-01

    Automatic and accurate methods to estimate normalized regional brain volumes from MRI data are valuable tools which may help to obtain an objective diagnosis and followup of many neurological diseases. To estimate such regional brain volumes, the intracranial cavity volume (ICV) is often used for normalization. However, the high variability of brain shape and size due to normal intersubject variability, normal changes occurring over the lifespan, and abnormal changes due to disease makes the ICV estimation problem challenging. In this paper, we present a new approach to perform ICV extraction based on the use of a library of prelabeled brain images to capture the large variability of brain shapes. To this end, an improved nonlocal label fusion scheme based on BEaST technique is proposed to increase the accuracy of the ICV estimation. The proposed method is compared with recent state-of-the-art methods and the results demonstrate an improved performance both in terms of accuracy and reproducibility while maintaining a reduced computational burden. PMID:25328511

  19. Expression of a gene encoding a rice RING zinc-finger protein, OsRZFP34, enhances stomata opening.

    PubMed

    Hsu, Kuo-Hsuan; Liu, Chia-Chin; Wu, Shaw-Jye; Kuo, Ying-Yu; Lu, Chung-An; Wu, Ching-Rong; Lian, Pei-Jyun; Hong, Chwan-Yang; Ke, Yi-Ting; Huang, Juin-Hua; Yeh, Ching-Hui

    2014-09-01

    By oligo microarray expression profiling, we identified a rice RING zinc-finger protein (RZFP), OsRZFP34, whose gene expression increased with high temperature or abscisic acid (ABA) treatment. As compared with the wild type, rice and Arabidopsis with OsRZFP34 overexpression showed increased relative stomata opening even with ABA treatment. Furthermore, loss-of-function mutation of OsRZFP34 and AtRZFP34 (At5g22920), an OsRZFP34 homolog in Arabidopsis, decreased relative stomata aperture under nonstress control conditions. Expressing OsRZFP34 in atrzfp34 reverted the mutant phenotype to normal, which indicates a conserved molecular function between OsRZFP34 and AtRZFP34. Analysis of water loss and leaf temperature under stress conditions revealed a higher evaporation rate and cooling effect in OsRZFP34-overexpressing Arabidopsis and rice than the wild type, atrzfp34 and osrzfp34. Thus, stomata opening, enhanced leaf cooling, and ABA insensitivity was conserved with OsRZFP34 expression. Transcription profiling of transgenic rice overexpressing OsRZFP34 revealed many genes involved in OsRZFP34-mediated stomatal movement. Several genes upregulated or downregulated in OsRZFP34-overexpressing plants were previously implicated in Ca(2+) sensing, K(+) regulator, and ABA response. We suggest that OsRZFP34 may modulate these genes to control stomata opening.

  20. Endovascular treatment of intracranial aneurysms.

    PubMed

    Diaz, Orlando; Rangel-Castilla, Leonardo

    2016-01-01

    Intracranial aneurysms are abnormal dilations of the intracranial vessels, in which all the layers of the vascular wall are affected by degenerative changes that lead to distension of the vessel. Intracranial aneurysms can be classified based on their anatomic location, size, and morphology. Subarachnoid hemorrhage is the most devastating clinical presentation. The goal of preventing hemorrhage or rehemorrhage can only be achieved by excluding the aneurysm from the cerebral circulation. Endovascular or surgical clipping can achieve this goal. Multiple surgical and endovascular approaches have been described for treatment of intracranial aneurysm. Surgical approaches for anterior-circulation intracranial aneurysms include: pterional, orbitozygomatic, and lateral supraorbital craniotomies. Modern microsurgical techniques involve skull base dissection to achieve adequate exposure with minimal brain retraction. Endovascular techniques can be divided into: parent artery reconstruction with coil deposition (primary coil, balloon-assisted coiling, stent-assisted coiling, and other new techniques such as neck reconstruction devices and intraluminal occlusion devices); reconstruction with flow diversion; and deconstructive techniques with involving parent artery sacrifice with or without bypass. PMID:27430470

  1. Management of Symptomatic Intracranial Stenosis.

    PubMed

    Hoak, David A; Lutsep, Helmi L

    2016-09-01

    Intracranial atherosclerotic disease is a common cause of stroke worldwide, causing approximately 10 % of strokes in the USA and up to 50 % in Asian populations. Recurrent stroke risks are particularly high in those with a stenosis of 70 % or more and a recent transient ischemic attack or stroke. Warfarin has been associated with higher major hemorrhage rates and no reduction of recurrent stroke compared to aspirin in patients with symptomatic intracranial stenosis. After early trials showed the feasibility of stenting, two randomized trials compared stenting plus medical management to medical management alone in symptomatic intracranial stenosis. Stenting was linked with increased risk and showed no benefit in any subpopulation of patients. Aggressive medical management in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial was associated with half the risk of stroke compared to that in similar patients in a previous symptomatic intracranial stenosis trial after adjustment of confounding characteristics. Aggressive medical management comprises risk factor control, including a target systolic blood pressure <140 mmHg, a low density lipoprotein <70 mg/dL, hemoglobin A1C <7.0 %, and lifestyle management that incorporates exercise, smoking cessation and weight management, and the use of antithrombotics. PMID:27443379

  2. Intramedullary spinal cord and leptomeningeal metastases from intracranial low-grade oligodendroglioma.

    PubMed

    Verma, Nipun; Nolan, Craig; Hirano, Miki; Young, Robert J

    2014-01-01

    We present an unusual case of a patient with an intracranial low-grade oligodendroglioma who developed recurrence with an intramedullary spinal cord metastasis and multiple spinal leptomeningeal metastases. The intramedullary spinal cord metastasis showed mild enhancement similar to the original intracranial primary, while the multiple spinal leptomeningeal metastases revealed no enhancement. This is the seventh reported case of symptomatic intramedullary spinal cord metastasis from a low-grade oligodendroglioma.

  3. Primary intracranial lymphomas

    PubMed Central

    Mufti, Shagufta T.; Baeesa, Saleh S.; Al-Maghrabi, Jaudah A.

    2016-01-01

    Background: Primary CNS lymphoma (PCNSL), a rare form of aggressive extranodal non-Hodgkin's lymphoma (NHL), has increased in incidence during the last three decades and occurs in both immune compromised and immune competent hosts. It has an overall poor prognosis. Objective: This study attempts to further delineate the clinico-pathological, immunohistochemical and radiological profile of PCNSL at Jeddah to King Faisal Hospital and Research Center. Methods: Computerized search through the archives of King Faisal Hospital and Research Centre between July 2000- December 2012 identified 15 patients with pathologically confirmed PCNSL. These were analyzed retrospectively. Their clinico-pathological, immunohistochemical and radiological data were analyzed. Results: Of the 15 PCNSL patients, 8 (53.3%) were females and 7 (46.6%) were males. There was female predilection especially in the age group of 40-59 years. Mean age at diagnosis for all patients was 50.4 years. There was no patient in the pediatric age group. The most common location in the brain was the frontal region in 7 patients (46.6%), 7 (46.6%) had multiple intracranial masses; all 15 (100%) were Non Hodgkin B-cell lymphomas, among which 13 (86.6%) were diffuse large B-cell lymphomas. All 15 (100%) cases showed diffuse and strong positivity for CD 45, and CD 20. Fourteen patients were immune competent while one was immune compromised. Conclusions: PCNSL often occurs in middle-aged and aged patients. There is female predilection especially in the middle age. Frontal region is the most common location with diffuse large B-cell lymphoma being the predominant subtype. PMID:27366250

  4. Bimetallic 3D nanostar dimers in ring cavities: recyclable and robust surface-enhanced Raman scattering substrates for signal detection from few molecules.

    PubMed

    Gopalakrishnan, Anisha; Chirumamilla, Manohar; De Angelis, Francesco; Toma, Andrea; Zaccaria, Remo Proietti; Krahne, Roman

    2014-08-26

    Top-down fabrication of electron-beam lithography (EBL)-defined metallic nanostructures is a successful route to obtain extremely high electromagnetic field enhancement via plasmonic effects in well-defined regions. To this aim, various geometries have been introduced such as disks, triangles, dimers, rings, self-similar lenses, and more. In particular, metallic dimers are highly efficient for surface-enhanced Raman spectroscopy (SERS), and their decoupling from the substrate in a three-dimensional design has proven to further improve their performance. However, the large fabrication time and cost has hindered EBL-defined structures from playing a role in practical applications. Here we present three-dimensional nanostar dimer devices that can be recycled via maskless metal etching and deposition processes, due to conservation of the nanostructure pattern in the 3D geometry of the underlying Si substrate. Furthermore, our 3D-nanostar-dimer-in-ring structures (3D-NSDiRs) incorporate several advantageous aspects for SERS by enhancing the performance of plasmonic dimers via an external ring cavity, by efficient decoupling from the substrate through an elevated 3D design, and by bimetallic AuAg layers that exploit the increased performance of Ag while maintaining the biocompatibility of Au. We demonstrate SERS detection on rhodamine and adenine at extremely low density up to the limit of few molecules and analyze the field enhancement of the 3D-NSDiRs with respect to the exciting wavelength and metal composition.

  5. High-resolution black-blood contrast-enhanced T1 weighted images for the diagnosis and follow-up of intracranial arteritis

    PubMed Central

    Saam, T; Habs, M; Pollatos, O; Cyran, C; Pfefferkorn, T; Dichgans, M; Dietrich, O; Glaser, C; Reiser, M F; Nikolauo, K

    2010-01-01

    Primary arteritis of the central nervous system (CNS) comprises a heterogeneous group of CNS disorders, which is characterised by non-atheromatous inflammation and necrosis of the arterial wall. The clinical presentation is highly variable, with stroke being the most common manifestation. Conventional angiography is considered to be the best imaging tool for diagnosing the disease. However, angiographic findings, which usually show lumen irregularities and stenosis, are often unspecific and can occur with a variety of other vascular disorders, such as atherosclerosis and arterial dissection. Therefore, brain biopsies are often needed to confirm the diagnosis. Recent reports have shown that MRI is able to visualise contrast enhancement in subjects with known primary CNS arteritis. PMID:20739338

  6. Intracranial hemangiopericytoma: study of 12 cases.

    PubMed

    Alén, J F; Lobato, R D; Gómez, P A; Boto, G R; Lagares, A; Ramos, A; Ricoy, J R

    2001-01-01

    Most hemangiopericytomas (HPCs) are located in the musculoskeletal system and the skin, while the intracranial location is rare. They represent 2 to 4% in large series of meningeal tumours, thus accounting for less than 1% of all intracranial tumours. Many authors have argued about the true origin of this tumour. The current World Health Organization classification of Central Nervous System tumours distinguishes HPC as an entity of its own, and classified it into the group of "mesenchymal, non-meningothelial tumours". Radical surgery is the treatment of choice, but must be completed with postoperative radiotherapy, which has proved to be the therapy most strongly related to the final prognosis. HPCs have a relentless tendency for local recurrence and metastases outside the central nervous system which can appear even many years after diagnosis and adequate treatment of the primary tumour. Twelve patients with intracranial HPC were treated at our Unit between 1978 and 1999. There were 10 women and 2 men. Ten tumours were supratentorial and most located at frontoparietal parasagittal level. The most common manner of presentation was a focal motor deficit. All tumours were hyperdense in the basal Computed Tomography scans and most enhanced homogeneously following intravenous contrast injection. In 50% of cases, tumour margins were irregular or lobulated. Seven tumours were studied with Magnetic Resonance Imaging, being six of them iso-intense with the cortical gray matter on T1-weighted and T2-weighted images. Twenty operations were performed in the 12 patients. In 10 cases radical excision could be achieved with no operative mortality. Total recurrence rate was 33.3%. Eight patients were treated with external radiotherapy at some time through the course of their disease. Eight out of the 12 patients in this series are disease-free (Glasgow Outcome Scale categories 1 and 2) after a mean follow up of 52 months. PMID:11534674

  7. Chemical Sensing Using Infrared Cavity Enhanced Spectroscopy: Short Wave Infrared Cavity Ring Down Spectroscopy (SWIR CRDS) Sensor

    SciTech Connect

    Williams, Richard M.; Harper, Warren W.; Aker, Pam M.; Thompson, Jason S.; Stewart, Timothy L.

    2003-10-01

    The principal goal of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project is to explore and develop the science and technology behind point and stand off infrared (IR) spectroscopic chemical sensors that are needed for detecting weapons proliferation activity and countering terrorism. Missions addressed include detecting chemical, biological, and nuclear weapons and their production; counter terrorism measures that involve screening luggage, personnel, and shipping containers for explosives, firearms, narcotics, chemical weapons and/or their residues; and mapping of contaminated areas. The science and technology developed in this program is dual use in that it additionally supports progress in a diverse set of agendas that include chemical weapons defense programs, air operations activities, emissions monitoring, law enforcement, and medical diagnostics. Sensors for these missions require extremely low limits of detection because many of the targeted signature species are either present in low concentrations or have extremely low vapor pressures. The sensors also need to be highly selective as the environments that they will be operated in will contain a variety of interferent species and false positive detection is not an option. PNNL has been working on developing a class of sensors that draw vapor into optical cavities and use laser-based spectroscopy to identify and quantify the vapor chemical content. The cavity enhanced spectroscopies (CES) afford extreme sensitivity, excellent selectivity, noise immunity, and rapid, real-time, in-situ chemical characterization. PNNL's CES program is currently focused on developing two types of sensors. The first one, which is based on cavity ring down spectroscopy (CRDS), uses short wave infrared (SWIR) lasers to interrogate species. The second sensor, which is based on noise immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE OHMS), uses long wave infrared (LWIR) quantum cascade

  8. CT and intracranial manifestations of otorhinologic disease.

    PubMed

    Keller, M A; Holgate, R C; McClarty, B M

    1982-12-01

    Most inflammatory and neoplastic diseases of the ear, nose, nasopharynx, and paranasal sinuses have the capability of intracranial extension. CT is extremely important in defining such lesions, and surpasses complex motion tomography in delineating the extracranial soft tissue involvement and intracranial spread. Trauma can simultaneously affect both intracranial and extracranial compartments but because of its scope, is not dealt with in this submission.

  9. Planetary rings

    SciTech Connect

    Greenberg, R.; Brahic, A.

    1984-01-01

    Among the topics discussed are the development history of planetary ring research, the view of planetary rings in astronomy and cosmology over the period 1600-1900, the characteristics of the ring systems of Saturn and Uranus, the ethereal rings of Jupiter and Saturn, dust-magnetosphere interactions, the effects of radiation forces on dust particles, the collisional interactions and physical nature of ring particles, transport effects due to particle erosion mechanisms, and collision-induced transport processes in planetary rings. Also discussed are planetary ring waves, ring particle dynamics in resonances, the dynamics of narrow rings, the origin and evolution of planetary rings, the solar nebula and planetary disk, future studies of the planetary rings by space probes, ground-based observatories and earth-orbiting satellites, and unsolved problems in planetary ring dynamics.

  10. Unruptured Intracranial Aneurysms:

    PubMed Central

    Raymond, J.; Nguyen, T.; Chagnon, M.; Gevry, G.

    2007-01-01

    'if a man will begin with certainties, he shall end in doubts; 'but if he will be content to begin with doubts he shall end in certainties'. Sir Francis Bacon, The Advancement of Learning Summary In the absence of level one evidence, the treatment of unruptured intracranial aneurysms is grounded on opinions. Results of the largest registry available, ISUIA (the International Study on Unruptured Intraacranial Aneurysms) suggest that surgical or endovascular treatments are rarely justified. Yet the unruptured aneurysm is the most frequent indication for treatment in many endovascular centres. In preparation for the initiation of a randomized trial, we aimed at a better knowledge of endovascular expert opinions on unruptured aneurysms. We administered a standard questionnaire to 175 endovascular experts gathered at the WFITN meeting in Val d'lsère in 2007. Four paradigm unruptured aneurysms were used to poll opinions on risks of treatment or observation, as well as on their willingness to treat, observe or propose to the patient participation in a randomized trial, using six questions for each aneurysm. Opinions varied widely among lesions and among participants. Most participants (92.5%) were consistent, as they would offer treatment only if their estimate of the ten-year risk of spontaneous hemorrhage would exceed risks of treatment. Estimates of the natural history were consistently higher than that reported by ISUIA. Conversely, treatment risks were underestimated compared to those reported in ISUIA, but within the range reported in a recent French registry (ATENA). Participants were more confident in their evaluation of treatment risks and in their skills at treating aneurysms than in their estimates of risks of rupture entailed by the presence of the lesion, the latter being anchored at or close to 1% /year. The gulf between expert opinions, clinical practices and available data from registries persist. Expert opinions are compatible with the primary hypothesis

  11. Smart multifunctional core-shell nanospheres with drug and gene co-loaded for enhancing the therapeutic effect in a rat intracranial tumor model

    NASA Astrophysics Data System (ADS)

    Wang, Hanjie; Su, Wenya; Wang, Sheng; Wang, Xiaomin; Liao, Zhenyu; Kang, Chunsheng; Han, Lei; Chang, Jin; Wang, Guangxiu; Pu, Peiyu

    2012-09-01

    Glioblastoma with high mortality has been one of the most serious cancers threatening human health. Because of the present treatment limitations, there is an urgent need to construct a multifunctional vesicle for enhancing the treatment of in situ malignant glioblastoma. In our study, drug and gene co-loaded magnetic PLGA/multifunctional polymeric liposome (magnetic PLGA/MPLs) core-shell nanospheres were constructed. They were mainly self-assembled from two parts: hydrophobic PLGA cores that can load drugs and magnetic nanocrystals; and polymeric lipid shells anchored with functional molecules such as PEG chains, TAT peptides and RGD peptides that can help the vectors to condense the gene, prolong the circulation time, cross the blood brain barrier and target delivery to the cancer tissue. The results showed that the magnetic PLGA/MPLs nanosphere has a nanosized core-shell structure, can achieve sustained drug release and has good DNA binding abilities. Importantly, compared with the control group and other groups with single functionality, it can co-deliver the drug and gene into the same cell in vitro and show the strongest inhibiting effect on the growth of the in situ malignant glioblastoma in vivo. All of these results indicated that the different functional components of magnetic PLGA/MPLs, can form an organic whole and none of them can be dispensed with. The magnetic PLGA/MPLs nanosphere may be another option for treatment of glioblastoma.Glioblastoma with high mortality has been one of the most serious cancers threatening human health. Because of the present treatment limitations, there is an urgent need to construct a multifunctional vesicle for enhancing the treatment of in situ malignant glioblastoma. In our study, drug and gene co-loaded magnetic PLGA/multifunctional polymeric liposome (magnetic PLGA/MPLs) core-shell nanospheres were constructed. They were mainly self-assembled from two parts: hydrophobic PLGA cores that can load drugs and magnetic

  12. Intracranial pressure and skull remodeling

    PubMed Central

    McCulley, Timothy J.; Jordan Piluek, W.; Chang, Jessica

    2014-01-01

    In this article we review bony changes resulting from alterations in intracranial pressure (ICP) and the implications for ophthalmologists and the patients for whom we care. Before addressing ophthalmic implications, we will begin with a brief overview of bone remodeling. Bony changes seen with chronic intracranial hypotension and hypertension will be discussed. The primary objective of this review was to bring attention to bony changes seen with chronic intracranial hypotension. Intracranial hypotension skull remodeling can result in enophthalmos. In advanced disease enophthalmos develops to a degree that is truly disfiguring. The most common finding for which subjects are referred is ocular surface disease, related to loss of contact between the eyelids and the cornea. Other abnormalities seen include abnormal ocular motility and optic atrophy. Recognition of such changes is important to allow for diagnosis and treatment prior to advanced clinical deterioration. Routine radiographic assessment of bony changes may allow for the identification of patient with abnormal ICP prior to the development of clinically significant disease. PMID:25859141

  13. Intracranial hypertension: classification and patterns of evolution

    PubMed Central

    Iencean, SM

    2008-01-01

    Intracranial hypertension (ICH) was systematized in four categories according to its aetiology and pathogenic mechanisms: parenchymatous ICH with an intrinsic cerebral cause; vascular ICH, which has its aetiology in disorders of cerebral blood circulation; ICH caused by disorders of cerebro–spinal fluid dynamics and idiopathic ICH. The increase of intracranial pressure is the first to happen and then intracranial hypertension develops from this initial effect becoming symptomatic; it then acquires its individuality, surpassing the initial disease. The intracranial hypertension syndrome corresponds to the stage at which the increased intracranial pressure can be compensated and the acute form of intracranial hypertension is equivalent to a decompensated ICH syndrome. The decompensation of intracranial hypertension is a condition of instability and appears when the normal intrinsic ratio of intracranial pressure – time fluctuation is changed. The essential conditions for decompensation of intracranial hypertension are: the speed of intracranial pressure increase over normal values, the highest value of abnormal intracranial pressure and the duration of high ICP values. Medical objectives are preventing ICP from exceeding 20 mm Hg and maintaining a normal cerebral blood flow. The emergency therapy is the same for the acute form but each of the four forms of ICH has a specific therapy, according to the pathogenic mechanism and if possible to aetiology. PMID:20108456

  14. Magnetic resonance imaging features of intracranial astrocytomas and oligodendrogliomas in dogs.

    PubMed

    Young, Benjamin D; Levine, Jonathan M; Porter, Brian F; Chen-Allen, Annie V; Rossmeisl, John H; Platt, Simon R; Kent, Marc; Fosgate, Geoffrey T; Schatzberg, Scott J

    2011-01-01

    Astrocytomas and oligodendrogliomas represent one third of histologically confirmed canine brain tumors. Our purpose was to describe the magnetic resonance (MR) imaging features of histologically confirmed canine intracranial astrocytomas and oligodendrogliomas and to examine for MR features that differentiate these tumor types. Thirty animals with confirmed astrocytoma (14) or oligodendroglioma (16) were studied. All oligodendrogliomas and 12 astrocytomas were located in the cerebrum or thalamus, with the remainder of astrocytomas in the cerebellum or caudal brainstem. Most (27/30) tumors were associated with both gray and white matter. The signal characteristics of both tumor types were hypointense on T1-weighted images (12 each) and hyperintense on T2-weighted images (11/14 astrocytomas, 12/16 oligodendrogliomas). For astrocytomas and oligodendrogliomas, respectively, common findings were contrast enhancement (10/13, 11/15), ring-like contrast enhancement (6/10, 9/11), cystic regions within the mass (7/14, 12/16), and hemorrhage (4/14, 6/16). Oligodendrogliomas were significantly more likely to contact the brain surface (meninges) than astrocytomas (14/16, 7/14, respectively, P=0.046). Contact with the lateral ventricle was the most common finding, occurring in 13/14 astrocytomas and 14/16 oligodendrogliomas. No MR features were identified that reliably distinguished between these two tumor types. Contrast enhancement was more common in high-grade tumors (III or IV) than low-grade tumors (II, P=0.008). PMID:21388463

  15. Treatment of Idiopathic Intracranial Hypotension With Tea: A Case Report

    PubMed Central

    Petramfar, Peyman; Mohammadi, S. Saeed; Hosseinzadeh, Farideh

    2016-01-01

    Introduction The syndrome of spontaneous intracranial hypotension has been increasingly diagnosed since its discovery through magnetic resonance imaging (MRI). It is a rare syndrome that is due to the leakage of cerebrospinal fluid (CSF) from a tear in the dura and can occur at any age, even among adolescents, but is most frequently seen among females in late middle age. Case Presentation Here, we describe a 32-year-old woman with a two-month history of headaches and occasional nausea and vomiting (N/V). MRI without gadolinium was normal, but meningeal enhancement was seen in MRI with gadolinium. The lumbar puncture revealed a low opening pressure. Computed tomography myelography (CT myelography) showed no leakage; Therefore, idiopathic intracranial hypotension was diagnosed. Treatment was started using tea, and the patient’s headache got significantly better in about a day. Conclusions Conservative therapy, such as bed rest and caffeine treatment with eight cups of tea daily, yielded a significant improvement in our patient. Effectively, the patient constitutes a case of idiopathic intracranial hypotension due to undetectable CSF leakage or hyper-absorption, with good response to conservative management through tea-drinking. Further investigations with an appropriate sample size are needed in order to confirm this intervention in the treatment of idiopathic intracranial hypotension. PMID:27621920

  16. Treatment of Idiopathic Intracranial Hypotension With Tea: A Case Report

    PubMed Central

    Petramfar, Peyman; Mohammadi, S. Saeed; Hosseinzadeh, Farideh

    2016-01-01

    Introduction The syndrome of spontaneous intracranial hypotension has been increasingly diagnosed since its discovery through magnetic resonance imaging (MRI). It is a rare syndrome that is due to the leakage of cerebrospinal fluid (CSF) from a tear in the dura and can occur at any age, even among adolescents, but is most frequently seen among females in late middle age. Case Presentation Here, we describe a 32-year-old woman with a two-month history of headaches and occasional nausea and vomiting (N/V). MRI without gadolinium was normal, but meningeal enhancement was seen in MRI with gadolinium. The lumbar puncture revealed a low opening pressure. Computed tomography myelography (CT myelography) showed no leakage; Therefore, idiopathic intracranial hypotension was diagnosed. Treatment was started using tea, and the patient’s headache got significantly better in about a day. Conclusions Conservative therapy, such as bed rest and caffeine treatment with eight cups of tea daily, yielded a significant improvement in our patient. Effectively, the patient constitutes a case of idiopathic intracranial hypotension due to undetectable CSF leakage or hyper-absorption, with good response to conservative management through tea-drinking. Further investigations with an appropriate sample size are needed in order to confirm this intervention in the treatment of idiopathic intracranial hypotension.

  17. Rapid virtual stenting for intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Chen, Danyang; Chen, Zihe; Wang, Xiangyu; Paliwal, Nikhil; Xiang, Jianping; Meng, Hui; Corso, Jason J.; Xu, Jinhui

    2016-03-01

    The rupture of Intracranial Aneurysms is the most severe form of stroke with high rates of mortality and disability. One of its primary treatments is to use stent or Flow Diverter to divert the blood flow away from the IA in a minimal invasive manner. To optimize such treatments, it is desirable to provide an automatic tool for virtual stenting before its actual implantation. In this paper, we propose a novel method, called ball-sweeping, for rapid virtual stenting. Our method sweeps a maximum inscribed sphere through the aneurysmal region of the vessel and directly generates a stent surface touching the vessel wall without needing to iteratively grow a deformable stent surface. Our resulting stent mesh has guaranteed smoothness and variable pore density to achieve an enhanced occlusion performance. Comparing to existing methods, our technique is computationally much more efficient.

  18. Primary intracranial choriocarcinoma: MR imaging findings.

    PubMed

    Lv, X-F; Qiu, Y-W; Zhang, X-L; Han, L-J; Qiu, S-J; Xiong, W; Wen, G; Zhang, Y-Z; Zhang, J

    2010-11-01

    PICCC is the rarest, most malignant primary intracranial GCT. The purpose of this study was to describe and characterize the MR imaging findings in a series of 7 patients (6 males and 1 female; mean age, 11.9 years) with pathologically proved PICCC in our institution from 2004 to 2009. All tumors were located within the pineal (n = 6) or suprasellar (n = 1) regions. On T2-weighted MR imaging, the lesions appeared markedly heterogeneous with areas of both hypointensity and hyperintensity reflecting the histologic heterogeneity, including hemorrhage, fibrosis, cysts, or necrosis. Heterogeneous (n = 7), ringlike (n = 4), and/or intratumoral nodular (n = 3) enhancement was noted on T1-weighted images with gadolinium. These MR imaging findings, combined with patient age and serum β-HCG levels, may prove helpful in distinguishing PICCC from the more common primary brain tumors, thereby avoiding biopsy of this highly vascular tumor. PMID:20616180

  19. Rapid Virtual Stenting for Intracranial Aneurysms

    PubMed Central

    Zhao, Liang; Chen, Danyang; Chen, Zihe; Wang, Xiangyu; Paliwal, Nikhil; Xiang, Jianping; Meng, Hui; Corso, Jason J.; Xu, Jinhui

    2016-01-01

    The rupture of Intracranial Aneurysms is the most severe form of stroke with high rates of mortality and disability. One of its primary treatments is to use stent or Flow Diverter to divert the blood flow away from the IA in a minimal invasive manner. To optimize such treatments, it is desirable to provide an automatic tool for virtual stenting before its actual implantation. In this paper, we propose a novel method, called ball-sweeping, for rapid virtual stenting. Our method sweeps a maximum inscribed sphere through the aneurysmal region of the vessel and directly generates a stent surface touching the vessel wall without needing to iteratively grow a deformable stent surface. Our resulting stent mesh has guaranteed smoothness and variable pore density to achieve an enhanced occlusion performance. Comparing to existing methods, our technique is computationally much more efficient. PMID:27346910

  20. High-resolution Magnetic Resonance Vessel Wall Imaging for Intracranial Arterial Stenosis

    PubMed Central

    Zhu, Xian-Jin; Wang, Wu; Liu, Zun-Jing

    2016-01-01

    Objective: To discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis. Date Sources: We retrieved information from PubMed database up to December 2015, using various search terms including vessel wall imaging (VWI), high-resolution magnetic resonance imaging, intracranial arterial stenosis, black blood, and intracranial atherosclerosis. Study Selection: We reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI. We organized this data to explain the value of VWI in clinical application. Results: VWI with black blood technique could provide high-quality images with submillimeter voxel size, and display both the vessel wall and lumen of intracranial artery simultaneously. Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening, enhancement, and vessel remodeling on VWI. This technique could be used for determining causes of stenosis, identification of stroke mechanism, risk-stratifying patients, and directing therapeutic management in clinical practice. In addition, a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy. Conclusions: This review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management. PMID:27231176

  1. Intracranial Rosai-Dorfman disease.

    PubMed

    Huang, Bo Yuan; Zong, Miao; Zong, Wen Jing; Sun, Yan Hui; Zhang, Hua; Zhang, Hong Bo

    2016-10-01

    Rosai-Dorfman disease (RDD) is a rare histioproliferative disorder that only occasionally involves the central nervous system. We present the diagnosis and treatment of five patients with intracranial RDD. The patients were preoperatively misdiagnosed as meningioma or eosinophilic granuloma. All five patients were treated by total or subtotal surgical resection and none of them experienced recurrence. Histopathological examination showed a characteristic emperipolesis, the lymphocytes were engulfed in the S-100 protein and CD68 positive histiocytes, with negative expression of CD1a. Preoperative diagnosis of intracranial RDD is still challenging because the lesion is usually a dural-based lesion that mimics a meningioma. Surgical resection is an effective treatment and radiotherapy, steroid and chemotherapy has not demonstrated reliable therapeutic efficiency. PMID:27561856

  2. Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  3. Planetary rings

    NASA Technical Reports Server (NTRS)

    Cook, A. F.

    1980-01-01

    Observations of the Rings of Saturn from the Pioneer spacecraft, discovery of the Ring of Jupiter, ground based polarimetry of the Rings of Saturn and some theoretical studies may be combined to markedly advance our understanding of the Rings of Jupiter, Saturn and Uranus. In particular, narrow rings can be self-gravitatingly stable inside Roche's limit and outside another closer limit. They can be created from a satellite which evolves across its Roche limit either by inward tidal drift or by growth of the planet by accretion. These considerations suggest that Neptune may well be surrounded by one or more narrow rings like those of Uranus.

  4. Clinical Analysis of Intracranial Hemangiopericytoma

    PubMed Central

    Park, Byoung-Joo; Hong, Yong-Kil; Jeun, Sin-Soo; Lee, Kwan-Sung; Lee, Youn-Soo

    2013-01-01

    Objective Intracranial hemangiopericytomas (HPCs) are rare tumors with aggressive behavior, including local recurrence and distant metastasis. We conducted this retrospective study to evaluate the efficacy of grossly total resection and adjuvant radiotherapy (RT) for these tumors. Methods A total of 13 patients treated for intracranial HPC from January 1995 through May 2013 were included in this retrospective study. We analyzed the clinical presentations, radiologic appearances, treatment results, and follow-up outcomes, as well as reviewed other studies. Results The ages of the patients at the time of diagnosis ranged from 26 to 73 years (mean : 48 years). The majority of the patients were male (92.3%), and the majority of the tumors were located in the parasagittal and falx. The ratio of intracranial HPCs to meningiomas was 13 : 598 in same period, or 2.2%. Seven patients (53.8%) had anaplastic HPCs. Nine patients (69.2%) underwent gross total tumor resection in the first operation without mortality. Eleven patients (84.6%) underwent postoperative adjuvant RT. Follow-up period ranged from 13 to 185 months (mean : 54.3 months). The local recurrence rate was 46.2% (6/13), and there were no distant metastases. The 10-year survival rate after initial surgery was 83.9%. The initial mean Karnofsky performance scale (KPS) was 70.8 and the final mean KPS was 64.6. Conclusion Gross total tumor resection upon initial surgery is very important. We believe that adjuvant RT is helpful even with maximal tumor resection. Molecular biologic analyses and chemotherapy studies are required to achieve better outcomes in recurrent intracranial HPCs. PMID:24294454

  5. Diagnosis of Intracranial Artery Dissection

    PubMed Central

    KANOTO, Masafumi; HOSOYA, Takaaki

    2016-01-01

    Cerebral arterial dissection is defined as a hematoma in the wall of a cervical or an intracranial artery. Cerebral arterial dissection causes arterial stenosis, occlusion, and aneurysm, resulting in acute infarction and hemorrhage. Image analysis by such methods as conventional angiography, computed tomography, magnetic resonance imaging, and so on plays an important role in diagnosing cerebral arterial dissection. In this study, we explore the methods and findings involved in the diagnosis of cerebral arterial dissection. PMID:27180630

  6. Patterns of contrast enhancement in the brain and meninges.

    PubMed

    Smirniotopoulos, James G; Murphy, Frances M; Rushing, Elizabeth J; Rees, John H; Schroeder, Jason W

    2007-01-01

    Contrast material enhancement for cross-sectional imaging has been used since the mid 1970s for computed tomography and the mid 1980s for magnetic resonance imaging. Knowledge of the patterns and mechanisms of contrast enhancement facilitate radiologic differential diagnosis. Brain and spinal cord enhancement is related to both intravascular and extravascular contrast material. Extraaxial enhancing lesions include primary neoplasms (meningioma), granulomatous disease (sarcoid), and metastases (which often manifest as mass lesions). Linear pachymeningeal (dura-arachnoid) enhancement occurs after surgery and with spontaneous intracranial hypotension. Leptomeningeal (pia-arachnoid) enhancement is present in meningitis and meningoencephalitis. Superficial gyral enhancement is seen after reperfusion in cerebral ischemia, during the healing phase of cerebral infarction, and with encephalitis. Nodular subcortical lesions are typical for hematogenous dissemination and may be neoplastic (metastases) or infectious (septic emboli). Deeper lesions may form rings or affect the ventricular margins. Ring enhancement that is smooth and thin is typical of an organizing abscess, whereas thick irregular rings suggest a necrotic neoplasm. Some low-grade neoplasms are "fluid-secreting," and they may form heterogeneously enhancing lesions with an incomplete ring sign as well as the classic "cyst-with-nodule" morphology. Demyelinating lesions, including both classic multiple sclerosis and tumefactive demyelination, may also create an open ring or incomplete ring sign. Thick and irregular periventricular enhancement is typical for primary central nervous system lymphoma. Thin enhancement of the ventricular margin occurs with infectious ependymitis. Understanding the classic patterns of lesion enhancement--and the radiologic-pathologic mechanisms that produce them--can improve image assessment and differential diagnosis.

  7. Neptune's rings

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  8. Vascular ring

    MedlinePlus

    ... with aberrant subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... accounts for less than 1% of all congenital heart problems. The condition occurs as often in males ...

  9. Prognostic significance of intracranial pressure monitoring and intracranial hypertension in severe brain trauma patients.

    PubMed

    Kostić, Aleksandar; Stefanović, Ivan; Novak, Vesna; Veselinović, Dragan; Ivanov, Goran; Veselinović, Aleksandar

    2011-01-01

    Since without prospective randomized studies it is not possible to have a clear attitude towards the importance of intracranial pressure monitoring, this study was aimed at examining the prognostic effect of the intracranial pressure monitoring and intracranial pressure oriented therapy in severe brain trauma patients, and at defining optimal intracranial pressure values for starting the treatment. Two groups of patients were treated in the study, one consisted of 32 patients undergoing intracranial pressure monitoring and the second group of 29 patients without intracranial pressure monitoring in the control group. The study was prospective with groups randomized. There were 53% survivals in the intracranial pressure monitored patients and 34% in the control group, with no significant difference in the survival rate between the two groups (chi2=2.11; p=0.15; p>0.05). The average intracranial pressure in the patients with intracranial hypertension who died was 27 mm Hg, while in the patients who survived the average intracranial pressure was significantly lower (Student's t test: t=2.91; p=0.008; p<0.01) and it was 18 mm Hg. We recommend starting intracranial pressure oriented therapy when the patient's intracranial pressure exceeds 18 mmHg during 2 hours of monitoring.

  10. Endoscopic treatment of transnasal intracranial penetrating foreign body.

    PubMed

    Lee, Dong Hoon; Seo, Bo Ra; Lim, Sang Chul

    2011-09-01

    Transnasal intracranial penetrating injury is rare. We report a case of transnasal intracranial penetrating metallic chopstick, which was removed successfully by endoscopic approach, and management of transnasal intracranial penetrating injuries.

  11. Intracranial hemorrhage due to intracranial hypertension caused by the superior vena cava syndrome.

    PubMed

    Bartek, Jiri; Abedi-Valugerdi, Golbarg; Liska, Jan; Nyström, Harriet; Andresen, Morten; Mathiesen, Tiit

    2013-07-01

    We report a patient with intracranial hemorrhage secondary to venous hypertension as a result of a giant aortic pseudoaneurysm that compressed the superior vena cava and caused obstruction of the venous return from the brain. To our knowledge, this is the first patient reported to have an intracranial hemorrhage secondary to a superior vena cava syndrome. The condition appears to be caused by a reversible transient rise in intracranial pressure, as a result of compression of the venous return from the brain. Treatment consisted of surgery for the aortic pseudoaneurysm, which led to normalization of the intracranial pressure and resorption of the intracranial hemorrhage.

  12. Second generation bisheteroarylpiperazine (BHAP) HIV-1 reverse transcriptasae inhibitors: Enhancement of antiviral activity and aqueous solubility via 5- and 6-substitution of the indole ring

    SciTech Connect

    Poel, T.; Thomas, R.C.; Romero, D.L.; Hosley, M.J.; Morge, R.A.; Biles, C.; Reusser, F.; Althaus, I.W.; Schinzer, W.C.; Platzer, D.J.

    1993-12-31

    U-87201E, a potent HIV-1 reverse transcriptase inhibitor (RTI) discovered at Upjohn, is currently in Phase II clinical trials. Additional structure-activity studies have identified second-generation BHAPs with enhanced antiviral activity and improved pharmaceutical properties, notably increased aqueous solubility. Capitalizing on initial SAR studies which demonstrated a tolerance for substitution in the indole ring, a series of BHAPs bearing 5- and 6-substituted indoles was evaluated. Substituents such as ethers, sulfonamides, ureas, and sulfamides containing water-solubilizing groups such as polyethers or basic amines provided highly potent BHAPs with greatly enhanced solubility, such as U-93923. The synthesis, antiviral evaluation and solubility properties of these potent HIV-1 RTIs will be detailed.

  13. Coexistence of Spinal Intramedullary Tuberculoma and Multiple Intracranial Tuberculomas.

    PubMed

    Lee, Dong-Yoon; Kim, Sang-Pyo; Kim, In-Soo

    2015-06-01

    Spinal intramedullary tuberculoma remains a very rare entity of central nervous system tuberculosis. This is the same with the coexistence of spinal intramedullary and intracranial tuberculomas that remains extremely rare with less than 20 cases reported at present. Authors describe this uncommon case by analyzing a 65-year-old female patient who had past history of kidney transplantation due to stage 5 chronic kidney disease and pulmonary tuberculosis on medication. The patient experiences progressive paraplegia and numbness on both lower extremities. Magnetic resonance imaging demonstrated an intramedullary mass at T9-10 level and multiple intracranial enhancing nodules. Microsurgical resection of spinal intramedullary mass was performed and the lesion was histopathologically confirmed as Mycobacterium tuberculosis. Efficient diagnosis and management of this rare disease are reviewed along with previously reported cases.

  14. Anesthetic considerations in intracranial aneurysm surgery.

    PubMed

    Steen, Stephen N; Johnson, Calvin; Lumb, Phillip D; Zelman, Vladimer; Mok, Martin S

    2002-03-01

    Rupture of an intracranial aneurysm generally has a poor outcome, though perioperative treatments have improved. At the present time, the important factors in the management of intracranial aneurysm surgery appear to be the maintenance of adequate cerebral perfusion pressure and the avoidance of hyperglycemia. Relevant features of the anesthetic management of this surgery are discussed.

  15. Intracranial subdural osteoma: a rare benign tumor that can be differentiated from other calcified intracranial lesions utilizing MR imaging.

    PubMed

    Barajas, Ramon F; Perry, Arie; Sughrue, Michael; Aghi, Manish; Cha, Soonmee

    2012-10-01

    We report the magnetic resonance (MR) imaging characteristics of subdural osteoma and other benign calcified intracranial lesions to highlight imaging features that differentiate between these disease entities. A 63-year-old woman presented with progressively altered mental status. Non-contrast CT demonstrated a densely calcified right middle cranial fossa extra-axial mass. MR imaging of the lesion demonstrated T1 and T2 hypointensity without evidence of contrast enhancement, parenchymal abnormality, or connection to adjacent venous structures. Diffusion weighted imaging demonstrated markedly decreased signal intensity and artificially reduced diffusion on apparent diffusion coefficient map. Histologically, the tumor was predominantly composed of lamellar bone and small fragments of residual dura consistent with subdural osteoma. This case demonstrates that radiological examination can provide additional insight into the origin of intracranial osteomas (extradural versus subdural versus sinonasal) and help distinguish from other diagnostic considerations including benign meningeal ossification and calcified meningioma prior to surgical resection.

  16. CO2 Effects in Space: Relationship to Intracranial Hypertension

    NASA Technical Reports Server (NTRS)

    Alexander, David J.

    2011-01-01

    This slide presentation reviews the effects of enhanced exposure to CO2 on Earth and in space. The effects of enhanced exposure to CO2 are experienced in almost all bodily systems. In space some of the effects are heightened due to the fluid shifts to the thorax and head. This fluid shift results in increased intracranial pressure, congested cerebral circulation, increased Cerebral Blood Flow (CBF) and Intravenous dilatation. The mechanism of the effect of CO2 on CBF is diagrammed, as is the Cerebrospinal Fluid (CSF) production. A listing of Neuroendocrine targets is included.

  17. Dabigatran-Associated Intracranial Hemorrhage

    PubMed Central

    Szarlej, Dorota K.; Rincon, Fred

    2015-01-01

    Dabigatran etexilate is an oral direct thrombin inhibitor approved for prevention of stroke and systemic embolization in patients with nonvalvular atrial fibrillation and for the treatment of venous thromboembolism. Although dabigatran has a favorable safety profile, predictable pharmacokinetics, fewer drug interactions than warfarin, and does not require monitoring, clinical data regarding dabigatran reversal are limited. In addition, currently available laboratory assays allow measurement of the presence, but not extent, of dabigatran-associated anticoagulation. Patient age, renal function, weight, concurrent drug therapy, adherence, and concomitant disease states can affect dabigatran’s efficacy and safety. Management of dabigatran-related intracranial hemorrhage must be approached on a case-by-case basis and include assessment of degree of anticoagulation, severity of hemorrhage, renal function, timing of last dabigatran dose, and risk of thromboembolic events. Initial management includes dabigatran discontinuation and general supportive measures. Oral activated charcoal should be administered in those who ingested dabigatran within 2 hours. Four-factor prothrombin complex concentrates (4PCCs), activated PCC, or recombinant activated factor VII use may be reasonable but is not evidence based. Reserve fresh frozen plasma for patients with dilutional coagulopathy. If readily available, hemodialysis should be considered, particularly in patients with advanced kidney injury or excessive risk of thromboembolic events. More clinical studies are needed to determine a standardized approach to treating dabigatran-associated intracranial hemorrhage. Institutional protocol development will facilitate safe, efficacious, and timely use of the limited management options. PMID:26425251

  18. Image-guided stereotactic centered craniotomy and laser resection of solid intracranial lesions.

    PubMed

    Zamorano, L; Dujovny, M; Chavantes, C; Malik, G; Ausman, J

    1990-01-01

    A technique in which solid intracranial lesions are removed using computerized image processing under stereotactic conditions is described. A specially developed carbon fiber ring holder compatible with most image studies is used as a reference system. Intraoperatively it affords freedom of patient positioning and unobstructed access to any site of the head. Four position alternatives of the aiming device allow the removal of lesions from any location. For superficial lesions located near eloquent areas, a 'centered' craniotomy is performed, usually under local anesthesia, and removal is performed using loupe magnification, bipolar coagulation ultrasonic aspiration of the Nd:YAG laser fiber in the contact or noncontact technique. In deep-seated lesions, a surgical 'corridor' is established and kept by means of retractors adapted for use with the stereotactic apparatus. Microsurgical techniques and the CO2 laser are used in solid lesions; in vascular lesions, bipolar coagulation or the ND:YAG laser can be used. Centered craniotomy allows the precise localization, enhancement, three-dimensional orientation and removal of lesions with minimal trauma to the surrounding brain. The technique has been applied in 78 cases where the extreme accuracy of the technique, benign postoperative course and short hospitalization have been impressive.

  19. Tuning the voices of a choir: Introducing a new tool to enhance the signals that are stored in tree-ring archives

    NASA Astrophysics Data System (ADS)

    Buras, Allan; van der Maaten, Ernst; Scharnweber, Tobias; Simard, Sonia; Heinrich, Ingo; Helle, Gerd; van der Maaten-Theunissen, Marieke; Eusemann, Pascal; Schnittler, Martin; Wilmking, Martin

    2015-04-01

    Tree-ring based archives, such as ring-width or density, are frequently used proxies for the reconstruction of past environmental parameters at annual resolution (e.g. Fritts, 1976). In terms of tree-ring width based reconstructions, ring-width measurements are usually acquired from several (often at least 20) trees growing under similar conditions (the 'choir') which are then averaged to a so-called master chronology (the 'voice'). Theoretically, this averaging evens out the individual-specific noises that act upon single trees. A statistical measure which frequently has been assumed to reflect the quality of tree-ring based reconstructions is the so-called expressed population signal (EPS, Wigley et al., 1984). Investigators have often sought to maximize EPS independent of individual tree reactions, but rather aiming at large sample sizes, which increase the value of EPS. Although studies have shown that the environmental signal of master chronologies may be enhanced in comparison with single trees (e.g. Carrer, 2011), ecological theory suggests that depending on particular site conditions (e.g. dry vs. wet sites) different trees within populations may react on different environmental drivers. In this context, recent studies have aimed at an individual selection of trees to form groups of similar growth responses (e.g. Piovesan et al., 2008, Walker and Johnstone, 2014). Grouping may help to lower the noise in the resulting averaged chronologies and therefore potentially enhance the strength of the targeted signal further. As a contribution to this particular topic, we present a new methodological approach - the Weighted Principal Component Analysis (WPCA), designed to identify variable growth responses in tree populations. To test its performance, we applied WPCA to various datasets which express different gradients of individual growth responses and compared WPCA to three other statistical approaches which have earlier been used in this context. For all tested

  20. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  1. PTFOS: Flexible and Absorbable Intracranial Electrodes for Magnetic Resonance Imaging

    PubMed Central

    Bonmassar, Giorgio; Fujimoto, Kyoko; Golby, Alexandra J.

    2012-01-01

    electrode/trace ink and had similar electrical properties to a standard subdural electrode set. The enhanced image quality could enable routine MRI exams of patients with intracranial electrode implantation and could also lead to chronic implantation solutions. PMID:22984396

  2. Coil Embolization for Intracranial Aneurysms

    PubMed Central

    2006-01-01

    Executive Summary Objective To determine the effectiveness and cost-effectiveness of coil embolization compared with surgical clipping to treat intracranial aneurysms. The Technology Endovascular coil embolization is a percutaneous approach to treat an intracranial aneurysm from within the blood vessel without the need of a craniotomy. In this procedure, a microcatheter is inserted into the femoral artery near the groin and navigated to the site of the aneurysm. Small helical platinum coils are deployed through the microcatheter to fill the aneurysm, and prevent it from further expansion and rupture. Health Canada has approved numerous types of coils and coil delivery systems to treat intracranial aneurysms. The most favoured are controlled detachable coils. Coil embolization may be used with other adjunct endovascular devices such as stents and balloons. Background Intracranial Aneurysms Intracranial aneurysms are the dilation or ballooning of part of a blood vessel in the brain. Intracranial aneurysms range in size from small (<12 mm in diameter) to large (12–25 mm), and to giant (>25 mm). There are 3 main types of aneurysms. Fusiform aneurysms involve the entire circumference of the artery; saccular aneurysms have outpouchings; and dissecting aneurysms have tears in the arterial wall. Berry aneurysms are saccular aneurysms with well-defined necks. Intracranial aneurysms may occur in any blood vessel of the brain; however, they are most commonly found at the branch points of large arteries that form the circle of Willis at the base of the brain. In 85% to 95% of patients, they are found in the anterior circulation. Aneurysms in the posterior circulation are less frequent, and are more difficult to treat surgically due to inaccessibility. Most intracranial aneurysms are small and asymptomatic. Large aneurysms may have a mass effect, causing compression on the brain and cranial nerves and neurological deficits. When an intracranial aneurysm ruptures and bleeds

  3. Rare extracranial localization of primary intracranial neoplasm

    PubMed Central

    Arndt, Susan; Wiech, Thorsten; Mader, Irina; Aschendorff, Antje; Maier, Wolfgang

    2008-01-01

    Meningioma, craniopharyngeoma and glioma are mainly intracranial lesions. Nevertheless, in rare cases these entities may occur solely as extracranial lesions that may present as intranasal/sinusoidal masses, with headaches and nasal obstruction. We present three cases of common intracranial tumors, with purely extracranial extension. The three described cases demonstrate, that preoperative MRI and CT imaging is important for differential diagnosis to exclude intracranial connections of the tumors. A definitive diagnosis requires specialized immunohistochemical examinations. In all cases of intranasal or pharyngeal neoplasm the diagnosis of meningioma, craniopharyngeoma and glioma should be considered as differential diagnosis to optimize the surgical procedure. PMID:18416840

  4. Modification of a commercial cavity ring-down spectroscopy NO{sub 2} detector for enhanced sensitivity

    SciTech Connect

    Castellanos, Patricia; Ehrman, Sheryl H.; Luke, Winston T.; Kelley, Paul; Stehr, Jeffrey W.; Dickerson, Russell R.

    2009-11-15

    Nitrogen dioxide (NO{sub 2}) plays a central role in atmospheric chemistry, air pollution, and biogeochemical cycles. Many analytical techniques have been developed to detect NO{sub 2}, but only chemiluminescence-based instruments are commonly, commercially available. There remains a need for a fast, light, and simple method to directly measure NO{sub 2}. In this work we describe the modification and characterization of a small, commercially available cavity ring-down spectroscopy (CRDS) NO{sub 2} detector suitable for surface and aircraft monitoring. A metal oxide scrubber was added to remove NO{sub 2}, and provide a chemical zero, improving the detection limit (3{sigma} of the background noise) from several parts per billion by volume (ppbv) to 0.06 ppbv, integrated over 60 s. Known interferences by water and particles were removed using Nafion tubing and a 1 {mu}m Teflon filter, respectively. A 95% response time of 18{+-}1 s was observed for a step change in concentration. The CRDS detector was run in parallel to an ozone chemiluminescence device with photolytic conversion of NO{sub 2} to NO. The two instruments measured ambient air in suburban Maryland. A least-squares fit to the comparison data resulted a slope of 0.960{+-}0.002 and R of 0.995, showing agreement within experimental uncertainty.

  5. Enhancing production of a 24-membered ring macrolide compound by a marine bacterium using response surface methodology*

    PubMed Central

    Chen, Hua; Wu, Mian-bin; Chen, Zheng-jie; Wang, Ming-lu; Lin, Jian-ping; Yang, Li-rong

    2013-01-01

    A 24-membered ring macrolide compound, macrolactin A has potential applications in pharmaceuticals for its anti-infectious and antiviral activity. In this study, macrolactin A was produced by a marine bacterium, which was identified as Bacillus subtilis by 16S ribosomal RNA (rRNA) sequence analysis. Electrospray ionization mass spectrometry (ESI/MS) and nuclear magnetic resonance (NMR) spectroscopy analyses were used to characterize this compound. To improve the production, response surface methodology (RSM) involving Box-Behnken design (BBD) was employed. Faeces bombycis, the main by-product in sericulture, was used as a nitrogen source in fermentation. The interactions between three significant factors, F. bombycis, soluble starch, and (NH4)2SO4 were investigated. A quadratic model was constructed to fit the production and the factors. Optimum medium composition was obtained by analysis of the model. When cultivated in the optimum medium, the production of macrolactin A was increased to 851 mg/L, 2.7 times as compared to the original. This study is also useful to find another way in utilizing F. bombycis. PMID:23549852

  6. [Radiotherapy of benign intracranial tumors].

    PubMed

    Delannes, M; Latorzeff, I; Chand, M E; Huchet, A; Dupin, C; Colin, P

    2016-09-01

    Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects. PMID:27523417

  7. [Non-contrast time-resolved magnetic resonance angiography combining high resolution multiple phase echo planar imaging based signal targeting and alternating radiofrequency contrast inherent inflow enhanced multi phase angiography combining spatial resolution echo planar imaging based signal targeting and alternating radiofrequency in intracranial arteries].

    PubMed

    Nakamura, Masanobu; Yoneyama, Masami; Tabuchi, Takashi; Takemura, Atsushi; Obara, Makoto; Sawano, Seishi

    2012-01-01

    Detailed information on anatomy and hemodynamics in cerebrovascular disorders such as AVM and Moyamoya disease is mandatory for defined diagnosis and treatment planning. Arterial spin labeling technique has come to be applied to magnetic resonance angiography (MRA) and perfusion imaging in recent years. However, those non-contrast techniques are mostly limited to single frame images. Recently we have proposed a non-contrast time-resolved MRA technique termed contrast inherent inflow enhanced multi phase angiography combining spatial resolution echo planar imaging based signal targeting and alternating radiofrequency (CINEMA-STAR). CINEMA-STAR can extract the blood flow in the major intracranial arteries at an interval of 70 ms and thus permits us to observe vascular construction in full by preparing MIP images of axial acquisitions with high spatial resolution. This preliminary study demonstrates the usefulness of the CINEMA-STAR technique in evaluating the cerebral vasculature.

  8. Management of raised intracranial pressure.

    PubMed

    Pickard, J D; Czosnyka, M

    1993-08-01

    This review has been written at an unfortunate time. Novel questions are being asked of the old therapies and there is an abundance of new strategies both to lower ICP and protect the brain against cerebral ischaemia. In the United Kingdom, the problem is to ensure that appropriate patients continue to be referred to centres where clinical trials of high quality can be undertaken. One of the success stories of the past decade has been the decline in the number of road accidents as a result of seat belt legislation, improvements in car design and the drink/driving laws. Hence, fortunately there are fewer patients with head injuries to treat and it is even more important that patients are appropriately referred if studies to assess efficacy of the new strategies are not to be thwarted. The nihilistic concept that intensive investigation with ICP monitoring for patients with diffuse head injury or brain swelling following evacuation of a haematoma or a contusion has no proven beneficial effect on outcome, requires revision. A cocktail of therapies may be required that can be created only when patients are monitored in sufficient detail to reveal the mechanisms underlying their individual ICP problem. Ethical problems may arise over how aggressively therapy for intracranial hypertension should be pursued and for how long. There has always been the concern that cranial decompression or prolonged barbiturate coma may preserve patients but with unacceptably severe disability. Some patients may be salvaged from herniating with massive cerebral infarction with the use of osmotherapy but is the outcome acceptable? Similar considerations apply to some children with metabolic encephalopathies. Where such considerations have been scrutinised in patients with severe head injury, the whole spectrum of outcomes appears to be shifted so that the number of severe disabilities and persistent vegetative states are not increased. However, it is important to be sensitive to such issues

  9. An intracranial malignant solitary fibrous tumor.

    PubMed

    Choi, Chan-Young; Han, Seong-Rok; Yee, Gi-Taek; Joo, Mee

    2011-04-01

    Intracranial malignant solitary fibrous tumor (SFT) is very rare. It was identified in a 39-year-old female patient who underwent malignant transformation over 6 months. MRI revealed an 8 × 5 × 6 cm mass with heterogenous strong enhancement in the left occipital lobe. Histologic findings and immunophenotype (positive for CD34, bcl-2 and vimentin, and negative for epithelial membrane antigen or S100 protein) of the primary tumor were typical of SFT. However, there was a focal area (<10% of tumor volume) showing hypercellularity, nuclear pleomorphism and increased Ki-67 labeling index (LI) of 10% (average, 1%). At the second operation, the recurrent tumor revealed full-blown histologic features of malignant SFT, such as infiltrative brain invasion, marked nuclear pleomorphism, frequent mitotic figures (15/10 high power fields), and high Ki-67 LI (25%). The presence of atypical histologic finding or increased Ki-67 LI in the typical SFT, although it is focal, needs to be mentioned in the diagnosis and also may require more aggressive surgical management.

  10. Remotely-powered intracranial pressure monitor

    NASA Technical Reports Server (NTRS)

    Fryer, T. B.

    1979-01-01

    Implantable RF powered monitor uses capacitive transducer and stiff metal diaphragm that gives high stability for long term intracranial pressure monitoring. Design of monitor reduces risk of infection while improving patient comfort and mobility.

  11. Intracranial complications of transorbital stab wounds.

    PubMed Central

    De Villiers, J C; Sevel, D

    1975-01-01

    Oscular and orbital injuries due to stab wounds may mask underlying serious intracranial damage. The correct clinical assessment and treatment of such cases require the attention of a team comprising a neurosurgeon, ophthalmologist, otolaryngologist, and plastic surgeon. Images PMID:1125159

  12. Uranus rings and two moons

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Voyager 2 has discovered two 'shepherd' satellites associated with the rings of Uranus. The two moons -- designated 1986U7 and 1986U8 -- are seen here on either side of the bright epsilon ring; all nine of the known Uranian rings are visible. The image was taken Jan. 21, 1986, at a distance of 4.1 million kilometers (2.5 million miles) and resolution of about 36 km (22 mi). The image was processed to enhance narrow features. The epsilon ring appears surrounded by a dark halo as a result of this processing; occasional blips seen on the ring are also artifacts. Lying inward from the epsilon ring are the delta, gamma and eta rings; then the beta and alpha rings; and finally the barely visible 4, 5 and 6 rings. The rings have been studied since their discovery in 1977, through observations of how they diminish the light of stars they pass in front of. This image is the first direct observation of all nine rings in reflected sunlight. They range in width from about 100 km (60 mi) at the widest part of the epsilon ring to only a few kilometers for most of the others. The discovery of the two ring moons 1986U7 and 1986U8 is a major advance in our understanding of the structure of the Uranian rings and is in good agreement with theoretical predictions of how these narrow rings are kept from spreading out. Based on likely surface brightness properties, the moons are of roughly 2O- and 3O-km diameter, respectively. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  13. Evaluation of Image-Guided Positioning for Frameless Intracranial Radiosurgery

    SciTech Connect

    Lamba, Michael Breneman, John C.; Warnick, Ronald E.

    2009-07-01

    Purpose: The standard for target alignment and immobilization in intracranial radiosurgery is frame-based alignment and rigid immobilization using a stereotactic head ring. Recent improvements in image-guidance systems have introduced the possibility of image-guided radiosurgery with nonrigid immobilization. We present data on the alignment accuracy and patient stability of a frameless image-guided system. Methods and Materials: Isocenter alignment errors were measured for in vitro studies in an anthropomorphic phantom for both frame-based stereotactic and frameless image-guided alignment. Subsequently, in vivo studies assessed differences between frame-based and image-guided alignment in patients who underwent frame-based intracranial radiosurgery. Finally, intratreatment target stability was determined by image-guided alignment performed before and after image-guided mask immobilized radiosurgery. Results: In vitro hidden target localization errors were comparable for the framed (0.7 {+-} 0.5 mm) and image-guided (0.6 {+-} 0.2 mm) techniques. The in vivo differences in alignment were 0.9 {+-} 0.5 mm (anteroposterior), -0.2 {+-} 0.4 mm (superoinferior), and 0.3 {+-} 0.5 mm (lateral). For in vivo stability tests, the mean distance differed between the pre- and post-treatment positions with mask-immobilized radiosurgery by 0.5 {+-} 0.3 mm. Conclusion: Frame-based and image-guided alignment accuracy in vitro was comparable for the system tested. In vivo tests showed a consistent trend in the difference of alignment in the anteroposterior direction, possibly due to torque to the ring and mounting system with frame-based localization. The mask system as used appeared adequate for patient immobilization.

  14. [Experience using intracranial endoscopy in neurologic traumatology].

    PubMed

    Karakhan, V B

    1988-03-01

    The endoscopic anatomy of the subdural space structure and endoscopic semiotics of intracranial lesions are presented. The direct vision of the lesion substrate outside projection of a small trepanation opening raised the reliability of diagnosis, provides a wide and atraumatic access for the removal of spreaded hematomas and other foci, allows surgery to be fulfilled even in critical patients. The application of intracranial endoscopy in neurotraumatology is considered as a technical principle.

  15. Time trends in intracranial bleeding associated with direct oral anticoagulants: a 5-year cohort study

    PubMed Central

    Hogg, Kerstin; Bahl, Bharat; Latrous, Meriem; Scaffidi Argentina, Sarina; Thompson, Jesse; Chatha, Aasil Ayyaz; Castellucci, Lana; Stiell, Ian G.

    2015-01-01

    Background: Over the past 5 years, dabigatran, rivaroxaban and apixaban were approved for stroke prevention. Phase III studies have shown a lower risk of intracranial bleeding with these direct oral anticoagulants than with warfarin; however, there is a lack of real-life data to validate this. We analyzed time trends in atraumatic intracranial bleeding from 2009 to 2013 among patients prescribed oral anticoagulants and those not prescribed oral anticoagulants. Methods: We used ICD-10-CA (enhanced Canadian version of the 10th revision of the International Statistical Classification of Diseases and Related Health Problems) codes to identify all patients with atraumatic intracranial bleeding who presented to our neurosurgical centre (serving a population of more than 1.2 million). Trained researchers extracted data on anticoagulant medications used in the week before diagnosis of the intracranial bleed. Provincial prescription data for oral anticoagulants were obtained from IMS Brogan CompuScript Market Dynamics. The primary outcome was the time trend in incident intracranial bleeds associated with oral anticoagulation during the period 2009-2013. The secondary outcomes were the time trend in intracranial bleeds not associated with oral anticoagulation and the provincial prescribing patterns for oral anticoagulants during the same period. Results: A total of 2050 patients presented with atraumatic intracranial bleeds during the study period. Of the 371 (18%) prescribed an anticoagulant in the week before presentation, 335 were prescribed an oral anticoagulant. There was an increasing time trend in intracranial bleeding associated with oral anticoagulants (p = 0.009; 6 additional events per year) and in intracranial bleeding not associated with oral anticoagulation (p = 0.06). During 2013, prescriptions for warfarin decreased to 70% of all oral anticoagulant prescriptions in the province, whereas those for dabigatran and rivaroxaban increased to 17% and 12

  16. Intracranial Rhabdomyoma: Case Report and Review of the Literature

    PubMed Central

    Santiago-Dieppa, David R; Zhou, Tianzan; Jones, Karra A; Chen, James Y; Hansen, Lawrence; U, Hoi Sang

    2016-01-01

    A 24-year-old male presented with eight months of increasingly severe frontal headaches, decreased right facial sensation, and periodic vertigo. Magnetic resonance imaging demonstrated a heterogeneously contrast-enhancing mass involving and expanding the right foramen ovale.  A biopsy of the lesion was performed, and the final pathologic diagnosis revealed a neoplastic rhabdomyoma. To date, only five cases of intracranial rhabdomyoma have been reported, and a rhabdomyoma involving the trigeminal nerve has never been described in an adult. This manuscript reviews the available literature and highlights the clinical, imaging, pathologic characteristics, and surgical management of these exceedingly rare lesions. PMID:27335706

  17. Computed tomographic spectrum of intracranial mycosis: correlation with histopathology

    SciTech Connect

    Whelan, M.A.; Stern, J.; deNapoli, R.A.

    1981-12-01

    Four cases of intracerebral fungal infection are reviewed. The clinical course is outlined, and the computed tomographic (CT) characteristics are analyzed in light of known pathological data. The CT appearance of intracranial mycosis is dependent on the type of fungus as well as the dominant infecting form, i.e., yeast or hyphae. The hyphal form leads predominantly to a CT pattern consistent with vascular occlusion and secondary abscess formation; the yeast form generally results in noncaseating granulomas, which appear on CT scan as nodular enhancing lesions. If the patient survives the acute infective process, these fungal lesions undergo a prolonged subacute phase, and may eventually calcify.

  18. Jupiter's ring

    NASA Technical Reports Server (NTRS)

    1979-01-01

    First evidence of a ring around the planet Jupiter is seen in this photograph taken by Voyager 1 on March 4, 1979. The multiple exposure of the extremely thin faint ring appears as a broad light band crossing the center of the picture. The edge of the ring is 1,212,000 km from the spacecraft and 57,000 km from the visible cloud deck of Jupiter. The background stars look like broken hair pins because of spacecraft motion during the 11 minute 12 second exposure. The wavy motion of the star trails is due to the ultra-slow natural oscillation of the spacecraft (with a period of 78 seconds). The black dots are geometric calibration points in the camera. The ring thickness is estimated to be 30 km or less. The photograph was part of a sequence planned to search for such rings in Jupiter's equatorial plane. The ring has been invisible from Earth because of its thinness and its transparency when viewed at any angle except straight on. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

  19. A season in Saturn's rings: Cycling, recycling and ring history

    NASA Astrophysics Data System (ADS)

    Esposito, L. W.; Meinke, B. K.; Albers, N.; Sremcevic, M.

    2012-04-01

    Cassini experiments have watched Saturn's ring system evolve before our eyes. Images and occultations show changes and transient events. The rings are a dynamic and complex geophysical system, incompletely modeled as a single-phase fluid. Key Cassini observations: High resolution images show straw, propellers, embedded moonlets, and F ring objects. Multiple UVIS, RSS and VIMS occutlations indicate multimodal ringlet and edge structure, including free and forced modes along with stochastic perturbations that are most likely caused by nearby mass concentrations. Vertical excursions are evident at ring edges and in other perturbed regions. The rings are occasionally hit by meteorites that leave a signature that may last centuries; meteoritic dust pollutes the rings. Temperature, reflectance and transmission spectra are influenced by the dynamical state of the ring particles. Saturn's Equinox 2009: Oblique lighting exposed vertical structure and embedded objects. The rings were the coldest ever. Images inspired new occultation and spectral analysis that show abundant structure in the perturbed regions. The rings are more variable and complex than we had expected prior to this seasonal viewing geometry. Sub-kilometer structure in power spectral analysis: Wavelet analysis shows features in the strongest density waves and at the shepherded outer edge of the B ring. Edges are variable as shown by multiple occultations and occultations of double stars. F ring kittens: 25 features seen in the first 102 occultations show a weak correlation with Prometheus location. We interpret these features as temporary aggregations. Simulation results indicate that accretion must be enhanced to match the kittens' size distribution. Images show that Prometheus triggers the formation of transient objects. Propellers and ghosts: Occulations and images provide evidence for small moonlets in the A, B and C rings. These indicate accretion occurs inside the classical Roche limit. Implications

  20. Flow Diverters for Intracranial Aneurysms

    PubMed Central

    Alderazi, Yazan J.; Kass-Hout, Tareq; Prestigiacomo, Charles J.; Gandhi, Chirag D.

    2014-01-01

    Flow diverters (pipeline embolization device, Silk flow diverter, and Surpass flow diverter) have been developed to treat intracranial aneurysms. These endovascular devices are placed within the parent artery rather than the aneurysm sac. They take advantage of altering hemodynamics at the aneurysm/parent vessel interface, resulting in gradual thrombosis of the aneurysm occurring over time. Subsequent inflammatory response, healing, and endothelial growth shrink the aneurysm and reconstruct the parent artery lumen while preserving perforators and side branches in most cases. Flow diverters have already allowed treatment of previously untreatable wide neck and giant aneurysms. There are risks with flow diverters including in-stent thrombosis, perianeurysmal edema, distant and delayed hemorrhages, and perforator occlusions. Comparative efficacy and safety against other therapies are being studied in ongoing trials. Antiplatelet therapy is mandatory with flow diverters, which has highlighted the need for better evidence for monitoring and tailoring antiplatelet therapy. In this paper we review the devices, their uses, associated complications, evidence base, and ongoing studies. PMID:24967131

  1. Intracranial Vasospasm without Intracranial Hemorrhage due to Acute Spontaneous Spinal Subdural Hematoma

    PubMed Central

    Oh, Jung-Hwan; Jwa, Seung-Joo; Yang, Tae Ki; Lee, Chang Sub; Oh, Kyungmi

    2015-01-01

    Spontaneous spinal subdural hematoma (SDH) is very rare. Furthermore, intracranial vasospasm (ICVS) associated with spinal hemorrhage has been very rarely reported. We present an ICVS case without intracranial hemorrhage following SDH. A 41-year-old woman was admitted to our hospital with a complaint of severe headache. Multiple intracranial vasospasms were noted on a brain CT angiogram and transfemoral cerebral angiography. However, intracranial hemorrhage was not revealed by brain MRI or CT. On day 3 after admission, weakness of both legs and urinary incontinence developed. Spine MRI showed C7~T6 spinal cord compression due to hyperacute stage of SDH. After hematoma evacuation, her symptoms gradually improved. We suggest that spinal cord evaluation should be considered in patients with headache who have ICVS, although intracranial hemorrhage would not be visible in brain images. PMID:26713084

  2. Simultaneous Spinal and Intracranial Chronic Subdural Hematoma Cured by Craniotomy and Laminectomy: A Video Case Report.

    PubMed

    Kanamaru, Hideki; Kanamaru, Kenji; Araki, Tomohiro; Hamada, Kazuhide

    2016-01-01

    Simultaneous spinal and intracranial chronic subdural hematoma (CSDH) is a rare entity. A 67-year-old man visited our hospital due to headache after diving into a river 2 weeks before. Non-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed bilateral intracranial CSDH. The bilateral CSDH was evacuated and his symptoms improved. Three days after craniotomy, he complained of sensory disturbance on his buttocks. Lumbar MRI showed a space-occupying lesion behind the thecal sac at L5. CT with myelography showed a subdural mass lesion; there was no communication with the subarachnoid space. Fourteen days after craniotomy, L5 laminectomy was performed and the dura mater was incised carefully. The video shows that a liquid hematoma similar to the intracranial CSDH flowed out, followed by cerebrospinal fluid. His symptoms improved after the operation and the hematoma did not recur. This is a rare condition of spinal CSDH demonstrated by neuroimaging and intraoperative video. PMID:27194987

  3. Ghostly Ring

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for poster version

    This image shows a ghostly ring extending seven light-years across around the corpse of a massive star. The collapsed star, called a magnetar, is located at the exact center of this image. NASA's Spitzer Space Telescope imaged the mysterious ring around magnetar SGR 1900+14 in infrared light. The magnetar itself is not visible in this image, as it has not been detected at infrared wavelengths (it has been seen in X-ray light).

    Magnetars are formed when a massive giant star ends its life in a supernova explosion, leaving behind a super dense neutron star with an incredibly strong magnetic field. The ring seen by Spitzer could not have formed during the original explosion, as any material as close to the star as the ring would have been disrupted by the supernova shock wave. Scientists suspect that the ring my actually be the edges of a bubble that was hollowed out by an explosive burst from the magnetar in 1998. The very bright region near the center of the image is a cluster of young stars, which may be illuminating the inner edge of the bubble, making it look like a ring in projection.

    This composite image was taken using all three of Spitzer's science instruments. The blue color represents 8-micron infrared light taken by the infrared array camera, green is 16-micron light from the infrared spectograph, and red is 24-micron radiation from the multiband imaging photometer.

  4. Hyperprolactinemia due to spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Nuño, Miriam; Rozen, Todd D; Maya, M Marcel; Mamelak, Adam N; Carmichael, John; Bonert, Vivien S

    2015-05-01

    OBJECT Spontaneous intracranial hypotension is an increasingly recognized cause of headaches. Pituitary enlargement and brain sagging are common findings on MRI in patients with this disorder. The authors therefore investigated pituitary function in patients with spontaneous intracranial hypotension. METHODS Pituitary hormones were measured in a group of 42 consecutive patients with spontaneous intracranial hypotension. For patients with hyperprolactinemia, prolactin levels also were measured following treatment. Magnetic resonance imaging was performed prior to and following treatment. RESULTS The study group consisted of 27 women and 15 men with a mean age at onset of symptoms of 52.2 ± 10.7 years (mean ± SD; range 17-72 years). Hyperprolactinemia was detected in 10 patients (24%), ranging from 16 ng/ml to 96.6 ng/ml in men (normal range 3-14.7 ng/ml) and from 31.3 ng/ml to 102.5 ng/ml in women (normal range 3.8-23.2 ng/ml). In a multivariate analysis, only brain sagging on MRI was associated with hyperprolactinemia. Brain sagging was present in 60% of patients with hyperprolactinemia and in 19% of patients with normal prolactin levels (p = 0.02). Following successful treatment of the spontaneous intracranial hypotension, hyperprolactinemia resolved, along with normalization of brain MRI findings in all 10 patients. CONCLUSIONS Spontaneous intracranial hypotension is a previously undescribed cause of hyperprolactinemia. Brain sagging causing distortion of the pituitary stalk (stalk effect) may be responsible for the hyperprolactinemia. PMID:25380110

  5. Primary Stenting of Intracranial Atherosclerotic Stenoses

    SciTech Connect

    Straube, T. Stingele, Robert; Jansen, Olav

    2005-04-15

    Purpose: To determine the feasibility and safety of stenting intracranial atherosclerotic stenoses.Methods: In 12 patients the results of primary intracranial stenting were evaluated retrospectively. Patient ages ranged from 49 to 79 years (mean 64 years). Six patients presented with stenoses in the anterior circulation, and six had stenosis in the posterior circulation. One patient presented with extra- and intracranial tandem stenosis of the left internal carotid artery. Three patients presented with acute basilar thrombosis, caused by high-grade basilar stenoses.Results: Intracranial stenoses were successfully stented in 11 of 12 patients. In one patient the stent could not be advanced over the carotid siphon to reach the stenosis of the ophthalmic internal carotid artery. Follow-up digital subtraction angiographic studies were obtained in two patients who had presented with new neurologic signs or symptoms. In both cases the angiogram did not show any relevant stenotic endothelial hyperplasia. In one patient, after local thrombolysis the stenosis turned out to be so narrow that balloon angioplasty had to be performed before stent deployment. All three patients treated for stenosis-related basilar thrombosis died due to brainstem infarction that had ensued before the intervention.Conclusions: Prophylactic primary stenting of intracranial stenoses of the anterior or posterior cerebral circulation can be performed with a low complication rate; technical problems such as stent flexibility must still be solved. Local thrombolysis followed by stenting in stenosis-related thrombotic occlusion is technically possible.

  6. Mechanistic Insight into the Superoxide Induced Ring Opening in Propylene Carbonate Based Electrolytes using in Situ Surface-Enhanced Infrared Spectroscopy.

    PubMed

    Vivek, J Padmanabhan; Berry, Neil; Papageorgiou, Georgios; Nichols, Richard J; Hardwick, Laurence J

    2016-03-23

    Understanding the mechanistic details of the superoxide induced solvent degradation, is important in the development of stable electrolytes for lithium-oxygen (Li-O2) batteries. Propylene carbonate (PC) decomposition on a model electrode surface is studied here using in situ attenuated total reflectance surface enhanced infrared absorption spectroscopy (ATR-SEIRAS). The sensitivity of the SEIRAS technique to the interfacial region allows investigation of subtle changes in the interface region during electrochemical reactions. Our SEIRAS studies show that the superoxide induced ring opening reaction of PC is determined by the electrolyte cation. Computational modeling of the proposed reaction pathway of superoxide with PC revealed a large difference in the activation energy barriers when Li(+) was the countercation compared with tetraethylammonium (TEA(+)), due to the coordination of Li(+) to the carbonate functionality. While the degradation of cyclic organic carbonates during the Li-O2 battery discharge process is a well-established case, understanding these details are of significant importance toward a rational selection of the Li-O2 battery electrolytes; our work signifies the use of SEIRAS technique in this direction. PMID:26909538

  7. Amino-Functionalized Multiwalled Carbon Nanotubes Lead to Successful Ring-Opening Polymerization of Poly(ε-caprolactone): Enhanced Interfacial Bonding and Optimized Mechanical Properties.

    PubMed

    Roumeli, Eleftheria; Papageorgiou, Dimitrios G; Tsanaktsis, Vasilios; Terzopoulou, Zoe; Chrissafis, Konstantinos; Avgeropoulos, Apostolos; Bikiaris, Dimitrios N

    2015-06-01

    In this work, the synthesis, structural characteristics, interfacial bonding, and mechanical properties of poly(ε-caprolactone) (PCL) nanocomposites with small amounts (0.5, 1.0, and 2.5 wt %) of amino-functionalized multiwalled carbon nanotubes (f-MWCNTs) prepared by ring-opening polymerization (ROP) are reported. This method allows the creation of a covalent-bonding zone on the surface of nanotubes, which leads to efficient debundling and therefore satisfactory dispersion and effective load transfer in the nanocomposites. The high covalent grafting extent combined with the higher crystallinity provide the basis for a significant enhancement of the mechanical properties, which was detected in the composites with up to 1 wt % f-MWCNTs. Increasing filler concentration encourages intrinsic aggregation forces, which allow only minor grafting efficiency and poorer dispersion and hence inferior mechanical performance. f-MWCNTs also cause a significant improvement on the polymerization reaction of PCL. Indeed, the in situ polymerization kinetics studies reveal a significant decrease in the reaction temperature, by a factor of 30-40 °C, combined with accelerated the reaction kinetics during initiation and propagation and a drastically reduced effective activation energy.

  8. Novel nitrogen-enriched oridonin analogues with thiazole-fused A-ring: protecting group-free synthesis, enhanced anticancer profile, and improved aqueous solubility.

    PubMed

    Ding, Chunyong; Zhang, Yusong; Chen, Haijun; Yang, Zhengduo; Wild, Christopher; Chu, Lili; Liu, Huiling; Shen, Qiang; Zhou, Jia

    2013-06-27

    Oridonin (1), a complex ent-kaurane diterpenoid isolated from the traditional Chinese herb Isodon rubescens , has demonstrated great potential in the treatment of various human cancers due to its unique and safe anticancer pharmacological profile. Nevertheless, the clinical development of oridonin for cancer therapy has been hampered by its relatively moderate potency, limited aqueous solubility, and poor bioavailability. Herein, we report the concise synthesis of a series of novel nitrogen-enriched oridonin derivatives with thiazole-fused A-ring through an efficient protecting group-free synthetic strategy. Most of them, including compounds 7-11, 13, and 14, exhibited potent antiproliferative effects against breast, pancreatic, and prostate cancer cells with low micromolar to submicromolar IC50 values as well as markedly enhanced aqueous solubility. These new analogues obtained by rationally modifying the natural product have been demonstrated not only to significantly induce the apoptosis and suppress growth of triple-negative MDA-MB-231 breast cancer both in vitro and in vivo but also effective against drug-resistant ER-positive MCF-7 clones. PMID:23746196

  9. The formation of Jupiter's faint rings

    PubMed

    Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

    1999-05-14

    Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets.

  10. The formation of Jupiter's faint rings

    PubMed

    Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

    1999-05-14

    Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets. PMID:10325220

  11. [Suppurative intracranial infections in Africa].

    PubMed

    Loembe, P M; Okome-Kouakou, M; Alliez, B

    1997-01-01

    The purpose of this study was to review recent African literature on suppurative intracranial infection and its implications for neurosurgery. In order of decreasing frequency the main lesions are brain abscess, subdural empyema, and epidural abscess. Despite progress in diagnostic imaging and availability of antibiotic therapy, these lesions still cause disturbingly high morbidity and mortality especially in sub-Saharan Africa where diagnosis is often delayed. The male-to-female ratio was 3.6:1 and 70 to 80% of patients were under the age of 20 years. Spread from the paranasal sinus or ear was the most common mechanism of infection. Hematogenous processes accounted for 22% of cases and the origin was undetermined in 11% to 26% of cases. Staphylococcus aureus and enteric gram-negative bacilli were the most common bacteria identified but cultures were reported as sterile in 30% to 50% of cases. While ultrasonography can be useful in newborns with an open fontanelle, arteriography is often the only feasible procedure for diagnosis in Black Africa. The diagnostic modality of choice is computed tomography which allows precise mapping prior to neurosurgery. Introduction of computed tomography in some African cities has led to a decrease in mortality ranging from 4.7% to 43%. The most effective treatment is a combination of appropriate antimicrobial therapy and surgical decompression of expanding lesions. The main procedures are aspiration through burr holes and craniotomy. Use of this combined strategy requires close cooperation between the neurosurgeon, infectious disease specialist, and microbiologist. Therapeutic indications are discussed within the context of Black Africa. PMID:9304016

  12. Spectral Imaging for Intracranial Stents and Stent Lumen

    PubMed Central

    Chen, David Yen-Ting; Chen, Chi-Jen; Hsu, Hui-Ling

    2016-01-01

    Introduction Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen. Materials and Methods In vitro, we scanned Enterprise stent phantom and a stent–cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20. Results In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P < .05) and showed the highest mean grading score (2.94 ± 0.94; P < .05) and contrast/noise ratio of in-stent lumen (160.03 ±37.79; P < .05) among all the modes. Conclusion Iodine (water) images can help reduce stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis. PMID:26731534

  13. Prevention and treatment of intracranial hypertension.

    PubMed

    Jantzen, Jan-Peter A H

    2007-12-01

    Intracranial pressure (ICP) is the pressure exerted by cranial contents on the dural envelope. It comprises the partial pressures of brain, blood and cerebrospinal fluid (CSF). Normal intracranial pressure is somewhere below 10 mmHg; it may increase as a result of traumatic brain injury, stroke, neoplasm, Reye's syndrome, hepatic coma, or other pathologies. When ICP increases above 20 mmHg it may damage neurons and jeopardize cerebral perfusion. If such a condition persists, treatment is indicated. Control of ICP requires measurement, which can only be performed invasively. Standard techniques include direct ventricular manometry or measurement in the parenchyma with electronic or fiberoptic devices. Displaying the time course of pressure (high-resolution ICP tonoscopy) allows assessment of the validity of the signal and identification of specific pathological findings, such as A-, B- and C-waves. When ICP is pathologically elevated--at or above 20-25 mmHg--it needs to be lowered. A range of treatment modalities is available and should be applied with consideration of the underlying cause. When intracranial hypertension is caused by hematoma, contusion, tumor, hygroma, hydrocephalus or pneumatocephalus, surgical treatment is indicated. In the absence of a surgically treatable condition, ICP may be controlled by correcting the patient's position, temperature, ventilation or hemodynamics. If intracranial hypertension persists, drainage of CSF via external drainage is most effective. Other first-tier options include induced hypocapnea (hyperventilation; paCO2 < 35 mmHg), hyperosmolar therapy (mannitol, hypertonic saline) and induced arterial hypertension (CPP concept). When autoregulation of cerebral blood flow is compromised, hyperoncotic treatment aimed at reducing vasogenic edema and intracranial blood volume may be applied. When intracranial hypertension persists, second-tier treatments may be indicated. These include 'forced hyperventilation' (paCO2 < 25 mm

  14. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intracranial pressure monitoring device. 882.1620... pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The...

  15. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intracranial pressure monitoring device. 882.1620... pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The...

  16. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intracranial pressure monitoring device. 882.1620... pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The...

  17. 21 CFR 882.1620 - Intracranial pressure monitoring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intracranial pressure monitoring device. 882.1620... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1620 Intracranial pressure monitoring device. (a) Identification. An intracranial pressure monitoring device is a device...

  18. Measuring Intracranial Pressure And Volume Noninvasively

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.; Yost, William T.

    1994-01-01

    Ultrasonic technique eliminates need to drill into brain cavity. Intracranial dynamics instrument probes cranium ultrasonically to obtain data for determination of intracranial pressure (ICP) and pressure-volume index (PVI). Instrument determines sensitivity of skull to changes in pressure and by use of mechanical device to exert external calibrated pressure on skull. By monitoring volume of blood flowing into jugular vein, one determines change of volume of blood in cranial system. By measuring response of skull to increasing pressure (where pressure increased by tilting patient known amount) and by using cranial blood pressure, one determines intial pressure in cerebrospinal fluid. Once PVI determined, ICP determined.

  19. Intracranial Vertebral Artery Dissections: Evolving Perspectives

    PubMed Central

    Ali, M.S.; Amenta, P.S.; Starke, R.M.; Jabbour, P.M.; Gonzalez, L.F.; Tjoumakaris, S.I.; Flanders, A.E.; Rosenwasser, R.H.; Dumont, A.S.

    2012-01-01

    Summary Intracranial vertebral artery dissection (VAD) represents the underlying etiology in a significant percentage of posterior circulation ischemic strokes and subarachnoid hemorrhages. These lesions are particularly challenging in their diagnosis, management, and in the prediction of long-term outcome. Advances in the understanding of underlying processes leading to dissection, as well as the evolution of modern imaging techniques are discussed. The data pertaining to medical management of intracranial VADs, with emphasis on anticoagulants and antiplatelet agents, is reviewed. Surgical intervention is discussed, including, the selection of operative candidates, open and endovascular procedures, and potential complications. The evolution of endovascular technology and techniques is highlighted. PMID:23217643

  20. Deployable Fresnel Rings

    NASA Technical Reports Server (NTRS)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

    2014-01-01

    Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

  1. CSF imaging in benign intracranial hypertension

    PubMed Central

    James, A. Everette; Harbert, J. C.; Hoffer, P. B.; DeLand, F. H.

    1974-01-01

    The cisternographic images in 10 patients with benign intracranial hypertension were reviewed. Nine were normal. Transfer of labelled tracer from the subarachnoid space was measured in five patients and was found to be abnormal in only two. The relation of these findings to the proposed pathophysiological alterations is discussed. Images

  2. Isotope cisternography in patients with intracranial hypertension

    SciTech Connect

    Hayashi, M.; Kobayashi, H.; Kawano, H.; Handa, Y.; Kabuto, M.; Noguchi, Y.; Shirasaki, H.

    1986-04-01

    Cerebrospinal fluid flow (CSF) was studied using isotope cisternography in 52 patients with increased intracranial pressure (ICP), all of whom showed acute transient rises of ICP, i.e., plateau waves, in their continuous ICP recordings. The patients were assigned to two groups. Group I was comprised of 23 patients without hydrocephalus and high ICP resulting from brain tumors, benign intracranial hypertension, and superior sagittal sinus thrombosis. Group II included 29 patients with either communicating hydrocephalus or high ICP resulting from rupture of intracranial aneurysm. Plateau waves were frequently observed in patients with baseline pressures ranging from 21 to 40 mmHg in both groups. The isotope cisternographic pattern in the Group I patients showed a large accumulation of radioactivity over the cerebral convexities, while that in the Group II patients revealed a complete obstruction of the subarachnoid space over both cerebral convexities. The isotope clearance from the intracranial CSF showed a marked delay in both groups of patients with one exception. The results suggest that, in the limited range of increased ICP caused by delayed CSF absorption, plateau waves are most evident regardless of the isotope cisternographic pattern.

  3. Varied computed tomographic appearance of intracranial cryptococcosis

    SciTech Connect

    Cornell, S.H.; Jacoby, C.G.

    1982-06-01

    CT findings in 12 cases of intracranial cryptococcal infection were reviewed. Five patients had a normal scan. Seven patients had communicating or noncommunicating hydrocephalus. Additional findings included meningeal opacification, cerebritis, abscess, and granuloma. Although not specific for cryptococcosis, the CT scan is helpful for evaluating and following the status of the ventricles, subarachnoid spaces, and meninges.

  4. The Intracranial Volume Pressure Response in Increased Intracranial Pressure Patients: Clinical Significance of the Volume Pressure Indicator

    PubMed Central

    2016-01-01

    Background For patients suffering from primary brain injury, monitoring intracranial pressure alone is not enough to reflect the dynamic intracranial condition. In our previous study, a segment of the pressure-volume curve can be expressed by the parabolic regression model with single indicator “a”. The aim of this study is to evaluate if the indicator “a” can reflect intracranial conditions. Methods Patients with traumatic brain injury, spontaneous intracranial hemorrhage, and/or hydrocephalus who had external ventricular drainage from January 2009 to February 2010 were included. The successive volume pressure response values were obtained by successive drainage of cerebral spinal fluid from intracranial pressure 20–25 mm Hg to 10 mm Hg. The relationship between withdrawn cerebral spinal fluid volume and intracranial pressure was analyzed by the parabolic regression model with single parameter “a”. Results The overall mean for indicator “a” was 0.422 ± 0.046. The mean of “a” in hydrocephalus was 0.173 ± 0.024 and in severe intracranial mass with slender ventricle, it was 0.663 ± 0.062. The two extreme intracranial conditions had a statistical significant difference (p<0.001). Conclusion The indicator “a” of a pressure-volume curve can reflect the dynamic intracranial condition and is comparable in different situations. A significantly larger indicator “a” with increased intracranial pressure is always observed in severe intracranial mass lesions with cerebral edema. A significantly smaller indicator “a” with increased intracranial pressure is observed in hydrocephalus. Brain computed tomography should be performed early if a rapid elevation of indicator “a” is detected, as it can reveal some ongoing intracranial pathology prior to clinical deterioration. Increased intracranial pressure was frequently observed in patients with intracranial pathology. The progression can be differentiated using the pattern of the volume

  5. Age at intracranial aneurysm rupture among generations

    PubMed Central

    Woo, D; Hornung, R; Sauerbeck, L; Brown, R; Meissner, I; Huston, J; Foroud, T; Broderick, J

    2009-01-01

    Background: Previous studies have reported intracranial aneurysm (IA) occurring at young ages in subsequent generations. These studies did not correct for duration of follow-up. Second-generation members who would have their ruptured IA late in life may not be detected due to shorter follow-up time than the first generation. We examined families in which ruptured IA occurred in two consecutive generations for the hypothesis that the second generation (F1) was more likely to have a rupture at a younger age than the older generation (F0). Methods: The Familial Intracranial Aneurysm (FIA) Study is a multicenter, international study recruiting families of ruptured and unruptured IA. All available family members are interviewed. Cox proportional hazards regression models and Kaplan-Meier curves were used to examine differences by generation. Results: Although we found that the F1 generation was more likely to have an aneurysm rupture at a younger age than the F0 generation, we found that this was largely because of a lack of follow-up time in the F1 generation. The F1 generation had 50% the rupture rate of the prior generation. When analyzed by Kaplan-Meier curves, we found a tendency to have a slightly later rupture rate in the F1 generation once time to follow-up was included in the analysis model. Conclusions: Families of ruptured intracranial aneurysm (IA) do not appear to demonstrate “anticipation.” Our finding suggests that genetic epidemiology of ruptured IA should examine all types of variations such as single base-pair changes, deletions, insertions, and other variations that do not demonstrate anticipation. GLOSSARY FIA = familial intracranial aneurysm; IA = intracranial aneurysm; SAH = subarachnoid hemorrhage. PMID:19237697

  6. Ringing wormholes

    SciTech Connect

    Konoplya, R.A.; Molina, C.

    2005-06-15

    We investigate the response of traversable wormholes to external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in the two brane Randall-Sundrum model and was previously found within Einstein gravity with a conformally coupled scalar field. The evolution of perturbations of a wormhole is similar to that of a black hole and represents damped oscillations (ringing) at intermediately late times, which are suppressed by power-law tails (proportional to t{sup -2} for monopole perturbations) at asymptotically late times.

  7. A giant frontoethmoid mucocele with intracranial extension.

    PubMed

    Işık, Abdülcemal Ümit; Arslan, Selçuk; Arslan, Erhan; Baykal, Süleyman

    2015-02-01

    Mucoceles are mucus-containing cysts lined by epithelium. Although benign, they may show expansive growth and remain undiagnosed until symptoms due to compression of surrounding structures arise. We report a rare case of frontoethmoid mucocele with intracranial extension in an 80-year-old woman with complaints of headache, right diplopia and proptosis. A right frontoorbital craniotomy was performed, and a mucocele in the frontal sinus extending into the frontal lobe and orbit was totally removed. The patient was successfully treated without any complication. The two-year follow-up results were satisfactory. Magnetic resonance imaging excluded any recurrence of the mucocele. Combined intranasal and transcranial approach is necessary to treat giant frontoetmoid mucoceles with intracranial extension.

  8. Method for noninvasive intracranial pressure measurement

    SciTech Connect

    Sinha, Dipen N.

    2000-01-01

    An ultrasonic-based method for continuous, noninvasive intracranial pressure (ICP) measurement and monitoring is described. The stress level in the skull bone is affected by pressure. This also changes the interfacial conditions between the dura matter and the skull bone. Standing waves may be set up in the skull bone and the layers in contact with the bone. At specific frequencies, there are resonance peaks in the response of the skull which can be readily detected by sweeping the excitation frequency on an excitation transducer in contact with a subject's head, while monitoring the standing wave characteristics from the signal received on a second, receiving transducer similarly in contact with the subject's head. At a chosen frequency, the phase difference between the excitation signal and the received signal can be determined. This difference can be related to the intracranial pressure and changes therein.

  9. Intracranial Artery Calcification and Its Clinical Significance

    PubMed Central

    Wu, Xiao Hong; Wang, Li Juan; Wong, Ka Sing

    2016-01-01

    Intracranial arterial calcification (IAC) is an easily identifiable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. The severity of IAC can be assessed using different visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. There is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke—through direct arterial stenosis or plaque stability—remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms. PMID:27165425

  10. An unusual intracranial metastasis of osteosarcoma.

    PubMed

    Chang, J W; Howng, S L; Sun, Z M; Kuo, T H; Duh, C C

    1994-12-01

    Intracranial metastasis is unusual in osteosarcoma. A case of osteosarcoma was presented with a large intracranial "stone" which was a subdural convexity metastasis. Smaller epidural metastases over other areas were noted also in brain CT scan. Using the radiographs and bone scans, many other lesions at bones, the mediastinum, pleura, perirenal space, and adrenal gland were detected simultaneously. This condition might result from either early metastases or multifocal osteosarcomas. Because many of the above lesion sites were not frequent locations of primary osteosarcoma and had been reported as metastatic targets of osteosarcoma. So the explanation of a very malignant osteosarcoma with early metastases may be more appropriate for this case. The baseball-like tumor in the subdural space with marked compression of the brain surface was grossly totally excised. Histopathologic examination confirmed the diagnosis of osteosarcoma. Postoperatively, the man's condition improved dramatically, though only for two months. He died 5 months later. Reports of such metastatic osteosarcomas are reviewed.

  11. Giant intracranial aneurysms: rapid sequential computed tomography

    SciTech Connect

    Pinto, R.S.; Cohen, W.A.; Kricheff, I.I.; Redington, R.W.; Berninger, W.H.

    1982-11-01

    Giant intracranial aneurysms often present as mass lesions rather than with subarachnoid hemorrhage. Routine computed tomographic (CT) scans with contrast material will generally detect them, but erroneous diagnosis of basal meningioma is possible. Rapid sequential scanning (dynamic CT) after bolus injection of 40 ml of Renografin-76 can conclusively demonstrate an intracranial aneurysm, differentiating it from other lesions by transit-time analysis of the passage of contrast medium. In five patients, the dynamics of contrast bolus transit in aneurysms were consistently different from the dynamics in pituitary tumors, craniopharyngiomas, and meningiomas, thereby allowing a specific diagnosis. Dynamic CT was also useful after treatment of the aneurysms by carotid artery ligation and may be used as an alternative to angiographic evaluation in determining luminal patency or thrombosis.

  12. The contemporary management of intracranial atherosclerotic disease.

    PubMed

    Leng, Xinyi; Wong, Ka Sing; Leung, Thomas W

    2016-06-01

    Intracranial atherosclerotic disease is the most common cause of cerebral vasculopathy and an important stroke etiology worldwide, with a higher prevalence in Asian, Hispanic and African ethnicities. Symptomatic intracranial atherosclerotic disease portends a recurrent stroke risk as high as 18% at one year. The key to secondary prevention is an understanding of the underlying stroke mechanism and aggressive control of conventional cardiovascular risks. Contemporary treatment includes antiplatelet therapy, optimal glycemic and blood pressure control, statin therapy and lifestyle modifications. For patients with high-grade (70-99%) symptomatic steno-occlusion, short-term dual antiplatelet therapy with aspirin and clopidogrel followed by life-long single antiplatelet therapy may reduce the recurrent risk. Current evidence does not advocate percutaneous transluminal angioplasty and stenting as an initial treatment. External counterpulsation, encephaloduroarteriosynangiosis and remote limb ischemic preconditioning are treatments under investigation. Future studies should aim at predicting patients prone to recurrence despite of medical therapies and testing the efficacy of emerging therapies.

  13. Multiple Intracranial Aneurysms in HIV Infection.

    PubMed

    Dhawan, Sumeet R; Gupta, Anju; Gupta, Vivek; Singhi, Pratibha D

    2016-08-01

    Neurological findings in HIV are common and include cognitive impairment, microcephaly, nonspecific white matter lesions and seizures. Cerebral vasculopathy and stroke are uncommon and may be due to primary HIV vasculopathy or opportunistic infections such as tuberculosis and cryptococcal meningitis. The authors describe a 7-y-old boy who presented with severe headache and was detected to have aneurysmal bleed due to intracranial aneurysm. PMID:27072660

  14. Filum ependymoma mimicking spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Akopov, Sergey E

    2005-05-01

    A 34-year-old man with a 2-week history of orthostatic headaches and a "dry tap" at lumbar puncture was found to have a lumbar intradural mass on magnetic resonance imaging (MRI) examination. A myxopapillary ependymoma was resected and the patient's headache completely resolved. The combination of spontaneous orthostatic headaches and a "dry tap" at the time of lumbar puncture does not always indicate the presence of a spontaneous cerebrospinal fluid (CSF) leak and intracranial hypotension. PMID:15953283

  15. Spaceflight-Induced Intracranial Hypertension: An Overview

    NASA Technical Reports Server (NTRS)

    Traver, William J.

    2011-01-01

    This slide presentation is an overview of the some of the known results of spaceflight induced intracranial hypertension. Historical information from Gemini 5, Apollo, and the space shuttle programs indicated that some vision impairment was reported and a comparison between these historical missions and present missions is included. Optic Disc Edema, Globe Flattening, Choroidal Folds, Hyperopic Shifts and Raised Intracranial Pressure has occurred in Astronauts During and After Long Duration Space Flight. Views illustrate the occurrence of Optic Disc Edema, Globe Flattening, and Choroidal Folds. There are views of the Arachnoid Granulations and Venous return, and the question of spinal or venous compliance issues is discussed. The question of increased blood flow and its relation to increased Cerebrospinal fluid (CSF) is raised. Most observed on-orbit papilledema does not progress, and this might be a function of plateau homeostasis for the higher level of intracranial pressure. There are seven cases of astronauts experiencing in flight and post flight symptoms, which are summarized and follow-up is reviewed along with a comparison of the treatment options. The question is "is there other involvement besides vision," and other Clinical implications are raised,

  16. Emergency management of increased intracranial pressure.

    PubMed

    Pitfield, Alexander Fraser; Carroll, Allison B; Kissoon, Niranjan

    2012-02-01

    Primary neurological injury in children can be induced by diverse intrinsic and extrinsic factors including brain trauma, tumors, and intracranial infections. Regardless of etiology, increased intracranial pressure (ICP) as a result of the primary injury or delays in treatment may lead to secondary (preventable) brain injury. Therefore, early diagnosis and aggressive treatment of increased ICP is vital in preventing or limiting secondary brain injury in children with a neurological insult. Present management strategies to improve survival and neurological outcome focus on reducing ICP while optimizing cerebral perfusion and meeting cerebral metabolic demands. Targeted therapies for increased ICP must be considered and implemented as early as possible during and after the initial stabilization of the child. Thus, the emergency physician has a critical role to play in early identification and treatment of increased ICP. This article intends to identify those patients at risk of intracranial hypertension and present a framework for the emergency department investigation and treatment, in keeping with contemporary guidelines. Intensive care management and the treatment of refractory increases in ICP are also outlined.

  17. A segmentation algorithm of intracranial hemorrhage CT image

    NASA Astrophysics Data System (ADS)

    Wang, Haibo; Chen, Zhiguo; Wang, Jianzhi

    2011-10-01

    To develop a computer aided detection (CAD) system that improves diagnostic accuracy of intracranial hemorrhage on cerebral CT. A method for CT image segmentation of brain is proposed, with which, several regions that are suspicious of hemorrhage can be segmented rapidly and effectively. Extracting intracranial area algorithm is introduced firstly to extract intracranial area. Secondly, FCM is employed twice, we named it with TFCM. FCM is first employed to identify areas of intracranial hemorrhage. Finally, FCM is employed to segment the lesions. Experimental results on real medical images demonstrate the efficiency and effectiveness.

  18. Progressive intracranial fusiform aneurysms and T-cell immunodeficiency.

    PubMed

    Piantino, Juan A; Goldenberg, Fernando D; Pytel, Peter; Wagner-Weiner, Linda; Ansari, Sameer A

    2013-02-01

    In the pediatric population, intracranial fusiform aneurysms have been associated with human immunodeficiency virus/acquired immunodeficiency syndrome and rarely with opportunistic infections related to other immunodeficiencies. The HIV virus and other infectious organisms have been implicated in the pathophysiology of these aneurysms. We present a child with T-cell immunodeficiency but no evidence of human immunodeficiency virus or opportunistic intracranial infections that developed progressive bilateral fusiform intracranial aneurysms. Our findings suggest a role of immunodeficiency or inflammation in the formation of some intracranial aneurysms.

  19. [Prolonged hypothermia in refractory intracranial hypertension. Report of one case].

    PubMed

    Rovegno, Maximiliano; Valenzuela, José Luis; Mellado, Patricio; Andresen, Max

    2012-02-01

    The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies.

  20. Pituitary apoplexy syndrome as the manifestation of intracranial tuberculoma

    PubMed Central

    Verma, Rajesh; Patil, Tushar B; Lalla, Rakesh

    2014-01-01

    Pituitary apoplexy syndrome is characterised by acute neuro-ophthalmological features and usually occurs due to bleeding in a pituitary adenoma. It is an unusual presentation of tuberculoma, as only few similar cases have been reported previously. A 17-year-old girl presented with headache, vomiting, altered sensorium and vision loss. MRI of the brain revealed ring enhancing sellar lesions with other enhancing lesions and leptomeningeal enhancement. Cerebrospinal fluid microscopy, biochemistry and PCR for tuberculosis confirmed tubercular meningitis. The patient was treated with antituberculous therapy and was asymptomatic at the end of treatment. PMID:24675800

  1. Asymmetric dipolar ring

    DOEpatents

    Prosandeev, Sergey A.; Ponomareva, Inna V.; Kornev, Igor A.; Bellaiche, Laurent M.

    2010-11-16

    A device having a dipolar ring surrounding an interior region that is disposed asymmetrically on the ring. The dipolar ring generates a toroidal moment switchable between at least two stable states by a homogeneous field applied to the dipolar ring in the plane of the ring. The ring may be made of ferroelectric or magnetic material. In the former case, the homogeneous field is an electric field and in the latter case, the homogeneous field is a magnetic field.

  2. B-Ring-Aryl Substituted Luotonin A Analogues with a New Binding Mode to the Topoisomerase 1-DNA Complex Show Enhanced Cytotoxic Activity

    PubMed Central

    González-Ruiz, Víctor; Pascua, Irene; Fernández-Marcelo, Tamara; Ribelles, Pascual; Bianchini, Giulia; Sridharan, Vellaisamy; Iniesta, Pilar; Ramos, M. Teresa; Olives, Ana I.; Martín, M. Antonia; Menéndez, J. Carlos

    2014-01-01

    Topoisomerase 1 inhibition is an important strategy in targeted cancer chemotherapy. The drugs currently in use acting on this enzyme belong to the family of the camptothecins, and suffer severe limitations because of their low stability, which is associated with the hydrolysis of the δ-lactone moiety in their E ring. Luotonin A is a natural camptothecin analogue that lacks this functional group and therefore shows a much-improved stability, but at the cost of a lower activity. Therefore, the development of luotonin A analogues with an increased potency is important for progress in this area. In the present paper, a small library of luotonin A analogues modified at their A and B rings was generated by cerium(IV) ammonium nitrate-catalyzed Friedländer reactions. All analogues showed an activity similar or higher than the natural luotonin A in terms of topoisomerase 1 inhibition and some compounds had an activity comparable to that of camptothecin. Furthermore, most compounds showed a better activity than luotonin A in cell cytotoxicity assays. In order to rationalize these results, the first docking studies of luotonin-topoisomerase 1-DNA ternary complexes were undertaken. Most compounds bound in a manner similar to luotonin A and to standard topoisomerase poisons such as topotecan but, interestingly, the two most promising analogues, bearing a 3,5-dimethylphenyl substituent at ring B, docked in a different orientation. This binding mode allows the hydrophobic moiety to be shielded from the aqueous environment by being buried between the deoxyribose belonging to the G(+1) guanine and Arg364 in the scissile strand and the surface of the protein and a hydrogen bond between the D-ring carbonyl and the basic amino acid. The discovery of this new binding mode and its associated higher inhibitory potency is a significant advance in the design of new topoisomerase 1 inhibitors. PMID:24830682

  3. Keck infrared observations of Saturn's main rings bracketing Earth's August 1995 ring plane crossing

    NASA Astrophysics Data System (ADS)

    Verbanac, Giuli; de Pater, Imke; Showalter, Mark R.; Lissauer, Jack J.

    2005-03-01

    We present results of near-infrared (2.26 μm) observations of Saturn's main rings taken with the W.M. Keck telescope during August 8-11, 1995, surrounding the time that Earth crossed Saturn's ring plane. These observations provide a unique opportunity to study the evolution of the ring brightness in detail, and by combining our data with Hubble Space Telescope (HST) results (Nicholson et al., 1996, Science 272, 453-616), we extend the 12-hour HST time span to several days around the time of ring plane crossing (RPX). In this paper, we focus on the temporal evolution of the brightness in Saturn's main rings. We examine both edge-on ring profiles and radial profiles obtained by "onion-peeling" the edge-on data. Before RPX, when the dark (unlit) face of the rings was observed, the inner C ring (including the Colombo gap), the Maxwell gap, Cassini Division and F ring region were very bright in transmitted light. After RPX, the main rings brighten rapidly, as expected. The profiles show east-west asymmetries both before and after RPX. Prior to RPX, the evolution in ring brightness of the Keck and HST data match one another quite well. The west side of the rings showed a nonlinear variation in brightness during the last hours before ring plane crossing, suggestive of clumping and longitudinal asymmetries in the F ring. Immediately after RPX, the east side of the rings brightened more rapidly than the west. A quantitative comparison of the Keck and HST data reveals that the rings were redder before RPX than after; we ascribe this difference to the enhanced multiple scattering of photons passing through to the unlit side of the rings.

  4. [Intracranial tumors and epileptic seizures: treatment principles].

    PubMed

    Rossetti, Andrea O; Vulliémoz, Serge

    2016-04-27

    Epileptic seizures represent a relatively frequent issue in patients with intracranial neoplasms, and very frequently imply the start of an antiepileptic treatment as secondary prophylaxis. Even if the current level of evidence is relatively low, compounds with a limited risk of pharmacokinetic interactions are clearly preferred. Levetiracetam is probably the most prescribed agent in this setting, while pregabalin, valproate, lacosamide and lamotrigine are valuable alternatives. The treatment choice has to consider the different profiles of side effects and should be tailored to each patient. In this setting, a multidisciplinary approach including general practicioner, oncologist and neurologist is strongly advocated. PMID:27281943

  5. Intracranial blister aneurysms: clip reconstruction techniques.

    PubMed

    Barrow, Daniel L; Pradilla, Gustavo; McCracken, D Jay

    2015-07-01

    Intracranial blister aneurysms are difficult to treat cerebrovascular lesions that typically affect the anterior circulation. These rare aneurysms can lead to acute rupture which usually cannot be treated via endovascular methods, but still require urgent surgical intervention. Surgical options are limited given their unique pathology and often require a combination of wrapping and clip reconstruction. In this video we present two patients with acute subarachnoid hemorrhage secondary to ruptured blister aneurysms. We demonstrate several surgical techniques for repairing the vascular defect with and without intraoperative rupture. The video can be found here: http://youtu.be/nz-JM45uKQU.

  6. Recovery from Intracranial Hemorrhage Due to Leptospirosis

    PubMed Central

    Babamahmoodi, Farhang; Babamhmoodi, Abdolreza

    2011-01-01

    Intracranial hemorrhage is a rare and fatal presentation of leptospirosis. In this paper we present the case of a 51-year-old male farmer who lives in northern Iran. He came to our hospital with a severe headache. A paraclinical evaluation showed clear signs of thrombocytopenia, and a brain MRI revealed left temporoparietal hemorrhage. Our preliminary diagnosis was Leptospirosis, and after 26 days of hospital care the patient was discharged in good condition. This paper will educationally help physicians in better diagnosis and treatment of leptospirosis. PMID:22013452

  7. Clarithromycin Culprit of Benign Intracranial Hypertension.

    PubMed

    Khan, Habib Rehman; Mason, Colin; Mulcahy, Riona

    2015-01-01

    Benign intracranial hypertension is characterized with increase in CSF opening pressure with no specific etiology. It is predominantly found in women of child bearing age and particularly in individuals with obesity. Visual disturbances or loss and associated headaches are common and can lead to blindness if left untreated. Diagnosis can be achieved once other causes of visual loss, headaches and high opening pressures are excluded. Management consists of serial optic disc assessments although no specific treatment is available despite recent trials using carbonic anhydrase inhibitors. Diet modification and weight management can help in therapy. PMID:26713029

  8. Spatial contrast sensitivity in benign intracranial hypertension.

    PubMed

    Bulens, C; Meerwaldt, J D; Koudstaal, P J; Van der Wildt, G J

    1988-10-01

    Spatial Contrast Sensitivity (CS) was studied in 20 patients with benign intracranial hypertension (BIH). At presentation CS loss was found in 43% of the eyes, and impairment of visual acuity attributed to BIH in only 16%. Nine patients had blurred vision or visual obscurations, all of whom had abnormal CS. The clinical application of CS measurement in BIH for monitoring the progression or regression of the disease is illustrated by serial measurements in 11 patients. Progressive visual loss in longstanding papilloedema and improvement of visual function in subsiding papilloedema can occur without any change in Snellen acuity or visual field charting.

  9. Spatial contrast sensitivity in benign intracranial hypertension.

    PubMed Central

    Bulens, C; Meerwaldt, J D; Koudstaal, P J; Van der Wildt, G J

    1988-01-01

    Spatial Contrast Sensitivity (CS) was studied in 20 patients with benign intracranial hypertension (BIH). At presentation CS loss was found in 43% of the eyes, and impairment of visual acuity attributed to BIH in only 16%. Nine patients had blurred vision or visual obscurations, all of whom had abnormal CS. The clinical application of CS measurement in BIH for monitoring the progression or regression of the disease is illustrated by serial measurements in 11 patients. Progressive visual loss in longstanding papilloedema and improvement of visual function in subsiding papilloedema can occur without any change in Snellen acuity or visual field charting. PMID:3225588

  10. Whole-body mathematical model for simulating intracranial pressure dynamics

    NASA Technical Reports Server (NTRS)

    Lakin, William D. (Inventor); Penar, Paul L. (Inventor); Stevens, Scott A. (Inventor); Tranmer, Bruce I. (Inventor)

    2007-01-01

    A whole-body mathematical model (10) for simulating intracranial pressure dynamics. In one embodiment, model (10) includes 17 interacting compartments, of which nine lie entirely outside of intracranial vault (14). Compartments (F) and (T) are defined to distinguish ventricular from extraventricular CSF. The vasculature of the intracranial system within cranial vault (14) is also subdivided into five compartments (A, C, P, V, and S, respectively) representing the intracranial arteries, capillaries, choroid plexus, veins, and venous sinus. The body's extracranial systemic vasculature is divided into six compartments (I, J, O, Z, D, and X, respectively) representing the arteries, capillaries, and veins of the central body and the lower body. Compartments (G) and (B) include tissue and the associated interstitial fluid in the intracranial and lower regions. Compartment (Y) is a composite involving the tissues, organs, and pulmonary circulation of the central body and compartment (M) represents the external environment.

  11. Ultrasonic Apparatus and Technique to Measure Changes in Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    Changes in intracranial pressure can be measured dynamically and non-invasively by monitoring one or more cerebrospinal fluid pulsatile components. Pulsatile components such as systolic and diastolic blood pressures are partially transferred to the cerebrospinal fluid by way of blood vessels contained in the surrounding brain tissue and membrane. As intracranial pressure varies these cerebrospinal fluid pulsatile components also vary. Thus, intracranial pressure can be dynamically measured. Furthermore, use of acoustics allows the measurement to be completely non-invasive. In the preferred embodiment, phase comparison of a reflected acoustic signal to a reference signal using a constant frequency pulsed phase-locked-loop ultrasonic device allows the pulsatile components to be monitored. Calibrating the device by inducing a known change in intracranial pressure allows conversion to changes in intracranial pressure.

  12. Stirling engine piston ring

    DOEpatents

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  13. Actin Rings of Power.

    PubMed

    Schwayer, Cornelia; Sikora, Mateusz; Slováková, Jana; Kardos, Roland; Heisenberg, Carl-Philipp

    2016-06-20

    Circular or ring-like actin structures play important roles in various developmental and physiological processes. Commonly, these rings are composed of actin filaments and myosin motors (actomyosin) that, upon activation, trigger ring constriction. Actomyosin ring constriction, in turn, has been implicated in key cellular processes ranging from cytokinesis to wound closure. Non-constricting actin ring-like structures also form at cell-cell contacts, where they exert a stabilizing function. Here, we review recent studies on the formation and function of actin ring-like structures in various morphogenetic processes, shedding light on how those different rings have been adapted to fulfill their specific roles. PMID:27326928

  14. The rings of Saturn

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.

    1978-01-01

    Consideration is given to the development of theories concerning the rings of Saturn. Particular attention is given to ring structure, noting its thinness, the separations between rings, and observed variations in brightness. Data gathered via infrared, radio and radar techniques are described in terms of ring particle composition and size. Hypotheses about ring origin and evolution are outlined, including the tidal disruption model, calculations of Saturn's gravitational contraction history, grazing, and meteoroid bombardment. Prospects for future observations of Saturn's rings are reviewed, such as the variation in their radar reflectivity as a function of the tilt of the ring plane.

  15. New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring

    SciTech Connect

    de Pater, I; Hammel, H B; Gibbard, S G; Showalter, M R

    2006-02-02

    We compare near-infrared observations of the recently discovered outer rings of Uranus with HST results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced via impacts into the embedded moon Mab, which apparently orbits at a location where non-gravitational perturbations favor the survival and spreading of sub-micron sized dust. R/2003 U 2 more closely resembles Saturn's G ring.

  16. Which Ringed Planet...!?

    NASA Astrophysics Data System (ADS)

    2002-12-01

    Don't worry - you are not the only one who thought this was a nice amateur photo of planet Saturn, Lord of the Rings in our Solar System! But then the relative brightness and positions of the moons may appear somewhat unfamiliar... and the ring system does look unusually bright when compared to the planetary disk...?? Well, it is not Saturn, but Uranus , the next giant planet further out, located at a distance of about 3,000 million km, or 20 times the distance between the Sun and the Earth. The photo shows Uranus surrounded by its rings and some of the moons, as they appear on a near-infrared image that was obtained in the K s -band (at wavelength 2.2 µm) with the ISAAC multi-mode instrument on the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory (Chile) . The exposure was made on November 19, 2002 (03:00 hrs UT) during a planetary research programme. The observing conditions were excellent (seeing 0.5 arcsec) and the exposure lasted 5 min. The angular diameter of Uranus is about 3.5 arcsec. The observers at ISAAC were Emmanuel Lellouch and Thérése Encrenaz of the Observatoire de Paris (France) and Jean-Gabriel Cuby and Andreas Jaunsen (both ESO-Chile). The rings The rings of Uranus were discovered in 1977, from observations during a stellar occultation event by astronomer teams at the Kuiper Airborne Observatory (KAO) and the Perth Observatory (Australia). Just before and after the planet moved in front of the (occulted) star, the surrounding rings caused the starlight to dim for short intervals of time. Photos obtained from the Voyager-2 spacecraft in 1986 showed a multitude of very tenuous rings. These rings are almost undetectable from the Earth in visible light. However, on the present VLT near-infrared picture, the contrast between the rings and the planet is strongly enhanced. At the particular wavelength at which this observation was made, the infalling sunlight is almost completely absorbed by gaseous methane present in the planetary atmosphere

  17. Severe intracranial haemorrhage in neonatal alloimmune thrombocytopenia

    PubMed Central

    Silva, Francisco; Morais, Sofia; Sevivas, Teresa; Veiga, Ricardo; Salvado, Ramon; Taborda, Adelaide

    2011-01-01

    Neonatal alloimmune thrombocytopenia is a rare (1/1000–5000 births) life-threatening disorder, caused by fetomaternal incompatibility for a fetal human platelet alloantigen inherited from the father, with production of maternal alloantibodies against fetal platelets, leading to severe thrombocytopenia and potential bleeding. Intracranial haemorrhage is the most feared complication. This report presents the case of a term newborn infant, born from caesarean section after a normal pregnancy, presenting signs of skin bleeding with different ages. Obstetric history included a previous spontaneous abortion after amniocentesis. Severe thrombocytopenia (4×109/l platelets) was found and brain ultrasound showed multiple intracranial haemorrhages. Human platelet antigen (HPA) phenotyping showed maternal negative HPA-1a and paternal positive HPA-1a platelets. Strongly positive anti-HPA-1a and weakly positive anti-human leukocyte antigen class I alloantibodies were found in the mother. Multiple platelet transfusions, intravenous immunoglobulin and corticosteroid were given but favourable response was accomplished only after a compatible platelet transfusion. Brain MRI showed multiple subacute and chronic haemorrhages. PMID:22679192

  18. Spontaneous thrombosis in giant intracranial aneurysms.

    PubMed Central

    Whittle, I R; Dorsch, N W; Besser, M

    1982-01-01

    Twelve patients in a series of 22 with giant intracranial aneurysms demonstrated neuroradiological features of partial or total spontaneous intra-aneurysmal thrombosis. The presence of this intra-aneurysmal clot significantly altered the computed tomographic appearance of the giant aneurysm. Massive intra-aneurysmal thrombosis did not protect against subarachnoid haemorrhage and the likelihood of rupture of a clot containing giant aneurysm was not significantly different from that of a non-thrombosed giant aneurysm. Although parent artery occlusion from a thrombosed giant aneurysm, and massive aneurysmal thrombosis leading to the formation of giant serpentine aneurysm were documented, these are rare epiphenomena. The risk of embolisation from a partially thrombosed giant aneurysm, which was documented in one case, would appear to be greater than that from a non-thrombosed giant aneurysm. The findings in this series, and a review of literature, suggest that the presence of intra-aneurysmal clot in giant intracranial aneurysms has little prognostic significance and does not alter the management or outcome after treatment. Images PMID:7175528

  19. Neuroblastoma with intracranial involvement: an ENSG Study.

    PubMed

    Shaw, P J; Eden, T

    1992-01-01

    We report the experience of the European Neuroblastoma Study Group (ENSG) with central nervous system (CNS) involvement of neuroblastoma. Among this series of intensively treated patients, CNS neuroblastoma was diagnosed by computerised tomography (CT) scanning, rather than by autopsy. Cranial disease occurred in 5% of ENSG patients. Of 11 patients with intracranial disease, 4 had disease in the posterior fossa, a site rarely reported previously. Furthermore, 5 cases had CNS metastases at a time when there was no detectable disease elsewhere, rather than as part of extensive relapse. The pattern of disease we observed, at least for those with parenchymal disease, is in keeping with arterial spread. Although CT scanning is the optimal modality for identifying CNS disease, 2 cases had normal head CT scans prior to the onset of CNS disease. As most patients had symptoms of raised intracranial pressure (RICP) at the time the CNS disease was diagnosed, there does not seem to be any indication for routine CT scanning of the head at diagnosis, but this should be performed as soon as any symptoms or signs appear. With patients living longer with their disease, vigilance must be maintained during follow-up. PMID:1734220

  20. Biology of intracranial aneurysms: role of inflammation

    PubMed Central

    Chalouhi, Nohra; Ali, Muhammad S; Jabbour, Pascal M; Tjoumakaris, Stavropoula I; Gonzalez, L Fernando; Rosenwasser, Robert H; Koch, Walter J; Dumont, Aaron S

    2012-01-01

    Intracranial aneurysms (IAs) linger as a potentially devastating clinical problem. Despite intense investigation, our understanding of the mechanisms leading to aneurysm development, progression and rupture remain incompletely defined. An accumulating body of evidence implicates inflammation as a critical contributor to aneurysm pathogenesis. Intracranial aneurysm formation and progression appear to result from endothelial dysfunction, a mounting inflammatory response, and vascular smooth muscle cell phenotypic modulation producing a pro-inflammatory phenotype. A later final common pathway appears to involve apoptosis of cellular constituents of the vessel wall. These changes result in degradation of the integrity of the vascular wall leading to aneurysmal dilation, progression and eventual rupture in certain aneurysms. Various aspects of the inflammatory response have been investigated as contributors to IA pathogenesis including leukocytes, complement, immunoglobulins, cytokines, and other humoral mediators. Furthermore, gene expression profiling of IA compared with control arteries has prominently featured differential expression of genes involved with immune response/inflammation. Preliminary data suggest that therapies targeting the inflammatory response may have efficacy in the future treatment of IA. Further investigation, however, is necessary to elucidate the precise role of inflammation in IA pathogenesis, which can be exploited to improve the prognosis of patients harboring IA. PMID:22781330

  1. Complex Coil Assisted Single Coil Embolization for Small Intracranial Aneurysm

    PubMed Central

    Yang, Tzu-Hsien; Ou, Chang-Hsien; Chan, Si-Wa; Chen, Tai-I; Yang, Chia-Jung; Chiang, Chia-Ming; Huang, Wen-Chien

    2013-01-01

    The purpose of the technical note is to introduce the complex coil assisted coil embolization method in the treatment of intracranial small aneurysm, in order to enhance the safety of the procedure. The first microcatheter was navigated into the aneurysm sac and the ultrasoft coil was used as the embolization coil. If the embolizations coil could not stay within the aneurysm sac smoothly, such as coil herniation into parent artery during the delivery process. The second microcatheter would be navigated to the aneurysm level in the parent artery. Another complex coil was delivered within the parent artery via the second microcatheter to provide the neck bridge effect in order to enhance the stability of embolization coil. Besides, the protection coil will not disturb the parent artery flow. While the embolization coil was put into the aneurysm sac smoothly under the help of complex protective coil, the protective coil was then withdrawn gently. We use the most magnified view, dual-plane approach simultaneously to observe the stability of embolization coil. The embolization coil would be detached without any evidence of coil motion or vibration. The new method could provide the physiological protective method, without leaving any protective device such as stent within the parent artery. PMID:24024075

  2. The rice RING finger E3 ligase, OsHCI1, drives nuclear export of multiple substrate proteins and its heterogeneous overexpression enhances acquired thermotolerance

    PubMed Central

    Lim, Sung Don; Cho, Hyun Yong; Park, Yong Chan; Ham, Deok Jae; Lee, Ju Kyong; Jang, Cheol Seong

    2013-01-01

    Thermotolerance is very important for plant survival when plants are subjected to lethally high temperature. However, thus far little is known about the functions of RING E3 ligase in response to heat shock in plants. This study found that one rice gene encoding the RING finger protein was specifically induced by heat and cold stress treatments but not by salinity or dehydration and named it OsHCI1 (Oryza sativa heat and cold induced 1). Subcellular localization results showed that OsHCI1 was mainly associated with the Golgi apparatus and moved rapidly and extensively along the cytoskeleton. In contrast, OsHCI1 may have accumulated in the nucleus under high temperatures. OsHCI1 physically interacted with nuclear substrate proteins including a basic helix-loop-helix transcription factor. Transient co-overexpression of OsHCI1 and each of three nuclear proteins showed that their fluorescent signals moved into the cytoplasm as punctuate formations. Heterogeneous overexpression of OsHCI1 in Arabidopsis highly increased survival rate through acquired thermotolerance. It is proposed that OsHCI1 mediates nuclear–cytoplasmic trafficking of nuclear substrate proteins via monoubiquitination and drives an inactivation device for the nuclear proteins under heat shock. PMID:23698632

  3. A dimensionless parameter for classifying hemodynamics in intracranial

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the most important factors correlated to the IA rupture are hemodynamic factors such as wall shear stress (WSS) and oscillatory shear index (OSI) which are affected by the IA flows. Here, we carry out three-dimensional high resolution simulations on representative IA models with simple geometries to test a dimensionless number (first proposed by Le et al., ASME J Biomech Eng, 2010), denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports across the IA neck to the time required for vortex ring formation. Based on the definition, the flow mode is vortex if An>1 and it is cavity if An<1. We show that the specific definition of Le et al. works for sidewall but needs to be modified for bifurcation aneurysms. In addition, we show that this classification works on three-dimensional geometries reconstructed from three-dimensional rotational angiography of human subjects. Furthermore, we verify the correlation of IA flow mode and WSS/OSI on the human subject IA. This work was supported partly by the NIH grant R03EB014860, and the computational resources were partly provided by CCR at UB. We thank Prof. Hui Meng and Dr. Jianping Xiang for providing us the database of aneurysms and helpful discussions.

  4. Accretion in Saturn's F Ring

    NASA Astrophysics Data System (ADS)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  5. Optimizing Thomson's jumping ring

    NASA Astrophysics Data System (ADS)

    Tjossem, Paul J. H.; Brost, Elizabeth C.

    2011-04-01

    The height to which rings will jump in a Thomson jumping ring apparatus is the central question posed by this popular lecture demonstration. We develop a simple time-averaged inductive-phase-lag model for the dependence of the jump height on the ring material, its mass, and temperature and apply it to measurements of the jump height for a set of rings made by slicing copper and aluminum alloy pipe into varying lengths. The data confirm a peak jump height that grows, narrows, and shifts to smaller optimal mass when the rings are cooled to 77 K. The model explains the ratio of the cooled/warm jump heights for a given ring, the reduction in optimal mass as the ring is cooled, and the shape of the mass resonance. The ring that jumps the highest is found to have a characteristic resistance equal to the inductive reactance of the set of rings.

  6. Feasibility of using the Vero SBRT system for intracranial SRS.

    PubMed

    Burghelea, Manuela; Verellen, Dirk; Gevaert, Thierry; Depuydt, Tom; Poels, Kenneth; Simon, Viorica; De Ridder, Mark

    2014-01-01

    The Vero SBRT system was benchmarked in a planning study against the Novalis SRS system for quality of delivered dose distributions to intracranial lesions and assessing the Vero system's capacity for SRS. A total of 27 patients with one brain lesion treated on the Novalis system, with 3 mm leaf width MLC and C-arm gantry, were replanned for Vero, with a 5 mm leaf width MLC mounted on an O-ring gantry allowing rotations around both the horizontal and vertical axis. The Novalis dynamic conformal arc (DCA) planning included vertex arcs, using 90° couch rotation. These vertex arcs cannot be reproduced with Vero due to the mechanical limitations of the O-ring gantry. Alternative class solutions were investigated for the Vero. Additionally, to distinguish between the effect of MLC leaf width and different beam arrangements on dose distributions, the Vero class solutions were also applied for Novalis. In addition, the added value of noncoplanar IMRT was investigated in this study. Quality of the achieved dose distributions was expressed in the conformity index (CI) and gradient index (GI), and compared using a paired Student's t-test with statistical significance for p-values ≤ 0.05. For lesions larger than 5 cm3, no statistical significant difference in conformity was observed between Vero and Novalis, but for smaller lesions, the dose distributions showed a significantly better conformity for the Novalis (ΔCI = 13.74%, p = 0.0002) mainly due to the smaller MLC leaf width. Using IMRT on Vero reduces this conformity difference to nonsignificant levels. The cutoff for achieving a GI around 3, characterizing a sharp dose falloff outside the target volume was 4 cm3 for Novalis and 7 cm3 for Vero using DCA technique. Using noncoplanar IMRT, this threshold was reduced to 3 cm3 for the Vero system. The smaller MLC and the presence of the vertex fields allow the Novalis system to better conform the dose around the lesion and to obtain steeper dose falloff outside the lesion

  7. Postural Effects on Intracranial Pressure as Assessed Noninvasively

    NASA Technical Reports Server (NTRS)

    Ueno, Toshiaki; Hargens, Alan R.; Ballard, R. E.; Shuer, L. M.; Cantrell, J. H.; Yost, W. T.; Holton, Emily M. (Technical Monitor)

    1997-01-01

    This study was designed to investigate effects of whole body tilting on intracranial compliance and pressure in six healthy volunteers by using a noninvasive ultrasonic device. Subjects were randomly tilted up or down sequentially at 60 degree, 30 degree head-up, supine, and 15 degree head-down position for one minute at each angle. We measured arterial blood pressure with a finger pressure cuff and changes in intracranial distance with an ultrasonic device. The device measures skull movement on the order of micro-meter. Our ultrasound technique demonstrates that skull movement is highly correlated (r$(circumflex){2}$=0.77) with intracranial pressure variations due to cerebral arterial pulsation. The amplitudes of arterial pressure (r$(circumflex){2}$=0.99 and those of intracranial distance changes (r$(circumflex){2}$=0.87) associated with one cardiac cycle were inversely correlated with the angle of tilt. The ratio of pulsation amplitudes for intracranial distance over arterial pressure also showed a significant increase as the angle of tilt was lowered (p=0.003). Thus, postural changes alter intracranial compliance in healthy volunteers and intracranial volume-buffering capacity is reduced in head-down position.

  8. Molecular basis and genetic predisposition to intracranial aneurysm

    PubMed Central

    Weinsheimer, Shantel; Ronkainen, Antti; Kuivaniemi, Helena

    2014-01-01

    Intracranial aneurysms, also called cerebral aneurysms, are dilatations in the arteries that supply blood to the brain. Rupture of an intracranial aneurysm leads to a subarachnoid hemorrhage, which is fatal in about 50% of the cases. Intracranial aneurysms can be repaired surgically or endovascularly, or by combining these two treatment modalities. They are relatively common with an estimated prevalence of unruptured aneurysms of 2%–6% in the adult population, and are considered a complex disease with both genetic and environmental risk factors. Known risk factors include smoking, hypertension, increasing age, and positive family history for intracranial aneurysms. Identifying the molecular mechanisms underlying the pathogenesis of intracranial aneurysms is complex. Genome-wide approaches such as DNA linkage and genetic association studies, as well as microarray-based mRNA expression studies, provide unbiased approaches to identify genetic risk factors and dissecting the molecular pathobiology of intracranial aneurysms. The ultimate goal of these studies is to use the information in clinical practice to predict an individual's risk for developing an aneurysm or monitor its growth or rupture risk. Another important goal is to design new therapies based on the information on mechanisms of disease processes to prevent the development or halt the progression of intracranial aneurysms. PMID:25117779

  9. Future studies of planetary rings by space probes

    NASA Technical Reports Server (NTRS)

    Stone, E. C.

    1984-01-01

    Recent space probe observations of the rings of Jupiter and Saturn have furnished a substantial enhancement of the current understanding of the outer planets' rings. Voyager 2 offers further opportunities for the study of the Neptune and Uranus ring systems. The Galileo mission to Jupiter furnishes the first opportunity for long term space probe studies of a planetary ring system. It is suggested that an appropriately instrumented Saturn orbiter would not only provide a similar opportunity for the study of the Saturn rings, but may also be the only means by which to adequately address the nature of the diverse phenomena displayed by this prototypical planetary ring system.

  10. The Idiopathic Intracranial Hypertension Treatment Trial

    PubMed Central

    Wall, Michael; Kupersmith, Mark J.; Kieburtz, Karl D.; Corbett, James J.; Feldon, Steven E.; Friedman, Deborah I.; Katz, David M.; Keltner, John L.; Schron, Eleanor B.; McDermott, Michael P.

    2015-01-01

    IMPORTANCE To our knowledge, there are no large prospective cohorts of untreated patients with idiopathic intracranial hypertension (IIH) to characterize the disease. OBJECTIVE To report the baseline clinical and laboratory features of patients enrolled in the Idiopathic Intracranial Hypertension Treatment Trial. DESIGN, SETTING, AND PARTICIPANTS We collected data at baseline from questionnaires, examinations, automated perimetry, and fundus photography grading. Patients (n = 165) were enrolled from March 17, 2010, to November 27, 2012, at 38 academic and private practice sites in North America. All participants met the modified Dandy criteria for IIH and had a perimetric mean deviation between −2 dB and −7 dB. All but 4 participants were women. MAIN OUTCOMES AND MEASURES Baseline and laboratory characteristics. RESULTS The mean (SD) age of our patients was 29.0 (7.4) years and 4 (2.4%) were men. The average (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 39.9 (8.3). Headache was the most common symptom (84%). Transient visual obscurations occurred in 68% of patients, back pain in 53%, and pulse synchronous tinnitus in 52%. Only 32% reported visual loss. The average (SD) perimetric mean deviation in the worst eye was −3.5 (1.1) dB, (range, −2.0 to −6.4 dB) and in the best eye was −2.3 (1.1) dB (range, −5.2 to 0.8 dB). A partial arcuate visual field defect with an enlarged blind spot was the most common perimetric finding. Visual acuity was 85 letters or better (20/20) in 71% of the worst eyes and 77% of the best eyes. Quality of life measures, including the National Eye Institute Visual Function Questionnaire–25 and the Short Form–36 physical and mental health summary scales, were lower compared with population norms. CONCLUSIONS AND RELEVANCE The Idiopathic Intracranial Hypertension Treatment Trial represents the largest prospectively analyzed cohort of untreated patients with IIH. Our data show

  11. N-acetylcolchinol O-methyl ether and thiocolchicine, potent analogs of colchicine modified in the C ring. Evaluation of the mechanistic basis for their enhanced biological properties

    SciTech Connect

    Kang, G.J.; Getahun, Z.; Muzaffar, A.; Brossi, A.; Hamel, E. )

    1990-06-25

    Two colchicine analogs with modifications only in the C ring are better inhibitors than colchicine of cell growth and tubulin polymerization. Radiolabeled thiocolchicine (with a thiomethyl instead of a methoxy group at position C-10) and N-acetylcolchinol O-methyl ether (NCME) (with a methoxy-substituted benzenoid instead of the methoxy-substituted tropone C ring) were prepared for comparison with colchicine. Scatchard analysis indicated a single binding site with KD values of 1.0-2.3 microM. Thiocolchicine was bound 2-4 times as rapidly as colchicine, but the activation energies of the reactions were nearly identical (18 kcal/mol for colchicine, 20 kcal/mol for thiocolchicine). NCME bound to tubulin in a biphasic reaction. The faster phase was 60 times as fast as colchicine binding at 37 degrees C, and a substantial reaction occurred at 0 degrees C. The rate of the faster phase of NCME binding changed relatively little as a function of temperature, so the activation energy was only 7.0 kcal/mol. Dissociation reactions were also evaluated, and at 37 degrees C the half-lives of the tubulin-drug complexes were 11 min for NCME, 24 h for thiocolchicine, and 27 h for colchicine. Relative dissociation rates as a function of temperature varied little among the drug complexes. Activation energies for the dissociation reactions were 30 kcal/mol for thiocolchicine, 27 kcal/mol for NCME, and 24 kcal/mol for colchicine. Comparison of the activation energies of association and dissociation yielded free energies for the binding reactions of -20 kcal/mol for NCME, -10 kcal/mol for thiocolchicine, and -6 kcal/mol for colchicine. The greater effectiveness of NCME and thiocolchicine as compared with colchicine in biological assays probably derives from their more rapid binding to tubulin and the lower free energies of their binding reactions.

  12. Musical hallucinations associated with seizures originating from an intracranial aneurysm.

    PubMed

    Roberts, D L; Tatini, U; Zimmerman, R S; Bortz, J J; Sirven, J I

    2001-04-01

    Hallucinations are defined as sensory phenomena in the absence of external sensory stimuli. Auditory hallucinations have been shown to arise from many different intracranial lesions, but seizures manifesting as musical hallucinations triggered by unruptured intracranial aneurysms are rare. We present a case of persistent, episodic musical hallucinations associated with seizures that led to the discovery of 2 small intracranial aneurysms. Typical electroencephalographic findings for seizure activity were observed but resolved after surgical clipping of the aneurysms. Concomitantly, the patient's hallucinations resolved. The literature on musical hallucinations is reviewed. PMID:11322359

  13. Intracranial hypertension: was it really idiopathic?

    PubMed

    Williams, Manon Wyn; Vishwanath, Mandagere

    2011-01-01

    A healthy 44-year-old slim female presented with a constant, non-specific dull headache of subacute onset. The examination showed papilloedema but no other problem. On further questioning she revealed transient visual obscurations and pulsatile tinnitus. The CT scan of the brain was normal, the lumbar puncture showed increased pressure but normal cerebrospinal fluid, and the MR scan and MR venogram was reported showing a small area of developmental venous anomaly in the left parietal region but no venous thrombosis. Benign intracranial hypertension (BIH) was diagnosed but later in the course further tests were done as the patient was atypical for BIH, which revealed essential thrombocythaemia. A CT venogram was arranged which showed partly recanalised chronic sigmoid sinus thrombosis with dilation of collaterals. The patient was treated with acetazolamide, wafarin and hydroxycarbamide. The headache resolved quickly and the papilloedema reduced significantly over 6 months. PMID:22696634

  14. Chronic inflammatory demyelinating polyradiculoneuropathy associated intracranial hypertension.

    PubMed

    Altinkaya, Ayca; Topcular, Baris; Sakalli, Nazan Karagoz; Kuscu, Demet Yandim; Kirbas, Dursun

    2013-06-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired immune-mediated demyelinating neuropathy. In this report, we detail the course of a 58-year-old male patient who had headache and double vision followed by progressive paresthesia and difficulty in walking. The patient had bilateral papilledema and mild leg weakness, absent ankle jerks and loss of sensation in distal parts of his lower and upper extremities. His electromyography (EMG) was concordant with CIDP and lumbar puncture revealed high opening pressure. The polyradiculoneuropathy as well as the papilledema and elevated cerebrospinal fluid (CSF) pressure improved under steroids. The improvement in intracranial hypertension (IHT) and papilledema under steroid treatment suggests that the IHT in this patient might be associated with CIDP.

  15. Intracranial Infectious Aneurysm in Orbital Cellulitis.

    PubMed

    Lee, Brian; Kim, Charles; Carrasco, Jacqueline

    2015-01-01

    Infectious intracranial aneurysm and cavernous sinus thrombosis are rare complications of orbital cellulitis. We report the case of a 46-year-old male presenting with sinusitis and orbital cellulitis complicated by the development of an orbital mass. Following orbitotomy with debulking, the patient underwent bony orbital decompression for increasing proptosis postoperatively. While his exam stabilized, the patient developed complete ptosis and extraocular motor palsy in the contralateral eye after undergoing bilateral sinus debridement. Imaging was notable for the presence of a pseudoaneurysm of the internal carotid artery, which was treated with a stent. This report demonstrates rare complications of orbital cellulitis. These patients should be monitored carefully with noninvasive imaging studies, such as cerebral angiography, for early detection of vascular abnormalities that can progress rapidly. PMID:25955309

  16. Intracranial meningeal chondrosarcoma--probable mesenchymal type.

    PubMed

    Rodda, R A; Franklin, C I

    1984-08-01

    A 12 year old girl with episodes of left hemiparesis for 9 months was found to have a large, partly calcified brain tumour which at craniotomy presented on the parasagittal and medial surfaces of the right frontal lobe. No dural or falx attachment could be found and naked eye removal of the tumour was achieved. At a second craniotomy 10 weeks later there was recurrent tumour attached to the falx and involving the sagittal sinus. She died 5 months later. Pathologically, almost all this malignant intracranial neoplasm comprised differentiated cartilaginous tumour. Although only a very small amount of undifferentiated mesenchymal tissue was found in the surgical material available for histological study, it is suggested the tumour can be regarded as a predominantly mature mesenchymal chondrosarcoma of the meninges.

  17. Surgical Management of Intracranial Artery Dissection

    PubMed Central

    ARIMURA, Koichi; IIHARA, Koji

    2016-01-01

    Intracranial artery dissection (IAD) is a relatively rare cause of stroke, but it has been recognized increasingly with recent advances of the neuroimaging technique. Since rebleeding occurs frequently in the acute stage in the ruptured IAD, urgent surgical treatment should be performed to prevent rebleeding. On the other hand, surgical treatment for unruptured IAD is controversial because it has little risk for bleeding. However, surgical treatment for unruptured IAD may be considered if the formation or enlargement of the aneurysmal dilatation has been confirmed. Since there are several proposed surgical strategies for IAD, it is important to select an appropriate strategy on a case-by-case basis. If the risk of infarction due to vessel occlusion is high, combined bypass surgery should be considered. PMID:27063145

  18. New Faint Ring-Like Structures Found in Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Ramos-Larios, G.; Santamaría, E.; Marquez-Lugo, A.; Guerrero, M. A.; Sabin, L.

    2014-04-01

    Many PNe show rings and shells related to the remnants of the circumstellar envelopes of the asymptotic giant branch phase (AGB). After an extensive search in the HST and Spitzer archives we found ring-like structures in several PNe. Following the image analysis described by Corradi et al. (2004), and unsharp masking techniques it was possible to effectively remove the underlying halo emission, enhancing the ring structures. We mention in the results some hypotheses about the origins of these rings.

  19. Management of Intracranial Meningiomas Using Keyhole Techniques

    PubMed Central

    Burks, Joshua D; Conner, Andrew K; Bonney, Phillip A; Archer, Jacob B; Christensen, Blake; Smith, Jacqueline; Safavi-Abbasi, Sam

    2016-01-01

    Background: Keyhole craniotomies are increasingly being used for lesions of the skull base. Here we review our recent experience with these approaches for resection of intracranial meningiomas. Methods: Clinical and operative data were gathered on all patients treated with keyhole approaches by the senior author from January 2012 to June 2013. Thirty-one meningiomas were resected in 27 patients, including 9 supratentorial, 5 anterior fossa, 7 middle fossa, 6 posterior fossa, and 4 complex skull base tumors. Twenty-nine tumors were WHO Grade I, and 2 were Grade II.  Results: The mean operative time was 8 hours, 22 minutes (range, 2:55-16:14) for skull-base tumors, and 4 hours, 27 minutes (range, 1:45-7:13) for supratentorial tumors. Simpson Resection grades were as follows: Grade I = 8, II = 8, III = 1, IV = 15, V = 0. The median postoperative hospital stay was 4 days (range, 1-20 days). In the 9 patients presenting with some degree of visual loss, 7 saw improvement or complete resolution. In the 6 patients presenting with cranial nerve palsies, 4 experienced improvement or resolution of the deficit postoperatively. Four patients experienced new neurologic deficits, all of which were improved or resolved at the time of the last follow-up. Technical aspects and surgical nuances of these approaches for management of intracranial meningiomas are discussed.  Conclusions: With careful preoperative evaluation, keyhole approaches can be utilized singly or in combination to manage meningiomas in a wide variety of locations with satisfactory results. PMID:27284496

  20. Visual Impairment/Intracranial Pressure Risk Assessment

    NASA Technical Reports Server (NTRS)

    Fogarty, Jennifer A.; Durham, T.; Otto, C.; Grounds, D.; Davis, J. R.

    2010-01-01

    Since 2006 there have been 6 reported cases of altered visual acuity and intracranial pressure (ICP) in long duration astronauts. In order to document this risk and develop an integrated approach to its mitigation, the NASA Space Life Sciences Directorate (SLSD) and Human Research Program (HRP) have chosen to use the Human System Risk Board (HSRB) and the risk management analysis tool (RMAT). The HSRB is the venue in which the stakeholders and customers discuss and vet the evidence and the RMAT is the tool that facilitates documentation and comparison of the evidence across mission profiles as well as identification of risk factors, and documentation of mitigation strategies. This process allows for information to be brought forward and dispositioned so that it may be properly incorporated into the RMAT and contribute to the design of the research and mitigation plans. The evidence thus far has resulted in the identification of a visual impairment/intracranial pressure (VIIP) project team, updating of both short and long duration medical requirements designed to assess visual acuity, and a research plan to characterize this issue further. In order to understand this issue more completely, a plan to develop an Accelerated Research Collaboration (ARC) has been approved by the HSRB. The ARC is a novel research model pioneered by the Myelin Repair Foundation. It is a patient centered research model that brings together researchers and clinicians, under the guidance of a scientific advisory panel, to collaborate and produce results much quickly than accomplished through traditional research models. The data and evidence from the updated medical requirements and the VIIP ARC will be reviewed at the HSRB on a regular basis. Each review package presented to the HSRB will include an assessment and recommendation with respect to continuation of research, countermeasure development, occupational surveillance modalities, selection criteria, etc. This process will determine the

  1. Endoscope-Assisted Microneurosurgery for Intracranial Aneurysms

    PubMed Central

    Galzio, Renato J.; Di Cola, Francesco; Raysi Dehcordi, Soheila; Ricci, Alessandro; De Paulis, Danilo

    2013-01-01

    Background: The endovascular techniques has widely changed the treatment of intracranial aneurysms. However surgery still represent the best therapeutic option in case of broad-based and complex lesions. The combined use of endoscopic and microsurgical techniques (EAM) may improve surgical results. Objective: The purpose of our study is to evaluate the advantages and limits of EAM for intracranial aneurysms. Methods: Between January 2002 and December 2012, 173 patients, harboring 206 aneurysms were surgically treated in our department with the EAM technique. One hundred and fifty-seven aneurysms were located in the anterior circulation and 49 were in the posterior circulation. Standard tailored approaches, based on skull base surgery principles, were chosen. The use of the endoscope included three steps: initial inspection, true operative time, and final inspection. For each procedure, an intraoperative video and an evaluation schedule were prepared, to report surgeons’ opinions about the technique itself. In the first cases, we always used the endoscope during surgical procedures in order to get an adequate surgical training. Afterwards we became aware in selecting cases in which to apply the endoscopy, as we started to become familiar with its advantages and limits. Results: After clipping, all patients were undergone postoperative cerebral angiography. No surgical mortality related to EAM were observed. Complications directly related to endoscopic procedures were rare. Conclusion: Our retrospective study suggests that endoscopic efficacy for aneurysms is only scarcely influenced by the preoperative clinical condition (Hunt–Hess grade), surgical timing, presence of blood in the cisterns (Fisher grade) and/or hydrocephalus. However the most important factors contributing to the efficacy of EAM are determined by the anatomical locations and sizes of the lesions. Furthermore, the advantages are especially evident using dedicated scopes and holders, after an

  2. Vascular ring (image)

    MedlinePlus

    Vascular ring is a term used to describe a number of abnormal formations of the aorta, the large artery ... the pulmonary artery. The abnormal vessel(s) forms a ring, which encircles and may press down on the ...

  3. New dust belts of Uranus: one ring, two ring, red ring, blue ring.

    PubMed

    de Pater, Imke; Hammel, Heidi B; Gibbard, Seran G; Showalter, Mark R

    2006-04-01

    We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G ring, which is red, a typical color for dusty rings. PMID:16601188

  4. New dust belts of Uranus: one ring, two ring, red ring, blue ring.

    PubMed

    de Pater, Imke; Hammel, Heidi B; Gibbard, Seran G; Showalter, Mark R

    2006-04-01

    We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G ring, which is red, a typical color for dusty rings.

  5. Successfully Treated Isolated Posterior Spinal Artery Aneurysm Causing Intracranial Subarachnoid Hemorrhage: Case Report

    PubMed Central

    HORIO, Yoshinobu; KATSUTA, Toshiro; SAMURA, Kazuhiro; WAKUTA, Naoki; FUKUDA, Kenji; HIGASHI, Toshio; INOUE, Tooru

    2015-01-01

    There are very few published reports of rupture of an isolated posterior spinal artery (PSA) aneurysm, and consequently the optimal therapeutic strategy is debatable. An 84-year-old man presented with sudden onset of restlessness and disorientation. Neuroradiological imaging showed an intracranial subarachnoid hemorrhage (SAH) with no visible intracranial vascular lesion. Spinal magnetic resonance imaging (MRI) detected a localized subarachnoid hematoma at Th10–11. Both contrast-enhanced spinal computed tomography and enhanced MRI and magnetic resonance angiography revealed an area of enhancement within the hematoma. Superselective angiography of the left Th12 intercostal artery demonstrated a faintly enhanced spot in the venous phase. Thirteen days after the onset of symptoms, a small fusiform aneurysm situated on the radiculopial artery was resected. The patient's postoperative course was uneventful and he was eventually discharged in an ambulatory condition. To our knowledge, this 84-year-old man is the oldest reported case of surgical management of a ruptured isolated PSA aneurysm. This case illustrates both the validity and efficacy of this therapeutic approach. PMID:26522607

  6. Saturn's F-Ring

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This narrow-angle camera image of Saturn's F Ring was taken through the Clear filter while at a distance of 6.9 million km from Saturn on 8 November 1980. The brightness variations of this tightly-constrained ring shown here indicate that the ring is less uniform in makeup than the larger rings. JPL managed the Voyager Project for NASA's Office of Space Science

  7. Cyclooxygenase-2 (COX-2) expression in canine intracranial meningiomas.

    PubMed

    Rossmeisl, J H; Robertson, J L; Zimmerman, K L; Higgins, M A; Geiger, D A

    2009-09-01

    Meningiomas are the most common canine intracranial tumour. Neurologic disability and death from treatment failure remain problematic despite current surgical and radiotherapeutic treatments for canine intracranial meningiomas. Cyclooxygenase-2 (COX-2) over-expression has been demonstrated in multiple canine malignancies, and COX-2 inhibitory treatment strategies have been shown to have both preventative and therapeutic effects in spontaneous and experimental models of cancer. The purpose of this study was to evaluate COX-2 expression in canine intracranial meningiomas. Immunohistochemical and Western blot (WB) analyses showed COX-2 expression in multiple tissues of the normal canine brain, and 87% (21/24) of intracranial meningiomas studied were immunoreactive to COX-2. No significant associations between COX-2 immunoreactivity and tumour grade were identified. Further studies are required to elucidate the physiologic roles of constitutive COX-2 expression in the central nervous system as well as its participation in meningioma tumourigenesis. PMID:19691646

  8. [Prolonged hypothermia in refractory intracranial hypertension. Report of one case].

    PubMed

    Rovegno, Maximiliano; Valenzuela, José Luis; Mellado, Patricio; Andresen, Max

    2012-02-01

    The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies. PMID:22739952

  9. The Jumping Ring Experiment

    ERIC Educational Resources Information Center

    Baylie, M.; Ford, P. J.; Mathlin, G. P.; Palmer, C.

    2009-01-01

    The jumping ring experiment has become central to liquid nitrogen shows given as part of the outreach and open day activities carried out within the University of Bath. The basic principles of the experiment are described as well as the effect of changing the geometry of the rings and their metallurgical state. In general, aluminium rings are…

  10. Rings Around Uranus

    ERIC Educational Resources Information Center

    Maran, Stephen P.

    1977-01-01

    Events leading up to the discovery of the rings of Uranus are described. The methods used and the logic behind the methods are explained. Data collected to prove the existence of the rings are outlined and theories concerning the presence of planetary rings are presented. (AJ)

  11. Imaging Modalities Relevant to Intracranial Pressure Assessment in Astronauts

    NASA Technical Reports Server (NTRS)

    Sargsyan, Ashot E.; Kramer, Larry A.; Hamilton, Douglas R.; Fogarty, Jennifer; Polk, J. D.

    2011-01-01

    Learning Objectives of this slide presentation are: 1: To review the morphological changes in orbit structures caused by elevated Intracranial Pressure (ICP), and their imaging representation. 2: To learn about the similarities and differences between MRI and sonographic imaging of the eye and orbit. 3: To learn about the role of MRI and sonography in the noninvasive assessment of intracranial pressure in aerospace medicine, and the added benefits from their combined interpretation.

  12. Intracranial saccular aneurysm in a child with only persistent headache.

    PubMed

    Güngör, Olcay; Özkaya, Ahmet Kağan; Dilber, Cengiz; Çinar, Celal

    2015-06-01

    Headache is one of the common symptoms of intracranial aneursym. A 5-year-old child lately presented to our pediatric emergency department with persistent headache. Brain magnetic resonance imaging revealed a 7×8 mm rounded lesion with slowly heterogeneous low signal in T2 sequence consistent with a partial occluded aneurysm, in the right medial frontal lobe that close to anterior cerebral artery. Intracranial aneurysms are rare in children and they are noncommon without complications as our case.

  13. Intracranial subdural empyema mimicking a recurrent chronic subdural hematoma

    PubMed Central

    Doan, Ninh; Patel, Mohit; Nguyen, Ha Son; Mountoure, Andrew; Shabani, Saman; Gelsomino, Michael; Janich, Karl; Kurpad, Shekar

    2016-01-01

    Intracranial subdural empyema (ISDE) is a life-threatening condition. The risk for ISDE increases in patients that have undergone prior intracranial procedures. The non-specificity in its clinical presentation often makes ISDE difficult to diagnose. Here, we present a rare case of ISDE mimicking a recurrent chronic subdural hematoma, emphasizing the significance of obtaining early magnetic resonance images of the brain for early diagnosis and treatment to achieve the optimal outcome. PMID:27651110

  14. Intracranial subdural empyema mimicking a recurrent chronic subdural hematoma.

    PubMed

    Doan, Ninh; Patel, Mohit; Nguyen, Ha Son; Mountoure, Andrew; Shabani, Saman; Gelsomino, Michael; Janich, Karl; Kurpad, Shekar

    2016-01-01

    Intracranial subdural empyema (ISDE) is a life-threatening condition. The risk for ISDE increases in patients that have undergone prior intracranial procedures. The non-specificity in its clinical presentation often makes ISDE difficult to diagnose. Here, we present a rare case of ISDE mimicking a recurrent chronic subdural hematoma, emphasizing the significance of obtaining early magnetic resonance images of the brain for early diagnosis and treatment to achieve the optimal outcome. PMID:27651110

  15. Traumatic aneurysms of the intracranial and cervical vessels: A review.

    PubMed

    Bhaisora, Kamlesh S; Behari, Sanjay; Godbole, Chaitanya; Phadke, Rajendra V

    2016-01-01

    Traumatic intracranial aneurysms (TICA) are rare in occurrence, constituting less than 1% of the total cases of intracranial aneurysms. Cervical posttraumatic aneurysms arising from major blood vessels supplying the brain are also extremely rare. Their variable locations, morphological variations and the presence of concomitant head injury makes their diagnosis and treatment a challenge. In this review, we discuss the epidemiology, etiology, classification and management issues related to TICA as well as traumatic neck aneurysms and review the pertinent literature.

  16. Chronic Meningitis Complicating Intracranial Hypertension in Neurobrucellosis: A Case Report.

    PubMed

    Tugcu, Betul; Nacaroglu, Senay Asik; Coskun, Cigdem; Kuscu, Demet Yandım; Onder, Feyza

    2015-01-01

    In neurobrucellosis, even though meningitis is encountered frequently, chronic intracranial hypertension is a rare manifestation. Early diagnosis and treatment is very important for the prevention of permanent visual loss secondary to poststasis optic atrophy in these cases. We report a case that presented with permanent visual loss secondary to intracranial hypertension in neurobrucellosis. Our goal is to draw attention to the consideration of neurobrucellosis in cases with papilla stasis, even in the absence of neurological findings in endemic areas.

  17. Intracranial subdural empyema mimicking a recurrent chronic subdural hematoma

    PubMed Central

    Doan, Ninh; Patel, Mohit; Nguyen, Ha Son; Mountoure, Andrew; Shabani, Saman; Gelsomino, Michael; Janich, Karl; Kurpad, Shekar

    2016-01-01

    Intracranial subdural empyema (ISDE) is a life-threatening condition. The risk for ISDE increases in patients that have undergone prior intracranial procedures. The non-specificity in its clinical presentation often makes ISDE difficult to diagnose. Here, we present a rare case of ISDE mimicking a recurrent chronic subdural hematoma, emphasizing the significance of obtaining early magnetic resonance images of the brain for early diagnosis and treatment to achieve the optimal outcome.

  18. Emergency Neurological Life Support: Intracranial Hypertension and Herniation

    PubMed Central

    Shoykhet, Michael; Cadena, Rhonda

    2016-01-01

    Sustained intracranial hypertension and acute brain herniation are “brain codes,” signifying catastrophic neurological events that require immediate recognition and treatment to prevent irreversible injury and death. As in cardiac arrest, a brain code mandates the organized implementation of a stepwise management algorithm. The goal of this emergency neurological life support protocol is to implement an evidence-based, standardized approach to the evaluation and management of patients with intracranial hypertension and/or herniation. PMID:26438459

  19. Intracranial pressure waveform analysis: clinical and research implications.

    PubMed

    Kirkness, C J; Mitchell, P H; Burr, R L; March, K S; Newell, D W

    2000-10-01

    Assessment of intracranial adaptive capacity is vital in critically ill individuals with acute brain injury because there is the potential that nursing care activities and environmental stimuli to result in clinically significant increases in intracranial pressure (ICP) in a subset of individuals with decreased intracranial adaptive capacity. ICP waveform analysis provides information about intracranial dynamics that can help identify individuals who have decreased adaptive capacity and are at risk for increases in ICP and decreases in cerebral perfusion pressure, which may contribute to secondary brain injury and have a negative impact on neurologic outcome. The ability to identify high-risk individuals allows nurses to initiate interventions targeted at decreasing adaptive demand or increasing adaptive capacity in these individuals. Changes in the ICP waveform occur under various physiologic and pathophysiologic conditions and may provide valuable information about intracranial adaptive capacity. Simple visual assessment of the ICP waveform for increased amplitude and P2 elevation is clinically relevant and has been found to provide a rough indicator of decreased adaptive capacity. Advanced ICP waveform analysis techniques warrant further study as a means of dynamically assessing intracranial adaptive capacity.

  20. Traumatic Intracranial Aneurysm Formation following Closed Head Injury

    PubMed Central

    Miley, Jefferson T; Rodriguez, Gustavo J; Qureshi, Adnan I

    2008-01-01

    Background: Traumatic intracranial aneurysms are rare conditions that can be a result of non-penetrating head trauma. We report the occurrence of intracranial aneurysms in patients with traumatic brain injury. Methods: All diagnostic cerebral angiograms performed in patients with traumatic brain injury at a level I trauma center from January 2006 to July 2007 were reviewed. Results: Diagnostic cerebral angiography was performed in 74 patients with the diagnosis of closed head injury. A total of 4 traumatic intracranial pseudoaneurysms were found in 4 patients, two in the supraclinoid segment of the internal carotid artery, one in the cavernous segment of the internal carotid artery and one in the paraophthalmic segment of the internal carotid artery. Two patients were treated with coil embolization. One patient had follow up imaging on which there was no change in the size and morphology of the aneurysm. Conclusion: Intracranial aneurysms can develop in patients with closed head injury presumably related to shear or rotational injury. It is unclear whether these aneurysms should be classified as traumatic intracranial aneurysms or pseudoaneurysms, but the pathological findings frequently reveal disruption of the three vascular layers fulfilling the definition of pseudoaneurysm. For these reason we favor the name of post-traumatic intracranial pseudoaneurysms. PMID:22518228

  1. Saturn's largest ring.

    PubMed

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

    2009-10-22

    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

  2. Dust and Planetary Rings

    NASA Astrophysics Data System (ADS)

    Siddiqui, Muddassir

    ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring

  3. Intracranial nonthermal irreversible electroporation: in vivo analysis.

    PubMed

    Garcia, Paulo A; Rossmeisl, John H; Neal, Robert E; Ellis, Thomas L; Olson, John D; Henao-Guerrero, Natalia; Robertson, John; Davalos, Rafael V

    2010-07-01

    Nonthermal irreversible electroporation (NTIRE) is a new minimally invasive technique to treat cancer. It is unique because of its nonthermal mechanism of tumor ablation. Intracranial NTIRE procedures involve placing electrodes into the targeted area of the brain and delivering a series of short but intense electric pulses. The electric pulses induce irreversible structural changes in cell membranes, leading to cell death. We correlated NTIRE lesion volumes in normal brain tissue with electric field distributions from comprehensive numerical models. The electrical conductivity of brain tissue was extrapolated from the measured in vivo data and the numerical models. Using this, we present results on the electric field threshold necessary to induce NTIRE lesions (495-510 V/cm) in canine brain tissue using 90 50-mus pulses at 4 Hz. Furthermore, this preliminary study provides some of the necessary numerical tools for using NTIRE as a brain cancer treatment. We also computed the electrical conductivity of brain tissue from the in vivo data (0.12-0.30 S/m) and provide guidelines for treatment planning and execution. Knowledge of the dynamic electrical conductivity of the tissue and electric field that correlates to lesion volume is crucial to ensure predictable complete NTIRE treatment while minimizing damage to surrounding healthy tissue. PMID:20668843

  4. Parent Artery Occlusion for Intracranial Aneurysms

    PubMed Central

    Cui, Lishan; Peng, Qiang; Ha, Wenbo; Zhou, Dexiang; Xu, Yang

    2009-01-01

    Summary Peripheral cerebral aneurysms are difficult to treat with preservation of the parent arteries. We report the clinical and angiographic outcome of 12 patients with cerebral aneurysms located peripherally. In the past five years, 12 patients, six females and six males, presented at our institution with intracranial aneurysms distal to the circle of Willis and were treated endovascularly. The age of our patients ranged from four to 58 years with a mean age of 37 years. Seven of the 12 patients had subarachnoid and/or intracerebral hemorrhage upon presentation. Two patients with P2 dissecting aneurysms presented with mild hemiparesis and hypoesthesia, one patient with a large dissecting aneurysm complained of headaches and two patients with M3 dissecting aneurysms had mild hemiparesis and hypoesthesia of the right arm. Locations of the aneurysms were as follows: posterior cerebral artery in seven patients, anterior inferior cerebellar artery in two, posterior inferior cerebellar artery in one, middle cerebral artery in two. Twelve patients with peripheral cerebral aneurysms underwent parent artery occlusion (PAO). PAO was performed with detachable coils. No patient developed neurologic deficits. Distally located cerebral aneurysms can be treated with parent artery occlusion when selective embolization of the aneurysmal sac with detachable platinum coils or surgical clipping cannot be achieved. PMID:20465914

  5. [Intracranial pressure and hypotonic infusion solutions].

    PubMed

    Zander, R

    2009-04-01

    The physiological osmolality of plasma is 288+/-5 mosmol/kgH2O when measured by freezing-point depression. The theoretical osmolarity (290 mosmol/l) calculated from composition, osmotic coefficient (0.93) and water content (0.94) is practically identical. Saline (0.9% NaCl) has an osmolarity of 308 mosmol/l and an osmolality of 286 mosmol/kgH2O (water content ca. 1.0). The osmolality in vivo is more important than that measured in vitro. A 5% dextrose solution in water (D5W) is isotonic in vitro, but the in vivo effect is that of pure water because the glucose is rapidly metabolized. Every infusion fluid should be isotonic (290+/-10 mosmol/kgH2O). Hypotonic solutions must move water from the extracellular space to the intracellular space. Typical examples are Ringer's lactate and acetate solutions (256 instead of 290 mosmol/kgH2O). The brain (central nervous system, CNS) is the critical organ: The rigidly shaped skull contains three incompressible compartments, only blood and cerebrospinal fluid (CSF) can be partially, but limitedly shifted outside the skull. The consequence of a volume load is an increasing intracranial pressure (ICP). A decrease in plasma osmolality by only 3% produces an increase in ICP of about 15 mmHg. Therefore, infusion of larger volumes of hypotonic solutions should be avoided at all costs.

  6. Potential for intracranial movements in pterosaurs.

    PubMed

    Prondvai, Edina; Osi, Attila

    2011-05-01

    Based on comparative anatomical, morphological, and phylogenetic considerations the potential of pterosaurs for cranial kinesis is assessed. Our investigation shows that whereas skeletally mature derived pterodactyloids have completely fused, rigid and doubtlessly akinetic skulls, skeletally immature derived pterodactyloids and more basal pterosaurs possess key features in the morphology of their otic and basal joints that are suggestive of cranial kinesis, namely streptostyly. In addition, pterosaurs exhibit an evolutionarily informative trend in the degree of cranial ossification, where it is low in most nonpterodactyloids (here named bifenestratans), intermediate in Rhamphorhynchus and Archaeopterodactyloidea, and high in derived pterodactyloids. Incomplete fusion could also indicate loose connections between skull elements. However, another crucial anatomical requirement of a kinetic skull, the permissive kinematic linkage is absent in all pterosaurian taxa. The fact, that the presence of permissive kinematic linkages in the skull is also a prerequisite of all types of cranial kinesis, provides hard evidence that all members of Pterosauria had akinetic skulls. Thus, the presence of the morphological attributes indicative of intracranial movements in some pterosaurs must be explained on grounds other than real potential for cranial kinesis. It could either be of mechanical or ontogenetic importance, or both. Alternatively, it might be considered as the morphological remnant of a real, kinetic skull possessed by the diapsid ancestors of pterosaurs.

  7. Potential for intracranial movements in pterosaurs.

    PubMed

    Prondvai, Edina; Osi, Attila

    2011-05-01

    Based on comparative anatomical, morphological, and phylogenetic considerations the potential of pterosaurs for cranial kinesis is assessed. Our investigation shows that whereas skeletally mature derived pterodactyloids have completely fused, rigid and doubtlessly akinetic skulls, skeletally immature derived pterodactyloids and more basal pterosaurs possess key features in the morphology of their otic and basal joints that are suggestive of cranial kinesis, namely streptostyly. In addition, pterosaurs exhibit an evolutionarily informative trend in the degree of cranial ossification, where it is low in most nonpterodactyloids (here named bifenestratans), intermediate in Rhamphorhynchus and Archaeopterodactyloidea, and high in derived pterodactyloids. Incomplete fusion could also indicate loose connections between skull elements. However, another crucial anatomical requirement of a kinetic skull, the permissive kinematic linkage is absent in all pterosaurian taxa. The fact, that the presence of permissive kinematic linkages in the skull is also a prerequisite of all types of cranial kinesis, provides hard evidence that all members of Pterosauria had akinetic skulls. Thus, the presence of the morphological attributes indicative of intracranial movements in some pterosaurs must be explained on grounds other than real potential for cranial kinesis. It could either be of mechanical or ontogenetic importance, or both. Alternatively, it might be considered as the morphological remnant of a real, kinetic skull possessed by the diapsid ancestors of pterosaurs. PMID:21455955

  8. High-Speed Ring Bus

    NASA Technical Reports Server (NTRS)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  9. On multiple Einstein rings

    NASA Astrophysics Data System (ADS)

    Werner, M. C.; An, J.; Evans, N. W.

    2008-12-01

    A number of recent surveys for gravitational lenses have found examples of double Einstein rings. Here, we analytically investigate the occurrence of multiple Einstein rings. We prove, under very general assumptions, that at the most one Einstein ring can arise from a mass distribution in a single plane lensing a single background source. Two or more Einstein rings can therefore only occur in multiplane lensing. Surprisingly, we show that it is possible for a single source to produce more than one Einstein ring. If two point masses, or two isothermal spheres, in different planes are aligned with observer and source on the optical axis, we show that there are up to three Einstein rings. We also discuss the image morphologies for these two models if axisymmetry is broken, and give the first instances of magnification invariants in the case of two-lens planes.

  10. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  11. Is neuroradiological imaging sufficient for exclusion of intracranial hypertension in children? Intracranial hypertension syndrome without evident radiological symptoms.

    PubMed

    Larysz, Dawid; Larysz, Patrycja; Klimczak, Andrzej; Mandera, Marek

    2010-01-01

    There are still many important questions about algorithms and clinical scenarios in the context of children with clinical intracranial hypertension symptoms (IHS) without radiological findings. Such conditions could appear in different clinical situations, including slit ventricle syndrome, overdrainage syndrome, normal volume hydrocephalus, or idiopathic intracranial hypertension. Many articles have defined specific treatment strategies for various forms of IHS, including ventriculoperitoneal shunting, medication for shunt-related migraine, steroids, and valve upgrades with antisiphoning devices or programmable systems. This study is an attempt to define the proper diagnostic procedures and treatment options for patients with various forms of IHS without evident neuroradiological findings. The authors discuss possible pathological mechanisms leading to IHS in the pediatric population. The authors present six children treated in their center. All of the children presented clinical manifestation of intracranial hypertension without evident neuroradiological findings in CT and/or MRI examinations. In three cases, the final diagnosis was slit ventricle syndrome; in two cases, normal volume hydrocephalus; in another case, idiopathic intracranial hypertension. The treatment options included short-term steroid (dexamethasone) administration and ventriculoperitoneal shunting using programmable systems. In one case of idiopathic intracranial hypertension, ICP monitoring was also performed. The authors discuss possible diagnostic and treatment strategies for the aforementioned cases. There are still many controversies about management of children with clinical symptoms of intracranial hypertension that are not confirmed in neuroimaging. It seems that our understanding of intracranial hypertension in the pediatric population is not nearly as sophisticated or complete as we might have imagined. Ventriculoperitoneal shunting with antisiphoning devices and/or short

  12. Temperatures of Saturn's rings.

    NASA Technical Reports Server (NTRS)

    Murphy, R. E.

    1973-01-01

    The 20-micron brightness temperatures of the rings were determined using the 224-cm telescope of the Mauna Kea Observatory, and the standard University of Hawaii radiometer with a 17- to 25-micron filter. The observations were made on the nights of Aug. 20 and 21, and Sept. 26 and 27, 1972. The brightness temperatures of the A, B, and C rings are, respectively, 89 plus or minus 3 K, 94 plus or minus 2 K, and 89 plus or minus 4 K. A possible explanation of the relatively high temperature of the C ring is that Saturn has radiation belts and the inner ring is heated by particle bombardment.

  13. Superficial siderosis is a warning sign for future intracranial hemorrhage.

    PubMed

    Linn, Jennifer; Wollenweber, Frank A; Lummel, Nina; Bochmann, Katja; Pfefferkorn, Thomas; Gschwendtner, Andreas; Bruckmann, Hartmut; Dichgans, Martin; Opherk, Christian

    2013-01-01

    Supratentorial superficial siderosis (SS) is a frequent imaging marker of cerebral amyloid angiopathy (CAA). It is most probably caused by focal subarachnoid hemorrhages (fSAHs). Based on single-case observations, it has been proposed that such fSAHs might be a predisposing factor for future intracranial hemorrhage. Here we tested the hypothesis if a SS as a residue of fSAHs must be regarded as a warning sign for future intracranial hemorrhage. Fifty-one consecutive patients with SS and no apparent cause other than possible or probable CAA were identified through a database search and followed-up for a median interval of 35.3 months (range 6-120 months). Main outcome measures were rate and location of new intracranial hemorrhages. Twenty-four patients (47.1 %) had experienced any new intracranial hemorrhage, 18 patients (35.3 %) had an intracerebral hemorrhage (ICH), and in 13 of them (25.5 %), the hemorrhage was located at the site of pre-existing siderosis. Six patients (11.7 %) had developed a new subarachnoid hemorrhage (SAH), four of them at the site of siderosis. Patients with SS are at substantial risk for subsequent intracranial hemorrhage. SS can be considered a warning sign of future ICH or SAH, which frequently occur adjacent to pre-existing SS. Prospective studies are needed to confirm these findings.

  14. The Management of Intracranial Aneurysms During Pregnancy: A Systematic Review.

    PubMed

    Barbarite, Eric; Hussain, Shahrose; Dellarole, Anna; Elhammady, Mohamed Samy; Peterson, Eric

    2016-01-01

    Hemodynamic changes during pregnancy may favor the formation and rupture of intracranial aneurysms. Despite this risk, guidelines for managing intracranial aneurysms during pregnancy have not been clearly defined. The objective of this review is to describe the treatment options for pregnant women with intracranial aneurysms, and to report the maternal and fetal outcomes associated with different treatment strategies. A search of the literature was conducted using the PubMed database for the period January 1991 through June 2015. Aneurysm characteristics and management, pregnancy management, and maternal and fetal outcomes were evaluated. The most recent search was performed in June 2015. In total, 50 aneurysms (44 patients) were evaluated. Rupture was confirmed upon imaging in 36 aneurysms (72%), and most aneurysms ruptured during the third trimester (77.8%). Coil embolization was associated with a lower complication rate than clipping in patients with ruptured aneurysms (9.5% vs 23.1%). For patients with unruptured aneurysms, surgical management was associated with 31.9% fewer complications compared to no treatment. Most patients underwent Cesarean delivery (84%), and a combined neurosurgical-obstetrical procedure was used for 8 patients with ruptured aneurysms near term. Adverse outcomes were reported in 11.9% of children. Treatment of intracranial aneurysms during pregnancy is safe and effective. Furthermore, we suggest that coil embolization be considered a first line treatment over clipping for surgical management of the pregnant population. Going forward, we encourage the establishment of formal guidelines for managing intracranial aneurysms during pregnancy. PMID:27400091

  15. Micro packaged MEMS pressure sensor for intracranial pressure measurement

    NASA Astrophysics Data System (ADS)

    Xiong, Liu; Yan, Yao; Jiahao, Ma; Yanhang, Zhang; Qian, Wang; Zhaohua, Zhang; Tianling, Ren

    2015-06-01

    This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Miniaturization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm2. It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm2. In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm2. Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10-2 mV/kPa. Project supported by the National Natural Science Foundation of China (Nos. 61025021, 61434001), and the ‘Thousands Talents’ Program for Pioneer Researchers and Its Innovation Team, China.

  16. Cervical Myelopathy Caused by Intracranial Dural Arteriovenous Fistula

    PubMed Central

    Kim, Won Young; Kim, Jin Bum; Nam, Taek Kyun; Kim, Young Baeg

    2016-01-01

    Intracranial dural arteriovenous fistula (dAVF) usually results in various problems in the brain. But it can be presented as a myelopathy, which may make early diagnosis and management to be difficult. We recently experienced a case of cervical myelopathy caused by intracranial dAVF. A 60-year-old man presented with a 3-year history of gait disturbance due to a progressive weakness of both legs. Neurological examination revealed spastic paraparesis (grade IV) and Babinski sign on both sides. Magnetic resonance imaging showed serpentine vascular signal voids at C2-T1 on T2-weighted image with increased signal intensity and swelling of spinal cord at C1-C4. We performed a brain computed tomography angiography and found intracranial dAVF with multiple arteriovenous shunts. Venous drainages were noted at tentorial veins and cervical perimedullary veins. After Onyx embolization, the patient showed gradual improvement in motor power and gait disturbance. The venous drainage pattern is a well-known prognostic factor of dAVF. In our case, the intracranial dAVF drained to spinal perimedullary vein, which seemed to result in the ischemic myelopathy. Although it is rare condition, it sometimes can cause serious complications. Therefore, we should keep in mind the possibility of intracranial dAVF when a patient presents myelopathy. PMID:27437016

  17. Cervical Myelopathy Caused by Intracranial Dural Arteriovenous Fistula.

    PubMed

    Kim, Won Young; Kim, Jin Bum; Nam, Taek Kyun; Kim, Young Baeg; Park, Seung Won

    2016-06-01

    Intracranial dural arteriovenous fistula (dAVF) usually results in various problems in the brain. But it can be presented as a myelopathy, which may make early diagnosis and management to be difficult. We recently experienced a case of cervical myelopathy caused by intracranial dAVF. A 60-year-old man presented with a 3-year history of gait disturbance due to a progressive weakness of both legs. Neurological examination revealed spastic paraparesis (grade IV) and Babinski sign on both sides. Magnetic resonance imaging showed serpentine vascular signal voids at C2-T1 on T2-weighted image with increased signal intensity and swelling of spinal cord at C1-C4. We performed a brain computed tomography angiography and found intracranial dAVF with multiple arteriovenous shunts. Venous drainages were noted at tentorial veins and cervical perimedullary veins. After Onyx embolization, the patient showed gradual improvement in motor power and gait disturbance. The venous drainage pattern is a well-known prognostic factor of dAVF. In our case, the intracranial dAVF drained to spinal perimedullary vein, which seemed to result in the ischemic myelopathy. Although it is rare condition, it sometimes can cause serious complications. Therefore, we should keep in mind the possibility of intracranial dAVF when a patient presents myelopathy. PMID:27437016

  18. Microwave Observations on Saturn's Main Rings

    NASA Astrophysics Data System (ADS)

    Zhang, Zhimeng; Hayes, Alexander; Janssen, Michael A.; Nicholson, Philip D.; Cuzzi, Jeffrey N.; de Pater, Imke; Dunn, David; Hedman, Matthew M.; Estrada, Paul R.

    2016-10-01

    Despite considerable study, Saturn's rings continue to challenge current theories for their provenance. Water ice comprises the bulk of Saturn's rings, yet it is the small fraction of non-icy material that is arguably more valuable in revealing clues about the system's origin and age. Herein, we present new measurements of the non-icy material fraction in Saturn's main rings, determined from microwave observations obtained by Cassini Radar and EVLA.Our Cassini Radar observations in the C Ring show an exceptionally high brightness at near-zero azimuthal angles, suggesting a high porosity of 70%-75% for the particles. Furthermore, most regions in the C ring contain about 1-2% silicates while with an enhanced abundance concentrated in the middle C ring reaching a maximum of 6%-11%. We proposed that the C ring has been continuously polluted by meteoroid bombardment for 15-90Myr, while the middle C ring was further contaminated by an incoming Centaur disrupted by Saturn tidal force. Owing to the B ring's high opacity, the particles there are likely to have 85% - 90% porosity, with corresponding non-icy material fractions of ~ 0.3% - 0.5% in the inner and outer B ring, and ~0.1% - 0.2% in the middle regions. For the A ring interior to the Encke gap, the derived non-icy material is ~0.2% - 0.3% everywhere for porosities ranging from 55% - 90%. Finally, our results for the Cassini Division indicate a non-icy material fraction of ~1% - 2% similar to most regions in the C ring, except that the Cassini Division particles are more likely to contain ~ 90% porosity due to the high opacity there. Our results here further support the idea that Saturn's rings may be less than 150 Myr old suggesting an origin scenario in which the rings are derived from the relatively recent breakup of an icy moon.Furthermore, we calibrated and analyzed multi-wavelengths EVLA observation at wavelengths ranging from 0.7cm to 13cm. As the array operates in a wavelength regime where the absorption

  19. The Cadaveric Perfusion and Angiography as a Teaching Tool: Imaging the Intracranial Vasculature in Cadavers

    PubMed Central

    Turkoglu, Erhan; Seckin, Hakan; Gurer, Bora; Ahmed, Azam; Uluc, Kutluay; Pulfer, Kari; Arat, Anıl; Niemann, David; Baskaya, Mustafa K.

    2014-01-01

    Background and Study Aim To enhance the visualization of the intracranial vasculature of cadavers under gross examination with a combination of imaging modalities. Material and Methods A total of 20 cadaver heads were used to test two different perfusion techniques. First, fixed cadaver heads were perfused with water; second, fresh cadavers were perfused with saline and 10% formalin. Subsequently, brains were removed and fixed. The compounds used were silicone rubber, silicone rubber mixed with powdered barium sulfate, and silicone rubber mixed with tantalum dioxide prepared by the first perfusion technique and gelatin mixed with liquid barium prepared with the second technique. Conventional X-ray imaging, computed tomography (CT), dynamic computed tomography (dCT), and postprocessing three-dimensional (3D) images were used to evaluate all the heads. Results Gelatinized barium was better visualized when compared with tantalum dioxide in conventional X-ray images. The blood vessels injected with either tantalum dioxide or gelatinized barium demonstrated a higher enhancement than the surrounding soft tissues with CT or dCT. The quality of the 3D reconstruction of the intracranial vasculature was significantly better in the CT images obtained from the gelatinized barium group. Conclusions Radiologic examinations of the heads injected with gelatinized barium facilitates the 3D understanding of cerebrovascular anatomy as an important tool for neuroanatomy training. PMID:25452903

  20. Primary diffuse leptomeningeal gliomatosis: unusual MRI with non-enhancing nodular lesions on the cerebellar surface and spinal leptomeningeal enhancement

    PubMed Central

    Kastenbauer, S; Danek, A; Klein, W; Yousry, T; Bise, K; Reifenberger, G; Pfister, H

    2000-01-01

    A 28 year old man presented with a 1 month history of symptoms of intracranial hypertension. Examination showed bilateral papilloedema and meningeal signs. Magnetic resonance imaging showed nodular lesions on the cerebellar and pontine surface and thickening of the thoracic spinal leptomeninges. Throughout the course of the disease, contrast enhancement was detected in the spinal leptomeninges but not intracranially. Primary diffuse leptomeningeal gliomatosis (PDLG) was diagnosed by biopsy and later confirmed on necropsy. The present case is remarkable for the nodular superficial cerebellar lesions and the absence of intracranial contrast enhancement of the leptomeninges.

 PMID:10945815

  1. The unruptured intracranial aneurysm treatment score

    PubMed Central

    Brown, Robert D.; Beseoglu, Kerim; Juvela, Seppo; Raymond, Jean; Morita, Akio; Torner, James C.; Derdeyn, Colin P.; Raabe, Andreas; Mocco, J.; Korja, Miikka; Abdulazim, Amr; Amin-Hanjani, Sepideh; Al-Shahi Salman, Rustam; Barrow, Daniel L.; Bederson, Joshua; Bonafe, Alain; Dumont, Aaron S.; Fiorella, David J.; Gruber, Andreas; Hankey, Graeme J.; Hasan, David M.; Hoh, Brian L.; Jabbour, Pascal; Kasuya, Hidetoshi; Kelly, Michael E.; Kirkpatrick, Peter J.; Knuckey, Neville; Koivisto, Timo; Krings, Timo; Lawton, Michael T.; Marotta, Thomas R.; Mayer, Stephan A.; Mee, Edward; Pereira, Vitor Mendes; Molyneux, Andrew; Morgan, Michael K.; Mori, Kentaro; Murayama, Yuichi; Nagahiro, Shinji; Nakayama, Naoki; Niemelä, Mika; Ogilvy, Christopher S.; Pierot, Laurent; Rabinstein, Alejandro A.; Roos, Yvo B.W.E.M.; Rinne, Jaakko; Rosenwasser, Robert H.; Ronkainen, Antti; Schaller, Karl; Seifert, Volker; Solomon, Robert A.; Spears, Julian; Steiger, Hans-Jakob; Vergouwen, Mervyn D.I.; Wanke, Isabel; Wermer, Marieke J.H.; Wong, George K.C.; Wong, John H.; Zipfel, Gregory J.; Connolly, E. Sander; Steinmetz, Helmuth; Lanzino, Giuseppe; Pasqualin, Alberto; Rüfenacht, Daniel; Vajkoczy, Peter; McDougall, Cameron; Hänggi, Daniel; LeRoux, Peter; Rinkel, Gabriel J.E.; Macdonald, R. Loch

    2015-01-01

    Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1–4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1–4.4) for panel members and 4.5 (95% CI 4.3–4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1–4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9–4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019–0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA. PMID:26276380

  2. Intracranial nonvestibular neurinomas: Young neurosurgeons’ experience

    PubMed Central

    Chowdhury, Forhad Hossain; Haque, Mohammod R.; Kawsar, Khandkar A.; Sarker, Mainul H.; Hasan, Mahmudul; Goel, Atul H.

    2014-01-01

    Background and Objectives: Neurinoma arising from other than nonvestibular cranial nerves is less prevalent. Here we present our experiences regarding the clinical profile, investigations, microneurosurgical management, and the outcome of nonvestibular cranial nerve neurinomas. Materials and Methods: From January 2005 to December 2011, the recorded documents of operated nonvestibular intracranial neurinomas were retrospectively studied for clinical profile, investigations, microneurosurgical management, complications, follow-up, and outcomes. Results: The average follow-up was 24.5 months. Total number of cases was 30, with age ranging from 9 to 60 years. Sixteen cases were males and 14 were females. Nonvestibular cranial nerve schwannomas most commonly originated from trigeminal nerve followed by glossopharyngeal+/vagus nerve. There were three abducent nerve schwannomas that are very rare. There was no trochlear nerve schwannoma. Two glossopharyngeal+/vagus nerve schwannomas extended into the neck through jugular foramen and one extended into the upper cervical spinal canal. Involved nerve dysfunction was a common clinical feature except in trigeminal neurinomas where facial pain was a common feature. Aiming for no new neurodeficit, total resection of the tumor was done in 24 cases, and near-total resection or gross total resection or subtotal resection was done in 6 cases. Preoperative symptoms improved or disappeared in 25 cases. New persistent deficit occurred in 3 cases. Two patients died postoperatively. There was no recurrence of tumor till the last follow-up. Conclusion: Nonvestibular schwannomas are far less common, but curable benign lesions. Surgical approach to the skull base and craniovertebral junction is a often complex and lengthy procedure associated with chances of significant morbidity. But early diagnosis, proper investigations, and evaluation, along with appropriate decision making and surgical planning with microsurgical techniques are the

  3. Endovascular treatment of infectious intracranial aneurysms.

    PubMed

    Gross, Bradley A; Puri, Ajit S

    2013-01-01

    Infectious intracranial aneurysms (IIA) are rare but a considerable source of morbidity and mortality as a result of rupture. Most patients with these lesions have considerable medical comorbidities, making endovascular approaches a crucial modality in their treatment armamentarium. Contributing our own case, we performed a comprehensive review of the literature to illustrate overall results and outcomes for patients with IIA treated with endovascular approaches. Incorporating our own case, we found 65 patients harboring 72 IIA across 31 reports. Fifty-one were treated via parent artery occlusion (71%), 17 via direct aneurysm embolization (24%), two via stent-coiling (3%), and two with stent monotherapy (3%). Twenty-nine IIAs were treated with n-butylcyanoacrylate (NBCA) (40%), 25 with coils (35%), seven with Onyx or ethylene vinyl alcohol (10%), five with detachable balloons (7%), four with stents (6%), and one with autologous clot (1%). One case of incomplete aneurysm occlusion and two cases of recanalization were reported. Six symptomatic periprocedural ischemic events were reported (9%), with only three resulting in permanent sequelae (5%). No infectious complications were reported. Incorporating the natural history of the disease, 28 patients were neurologically intact (43%), while seven had died at the time of follow-up (11%). Endovascular treatment of ruptured, symptomatic, or enlarging IIA is an excellent treatment modality with high occlusion rates and low procedure-related complication rates. Distal IIA are more often treated with parent artery occlusion, in our hands, preferentially with Onyx, while proximal lesions may be treated with direct stent-coiling or even flow-diverting stent monotherapy.

  4. 110 GHz hybrid mode-locked fiber laser with enhanced extinction ratio based on nonlinear silicon-on-insulator micro-ring-resonator (SOI MRR)

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Hsu, Yung; Chow, Chi-Wai; Yang, Ling-Gang; Yeh, Chien-Hung; Lai, Yin-Chieh; Tsang, Hon-Ki

    2016-03-01

    We propose and experimentally demonstrate a new 110 GHz high-repetition-rate hybrid mode-locked fiber laser using a silicon-on-insulator microring-resonator (SOI MRR) acting as the optical nonlinear element and optical comb filter simultaneously. By incorporating a phase modulator (PM) that is electrically driven at a fraction of the harmonic frequency, an enhanced extinction ratio (ER) of the optical pulses can be produced. The ER of the optical pulse train increases from 3 dB to 10 dB. As the PM is only electrically driven by the signal at a fraction of the harmonic frequency, in this case 22 GHz (110 GHz/5 GHz), a low bandwidth PM and driving circuit can be used. The mode-locked pulse width and the 3 dB spectral bandwidth of the proposed mode-locked fiber laser are measured, showing that the optical pulses are nearly transform limited. Moreover, stability evaluation for an hour is performed, showing that the proposed laser can achieve stable mode-locking without the need for optical feedback or any other stabilization mechanism.

  5. Ring Around a Galaxy

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Space Telescope Science Institute astronomers are giving the public chances to decide where to aim NASA's Hubble Space Telescope. Guided by 8,000 Internet voters, Hubble has already been used to take a close-up, multi-color picture of the most popular object from a list of candidates, the extraordinary 'polar-ring' galaxy NGC 4650A. Located about 130 million light-years away, NGC 4650A is one of only 100 known polar-ring galaxies. Their unusual disk-ring structure is not yet understood fully. One possibility is that polar rings are the remnants of colossal collisions between two galaxies sometime in the distant past, probably at least 1 billion years ago. What is left of one galaxy has become the rotating inner disk of old red stars in the center. Meanwhile, another smaller galaxy which ventured too close was probably severely damaged or destroyed. The bright bluish clumps, which are especially prominent in the outer parts of the ring, are regions containing luminous young stars, examples of stellar rebirth from the remnants of an ancient galactic disaster. The polar ring appears to be highly distorted. No regular spiral pattern stands out in the main part of the ring, and the presence of young stars below the main ring on one side and above on the other shows that the ring is warped and does not lie in one plane. Determining the typical ages of the stars in the polar ring is an initial goal of our Polar Ring Science Team that can provide a clue to the evolution of this unusual galaxy. The HST exposures were acquired by the Hubble Heritage Team, consisting of Keith Noll, Howard Bond, Carol Christian, Jayanne English, Lisa Frattare, Forrest Hamilton, Anne Kinney and Zolt Levay, and guest collaborators Jay Gallagher (University of Wisconsin-Madison), Lynn Matthews (National Radio Astronomy Observatory-Charlottesville), and Linda Sparke (University of Wisconsin-Madison).

  6. In Vivo Imaging of Twist Drill Drainage for Subdural Hematoma: A Clinical Feasibility Study on Electrical Impedance Tomography for Measuring Intracranial Bleeding in Humans

    PubMed Central

    Xu, Canhua; Yang, Bin; Li, Jianbo; Fu, Feng; Fei, Zhou; Dong, Xiuzhen

    2013-01-01

    Intracranial bleeding is one of the most severe medical emergencies in neurosurgery. Early detection or diagnosis would largely reduce the rate of disability and mortality, and improve the prognosis of the patients. Electrical Impedance Tomography (EIT) can non-invasively image the internal resistivity distribution within a human body using a ring of external electrodes, and is thus a promising technique to promptly detect the occurrence of intracranial bleedings because blood differs from other brain tissues in resistivity. However, so far there is no experimental study that has determined whether the intracranial resistivity changes in humans could be repeatedly detected and imaged by EIT. Hence, we for the first time attempt to clinically validate this by in vivo imaging the influx and efflux of irrigating fluid (5% dextrose in water, D5W) during the twist-drill drainage operation for the patients with subdural hematoma (SDH). In this study, six patients (four male, two female) with subacute or chronic SDH received the surgical operation in order to evacuate the hematoma around subdural region, and EIT measurements were performed simultaneously on each patient’s head. The results showed that the resistivity significantly increased on the corresponding position of EIT images during the influx of D5W and gradually decreased back to baseline during the efflux. In the quantitative analysis, the average resistivity values demonstrated the similar results and had highly linear correlation (R2 = 0.93±0.06) with the injected D5W volumes, as well as the area of the resistivity gain(R2 = 0.94±0.05). In conclusion, it was clinically validated that intracranial resistivity changes in humans were detectable and quantifiable by the EIT method. After further technical improvements, EIT has the great potential of being a routine neuroimaging tool for early detection of intracranial bleedings. PMID:23372808

  7. An isolated intracranial mucocoele herniated from the frontal sinus.

    PubMed

    Huang, K L; Huang, C C; Lee, T J; Huang, C C

    2015-01-01

    Mucocoeles are chronic mucosa-lined retention cysts that occur due to sinus ostium obstruction and expand along the path of least resistance, most commonly involving the frontal sinus. A frontal mucocoele typically appears as a smooth and rounded expansile enlargement of a completely opacified frontal sinus, with or without thinning of the bony wall of the sinus. Here we report a rare case of isolated intracranial mucocoele that presented with posterior herniation to the anterior cranial fossa through a small bony defect on the posterior table of the frontal sinus. The findings upon imaging could easily be confused with intracranial abscess, potentially leading to craniotomy drainage. In the present case of mucocoele, the frontal intracranial lesion was completely resolved following endoscopic frontal sinusotomy.

  8. Ten self-inflicted intracranial penetrating nail gun injuries

    PubMed Central

    Yuh, Sung-Joo; Alaqeel, Ahmed

    2015-01-01

    Penetrating craniocerebral injuries from nail gun use are rare. We describe a case of 10 self-inflicted nail gun injuries with intracranial penetrations. We also review the literature and discuss management strategies of such craniocerebral trauma. A 33-year-old male with a long-standing history of severe depression took a nail gun and sustained 10 penetrating intracranial injuries. Initial neuroimaging revealed 10 penetrating nails, all sparing the major cerebral vasculature. Immediate surgical removal was undertaken in the surgical suite using a combination of craniotomies, craniectomies, and blind removal. Intracranial injuries from self-inflicted nail gun misuse is becoming increasingly more frequent. Initial appropriate clinical decision-making are critical in preventing further cortical or vascular damage. PMID:26166596

  9. Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.

    1998-01-01

    Prevention of secondary brain injuries following head can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop (PPLL) devise, which was developed and patented, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year one studies involved instrument improvements and measurement of altered intracranial distance with altered ICP in fresh cadavera. Our software was improved to facilitate future studies of normal subjects and trauma patients. Our bench studies proved that PPLL output correlated highly with changes in path length across a model cranium. Cadaveric studies demonstrated excellent compact, noninvasive devise for monitoring changes in intracranial distance may aid in the early detection of elevated ICP, decreasing risk of secondary brain injury and infection, and returning head-injured patients to duty.

  10. Primary varicella infection presenting with headache and elevated intracranial pressure.

    PubMed

    Gilad, Oded; Shefer-Averbuch, Noa; Garty, Ben Zion

    2015-05-01

    Primary varicella infection may be associated with neurologic complications, such as cerebritis and meningoencephalitis. Several cases of varicella infection with elevated intracranial pressure have been reported. We describe a 13-year-old immunocompetent girl who presented with a clinical picture of headaches and elevated intracranial pressure as the only manifestation of primary varicella zoster infection. The working diagnosis at first was pseudotumor cerebri based on complaints of headache of 2 weeks' duration, in addition to vomiting and papilledema, without fever or skin eruption. On lumbar puncture, opening pressure was 420 mmH2O, but mild pleocytosis and mildly elevated protein level ruled out the diagnosis of pseudotumor cerebri. Our patient had no history of previous varicella infection, and she did not receive the varicella zoster vaccine. Serology tests, done on admission and repeated 2 months later, suggested primary varicella infection. The literature on varicella infection associated with pseudotumor cerebri or elevated intracranial pressure is reviewed.

  11. Intracranial granulocytic sarcoma: two cases and literature review

    PubMed Central

    Wang, Huanyu; Wang, Hong; Ma, Quanfeng; Chen, Yiyang

    2015-01-01

    Intracranial granulocytic sarcoma was a relatively rare tumor composed of myeloid blasts and/or immature myeloid cells in an extramedullary site which is associated with acute/chronic myeloid leukemia. In this paper, two cases of intracranial granulocytic sarcoma, one male aged 36 and one 28-year-old female, were reported to improve the diagnosis and treatment of such diseases. Diagnostic and treatment procedures for them were retrospectively summarized and relevant literature reviews were combined. Pathological biopsy was conducted to validate the diagnosis. Surgical resections in combination with chemotherapy were performed. The differential diagnosis of intracranial granulocytic sarcoma from malignant lymphomas and alternative small round cell malignancy was confirmed by biopsy and immunohistochemistry. PMID:26770615

  12. Intracranial hemorrhage revealing pseudohypoparathyroidism as a cause of fahr syndrome.

    PubMed

    Swami, Abhijit; Kar, Giridhari

    2011-01-01

    Pseudohypoparathyroidism is an infrequently encountered disease. It is one of the causes of Fahr syndrome which also is a rare clinical entity caused by multiple diseases. A 4-year-old man hospitalized for sudden onset left hemiparesis and hypertension was diagnosed to have right thalamic and midbrain hemorrhage on plain CT scan of the head which also revealed co-existent extensive intracranial calcifications involving the basal ganglia and cerebellum bilaterally. General physical examination revealed features of Albright hereditary osteodystrophy, goitre, hypertension, left hemiparesis, and signs of cerebellar dysfunction. Laboratory findings suggested hypocalcemia, hyperphosphatemia along with high TSH, low FT(4), low FT(3), and high anti-TPO antibody. Though bilateral intracranial calcifications are usually encountered as an incidental radiological finding in the CT scan of brain, in this case, the patient admitted for thalamic and midbrain hemorrhage was on investigation for associated intracranial calcification, and goitre was also found to have coexisting pseudohypoparathyroidism and autoimmune hypothyroidism.

  13. Smoke Ring Physics

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2011-01-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  14. Lower esophageal ring (Schatzki)

    MedlinePlus

    ... narrowed area to stretch the ring. Sometimes, a balloon is placed in the area and inflated, to help widen the ring. Outlook (Prognosis) Swallowing problems may return. You may need repeat treatment. When to Contact a Medical Professional Call your health care provider if you ...

  15. EBT ring physics

    SciTech Connect

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)

  16. Contactless Magnetic Slip Ring

    NASA Technical Reports Server (NTRS)

    Kumagai, Hiroyuki (Inventor); Deardon, Joe D. (Inventor)

    1997-01-01

    A contactless magnetic slip ring is disclosed having a primary coil and a secondary coil. The primary and secondary coils are preferably magnetically coupled together, in a highly reliable efficient manner, by a magnetic layered core. One of the secondary and primary coils is rotatable and the contactless magnetic slip ring provides a substantially constant output.

  17. Smoke Ring Physics

    NASA Astrophysics Data System (ADS)

    Huggins, Elisha

    2011-11-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampère's law in an introductory physics course. We discuss these common features.

  18. Factors Influencing the Management of Unruptured Intracranial Aneurysms.

    PubMed

    Gillani, Rebecca L; Podraza, Katherine M; Luthra, Nijee; Origitano, Thomas C; Schneck, Michael J

    2016-01-01

    Background Deciding how to manage an unruptured intracranial aneurysm can be difficult for patients and physicians due to controversies about management. The decision as to when and how to intervene may be variable depending on physicians' interpretation of available data regarding natural history and morbidity and mortality of interventions. Another significant factor in the decision process is the patients' conception of the risks of rupture and interventions and the psychological burden of harboring an unruptured intracranial aneurysm. Objective  To describe which factors are being considered when patients and their physicians decide how to manage unruptured intracranial aneurysms.  Materials & methods  In a retrospective chart review study, we identified patients seen for evaluation of an unruptured intracranial aneurysm. Data was collected regarding patient and aneurysm characteristics. The physician note pertaining to the management decision was reviewed for documented reasons for intervention. Results  Of 88 patients included, 36 (41%) decided to undergo open or endovascular surgery for at least one unruptured intracranial aneurysm. Multiple aneurysms were present in 14 (16%) patients. Younger patients and current smokers were more likely to undergo surgery, but gender and race did not affect management. Aneurysm size and location strongly influenced management. The most common documented reasons underlying the decision of whether to intervene were the risk of rupture, aneurysm size, and risks of the procedure. For 23 aneurysms (21%), there were no factors documented for the management decision.  Conclusion  The risk of rupture of unruptured intracranial aneurysms may be underestimated by currently available natural history data. Major factors weighed by physicians in management decisions include aneurysm size and location, the patient's age, and medical comorbidities along with the risk of procedural complications. Additional data is needed to define

  19. Jupiter's Gossamer Rings Explained.

    NASA Astrophysics Data System (ADS)

    Hamilton, D. P.

    2003-05-01

    Over the past several years, Galileo measurements and groundbased imaging have drastically improved our knowledge of Jupiter's faint ring system. We now recognize that the ring consists of four components: a main ring 7000km wide, whose inner edge blossoms into a vertically-extended halo, and a pair of more tenuous Gossamer rings, one associated with each of the small moons Thebe and Amalthea. When viewed edge on, the Gossamer rings appear as diaphanous disks whose thicknesses agree with the vertical excursions of the inclined satellites from the equatorial plane. In addition, the brightness of each Gossamer ring drops off sharply outside the satellite orbits. These correlations allowed Burns etal (1999, Science, 284, 1146) to argue convincingly that the satellites act as sources of the dusty ring material. In addition, since most material is seen inside the orbits of the source satellites, an inwardly-acting dissipative force such as Poynting-Robertson drag is implicated. The most serious problem with this simple and elegant picture is that it is unable to explain the existence of a faint swath of material that extends half a jovian radius outward from Thebe. A key constraint is that this material has the same thickness as the rest of the Thebe ring. In this work, we identify the mechanism responsible for the outward extension: it is a shadow resonance, first investigated by Horanyi and Burns (1991, JGR, 96, 19283). When a dust grain enters Jupiter's shadow, photoelectric processes shut down and the grain's electric charge becomes more negative. The electromagnetic forces associated with the varying charge cause periodic oscillations in the orbital eccentricity and semimajor axis as the orbital pericenter precesses. This results in a ring which spreads both inward and outward of its source satellite while preserving its vertical thickness - just as is observed for the Thebe ring. Predictions of the model are: i) gaps of micron-sized material interior to Thebe and

  20. Jupiter's Rings: Sharpest View

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons spacecraft took the best images of Jupiter's charcoal-black rings as it approached and then looked back at Jupiter. The top image was taken on approach, showing three well-defined lanes of gravel- to boulder-sized material composing the bulk of the rings, as well as lesser amounts of material between the rings. New Horizons snapped the lower image after it had passed Jupiter on February 28, 2007, and looked back in a direction toward the sun. The image is sharply focused, though it appears fuzzy due to the cloud of dust-sized particles enveloping the rings. The dust is brightly illuminated in the same way the dust on a dirty windshield lights up when you drive toward a 'low' sun. The narrow rings are confined in their orbits by small 'shepherding' moons.

  1. Impact of Nursing Educational Program on Reducing or Preventing Postoperative Complications for Patients after Intracranial Surgery

    ERIC Educational Resources Information Center

    Elmowla, Rasha Ali Ahmed Abd; El-Lateef, Zienab Abd; El-khayat, Roshdy

    2015-01-01

    Intracranial surgery means any surgery performed inside the skull to treat problems in the brain and surrounding structures. Aim: Evaluate the impact of nursing educational program on reducing or preventing postoperative complications for patients after intracranial surgery. Subjects and methods: Sixty adult patients had intracranial surgery (burr…

  2. Unusual Radiologic Finding of Intracranial Inflammatory Myofibroblastic Tumor Presenting a Cyst with Mural Nodule.

    PubMed

    Park, Jong-Heok; Yoon, Wan-Soo; Chung, Dong-Sup

    2015-10-01

    An intracranial cyst tumor with a mural nodule can be representative of some types of brain tumors, but is a rare presentation of intracranial inflammatory myofibroblastic tumor (IMT). Herein, we report the case of an intracranial IMT in a 48-year-old woman presenting with the extremely unusual radiologic findings of a cyst with a mural nodule.

  3. Postoperative evaluation for intracranial recurrence of medulloblastoma: MR findings with Gadopentetate dimeglumine

    SciTech Connect

    Meyers, S.P.; Wildenhain, S.; Chess, M.A.; Tarr, W.A.

    1994-09-01

    Purpose: To characterize the gadopentetate dimeglumine-enhanced MR features of recurrent medulloblastoma. Methods: The postsurgical gadopentetate dimeglumine-enhanced MR images of 48 patients (206 head examinations) with prior resection of medulloblastoma were retrospectively evaluated for enhancement in the brain parenchyma, meninges (dura, pia-arachnoid), and ventricles. Results: Nineteen patients had recurrent tumor as determined by clinical course and positive imaging studies. Seventeen patients with recurrent disease had intracranial enhancement predominating in the pia-arachnoid (63%) or as a focal nodular brain lesion (26%). Three of these patients also had intraventricular metastases. None of the clinically healthy patients had these findings. One patient with recurrent disease had extensive skeletal metastases without involvement of the central nervous system. Dural enhancement was observed in patients both with (42%) and without (38%) recurrent tumor. Conclusion: The MR findings of pia-arachnoidal or focal nodular brain enhancement are highly specific in the diagnosis of recurrent medulloblastoma. Pia-arachnodal or focal nodular brain enhancement were also a reliable indicator of recurrent medulloblastoma. Not all intraventricular metastases enhance with gadopentetate dimeglumine, and careful evaluation for nonenhancing lesions within the ventricles should be made on postoperative MR examines. 27 refs., 11 figs., 1 tab.

  4. Harmonics tracking of intracranial and arterial blood pressure waves.

    PubMed

    Shahsavari, Sima; McKelvey, Tomas

    2008-01-01

    Considering cardiorespiratory interaction and heart rate variability, a new approach is proposed to decompose intracranial pressure and arterial blood pressure to their different harmonics. The method is based on tracking the amplitudes of the harmonics by a Kalman filter based tracking algorithm. The algorithm takes benefit of combined frequency estimation technique which uses both Fast Fourier Transform and RR-interval detection. The result would be of use in intracranial pressure and arterial blood pressure waveform analysis as well as other investigations which need to estimate contribution of specific harmonic in above mentioned signals such as Pressure-Volume Compensatory Reserve assessment.

  5. Fast virtual stenting with deformable meshes: application to intracranial aneurysms.

    PubMed

    Larrabide, Ignacio; Radaelli, Alessandro; Frangi, Alejandro

    2008-01-01

    Intracranial stents are medical devices that are becoming increasingly popular in the treatment of intracranial aneurysms. A methodology that predicts the released stent configuration prior to intervention has the potential to support the physician in the selection of the optimal approach for a specific patient. This paper proposes a fast virtual stenting technique based on constrained simplex deformable models that is able to virtually release stents in arbitrarily shaped vessel and aneurysm models. The technique effectively embeds the geometrical properties of the stent (cell design, strut size and shape and angles between struts) and achieves favorable execution times of the order of one minute.

  6. Intracranial meningioma with ophthalmoplegia in a rhesus macaque (Macaca mulatta).

    PubMed

    Tanaka, Takayuki; Canfield, Don R

    2012-10-01

    A 21-y-old female rhesus macaque presented with signs of internal and external ophthamoplegia, including anisocoria and ptosis. Ophthalmoplegia is the paralysis or weakness of one or more intraocular or extraocular muscles that control the movement of eye; this condition can be caused by neurologic or muscle disorders. The macaque was euthanized due to progression of clinical symptoms, and postmortem gross examination revealed a mass at the base of the brain attached to the meninges. Histopathologic examination led to the diagnosis of intracranial meningioma. Here we describe a case of intracranial meningioma with internal and external ophthalmoplegia in a rhesus macaque (Macaca mulatta).

  7. Intracranial hypotension secondary to spinal pathology: Diagnosis and treatment.

    PubMed

    Sartip, Kamyar; McKenna, Gregory; Spina, Michael; Grahovac, Stephen

    2016-04-01

    Spinal pathology resulting in cerebrospinal fluid (CSF) leak and intracranial hypotension is an infrequently reported and a potentially severe cause of headaches. We present a case of cerebrospinal fluid (CSF) leak caused by a thoracic disk herniation successfully treated with two targeted epidural blood patches. Although patients typically present with orthostatic headaches, the imaging findings of intracranial hypotension should prompt investigation of the spine for site and cause of the CSF leakage. Treatment includes autologous blood patch and surgery in refractory cases. PMID:26914140

  8. Sympathetic storming in a patient with intracranial basal ganglia hemorrhage.

    PubMed

    Siu, Gilbert; Marino, Michael; Desai, Anjuli; Nissley, Frederick

    2011-03-01

    Neurologic deficits and medical complications are common sequelae after intracranial hemorrhage. Among the medical complications, sympathetic storming is relatively rare. We describe a case of a patient with an acute right basal ganglia hemorrhage. During the patient's hospital course, he developed tachypnea, diaphoresis, hypertension, hyperthermia, and tachycardia for three consecutive days. A complete laboratory work-up and imaging studies were unremarkable for infectious etiology, new intracranial hemorrhage, and deep vein thrombosis. The patient was diagnosed with sympathetic storming, a relatively uncommon cause of these symptoms. The storming was secondary to a kinked Foley catheter, and subsequent placement of a new catheter resulted in the resolution of his symptoms. PMID:21297401

  9. Hypertonic saline in elevated intracranial pressure: past, present, and future.

    PubMed

    Surani, Salim; Lockwood, Geoff; Macias, Melissa Y; Guntupalli, Bharat; Varon, Joseph

    2015-01-01

    Hypertonic Saline (HS) has been a proven and effective therapy and a safe alternative to mannitol in patients with increase intracranial pressure (ICP). We hereby present a case of 25-year-old women with intracranial bleed secondary to right parietal arteriovenous malformation. Patient underwent surgery for evacuation of hematoma and resection of arteriovenous malformation. Post- operative course was complicated by recurrent episodes of elevated ICP. She received total of 17 doses of 23.4% HS and 30 doses of mannitol with good outcome. Despite reluctance from some clinicians to use HS, hypertonic saline seems to be a safe and effective therapy.

  10. Intra-cranial Toxoplasmosis in an Immunocompetent Female.

    PubMed

    Hoti, Yaser Ud Din; Aziz, Amir; Ishaque, Khurram; Abbas, Sadia; Ud Din, Tariq Salah

    2016-06-01

    Intra-cranial toxoplasmosis is a rare entity occurring mostly in immunosuppressed individuals. It is extremely rare in an immune competent patient. Toxoplasmosis is the third leading cause of food borne illness. Depending upon the site, degree of inflammation and local damage, toxoplasmosis encephalitis and cranial abscess can cause long lasting neurologic sequel. With modern imaging techniques, toxoplasmosis antibody titers, slit lamp examination and brain biopsy, there is improvement in diagnosis along with reduction in the mortality rate. We present a case illustrating the radiological manifestations, complications, potential pitfalls in diagnosis and treatment of intra-cranial toxoplasmosis in immunocompetent patient. PMID:27376217

  11. Changes in intracranial pressure associated with delayed cerebral radionecrosis

    SciTech Connect

    Brock, M.; Cervos-Navarro, J.; Holdorff, B.

    1984-07-01

    Continuous recording of intracranial pressure (ICP) from one lateral ventricle in a case of histologically proven delayed temporal radionecrosis due to previous irradiation of the pituitary gland for the treatment of an adiposity of the Cushing type has revealed the occurrence of B-waves and ramplike waves despite the absence of raised intracranial pressure. Ventriculo-atrial shunting failed to relieve the severe psychic symptomatology, which was due to direct tissue damage. These observations indicate that B-waves may have a neurogenic origin.

  12. STEEL TRUSS TENSION RING SUPPORTING DOME ROOF. TENSION RING COVERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STEEL TRUSS TENSION RING SUPPORTING DOME ROOF. TENSION RING COVERED BY ARCHITECTURAL FINISH. TENSION RING ROLLER SUPPORT AT COLUMN OBSCURED BY COLUMN COVERINGS. - Houston Astrodome, 8400 Kirby Drive, Houston, Harris County, TX

  13. Mechanical seal having a double-tier mating ring

    DOEpatents

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  14. Nanofiber-segment ring resonator

    NASA Astrophysics Data System (ADS)

    Jones, D. E.; Hickman, G. T.; Franson, J. D.; Pittman, T. B.

    2016-08-01

    We describe a fiber ring resonator comprised of a relatively long loop of standard single-mode fiber with a short nanofiber segment. The evanescent mode of the nanofiber segment allows the cavity-enhanced field to interact with atoms in close proximity to the nanofiber surface. We report on an experiment using a warm atomic vapor and low-finesse cavity, and briefly discuss the potential for reaching the strong coupling regime of cavity QED by using trapped atoms and a high-finesse cavity of this kind.

  15. Pediatric intracranial gunshot wounds: the Memphis experience.

    PubMed

    DeCuypere, Michael; Muhlbauer, Michael S; Boop, Frederick A; Klimo, Paul

    2016-05-01

    OBJECTIVE Penetrating brain injury in civilians is much less common than blunt brain injury but is more severe overall. Gunshot wounds (GSWs) cause high morbidity and mortality related to penetrating brain injury; however, there are few reports on the management and outcome of intracranial GSWs in children. The goals of this study were to identify clinical and radiological factors predictive for death in children and to externally validate a recently proposed pediatric prognostic scale. METHODS The authors conducted a retrospective review of penetrating, isolated GSWs sustained in children whose ages ranged from birth to 18 years and who were treated at 2 major metropolitan Level 1 trauma centers from 1996 through 2013. Several standard clinical, laboratory, and radiological factors were analyzed for their ability to predict death in these patients. The authors then applied the St. Louis Scale for Pediatric Gunshot Wounds to the Head, a scoring algorithm that was designed to provide rapid prognostic information for emergency management decisions. The scale's sensitivity, specificity, and positive and negative predictability were determined, with death as the primary outcome. RESULTS Seventy-one children (57 male, 14 female) had a mean age of 14 years (range 19 months to 18 years). Overall mortality among these children was 47.9%, with 81% of survivors attaining a favorable clinical outcome (Glasgow Outcome Scale score ≥ 4). A number of predictors of mortality were identified (all p < 0.05): 1) bilateral fixed pupils; 2) deep nuclear injury; 3) transventricular projectile trajectory; 4) bihemispheric injury; 5) injury to ≥ 3 lobes; 6) systolic blood pressure < 100 mm Hg; 7) anemia (hematocrit < 30%); 8) Glasgow Coma Scale score ≤ 5; and 9) a blood base deficit < -5 mEq/L. Patient age, when converted to a categorical variable (0-9 or 10-18 years), was not predictive. Based on data from the 71 patients in this study, the positive predictive value of the St

  16. The Enceladus Ring

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] The Enceladus Ring (labeled)

    This excellent view of the faint E ring -- a ring feature now known to be created by Enceladus -- also shows two of Saturn's small moons that orbit within the ring, among a field of stars in the background.

    The E ring extends from three to eight Saturn radii -- about 180,000 kilometers (118,000 miles) to 482,000 kilometers (300,000 miles). Its full extent is not visible in this view.

    Calypso (22 kilometers, or 14 miles across) and Helene (32 kilometers, or 20 miles across) orbit within the E ring's expanse. Helene skirts the outer parts of the E ring, but here it is projected in front of a region deeper within the ring.

    Calypso and Helene are trojan satellites, or moons that orbit 60 degrees in front or behind a larger moon. Calypso is a Tethys trojan and Helene is a trojan of Dione.

    An interesting feature of note in this image is the double-banded appearance of the E-ring, which is created because the ring is somewhat fainter in the ringplane than it is 500-1,000 kilometers (300-600 miles) above and below the ringplane. This appearance implies that the particles in this part of the ring have nonzero inclinations (a similar affect is seen in Jupiter's gossamer ring). An object with a nonzero inclination does not orbit exactly at Saturn's ringplane. Instead, its orbit takes it above and below the ringplane. Scientists are not entirely sure why the particles should have such inclinations, but they are fairly certain that the reason involves Enceladus.

    One possible explanation is that all the E ring particles come from the plume of icy material that is shooting due south out of the moon's pole. This means all of the particles are created with a certain velocity out of the ringplane, and then they orbit above and below that plane.

    Another possible explanation is that Enceladus produces particles with a range of speeds, but the moon gravitationally

  17. Severe symptomatic intracranial internal carotid artery stenosis treated with intracranial stenting: a single center study with 58 patients

    PubMed Central

    Wang, Zi-Liang; Gao, Bu-Lang; Li, Tian-Xiao; Cai, Dong-Yang; Zhu, Liang-Fu; Xue, Jiang-Yu; Bai, Wei-Xing; Li, Zhao-Shuo

    2016-01-01

    PURPOSE We aimed to investigate the safety and effectiveness of intracranial stenting in a population with severe (≥70%) symptomatic intracranial internal carotid artery (ICA) atherosclerotic stenosis. METHODS Fifty-eight patients with severe intracranial ICA atherosclerotic stenosis were prospectively enrolled. The baseline data, cerebral angiography, success rate, perioperative complications, clinical and imaging follow-up were prospectively analyzed. RESULTS All patients had successful intracranial stenting (100%), and the mean degree of stenosis was improved from 84.3%±7.5% to 23.5%±5.1% after the stent procedure. During the 30-day perioperative period, only one patient (1.7%) had ischemic stroke. Seven patients (12.1%) had headache and dysphoria. Thirty-six patients (62.1%) had clinical follow-up for 6–68 months after stenting. Five female patients (13.9%) had ipsilateral stroke including one death, but no disabling stroke, while three other patients (8.3%) had ipsilateral temporary ischemic attack (TIA). The recurrent stroke rate was higher in patients presenting with stroke (4/17, 23.5%) than in patients presenting with TIA (1/19, 5.3%), with no statistical significance (P = 0.33). Thirteen patients (22.4%) had imaging follow-up of 5–12 months following stenting, five of whom (38.5%) had in-stent restenosis. CONCLUSION Intracranial stenting for patients with intracranial ICA atherosclerotic stenosis has a low perioperative stroke rate and decent outcome on long-term follow-up, despite a relatively high in-stent restenosis rate. PMID:26809831

  18. Combining bayesian source imaging with equivalent dipole approach to solve the intracranial EEG source localization problem.

    PubMed

    Le Cam, Steven; Caune, Vairis; Ranta, Radu; Korats, Gundars; Louis-Dorr, Valerie

    2015-08-01

    The brain source localization problem has been extensively studied in the past years, yielding a large panel of methodologies, each bringing their own strengths and weaknesses. Combining several of these approaches might help in enhancing their respective performance. Our study is carried out in the particular context of intracranial recordings, with the objective to explain the measurements based on a reduced number of dipolar activities. We take benefit of the sparse nature of the Bayesian approaches to separate the noise from the source space, and to distinguish between several source contributions on the electrodes. This first step provides accurate estimates of the dipole projections, which can be used as an entry to an equivalent current dipole fitting procedure. We demonstrate on simulations that the localization results are significantly enhanced by this post-processing step when up to five dipoles are activated simultaneously.

  19. How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

    PubMed

    Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

    2012-11-01

    The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.

  20. How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

    PubMed

    Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

    2012-11-01

    The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display. PMID:23053367

  1. Earth: A Ringed Planet?

    NASA Astrophysics Data System (ADS)

    Hancock, L. O.; Povenmire, H.

    2010-12-01

    Among the most beautiful findings of the Space Age have been the discoveries of planetary rings. Not only Saturn but also Jupiter, Uranus and Neptune have rings; Saturn’s ring system has structures newly discovered; even Saturn's moon Rhea itself has a ring. All these are apparently supplied by material from the planetary moons (Rhea's ring by Rhea itself). The question naturally arises, why should the Earth not have a ring, and on the other hand, if it does, why has it not been observed? No rings have yet been observed in the inner solar system, but after all, rings in the inner solar system might simply tend to be fainter and more transient than those of the outer solar system: the inner solar system is more affected by the solar wind, and the Sun’s perturbing gravitational influence is greater. J.A. O’Keefe first suggested (1980) that Earth might have a ring system of its own. An Earth ring could account for some climate events. O’Keefe remarked that formation or thickening of a ring system in Earth’s equatorial plane could drive glaciation by deepening the chill of the winter hemisphere. (It is very well established that volcanic dust is an effective agent for the extinction of sunlight; this factor can be overwhelmingly apparent in eclipse observations.) O’Keefe died in 2000 and the speculation was not pursued, but the idea of an Earth ring has a prima facie reasonableness that calls for its renewed consideration. The program of this note is to hypothesize that, as O’Keefe proposed: (a) an Earth ring system exists; (b) it affects Earth's weather and climate; (c) the tektite strewn fields comprise filaments of the ring fallen to Earth's surface on various occasions of disturbance by comets or asteroids. On this basis, and drawing on the world's weather records, together with the Twentieth Century Reanalysis by NCEP/CIRES covering the period 1870-2010 and the geology of the tektite strewn fields, we herein propose the hypothesized Earth ring

  2. Hot piston ring tests

    NASA Astrophysics Data System (ADS)

    Allen, David J.; Tomazic, William A.

    1987-12-01

    As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

  3. Dynamics of narrow rings

    NASA Technical Reports Server (NTRS)

    Dermott, S. F.

    1984-01-01

    The ring models described here were developed to account for the dynamical problems posed by the narrow rings of Uranus. Some of these rings are now known to be eccentric, inclined, nonuniform in width, optically thick, and narrow, with very sharp edges. The eccentric rings have common pericenters and large, positive eccentricity gradients. The theory of shepherding satellites successfully accounts for most of these features and can also account for some features of the narrow Saturnian rings, in particular, waves, kinks, and periodic variations in brightness. Outstanding problems include the putative relation between eccentricity and inclination displayed by eight of the nine Uranian rings, and the magnitudes of the tidal torques acting on the shepherding satellites. The horseshoe-orbit model, although viable, probably has more application to the narrow rings from which the Saturnian coorbital satellites formed. The angular momentum flow rate due to particle collisions is a minimum at the Lagrangian equilibrium points L(4) and L(5), and one can expect accretion to be rapid at these points.

  4. Hot piston ring tests

    NASA Technical Reports Server (NTRS)

    Allen, David J.; Tomazic, William A.

    1987-01-01

    As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

  5. Dynamics of the Uranian Rings

    NASA Technical Reports Server (NTRS)

    Dermott, S. F.

    1984-01-01

    Some of the problems of the shepherding satellite model of Goldreich ant tremaine are discussed. The following topics are studied: (1) optical depths of the all the observed narrow rings; (2) satellite and ring separation timescales; (3) ring edge sharpness; (4) shock formation in narrow rings; (5) the existence of small satellites near the Uranian rings; and (6) the apse and node alignments of the eccentric and inclined rings.

  6. Theodolite Ring Lights

    NASA Technical Reports Server (NTRS)

    Clark, David

    2006-01-01

    Theodolite ring lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite ring light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite ring light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.

  7. Alternative parallel ring protocols

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Foudriat, E. C.; Maly, Kurt J.; Kale, V.

    1990-01-01

    Communication protocols are know to influence the utilization and performance of communication network. The effect of two token ring protocols on a gigabit network with multiple ring structure is investigated. In the first protocol, a mode sends at most one message on receiving a token. In the second protocol, a mode sends all the waiting messages when a token is received. The behavior of these protocols is shown to be highly dependent on the number of rings as well as the load in the network.

  8. Intracranial Fusarium Fungal Abscess in an Immunocompetent Patient: Case Report and Review of the Literature

    PubMed Central

    Peterson, Asa; Pham, Martin H.; Lee, Brian; Commins, Deborah; Cadden, Joseph; Giannotta, Steven L.; Zada, Gabriel

    2014-01-01

    Introduction Fusarium spp is an omnipresent fungal species that may lead to fatal infections in immunocompromised populations. Spontaneous intracranial infection by Fusarium spp in immunocompetent individuals is exceedingly rare. Case Report An immunocompetent 33-year-old Hispanic woman presented with persistent headaches and was found to have a contrast-enhancing mass in the left petrous apex and prepontine cistern. She underwent a subsequent craniotomy for biopsy and partial resection that revealed a Fusarium abscess. She had a left transient partial oculomotor palsy following the operation that resolved over the next few weeks. She was treated with long-term intravenous antifungal therapy and remained at her neurologic baseline 18 months following the intervention. Discussion To our knowledge, this is the first reported case of Fusarium spp brain abscess in an immunocompetent patient. Treatment options include surgical intervention and various antifungal medications. Conclusion This case demonstrates the rare potential of intracranial Fusarium infection in the immunocompetent host, as well as its successful treatment with surgical aspiration and antifungal therapy. PMID:25485222

  9. Bilingual aphasia due to spontaneous acute subdural haematoma from a ruptured intracranial infectious aneurysm.

    PubMed

    Vajramani, Girish V; Akrawi, Hawar; McCarthy, Rosaleen A; Gray, William P

    2008-09-01

    We report a case of spontaneous subdural haematoma due to ruptured intracranial infectious aneurysm, presenting with bilingual aphasia and illustrating differential language recovery. A 62-year-old right-handed bilingual gentleman, with a diagnosis of infective endocarditis, developed headache and became expressively aphasic in the English language. Three days later he was receptively and expressively aphasic in both English and Arabic. Cranial MRI scans showed a left-sided acute subdural haematoma with mass effect and midline shift. Contrast CT brain scans showed an enhancing speck adjacent to the clot and cerebral angiogram confirmed a distal middle cerebral artery aneurysm. He underwent image-guided craniotomy, evacuation of the subdural haematoma and excision of the aneurysm. Histopathological examination was consistent with an infectious intracranial aneurysm. Postoperatively his aphasia did not improve immediately. He had widened pulse pressure due to severe aortic regurgitation, confirmed on echocardiography. He underwent aortic valve replacement and mitral valve repair, following which his aphasia recovered gradually. Initially the recovery of his language was limited to Arabic. About a week later he recovered his English language as well. At 3-year follow-up he is doing well and has no neurological deficits. His aphasia has recovered completely. The present case is unique because of (a) presence of pure subdural haematoma, and (b) the differential susceptibility and recovery of native (L1) and acquired language (L2) in presence of a common pathology. The neurology of language in a bilingual is analysed and possible mechanisms discussed.

  10. Surgery of intracranial aneurysms at Yonsei University: 780 cases.

    PubMed

    Lee, K C

    1991-03-01

    Seven hundred and eighty patients with intracranial aneurysm, which were surgically treated by the author since 1976, were analyzed. Strategies important for intracranial aneurysm surgery were the timing of surgery, preoperative preparation and intraoperative management. The best management outcome could be achieved by early operation, removal of subarachnoid blood clot, maintenance of circulating blood volume, administration of nimodipine, and meticulous surgical tactics to avoid pitfalls. Indications for aneurysm surgery in the acute phase were determined by intracerebral hematoma, angiographic findings, clinical grade, general physical status and readiness of the surgical team. Important goals to be considered during the operation were obtaining a slack brain, preparation of proximal control, protection of the brain, awareness of microsurgical anatomy, and complete dissection of the sac. The morbidity and mortality were 2.7% and 4.0%, respectively. The mortality was attributed to intracranial causes in 20 cases (poor grade, delayed ischemic deficits, rebleeding, postoperative infarction, and postoperative epidural hematoma), extracranial causes in 7 cases (pulmonary embolism, heparin induced intracerebral hemorrhage, hepatic failure, myocardial infarction, and gastrointestinal bleeding), and unknown problems in 5 cases. The postoperative intracerebral hemorrhage occurred in 16 cases and seemed to be caused by one or more of the following events: cerebral infarction developed during the preoperative period, occlusion of the cerebral veins during the Sylvian dissection, cerebral retraction and/or sudden change of intracranial hemodynamics. Hydrocephalus, almost always a communicating type as confirmed by isotope cisternography, was managed by lumboperitoneal shunt.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2046205

  11. Monitoring of Intracranial Pressure in Patients with Traumatic Brain Injury

    PubMed Central

    Hawthorne, Christopher; Piper, Ian

    2014-01-01

    Since Monro published his observations on the nature of the contents of the intracranial space in 1783, there has been investigation of the unique relationship between the contents of the skull and the intracranial pressure (ICP). This is particularly true following traumatic brain injury (TBI), where it is clear that elevated ICP due to the underlying pathological processes is associated with a poorer clinical outcome. Consequently, there is considerable interest in monitoring and manipulating ICP in patients with TBI. The two techniques most commonly used in clinical practice to monitor ICP are via an intraventricular or intraparenchymal catheter with a microtransducer system. Both of these techniques are invasive and are thus associated with complications such as hemorrhage and infection. For this reason, significant research effort has been directed toward development of a non-invasive method to measure ICP. The principle aims of ICP monitoring in TBI are to allow early detection of secondary hemorrhage and to guide therapies that limit intracranial hypertension (ICH) and optimize cerebral perfusion. However, information from the ICP value and the ICP waveform can also be used to assess the intracranial volume–pressure relationship, estimate cerebrovascular pressure reactivity, and attempt to forecast future episodes of ICH. PMID:25076934

  12. Continuous measurement of intracranial pressure with SFT: clinical experiences.

    PubMed

    Yoneda, S; Matsuda, M; Handa, J; Handa, H

    1975-09-01

    In 29 consecutive patients, the epidural intracranial pressure (EDP) was continuously measured with a semiconductor strain film transducer, and with a telemetric monitoring system in two patients. Factors affecting the EDP during pre-, intra- and postoperative periods were analyzed and their significance in clinical practice stressed.

  13. Orbital and Intracranial Effects of Microgravity: 3T MRI Findings

    NASA Technical Reports Server (NTRS)

    Kramer, L. A.; Sargsyan, A.; Hasan, K. M.; Polk, J. D.; Hamilton, D. R.

    2012-01-01

    Goals and Objectives of this presentation are: 1. To briefly describe a newly discovered clinical entity related to space flight. 2. To describe normal anatomy and pathologic changes of the optic nerve, posterior globe, optic nerve sheath and pituitary gland related to exposure to microgravity. 3. To correlate imaging findings with known signs of intracranial hypertension.

  14. Vessel Wall Imaging of the Intracranial and Cervical Carotid Arteries

    PubMed Central

    Choi, Young Jun; Jung, Seung Chai; Lee, Deok Hee

    2015-01-01

    Vessel wall imaging can depict the morphologies of atherosclerotic plaques, arterial walls, and surrounding structures in the intracranial and cervical carotid arteries beyond the simple luminal changes that can be observed with traditional luminal evaluation. Differentiating vulnerable from stable plaques and characterizing atherosclerotic plaques are vital parts of the early diagnosis, prevention, and treatment of stroke and the neurological adverse effects of atherosclerosis. Various techniques for vessel wall imaging have been developed and introduced to differentiate and analyze atherosclerotic plaques in the cervical carotid artery. High-resolution magnetic resonance imaging (HR-MRI) is the most important and popular vessel wall imaging technique for directly evaluating the vascular wall and intracranial artery disease. Intracranial artery atherosclerosis, dissection, moyamoya disease, vasculitis, and reversible cerebral vasoconstriction syndrome can also be diagnosed and differentiated by using HR-MRI. Here, we review the radiologic features of intracranial artery disease and cervical carotid artery atherosclerosis on HR-MRI and various other vessel wall imaging techniques (e.g., ultrasound, computed tomography, magnetic resonance, and positron emission tomography-computed tomography). PMID:26437991

  15. [Intraoperative localization of space-occupying intracranial processes using ultrasound].

    PubMed

    Raghavendra, B N; Epstein, F J; Cooper, P R; Horii, S C; Ransohoff, J

    1984-10-01

    During a two-year period, intra-operative ultrasonic explorations were performed in 44 patients for the purpose of localisation of intracranial masses. This facilitated accurate intraoperative assessment of the location and consistency of the mass. We consider operative ultrasound to be an invaluable adjunct to surgery of small intracerebral masses.

  16. /sup 123/I-metaiodobenzylguanidine scintigraphy of ectopic intracranial retinoblastoma

    SciTech Connect

    Bomanji, J.; Kingston, J.E.; Hungerford, J.L.; Britton, K.E.

    1989-01-01

    Radioiodinated metaiodobenzylguanidine (MIBG) has been used for diagnostic purposes to image neural crest tumors. We report the uptake of /sup 123/I MIBG in a child with ectopic intracranial retinoblastoma. It is felt that /sup 123/I MIBG scintigraphy may have a role in detecting occult metastatic disease in these patients.

  17. Asymptomatic Intracranial Foreign Body: An Incidental Finding on Radiography

    PubMed Central

    Maghsoudi, Mohammadreza; Shahbazzadegan, Bita; Pezeshki, Arastoo

    2016-01-01

    Introduction Intracranial needles are rare entities. Intracranial foreign bodies due to non-missile intracranial penetrations are one of the most rarely encountered situations in neurosurgery. Sewing needles are among the more unusual foreign bodies that may be found in the brain. Although uncommon, foreign body cases are important and interesting. Foreign bodies enter the body through trauma or iatrogenic injuries. Needles are mostly inserted through fontanelles, cranial sutures, and more rarely through the orbits in infancy for the purpose of killing unwanted babies. Case Presentation This article presents a case of intracranial foreign body found upon radiography. A 24-year-old female, who two days prior to presentation suffered only once from dizziness, and was otherwise healthy. Conclusions Because this incident may have occurred during the patient’s neonatal period, it may be a case of child abuse. In spite of the very limited number of cases in the literature, having a stepmother, a stepfather, or a babysitter, being the youngest child, or having family members who suffer from psychiatric disorders, (especially if these relatives are responsible for child care), living in a society that allows homicide of children born from extramarital relationships, and being female have been suggested as possible risk factors. PMID:27626006

  18. Diagnosing intracranial vasculitis: The roles of MR and angiography

    SciTech Connect

    Harris, K.G.; Tran, D.D.; Sickels, W.J.; Cornell, S.H.; Yuh, W.T.C. )

    1994-02-01

    To describe our experience with MR and angiography in diagnosing intracranial vasculitis and to test the hypothesis that MR can be used to screen for patients unlikely to have vasculitis. Ninety-two patients who had angiography with [open quotes]exclude vasculitis[close quotes] as the indication or who had angiography and a clinical diagnosis of vasculitis were identified. Angiograms of all 92 patients and the MRs of the 70 patients who had both studies were reviewed. Eleven patients had intracranial vasculitis. Angiography showed characteristic changes in 8. MR performed in 9 of 11 vasculitis cases, was significantly abnormal in all 9. Among 70 patients who had both studies, 19 had MR that was completely normal or showed only incidental findings. None of these 19 was diagnosed with vasculitis. The diagnostic yield of angiography performed to exclude vasculitis was only 6%. Evaluation for intracranial vasculitis should include MR. A negative MR excludes intracranial vasculitis more definitively than does a negative angiogram and makes the likelihood of finding vasculitis with angiography negligible. 23 refs., 5 figs., 4 tabs.

  19. Asymptomatic Intracranial Foreign Body: An Incidental Finding on Radiography

    PubMed Central

    Maghsoudi, Mohammadreza; Shahbazzadegan, Bita; Pezeshki, Arastoo

    2016-01-01

    Introduction Intracranial needles are rare entities. Intracranial foreign bodies due to non-missile intracranial penetrations are one of the most rarely encountered situations in neurosurgery. Sewing needles are among the more unusual foreign bodies that may be found in the brain. Although uncommon, foreign body cases are important and interesting. Foreign bodies enter the body through trauma or iatrogenic injuries. Needles are mostly inserted through fontanelles, cranial sutures, and more rarely through the orbits in infancy for the purpose of killing unwanted babies. Case Presentation This article presents a case of intracranial foreign body found upon radiography. A 24-year-old female, who two days prior to presentation suffered only once from dizziness, and was otherwise healthy. Conclusions Because this incident may have occurred during the patient’s neonatal period, it may be a case of child abuse. In spite of the very limited number of cases in the literature, having a stepmother, a stepfather, or a babysitter, being the youngest child, or having family members who suffer from psychiatric disorders, (especially if these relatives are responsible for child care), living in a society that allows homicide of children born from extramarital relationships, and being female have been suggested as possible risk factors.

  20. Intracranial Hemodynamic Changes During Adult Moyamoya Disease Progression

    PubMed Central

    Kwag, Hyun-Jeong; Jeong, Dong-Wook; Lee, Suk Hoon; Kim, Dae Hyun

    2008-01-01

    Background and purpose This study evaluated the changes in blood flow velocity in the anterior and posterior intracranial circulations according to the progression of moyamoya disease in adult patients. Methods We evaluated Suzuki's angiographic stage and mean blood flow velocity (MBFV) changes in intracranial vessels from both sides in 19 adult moyamoya patients. We then analyzed the linearity of MBFV changes from early to late moyamoya stages in each intracranial vessel using piecewise linear regression models. Results The MBFV in the middle cerebral artery, terminal internal carotid artery, and anterior cerebral artery increased non linearly until stage III, and then decreased progressively up to stage VI. The ophthalmic artery also showed nonlinear velocity changes, with an increase in MBFV up to stage IV, followed by a decrease in MBFV up to stage VI. The MBFV of the basilar artery increased linearly from a normal velocity at an early moyamoya stage to a stenotic velocity at a late stage. There was no statistically significant regression model for the relationship between the MBFV in the posterior cerebral artery and moyamoya stage. Conclusions The nonlinear and/or linear MBFV changes associated with variable intracranial vessels might be useful in initial and follow-up evaluations of different stages of moyamoya disease. PMID:19513306

  1. Intracranial extramedullary hematopoiesis. CT and bone marrow scan findings

    SciTech Connect

    Urman, M.; O'Sullivan, R.A.; Nugent, R.A.; Lentle, B.C. )

    1991-06-01

    This case concerns a patient with intracranial extramedullary hematopoiesis (EH) suspected on a CT scan and subsequently confirmed with In-111 chloride and Tc-99m SC bone marrow scans. The bone marrow scans also provided additional information by demonstrating other sites of EH in the paravertebral tissues and bone marrow expansion into the distal extremities.

  2. Storage Ring EDM Experiments

    NASA Astrophysics Data System (ADS)

    Semertzidis, Yannis K.

    2016-04-01

    Dedicated storage ring electric dipole moment (EDM) methods show great promise advancing the sensitivity level by a couple orders of magnitude over currently planned hadronic EDM experiments. We describe the present status and recent updates of the field.

  3. Highlights in planetary rings

    NASA Astrophysics Data System (ADS)

    Porco, Carolyn C.

    1995-07-01

    There is a rich phenomenology within the planetary rings surrounding the giant planets, most of it discovered by the Voyagers during their historic tours of t he outer solar system in the 1980s. In the last decade, there have been two detailed IUGG reviews of planetary rings. Cuzzi [1983] covered the time period from 1979-1983 which included the Pioneer 11 encounter with Saturn (1979), the Voyager 1 and 2 encounters with Jupiter (1979) and with Saturn (1980 and 1981). Nicholson and Dones [1991] reviewed the developments in the field between 1984 and 1991, a period of time which included the Voyager 2 Uranus (1986) and Neptune (1989) encounters. (References t o additional reviews of planetary rings and related fields can be found in Nicholson and Dones [1991].) Rather than being comprehensive in nature, this review will concentrate on only those areas of ring research in which particularly promising developments have occurred in the last half decade.

  4. Heating Saturn's Clumpy Rings

    NASA Astrophysics Data System (ADS)

    Turner, Neal J.; Morishima, Ryuji; Spilker, Linda J.

    2015-11-01

    We model Cassini CIRS data using a Monte Carlo radiative transfer -- thermal balance technique first developed for protostellar disks, with the goals of:1. Exploring whether the A- and B-ring temperatures' variation with viewing angle is consistent with the wake structures suggested by the observed azimuthal asymmetry in optical depth, by analytic arguments, and by numerical N-body modeling.2. Better constraining the shape, size, spacing and optical depths of substructure in the A-ring, using the unexpectedly high temperatures observed at equinox. If the wake features have high enough contrast, Saturn-shine may penetrate the gaps between the wakes and heat thering particles both top and bottom.3. Determining how much of the heating of the A- and B-rings' unlit sides is due to radiative transport and how much is due to particle motions, especially vertical motions. This will help in constraining the rings' surface densities and masses.

  5. Giant Intracranial Aneurysm in a Ten-Year-Old Boy with Parry Romberg Syndrome

    PubMed Central

    Bosman, T.; Van Beijnum, J.; Van Walderveen, M.A.A.; Brouwer, P.A.

    2009-01-01

    Summary Parry-Romberg syndrome (PRS) is a rare acquired syndrome consisting of progressive hemiatrophy of the face. We present a child with PRS and progressive neurological deficit caused by a giant intracranial aneurysm and reviewed the literature concerning all intracranial abnormalities in patients with PRS. A literature search identified 27 articles reporting on 88 patients with PRS and intracranial abnormalities. Ipsilateral brain calcification and hemiatrophy are the most prominent features on CT scan and hyperintense white matter lesions are most frequently seen on T2-weighted MRI. Although lacking precise prevalence data, intracranial abnormalities are not uncommon in patients with PRS. We found three other PRS patients with intracranial aneurysms. Our case and literature search suggests a possible association between PRS and intracranial aneurysms. We consider this association important for clinical practice and recommend including intracranial vascular diseases in the differential diagnosis when dealing with a PRS patient with neurological symptoms. PMID:20465894

  6. Nocturnal ultrasound measurements of optic nerve sheath diameter correlate with intracranial pressure in children with craniosynostosis.

    PubMed

    Driessen, Caroline; van Veelen, Marie-Lise C; Lequin, Maarten; Joosten, Koen F M; Mathijssen, Irene M J

    2012-09-01

    Children with craniosynostosis are at risk for increased intracranial pressure, and additional possibilities to screen for increased intracranial pressure are required. The authors' aim was to use ultrasound measurements of the optic nerve sheath to understand and express the variability of intracranial pressure in syndromic craniosynostosis. Therefore, five pediatric patients with craniosynostosis underwent invasive 24-hour intracranial pressure monitoring and simultaneous optic nerve sheath measurements. In three patients, the intracranial pressure was abnormal, and during the second half of the night, the optic nerve sheath was increased in all three patients. The optic nerve sheath diameter changes during the night and is as dynamic as the intracranial pressure. To the best of their knowledge, the authors are the first to describe a real-time relationship of the optic nerve sheath with increased intracranial pressure in children.

  7. Saturn's dynamic D ring

    USGS Publications Warehouse

    Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.

    2007-01-01

    The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to a much broader and more diffuse 250-km wide feature. In addition, its center of light has shifted inwards by over 200 km relative to other features in the D ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

  8. Ultrasonic Newton's rings

    SciTech Connect

    Hsu, D.K. ); Dayal, V. )

    1992-03-09

    Interference fringes due to bondline thickness variation were observed in ultrasonic scans of the reflected echo amplitude from the bondline of adhesively joined aluminum skins. To demonstrate that full-field interference patterns are observable in point-by-point ultrasonic scans, an optical setup for Newton's rings was scanned ultrasonically in a water immersion tank. The ultrasonic scan showed distinct Newton's rings whose radii were in excellent agreement with the prediction.

  9. Hyponatremia with intracranial malignant tumor resection in children

    PubMed Central

    Williams, Cydni; Simon, Tamara D.; Riva-Cambrin, Jay; Bratton, Susan L.

    2012-01-01

    Object Intracranial neoplasms are the second most common childhood cancer, and lead to significant morbidity and mortality. Hyponatremia is a complication associated with neurosurgical procedures, but children undergoing intracranial tumor resection have not been selectively studied. In this study, the authors aimed to determine the incidence and risk factors associated with hyponatremia among children undergoing intracranial neoplasm resection. Methods A retrospective cohort was compiled using the 2006 Kids' Inpatient Database to identify children younger than 21 years of age who underwent intracranial neoplasm resection. Hyponatremia was ascertained by diagnosis codes. Bivariate analyses were conducted using chi-square and Mann-Whitney U-tests. Logistic regression models were developed to evaluate factors associated with hyponatremia in bivariate analyses. Results Hyponatremia occurred in 205 (8.7%) of 2343 annual weighted cases, and was independently associated with tumor location in the deep brain structures and ventricles compared with the cortical area (adjusted odds ratio [aOR] 2.4; 95% CI 1.17–5.3). Hyponatremia was also associated with obstructive hydrocephalus (aOR 2.7; 95% CI 1.7–4.3) and emergency department admission (aOR 1.7; 95% CI 1.1–2.4). Hyponatremia was significantly associated with mechanical ventilation, ventriculostomy placement, ventriculoperitoneal shunt placement, and sepsis. Hyponatremia was also associated with a significantly longer average length of stay (24.6 vs 10.2 days), higher average charges ($191,000 vs $92,000), and a higher percentage of discharges to intermediate-care facilities. Conclusions Hyponatremia commonly occurs with resection of intracranial malignant tumors, especially for lesions located in the deep brain and in patients with obstructive hydrocephalus. Hyponatremia was associated with higher morbidity. Further research is needed to develop targeted monitoring and intervention strategies to decrease

  10. Extracranial and intracranial vertebrobasilar dissections: diagnosis and prognosis

    PubMed Central

    de Bray, J M; Penisson-Besnier, I; Dubas, F; Emile, J

    1997-01-01

    OBJECTIVES—To compare the diagnosis and prognosis of extracranial versus intracranial vertebral artery dissections without intracerebral haemorrhage.
METHODS—Twenty two vertebral artery dissections were defined by intra-arterial angiography and classified in two groups: group 1,nine extracranial dissections (seven patients) and group 2, 13intracranial dissections (nine patients), involving the basilar artery in five cases. Bilateral dissections were found in 38% of the population. Before angiography, all the patients had been investigated by continuous wave Doppler, colour coded Doppler, and transcranial Doppler. Mean follow up was 44months.
RESULTS—The two most important symptoms of both dissections (81% of patients) were unbearable pain preceding stroke and progressive onset of stroke within a few hours. Severe ultrasonic abnormalities were present in 94% of the patients whereas specific ultrasonic signs (segmental dilation with eccentric channel) were rare (19%) in both groups. Major strokes and brainstem strokes represented respectively 67% and 78% in intracranial versus 43% and 29% in extracranial dissections. Severe sequelae (permanent disabling motor or cerebellar deficit) were more often associated with intracranial (44%) than with extracranial dissections (14%). No recurrence of dissection and no cerebral haemorrhage were found under heparin. Significant factors of poor outcome (P< 0.05) were the initial severity of the stroke and the bilateral location of dissections.
CONCLUSION—The combination of a pain and a progressive onset of the stroke, corroborated by ultrasonic findings, could have helped to recognise most of these types of dissections. Intracranial dissections have a poorer prognosis than extracranial dissections.

 PMID:9221967

  11. Primary intracranial neuroendocrine tumor with ectopic adrenocorticotropic hormone syndrome: A rare and complicated case report and literature review

    PubMed Central

    LIU, HAILONG; ZHANG, MINGSHAN; WANG, XUAN; QU, YANMING; ZHANG, HONGWEI; YU, CHUNJIANG

    2016-01-01

    Neuroendocrine tumors (NETs) and ectopic adrenocorticotropic hormone (ACTH) syndrome are frequent in adult patients. However, primary intracranial NETs, exhibiting immunonegativity for ACTH, high serum ACTH level and treated with anterior skull base reconstruction, are rare and complicated. We herein present a case of a primary intracranial NET immunonegative for ACTH, resulting in ectopic ACTH syndrome. A 40-year-old woman presented with intermittent rhinorrhea, rapid weight gain, polydipsia, polyuria, hypertension, dimness, bilateral exophthalmus, diminution of vision in the left eye and pigmentation of the skin of the face and trunk. Computed tomography (CT) and magnetic resonance imaging scans revealed a sizeable enhancing tumor in the anterior cranial fossa, which infiltrated the sphenoid and ethmoid sinuses bilaterally, the left maxillary sinus and the nasal cavity. Abdominal CT scans revealed bilateral adrenal hyperplasia. The biochemical findings included hypokalemia and high glucose, cortisol, plasma ACTH, 24-h urinary free cortisol and testosterone levels. The neoplasm was exposed through a right frontal craniotomy, while anterior skull base reconstruction was performed during surgery. The intracranial surgery achieved gross removal of the tumor; however, part of the tumor remained in the nasal cavity. Histopathological examination of the surgical specimen confirmed the diagnosis of a low-grade small-cell NET, exhibiting immunonegativity for ACTH. A postoperative abdominal CT scan demonstrated bilateral regression of the adrenal gland hyperplasia and the serum ACTH level returned to normal after 16 days. To the best of our knowledge, there are no previous reports of primary intracranial NETs, immunohistochemically negative for ACTH, resulting in ectopic ACTH syndrome. PMID:27330775

  12. Fast circulation of cerebrospinal fluid: an alternative perspective on the protective role of high intracranial pressure in ocular hypertension.

    PubMed

    Wostyn, Peter; De Groot, Veva; Van Dam, Debby; Audenaert, Kurt; Killer, Hanspeter Esriel; De Deyn, Peter Paul

    2016-05-01

    As ocular hypertension refers to a condition in which the intraocular pressure is consistently elevated but without development of glaucoma, study of it may provide important clues to factors that may play a protective role in glaucoma. β-amyloid, one of the key histopathological findings in Alzheimer's disease, has been reported to increase by chronic elevation of intraocular pressure in animals with experimentally induced ocular hypertension and to cause retinal ganglion cell death, pointing to similarities in molecular cell death mechanisms between glaucoma and Alzheimer's disease. On the other hand, recent studies have reported that intracranial pressure is higher in patients with ocular hypertension compared with controls, giving rise to the idea that elevated intracranial pressure may provide a protective effect for the optic nerve by decreasing the trans-lamina cribrosa pressure difference. The speculation that the higher intracranial pressure reported in ocular hypertension patients may protect against glaucoma mainly through a lower trans-lamina cribrosa pressure difference remains at least questionable. Here, we present an alternative viewpoint, according to which the protective effect of higher intracranial pressure could be due, at least in part, to a pressure-independent mechanism, namely faster cerebrospinal fluid production leading to increased cerebrospinal fluid turnover with enhanced removal of potentially neurotoxic waste products that accumulate in the optic nerve. This suggests a new hypothesis for glaucoma, which, just like Alzheimer's disease, may be considered then as an imbalance between production and clearance of neurotoxins, including β-amyloid. If confirmed, then strategies to improve cerebrospinal fluid flow are reasonable and could provide a new therapeutic approach for stopping the neurotoxic β-amyloid pathway in glaucoma.

  13. Fast circulation of cerebrospinal fluid: an alternative perspective on the protective role of high intracranial pressure in ocular hypertension.

    PubMed

    Wostyn, Peter; De Groot, Veva; Van Dam, Debby; Audenaert, Kurt; Killer, Hanspeter Esriel; De Deyn, Peter Paul

    2016-05-01

    As ocular hypertension refers to a condition in which the intraocular pressure is consistently elevated but without development of glaucoma, study of it may provide important clues to factors that may play a protective role in glaucoma. β-amyloid, one of the key histopathological findings in Alzheimer's disease, has been reported to increase by chronic elevation of intraocular pressure in animals with experimentally induced ocular hypertension and to cause retinal ganglion cell death, pointing to similarities in molecular cell death mechanisms between glaucoma and Alzheimer's disease. On the other hand, recent studies have reported that intracranial pressure is higher in patients with ocular hypertension compared with controls, giving rise to the idea that elevated intracranial pressure may provide a protective effect for the optic nerve by decreasing the trans-lamina cribrosa pressure difference. The speculation that the higher intracranial pressure reported in ocular hypertension patients may protect against glaucoma mainly through a lower trans-lamina cribrosa pressure difference remains at least questionable. Here, we present an alternative viewpoint, according to which the protective effect of higher intracranial pressure could be due, at least in part, to a pressure-independent mechanism, namely faster cerebrospinal fluid production leading to increased cerebrospinal fluid turnover with enhanced removal of potentially neurotoxic waste products that accumulate in the optic nerve. This suggests a new hypothesis for glaucoma, which, just like Alzheimer's disease, may be considered then as an imbalance between production and clearance of neurotoxins, including β-amyloid. If confirmed, then strategies to improve cerebrospinal fluid flow are reasonable and could provide a new therapeutic approach for stopping the neurotoxic β-amyloid pathway in glaucoma. PMID:26691953

  14. Nardo Ring, Italy

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Nardo Ring is a striking visual feature from space, and astronauts have photographed it several times. The Ring is a race car test track; it is 12.5 kilometers long and steeply banked to reduce the amount of active steering needed by drivers. The Nardo Ring lies in a remote area on the heel of Italy's 'boot,' 50 kilometers east of the naval port of Taranto. The Ring encompasses a number of active (green) and fallow (brown to dark brown) agricultural fields. In this zone of intensive agriculture, farmers gain access to their fields through the Ring via a series of underpasses. Winding features within the southern section of the Ring appear to be smaller, unused race tracks.

    The image covers an area of 18.8 x 16.4 km, was acquired on August 17. 2007, and is located at 49.3 degrees north latitude, 17.8 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  15. Angioleiomyoma, a rare intracranial tumor: 3 case report and a literature review

    PubMed Central

    2014-01-01

    Three cases of intracranial angioleiomyoma (ALM) in our neurosurgery center are reported in detail. ALM is a benign soft tissue tumor comprised of mature smooth muscle cells and a prominent vascular component, which is extremely rare as a primary intracranial lesion. Altogether, only 12 cases were recorded in the literature to date, to the best of our knowledge. Case 1 is the second report of intra-sella ALM, a 51-year-old woman presented with visual deterioration for 2 months. An MRI showed an intra-sella 3-cm tumor, partially flame-like, enhanced with gadolinium. Using microscopic endonasal transsphenoidal approach, the tumor was completely resected with great difficulty. At 11 days post-surgery, she died of a sudden catastrophic nasal hemorrhage. An angiography revealed a pseudo-aneurysm of ICA (internal carotid artery). Case 2 is a 49-year-old man who presented with weakness of the lower limbs for 1 year. A large subtentorial mass was found affixed to the torcular and straight sinus, which was partially flame-like, dramatically enhanced as in case 1. Case 3 is that of a 77-year-old man. An ALM mass was revealed in the diploe of left temporal bone, and had eroded the inner table. Immunohistochemical workup confirmed the diagnosis of angioleiomyoma in all 3 cases. The radiology, operation, and complication of surgery in each case were discussed. In conclusion, intracranial ALMs are extremely rare, usually located ex-neuro axis (such as in our cases), in the sella, in posterior fossa, or in the skull. Magnetic resonance imaging (MRI) revealed a special feature of flame-like partial enhancement that may be helpful to distinguish ALM from pituitary tumors or meningiomas, and should result in the consideration of this rare tumor entity early on in the diagnostic process. A definitive diagnosis depends on histological analyses. The resection of ALM in certain locations is difficult and risky because of the rich blood supply. PMID:25027207

  16. Recent Hubble Observations of Jupiter's Ring System

    NASA Astrophysics Data System (ADS)

    Showalter, M. R.; Burns, J. A.; de Pater, I.; Hamilton, D. P.; Horanyi, M.

    2003-05-01

    The period December 2002 through February 2003 provided a rare opportunity to watch Jupiter sweep through its full range of Earth-based phase angles while the rings remained nearly edge-on to Earth. We used this period for a series of Jovian ring observations using the High Resolution Channel (HRC) of Hubble's new Advanced Camera for Surveys (ACS). Phase angles span 0.17o--10o. Our images showed the main ring, Adrastea and Metis with very high signal-to-noise ratios (SNR). Amalthea's gossamer ring was detected (and vertically resolved) in a small set of specially targeted images. Somewhat surprisingly, we have not yet been able to detect the halo in any of our images, perhaps because it is obscured by the scattered light from Jupiter's disk, positioned just 4'' outside the HRC's field of view. Preliminary results from this data set are as follows. (1) The ring is substantially less red than the moons, suggesting that fine dust represents a significant fraction of its backscattering intensity. (2) Neither the rings nor the embedded moons Metis and Adrastea have significant opposition surges. We were hoping to use the surge, which is characteristic of most macroscopic bodies but not dust, as an indicator of where any embedded ring parent bodies might reside. (3) Because our data are so sensitive to Metis (radius ˜ 20 km) and Adrastea ( ˜ 8 km), we believe that bodies as small as 3--4 km in radius should have been detected in the data. In an initial search, no additional bodies have been detected. (4) The Amalthea ring shows an enhancement in brightness in its outermost 15,000 km. This is consistent with what was seen in Galileo images at very high phase angles. Support for this work was provided by NASA through the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555.

  17. MR of intracranial tumors: Combined use of gadolinium and magnetization transfer

    SciTech Connect

    Kurki, T.; Niemi, P.; Valtonen, S.

    1994-10-01

    To study the potential combined application of gadolinium and magnetization transfer in the MR imaging of intracranial tumors. Twenty-two patients were imaged at low field strength (0.1 T). Corresponding gradient-echo partial saturation images without and with magnetization transfer pulse were produced. Images with intermediate repetition times were obtained in 18 cases; five different sequences were produced in 4 cases. Gadopentetate dimeglumine was used at a dose of 0.1 mmol/kg. Magnetization transfer effect increased the contrast between enhancing lesion and normal brain and the contrast between edema and normal brain; the contrast between enhancing lesion and edema was not significantly changed. On intermediate-repetition-time magnetization transfer images the contrast between enhancing tumor and normal brain and the contrast between edema and normal brain were superior to short-repetition-time magnetization transfer images, but the differentiation between enhancing tumor and edema was poorer. Magnetization transfer can be used to improve contrast in Gd-enhanced MR imaging. Combining magnetization transfer with an intermediate-repetition-time image provides the possibility for displaying both enhancing and nonehancing lesions on a single MR image. 20 refs., 7 figs., 2 tabs.

  18. Propellers in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2014-04-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings [5, 8]. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~ 100m in size) have been identified in Saturn's A ring through their propeller signature in the images [10, 7, 9, 11]. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring [6, 2]. In this paper we present our new results about by now classical A ring propellers and more enigmatic B ring population. Due to the presence of self-gravity wakes the analysis of propeller brightness in ISS images always bears some ambiguity [7, 9] and consequently the exact morphology of propellers is not a settled issue. In 2008 we obtained a fortunate Cassini Ultraviolet Imaging Spectrograph (UVIS) occultation of the largest A ring propeller Bleriot. Utilizing Cassini ISS images we obtain Bleriot orbit and demonstrate that UVIS Persei Rev42 occultation did cut across Bleriot about 100km downstream from the center. The occultation itself shows a prominent partial gap and higher density outer flanking wakes, while their orientation is consistent with a downstream cut. While in the UVIS occultation the partial gap is more prominent than the flanking wakes, the features mostly seen in Bleriot images are actually flanking wakes. One of the most interesting aspects of the A ring propellers are their wanderings, or longitudinal deviations from a pure circular orbit [11]. We numerically investigated the possibility of simple moon

  19. Retaining-Ring Installation Tool

    NASA Technical Reports Server (NTRS)

    Christian, S.

    1983-01-01

    New tool eliminates damage to ring through improper tool use. Tool installs spiral-wound retaining rings quickly, reliably, and safely. Tool inserts rings in splined or irregularly shaped bores, bores at bottom of deep ring and slides it along bore until it nests in groove. Pistons are moved by variety of linkages.

  20. Thermodynamic black di-rings

    SciTech Connect

    Iguchi, Hideo; Mishima, Takashi

    2010-10-15

    Previously the five dimensional S{sup 1}-rotating black rings have been superposed in a concentric way by some solitonic methods, and regular systems of two S{sup 1}-rotating black rings were constructed by the authors and then Evslin and Krishnan (we called these solutions 'black di-rings'). In this place we show some characteristics of the solutions of five dimensional black di-rings, especially in thermodynamic equilibrium. After the summary of the di-ring expressions and their physical quantities, first we comment on the equivalence of the two different solution sets of the black di-rings. Then the existence of thermodynamic black di-rings is shown, in which both isothermality and isorotation between the inner black ring and the outer black ring are realized. We also give detailed analysis of peculiar properties of the thermodynamic black di-ring including discussion about a certain kind of thermodynamic stability (instability) of the system.

  1. Propellers in Saturn's rings

    NASA Astrophysics Data System (ADS)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~<500m in size) have been indirectly identified in Saturn's A ring through their propeller signature in the images. Furthermore, recent Cassini observations indicate the possible existence of objects embedded even in Saturn's B and C ring. In this paper we present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B

  2. Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    NASA Astrophysics Data System (ADS)

    Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

    2010-10-01

    Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  3. Saturn's Other Ring Current

    NASA Astrophysics Data System (ADS)

    Crary, F. J.

    2014-04-01

    Saturn's main rings orbit the planet within an atmosphere and ionosphere of water, oxygen and hydrogen, produced by meteoritic impacts on and ultraviolet photodesorbtion of the ring particles [Johnson et al., 2006; Luhmann et al., 2006; Tseng et al., 2010]. The neutral atmosphere itself has only been tentatively detected through ultraviolet fluorescents of OH [Hall et al., 1996] while the ionosphere was observed in situ by the Cassini spacecraft shortly after orbital insertion [Coates et al.,2005; Tokar et al. 2005, Waite et al. 2005]. Although the plasma flow velocity of this ionosphere is not well-constrained, but the close association with the rings suggests that its speed would be couppled to the keplarian velocity of the rings themselves. As a result, the motion of the plasma through Saturn's magnetic field would produce an induced voltage, oriented away from the planet outside synchronous orbit and towards the planet inside synchronous orbit. Such a potential could result in currents flowing across the ring plane and closeing along magnetic field lines and through Saturn's ionosphere at latitudes between 36o and 48o. Cassini observations of whistler-mode plasma wave emissions [Xin et al.,2006] centered on synchronous orbit (1.76 Rs, mapping to 41o latitude) have been interpreted as a product of field-aligned electron beams associated with such a current. This presentation will investigate the magnitude of these currents and the resulting Joule heating of the ionosphere. An important constraint is that no auroral ultraviolet emissions have been observed at the relevant latitudes. In contrast, Joule heating could affect infrared emissions from H3+. Variations in H3+ emission associated with Saturn's rings have been reported by O'Donoghue et al., 2013, and interpreted as a result of ring "rain", i.e. precipitating water group species from the rings which alter ionosphereic chemistry and H3+ densities. As noted by O'Donoghue et al., this interpretation may be

  4. Piston Ring Pressure Distribution

    NASA Technical Reports Server (NTRS)

    Kuhn, M.

    1943-01-01

    The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses, Of these internal engine components, the piston and piston rings are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the components, The piston ring is a well-known component and has been used in its present shape in the steam engine of the last century, Corresponding to its importance, the piston ring has been a rich field for creative activity and it is noteworthy that in spite of this the ring has maintained its shape through the many years. From the many and complicated designs which have been suggested as a packing between piston and cylinder wall hardly one suggestion has remained which does not resemble the original design of cast iron rectangular ring.

  5. Stacked Corrugated Horn Rings

    NASA Technical Reports Server (NTRS)

    Sosnowski, John B.

    2010-01-01

    This Brief describes a method of machining and assembly when the depth of corrugations far exceeds the width and conventional machining is not practical. The horn is divided into easily machined, individual rings with shoulders to control the depth. In this specific instance, each of the corrugations is identical in profile, and only differs in diameter and outer profile. The horn is segmented into rings that are cut with an interference fit (zero clearance with all machining errors biased toward contact). The interference faces can be cut with a reverse taper to increase the holding strength of the joint. The taper is a compromise between the interference fit and the clearance of the two faces during assembly. Each internal ring is dipped in liquid nitrogen, then nested in the previous, larger ring. The ring is rotated in the nest until the temperature of the two parts equalizes and the pieces lock together. The resulting assay is stable, strong, and has an internal finish that cannot be achieved through other methods.

  6. Two F Ring Views

    NASA Technical Reports Server (NTRS)

    2005-01-01

    These views, taken two hours apart, demonstrate the dramatic variability in the structure of Saturn's intriguing F ring.

    In the image at the left, ringlets in the F ring and Encke Gap display distinctive kinks, and there is a bright patch of material on the F ring's inner edge. Saturn's moon Janus (181 kilometers, or 113 miles across) is shown here, partly illuminated by reflected light from the planet.

    At the right, Prometheus (102 kilometers, or 63 miles across) orbits ahead of the radial striations in the F ring, called 'drapes' by scientists. The drapes appear to be caused by successive passes of Prometheus as it reaches the greatest distance (apoapse) in its orbit of Saturn. Also in this image, the outermost ringlet visible in the Encke Gap displays distinctive bright patches.

    These views were obtained from about three degrees below the ring plane.

    The images were taken in visible light with the Cassini spacecraft narrow-angle camera on June 29, 2005, when Cassini was about 1.5 million kilometers (900,000 miles) from Saturn. The image scale is about 9 kilometers (6 miles) per pixel.

  7. The pepper E3 ubiquitin ligase RING1 gene, CaRING1, is required for cell death and the salicylic acid-dependent defense response.

    PubMed

    Lee, Dong Hyuk; Choi, Hyong Woo; Hwang, Byung Kook

    2011-08-01

    Ubiquitination is essential for ubiquitin/proteasome-mediated protein degradation in plant development and defense. Here, we identified a novel E3 ubiquitin ligase RING1 gene, CaRING1, from pepper (Capsicum annuum). In pepper, CaRING1 expression is induced by avirulent Xanthomonas campestris pv vesicatoria infection. CaRING1 contains an amino-terminal transmembrane domain and a carboxyl-terminal RING domain. In addition, it displays in vitro E3 ubiquitin ligase activity, and the RING domain is essential for E3 ubiquitin ligase activity in CaRING1. CaRING1 also localizes to the plasma membrane. In pepper plants, virus-induced gene silencing of CaRING1 confers enhanced susceptibility to avirulent X. campestris pv vesicatoria infection, which is accompanied by compromised hypersensitive cell death, reduced expression of PATHOGENESIS-RELATED1, and lowered salicylic acid levels in leaves. Transient expression of CaRING1 in pepper leaves induces cell death and the defense response that requires the E3 ubiquitin ligase activity of CaRING1. By contrast, overexpression of CaRING1 in Arabidopsis (Arabidopsis thaliana) confers enhanced resistance to hemibiotrophic Pseudomonas syringae pv tomato and biotrophic Hyaloperonospora arabidopsidis infections. Taken together, these results suggest that CaRING1 is involved in the induction of cell death and the regulation of ubiquitination during the defense response to microbial pathogens.

  8. Borderline Intracranial Hypertension Manifesting as Chronic Fatigue Syndrome Treated by Venous Sinus Stenting.

    PubMed

    Higgins, Nicholas; Pickard, John; Lever, Andrew

    2015-11-01

    Chronic fatigue syndrome and cases of idiopathic intracranial hypertension without signs of raised intracranial pressure can be impossible to distinguish without direct measurement of intracranial pressure. Moreover, lumbar puncture, the usual method of measuring intracranial pressure, can produce a similar respite from symptoms in patients with chronic fatigue as it does in idiopathic intracranial hypertension. This suggests a connection between them, with chronic fatigue syndrome representing a forme fruste variant of idiopathic intracranial hypertension. If this were the case, then treatments available for idiopathic intracranial hypertension might be appropriate for chronic fatigue. We describe a 49-year-old woman with a long and debilitating history of chronic fatigue syndrome who was targeted for investigation of intracranial pressure because of headache, then diagnosed with borderline idiopathic intracranial hypertension after lumbar puncture and cerebrospinal fluid drainage. Further investigation showed narrowings at the anterior ends of the transverse sinuses, typical of those seen in idiopathic intracranial hypertension and associated with pressure gradients. Stenting of both transverse sinuses brought about a life-changing remission of symptoms with no regression in 2 years of follow-up. This result invites study of an alternative approach to the investigation and management of chronic fatigue.

  9. Intracranial lesions in the acquired immunodeficiency syndrome: radiological (computed tomographic) features

    SciTech Connect

    Elkin, C.M.; Leon, E.; Grenell, S.L.; Leeds, N.E.

    1985-01-18

    Computed tomography (CT) delineates the presence or absence of intracerebral focal lesions in most instances. The presence of contrast enhancement, cerebral atrophy, and an intracranial mass are important in consideration of the differential diagnosis and in establishing the diagnosis. Initially the authors utilized a double dose of contrast medium in all patients after single-dose study, but little additional information was obtained. A second dose of contrast medium is now administered only to evaluate further a suspected lesion. Angiography can confirm the location of the lesion(s) and the cortical veins before biopsy. Of one hundred patients with AIDS examined, 33% had neurological symptoms excluding headache and herpes zoster. All patients with neurological symptoms were studied with noncontrast and contrast CT scanning. Twenty-seven patients in the group had abnormal scans. In 13, the abnormality was limited to a diffuse atrophic appearance, while in 14, focal lesions were identified. Representative cases are discussed and illustrated.

  10. MR imaging features of intracranial primary CNS lymphoma in immune competent patients

    PubMed Central

    2014-01-01

    We aimed to characterize specific MRI findings seen in immune competent patients with intracranial primary CNS lymphoma (PCNSL) and to determine their value in the management of such patients. Pre-treatment MRI examinations of 21 immunocompetent patients with biopsy-proven PCNSL were retrospectively evaluated. T1 and T2 signal characteristics as well as contrast enhancement features are described in all patients. Diffusion, perfusion and proton-MR-spectroscopy features are described in a subset of these patients. In the proper clinical and radiologic setting, suggesting the diagnosis of PCNSL can help institute proper treatment in a timely fashion and avoid unnecessary attempts at surgical resection and the associated morbidity. PMID:25608570

  11. Intracranial vascular malformations: imaging of charged-particle radiosurgery. Part II. Complications

    SciTech Connect

    Marks, M.P.; Delapaz, R.L.; Fabrikant, J.I.; Frankel, K.A.; Phillips, M.H.; Levy, R.P.; Enzmann, D.R.

    1988-08-01

    Seven of 24 patients with intracranial vascular malformations who were treated with helium-ion Bragg-peak radiosurgery had complications of therapy. New symptoms and corresponding radiologic abnormalities developed 4-28 months after therapy. Five patients had similar patterns of white matter changes and mass effect on computed tomographic scans and magnetic resonance images. The abnormalities were centered in the radiation field. Gray matter changes and abnormal enhancement in the thalamus and hypothalamus outside the radiation field developed in one patient. This patient also had vasculopathic changes on angiograms. Rapidly progressive large vessel vasculopathy developed in another patient and caused occlusion of major vessels. Thus, different mechanisms may be involved in the complications of heavy-ion radiosurgery.

  12. Adult Intracranial Gliofibroma : A Case Report and Review of the Literature

    PubMed Central

    Kang, Ho; Se, Young-Bem; Park, Sung-Hye

    2016-01-01

    Gliofibroma is an extremely rare biphasic tumor with an astrocytic and benign mesenchymal component, which commonly occurs within the first two decades of life. The exact biological behavior of the tumor is not fully understood. Therefore, it is not listed as a distinct entity in the current World Health Organization classification of central nervous system tumors. Here, we describe a rare case of gliofibroma, which was located on the medial temporal lobe in a 61-year-old woman. Preoperatively, we misdiagnosed it as a meningioma because it was a well-demarcated and well-enhanced extra-axial mass with calcification and bony destruction. On the histopathological and immunohistochemical examination, the tumor consisted of a mixture of glial tissue and mesenchymal tissue and it was finally diagnosed as a gliofibroma. To our knowledge, this case of intracranial gliofibroma is in the oldest patient ever reported. PMID:27226865

  13. Rings in the solar system

    SciTech Connect

    Pollack, J.B.; Cuzzi, J.N.

    1981-11-01

    Saturn, Jupiter, and Uranus have rings with different structure and composition. The rings consist of tiny masses in independent orbits. Photographs and data obtained by the Voyager project have aided in the understanding of Saturn's rings. Spokes have been found in B ring and boards, knots, and twist in F ring. Particles on the order of a micrometer in size are believed to occur in F, B, and A rings. The dominant component is water ice. The rings of Uranus are narrow and separated by broad empty regions. The technique used to study them has been stellar occulation. Nothing is known of particle size. The dominant component is believed to be silicates rich in compounds that absorb sunlight. Jupiter's rings consist of 3 main parts: a bright ring, a diffuse disk, and a halo. Use of Pioneer 10 data and other techniques have indicated particle sizes on the order of several micrometers and some at least a centimeter in diameter. The architecture of the ring system results from the interplay of a number of forces. These include gravitational forces due to moons outside the rings and moonlets embedded in them, electromagnetic forces due to the planet's rotating magnetic field, and even the gentle forces exerted by the dilute gaseous medium in which the rings rotate. Each of these forces is discussed. Several alternative explanations of how the rings arose are considered. The primary difference in these hypotheses is the account of the relationship between the ring particles of today and the primordial ring material. (SC)

  14. Physics of planetary rings

    NASA Astrophysics Data System (ADS)

    Gorkavyi, N.

    2007-08-01

    It is difficult to enumerate all the surprises presented by the planetary rings. The Saturnian rings are stratified into thousands of ringlets and the Uranian rings are compressed into narrow streams, which for some reason or other differ from circular orbits like the wheel of an old bicycle. The edge of the rings is jagged and the rings themselves are pegged down under the gravitational pressure of the satellites, bending like a ship's wake. There are spiral waves, elliptical rings, strange interlacing of narrow ringlets, and to cap it all one has observed in the Neptunian ring system three dense, bright arcs - like bunches of sausages on a transparent string. For celestial mechanics this is a spectacle as unnatural as a bear's tooth in the necklace of the English queen. In the dynamics of planetary rings the physics of collective interaction was supplemented by taking collisions between particles into account. One was led to study a kinetic equation with a rather complex collision integral - because the collisions are inelastic - which later on made it possible, both by using the Chapman-Enskog method and by using the solution of the kinetic equation for a plasma in a magnetic field, to reduce it to a closed set of (hydrodynamical) moment equations [1]. The hydrodynamical instabilities lead to the growth of short-wavelength waves and large-scale structures of the Saturnian rings [1]. We have shown that the formation of the existing dense Uranian rings is connected with the capture of positively drifting ring particles in inner Lindblad resonances which arrest this drift [1]. After the formation of dense rings at the positions of satellite resonances the collective interaction between resonant particles is amplified and the rings can leave the resonance and drift away from the planet and the parent resonance. We can expect in the C ring an appreciable positive ballistic particle drift caused by the erosion of the B ring by micrometeorites. It is therefore natural

  15. Double Ring Craters

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A faint double ring crater is seen at upper right in this picture of Mercury (FDS 166601) taken one hour and 40 minutes before Mariner 10's second rendezvous with the planet September 21. Located 35 degrees S. Lat. The outer ring is 170 kilometers (10 miles) across. Double ring craters are common features on Mercury. This particular feature and the bright rayed crater to its left were seen from a different viewing angle in pictures taken by Mariner 10 during its first Mercury flyby last March 29.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  16. Oligomeric ferrocene rings

    NASA Astrophysics Data System (ADS)

    Inkpen, Michael S.; Scheerer, Stefan; Linseis, Michael; White, Andrew J. P.; Winter, Rainer F.; Albrecht, Tim; Long, Nicholas J.

    2016-09-01

    Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category—differently sized rings comprising only 1,1‧-disubstituted ferrocene units (cyclo[n], n = 5-7, 9). Due to the close proximity and connectivity of centres (covalent Cp-Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e- waves. Theoretical interrogations into correlations based on ring size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall ring charge and in conjunction with fast intramolecular electron transfer (˜107 s-1), these molecules can be considered as uniformly charged nanorings (diameter ˜1-2 nm).

  17. Oligomeric ferrocene rings

    NASA Astrophysics Data System (ADS)

    Inkpen, Michael S.; Scheerer, Stefan; Linseis, Michael; White, Andrew J. P.; Winter, Rainer F.; Albrecht, Tim; Long, Nicholas J.

    2016-09-01

    Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category—differently sized rings comprising only 1,1‧-disubstituted ferrocene units (cyclo[n], n = 5–7, 9). Due to the close proximity and connectivity of centres (covalent Cp–Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e– waves. Theoretical interrogations into correlations based on ring size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall ring charge and in conjunction with fast intramolecular electron transfer (∼107 s‑1), these molecules can be considered as uniformly charged nanorings (diameter ∼1–2 nm).

  18. Child sex rings.

    PubMed

    Wild, N J; Wynne, J M

    1986-07-19

    Details of 11 child sex rings identified in one working class community were obtained by interviewing investigating police officers and examining health and social services records. The rings contained 14 adult male perpetrators and 175 children aged 6-15 years. Most perpetrators used child ringleaders to recruit victims; others became a "family friend" or obtained a position of authority over children. Secrecy was encouraged and bribery, threats, and peer pressure used to induce participation in sexual activities. Offences reported included fondling, masturbation, pornography, and oral, vaginal, and anal intercourse. Eleven perpetrators were successfully prosecuted; all but one received a sentence of three years or less. Behavioural problems were common among those children who had participated for a long time. Child sex rings are difficult to detect and may be common. Many children are seriously abused as a consequence of them. PMID:3730803

  19. Rings dominate western Gulf

    NASA Astrophysics Data System (ADS)

    Vidal L., Francisco V.; Vidal L., Victor M. V.; Molero, José María Pérez

    Surface and deep circulation of the central and western Gulf of Mexico is controlled by interactions of rings of water pinched from the gulf's Loop Current. The discovery was made by Mexican oceanographers who are preparing a full-color, 8-volume oceanographic atlas of the gulf.Anticyclonic warm-core rings pinch off the Loop Current at a rate of about one to two per year, the scientists of the Grupo de Estudios Oceanográficos of the Instituto de Investigaciones Eléctricas (GEO-IIE) found. The rings migrate west until they collide with the continental shelf break of the western gulf, almost always between 22° and 23°N latitude. On their westward travel they transfer angular momentum and vorticity to the surrounding water, generating cyclonic circulations and vortex pairs that completely dominate the entire surface and deep circulation of the central and western gulf.

  20. A difference ring theory for symbolic summation☆

    PubMed Central

    Schneider, Carsten

    2016-01-01

    A summation framework is developed that enhances Karr's difference field approach. It covers not only indefinite nested sums and products in terms of transcendental extensions, but it can treat, e.g., nested products defined over roots of unity. The theory of the so-called RΠΣ⁎-extensions is supplemented by algorithms that support the construction of such difference rings automatically and that assist in the task to tackle symbolic summation problems. Algorithms are presented that solve parameterized telescoping equations, and more generally parameterized first-order difference equations, in the given difference ring. As a consequence, one obtains algorithms for the summation paradigms of telescoping and Zeilberger's creative telescoping. With this difference ring theory one gets a rigorous summation machinery that has been applied to numerous challenging problems coming, e.g., from combinatorics and particle physics. PMID:26726284

  1. Vascular ring diagnosis following respiratory arrest

    PubMed Central

    Robson, Evie Alexandra; Scott, Alison; Chetcuti, Philip; Crabbe, David

    2014-01-01

    Vascular rings can present with non-specific respiratory and/or oesophageal symptoms. Early diagnosis requires a high index of suspicion. This case report describes an uncommon acute presentation of a vascular ring. We report a thriving 14-month-old child with a long history of recurrent wheeze and ‘noisy breathing’. He presented acutely with food bolus impaction in the oesophagus which led to a respiratory arrest. Oesophagoscopy and bronchoscopy suggested vascular ring anomaly. A contrast-enhanced CT scan demonstrated a right-sided aortic arch with left ligamentum arteriosum encircling the oesophagus and airway. The ligament was ligated and divided. At follow-up 6 months later, the infant had mild persistent stridor but was otherwise well. PMID:24895385

  2. Sliding-Ring Catenanes.

    PubMed

    Fernando, Isurika R; Frasconi, Marco; Wu, Yilei; Liu, Wei-Guang; Wasielewski, Michael R; Goddard, William A; Stoddart, J Fraser

    2016-08-17

    Template-directed protocols provide a routine approach to the synthesis of mechanically interlocked molecules (MIMs), in which the mechanical bonds are stabilized by a wide variety of weak interactions. In this Article, we describe a strategy for the preparation of neutral [2]catenanes with sliding interlocked electron-rich rings, starting from two degenerate donor-acceptor [2]catenanes, consisting of a tetracationic cyclobis(paraquat-p-phenylene) cyclophane (CBPQT(4+)) and crown ethers containing either (i) hydroquinone (HQ) or (ii) 1,5-dioxynaphthalene (DNP) recognition units and carrying out four-electron reductions of the cyclophane components to their neutral forms. The donor-acceptor interactions between the CBPQT(4+) ring and both HQ and DNP units present in the crown ethers that stabilize the [2]catenanes are weakened upon reduction of the cyclophane components to their radical cationic states and are all but absent in their fully reduced states. Characterization in solution performed by UV-vis, EPR, and NMR spectroscopic probes reveals that changes in the redox properties of the [2]catenanes result in a substantial decrease of the energy barriers for the circumrotation and pirouetting motions of the interlocked rings, which glide freely through one another in the neutral states. The solid-state structures of the fully reduced catenanes reveal profound changes in the relative dispositions of the interlocked rings, with the glycol chains of the crown ethers residing in the cavities of the neutral CBPQT(0) rings. Quantum mechanical investigations of the energy levels associated with the four different oxidation states of the catenanes support this interpretation. Catenanes and rotaxanes with sliding rings are expected to display unique properties. PMID:27398609

  3. Idiopathic intracranial hypertension, hormones, and 11β-hydroxysteroid dehydrogenases

    PubMed Central

    Markey, Keira A; Uldall, Maria; Botfield, Hannah; Cato, Liam D; Miah, Mohammed A L; Hassan-Smith, Ghaniah; Jensen, Rigmor H; Gonzalez, Ana M; Sinclair, Alexandra J

    2016-01-01

    Idiopathic intracranial hypertension (IIH) results in raised intracranial pressure (ICP) leading to papilledema, visual dysfunction, and headaches. Obese females of reproductive age are predominantly affected, but the underlying pathological mechanisms behind IIH remain unknown. This review provides an overview of pathogenic factors that could result in IIH with particular focus on hormones and the impact of obesity, including its role in neuroendocrine signaling and driving inflammation. Despite occurring almost exclusively in obese women, there have been a few studies evaluating the mechanisms by which hormones and adipokines exert their effects on ICP regulation in IIH. Research involving 11β-hydroxysteroid dehydrogenase type 1, a modulator of glucocorticoids, suggests a potential role in IIH. Improved understanding of the complex interplay between adipose signaling factors such as adipokines, steroid hormones, and ICP regulation may be key to the understanding and future management of IIH. PMID:27186074

  4. Pathogenesis of optic disc edema in raised intracranial pressure.

    PubMed

    Hayreh, Sohan Singh

    2016-01-01

    Optic disc edema in raised intracranial pressure was first described in 1853. Ever since, there has been a plethora of controversial hypotheses to explain its pathogenesis. I have explored the subject comprehensively by doing basic, experimental and clinical studies. My objective was to investigate the fundamentals of the subject, to test the validity of the previous theories, and finally, based on all these studies, to find a logical explanation for the pathogenesis. My studies included the following issues pertinent to the pathogenesis of optic disc edema in raised intracranial pressure: the anatomy and blood supply of the optic nerve, the roles of the sheath of the optic nerve, of the centripetal flow of fluids along the optic nerve, of compression of the central retinal vein, and of acute intracranial hypertension and its associated effects. I found that, contrary to some previous claims, an acute rise of intracranial pressure was not quickly followed by production of optic disc edema. Then, in rhesus monkeys, I produced experimentally chronic intracranial hypertension by slowly increasing in size space-occupying lesions, in different parts of the brain. Those produced raised cerebrospinal fluid pressure (CSFP) and optic disc edema, identical to those seen in patients with elevated CSFP. Having achieved that, I investigated various aspects of optic disc edema by ophthalmoscopy, stereoscopic color fundus photography and fluorescein fundus angiography, and light microscopic, electron microscopic, horseradish peroxidase and axoplasmic transport studies, and evaluated the effect of opening the sheath of the optic nerve on the optic disc edema. This latter study showed that opening the sheath resulted in resolution of optic disc edema on the side of the sheath fenestration, in spite of high intracranial CSFP, proving that a rise of CSFP in the sheath was the essential pre-requisite for the development of optic disc edema. I also investigated optic disc edema with

  5. Non-thermal irreversible electroporation for deep intracranial disorders.

    PubMed

    Garcia, Paulo A; Neal, Robert E; Rossmeisl, John H; Davalos, Rafael V

    2010-01-01

    Non-thermal irreversible electroporation (N-TIRE) is a new minimally invasive technique to kill undesirable tissue. We build on our previous intracranial studies in order to evaluate the possibility of using N-TIRE for deep intracranial disorders. In this manuscript we describe a minimally invasive computed tomography (CT) guided N-TIRE procedure in white matter. In addition, we report the electric field threshold needed for white matter ablation (630 - 875 V/cm) using four sets of twenty 50 µs pulses at a voltage-to-distance ratio of 1000 V/cm. We also confirm the non-thermal aspect of the technique with real time temperature data measured at the electrode-tissue interface. PMID:21095962

  6. Surgical case of intracranial osteoma arising from the falx

    PubMed Central

    Takeuchi, Satoru; Tanikawa, Rokuya; Tsuboi, Toshiyuki; Noda, Kosumo; Miyata, Shiro; Ota, Nakao; Hamada, Fumihiro; Kamiyama, Hiroyasu

    2016-01-01

    Intracranial osteomas completely unrelated to osseous tissues are extremely rare. In the present study, the case of a 40-year-old female who presented with persistent headache is reported. Computed tomography (CT) and bone window CT revealed an ossified lesion in the frontal area. Fast imaging employing steady-state acquisition (FIESTA)/CT venography fusion imaging demonstrated that the mass was located just below the superior sagittal sinus and cortical veins, and had adhered partially to these veins. Surgery achieved complete tumor removal with preservation of the cortical veins and superior sagittal sinus. The histological examination findings were compatible with osteoma. The present postoperative course was uneventful. The present rare case of intracranial osteoma originating from the falx was successfully treated surgically. Preoperative FIESTA/CT venography fusion imaging was very useful to demonstrate adhesion between the tumor mass and the superior sagittal sinus and cortical veins. PMID:27588144

  7. Thoracolumbar intraspinal tumours presenting features of raised intracranial pressure.

    PubMed Central

    Ridsdale, L; Moseley, I

    1978-01-01

    Five patients are described in whom a benign or malignant thoracolumbar tumour, producing increased level of cerebrospinal fluid protein, was associated with hydrocephalus or papilloedema or both. A review of the clinical and laboratory features in these and 40 published cases underlines the difficulty in explaining the increased intracranial pressure in such patients. Slow absorption of cerebrospinal fluid as a result of the elevated protein levels or recurrent subarachnoid bleeding may play a part. When patients are discovered to have communicating hydrocephalus or a syndrome resemlbing benign intracranial hypertension, the finding of increased cerebrospinal fluid protein or any symptoms or signs relative to the spine should suggest the possibility of an intraspinal tumour. Images PMID:681961

  8. Visual Impairment and Intracranial Hypertension: An Emerging Spaceflight Risk

    NASA Technical Reports Server (NTRS)

    Taddeo, Terrance A.

    2010-01-01

    During recent long duration missions to the International Space Station (ISS) crewmembers have reported changes in visual acuity or visual field defects. Exams in the postflight period revealed changes to the visual system and elevated intracranial pressures. As a result, NASA Space Medicine has added a number of tests to be performed in the preflight, inflight and postflight periods for ISS and shuttle missions with the goal of determining the processes at work and any potential mitigation strategies. This discussion will acquaint you with the changes that NASA has made to its medical requirements in order to address the microgravity induced intracranial hypertension and associated visual changes. Key personnel have been assembled to provide you information on this topic. Educational Objectives: Provide an overview of the current Medical Operations requirements and the mitigation steps taken to operationally address the issue.

  9. Multiple Intracranial Aneurysms Associated with Behçet's Disease

    PubMed Central

    Ha, Sangwoo; Kim, Jaeho; Kim, Chong-gue

    2016-01-01

    Behçet's disease is an inflammatory disorder involving multiple organs. Its cause is still unknown, but vasculitis is the major pathologic characteristic. The common vascular lesions associated with Behçet's disease are aneurysm formation, arterial or venous occlusive diseases, and varices. Arterial aneurysms mostly occur in large arteries. Intracranial aneurysms hardly occur with Behçet's disease. We would like to present a 41-year-old female patient with Behçet's disease who showed symptoms of severe headache due to subarachnoid hemorrhage. Brain computed tomography revealed multiple aneurysms. We also present a literature review of intracranial arterial aneurysms associated with Behçet's disease. PMID:27114964

  10. Primary Intracranial Myoepithelial Neoplasm: A Potential Mimic of Meningioma.

    PubMed

    Choy, Bonnie; Pytel, Peter

    2016-05-01

    Myoepithelial neoplasms were originally described in the salivary glands but their spectrum has been expanding with reports in other locations, including soft tissue. Intracranial cases are exceptionally rare outside the sellar region where they are assumed to be arising from Rathke pouch rests. Two cases of pediatric intracranial myoepithelial neoplasm in the interhemispheric fissure and the right cerebral hemisphere are reported here. Imaging studies suggest that the second case was associated with cerebrospinal fluid dissemination. Both cases showed typical variation in morphology and immunophenotype between more epithelioid and more mesenchymal features. The differential diagnosis at this particular anatomic location includes meningioma, which can show some overlap in immunophenotype since both tumors express EMA as well as GLUT1. One case was positive for EWSR1 rearrangement by fluorescence in situ hybridization. One patient is disease free at last follow-up while the other succumbed to the disease within days illustrating the clinical spectrum of these tumors.

  11. Right cardiac intracavitary metastases from a primary intracranial myxofibrosarcoma.

    PubMed

    Costa, Diogo Alpuim; Barata, Pedro; Gouveia, Emanuel; Mafra, Manuela

    2016-01-01

    Primary intracranial myxofibrosarcoma is exceedingly rare, with less than 10 cases published. We present a case of a 23-year-old man with previous history of a primary low grade myxofibrosarcoma of the left parietal-occipital convexity resected in March 1999. He subsequently underwent several interventions for multiple local recurrent disease until March 2004. At that time, complete remission was documented. About 8 years later, in February 2012, the patient was admitted to the emergency room with refractory acute pulmonary oedema. On work up, sustained monomorphic ventricular tachycardia and hyperechoic myocardial mass with invasion of the right ventricular cavity were detected. Electrical cardioversion was unsuccessful and irreversible cardiac arrest followed. The autopsy confirmed multiple bilateral lung metastases, malignant pulmonary embolism and myocardial invasion by the primary tumour, with intracavitary cardiac thrombosis and absence of intracranial disease. To the best of our knowledge, this is the first report of extracranial metastases of this neoplasm. PMID:27013654

  12. Unsteady velocity measurements in a realistic intracranial aneurysm model

    NASA Astrophysics Data System (ADS)

    Ugron, Ádám; Farinas, Marie-Isabelle; Kiss, László; Paál, György

    2012-01-01

    The initiation, growth and rupture of intracranial aneurysms are intensively studied by computational fluid dynamics. To gain confidence in the results of numerical simulations, validation of the results is necessary. To this end the unsteady flow was measured in a silicone phantom of a realistic intracranial aneurysm. A flow circuit was built with a novel unsteady flow rate generating method, used to model the idealised shape of the heartbeat. This allowed the measurement of the complex three-dimensional velocity distribution by means of laser-optical methods such as laser doppler anemometry (LDA) and particle image velocimetry (PIV). The PIV measurements, available with high temporal and spatial distribution, were found to have good agreement with the control LDA measurements. Furthermore, excellent agreement was found with the numerical results.

  13. [Measuring intracranial pressure with a fontanelle palpation transducer (author's transl)].

    PubMed

    Hirsch, J F; Lacombe, J; Pierre-Kahn, A; Renier, D

    1978-01-01

    The accuracy and reliability of a non-invasive method for the measurement of intracranial pressure through the fontanelle without puncture was tested during 12 or even 24 hours recordings. Wealthall and Smallwood modified aplanation transducer was first used. A metal frame had to be developed in order to secure the transducer rigidly over the fontanelle so that the recording could take place with the infant in any position and completely free of its movements. Simultaneous recordings of extradural or intraventricular pressure have shown the measurements were accurate to about 1 or 2 cm H2O in a neurosurgical environnement (i.e large fontanelles with pressure over 10 cm H2O). For smaller fontanelles or low or even negative intracranial pressure, a smaller transducer seems to be needed. The preliminary test of a plane strain gauge transducer that partially fills this need is shown.

  14. Controversies in epidemiology of intracranial aneurysms and SAH.

    PubMed

    Korja, Miikka; Kaprio, Jaakko

    2016-01-01

    Rupture of an intracranial aneurysm is the most common cause of subarachnoid haemorrhage (SAH), which is a life-threatening acute cerebrovascular event that typically affects working-age people. The exact prevalence of unruptured intracranial aneurysms (UIAs) is unknown, but at least one in 20 to 30 adults is likely to carry an asymptomatic UIA. Approximately one quarter of these UIAs rupture in a lifetime. Complex methodological challenges in conducting studies of epidemiology and risk factors for UIAs and SAH might have led to conclusions being drawn on the basis of epidemiological data of variable quality. We believe that, as a result, misconceptions about UIAs and SAH may have arisen. In this Perspectives article, we discuss three possible misconceptions about the epidemiology of UIAs and SAH, and suggest how the quality of future research could be improved. PMID:26670298

  15. Ring laser gyroscope anode

    SciTech Connect

    Ljung, B.H.

    1981-03-17

    An anode for a ring laser gyroscope which provides improved current stability in the glow discharge path is disclosed. The anode of this invention permits operation at lower currents thereby allowing a reduction of heat dissipation in the ring laser gyroscope. The anode of one embodiment of this invention is characterized by a thumbtack appearance with a spherical end where the normal sharp end of the thumbtack would be located. The stem of the anode extends from the outside of the gyroscope structure to the interior of the structure such that the spherical end is substantially adjacent to the laser beam.

  16. The covariant chiral ring

    NASA Astrophysics Data System (ADS)

    Bourget, Antoine; Troost, Jan

    2016-03-01

    We construct a covariant generating function for the spectrum of chiral primaries of symmetric orbifold conformal field theories with N = (4 , 4) supersymmetry in two dimensions. For seed target spaces K3 and T 4, the generating functions capture the SO(21) and SO(5) representation theoretic content of the chiral ring respectively. Via string dualities, we relate the transformation properties of the chiral ring under these isometries of the moduli space to the Lorentz covariance of perturbative string partition functions in flat space.

  17. GUARD RING SEMICONDUCTOR JUNCTION

    DOEpatents

    Goulding, F.S.; Hansen, W.L.

    1963-12-01

    A semiconductor diode having a very low noise characteristic when used under reverse bias is described. Surface leakage currents, which in conventional diodes greatly contribute to noise, are prevented from mixing with the desired signal currents. A p-n junction is formed with a thin layer of heavily doped semiconductor material disposed on a lightly doped, physically thick base material. An annular groove cuts through the thin layer and into the base for a short distance, dividing the thin layer into a peripheral guard ring that encircles the central region. Noise signal currents are shunted through the guard ring, leaving the central region free from such currents. (AEC)

  18. Unidirectional ring lasers

    DOEpatents

    Hohimer, John P.; Craft, David C.

    1994-01-01

    Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction.

  19. Unidirectional ring lasers

    DOEpatents

    Hohimer, J.P.; Craft, D.C.

    1994-09-20

    Unidirectional ring lasers formed by integrating nonreciprocal optical elements into the resonant ring cavity is disclosed. These optical elements either attenuate light traveling in a nonpreferred direction or amplify light traveling in a preferred direction. In one preferred embodiment the resonant cavity takes the form of a circle with an S-shaped crossover waveguide connected to two points on the interior of the cavity such that light traveling in a nonpreferred direction is diverted from the cavity into the crossover waveguide and reinjected out of the other end of the crossover waveguide into the cavity as light traveling in the preferred direction. 21 figs.

  20. Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry

    2004-01-01

    The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.

  1. Esthesioneuroblastoma with intracranial extension: A non-surgical approach.

    PubMed

    Thomas, Sarah Boby; Balasubramaniam, Deepak; Hiran, K R; Dinesh, M; Pavithran, K

    2016-01-01

    Esthesioneuroblastoma is a rare tumor arising from the olfactory mucosa of upper respiratory tract. The primary modality of treatment has been surgery with craniofacial resection followed by post-operative radiotherapy. There are only a few reported cases of non-surgical approaches. We report a case of esthesioneuroblastoma with intracranial extension treated with Vincristine, Adriamycin, Cyclophosphamide, Ifosfamide, Etoposide protocol followed by radiation with 5 years of follow-up. This is the first reported case using this chemotherapy schedule. PMID:27366272

  2. Esthesioneuroblastoma with intracranial extension: A non-surgical approach

    PubMed Central

    Thomas, Sarah Boby; Balasubramaniam, Deepak; Hiran, K. R.; Dinesh, M.; Pavithran, K.

    2016-01-01

    Esthesioneuroblastoma is a rare tumor arising from the olfactory mucosa of upper respiratory tract. The primary modality of treatment has been surgery with craniofacial resection followed by post-operative radiotherapy. There are only a few reported cases of non-surgical approaches. We report a case of esthesioneuroblastoma with intracranial extension treated with Vincristine, Adriamycin, Cyclophosphamide, Ifosfamide, Etoposide protocol followed by radiation with 5 years of follow-up. This is the first reported case using this chemotherapy schedule. PMID:27366272

  3. Large Intracranial Aneurysm after Transsphenoidal Surgery for Pituitary Macroadenoma

    PubMed Central

    Yoon, Kyeong-Wook; Cho, Chun-Sung

    2014-01-01

    Uncontrolled cerebrospinal fluid (CSF) leakage after transsphenoidal surgery (TSS) for pituitary adenoma can lead to meningitis. Intracranial mycotic pseudoaneurysm is a rare complication in central nervous system infection. Large single pseudoaneurysm is more uncommon. Most mycotic aneurysms occur due to endocarditis. The present patient had no heart problem and was infected by CSF leakage after transsphenoidal surgery. We present a case of large ruptured mycotic pseudoaneurysm as a complication of cerebral infection after TSS for pituitary macroadenoma. PMID:24851153

  4. Late complication after tropic storm accident: subcutaneous and intracranial actinomycetoma.

    PubMed

    Verma, Shyam B; Nayak, Suresh; Pasale, Ravindra K; Kittner, Thomas; Wollina, Uwe

    2008-12-01

    We report a 53-year-old farmer who developed subcutaneous and cerebral masses 24 years after penetrating trauma during a tropic storm. Computed tomography scans, magnetic resonance imaging and histopathology disclosed actinomycetoma, a disease that rarely develops after trauma and is only occasionally seen with intracranial manifestation. Clinically, the cutaneous manifestation resembled acne keloidalis nuchae or dissecting folliculitis of the scalp. He was treated by neurosurgery and antibiosis.

  5. Prediscovery evidence of planetary rings

    NASA Technical Reports Server (NTRS)

    Mclaughlin, W. I.

    1980-01-01

    The discoveries of the Uranian and Jovian ring systems were surprising events to most of the scientific community. However, as far back as 1787 reports of observations of rings about a planet other than Saturn were made; Herschel, the discoverer of Uranus, thought he had detected rings about that planet on several occasions. Although Herschel's observations were almost certainly due to defects in the optical system of his telescope, several valid observations and predictions have been made in the last two hundred years. This paper focuses on such prediscovery evidence for the Uranian and Jovian rings and for the newly designated F ring of Saturn. Some new work of the author on the structure of the Saturnian rings is included which is relevant to the F ring. The prospects for rings about Neptune and Pluto and a ring close to the Sun are also reviewed. The relevance of the prediscovery evidence to aspects of scientific methodology is discussed.

  6. Ring Wing for an underwater missile

    NASA Astrophysics Data System (ADS)

    August, Henry; Carapezza, Edward

    Hughes Aircraft has performed exploratory wind tunnel studies of compressed carriage missile designs having extendable Ring Wing and wrap-around tail control surfaces. These force and moment data indicate that significant improvements in a missile's lift and aerodynamic efficiency can be realized. Low speed test results of these data were used to estimate potential underwater improved hydrodynamic characteristics that a Ring Wing and wrap-around tails can bring to an advanced torpedo design. Estimates of improved underwater flight performance of a heavyweight torpedo (4000 lbs.) having an extendable Ring Wing and wrap-around tails were made. The compressed volume design of this underwater missile is consistent with tube-launch constraints and techniques. Study results of this novel Ring Wing torpedo design include extended flight performance in range and endurance due to lowered speeds capable of sustaining underwater level flight. Correspondingly, reduced radiated noise for enhanced stealth qualities is projected. At high speeds, greater maneuverability and aimpoint selection can be realized by a Ring Wing underwater missile.

  7. Adhesion rings surround invadopodia and promote maturation

    PubMed Central

    Branch, Kevin M.; Hoshino, Daisuke; Weaver, Alissa M.

    2012-01-01

    Summary Invasion and metastasis are aggressive cancer phenotypes that are highly related to the ability of cancer cells to degrade extracellular matrix (ECM). At the cellular level, specialized actin-rich structures called invadopodia mediate focal matrix degradation by serving as exocytic sites for ECM-degrading proteinases. Adhesion signaling is likely to be a critical regulatory input to invadopodia, but the mechanism and location of such adhesion signaling events are poorly understood. Here, we report that adhesion rings surround invadopodia shortly after formation and correlate strongly with invadopodium activity on a cell-by-cell basis. By contrast, there was little correlation of focal adhesion number or size with cellular invadopodium activity. Prevention of adhesion ring formation by inhibition of RGD-binding integrins or knockdown (KD) of integrin-linked kinase (ILK) reduced the number of ECM-degrading invadopodia and reduced recruitment of IQGAP to invadopodium actin puncta. Furthermore, live cell imaging revealed that the rate of extracellular MT1-MMP accumulation at invadopodia was greatly reduced in both integrin-inhibited and ILK-KD cells. Conversely, KD of MT1-MMP reduced invadopodium activity and dynamics but not the number of adhesion-ringed invadopodia. These results suggest a model in which adhesion rings are recruited to invadopodia shortly after formation and promote invadopodium maturation by enhancing proteinase secretion. Since adhesion rings are a defining characteristic of podosomes, similar structures formed by normal cells, our data also suggest further similarities between invadopodia and podosomes. PMID:23213464

  8. Age-dependence of intracranial viscoelastic properties in living rats.

    PubMed

    Shulyakov, Alexander V; Cenkowski, Stefan S; Buist, Richard J; Del Bigio, Marc R

    2011-04-01

    To explore the effect of maturation on intracranial mechanical properties, viscoelastic parameters were determined in 44 live rats at ages 1-2, 10-12, 21, 56-70, and 180 days using instrumented indentation. With the dura mater intact, the apparent modulus of elasticity, the indentation modulus, and viscous behavior were measured in vivo, as well as 1 h after death. In a separate group of 25 rats, brain water, and protein content were determined. A significant increase of the elastic and indentation moduli beginning at 10-12 days after birth and continuing to 180 days was observed. The creep behavior decreased in the postnatal period and stabilized at 21 days. Changes in intracranial biomechanical properties corresponded to a gradual decrease of brain water, and an increase in total protein content, including glial fibrillary acidic protein, myelin basic protein, and neurofilament light chain. Elastic properties were not significantly different comparing the live and dead states. However, there were significant postmortem changes in viscous behavior. Viscoelastic properties of living rat intracranial contents are shown to be age dependent, reflecting the physical and biochemical changes during postnatal development. This may be important for understanding why young and mature brains respond differently in situations of brain trauma and hydrocephalus.

  9. Visuoperceptual sequelae in children with hemophilia and intracranial hemorrhage

    PubMed Central

    Matute, Esmeralda; O’Callaghan, Erin T.; Murray, Joan; Tlacuilo-Parra, Alberto

    2015-01-01

    Background The goal of this study was to examine the impact of focal brain injuries on the outcomes of visual perception and visuospatial abilities in Mexican children with hemophilia who have experienced intracranial hemorrhages. Methods We assessed ten boys who had hemophilia with intracranial hemorrhage (HIC), six boys who had hemophilia without intracranial hemorrhage (HH), and ten boys without hemophilia (CTL). The Verbal (VIQ), Performance IQs (PIQ), and Full Scale IQs (FSIQ) from the Wechsler Intelligence Scale for Children—Mexican Revision, Visual Perception, and Visuospatial Abilities domains, which are from a neuropsychological assessment battery for Spanish-speaking children (ENI), were employed for our analysis. Results The results showed that the HIC group performed in the low-average range on the PIQ and FSIQ, which was lower than the HH group. The HIC group showed low performance on visual perception tests, such as line orientation, fragmented objects, and overlapping figures, compared with their matched controls. Conclusions The results suggest that it is not the ability to recognize objects that is impaired in the HIC group, but the ability to identify objects under less favorable conditions. Our findings may have therapeutic and rehabilitative implications for the management of children with hemophilia and early focal brain lesions. PMID:26835360

  10. Furosemide lowers intracranial pressure by inhibiting CSF production.

    PubMed

    Lorenzo, A V; Hornig, G; Zavala, L M; Boss, V; Welch, K

    1986-12-01

    Furosemide administration effectively lowers intracranial pressure in newborn preterm and term rabbit pups. This effect may be due to the diuretic action of the drug, its ability to inhibit cerebrospinal fluid production or to a combination of both. To test these possibilities newborn rabbits were either injected with furosemide and left unmolested for 6 hours, or anaesthetized and subjected to ventriculocisternal perfusions. During the 6 hour postnatal period the decrease in body weight was 8 times greater in furosemide than in saline treated pups. However, no difference was noted between the average brain weights of these two groups. Secondary effects of the diuretic were noted in blood (12.5% increase in the haematocrit over control value) and in muscle in which tissue water content and NA+ concentration were decreased while K+ concentration was increased. The fact that these parameters remained unchanged in brain suggests that the lowering of intracranial pressure was not attributable to the secondary effects of the diuretic agent. However, the marked reduction in cerebrospinal production noted following furosemide administration indicates that in newborn rabbits this may represent the primary mechanism by which furosemide lowers intracranial pressure.

  11. Noninvasive measurement of pulsatile intracranial pressure using ultrasound

    NASA Technical Reports Server (NTRS)

    Ueno, T.; Ballard, R. E.; Shuer, L. M.; Cantrell, J. H.; Yost, W. T.; Hargens, A. R.

    1998-01-01

    The present study was designed to validate our noninvasive ultrasonic technique (pulse phase locked loop: PPLL) for measuring intracranial pressure (ICP) waveforms. The technique is based upon detecting skull movements which are known to occur in conjunction with altered intracranial pressure. In bench model studies, PPLL output was highly correlated with changes in the distance between a transducer and a reflecting target (R2 = 0.977). In cadaver studies, transcranial distance was measured while pulsations of ICP (amplitudes of zero to 10 mmHg) were generated by rhythmic injections of saline. Frequency analyses (fast Fourier transformation) clearly demonstrate the correspondence between the PPLL output and ICP pulse cycles. Although theoretically there is a slight possibility that changes in the PPLL output are caused by changes in the ultrasonic velocity of brain tissue, the decreased amplitudes of the PPLL output as the external compression of the head was increased indicates that the PPLL output represents substantial skull movement associated with altered ICP. In conclusion, the ultrasound device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. Our technique makes it possible to analyze ICP waveforms noninvasively and will be helpful for understanding intracranial compliance and cerebrovascular circulation.

  12. Spontaneous intracranial hypotension: Targeted or blind blood patch.

    PubMed

    Smith, Kyle A

    2016-03-01

    The aim of this review is to determine the efficacy and optimal strategy for epidural blood patch placement in the treatment of spontaneous intracranial hypotension. We present a 37-year-old man who developed a 4 week duration postural headache without sustaining significant trauma. The diagnosis of spontaneous intracranial hypotension with associated subdural hygromas was confirmed with lumbar puncture and radiologic imaging. Spontaneous intracranial hypotension is generally due to cerebrospinal fluid leak from the thecal sac or nerve root sleeves, although the cause of leakage is unknown. In our patient, the site of leakage was identified at cervical C1-C2 level in the spine on myelography. Conservative management with repeated epidural blood patches was successful in symptom relief and complete resolution of cerebrospinal fluid leak and subdural hygromas. We reviewed the literature for efficacy of blood patches delivered directly to the site of leakage (targeted) or to the lumbar or thoracic spine away from the site of leakage or where the site cannot be determined (blind). No clear evidence exists on comparative efficacy due to paucity of randomized trials. However, epidural blood patches in general result in positive outcomes with overall efficacy near 90%. Some trials have suggested greater efficacy for targeted rather than blind epidural blood patches, but randomized studies and long-term prognosis remain to be evaluated. PMID:26461907

  13. Flow diversion for complex intracranial aneurysms in young children.

    PubMed

    Navarro, Ramon; Brown, Benjamin L; Beier, Alexandra; Ranalli, Nathan; Aldana, Philipp; Hanel, Ricardo A

    2015-03-01

    Pediatric intracranial aneurysms are exceedingly rare and account for less than 5% of all intracranial aneurysms. Open surgery to treat such aneurysms has been shown to be more durable than endovascular techniques, and durability of treatment is particularly important in the pediatric population. Over the past 2 decades, however, a marked shift in aneurysm treatment from open surgery toward endovascular procedures has occurred for adults. The authors describe their early experience in treating 3 unruptured pediatric brain aneurysms using the Pipeline embolization device (PED). The first patient, a girl with Majewski osteodysplastic primordial dwarfism Type II who was harboring multiple intracranial aneurysms, underwent two flow diversion procedures for a vertebrobasilar aneurysm and a supraclinoid internal carotid artery aneurysm. The second patient underwent PED placement on a previously coiled but enlarging posterior communicating artery aneurysm. All procedures were uneventful, with no postsurgical complications, and led to complete angiographic obliteration of the aneurysms. To the authors' knowledge, this is the first series of flow diversion procedures in children reported in the medical literature. While flow diversion is a new and relatively untested technology in children, outcomes in adults have been promising. For challenging lesions in the pediatric population, flow diversion may have a valuable role as a well-tolerated, safe treatment with durable results. Many issues remain to be addressed, such as the durability of flow diverters over a very long follow-up and vessel response to growth in the presence of an endoluminal device.

  14. Treatment of ruptured intracranial dissecting aneurysms in Hong Kong

    PubMed Central

    Wong, George Kwok Chu; Tang, Hoi Bun; Poon, Wai Sang; Yu, Simon Chun Ho

    2010-01-01

    Background: Data suggests that hemorrhagic presentations occur in 20% of internal carotid artery dissections and 50% of vertebral artery dissections. A Finnish study has reported favorable outcomes in only 32% of patients. We aimed to review the epidemiology and management outcomes in a Chinese population. Methods: We reviewed the aneurysmal subarachnoid hemorrhage registry of patients who presented with intracranial dissecting aneurysms at a neurosurgical center in Hong Kong over a five-year period. Results: A total of 23 patients with intracranial dissecting aneurysms were identified, accounting for 8% of all spontaneous subarachnoid hemorrhage patients. Forty-eight percent of the patients identified were treated by main trunk occlusion and 39% were treated by embolization or stent-assisted embolization or stent alone. Thirteen percent were managed by craniotomy and trapping or wrapping. Favorable outcomes at six months were achieved in 67%. Conclusions: Patients with intracranial dissecting aneurysms account for a significant proportion of the cases of spontaneous subarachnoid hemorrhage in our population. Carefully selected endovascular and microsurgical treatments can lead to management outcomes similar to patients with saccular aneurysms. PMID:21206536

  15. Flow diversion for complex intracranial aneurysms in young children.

    PubMed

    Navarro, Ramon; Brown, Benjamin L; Beier, Alexandra; Ranalli, Nathan; Aldana, Philipp; Hanel, Ricardo A

    2015-03-01

    Pediatric intracranial aneurysms are exceedingly rare and account for less than 5% of all intracranial aneurysms. Open surgery to treat such aneurysms has been shown to be more durable than endovascular techniques, and durability of treatment is particularly important in the pediatric population. Over the past 2 decades, however, a marked shift in aneurysm treatment from open surgery toward endovascular procedures has occurred for adults. The authors describe their early experience in treating 3 unruptured pediatric brain aneurysms using the Pipeline embolization device (PED). The first patient, a girl with Majewski osteodysplastic primordial dwarfism Type II who was harboring multiple intracranial aneurysms, underwent two flow diversion procedures for a vertebrobasilar aneurysm and a supraclinoid internal carotid artery aneurysm. The second patient underwent PED placement on a previously coiled but enlarging posterior communicating artery aneurysm. All procedures were uneventful, with no postsurgical complications, and led to complete angiographic obliteration of the aneurysms. To the authors' knowledge, this is the first series of flow diversion procedures in children reported in the medical literature. While flow diversion is a new and relatively untested technology in children, outcomes in adults have been promising. For challenging lesions in the pediatric population, flow diversion may have a valuable role as a well-tolerated, safe treatment with durable results. Many issues remain to be addressed, such as the durability of flow diverters over a very long follow-up and vessel response to growth in the presence of an endoluminal device. PMID:25555114

  16. 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

  17. Recanalization Results After Intracranial Stenting of Atherosclerotic Stenoses

    SciTech Connect

    Blasel, Stella Yuekzek, Zeynep; Kurre, Wiebke; Berkefeld, Joachim; Neumann-Haefelin, Tobias; Hattingen, Elke; Mesnil de Rochemont, Richard du

    2010-10-15

    The purpose of this investigation was to provide a detailed description of the angiographic results after stenting of high-grade intracranial stenosis using balloon-expandable stents. Forty consecutive patients with symptomatic atherosclerotic intracranial stenosis >50% received endovascular treatment by placement of balloon-expandable stents using the concept of slight underdilation and strict avoidance of overdilation. Intra-arterial digital subtraction angiography images before and after stenting in the same projection were reviewed for pre- and post-therapeutic measurement of the degree of stenosis and evaluation of morphologic criteria like plaque coverage, stent apposition, patency of side branches, and signs of dissection or vasospasm. Stenting decreased the mean percentage stenosis from 76.2 (WASID criteria) to 20.8%. Residual stenosis ranged from 0 to 55% with residual stenosis >50% in two of 40 cases. Technical success rate was 95%. There were no major vessel complications, but minor abnormalities like incomplete stent apposition (8/40) or plaque coverage (7/40), incomplete filling of side branches (13/40), and minor dissections after stenting (2/40) were seen. One case with incomplete stent apposition and two cases with side branch compromise were associated with clinical symptoms. In conclusion, intracranial stenting with slight underdilation avoided major vessel complication and created reliable luminal gain. Suboptimal recanalization results were frequently detected and may be the source of neurological complications in individual cases.

  18. Low-dose prophylactic craniospinal radiotherapy for intracranial germinoma

    SciTech Connect

    Schoenfeld, Gordon O.; Amdur, Robert J. . E-mail: amdurrj@ufl.edu; Schmalfuss, Ilona M.; Morris, Christopher G.; Keole, Sameer R.; Mendenhall, William M.; Marcus, Robert B.

    2006-06-01

    Purpose: To report outcomes of patients with localized intracranial germinoma treated with low-dose craniospinal irradiation (CSI) followed by a boost to the ventricular system and primary site. Methods and Materials: Thirty-one patients had pathologically confirmed intracranial germinoma and no spine metastases. Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction. Our neuroradiologist recorded three-dimensional tumor size on magnetic resonance images before, during, and after radiotherapy. Results: With a median follow-up of 7.0 years, 29 of 31 patients (94%) are disease free. One failure had nongerminomatous histology; the initial diagnosis was a sampling error. Of 3 patients who did not receive CSI, 1 died. No patient developed myelopathy, visual deficits, dementia, or skeletal growth problems. In locally controlled patients, tumor response according to magnetic resonance scan was nearly complete within 6 months after radiotherapy. Conclusions: Radiotherapy alone with low-dose prophylactic CSI cures almost all patients with localized intracranial germinoma. Complications are rare when the daily dose of radiotherapy is limited to 1.5 Gy and the total CSI dose to 21 Gy. Patients without a near-complete response to radiotherapy should undergo resection to rule out a nongerminomatous element.

  19. Performing behavioral tasks in subjects with intracranial electrodes.

    PubMed

    Johnson, Matthew A; Thompson, Susan; Gonzalez-Martinez, Jorge; Park, Hyun-Joo; Bulacio, Juan; Najm, Imad; Kahn, Kevin; Kerr, Matthew; Sarma, Sridevi V; Gale, John T

    2014-01-01

    Patients having stereo-electroencephalography (SEEG) electrode, subdural grid or depth electrode implants have a multitude of electrodes implanted in different areas of their brain for the localization of their seizure focus and eloquent areas. After implantation, the patient must remain in the hospital until the pathological area of brain is found and possibly resected. During this time, these patients offer a unique opportunity to the research community because any number of behavioral paradigms can be performed to uncover the neural correlates that guide behavior. Here we present a method for recording brain activity from intracranial implants as subjects perform a behavioral task designed to assess decision-making and reward encoding. All electrophysiological data from the intracranial electrodes are recorded during the behavioral task, allowing for the examination of the many brain areas involved in a single function at time scales relevant to behavior. Moreover, and unlike animal studies, human patients can learn a wide variety of behavioral tasks quickly, allowing for the ability to perform more than one task in the same subject or for performing controls. Despite the many advantages of this technique for understanding human brain function, there are also methodological limitations that we discuss, including environmental factors, analgesic effects, time constraints and recordings from diseased tissue. This method may be easily implemented by any institution that performs intracranial assessments; providing the opportunity to directly examine human brain function during behavior. PMID:25349952

  20. Trends in cognitive dysfunction following surgery for intracranial tumors

    PubMed Central

    Dhandapani, Manju; Gupta, Sandhya; Mohanty, Manju; Gupta, Sunil Kumar; Dhandapani, Sivashanmugam

    2016-01-01

    Background: This study was conducted to prospectively assess the cognitive function of patients with intracranial tumors. Methods: The cognitive status of patients with intracranial tumors were prospectively studied before surgery, and later at 1 and 6 months following surgery, on purposive sampling, using validated post graduate institute (PGI) battery for brain dysfunction (score 0–30) with a higher dysfunction rating score indicating poor cognitive status. Results: Out of 23 patients enrolled, 20 could complete the study. They had substantial cognitive dysfunction before surgery (score 17.1 ± 9.4). Though there was no significant improvement (16.9 ± 9.0) at 1 month, the score improved significantly (10.3 ± 9.2) at 6 months following surgery (P = 0.008). The improvement was relatively subdued in intra-axial, malignant, and radiated tumors. Overall, there was a significant improvement in mental balance (P = 0.048), verbal retention of dissimilar pairs (P = 0.01), and recognition (P = 0.01), while dysfunction persisted in the domains of memory, verbal retention to similar pairs, and visual retention. Conclusion: Patients with intracranial tumors have substantial cognitive dysfunction, which tend to show significant improvement beyond 6 months following surgery, especially among tumors, which were extra-axial, benign, and nonirradiated. PMID:27114854

  1. Idiopathic intracranial hypertension in the Middle East: A growing concern

    PubMed Central

    Almarzouqi, Sumayya J.; Morgan, Michael L.; Lee, Andrew G.

    2014-01-01

    Idiopathic Intracranial Hypertension (IIH) is a disorder of increased intracranial pressure without any identifiable etiology. It is defined by elevated intracranial pressure (ICP) with normal neuroimaging and normal cerebrospinal fluid (CSF) contents. IIH typically affects young obese women and produces symptoms and signs related to high ICP. Headache and blurred vision are the most common symptoms, and papilledema is the major clinical sign. In this review we examine the epidemiology and demographic features of IIH in Middle Eastern countries and compare and contrast them with the published IIH literature from Western countries. The incidence of IIH in several Middle East countries has been estimated at 2.02–2.2/100,000 in the general population, which is higher than the Western rate. Obesity is a major risk factor globally and it is associated with an increased risk of severe vision loss due to IIH. There has been an increase in obesity prevalence in the Middle East countries mainly affecting the Gulf Council Countries (GCC), which parallels increased industrial development. This rise may be contributing to the increasing incidence of IIH in these countries. Other risk factors may also be contributing to IIH in Middle East countries and the differences and similarities to Western IIH merit further study. PMID:25859136

  2. Microfabricated optofluidic ring resonator structures

    PubMed Central

    Scholten, Kee; Fan, Xudong; Zellers, Edward. T.

    2011-01-01

    We describe the fabrication and preliminary optical characterization of rugged, Si-micromachined optofluidic ring resonator (μOFRR) structures consisting of thin-walled SiOx cylinders with expanded midsections designed to enhance the three-dimensional confinement of whispering gallery modes (WGMs). These μOFRR structures were grown thermally at wafer scale on the interior of Si molds defined by deep-reactive-ion etching and pre-treated to reduce surface roughness. Devices 85-μm tall with 2-μm thick walls and inner diameters ranging from 50 to 200 μm supported pure-mode WGMs with Q-factors >104 near 985 nm. Advantages for eventual vapor detection in gas chromatographic microsystems are highlighted. PMID:22053110

  3. Formation dynamics in geostationary ring

    NASA Astrophysics Data System (ADS)

    Spiridonova, Sofya

    2016-08-01

    A relative motion model for a satellite formation composed of two Earth-orbiting spacecraft located in the geostationary ring is developed taking into account major gravitational and non-gravitational forces. A previously existing model featuring perturbation due to J_2 is enhanced by the perturbations due to solar radiation pressure arising from unequal area-to-mass ratios, as well as the secular and long-periodic gravitational perturbations due to the Sun and the Moon. The extended relative motion model is validated using several typical formation geometries against a reference generated by numerical integration of the absolute orbits of the two spacecraft. The results of this work can find application in future on-orbit servicing and formation flying missions in near-geostationary orbit.

  4. Flushing Ring for EDM

    NASA Technical Reports Server (NTRS)

    Earwood, L.

    1985-01-01

    Removing debris more quickly lowers cutting time. Operation, cutting oil and pressurized air supplied to ring placed around workpiece. Air forces oil through small holes and agitates oil as it flows over workpiece. High flow rate and agitation dislodge and remove debris. Electrical discharge removes material from workpiece faster.

  5. Ring of Stellar Death

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image from NASA's Spitzer Space Telescope shows a dying star (center) surrounded by a cloud of glowing gas and dust. Thanks to Spitzer's dust-piercing infrared eyes, the new image also highlights a never-before-seen feature -- a giant ring of material (red) slightly offset from the cloud's core. This clumpy ring consists of material that was expelled from the aging star.

    The star and its cloud halo constitute a 'planetary nebula' called NGC 246. When a star like our own Sun begins to run out of fuel, its core shrinks and heats up, boiling off the star's outer layers. Leftover material shoots outward, expanding in shells around the star. This ejected material is then bombarded with ultraviolet light from the central star's fiery surface, producing huge, glowing clouds -- planetary nebulas -- that look like giant jellyfish in space.

    In this image, the expelled gases appear green, and the ring of expelled material appears red. Astronomers believe the ring is likely made of hydrogen molecules that were ejected from the star in the form of atoms, then cooled to make hydrogen pairs. The new data will help explain how planetary nebulas take shape, and how they nourish future generations of stars.

    This image composite was taken on Dec. 6, 2003, by Spitzer's infrared array camera, and is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

  6. Reading, Writing, and Rings!

    ERIC Educational Resources Information Center

    Aschbacher, Pamela; Li, Erika; Hammon, Art

    2008-01-01

    "Reading, Writing, and Rings!" was created by a team of elementary teachers, literacy experts, and scientists in order to integrate science and literacy. These free units bring students inside NASA's Cassini-Huygens mission to Saturn. The authors--a science teacher and education outreach specialist and two evaluators of educational programs--have…

  7. Ring laser scatterometer

    SciTech Connect

    Ackermann, Mark; Diels, Jean-Claude

    2005-06-28

    A scatterometer utilizes the dead zone resulting from lockup caused by scatter from a sample located in the optical path of a ring laser at a location where counter-rotating pulses cross. The frequency of one pulse relative to the other is varied across the lockup dead zone.

  8. Making Molecular Borromean Rings

    ERIC Educational Resources Information Center

    Pentecost, Cari D.; Tangchaivang, Nichol; Cantrill, Stuart J.; Chichak, Kelly S.; Peters, Andrea J.; Stoddart, Fraser J.

    2007-01-01

    A procedure that requires seven 4-hour blocks of time to allow undergraduate students to prepare the molecular Borromean rings (BRs) on a gram-scale in 90% yield is described. The experiment would serve as a nice capstone project to culminate any comprehensive organic laboratory course and expose students to fundamental concepts, symmetry point…

  9. Neptune may have polar rings

    NASA Astrophysics Data System (ADS)

    Dobrovolskis, A. R.; Steiman-Cameron, T. Y.; Borderies, N. J.

    1989-08-01

    Perturbations from Neptune's highly inclined satellite Triton can maintain rings passing nearly over Neptune's poles. These hypothetical polar rings are nearly perpendicular to Triton's orbit as well, and lie within several degrees of the plane of Voyager II's trajectory through the Neptunian system. Polar rings can coexist with equatorial rings at different radii. A randomly oriented torus of debris around Neptune has a probability of several percent to settle into a polar ring. Voyager II stands a significant chance of encountering a polar ring.

  10. Narrow rings - Observations and theory

    NASA Astrophysics Data System (ADS)

    Porco, C. C.

    Voyager 1 and 2 observations have revealed that within the rings of Saturn lies a set of narrow, eccentric rings resembling those of Uranus. Voyager 2 observations have proven crucial in refining the Uranian ring orbit models to a remarkable level of precision. All these rings share some common structural and kinematical characteristics, such as spatially variable radial widths and uniform precession; however, interesting differences exist which provoke attention and may be related to the differing dynamical environments in which these rings dwell. The current state of the knowledge of the shape, behavior, and confinement of narrow rings is discussed.

  11. The major influence of the atmosphere on intracranial pressure: an observational study

    NASA Astrophysics Data System (ADS)

    Herbowski, Leszek

    2016-06-01

    The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6 hPa (95 % CI 1004.5 to 1008.8 hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9 hPa (95 % CI 1006.3 to 1009.6 hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r = 0.87, p < 0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8 %). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

  12. Ring Bubbles of Dolphins

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  13. Rings from Close Encounters

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Weve recently discovered narrow sets of rings around two minor planets orbiting in our solar system. How did these rings form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected Ring SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow ring systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have rings. But how did these rings form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the rings were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of

  14. Saturn ring temperature changes before and after ring equinox

    NASA Astrophysics Data System (ADS)

    Spilker, Linda; Flandes, Alberto; Morishima, Ryuji; Leyrat, Cedric; Altobelli, Nicolas; Ferrari, Cecile; Brooks, Shawn; Pilorz, Stu

    2010-05-01

    The Cassini Composite infrared spectrometer (CIRS) retrieved the temperatures of Saturn's main rings at solar elevations ranging from 24 degrees to zero degrees at equinox (August 2009) as the sun traversed from the south to north side of the rings. Over this broad range of solar elevation the CIRS data show that the ring temperatures vary as much as 29K- 38K for the A ring, 22K-34K for the B ring and 18K-23K for the C ring. Interestingly the unlit sides of the rings show a similar decrease in temperature with the decreasing solar elevation. As equinox approached, the main rings cooled to their lowest temperatures measured to date. At equinox the solar input is very small and the primary heat sources for the rings are Saturn thermal and visible energy. Temperatures are almost identical for similar geometries on the north and south sides of the rings. The ring temperatures at equinox were: C ring, 55-75 K; B ring, 45-60 K; Cassini Division, 45 - 58 K; and A ring, 43 - 52 K. After Saturn equinox the solar elevation angle began to increase again and the temperatures on both the lit (north) and unlit (south) sides of the rings have begun to increase as well. Ring thermal models developed by Flandes and Morishima are able to reproduce most of the equinox temperatures observed by CIRS. Results before and after equinox will be presented. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and at CEA Saclay supported by the "Programme National de Planetologie". Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  15. [Intracranial dural arteriovenous fistula draining into spinal cord veins: case report].

    PubMed

    Seda, Lauro Franco; Pieruccetti, Marco Antonio; Freitas, José Maria Modenesi; Listik, Sérgio; Pereira, Clemente Augusto Brito

    2002-09-01

    We present an usual case of intracranial dural arteriovenous fistula with perimedullary and spinal cord venous plexus drainage and discuss its etiological, physiopathological, diagnostic and therapeutic aspects.

  16. Ring current development during high speed streams

    NASA Astrophysics Data System (ADS)

    Jordanova, V. K.; Matsui, H.; Puhl-Quinn, P. A.; Thomsen, M. F.; Mursula, K.; Holappa, L.

    2009-07-01

    Episodes of southward (Bz<0) interplanetary magnetic field (IMF) which lead to disturbed geomagnetic conditions are associated either with coronal mass ejections (CMEs) and possess long and continuous negative IMF Bz excursions, or with high speed solar wind streams (HSS) whose geoeffectiveness is due to IMF Bz profiles fluctuating about zero with various amplitudes and duration. We simulate ring current evolution during a HSS-driven storm that occurred during 24-26 October 2002 and compare its dynamics with a CME-driven storm of similar strength during 22-23 April 2001. We use our kinetic ring current-atmosphere interactions model (RAM), and investigate the mechanisms responsible for trapping particles and for causing their loss. Ring current evolution depends on the interplay of time-dependent inflow of plasma from the magnetotail, particle acceleration and loss (mainly due to charge exchange) along adiabatic drift paths, and outflow of plasma from the dayside magnetopause; all of these processes are incorporated in our model. We compare results from simulations using a newly developed, Cluster data based, University of New Hampshire inner magnetospheric electric field (UNH-IMEF) convection model with simulations using a Volland-Stern (V-S) type convection model. We find that, first, periods of increased magnetospheric convection coinciding with enhancements of plasma sheet density are needed for strong ring current buildup. Second, during the HSS-driven storm the convection potential from UNH-IMEF model is highly variable and causes sporadic shallow injections resulting in a weak ring current. The long period of enhanced convection during the CME-driven storm causes a continuous ion injection penetrating to lower L shells and stronger ring current buildup. V-S model predicts larger ring current injection during both storms. Third, the RAM driven by either convection model underestimates the total ring current energy during the recovery phase of the HSS storm

  17. Keck and VLT AO observations and models of the uranian rings during the 2007 ring plane crossings

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Dunn, David E.; Stam, Daphne M.; Showalter, Mark R.; Hammel, Heidi B.; Min, Michiel; Hartung, Markus; Gibbard, Seran G.; van Dam, Marcos A.; Matthews, Keith

    2013-11-01

    We present observations of the uranian ring system at a wavelength of 2.2 μm, taken between 2003 and 2008 with NIRC2 on the W.M. Keck telescope in Hawaii, and on 15-17 August 2007 with NaCo on the Very Large Telescope (VLT) in Chile. Of particular interest are the data taken around the time of the uranian ring plane crossing with Earth on 16 August 2007, and with the Sun (equinox) on 7 December 2007. We model the data at the different viewing aspects with a Monte Carlo model to determine: (1) the normal optical depth τ0, the location, and the radial extent of the main rings, and (2) the parameter Aτ0 (A is the particle geometric albedo), the location, and the radial plus vertical extent of the dusty rings. Our main conclusions are: (i) The brightness of the ɛ ring is significantly enhanced at small phase and ring inclination angles; we suggest this extreme opposition effect to probably be dominated by a reduction in interparticle shadowing. (ii) A broad sheet of dust particles extends inwards from the λ ring almost to the planet itself. This dust sheet has a vertical extent of ∼140 km, and Aτ0 = 2.2 × 10-6. (iii) The dusty rings between ring 4 and the α ring and between the α and β rings are vertically extended with a thickness of ∼300 km. (iv) The ζ ring extends from ∼41,350 km almost all the way inwards to the planet. The main ζ ring, centered at ∼39,500 km from the planet, is characterized by Aτ0 = 3.7 × 10-6; this parameter decreases closer to the planet. The ζ ring has a full vertical extent of order 800-900 km, with a pronounced density enhancement in the mid-plane. (v) The ηc ring is optically thin and less than several tens of km in the vertical direction. This ring may be composed of macroscopic material, surrounded by clumps of dust.

  18. Inorganic glass ceramic slip rings

    NASA Technical Reports Server (NTRS)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  19. Nonlinear density waves in planetary rings

    NASA Technical Reports Server (NTRS)

    Borderies, Nicole; Goldreich, Peter; Tremaine, Scott

    1986-01-01

    The steady-state structure of planetary rings in the presence of density waves at the Lindblad resonances of a satellite is indicated. The study is based on the dispersion relation and damping rate for nonlinear density waves, derived by Shu et al. (1985) and by Borderies, Goldreich, and Tremaine (1985). It is shown that strong density waves lead to an enhancement of the background surface density in the wave zone.

  20. Intracranial Metastatic Disease Spares the Limbic Circuit: A Review of 697 Metastatic Lesions in 107 Patients

    SciTech Connect

    Marsh, James C.; Herskovic, Arnold M.; Gielda, Benjamin T.; Hughes, Frank F.; Hoeppner, Thomas; Turian, Julius; Abrams, Ross A.

    2010-02-01

    Purpose: We report the incidence of metastatic involvement of the limbic circuit in a retrospective review of patients treated at our institution. This review was performed to assess the feasibility of selectively sparing the limbic system during whole-brain radiotherapy and prophylactic cranial irradiation. Methods and Materials: We identified 697 intracranial metastases in 107 patients after reviewing contrast-enhanced CT and/or MR image sets for each patient. Lesions were localized to the limbic circuit or to the rest of the brain/brain stem. Patients were categorized by tumor histology (e.g., non-small-cell lung cancer, small-cell lung cancer, breast cancer, and other) and by total number of intracranial metastases (1-3, oligometastatic; 4 or more, nonoligometastatic). Results: Thirty-six limbic metastases (5.2% of all metastases) were identified in 22 patients who had a median of 16.5 metastases/patient (limbic metastases accounted for 9.9% of their lesions). Sixteen metastases (2.29%) involved the hippocampus, and 20 (2.86%) involved the rest of the limbic circuit; 86.2% of limbic metastases occurred in nonoligometastatic patients, and 13.8% occurred in oligometastatic patients. The incidence of limbic metastases by histologic subtype was similar. The incidence of limbic metastases in oligometastatic patients was 4.9% (5/103): 0.97%, hippocampus; 3.9%, remainder of the limbic circuit. One of 53 oligometastatic patients (1.9%) had hippocampal metastases, while 4/53 (7.5%) had other limbic metastases. Conclusions: Metastatic involvement of the limbic circuit is uncommon and limited primarily to patients with nonoligometastatic disease, supporting our hypothesis that it is reasonable to selectively exclude or reduce the dose to the limbic circuit when treating patients with prophylactic cranial irradiation or whole-brain radiotherapy for oligometastatic disease not involving these structures.

  1. O-Ring-Testing Fixture

    NASA Technical Reports Server (NTRS)

    Turner, James E.; Mccluney, D. Scott

    1990-01-01

    Fixture used to evalute properties of O-rings of various materials. Hydraulic actuator positions plug in housing, creating controlled, variable gap in O-ring glands formed by grooves in plug and by inner wall of housing. Creates controlled axial and radial gaps between sealing surfaces around ring so effectiveness of material in maintaining seal determined under dynamic conditions.

  2. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    SciTech Connect

    Pugliese, D.; Stuchlík, Z. E-mail: zdenek.stuchlik@physics.cz

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  3. DC-Powered Jumping Ring

    ERIC Educational Resources Information Center

    Jeffery, Rondo N.; Farhang, Amiri

    2016-01-01

    The classroom jumping ring demonstration is nearly always performed using alternating current (AC), in which the ring jumps or flies off the extended iron core when the switch is closed. The ring jumps higher when cooled with liquid nitrogen (LN2). We have performed experiments using DC to power the solenoid and find similarities and significant…

  4. Vortex Rings in Superfluid Helium

    NASA Astrophysics Data System (ADS)

    Alamri, Sultan Z.; Barenghi, Carlo F.

    2008-11-01

    We present results of numerical simulations of large-scale vortex rings in superfluid helium. These large-scale vortex rings consists of many discrete (quantized) vortex filaments which interact with each other moving according to the Biot-Savart law. Lifetime, structural stability and speed of large-scale vortex rings will be discussed and compared to experimental results.

  5. Uranus: the rings are black.

    PubMed

    Sinton, W M

    1977-11-01

    An upper limit of 0.05 is established for the geometric albedo of the newly discovered rings of Uranus. In view of this very low albedo, the particles of the rings cannot be ice-covered as are those of rings A and B of Saturn.

  6. Satellite Rings Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.

    The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000.

    Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  7. Novel role for endogenous hepatocyte growth factor in the pathogenesis of intracranial aneurysms.

    PubMed

    Peña-Silva, Ricardo A; Chalouhi, Nohra; Wegman-Points, Lauren; Ali, Muhammad; Mitchell, Ian; Pierce, Gary L; Chu, Yi; Ballas, Zuhair K; Heistad, Donald; Hasan, David

    2015-03-01

    Inflammation plays a key role in formation and rupture of intracranial aneurysms. Because hepatocyte growth factor (HGF) protects against vascular inflammation, we sought to assess the role of endogenous HGF in the pathogenesis of intracranial aneurysms. Circulating HGF concentrations in blood samples drawn from the lumen of human intracranial aneurysms or femoral arteries were compared in 16 patients. Tissue from superficial temporal arteries and ruptured or unruptured intracranial aneurysms collected from patients undergoing clipping (n=10) were immunostained with antibodies to HGF and its receptor c-Met. Intracranial aneurysms were induced in mice treated with PF-04217903 (a c-Met antagonist) or vehicle. Expression of inflammatory molecules was also measured in cultured human endothelial, smooth muscle cells and monocytes treated with lipopolysaccharides in presence or absence of HGF and PF-04217903. We found that HGF concentrations were significantly higher in blood collected from human intracranial aneurysms (1076±656 pg/mL) than in femoral arteries (196±436 pg/mL; P<0.001). HGF and c-Met were detected by immunostaining in superficial temporal arteries and in both ruptured and unruptured human intracranial aneurysms. A c-Met antagonist did not alter the formation of intracranial aneurysms (P>0.05), but significantly increased the prevalence of subarachnoid hemorrhage and decreased survival in mice (P<0.05). HGF attenuated expression of vascular cell adhesion molecule-1 (P<0.05) and E-Selectin (P<0.05) in human aortic endothelial cells. In conclusion, plasma HGF concentrations are elevated in intracranial aneurysms. HGF and c-Met are expressed in superficial temporal arteries and in intracranial aneurysms. HGF signaling through c-Met may decrease inflammation in endothelial cells and protect against intracranial aneurysm rupture. PMID:25510828

  8. Room Temperature Aging Study of Butyl O-rings

    SciTech Connect

    Mark Wilson

    2009-08-07

    During testing under the Enhanced Surveillance Campaign in 2001, preliminary data detected a previously unknown and potentially serious concern with recently procured butyl o-rings. All butyl o-rings molded from a proprietary formulation throughout the period circa 1999 through 2001 had less than a full cure. Tests showed that sealing force values for these suspect o-rings were much lower than expected and their physical properties were very sensitive to further post curing at elevated temperatures. Further testing confirmed that these o-rings were approximately 50% cured versus the typical industry standard of > 90% cured. Despite this condition, all suspect o-rings fully conformed to their QC acceptance requirements, including their individual product drawing requirements.

  9. Oligomeric ferrocene rings.

    PubMed

    Inkpen, Michael S; Scheerer, Stefan; Linseis, Michael; White, Andrew J P; Winter, Rainer F; Albrecht, Tim; Long, Nicholas J

    2016-09-01

    Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category-differently sized rings comprising only 1,1'-disubstituted ferrocene units (cyclo[n], n = 5-7, 9). Due to the close proximity and connectivity of centres (covalent Cp-Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e(-) waves. Theoretical interrogations into correlations based on ring size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall ring charge and in conjunction with fast intramolecular electron transfer (∼10(7) s(-1)), these molecules can be considered as uniformly charged nanorings (diameter ∼1-2 nm). PMID:27554408

  10. Ideals of generalized matrix rings

    SciTech Connect

    Budanov, Aleksandr V

    2011-01-31

    Let R and S be rings, and {sub R}M{sub S} and {sub S}N{sub R} bimodules. In the paper, in terms of isomorphisms of lattices, relationships between the lattices of one-sided and two-sided ideals of the generalized matrix ring and the corresponding lattices of ideals of the rings R and S are described. Necessary and sufficient conditions for a pair of ideals I, J of rings R and S, respectively, to be the main diagonal of some ideal of the ring K are also obtained. Bibliography: 8 titles.

  11. O-Ring-Testing Fixture

    NASA Technical Reports Server (NTRS)

    Turner, James E.; Mccluney, D. Scott

    1991-01-01

    Fixture tests O-rings for sealing ability under dynamic conditions after extended periods of compression. Hydraulic cylinder moves plug in housing. Taper of 15 degrees on plug and cavity of housing ensures that gap created between O-ring under test and wall of cavity. Secondary O-rings above and below test ring maintain pressure applied to test ring. Evaluates effects of variety of parameters, including temperature, pressure, rate of pressurization, rate and magnitude of radial gap movement, and pretest compression time.

  12. New instability of Saturn's ring

    SciTech Connect

    Goertz, C.K.; Morfill, G.

    1988-05-01

    Perturbations in the Saturn ring's mass density are noted to be prone to instabilities through the sporadic elevation of submicron-size dust particles above the rings, which furnishes an effective angular momentum exchange between the rings and Saturn. The dust thus elevated from the ring settles back onto it at a different radial distance. The range of wavelength instability is determinable in light of the dust charge, the average radial displacement of the dust, and the fluctuation of these quantities. It is suggested that at least some of the B-ring's ringlets may arise from the instability.

  13. Helmet latching and attaching ring

    NASA Technical Reports Server (NTRS)

    Chase, E. W.; Viikinsalo, S. J. (Inventor)

    1970-01-01

    A neck ring releasably secured to a pressurized garment carries an open-ended ring normally in the engagement position fitted into an annular groove and adapted to fit into a complementary annular groove formed in a helmet. Camming means formed on the inner surface at the end of the helmet engages the open-ended ring to retract the same and allow for one motion donning even when the garment is pressurized. A projection on the end of the split ring is engageable to physically retract the split ring.

  14. Angioplasty or Stenting of Extra- and Intracranial Vertebral Artery Stenoses

    SciTech Connect

    Hauth, Elke A.M.; Gissler, H. Martin; Drescher, Robert; Jansen, Christian; Jaeger, Horst J.; Mathias, Klaus D.

    2004-01-15

    Purpose: To determine the feasibility and safety of angioplasty or angioplasty and stenting of extra- and intracranial vertebral artery (VA) stenosis. Methods: In 16 consecutive patients (9 men, 7 women; mean age 61 years, range 49-74 years) 16 stenotic VAs were treated with angioplasty orangioplasty and stenting. Eleven stenoses were localized in V1 segment,1 stenosis in V2 segment and 4 stenoses in V4 segment of VA. Fourteen VA stenoses were symptomatic, 2 asymptomatic. The etiology of the stenoses was atherosclerotic in all cases. Results:Angioplasty was performed in 8 of 11 V1 and 2 of 4 V4 segments of the VA. In 3 of 11 V1 segments and 2 of 4 V4 segments of the VA we combined angioplasty with stenting. The procedures were successfully performed in 14 of 16 VAs (87%). Complications were asymptomatic vessel dissection resulting in vessel occlusion in 1 of 11 V1 segments and asymptomatic vessel dissection in 2 of 4 V4 segments of the VA. One patient died in the 24-hr period after the procedure because of subarachnoid hemorrhage as a complication following vessel perforation of the treated V4 segment. Conclusion: Angioplasty orangioplasty and stenting of extracranial VA stenoses can be performed with a high technical success rate and a low complication rate. In intracranial VA stenosis the procedure is technically feasible but complications can be life-threatening. The durability and procedural complication rates of primary stenting without using predilation in extra- and intracranial VA stenosis should be defined in the future.

  15. Preclinical studies of photodynamic therapy of intracranial tissues

    NASA Astrophysics Data System (ADS)

    Lilge, Lothar D.; Sepers, Marja; Park, Jane; O'Carroll, Cindy; Pournazari, Poupak; Prosper, Joe; Wilson, Brian C.

    1997-05-01

    The applicability and limitations of the photodynamic threshold model were investigated for an intracranial tumor (VX2) and normal brain tissues in a rabbit model. Photodynamic threshold values for four different photosensitizers, i.e., Photofrin, 5(delta) -aminolaevulinic acid (5(delta) -ALA) induced Protoporphyrin IX (PPIX), Tin Ethyl Etiopurpurin (SnET2), and chloroaluminum phthalocyanine (AlClPc), were determined based on measured light fluence distributions, macroscopic photosensitizer concentration in various brain structures, and histologically determined extent of tissue necrosis following PDT. For Photofrin, AlClPc, and SnET2, normal brain displayed a significantly lower threshold value than VX2 tumor. For 5(delta) -ALA induced PPIX and SnET2 no or very little white matter damage, equalling to very high or infinite threshold values, was observed. Additionally, the latter two photosensitizers showed significantly lower uptake in white matter compared to other brain structures and VX2 tumor. Normal brain structures lacking a blood- brain-barrier, such as the choroid plexus and the meninges, showed high photosensitizer uptake for all photosensitizers, and, hence, are at risk when exposed to light. Results to date suggest that the photodynamic threshold values iares valid for white matter, cortex and VX2 tumor. For clinical PDT of intracranial neoplasms 5(delta) -ALA induced PPIX and SnET2 appear to be the most promising for selective tumor necrosis.However, the photosensitizer concentration in each normal brain structure and the fluence distribution throughout the treatment volume and adjacent tissues at risk must be monitored to maximize the selectivity of PDT for intracranial tumors.

  16. Interleukin-6 as a Prognostic Biomarker in Ruptured Intracranial Aneurysms

    PubMed Central

    Kao, Hung-Wen; Kuo, Chen-Ling; Huang, Ching-Shan; Tseng, Wan-Min; Lin, Ching-Po

    2015-01-01

    Background Interleukin-6 (IL-6), a proinflammatory cytokine, was found to surge in the cerebral spinal fluid after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that the plasma level of IL-6 could be an independent biomarker in predicting clinical outcome of patients with ruptured intracranial aneurysm. Methods We prospectively included 53 consecutive patients treated with platinum coil embolization of the ruptured intracranial aneurysm. Plasma IL-6 levels were measured in the blood samples at the orifices of the aneurysms and from peripheral veins. The outcome measure was the modified Rankin Scale one month after SAH. Multiple logistic regression analyses were used to evaluate the associations between the plasma IL-6 levels and the neurological outcome. Results Significant risk factors for the poor outcome were old age, low Glasgow Coma Scale (GCS) on day 0, high Fisher grades, and high aneurysmal and venous IL-6 levels in univariate analyses. Aneurysmal IL-6 levels showed modest to moderate correlations with GCS on day 0, vasospasm grade and Fisher grade. A strong correlation was found between the aneurysmal and the corresponding venous IL-6 levels (ρ = 0.721; P<0.001). In the multiple logistic regression models, the poor 30-day mRS was significantly associated with high aneurysmal IL-6 level (OR, 17.97; 95% CI, 1.51–214.33; P = 0.022) and marginally associated with high venous IL-6 level (OR, 12.71; 95% CI, 0.90–180.35; P = 0.022) after adjusting for dichotomized age, GCS on day 0, and vasospasm and Fisher grades. Conclusions The plasma level of IL-6 is an independent prognostic biomarker that could be used to aid in the identification of patients at high-risk of poor neurological outcome after rupture of the intracranial aneurysm. PMID:26176774

  17. Intracranial arterial variations: A comprehensive evaluation using CT angiography

    PubMed Central

    Kovač, Jelena Djokić; Stanković, Ana; Stanković, Danilo; Kovač, Bojan; Šaranović, Djordjije

    2014-01-01

    Background Intracranial arterial variations are a frequent finding in the general population. Knowledge of these vascular variations has significant clinical impact because some of them predispose patients to development of an aneurysm or cerebrovascular ischemic disease. The purpose of this study was to evaluate the frequency of intracranial vascular variations and associated vascular lesions on computed tomography angiography (CTA) examinations. Material/Methods CTA examinations performed by 16-detector computed tomography were prospectively reviewed in 455 patients for the presence of fenestrations, duplications, hypoplasia, aplasia, aneurysms, and other vascular lesions. Results Arterial fenestrations were found in 2.4% of patients, with the vertebrobasilar system as the most common location. The remaining fenestrations were located on the middle cerebral artery M1 segment (0.2%), anterior communicating artery (0.4%), and anterior cerebral artery A1 segment (0.6%). No associated aneurysms were noted in these patients. The prevalence of an azygos anterior cerebral artery was 1.5%. Bihemispheric anterior cerebral artery was found in 0.9%, hypoplastic A1 segment in 17.6%, and congenital absence of A1 segment in 0.4% of patients. Fetal origin of the posterior cerebral artery was found in 37% of cases. Hypoplastic vertebral artery terminating as posterior inferior cerebellar artery was observed in 9 patients, while transversal anastomosis between vertebral arteries was seen in only 1 patient. Conclusions CTA precisely demonstrates the diversity of intracranial arterial variations, whose overall frequency in this study is similar to previous radiological reports. Furthermore, our results do not show significant association between the frequency of aneurysms and cerebral arterial anomalies. PMID:24625840

  18. Quality of life in idiopathic intracranial hypertension at diagnosis

    PubMed Central

    Bruce, Beau B.; McDermott, Michael P.; Galetta, Kristin M.; Balcer, Laura J.; Wall, Michael

    2015-01-01

    Objective: The study purpose was to examine vision-specific and overall health-related quality of life (QOL) at baseline in Idiopathic Intracranial Hypertension Treatment Trial patients who were newly diagnosed and had mild visual loss. We also sought to determine the associations between vision-specific QOL scores and visual symptoms, visual function, pain, headache-related disability, and obesity. Methods: We assessed QOL using the 36-Item Short Form Health Survey, National Eye Institute Visual Function Questionnaire–25 (NEI-VFQ-25), and 10-Item NEI-VFQ-25 Neuro-Ophthalmic Supplement. We compared these results with those of previously reported idiopathic intracranial hypertension (IIH) QOL studies. We assessed relationships between QOL and other clinical characteristics. Results: Among 165 participants with IIH (161 women and 4 men with a mean age ± SD of 29.2 ± 7.5 years), vision-specific QOL scores were reduced compared with published values for disease-free controls. Scores of participants were comparable to published results for patients with multiple sclerosis and a history of optic neuritis. A multiple linear regression model for the NEI-VFQ-25 composite score found that perimetric mean deviation in the best eye, visual acuity in the worst eye, visual symptoms, and pain symptoms (headache, neck pain), but not obesity, were independently associated with QOL. Conclusions: IIH affects QOL at time of diagnosis even in patients with mild visual impairment. Vision-specific QOL in patients with newly diagnosed IIH may be as decreased as that for patients with other neuro-ophthalmic disorders. IIH treatment should target visual loss and other symptoms of increased intracranial pressure associated with reduced QOL. Reduced QOL does not simply reflect obesity, an underlying IIH risk factor. PMID:25995055

  19. Prognosis by tumor location in adults with intracranial ependymomas.

    PubMed

    Sayegh, Eli T; Aranda, Derick; Kim, Joseph M; Oh, Taemin; Parsa, Andrew T; Oh, Michael C

    2014-12-01

    Intracranial ependymomas are rare tumors in adults. Thus, factors affecting prognosis are poorly understood. We performed a study to investigate whether tumor location is an important prognostic factor in adults who undergo surgery for intracranial ependymomas. PubMed was searched to identify studies that reported clinical outcomes in adult patients with intracranial ependymoma. Data were extracted for patient and tumor characteristics, extent of resection, progression-free survival (PFS), and overall survival (OS). Tumors were categorized as supratentorial or infratentorial and extraventricular or intraventricular. Presenting clinical features and tumor characteristics were tabulated. Kaplan-Meier and multivariate Cox regression survival analyses were performed to determine PFS and OS by tumor location. Extent of resection was also analyzed by tumor location. A total of 183 patients were included in the meta-analysis. Patients presented at a mean of 8.2months with a myriad of clinical features. The mean tumor size was 3.38 cm, and 19.3% of tumors were cystic. Supratentorial tumors were most commonly located in the frontal and parietal lobes, and infratentorial tumors in the fourth ventricle. Supratentorial tumors demonstrated significantly poorer PFS (p<0.001) and OS (p=0.003) than infratentorial tumors, despite a higher rate of gross total resection (GTR) for the supratentorial tumors (72.6% versus 42.1%). Extraventricular ependymomas displayed significantly poorer PFS than intraventricular ependymomas (p=0.009). In summary, supratentorial ependymomas have significantly poorer PFS and OS than their infratentorial counterparts, despite being more conducive to GTR, suggesting increased clinical aggressiveness. Extraventricular location is also associated with significantly poorer PFS than intraventricular location.

  20. Intracranial growing teratoma syndrome: clinical characteristics and treatment strategy.

    PubMed

    Kim, Chae-Yong; Choi, Jung-Won; Lee, Ji Yeon; Kim, Seung-Ki; Wang, Kyu-Chang; Park, Sung-Hye; Choe, Gheeyoung; Ahn, Hyo Seop; Kim, Il-Han; Cho, Byung-Kyu

    2011-01-01

    This study evaluated the clinical and radiological characteristics, as well as the treatment outcomes, for the rare phenomenon known as intracranial growing teratoma syndrome (iGTS). One hundred seventy patients diagnosed with intracranial germ cell tumours (GCT) between 1997 and 2008 were enrolled in this retrospective analysis. Thorough reviews of medical records, brain magnetic resonance images (MRI), pathological findings and tumour markers [alpha-fetoprotein (αFP) and beta-human chorionic gonadotropin (βHCG)] were performed to identify the incidence of iGTS cases and to clarify their clinical characteristics. Eleven out of the 170 intracranial GCT patients (6.5%) were identified as having iGTS. All instances of iGTS originated from non-germinomatous GCT (NGGCT), with incidence rate of 21% (11/52). Six iGTS cases developed from mixed GCTs, four from immature teratomas (ITs) and one from yolk sac tumour. All 11 iGTS patients showed honeycomb-shaped multi-cystic growth patterns on MRI, which is a typical characteristic of iGTS. Surgical excision was performed in all patients, and complete excision was possible in nine patients. Eight of them are alive with no evidence of recurrence; however, two patients who had residual masses died owing to progression of iGTS. Early recognition and suspicion of iGTS, during or after adjuvant therapy of NGGCT, is crucial to ensure that surgical intervention can be performed in a timely manner. Early radical excision may be the treatment of choice for better iGTS prognosis. PMID:20532955

  1. Small Intracranial Aneurysm Treatment Using Target ® Ultrasoft ™ Coils

    PubMed Central

    Jindal, Gaurav; Miller, Timothy; Iyohe, Moronke; Shivashankar, Ravi; Prasad, Vikram; Gandhi, Dheeraj

    2016-01-01

    Purpose The introduction of small, soft, complex-shaped microcoils has helped facilitate the endovascular treatment of small intracranial aneurysms (IAs) over the last several years. Here, we evaluate the initial safety and efficacy of treating small IAs using only Target® Ultrasoft™ coils. Materials and methods A retrospective review of a prospectively maintained clinical database at a single, high volume, teaching hospital was performed from September 2011 to May 2015. IAs smaller than or equal to 5.0 mm in maximal dimension treated with only Target® Ultrasoft™ coils were included. Results A total of 50 patients with 50 intracranial aneurysms were included. Subarachnoid hemorrhage from index aneurysm rupture was the indication for treatment in 23 of 50 (46%) cases, and prior subarachnoid hemorrhage (SAH) from another aneurysm was the indication for treatment in eight of 50 (16%) cases. The complete aneurysm occlusion rate was 70% (35/50), the minimal residual aneurysm rate was 14% (7/50), and residual aneurysm rate was 16% (8/50). One intraoperative aneurysm rupture occurred. Three patients died during hospitalization from clinical sequelae of subarachnoid hemorrhage. Follow-up at a mean of 13.6 months demonstrated complete aneurysm occlusion in 75% (30/40) of cases, near complete occlusion in 15% (6/40) of cases, and residual aneurysm in 10% (4/40) of cases, all four of which were retreated. Conclusion Our initial results using only Target® Ultrasoft™ coils for the endovascular treatment of small intracranial aneurysms demonstrate initial excellent safety and efficacy profiles. PMID:27403224

  2. Non-Invasive Method of Determining Absolute Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

    2004-01-01

    A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

  3. Visceral larva migrans presenting as multiple intracranial and intraspinal abscesses.

    PubMed

    Moiyadi, Alefia; Mahadevan, Anita; Anandh, Balasubramaniam; Shivashankar, Ravi Shankar; Chickabasavaiah, Yasha Thagadur; Shankar, Susarla Krishna

    2007-08-01

    Involvement of nervous system by toxocariasis is rare and can produce a spectrum of pathology that includes eosinophillic meningoencephalitis, meningomyelitis, space occupying lesions, vasculitis causing seizures or behavioral abnormalities posing diagnostic dilemmas. We describe a 38-year-old man who presented with multiple intracranial and intramedullary abscesses caused by visceral larva migrans. Neurohelminthiasis as a cause of multiple abscesses, though rare, should be entertained as a differential diagnosis particularly in tropical South-east Asian countries where helminthiasis is still an epidemiological concern prevalent in the pediatric age group. PMID:17899691

  4. Computer-assisted volumetric resections of intracranial lesions

    NASA Astrophysics Data System (ADS)

    Castro-Moure, Federico; Zamorano, Lucia J.

    1993-09-01

    Computed tomographic (CT) and magnetic resonance imaging (MRI) studies reconstructed in a stereotactic space can be used for accurate localization of intracranial lesions located in deep or eloquent regions in the brain, and for optimization of subsequent surgical removal. We describe our experience with 163 patients who underwent computer-assisted volumetric resection. The planning for the stereotactic volumetric neurosurgical methodology utilized the Zamarano-Dujovny localizing unit, the neurosurgical planning software (NSPS) system, which generates 2-dimensional and 3-dimensional views of the area of surgical interest, the arc setting parameters, and reconstructed CT images corresponding to the surgeon's eye-view perspective.

  5. Non-invasive method of determining diastolic intracranial pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor); Hargens, Alan R. (Inventor)

    2004-01-01

    A method is presented for determining diastolic intracranial pressure (ICP) in a patient. A first change in the length of a path across the skull of the patient caused by a known change in ICP is measured and used to determine an elasticity constant for the patient. Next, a second change in the length of the path across the patient's skull occurring between systolic and diastolic portions of the patient's heartbeat is measured. The patient's diastolic ICP is a function of the elasticity constant and the second change.

  6. Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension.

    PubMed

    Hutchinson, Peter J; Kolias, Angelos G; Timofeev, Ivan S; Corteen, Elizabeth A; Czosnyka, Marek; Timothy, Jake; Anderson, Ian; Bulters, Diederik O; Belli, Antonio; Eynon, C Andrew; Wadley, John; Mendelow, A David; Mitchell, Patrick M; Wilson, Mark H; Critchley, Giles; Sahuquillo, Juan; Unterberg, Andreas; Servadei, Franco; Teasdale, Graham M; Pickard, John D; Menon, David K; Murray, Gordon D; Kirkpatrick, Peter J

    2016-09-22

    Background The effect of decompressive craniectomy on clinical outcomes in patients with refractory traumatic intracranial hypertension remains unclear. Methods From 2004 through 2014, we randomly assigned 408 patients, 10 to 65 years of age, with traumatic brain injury and refractory elevated intracranial pressure (>25 mm Hg) to undergo decompressive craniectomy or receive ongoing medical care. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOS-E) (an 8-point scale, ranging from death to "upper good recovery" [no injury-related problems]) at 6 months. The primary-outcome measure was analyzed with an ordinal method based on the proportional-odds model. If the model was rejected, that would indicate a significant difference in the GOS-E distribution, and results would be reported descriptively. Results The GOS-E distribution differed between the two groups (P<0.001). The proportional-odds assumption was rejected, and therefore results are reported descriptively. At 6 months, the GOS-E distributions were as follows: death, 26.9% among 201 patients in the surgical group versus 48.9% among 188 patients in the medical group; vegetative state, 8.5% versus 2.1%; lower severe disability (dependent on others for care), 21.9% versus 14.4%; upper severe disability (independent at home), 15.4% versus 8.0%; moderate disability, 23.4% versus 19.7%; and good recovery, 4.0% versus 6.9%. At 12 months, the GOS-E distributions were as follows: death, 30.4% among 194 surgical patients versus 52.0% among 179 medical patients; vegetative state, 6.2% versus 1.7%; lower severe disability, 18.0% versus 14.0%; upper severe disability, 13.4% versus 3.9%; moderate disability, 22.2% versus 20.1%; and good recovery, 9.8% versus 8.4%. Surgical patients had fewer hours than medical patients with intracranial pressure above 25 mm Hg after randomization (median, 5.0 vs. 17.0 hours; P<0.001) but had a higher rate of adverse events (16.3% vs. 9.2%, P=0.03). Conclusions At 6

  7. Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension.

    PubMed

    Hutchinson, Peter J; Kolias, Angelos G; Timofeev, Ivan S; Corteen, Elizabeth A; Czosnyka, Marek; Timothy, Jake; Anderson, Ian; Bulters, Diederik O; Belli, Antonio; Eynon, C Andrew; Wadley, John; Mendelow, A David; Mitchell, Patrick M; Wilson, Mark H; Critchley, Giles; Sahuquillo, Juan; Unterberg, Andreas; Servadei, Franco; Teasdale, Graham M; Pickard, John D; Menon, David K; Murray, Gordon D; Kirkpatrick, Peter J

    2016-09-22

    Background The effect of decompressive craniectomy on clinical outcomes in patients with refractory traumatic intracranial hypertension remains unclear. Methods From 2004 through 2014, we randomly assigned 408 patients, 10 to 65 years of age, with traumatic brain injury and refractory elevated intracranial pressure (>25 mm Hg) to undergo decompressive craniectomy or receive ongoing medical care. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOS-E) (an 8-point scale, ranging from death to "upper good recovery" [no injury-related problems]) at 6 months. The primary-outcome measure was analyzed with an ordinal method based on the proportional-odds model. If the model was rejected, that would indicate a significant difference in the GOS-E distribution, and results would be reported descriptively. Results The GOS-E distribution differed between the two groups (P<0.001). The proportional-odds assumption was rejected, and therefore results are reported descriptively. At 6 months, the GOS-E distributions were as follows: death, 26.9% among 201 patients in the surgical group versus 48.9% among 188 patients in the medical group; vegetative state, 8.5% versus 2.1%; lower severe disability (dependent on others for care), 21.9% versus 14.4%; upper severe disability (independent at home), 15.4% versus 8.0%; moderate disability, 23.4% versus 19.7%; and good recovery, 4.0% versus 6.9%. At 12 months, the GOS-E distributions were as follows: death, 30.4% among 194 surgical patients versus 52.0% among 179 medical patients; vegetative state, 6.2% versus 1.7%; lower severe disability, 18.0% versus 14.0%; upper severe disability, 13.4% versus 3.9%; moderate disability, 22.2% versus 20.1%; and good recovery, 9.8% versus 8.4%. Surgical patients had fewer hours than medical patients with intracranial pressure above 25 mm Hg after randomization (median, 5.0 vs. 17.0 hours; P<0.001) but had a higher rate of adverse events (16.3% vs. 9.2%, P=0.03). Conclusions At 6

  8. Infantile intracranial aneurysm of the superior cerebellar artery.

    PubMed

    Del Santo, Molly Ann; Cordina, Steve Mario

    2016-01-01

    Intracranial aneurysms in the pediatric population are rare. We report a case of a 3-month-old infant who presented with inconsolable crying, vomiting, and sunset eye sign. CT revealed a subarachnoid hemorrhage, with CT angiogram revealing a superior cerebellar artery aneurysm. An external ventricular drain was placed for acute management of hydrocephalus, with definitive treatment by endovascular technique with a total of six microcoils to embolize the aneurysm. Serial transcranial Dopplers revealed no subsequent vasospasm. Although aneurysms in the pediatric population are rare, once the diagnosis is established, early treatment results in better outcomes. PMID:26929222

  9. Intracranial myiasis by Hypoderma bovis (Linnaeus) in a horse.

    PubMed

    Hadlow, W J; Ward, J K; Krinsky, W L

    1977-04-01

    Acute neurologic disease associated with intracranial migration of a first instar larva of a warble fly, Hypoderma bovis (Linnaeus), was observed in a 14-year-old Quarter Horse gelding in western Montana. The disease was characterized by incoordination of gait, circling to the left, head tilt to the right, partial paralysis of the right side of the face, and impaired vision in the right eye. Two and one-half hours after it was first noticed sick, the horse collapsed and was euthanized. Massive hemorrhage unaccompanied by necrosis or significant cellular response was present in the right side of the midbrain and pons.

  10. Thrombosis modeling in intracranial aneurysms: a lattice Boltzmann numerical algorithm

    NASA Astrophysics Data System (ADS)

    Ouared, R.; Chopard, B.; Stahl, B.; Rüfenacht, D. A.; Yilmaz, H.; Courbebaisse, G.

    2008-07-01

    The lattice Boltzmann numerical method is applied to model blood flow (plasma and platelets) and clotting in intracranial aneurysms at a mesoscopic level. The dynamics of blood clotting (thrombosis) is governed by mechanical variations of shear stress near wall that influence platelets-wall interactions. Thrombosis starts and grows below a shear rate threshold, and stops above it. Within this assumption, it is possible to account qualitatively well for partial, full or no occlusion of the aneurysm, and to explain why spontaneous thrombosis is more likely to occur in giant aneurysms than in small or medium sized aneurysms.

  11. Intracranial Aneurysms: Wall Motion Analysis for Prediction of Rupture.

    PubMed

    Vanrossomme, A E; Eker, O F; Thiran, J-P; Courbebaisse, G P; Zouaoui Boudjeltia, K

    2015-10-01

    Intracranial aneurysms are a common pathologic condition with a potential severe complication: rupture. Effective treatment options exist, neurosurgical clipping and endovascular techniques, but guidelines for treatment are unclear and focus mainly on patient age, aneurysm size, and localization. New criteria to define the risk of rupture are needed to refine these guidelines. One potential candidate is aneurysm wall motion, known to be associated with rupture but difficult to detect and quantify. We review what is known about the association between aneurysm wall motion and rupture, which structural changes may explain wall motion patterns, and available imaging techniques able to analyze wall motion. PMID:25929878

  12. Intracranial venous sinus thrombosis complicating AIDS-associated nephropathy.

    PubMed

    Afsari, Khosrow; Frank, Jeffrey; Vaksman, Yulia; Nguyen, Thanhan V

    2003-03-01

    An alert and oriented 27-year-old African American woman with AIDS presented with a 10-day history of fever, cough productive of yellow sputum, nausea, and vomiting and a 1-day history of excruciating headache and photophobia. Her condition rapidly deteriorated into a coma with decorticate and then decerebrate posture, and she died 3 weeks later. There was evidence of extensive intracranial venous sinus thrombosis (ICVST), renal vein thrombosis (RVT), and multiple cerebral hemorrhagic infarcts due to a hypercoagulable state complicating AIDS-associated nephrotic syndrome. This is the first reported case of fatal ICVST and RVT with extensive cerebral hemorrhagic infarcts complicating nephrotic syndrome in a patient with AIDS.

  13. Spontaneous Intracranial Hypotension Associated with Kinetic Tremor and Ataxia

    PubMed Central

    Salazar, Richard

    2016-01-01

    Background Spontaneous intracranial hypotension (SIH) is a clinically variable syndrome caused by low cerebrospinal fluid (CSF) pressure due to a non-traumatic CSF leak. Phenomenology Shown This case describes a 68-year-old gentleman who presents with chronic and slightly progressive kinetic tremor of bilateral hands associated with gait ataxia and gait start hesitation. Educational Value This case underscores the importance of having a high index of suspicion for the diagnosis of SIH when encountering a patient presenting with late-onset progressive kinetic tremor and gait ataxia syndrome. PMID:27351232

  14. Hypervitaminosis A causing benign intracranial hypertension. A case report.

    PubMed

    Bhettay, E M; Bakst, C M

    1988-12-01

    Hypervitaminosis A is a well-recognized clinical entity, but the toxic manifestations develop so insidiously and involve so many systems that diagnosis can easily be missed or delayed. A patient with juvenile chronic arthritis developed benign intracranial hypertension and other manifestations of excessive vitamin A intake and made a complete recovery after it was withdrawn. Vitamin A is a non-prescription drug and any history of its ingestion must be obtained during evaluation of papilloedema. A plea is made for the public to be repeatedly reminded that no proposed remedy is safe or effective until it is demonstrated to be so. PMID:3194809

  15. Multiple intracranial hemorrhages in pregnancy: A common autoimmune etiology.

    PubMed

    Pahadiya, Hans Raj; Lakhotia, Manoj; Gandhi, Ronak; Choudhary, Akanksha; Madan, Shiva

    2016-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disorder, primarily affect female in fertile age. Pregnancy in SLE female is a high-risk situation which can adversely affect maternal-fetal dyad. SLE can flare during pregnancy or in postpartum period. We describe a case of a young pregnant female who presented because of right hemiparesis due multiple hemorrhages in the brain. The first presentation of the SLE with multiple intracranial hemorrhages in pregnancy, preceding the other characteristic clinical symptoms is rare. Here, we high lighten the major neurological issues and maternal-fetal dyad issues in SLE pregnancy and treatment strategies for management of SLE in pregnancy. PMID:27114665

  16. Infantile intracranial aneurysm of the superior cerebellar artery.

    PubMed

    Del Santo, Molly Ann; Cordina, Steve Mario

    2016-02-29

    Intracranial aneurysms in the pediatric population are rare. We report a case of a 3-month-old infant who presented with inconsolable crying, vomiting, and sunset eye sign. CT revealed a subarachnoid hemorrhage, with CT angiogram revealing a superior cerebellar artery aneurysm. An external ventricular drain was placed for acute management of hydrocephalus, with definitive treatment by endovascular technique with a total of six microcoils to embolize the aneurysm. Serial transcranial Dopplers revealed no subsequent vasospasm. Although aneurysms in the pediatric population are rare, once the diagnosis is established, early treatment results in better outcomes.

  17. Multiple intracranial hemorrhages in pregnancy: A common autoimmune etiology

    PubMed Central

    Pahadiya, Hans Raj; Lakhotia, Manoj; Gandhi, Ronak; Choudhary, Akanksha; Madan, Shiva

    2016-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disorder, primarily affect female in fertile age. Pregnancy in SLE female is a high-risk situation which can adversely affect maternal-fetal dyad. SLE can flare during pregnancy or in postpartum period. We describe a case of a young pregnant female who presented because of right hemiparesis due multiple hemorrhages in the brain. The first presentation of the SLE with multiple intracranial hemorrhages in pregnancy, preceding the other characteristic clinical symptoms is rare. Here, we high lighten the major neurological issues and maternal-fetal dyad issues in SLE pregnancy and treatment strategies for management of SLE in pregnancy. PMID:27114665

  18. Colloid cyst mimicking intracranial hemorrhage after head trauma.

    PubMed

    Buyukkaya, Ayla; Buyukkaya, Ramazan; Özel, Mehmet Ali; Sarıtas, Ayhan

    2015-02-01

    Trauma patients consist vast majority of the patients who admit to emergency department, and most of them have a head trauma. A 58-year-old patient was taken to emergency department with head trauma, and a hyperdense lesion neighboring to third ventricle was detected. A diagnosis of colloid cyst was made in the patient who was being followed up for hemorrhage. In patients with head trauma, colloid cyst may easly be confused with intracranial hemorrhage due to hyperdensity. The aim of this report is to emphasize the importance of clinical thinking in the differential diagnosis of hyperdense lesion on computed tomography imaging of a patient with head injury.

  19. Volumetric relief map for intracranial cerebrospinal fluid distribution analysis.

    PubMed

    Lebret, Alain; Kenmochi, Yukiko; Hodel, Jérôme; Rahmouni, Alain; Decq, Philippe; Petit, Éric

    2015-09-01

    Cerebrospinal fluid imaging plays a significant role in the clinical diagnosis of brain disorders, such as hydrocephalus and Alzheimer's disease. While three-dimensional images of cerebrospinal fluid are very detailed, the complex structures they contain can be time-consuming and laborious to interpret. This paper presents a simple technique that represents the intracranial cerebrospinal fluid distribution as a two-dimensional image in such a way that the total fluid volume is preserved. We call this a volumetric relief map, and show its effectiveness in a characterization and analysis of fluid distributions and networks in hydrocephalus patients and healthy adults.

  20. PET examination in intracranial tumor diagnosis of a cat

    SciTech Connect

    Angyal, G.; Csepura, G.; Balkay, L.; Galuska, L.; Molnar, J.; Valastyan, I.

    2008-12-08

    This paper shows the significance of the Positron Emission Tomography (PET) in the veterinary medication through a case study of a cat brain tumor. A castrated male cat with bilateral mydriasis and blindness arrived at the veterinary clinic. After physical, laboratory and neurological investigations other sickness was ruled out and the inkling of the intracranial lesion had come to light. Brain tumor seemed the most likely to cause the illness because other symptoms appeared (for example: anorexia, depression) and they progrediated fast. PET examination, using {sup 18}F-FDG isotope, was performed to confirm the possible causes of the cat's symptoms.

  1. PET examination in intracranial tumor diagnosis of a cat

    NASA Astrophysics Data System (ADS)

    Angyal, G.; Csepura, G.; Balkay, L.; Galuska, L.; Molnár, J.; Valastyán, I.

    2008-12-01

    This paper shows the significance of the Positron Emission Tomography (PET) in the veterinary medication through a case study of a cat brain tumor. A castrated male cat with bilateral mydriasis and blindness arrived at the veterinary clinic. After physical, laboratory and neurological investigations other sickness was ruled out and the inkling of the intracranial lesion had come to light. Brain tumor seemed the most likely to cause the illness because other symptoms appeared (for example: anorexia, depression) and they progrediated fast. PET examination, using 18F-FDG isotope, was performed to confirm the possible causes of the cat's symptoms

  2. Thinking outside the box: Use of the pressure wire to assess intracranial large artery stenoses.

    PubMed

    Sanon, Vani P; Prasad, Anand

    2016-08-01

    A novel study investigating the utility of the 0.014″ diameter pressure wire to assess the hemodynamic significance of intermediate intracranial stenosis. Technical aspects of pressure wire positioning across intracranial arteries are described. Further research is required to clarify the assessment of pressure gradients in the cerebral circulation and to define the optimal threshold for intervention. PMID:27530191

  3. Limitations of using a cancer registry to identify incident primary intracranial tumours

    PubMed Central

    Counsell, C.; Collie, D.; Grant, R.

    1997-01-01

    The completeness and accuracy of registration of primary intracranial tumours in the Scottish Cancer Registry was compared with a detailed incidence study performed over a two year period (1989-90). Of 228 patients with any primary intracranial tumour in the incidence study, 124 (54%) were identified as intracranial tumours in the cancer registry. The registry excluded benign tumours (although this was not consistent) and so the sensitivity of the registry varied with tumour type (84% for neuroepithelial tumours, 22% meningeal, 29% sellar, 0% cranial nerve). Of the 31 malignant tumours not found in the registry on our initial search, nine were found to have been included between 1989-90 but using different International Classification of Diseases-9th revision (ICD-9) codes or postcodes, and seven were found registered after 1990.Eleven per cent of cases (18/170) identified in the cancer registry were excluded from the incidence study: 11 had evidence of an intracranial tumour before 1989 whereas four definitely did not have an intracranial tumour. The cancer registry therefore significantly underestimated the incidence of all primary intracranial tumours, and of malignant intracranial tumours. Incidence studies must use additional methods to identify all primary tumours. Cancer registries should consider registering all primary intracranial tumours and may improve case ascertainment by screening neuroradiology data.

 PMID:9221974

  4. Evolution of an elliptic vortex ring in a viscous fluid

    NASA Astrophysics Data System (ADS)

    Cheng, M.; Lou, J.; Lim, T. T.

    2016-03-01

    The evolution of a viscous elliptic vortex ring in an initially quiescent fluid or a linear shear flow is numerically simulated using a lattice Boltzmann method. A wide range of parameters are considered, namely, aspect ratios (AR) (1 ≤ AR ≤ 8), core radius to ring radius ratios (σ0) (0.1 ≤ σ0 ≤ 0.3), Reynolds number (Re) (500 ≤ Re ≤ 3000), and shear rate (K) (0 ≤ K ≤ 0.12). The study aims to fill the gap in the current knowledge of the dynamics of an elliptic vortex ring in a viscous fluid and also to address the issue of whether an elliptic ring undergoes vortex stretching and compression during axis-switching. In a quiescent fluid, results show that for fixed Re and σ0, there exists a critical aspect ratio (ARc), below which an elliptic ring undergoes oscillatory deformation with the period that increases with increasing AR. Above ARc, the vortex ring breaks up into two or three sub-rings after the first half-cycle of oscillation. While higher Reynolds number enhances vortex ring breakup, larger core size has the opposite effect. Contrary to an inviscid theory, an elliptic ring does undergo vortex stretching and compression during oscillatory deformation. In the presence of a linear shear flow, the vortex ring undergoes not only oscillatory deformation and stretching but also tilting as it propagates downstream. The tilting angle increases with the shear rate K and is responsible for inducing a "tail" that consists of a counter-rotating vortex pair (CVP) near the upstream end of the initial major axis after the first half-cycle of oscillation. For a high shear rate, the CVP wraps around the ring and transforms its topological structure from a simple elliptic geometry to a complicated structure that eventually leads to the generation of turbulence.

  5. A Low-Cost iPhone-Assisted Augmented Reality Solution for the Localization of Intracranial Lesions

    PubMed Central

    Zhu, RuYuan; Chen, XiaoLei; Zhang, Jun

    2016-01-01

    Background Precise location of intracranial lesions before surgery is important, but occasionally difficult. Modern navigation systems are very helpful, but expensive. A low-cost solution that could locate brain lesions and their surface projections in augmented reality would be beneficial. We used an iPhone to partially achieve this goal, and evaluated its accuracy and feasibility in a clinical neurosurgery setting. Methodology/Principal Findings We located brain lesions in 35 patients, and using an iPhone, we depicted the lesion’s surface projection onto the skin of the head. To assess the accuracy of this method, we pasted computed tomography (CT) markers surrounding the depicted lesion boundaries on the skin onto 15 patients. CT scans were then performed with or without contrast enhancement. The deviations (D) between the CT markers and the actual lesion boundaries were measured. We found that 97.7% of the markers displayed a high accuracy level (D ≤ 5mm). In the remaining 20 patients, we compared our iPhone-based method with a frameless neuronavigation system. Four check points were chosen on the skin surrounding the depicted lesion boundaries, to assess the deviations between the two methods. The integrated offset was calculated according to the deviations at the four check points. We found that for the supratentorial lesions, the medial offset between these two methods was 2.90 mm and the maximum offset was 4.2 mm. Conclusions/Significance This low-cost, image-based, iPhone-assisted, augmented reality solution is technically feasible, and helpful for the localization of some intracranial lesions, especially shallow supratentorial intracranial lesions of moderate size. PMID:27454518

  6. Porous silicon ring resonator for compact, high sensitivity biosensing applications

    DOE PAGES

    Rodriguez, Gilberto A.; Hu, Shuren; Weiss, Sharon M.

    2015-01-01

    A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resonators with a radius of 25 μm. A bulk detection sensitivity of 380 nm/RIU was measured upon exposure to salt water solutions. Specific detection of nucleic acid molecules was demonstrated with a surface detection sensitivity of 4 pm/nM.

  7. Ring resonator based narrow-linewidth semiconductor lasers

    NASA Technical Reports Server (NTRS)

    Ksendzov, Alexander (Inventor)

    2005-01-01

    The present invention is a method and apparatus for using ring resonators to produce narrow linewidth hybrid semiconductor lasers. According to one embodiment of the present invention, the narrow linewidths are produced by combining the semiconductor gain chip with a narrow pass band external feedback element. The semi conductor laser is produced using a ring resonator which, combined with a Bragg grating, acts as the external feedback element. According to another embodiment of the present invention, the proposed integrated optics ring resonator is based on plasma enhanced chemical vapor deposition (PECVD) SiO.sub.2 /SiON/SiO.sub.2 waveguide technology.

  8. Calculating Ring Pucker Free Energy Surfaces From Reaction Coordinate Forces

    SciTech Connect

    Barnett, Christopher B.; Naidoo, Kevin J.

    2009-03-09

    We implemented the free energy from adaptive reaction coordinate forces (FEARCF) method and applied it to the conformational investigation of carbohydrate ring puckering. The method allows for significantly enhanced sampling of reaction coordinate space. The free energies associated with the ring pucker motion of {beta}-D-ribose (a furanose) and {beta}-D-glucose (a pyranose) were calculated. These can be used to interpret catalytic mechanisms of glycosylases.

  9. Resonance-Enhanced Raman Scattering of Ring-Involved Vibrational Modes in the (1)B(2u) Absorption Band of Benzene, Including the Kekule Vibrational Modes ν(9) and ν(10).

    PubMed

    Willitsford, Adam H; Chadwick, C Todd; Kurtz, Stewart; Philbrick, C Russell; Hallen, Hans

    2016-02-01

    Resonance Raman spectroscopy provides much stronger Raman signal levels than its off-resonant counterpart and adds selectivity by excitation tuning. Raman preresonance of benzene has been well studied. On-resonance studies, especially at phonon-allowed absorptions, have received less attention. In this case, we observe resonance of many of the vibration modes associated motion of the carbons in the ring while tuning over the (1)B2u absorption, including the related ν9 (CC stretch Herzberg notation, ν14 Wilson notation) and ν10 (CH-parallel bend Herzberg notation, ν15 Wilson notation) vibrational modes along with the ν2 (CC-stretch or ring-breathing Herzberg notation, ν1 Wilson notation) mode and multiples of the ν18 (CCC-parallel bend Herzberg notation, ν6 Wilson notation) vibrational mode. The ring-breathing mode is found to mix with the b2u modes creating higher frequency composites. Through the use of an optical parametric oscillator (OPO) to tune through the (1)B2u absorption band of liquid benzene, a stiffening (increase in energy) of the vibrational modes is observed as the excitation wavelength nears the (1)B2u absorption peak of the isolated molecule (vapor) phase. The strongest resonance amplitude observed is in the 2 × ν18 (e2g) mode, with nearly twice the intensity of the ring-breathing mode, ν2. Several overtones and combination modes, especially with ν2 (a1g), are also observed to resonate. Raman resonances on phonon-allowed excitations are narrow and permit the measurement of vibrations not Raman-active in the ground state. PMID:26731431

  10. Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms: options, technical challenges, and results in 35 patients.

    PubMed

    Abla, Adib A; McDougall, Cameron M; Breshears, Jonathan D; Lawton, Michael T

    2016-05-01

    OBJECT Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed. METHODS Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA's origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included. RESULTS During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients. CONCLUSIONS PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one

  11. Continuous ring furnaces

    SciTech Connect

    De Stefani, G.; Genevois, J.L.; Paolo, P.

    1981-01-06

    A smoke conducting apparatus for use particularly with continuous ring furnaces (e.g., Hoffman furnaces) wherein each furnace chamber is connected to the smoke channel, the latter being a metal pipe inclined slightly from horizontal and provided with one or more traps along the length of its bottom surface, each trap containing a removable receptacle, and heating means being disposed along the bottom of the channel to fluidize tarry deposits of combustion products so that such deposits will flow by gravity into the removable receptacle.

  12. Parameter Optimization for Selected Correlation Analysis of Intracranial Pathophysiology

    PubMed Central

    Faltermeier, Rupert; Proescholdt, Martin A.; Bele, Sylvia; Brawanski, Alexander

    2015-01-01

    Recently we proposed a mathematical tool set, called selected correlation analysis, that reliably detects positive and negative correlations between arterial blood pressure (ABP) and intracranial pressure (ICP). Such correlations are associated with severe impairment of the cerebral autoregulation and intracranial compliance, as predicted by a mathematical model. The time resolved selected correlation analysis is based on a windowing technique combined with Fourier-based coherence calculations and therefore depends on several parameters. For real time application of this method at an ICU it is inevitable to adjust this mathematical tool for high sensitivity and distinct reliability. In this study, we will introduce a method to optimize the parameters of the selected correlation analysis by correlating an index, called selected correlation positive (SCP), with the outcome of the patients represented by the Glasgow Outcome Scale (GOS). For that purpose, the data of twenty-five patients were used to calculate the SCP value for each patient and multitude of feasible parameter sets of the selected correlation analysis. It could be shown that an optimized set of parameters is able to improve the sensitivity of the method by a factor greater than four in comparison to our first analyses. PMID:26693250

  13. Subarachnoid hemorrhage from intracranial aneurysms during pregnancy and the puerperium.

    PubMed

    Kataoka, Hiroharu; Miyoshi, Takekazu; Neki, Reiko; Yoshimatsu, Jun; Ishibashi-Ueda, Hatsue; Iihara, Koji

    2013-01-01

    Subarachnoid hemorrhage (SAH) due to the rupture of an intracranial aneurysm (IA) is a rare but serious complication of pregnancy and is responsible for important morbidity and mortality during pregnancy. This study reviewed reports of ruptured IA during pregnancy and the puerperium, and our own cases of ruptured IA in pregnant women. Hemorrhage occurred predominantly during the third trimester of pregnancy, when maternal cardiac output and blood volume increase and reach maximum. Physiological and hormonal changes in pregnancy are likely to affect the risk of IA rupture. Ruptured IAs during pregnancy should be managed based on neurosurgical considerations, and the obstetrical management of women with ruptured IAs should be decided according to the severity of SAH and the gestational age. Emergent cesarean section followed by clipping or coiling of aneurysms is indicated if the maternal condition and the gestational age allow such interventions. Although SAH during pregnancy can result in disastrous outcomes, the necessity of intracranial screening for high-risk pregnant women is still controversial. PMID:23979051

  14. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement

    PubMed Central

    Hussain, Ahmad S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates. PMID:27672529

  15. Intracranial teratoma in children: the role of chromosome 21 trisomy.

    PubMed

    Ferraz, Sabrine Teixeira; Valera, Elvis Terci; Brassesco, María Sol; Santos de Oliveira, Ricardo; Carlos dos Santos, Antonio; Saggioro, Fabiano Pinto; Neder, Luciano; Scrideli, Carlos Alberto; Tone, Luiz Gonzaga

    2014-04-01

    Teratomas are very rare intracranial tumors and cytogenetic information on this group remains rare. We report a case of a mature teratoma with abnormal +21 trisomy in tumor karyotype ocurring in a non-Down syndrome(DS) infant. Additionally, the evidence for the contribution of chromosome 21 trisomy in this neoplasia are briefly reviewed. The 6-month-old male baby presented with a posterior fossa tumor. Histological evaluation of tumor specimen showed a mature teratoma composed of fully differentiated ectodermal, mesodermal and endodermal components. Although somatic karyotyping of the index case was normal, composite tumor karyotype depicted 47,XY,+21[6]/46,XY[6]. Besides previous reports of children with DS and intracranial teratomas, this is the first report to describe the occurrence of an isolated chromosome 21 trisomy within the tumor of a non-DS child. The participation of chromosome 21 in this rare pediatric tumor, either somatic or restricted to tumor specimen,may deserve special interest and further investigation. PMID:24812702

  16. Visual Impairment and Intracranial Hypertension: An Emerging Spaceflight Risk

    NASA Technical Reports Server (NTRS)

    Fogarty, Jennifer A.; Polk, J. D.; Tarver, W.; Gibson, C. R.; Sargsyan, A.; Taddeo, T.; Alexander, D.; Otto, C.

    2010-01-01

    What is the risk? Given that astronauts exposed to microgravity experience a cephalad fluid shift, and that both symptomatic and asymptomatic astronauts have exhibited optic nerve sheath edema on MRI, there is a high probability that all astronauts have some degree of increased intracranial pressure (ICP; intracranial hypertension), and that those susceptible (via eye architecture, anatomy, narrow optic disc) have a high likelihood of developing papilledema (optic disc edema, globe flattening), choroidal folds, and/or hyperopic shifts and that the degree of edema may determine long-term or permanent vision impairment or loss. Back to back panels on this topic have been developed to address this emerging risk. The first panel will focus on the 6 clinical cases with emphasis on ophthalmic findings and imaging techniques used pre-, in-, and post-flight. The second panel will discuss the operational mitigation and medical requirements, the potential role of CO2 on ISS, and the research approach being developed. In total these back to back panels will explore what is known about this risk, what has been done immediately to address it, and how an integrated research model is being developed.

  17. Radiotherapy-related intracranial aneurysms: A role for conservative management

    PubMed Central

    Parag, Sayal; Arif, Zafar; Chittoor, Rajaraman

    2016-01-01

    Background: Radiotherapy-related intracranial aneurysms are a recognized but rare phenomenon and often present following rupture leading to subarachnoid hemorrhage. Treatment poses a particular dilemma and both endovascular, and surgical approaches have been used with varied success. We present the case of a radiotherapy-related aneurysm treated conservatively with a favorable outcome. Case Description: A 37-year-old man was diagnosed with a left temporal lobe mass for which he underwent an uneventful craniotomy and debulking. Histology revealed Grade III anaplastic astrocytoma following which he received radiotherapy. Three years later, he presented with subacute headache and transient dysphasia. Computed tomography and catheter angiography revealed a fusiform aneurysm of the supramarginal branch of the left middle cerebral artery with probable intra-aneurysmal thrombus. Adjacent vessels also showed mild vasculitic changes. Trial balloon occlusion of the parent vessel resulted in profound dysphasia and was therefore abandoned. Bypass surgery or stent placement was deemed to have too high a risk of neurological deficit, and keeping in mind, the diagnosis of anaplastic astrocytoma, conservative management was pursued with partial thrombosis noted on serial imaging and stable appearances subsequently at 42 months’ follow-up. Conclusion: Conservative management can be pursued in selective cases of radiotherapy-related aneurysms, particularly if the risk of treating is too high and in the context of intracranial malignancy with limited lifespan. PMID:27313964

  18. Latency relationships between cerebral blood flow velocity and intracranial pressure.

    PubMed

    Asgari, Shadnaz; Vespa, Paul M; Bergsneider, Marvin; Hu, Xiao

    2012-01-01

    Pulsatile intracranial pressure (ICP) is a key to the understanding of several neurological disorders in which compliance is altered, e.g., hydrocephalus. A recently proposed model suggests that ICP pulse is a standing wave and not a transmitted wave. The present work, aimed at obtaining a better understanding of the pulsatility in the cranium, tries to test the following hypotheses: first, ICP pulse onset latency would be lower than that of cerebral blood flow velocity (CBFV) pulses measured at a distal vessel; second, CBFV pulse at different intracranial arteries will have different pulse onset latencies, and hence they are not generated as a standing wave. The dataset used in the present study consists of ICP and CBFV signals collected from 60 patients with different diagnoses. The results reveal that the ICP pulse leads CBFV for 90% of the patients regardless of the diagnosis and mean ICP value. In addition, we show that CBFV pulse onset latency is roughly determined by the distance of the measurement point to the heart. We conclude that the ICP signal is not generated as a standing wave and that ICP pulse onset may be related to the arteries proximal to the heart.

  19. Clinical Analysis of Giant Intracranial Aneurysms with Endovascular Embolization

    PubMed Central

    Ha, Sang Woo

    2012-01-01

    Objective The purpose of this study was to perform a clinical analysis of nine patients with giant aneurysms managed with endovascular embolization. Methods From March 2000 to September 2009, nine cases of giant intracranial aneurysms were treated (five unruptured and four ruptured). The nine patients included two males and seven females who were 47 to 72 years old (mean, 59.2 years old). The types of giant intracranial aneurysms were eight internal carotid artery aneurysms and one vertebral artery aneurysm. Treatment for each aneurysm was chosen based on anatomic relationships, aneurysmal factors, and the patients' clinical state. Three patients underwent endovascular coiling with stent and six initially underwent endovascular coiling alone. Medical records, operation records, postoperative angiographies, and follow-up angiographies were reviewed retrospectively. Results Eight out of nine patients showed good clinical outcomes. (six were excellent and two were good) after a mean follow-up period of 27.9 months. Six (67%) of the nine patients had a near-complete occlusions on the post-operative angiogram (mean, 13.5 months after the procedure). Occlusion rates of 90% or higher were obtained for eight (89%) of all the patients. One patient died due to multiple organ failure. Stents were ultimately required at some point for managing four aneurysms. Two patients needed additional procedures because of aneurysm regrowth. Conclusion Endovascular treatment could be an alternative option for managing giant aneurysms adjuvant to surgical intervention. PMID:23210026

  20. Intracranial Aneurysms: Review of Current Treatment Options and Outcomes

    PubMed Central

    Seibert, Brad; Tummala, Ramachandra P.; Chow, Ricky; Faridar, Alireza; Mousavi, Seyed A.; Divani, Afshin A.

    2011-01-01

    Intracranial aneurysms are present in roughly 5% of the population, yet most are often asymptomatic and never detected. Development of an aneurysm typically occurs during adulthood, while formation and growth are associated with risk factors such as age, hypertension, pre-existing familial conditions, and smoking. Subarachnoid hemorrhage, the most common presentation due to aneurysm rupture, represents a serious medical condition often leading to severe neurological deficit or death. Recent technological advances in imaging modalities, along with increased understanding of natural history and prevalence of aneurysms, have increased detection of asymptomatic unruptured intracranial aneurysms (UIA). Studies reporting on the risk of rupture and outcomes have provided much insight, but the debate remains of how and when unruptured aneurysms should be managed. Treatment methods include two major intervention options: clipping of the aneurysm and endovascular methods such as coiling, stent-assisted coiling, and flow diversion stents. The studies reviewed here support the generalized notion that endovascular treatment of UIA provides a safe and effective alternative to surgical treatment. The risks associated with endovascular repair are lower and incur shorter hospital stays for appropriately selected patients. The endovascular treatment option should be considered based on factors such as aneurysm size, location, patient medical history, and operator experience. PMID:21779274

  1. Intracranial Cortical Calcifications in a Focal Epilepsy Patient with Pseudohypoparathyroidism.

    PubMed

    Kim, Ye Sel; Park, Jihyung; Park, Yoonkyung; Hwang, KyoungJin; Koo, Dae Lim; Kim, Daeyoung; Seo, Dae-Won

    2016-06-01

    Patients with chronic parathyroid dysfunction often have intracranial calcification in deep gray matter (GM) and subcortical white matter (WM) of their brain. Some of them are also epilepsy patients. Although cortical etiologies are main cause of epileptic seizure, cortical calcification has not been reported in these patients. We report a newly diagnosed focal epilepsy patient whose brain magnetic resonance imaging revealed intracranial calcifications in cortical as well as subcortical areas. Blood lab revealed that he had hypocalcemia due to pseudohypoparathyroidism. Video EEG monitoring revealed the ictal EEG mainly consist of polymorphic delta to theta waves with maximum at right temporal area followed by background attenuation and muscle artifacts. The interictal EEG showed multiple focal spike-wave discharges. After given oral calcium and calcitriol supplement, his calcium and phosphorous level normalized and he remains seizure free. This is the first case to show cortical calcification in a patient with pseudohypoparathyroidism. Cortical calcification could be an important measure of seizure burden in these patients and thus sophisticated imaging protocols should be used to visualize the extent of calcium deposits. PMID:27390678

  2. Reconfigurable Polymer Networks for Improved Treatment of Intracranial Aneurysms

    NASA Astrophysics Data System (ADS)

    Ninh, Chi Suze Q.

    Endovascular embolization of intracranial aneurysms is a minimally invasive treatment in which an implanted material forms a clot to isolate the weakened vessel. Current strategy suffers from long-term potential failure modes. These potential failure modes include (1) enzymatic degradation of the fibrin clot that leads to compaction of the embolic agent, (2) incomplete filling of the aneurysm sac by embolic agent, and (3) challenging geometry of wide neck aneurysms. In the case of wide neck aneurysms, usually an assisting metal stent is used to help open the artery. However, metal stents with much higher modulus in comparison to the soft blood vessel can cause biocompatibilities issues in the long term such as infection and scarring. Motivated to solve these challenges associated with endovascular embolization, strategies to synthesize and engineer reconfigurable and biodegradable polymers as alternative therapies are evaluated in this thesis. (1) Reconfiguration of fibrin gel's modulus was achieved through crosslinking with genipin released from a biodegradable polymer matrix. (2) Reconfigurability can also be achieved by transforming triblock co-polymer hydrogel into photoresponsive material through incorporation of melanin nanoparticles as efficient photosensitizers. (3) Finally, reconfigurability can be conferred on biodegradable polyester networks via Diels-Alder coupling of furan pendant groups and dimaleimide crosslinking agent. Taken all together, this thesis describes strategies to transform a broad class of polymer networks into reconfigurable materials for improved treatment of intracranial aneurysms as well as for other biomedical applications.

  3. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement

    PubMed Central

    Hussain, Ahmad S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates.

  4. Intracranial Cortical Calcifications in a Focal Epilepsy Patient with Pseudohypoparathyroidism

    PubMed Central

    Kim, Ye Sel; Park, Jihyung; Park, Yoonkyung; Hwang, KyoungJin; Koo, Dae Lim; Kim, Daeyoung; Seo, Dae-Won

    2016-01-01

    Patients with chronic parathyroid dysfunction often have intracranial calcification in deep gray matter (GM) and subcortical white matter (WM) of their brain. Some of them are also epilepsy patients. Although cortical etiologies are main cause of epileptic seizure, cortical calcification has not been reported in these patients. We report a newly diagnosed focal epilepsy patient whose brain magnetic resonance imaging revealed intracranial calcifications in cortical as well as subcortical areas. Blood lab revealed that he had hypocalcemia due to pseudohypoparathyroidism. Video EEG monitoring revealed the ictal EEG mainly consist of polymorphic delta to theta waves with maximum at right temporal area followed by background attenuation and muscle artifacts. The interictal EEG showed multiple focal spike-wave discharges. After given oral calcium and calcitriol supplement, his calcium and phosphorous level normalized and he remains seizure free. This is the first case to show cortical calcification in a patient with pseudohypoparathyroidism. Cortical calcification could be an important measure of seizure burden in these patients and thus sophisticated imaging protocols should be used to visualize the extent of calcium deposits. PMID:27390678

  5. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement.

    PubMed

    Hussain, Ahmad S; Hussain, Namath S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates. PMID:27672529

  6. Method and Apparatus for Assessment of Changes in Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    A non-invasive method and apparatus for monitoring changes in intracranial pressure which removes extracranial effects from the measurements. The method and apparatus can include the supplying of a fixed frequency electrical output to a transducer coupled to the patient's head, thereby generating an acoustical tone burst in the patient's head which generates a first echo and a second echo, the first echo reflecting from a first interface in the side of the patient's head coupled to the transducer, and the second echo reflecting from a second interface at the opposite side of the patient's head. The first and second echoes are received by the transducer which can generate a first electrical signal and a second electrical signal, wherein the first and second electrical signals vary in accordance with the corresponding first and second echoes. The counterbalancing phase shifts required to bring about quadrature between each of the first and second electrical signals and the fixed frequency electrical output can be measured, and values for the change in intracranial distance based on the changes in the counterbalancing phase shifts can be obtained.

  7. Organic electronics based pressure sensor towards intracranial pressure monitoring

    NASA Astrophysics Data System (ADS)

    Rai, Pratyush; Varadan, Vijay K.

    2010-04-01

    The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

  8. Study and Therapeutic Progress on Intracranial Serpentine Aneurysms

    PubMed Central

    Xu, Kan; Yu, Tiecheng; Guo, Yunbao; Yu, Jinlu

    2016-01-01

    An intracranial serpentine aneurysm (SA) is a clinically rare entity, and very few multi-case studies on SA have been published. The present study reviewed the relevant literature available on PubMed. The studied information included the formation mechanism and natural history of SA as well as its clinical manifestation, imaging characteristics, and current treatments. After reviewing the literature, we conclude that intracranial SA can be managed surgically and by endovascular embolization, but the degree of blood flow in normal brain tissue distal to the SA must be evaluated. A balloon occlusion test (BOT) or cross compression test is recommended for this evaluation. If the collateral circulation is sufficiently compensatory, direct excision or embolization can be performed. However, if the compensatory collateral circulation is poor, a bypass surgery is necessary. Satisfactory results can be achieved in the majority of SA patients after treatment. However, the size of the aneurysm may increase in some patients after endovascular treatment. Special attention should be paid to cases exhibiting a significant mass effect to avoid subsequent SA excision due to an intolerable mass effect. Satisfactory results can be achieved with careful treatment of SA. PMID:27279792

  9. Delayed intracranial hematoma following stereoelectroencephalography for intractable epilepsy: case report.

    PubMed

    Derrey, Stéphane; Lebas, Axel; Parain, Dominique; Baray, Marie Gilles; Marguet, Christophe; Freger, Pierre; Proust, François

    2012-12-01

    Intracranial bleeding following stereoelectroencephalography (sEEG) is rare and commonly occurs early after electrode implantation. The authors report the case of a delayed intracranial hematoma following sEEG. This 10-year-old boy was referred to the authors' department to undergo an sEEG study for intractable epilepsy, with the hypothesis of a single localized epileptic zone in the left precentral region. To perform the exploration, 14 depth electrodes were implanted under stereotactic conditions. The results of a postoperative CT scan performed routinely at the end of the surgical procedure were normal. Eight days later, following an epileptic seizure, the child's condition worsened. The neurological examination revealed a left hemiparesis, agitation, and coma due to a right subdural hematoma with intraparenchymal bleeding. Despite a surgical evacuation followed by a decompressive craniectomy, the curative treatments were stopped 1 week later due to severe diffuse ischemic lesions found on MRI studies. This is the first observation of a delayed hematoma following an sEEG procedure. The mechanism underlying this complication remains unclear, but the rupture of a growing pseudoaneurysm caused by the electrode's implantation or the tearing of a neighboring vessel by an electrode were suspected. In consequence, physicians must remain vigilant during the entire sEEG recording period and probably also several days after electrode removal.

  10. Visual Impairment/Increased Intracranial Pressure (VIIP): Layman's Summary

    NASA Technical Reports Server (NTRS)

    Fogarty, Jennifer

    2011-01-01

    To date NASA has documented that seven long duration astronauts have experienced in-flight and post-flight changes in vision and eye anatomy including degraded distant vision, swelling of the back of the eye, and changes in the shape of the globe. We have also documented in a few of these astronauts post-flight, increases in the pressure of the fluid that surrounds the brain and spinal cord. This is referred to as increased intracranial pressure (ICP). The functional and anatomical changes have varied in severity and duration. In the post-flight time period, some individuals have experienced a return to a pre-flight level of visual function while others have experienced changes that remain significantly altered compared to pre-flight. In addition, the increased ICP also persists in the post-flight time period. Currently, the underlying cause or causes of these changes is/are unknown but the spaceflight community at NASA suspects that the shift of blood toward the head and the changes in physiology that accompany it, such as increased intracranial pressure, play a significant role.

  11. Intracranial injection of adeno-associated viral vectors.

    PubMed

    Lowery, Rebecca L; Majewska, Ania K

    2010-01-01

    Intracranial injection of viral vectors engineered to express a fluorescent protein is a versatile labeling technique for visualization of specific subsets of cells in different brain regions both in vivo and in brain sections. Unlike the injection of fluorescent dyes, viral labeling offers targeting of individual cell types and is less expensive and time consuming than establishing transgenic mouse lines. In this technique, an adeno-associated viral (AAV) vector is injected intracranially using stereotaxic coordinates, a micropipette and an automated pump for precise delivery of AAV to the desired area with minimal damage to the surrounding tissue. Injection parameters can be tailored to individual experiments by adjusting the animal age at injection, injection location, volume of injection, rate of injection, AAV serotype and the promoter driving gene expression. Depending on the conditions chosen, virally-induced transgene expression can allow visualization of groups of cells, individual cells or fine cellular processes, down to the level of dendritic spines. The experiment shown here depicts an injection of double-stranded AAV expressing green fluorescent protein for the labeling of neurons and glia in the mouse primary visual cortex. PMID:21113119

  12. Histological and immunohistochemical studies on primary intracranial canine histiocytic sarcomas

    PubMed Central

    THONGTHARB, Atigan; UCHIDA, Kazuyuki; CHAMBERS, James Kenn; KAGAWA, Yumiko; NAKAYAMA, Hiroyuki

    2015-01-01

    Histiocytic sarcoma is a progressive and fatal malignant neoplasm that mainly occurs in middle- to old-aged dogs. This study describes clinicopathological, histological and immunohistochemical characteristics of intracranial histiocytic sarcomas in 23 dogs. Magnetic resonance imaging and/or computed tomography of the brains revealed that the tumors mainly located in the cerebrum, particularly the frontal lobe. Seizure was a predominant clinical sign in most of the cases. Histologically, the tumor cells were morphologically classified into round/polygonal- and spindle-shaped cell types. There was a significant association between tumor cell types and hemophagocytic activity (P<0.05). However, there was no significant difference in other clinicopathological parameters and mitotic index between the 2 types. Immunohistochemically, tumor cells were strongly positive for HLA-DR, Iba-1 and CD204 in all the 23 cases, for iNOS in 20, for CD163 in 17, for CD208 (DC-LAMP) in 9, for lysozyme in 8 and for S100 in 5 cases. In addition, the Ki67-proliferative index showed range of 0.50–64.33% (Average 26.60 ± 3.81%). These observations suggest that canine primary intracranial histiocytic sarcomas tend to exhibit both dendritic cell and macrophage phenotypes of histiocytic differentiation. PMID:26668164

  13. Saturn ring temperature variations with approaching ring equinox

    NASA Astrophysics Data System (ADS)

    Spilker, L.; Leyrat, C.; Flandes, A.; Altobelli, N.; Pilorz, S.; Ferrari, C.; Edgington, S.

    2009-04-01

    Cassini's Composite Infrared Spectrometer (CIRS) has acquired a wide-ranging set of thermal measurements of Saturn's main rings (A, B, C and Cassini Division) at solar elevations ranging from less than one degree to 24 degrees. At Saturn equinox in August the solar elevation angle will reach zero as the sun traverses from the south to north side of the rings. For the data acquired to date, temperatures were retrieved for the lit and unlit rings over a variety of ring geometries that include solar elevation, as well as spacecraft elevation, phase angle and local hour angle. To first order, the largest temperature changes on the lit face of the rings are driven by variations in phase angle while differences in temperature with changing spacecraft elevation and local time are a secondary effect. Decreasing ring temperature with decreasing solar elevation are observed for both the lit and unlit faces of the rings after phase angle and local time effects are taken into account. As the solar elevation continues to decrease, the ring temperatures are decreasing in a non-linear fashion. The difference in temperature between the lit and unlit sides of the rings is decreasing also with decreasing solar elevation. Using ring thermal models developed by Leyrat we extrapolate to the expected minimum ring temperatures at equinox for our planned CIRS ring observations. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and at CEA Saclay supported by the "Programme National de Planetologie". Copyright 2009 California Institute of Technology. Government sponsorship acknowledged.

  14. How does Saturn's moons influence the velocity dispersion in the A ring

    NASA Astrophysics Data System (ADS)

    Seiß, M.; Schmidt, J.; Spahn, F.

    2011-10-01

    Saturn's moons perturb the rings due to their gravitational interactions with the ring material. Here, we present a model which accounts for the heating of the ring material due to these perturbations. The results emphasize the importance of the moon Prometheus for the velocity dispersion in the outer A ring of Saturn, which is probably 10 times higher than in the innermost A ring. An enhanced velocity dispersion would in turn lead to an enhanced production of smaller debris particles by knocking them off from larger parent bodies. This could lead to an increasing optical depth and brightness and limit the observability of the selfgravity wakes in the outer A ring. Furthermore, the velocity dispersion can be strongly enhanced in the vicinity of the major resonances (e.g. Janus 5:4) explaining the observed halos around them.

  15. DEPRESSED CELL-MEDIATED IMMUNITY IN PATIENTS WITH PRIMARY INTRACRANIAL TUMORS

    PubMed Central

    Brooks, William H.; Netsky, Martin G.; Normansell, David E.; Horwitz, David A.

    1972-01-01

    Tumor immunity in patients with primary intracranial tumors was assessed in relation to the general status of host immunocompetence. Lymphocyte sensitization to tumor-specific membrane antigens was demonstrated by the proliferative response of lymphocytes in the presence of autochthonous tumor cells. Paradoxically, one-half of the patients could not be sensitized to a primary antigen, dinitrochlorobenzene; existing delayed hypersensitivity was also depressed, as measured by skin tests and lymphocyte transformation in response to common antigens. A heat-stable factor in patients' sera blocked cell-mediated tumor immunity. In addition, these "enhancing" sera consistently suppressed the blastogenic response of autologous and homologous lymphocytes to phytohemagglutinin and to membrane antigens on allogeneic cells in the one-way mixed lymphocyte culture. When patients' leukocytes were washed and autologous plasma replaced with normal plasma, reactivity in the mixed lymphocyte culture increased to normal values. In vitro immunosuppressive activity in patients' plasma or sera correlated with depressed delayed hypersensitivity. After removal of the tumor, suppressor activity disappeared. IgG fractions of patient sera contained strong immunosuppressive activity. These data suggest that the suppressor factor may be an isoantibody elicited by the tumor that also binds to receptors on the lymphocyte membrane. In addition to specifically blocking cell-mediated tumor immunity, enhancing sera may broadly depress host immunocompetence. PMID:4345108

  16. Improving visualization of intracranial arteries at the skull base for CT angiography with calcified plaques

    NASA Astrophysics Data System (ADS)

    Huang, Adam; Lee, Chung-Wei; Yang, Chung-Yi; Liu, Hon-Man

    2010-03-01

    Bony structures at the skull base were the main obstacle to detection and estimation of arterial stenoses and aneurysms for CT angiography in the brain. Direct subtraction and the matched mask bone elimination (MMBE) have become two standard methods for removing bony structures. However, clinicians regularly find that calcified plaques at or near the carotid canal cannot be removed satisfactorily by existing methods. The blood-plaque boundary tends to be blurred by subtraction operation while plaque size is constantly overestimated by the bone mask dilation operation in the MMBE approach. In this study, we propose using the level of enhancement to adjust the MMBE bone mask more intelligently on the artery- and tissue-bone/plaque boundaries. The original MMBE method is only applied to the tissue-bone boundary voxels; while the artery-bone/blood-plaque boundary voxels, identified by a higher enhancement level, are processed by direct subtraction instead. A dataset of 6 patients (3 scanned with a regular dose and 3 scanned with a reduced dose) with calcified plaques at or near the skull base is used to examine our new method. Preliminary results indicate that the visualization of intracranial arteries with calcified plaques at the skull base can be improved effectively and efficiently.

  17. Ring Image Analyzer

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry V.

    2012-01-01

    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  18. Pressure-Energized Seal Rings to Better Withstand Flows

    NASA Technical Reports Server (NTRS)

    Farner, Bruce

    2009-01-01

    Pressure-energized seal rings intended to withstand flows better than do conventional pressure-energized seal rings have been conceived. The concept applies, more specifically, to seal rings used on some valve stems, pistons, and the like. A conventional pressure-energized seal ring generally has a U-shaped cross section and consists of an elastomer or other suitable polymer with an embedded metal energizing spring (see Figure 1). The working fluid from the high-pressure side that one seeks to seal is allowed into the U-shaped cavity, so that the pressure pushes the sides of the seal ring tighter against the gland and body sealing surfaces, thereby increasing the degree of sealing. Unfortunately, when the seal ring is exposed to flow of the working fluid, under some conditions, the flow grabs the lip of the U-shaped cross section and ejects or deforms the seal ring so that, thereafter, a proper seal is not obtained. Figure 2 depicts one of several alternative seal rings according to the present concept. One element of the concept is to modify the U-shaped cross section from that of the corresponding conventional seal ring to eliminate the exposed lip and prevent entry of the working fluid into the U-shaped cavity. Unlike in the conventional seal, pressurized fluid would not push the seal ring directly against the both gland and body sealing surfaces. Instead, the pressure would directly push the seal ring against a gland sealing surface only. In so doing, the pressure would squash the seal ring into a smaller volume bounded by the gland and body sealing surfaces, and would thereby indirectly press the seal ring more tightly against the body sealing surface. To enhance the desired squashing deformation, a spring having an approximately parallelogram cross section would be embedded in the modified U-shaped cavity. As the pressure pushed two corners of the approximate parallelogram closer together along the axis of the seal ring, the other two corners of the

  19. Multiple myeloma with intracranial extension and bilateral renal infiltration: A case report and review of the literature

    PubMed Central

    ZHANG, MIN-JUAN; SU, GUO-HONG; SHEN, JIE; LIU, FENG-HAI; XU, YAN-FENG; ZHANG, XIAO-LING; WANG, QING; WANG, RUI-HUAN; LIU, CHUN-YAN; ZHAO, YU-LEI

    2015-01-01

    Multiple myeloma (MM) is a rare hematological malignancy, characterized by uncontrolled proliferation of plasma cells in the bone marrow. MM is usually confined to the bone marrow, however, it may occasionally infiltrate other tissues, which is known as extramedullary plasmacytoma (EMP). The majority of EMPs involve the head and neck region, although different anatomical sites, including the gastrointestinal tract, central nervous system, thyroid gland and breast may also be affected. The simultaneous presentation of EMP in the kidney and head is rare, presenting diagnostic challenges due to its unusual location and non-specific or absent symptoms. To the best of our knowledge, no case of extramedullary plasmacytoma presenting with simultaneous renal and intracranial infiltration has been reported in the literature thus far. However, the present study reports a case of primary renal and intracranial extramedullary plasmacytoma in a 76-year-old male patient. The patient presented with a swelling over the right side of the forehead, which had slowly increased in size prior to hospital admission. The swelling was associated with dizziness and weakness, without bone pain. Contrast magnetic resonance imaging suggested an osteolytic skull lesion with intracranial extension. Abdominal enhanced computed tomography scanning revealed a large tumor mass extending around and into the kidneys. Immunohistochemical examination of the renal tumor biopsy, and blood and serum samples, as well as immunoelectrophoresis of serum proteins, resulted in a diagnosis of EMP being proposed. Therefore, the patient was administered with two cycles of cyclophosphamide and thalidomide in combination with dexamethasone. Follow-up imaging performed 4 months later revealed almost complete disappearance of the intracranial tumor mass and renal infiltration. The current study also presented a review of the literature. This study revealed that EMPs may co-exist with MM or present as the main symptom

  20. Predictive optimization of piston and ring stability

    SciTech Connect

    Knowland, C.G.; Russell, C.J.

    1996-09-01

    A fundamental aspect of the engine development process involves the determination of acceptable piston and ring profiles. There exists a fine balance between the requirements of the piston skirt or ring profile to resist scuffing together with the overall product objectives of reduced oil consumption, blow-by and engine noise. Taking into account these varying and often conflicting considerations, in addition to the time and cost implications of repetitive development testing, drives them towards the necessity for some form of predictive optimization scheme. Benefits from the application of such a predictive tool include: development of piston skirt profiles for adequate running clearance under operating conditions; optimization of piston stability as a function of such parameters as piston pin offset; enhanced bore reaction forces for improved NVH predictions; reduced levels of blow-by and improved oil control.