Sample records for intraconal orbital cavernous

  1. Cavernous hemangioma of the orbit: an unusual acute presentation

    PubMed Central

    Louisraj, Sophia; Ponnudurai, Thendral; Rodriguez, Dominic; Thomas, Philip A; Nelson Jesudasan, Christadoss Arul

    2017-01-01

    We report an unusual presentation of an orbital cavernous hemangioma in a 26-year-old female, who noted sudden redness and swelling of the left eye (LE) on waking up. At presentation, upper eyelid edema with periorbital ecchymosis and subconjunctival hemorrhage were noted in the LE. Although there was transient symptomatic relief with topical medications, blurring of vision developed in the LE. When seen 10 days later, the patient’s LE showed axial proptosis. Magnetic resonance imaging revealed an intraconal soft tissue mass in the superomedial quadrant of the left orbit. Superior orbitotomy with mass excision was done; histopathological examination of the excised mass revealed a cavernous hemangioma. The patient had complete visual recovery following surgery. To our knowledge, an acute presentation of an orbital cavernous hemangioma with subconjunctival hemorrhage and periorbital ecchymosis has not previously been reported. PMID:28769595

  2. The anatomical location and laterality of orbital cavernous haemangiomas.

    PubMed

    McNab, Alan A; Selva, Dinesh; Hardy, Thomas G; O'Donnell, Brett

    2014-10-01

    To determine the anatomical location and laterality of orbital cavernous haemangiomas (OCH). Retrospective case series. The records of 104 patients with OCH were analyzed. The anatomical location of each OCH defined by the location of a point at the centre of the lesion, and its laterality. There were 104 patients included in the study. No patient had more than one lesion. Sixteen (15.4%) were located in the anterior third of the orbit, 74 (71.2%) were in the middle third, and 14 (13.5%) in the posterior third. In the middle third, 10 of 74 (13.5%) were extraconal and 64 intraconal (86.5%), with 30 of 64 (46.9%) middle third intraconal lesions lying lateral to the optic nerve. Of 104 lesions, 56 (53.8%) were left sided, showing a trend towards a predilection for the left side (p = 0.065). If data from other published series which included data on laterality is added to our own data and analysed, 270 of 468 (57.7%) OCH occurred in the left orbit (p < 0.005). OCH may occur at almost any location within the orbit. The commonest location is the middle third of the orbit, in the intraconal space lateral to the optic nerve. This may reflect an origin of these lesions from the arterial side of the circulation, as there are more small arteries in the intraconal space lateral to the optic nerve than in other locations. A predilection for the left orbit remains unexplained.

  3. Unusual intraconal localization of orbital giant cell angiofibroma.

    PubMed

    Ekin, Meryem Altin; Ugurlu, Seyda Karadeniz; Cakalagaoglu, Fulya

    2018-01-01

    Giant cell angiofibroma (GCA) is a recently reported rare soft-tissue tumor that can develop in various sites including orbit. Orbital GCAs were mainly located in the eyelid or extraconal regions such as lacrimal gland and conjunctiva. We report an atypical case of a GCA arising in the intraconal area of the orbit in a 65-year-old male patient. The tumor was excised in total by lateral orbitotomy. Histological and immunohistochemical features were consistent with the diagnosis of GCA. No recurrence was observed during the follow-up of over 2 years. GCA is a rare tumor that should be considered in the differential diagnosis of intraconal orbital tumors. Complete surgical removal is the current optimal treatment option.

  4. Unusual intraconal localization of orbital giant cell angiofibroma

    PubMed Central

    Ekin, Meryem Altin; Ugurlu, Seyda Karadeniz; Cakalagaoglu, Fulya

    2018-01-01

    Giant cell angiofibroma (GCA) is a recently reported rare soft-tissue tumor that can develop in various sites including orbit. Orbital GCAs were mainly located in the eyelid or extraconal regions such as lacrimal gland and conjunctiva. We report an atypical case of a GCA arising in the intraconal area of the orbit in a 65-year-old male patient. The tumor was excised in total by lateral orbitotomy. Histological and immunohistochemical features were consistent with the diagnosis of GCA. No recurrence was observed during the follow-up of over 2 years. GCA is a rare tumor that should be considered in the differential diagnosis of intraconal orbital tumors. Complete surgical removal is the current optimal treatment option. PMID:29283151

  5. Removal of an orbital apex hemangioma using an endoscopic transethmoidal approach: technical note.

    PubMed

    Karaki, Masayuki; Kobayashi, Ryuichi; Mori, Nozomu

    2006-07-01

    The posterior orbit contains a number of important and vulnerable structures, including the optic nerve, the ophthalmic artery and vein, and the ocular muscles and their motor nerves, which makes surgical access to the lesion in this region quite difficult. Transfrontal, transfrontal-ethmoidal, and transmaxillary procedures have the disadvantage of possible injuries to a number of nontumor structures, whereas an endoscopic transethmoidal approach is a minimally invasive surgery for the retrobulbar lesions. Retrobulbar cavernous hemangioma was successfully removed by a transethmoidal approach. Tumor removal was performed in a patient with an intraconal cavernous hemangioma of approximately 15 mm in diameter. By a transethmoidal approach, the medial-inferior part of the orbit, as well as the apex of the orbit, were clearly visualized after endonasal ethmoidectomy. After the removal of the medial orbital bone, the orbital periosteum was incised and elevated. By elevating the orbital fat, the tumor could be identified separately from the orbital contents. Cavernous hemangioma at the orbital apex was removed without complications. An endoscopic transethmoidal approach, which requires no skin incision, is a minimally invasive surgery for retrobulbar orbital tumor, leading to excellent cosmetic results with less bleeding.

  6. Comparative techniques of medial rectus muscle retraction for endoscopic exposure of the medial intraconal space.

    PubMed

    Lin, Giant C; Freitag, Suzanne K; Kocharyan, Armine; Yoon, Michael K; Lefebvre, Daniel R; Bleier, Benjamin S

    2016-05-01

    The medial rectus muscle (MRM) is the medial boundary to the intraconal space of the orbit, and retraction of the MRM is oftentimes necessary for endoscopic removal of intraconal tumors, e.g., orbital hemangioma. We evaluated each of the reported methods of MRM retraction for endoscopic orbital surgery and quantified the degree of intraconal exposure conferred by each method. Eight orbits from four cadaver heads were dissected. In each orbit, medial orbital decompression was performed and the MRM was retracted by using four previously described techniques: (1) external MRM retraction at the globe insertion point by using vessel loop (external group), (2) transseptal MRM retraction by using vessel loop (transseptal group), (3) transchoanal retraction of the MRM by using vessel loop (choanal group), and (4) transseptal four-handed technique by using double ball retraction by a second surgeon (transseptal double ball group). The length, height, and area of exposure of the medial intraconal space were quantified and compared. The average ± standard deviation (SD) anterior-posterior exposures for the external group, transseptal group, and transseptal double ball group were 17.51 ± 3.39 mm, 16.59 ± 4.16 mm, and 18.0 ± 15.25 mm, respectively. The choanal group provided significantly less exposure (12.39 ± 3.44 mm, p = 0.049) than the other groups. The average ± SD vertical exposures for the transseptal group, choanal group, and transseptal double ball group were 12.53 ± 4.38 mm, 13.05 ± 5.86 mm, and 13.57 ± 3.74 mm, respectively. The external group provided significantly less exposure (4.51 ± 1.56 mm, p = 0.0072) than the other groups. The transseptal and transseptal double ball groups provided the greatest total access by surface area (58.88 ± 26.96 mm(2) and 62.94 ± 34.74 mm(2), respectively) compared with the external and choanal groups (34.82 ± 23.37 mm(2) and 43.10 ± 23.68 mm(2), respectively). Although the transseptal trajectory of MRM retraction was

  7. Preoperative diagnosis of orbital cavernous hemangioma: a 99mTc-RBC SPECT study.

    PubMed

    Burroni, Luca; Borsari, Giulia; Pichierri, Patrizia; Polito, Ennio; Toscano, Olga; Grassetto, Gaia; Al-Nahhas, Adil; Rubello, Domenico; Vattimo, Angelo Giuseppe

    2012-11-01

    This study aimed to describe 99mTc-labeled RBC scintigraphy as a diagnostic method for orbital cavernous hemangiomas and to evaluate this diagnostic tool according to surgical outcomes. Fifty-five patients with clinical and radiological (US, CT, and/or MRI) suspicion of unilateral cavernous hemangioma of the orbit underwent 99mTc-RBC SPECT study.Qualitative and semiquantitative evaluations were performed, and results were statistically analyzed. SPECT images showed focal uptake in the orbital mass in 36 of 55 patients. Nineteen patients had a negative scintigraphic pattern, with concordance of early and late absence of uptake of 99mTc-RBC.Our procedure showed 100% sensitivity and 88.9% specificity for the diagnosis of orbital cavernous hemangioma, with a positive predictive value of 90.9% and a negative predictive value of 100%. 99mTc-RBC imaging is safe, easy to perform, and highly accurate in providing adequate clinical and surgical management. As a noninvasive and highly specific method for diagnosing orbital hemangioma, 99mTc-RBC scintigraphy can avoid more invasive imaging or biopsy.

  8. In Vivo Effects of Retrobulbar Bimatoprost Injection on Orbital Fat.

    PubMed

    Eftekhari, Kian; Vagefi, M Reza; Lee, Vivian; Hui, James Z; Zhu, Menglong; Dine, Kimberly; Anderson, Richard L; Koeberlein, Brigitte; Sulaimankutty, Reas; Shindler, Kenneth S

    Recent publications have reported the adverse effects of prostaglandin analogues on the periocular tissues. These medications may cause periorbital lipodystrophy, enophthalmos, and deepening of the superior sulcus deformity. While these effects may have adverse consequences for some patients, the atrophy of the periorbital fat may have a useful role in diseases that lead to orbital and periorbital fat hypertrophy such as thyroid eye disease. In this pilot study, the authors investigated the effects of retrobulbar bimatoprost injection on the intraocular pressure and orbital fat in a rat animal model. Three rats were sedated and intraocular pressure was measured. A 0.1 ml aliquot of bimatoprost was injected into the right orbit of all rats. In the left orbit, 0.1 ml of phosphate-buffered saline was injected as a control. Three weeks later, all rats were sedated and intraocular pressure was measured before euthanizing. Routine histologic staining was performed and thin sections through the intraconal orbital fat were obtained. Density of intraconal adipocytes was measured and adipocyte heterogeneity was determined using a computer image analysis algorithm. The specimens injected with bimatoprost demonstrated atrophy of orbital fat with significantly increased adipocyte density (p = 0.009) and heterogeneity (p = 0.008) when compared with control. Intraocular pressure was not significantly decreased at 3 weeks after injection of retrobulbar bimatoprost. In this pilot study, orbital injection of bimatoprost demonstrated atrophy of intraconal adipocytes when compared with control orbits injected with saline. The orbits injected with bimatoprost were noted to have smaller, more heterogeneous adipocytes that were densely packed in the intraconal space. The study limitations include the small sample size, which limited the ability for us to make conclusions about the effect on intraocular pressure. Nevertheless, the findings presented suggest that retrobulbar

  9. Technetium tc 99m-labeled red blood cells in the preoperative diagnosis of cavernous hemangioma and other vascular orbital tumors.

    PubMed

    Polito, Ennio; Burroni, Luca; Pichierri, Patrizia; Loffredo, Antonio; Vattimo, Angelo G

    2005-12-01

    To evaluate technetium Tc 99m (99mTc) red blood cell scintigraphy as a diagnostic tool for orbital cavernous hemangioma and to differentiate between orbital masses on the basis of their vascularization. We performed 99mTc red blood cell scintigraphy on 23 patients (8 female and 15 male; mean age, 47 years) affected by an orbital mass previously revealed with computed tomography (CT) and magnetic resonance imaging (MRI) and suggesting cavernous hemangioma. In our diagnosis, we considered the orbital increase delayed uptake with the typical scintigraphic pattern known as perfusion blood pool mismatch. The patients underwent biopsy or surgical treatment with transconjunctival cryosurgical extraction when possible. Single-photon emission tomography (SPET) showed intense focal uptake in the orbit corresponding to radiologic findings in 11 patients who underwent surgical treatment and pathologic evaluation (9 cavernous hemangiomas, 1 hemangiopericytoma, and 1 lymphangioma). Clinical or histologic examination of the remaining 22 patients revealed the presence of 5 lymphoid pseudotumors, 2 lymphomas, 2 pleomorphic adenomas of the lacrimal gland, 1 astrocytoma, 1 ophthalmic vein thrombosis, and 1 orbital varix. The confirmation of the preoperative diagnosis by 99mTc red blood cell scintigraphy shows that this technique is a reliable tool for differentiating cavernous hemangiomas from other orbital masses (sensitivity, 100%; specificity, 86%) when ultrasound, CT, and MRI are not diagnostic. Unfortunately, 99mTc red blood cell scintigraphy results were positive in 1 patient with hemangiopericytoma and 1 patient with lymphangioma, which showed increased uptake in the lesion on SPET images because of the vascular nature of these tumors. Therefore, in these cases, the SPET images have to be integrated with data regarding clinical preoperative evaluation and CT scans or MRI studies. On the basis of our study, a complete diagnostic picture, CT scans or MRI studies, and

  10. Spontaneous dural cavernous fistula in infancy.

    PubMed

    Johnson, Paul B; Lelli, Gary J; Khorsandi, Azita; Dellarocca, David A

    2010-01-01

    A 4-month-old boy presented with the sudden onset of proptosis and dilated episcleral veins. CT revealed an enlarged superior ophthalmic vein and diffusely thickened extraocular muscles. MRI and angiography confirmed a dural middle meningeal--cavernous sinus fistula. Embolization was performed leading to successful resolution of the patient's signs and symptoms. Spontaneous atraumatic arteriovenous cavernous fistulae in infancy are extremely rare, but should be included in the differential diagnosis of infants with orbital congestion. Appropriate treatment leads to prevention of amblyopia, glaucoma, and anisometropia.

  11. Management of Orbital Diseases.

    PubMed

    Betbeze, Caroline

    2015-09-01

    Orbital diseases are common in dogs and cats and can present on emergency due to the acute onset of many of these issues. The difficulty with diagnosis and therapy of orbital disease is that the location of the problem is not readily visible. The focus of this article is on recognizing classical clinical presentations of orbital disease, which are typically exophthalmos, strabismus, enophthalmos, proptosis, or intraconal swelling. After the orbital disease is confirmed, certain characteristics such as pain on opening the mouth, acute vs. chronic swelling, and involvement of nearby structures can be helpful in determining the underlying cause. Abscesses, cellulitis, sialoceles, neoplasia (primary or secondary), foreign bodies, and immune-mediated diseases can all lead to exophthalmos, but it can be difficult to determine the cause of disease without advanced diagnostic imaging, such as ultrasound, magnetic resonance imaging, or computed tomography scan. Fine-needle aspirates and biopsies of the retrobulbar space can also be performed. Published by Elsevier Inc.

  12. Limestone Caverns

    ERIC Educational Resources Information Center

    Powell, Richard L.

    1970-01-01

    Describes the origin of limestone caverns, using Mammoth Cave as an example, with particular reference to the importance of groundwater information of caverns, the present condition of groundwater, and how caverns develop within fluctuating groundwater zones. (BR)

  13. Transvenous embolization in spontaneous direct carotid-cavernous fistula in childhood

    PubMed Central

    Mercado, Glenna B.; Irie, Keiko; Negoro, Makoto; Moriya, Shigeta; Tanaka, Teppei; Ohmura, Masahiro; Sadato, Akiyo; Hayakawa, Motuharu; Sano, Hirotoshi

    2011-01-01

    Carotid cavernous fistula (CCF) is an abnormal arteriovenous communication in the cavernous sinus. Direct CCF results from a tear in the intracavernous carotid artery. Typically, it has a high flow and usually presents with oculo-orbital venous congestive features such as exophthalmos, chemosis, and sometimes oculomotor or abducens cranial nerve palsy. Indirect CCF generally occurs spontaneously with subtle signs. We report a rare case of spontaneous direct CCF in childhood who did not have the usual history of craniofacial trauma or connective tissue disorder but presented with progressive chemosis and exophthalmos of the right eye. This report aims also to describe the safety and success of transvenous embolization with coils of the superior ophthalmic vein and cavernous sinus through the inferior petrosal sinus. PMID:22059104

  14. [Septic cavernous sinus thrombosis following ethmoiditis: a case report].

    PubMed

    Ben Abdallah Chabchoub, R; Kmiha, S; Turki, F; Trabelsi, L; Maalej, B; Ben Salah, M; Abdelhédi Gargouri, L; Boukédi, A; Ben Halima, N; Mahfoudh, A

    2014-01-01

    Acute ethmoiditis is a rare infection of ethmoidal cells. The pathognomonic sign is an edema of the internal corner of the eye. Imaging may be necessary to verify the absence of orbital or endocranial complications. Thrombophlebitis of the cavernous sinus is a serious complication of this infectious process. We report the case of an 11-year-old boy who presented with ethmoiditis complicated with thrombophlebitis of the cavernous sinus, with right hemiplegia and left Bell palsy sequelae. Early diagnosis of this disorder and urgent therapy are essential. Treatment is based on the antibiotic therapy. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  15. Orbital schwannomatosis in the absence of neurofibromatosis.

    PubMed

    Koktekir, Bengu Ekinci; Kim, H Jane; Geske, Mike; Bloomer, Michelle; Vagefi, Reza; Kersten, Robert C

    2014-11-01

    The aim of this study was to describe 3 cases of primary orbital schwannomatosis without associated systemic neurofibromatosis. This is a retrospective interventional study of 3 patients who presented with multiple, distinct masses in the orbit (n = 3) as well as in the hemiface (n = 1). The clinical presentation, imaging features, surgical procedures, and outcomes were defined. Two women and a man presented with of exophthalmos and diplopia. Pain was the most prominent complaint in 2 patients. None of the patients had associated systemic neurofibromatosis by history or examination. Radiologic evaluation with computed tomography or magnetic resonance imaging of orbit revealed multiple well-demarcated intraconal and extraconal masses. Masses were excised, and histopathology confirmed all masses to be schwannomas. Postoperative follow-up was uneventful with alleviation of primary complaints in all patients. Multiple orbital schwannomas (primary orbital schwannomatosis) may be observed in patients without systemic association of neurofibromatosis. Management includes surgical excision of the tumors to achieve relief from their mass effects.

  16. Dural cavernous sinus fistula: an unusual presentation.

    PubMed Central

    Procope, J. A.; Kidwell, E. D.; Copeland, R. A.; Perry, A. F.

    1994-01-01

    This article describes a 22-year-old man who presented to the Howard University Hospital emergency room with acute onset of swelling, proptosis, and decreased vision in the right eye preceded by 24 hours of nausea and vomiting. The patient's visual acuity was count fingers in the involved eye with marked proptosis and limitation of ocular motility. There was no history given of any ocular or head trauma. A computed tomography scan of the orbits showed diffuse symmetric enlargement of the extraocular muscles of the right eye, felt to be consistent with an orbital inflammatory pseudotumor. The patient was treated with intravenous steroids initially, then placed on oral prednisone. After minimal improvement on the steroids, a selective external carotid angiogram showed a moderate-sized dural cavernous sinus fistula. The patient underwent selective embolization of the fistula with rapid resolution of periorbital edema and proptosis. Visual acuity was stabilized at 20/200 in the right eye. The differential diagnosis and pathogenesis of carotid cavernous sinus fistulas and the likely pathogenesis of the fistula in this case are discussed. Images Figure 1 Figure 2 Figure 3 PMID:8046763

  17. Manufactured caverns in carbonate rock

    DOEpatents

    Bruce, David A.; Falta, Ronald W.; Castle, James W.; Murdoch, Lawrence C.

    2007-01-02

    Disclosed is a process for manufacturing underground caverns suitable in one embodiment for storage of large volumes of gaseous or liquid materials. The method is an acid dissolution process that can be utilized to form caverns in carbonate rock formations. The caverns can be used to store large quantities of materials near transportation facilities or destination markets. The caverns can be used for storage of materials including fossil fuels, such as natural gas, refined products formed from fossil fuels, or waste materials, such as hazardous waste materials. The caverns can also be utilized for applications involving human access such as recreation or research. The method can also be utilized to form calcium chloride as a by-product of the cavern formation process.

  18. Pythium Keratitis Leading to Fatal Cavernous Sinus Thrombophlebitis.

    PubMed

    Rathi, Anubha; Chakrabarti, Arunaloke; Agarwal, Tushar; Pushker, Neelam; Patil, Mukesh; Kamble, Hemant; Titiyal, Jeewan S; Mohan, Rishi; Kashyap, Seema; Sharma, Sanjay; Sen, Seema; Satpathy, Gita; Sharma, Namrata

    2018-04-01

    To report a case of Pythium insidiosum keratitis leading to fatal cavernous sinus thrombophlebitis. Case report. A 70-year-old man presented with excruciating pain, redness, and diminution of vision in his left eye for 2 weeks after washing his hair with tap water. A total corneal ulcer with surrounding infiltrates and associated corneal thinning was present. Corneal scraping revealed the presence of Gram-positive cocci. KOH wet mount and in vivo confocal microscopy revealed branching hyphae. Combined antibacterial and antifungal treatment was started, but 4 days later, the ulcer showed signs of worsening with perforation for which a large therapeutic penetrating keratoplasty was done. The host cornea showed branching septate hyphae on Sabarouds Dextrose Agar. Two weeks later, the patient developed left eye proptosis with associated extraocular movement restriction. Magnetic resonance imaging of the head and orbit revealed cavernous sinus thrombophlebitis. Lid sparing partial exenteration was performed. Polymerase chain reaction revealed P. insidiosum. The patient subsequently developed a cerebrovascular attack and died of its complications. Ocular pythiosis may lead to cavernous sinus thrombophlebitis and can even be life threatening. Timely diagnosis and early radical surgery are of value. A high index of suspicion must be kept for P. insidiosum in cases with suspected fungal etiology not responding to conventional treatment.

  19. Gamma Knife surgery in patients harboring orbital cavernous hemangiomas that were diagnosed on the basis of imaging findings.

    PubMed

    Liu, Xiaomin; Xu, Desheng; Zhang, Yipei; Liu, Dong; Song, Guoxiang

    2010-12-01

    This study was undertaken to evaluate clinical outcomes and tumor control in patients harboring orbital cavernous hemangiomas (OCHs) that had been diagnosed based on findings of imaging studies and treated by Gamma Knife surgery (GKS). Between 1995 and 2008, 23 patients harboring OCHs that had been diagnosed on the basis of imaging findings were treated using GKS; complete follow-up data are available in all cases. The median treatment volume was 1.5 cm³ (range 0.15-10.10 cm³), the median tumor margin dose was 15 Gy (range 12-20 Gy), and the median follow-up period was 12 months (range 6-120 months). A decrease in tumor size was found in 20 patients, and no tumor progression was observed after GKS. Eleven of 14 patients whose visual function had been adversely affected prior to treatment had improved visual acuity at the last assessment. Side effects of the procedure included orbital pain in 3 patients and chemosis in 2 patients. In this preliminary experience, GKS proved to be an effective treatment for OCHs diagnosed on the basis of imaging findings. Additional follow-up is necessary, and the long-term side effects of the procedure still need to be determined.

  20. Cavernous sinus syndrome in a Holstein bull.

    PubMed

    Jacob, Sarah I; Drees, Randi; Pinkerton, Marie E; Bentley, Ellison M; Peek, Simon F

    2015-03-01

    A 13-month-old Holstein bull was presented for right-sided exophthalmos. Ophthalmologic examination noted that the animal was visual in both eyes, but that the right pupil was persistently dilated and very sluggish to constrict when stimulated with a bright light and that normal ocular motility was absent. Fundic examination of the right eye was normal as was a complete ophthalmologic examination of the left eye. Radiographs at presentation did not reveal the presence of sinusitis or other skull abnormalities. Initial treatment comprised intravenous antibiotics and anti-inflammatories for orbital inflammation over a 14-day period. There was no perceptible change in the appearance or neuro-ophthalmologic examination of the right eye during hospitalization. The animal was discharged to the owner's care, but 3 weeks later was found recumbent with unilateral strabismus of the left eye and a fixed right pupil. Due to the inability to rise and rapid deterioration, humane euthanasia was performed, and a full postmortem examination, preceded by a MRI, was performed that identified abscesses extending bilaterally through the round foramina obliterating the cavernous sinus region, as well as abscessation of the right mandible, right trigeminal neuritis, right-sided sinusitis, and right-sided otitis media. Cavernous sinus syndrome should be considered in cattle with a combination of exophthalmos and neuro-ophthalmologic abnormalities involving cranial nerves III, IV, V, and VI, whose branches are located within the cavernous sinus. © 2013 American College of Veterinary Ophthalmologists.

  1. "Tepid" Geysers above salt caverns

    NASA Astrophysics Data System (ADS)

    Bérest, Pierre; Brouard, Benoît; Zakharov, Vassily

    2018-06-01

    The formation of a brine geyser erupting from the wellhead of a large underground salt cavern is described. In most cases, the brine outflow from an opened cavern is slow; it results from the cavern creep closure and the thermal expansion of the cavern brine. These two processes are smooth; however, the brine outflow often is bumpy, as it is modulated by atmospheric pressure variations that generate an elastic increase (or decrease) of both cavern and brine volumes. In addition, when the flow is fast enough, the brine thermodynamic behavior in the wellbore is adiabatic. The cold brine expelled from the cavern wellhead is substituted with warm brine entering the borehole bottom, resulting in a lighter brine column. The brine outflow increases. In some cases, the flow becomes so fast that inertia terms must be taken into account. A geyser forms, coming to an end when the pressure in the cavern has dropped sufficiently. A better picture is obtained when head losses are considered. A closed-form solution can be reached. This proves that two cases must be distinguished, depending on whether the cold brine initially contained in the wellbore is expelled fully or not. It can also be shown that geyser formation is a rare event, as it requires both that the wellbore be narrow and that the cavern be very compressible. This study stemmed from an actual example in which a geyser was observed. However, scarce information is available, making any definite interpretation difficult. xml:lang="fr"

  2. Orbital nerve seath myxoma with extraocular muscle involvement: a rare case.

    PubMed

    Rodríguez-Uña, Ignacio; Troyano-Rivas, Juan A; González-García, Cristina; Chícharo-de-Freitas, Reinaldo; Ortiz-Zapata, Juan J; Ortega-Medina, Luis; Toledano-Fernández, Nicolás; García-Feijoo, Julián

    2015-07-01

    A 66-year-old woman with breast cancer presented with a painless mass in the left orbit. MRI revealed a well-defined intraconal mass in the temporal quadrant of the orbit. Fifteen months later, a further MRI indicated the mass had grown, displacing the left optic nerve and making contact with the lateral rectus muscle, suggesting its possible intramuscular origin. Despite the clinical and radiological characteristics of the lesion and its slow growth, a PET/CT study was developed because of the history of malignant disease. No metabolic activity of the mass or malignant lesion in other locations was observed. After surgical excision, histopathological examination revealed an abundant myxoid matrix with few spindle-shaped cells and no signs of malignancy. The cells were immunopositive for CD34, positive for S-100 protein, and negative for EMA, actin, and CD57. A diagnosis was made of a nerve sheath myxoma. The orbital location of these tumors is extremely rare.

  3. Brainstem and cerebellar cavernous malformations.

    PubMed

    Atwal, Gursant S; Sarris, Christina E; Spetzler, Robert F

    2017-01-01

    Cavernous malformations are vascular lesions that occur throughout the central nervous system, most commonly in the supratentorial location, with brainstem and cerebellar cavernous malformations occurring more rarely. Cavernous malformations are associated with developmental venous anomalies that occur sporadically or in familial form. Patients with a cavernous malformation can present with headaches, seizures, sensorimotor disturbances, or focal neurologic deficits based on the anatomic location of the lesion. Patients with infratentorial lesions present more commonly with a focal neurologic deficit. Cavernous malformations are increasingly discovered incidentally due to the increasing use of magnetic resonance imaging. Understanding the natural history of these lesions is essential to their management. Observation and surgical resection are both reasonable options in the treatment of patients with these lesions. The clinical presentation of the patient, the location of the lesion, and the surgical risk assessment all play critical roles in management decision-making. © 2017 Elsevier B.V. All rights reserved.

  4. An interesting case of angiogenesis in cavernous hemangioma.

    PubMed

    Das, Dipankar; Bhattacharjee, Kasturi; Deka, Panna; Bhattacharjee, Harsha; Misra, Diva Kant; Koul, Akanksha; Kapoor, Deepika; Deka, Apurba

    2016-10-01

    Cavernous hemangioma is the most common orbital tumor in adult. There is lot of literatures for clinicopathological features of this tumor. These tumors had been studied for the model of angiogenesis in many of the experimental setups. We present a case of 34-year-old male with this tumor in the left eye with computerized tomography evidence. Postsurgical laboratory findings gave interesting evidence of tumor angiogenesis with tumor endothelial cells and sprouting of the small vessels endothelial cells. Podosome rosette could be conceptualized from the characteristic patterns seen in the tumor.

  5. Real-time evaluation of diffusion of the local anesthetic solution during peribulbar block using ultrasound imaging and clinical correlates of diffusion.

    PubMed

    Luyet, Cédric; Eng, Kenneth T; Kertes, Peter J; Avila, Arsenio; Muni, Rajeev H; McHardy, Paul

    2012-01-01

    The aims of this prospective observational study were to assess the incidence of intraconal spread during peribulbar (extraconal) anesthesia by real-time ultrasound imaging of the retro-orbital compartment and to determine whether a complete sensory and motor block (with akinesia) of the eye is directly related to the intraconal spread. Ultrasound imaging was performed in 100 patients who underwent a surgical procedure on the posterior segment of the eye. All patients received a peribulbar block using the inferolateral approach. Once the needle was in place, a linear ultrasound transducer was placed over the eyelid and the spread of local anesthetics was assessed during the injection (real time). Akinesia was assessed by a blinded observer 10 minutes after block placement. The incidence of intraconal spread and its correlation with a complete akinesia was measured. The overall block failure rate was 28% in terms of akinesia, and the rate of rescue blocks was 20%. Clear intraconal spread during injection of the local anesthetic mixture could be detected with ultrasound imaging in 61 of 100 patients. The positive predictive value for successful block when intraconal spread was detected was 98% (95% confidence interval, 91%-100%). The association between clear and no evidence of intraconal spread and effective block was statistically significant (χ test, P < 0.001). Ultrasound imaging provides information of local anesthetic spread within the retro-orbital space, which might assist in the prediction of block success.

  6. Historical Cavern Floor Rise for All SPR Sites

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

    Moriarty, Dylan Michael

    2016-09-01

    The Strategic Petroleum Reserve (SPR) contains the largest supply is the largest stockpile of government-owned emergency crude oil in the world. The oil is stored in multiple salt caverns spread over four sites in Louisiana and Texas. Cavern infrastructure near the bottom of the cavern can be damaged from vertical floor movement. This report presents a comprehensive history of floor movements in each cavern. Most of the cavern floor rise rates ranged from 0.5-3.5 ft/yr, however, there were several caverns with much higher rise rates. BH103, BM106, and BH105 had the three highest rise rates. Information from this report willmore » be used to better predict future vertical floor movements and optimally place cavern infrastructure. The reasons for floor rise are not entirely understood and should be investigated.« less

  7. Sonar surveys used in gas-storage cavern analysis

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

    Crossley, N.G.

    1998-05-04

    Natural-gas storage cavern internal configuration, inspection information, and cavern integrity data can be obtained during high-pressure operations with specialized gas-sonar survey logging techniques. TransGas Ltd., Regina, Sask., has successfully performed these operations on several of its deepest and highest pressurized caverns. The data can determine gas-in-place inventory and assess changes in spatial volumes. These changes can result from cavern creep, shrinkage, or closure or from various downhole abnormalities such as fluid infill or collapse of the sidewall or roof. The paper discusses conventional surveys with sonar, running surveys in pressurized caverns, accuracy of the sonar survey, initial development of Cavernmore » 5, a roof fall, Cavern 4 development, and a damaged string.« less

  8. Two- versus four-handed techniques for endonasal resection of orbital apex tumors.

    PubMed

    Craig, John R; Lee, John Y K; Petrov, Dmitriy; Mehta, Sonul; Palmer, James N; Adappa, Nithin D

    2015-01-01

    Open versus endonasal resection of orbital apex (OA) tumors is generally based on tumor size, location, and pathology. For endonasal resection, two- and four-handed techniques have been reported, but whether one technique is more optimal based on these tumor features has not been evaluated. To determine whether two- versus four-handed techniques result in better outcomes after endoscopic resection of OA tumors, and whether either technique is better suited for intra- versus extraconal location and for benign versus malignant pathology. A retrospective review of all expanded endonasal approaches for OA tumors was performed at a single institution from 2009 to 2013. A PubMed database search was also performed to review series published on endonasal OA tumor resection. Across all the cases reviewed, the following data were recorded: two- versus four-handed techniques, intra- versus extraconal tumor location, and benign versus malignant pathology. The relationship between these variables and resection extent was analyzed by the Fisher exact test. Postoperative visual status and complications were also reviewed. Ten cases from the institution and 94 cases from 17 publications were reviewed. Both two- and four-handed techniques were used to resect extra- and intraconal OA tumors, for both benign and malignant pathology. Four-handed techniques included a purely endonasal approach and a combined endonasal-orbital approach. On univariate analysis, the strongest predictor of complete resection was benign pathology (p = 0.005). No significant difference was found between the extent of resection and a two- versus a four-handed technique. Visual status was improved or unchanged in 94% of cases, and other complications were rare. Benign tumors that involve the medial extraconal and posterior inferomedial intraconal OA can be treated by either two- or four-handed endonasal techniques. Selecting two- versus four-handed techniques and endonasal versus endonasal-orbital four

  9. Crater Formation Above Salt Caverns: Piston vs Hour-glass

    NASA Astrophysics Data System (ADS)

    Berest, P.

    2016-12-01

    Conditions leading to crater formation above salt caverns are discussed. In most cases, at the end of leaching, the cavern roof had reached the top of the salt formation, allowing direct contact between brine and marl (or argillite) layers that compose the overburden of the salt formation. These layers are prone to weathering when in contact with saturated brine. Stoping takes place, and the cavern roof rises through the overburden. This process may be several years or dozens of years long. In Lorraine salt formations, stoping stops when the rising cavern top reaches a competent layer, the Beaumont Dolomite. Operators then lower cavern-brine pressure to trigger collapse. A rigid cylinder of rock (a "piston") drops into the cavern, and a crater whose initial edges are vertical is created. Cavern drop is more abrupt when the cavern top is filled partly with air. The contour of the piston is circular, as a circle is the shape such that the ratio between perimeter and area is minimal. In other cases, for instance in Kansas, the cavern rises until the uppermost keystone in the bedrock at shallow depth is breached, permitting loose materials to flow into the cavern through a relatively narrow hole at the bottom of the sink hole, as in an hour glass.

  10. The association of carotid cavernous fistula with Graves’ ophthalmopathy

    PubMed Central

    Celik, Ozlem; Buyuktas, Deram; Islak, Civan; Sarici, A Murat; Gundogdu, A Sadi

    2013-01-01

    Graves’ ophthalmopathy (GO) is one of the frequent manifestations of the disorder which is an inflammatory process due to fibroblast infiltration, fibroblast proliferation and accumulation of glycosaminoglycans. Eye irritation, dryness, excessive tearing, visual blurring, diplopia, pain, visual loss, retroorbital discomfort are the symptoms and they can mimic carotid cavernous fistulas. Carotid cavernous fistulas are abnormal communications between the carotid arterial system and the cavernous sinus. The clinical manifestations of GO can mimic the signs of carotid cavernous fistulas. Carotid cavernous fistulas should be considered in the differential diagnosis of the GO patients especially who are not responding to the standard treatment and when there is a unilateral or asymmetric eye involvement. Here we report the second case report with concurrent occurrence of GO and carotid cavernous fistula in the literature. PMID:23571267

  11. Computed tomographic diagnosis of unilateral cavernous sinus syndrome caused by a chondrosarcoma in a dog: a case report.

    PubMed

    Hernández-Guerra, Angel María; Del Mar López-Murcia, María; Planells, Alicia; Corpa, Juan Manuel; Liste, Fernando

    2007-07-01

    An eight-year old Rottweiler dog was presented with signs of enophthalmia, ptosis, anisocoria and mydriasis of the right eye, which showed visual disturbance, reduced or absent reflexes, and ophthalmoplegia. Consensual pupillary light reflex was also absent in the left eye. These neurological deficits were compatible with cavernous sinus syndrome. Computed tomography images of the cavernous sinus and the optical fissure revealed a mildly calcified mass arising from the right presphenoid bone extending further caudally into the orbital foramina. This extension of the mass affected the normal function of several cranial nerves. The dog was euthanased within one year of the initial presentation following development of forebrain signs. A chondrosarcoma was diagnosed histologically after necropsy.

  12. Brainstem Cavernous Angioma

    MedlinePlus

    ... echo” (as opposed to spin-echo or proton beam) imaging. Gradient-echo MRI is most efficient at ... radiosurgery for cavernous malformations: Kjellberg's experience with proton beam therapy in 98 cases at the Harvard Cyclotron. ...

  13. Cavernous sinus thrombosis caused by contralateral sphenoid sinusitis: a case report

    PubMed Central

    2013-01-01

    Objective To report a rare case of unilateral cavernous sinus thrombosis caused by contralateral sphenoid sinusitis. Case report A 33-year-old female visited our hospital for severe, right-sided, temporal headache, chemosis, periorbital edema, and proptosis. These signs were associated with congested erythematous nasal mucosa with purulent discharge from the right superior nasal meatus. Contrast enhanced CT showed dilated left superior ophthalmic vein, suggestive of thrombosis, contrast enhancement of the left cavernous sinuses, and dilation of cavernous sinus, indicating cavernous sinus inflammation. The right maxillary, ethmoid and sphenoid sinuses showed mucosal thickening and retention of purulent material. She was diagnosed with cavernous sinus thrombosis caused by contralateral sphenoid sinusitis. All clinical symptoms and signs improved after endoscopic sphenoidotomy and appropriate medical treatment. Conclusions Sphenoiditis can cause contralateral cavernous sinus thrombosis. Early surgical sphenoidotomy and aggressive medical treatment are the cornerstones of successful management of this life-threatening complication. PMID:23497466

  14. [Endovascular treatment of carotid-cavernous fistula type A with platinium coils].

    PubMed

    Culafić, Slobodan; Juszkat, Robert; Rusović, Sinisa; Stefanović, Dara; Minić, Ljubodrag; Spaić, Milan

    2008-12-01

    Carotid-cavernous fistulas are abnormal communications between carotid arteries or their branches and the cavernous system caused mostly by trauma. Posttraumatic fistulas represent 70% of all carotid-cavernous fistulas and they are mostly high-flow shunts (type A). This type gives characteristic eye symptoms. This paper presents a 44-year old male patient with carotid-cavernous fistula as a result of penetrating head injury. In clinical presentation the patient had exophthalmos, conjunctival chemosis and weakening of vision on the right eye, headache and diplopia. Digital subtracted angiography showed high-flow carotid-cavernous fistula, which was vascularised from the left carotid artery and from vertebrobasilar artery. Endovascular embolization with platinum coils was performed through the transarterial route (endoarterial approach). Check angiogram confirmed that the fistula was closed and that no new communications developed. Embolization of complex carotid-cavernous fistula type A was successfully performed with platinum coils by endovascular approach.

  15. Carotid-cavernous fistula after functional endoscopic sinus surgery.

    PubMed

    Karaman, Emin; Isildak, Huseyin; Haciyev, Yusuf; Kaytaz, Asim; Enver, Ozgun

    2009-03-01

    Carotid-cavernous fistulas (CCFs) are anomalous communications between the carotid arterial system and the venous cavernous sinus. They can arise because of spontaneous or trauma causes. Most caroticocavernous fistulas are of spontaneous origin and unknown etiology. Spontaneous CCF may also be associated with cavernous sinus pathology such as arteriosclerotic changes of the arterial wall, fibromuscular dysplasia, or Ehler-Danlos syndrome. Traumatic CCFs may occur after either blunt or penetrating head trauma. Their clinical presentation is related to their size and to the type of venous drainage, which can lead to a variety of symptoms, such as visual loss, proptosis, bruit, chemosis, cranial nerve impairment, intracranial hemorrhage (rare), and so on. Treatment by endovascular transarterial embolization with electrolytically detachable coils is a very effective method for CCF with good outcomes. Carotid-cavernous fistulas have been rarely reported after craniofacial surgery and are uncommon pathologies in otolaryngology practice. In this study, we report a 40-year-old woman with CCF secondary to blunt trauma of functional endoscopic sinus surgery.

  16. Threat of a sinkhole: A reevaluation of Cavern 4, Bayou Choctaw salt dome, Louisiana

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

    Neal, J.T.; Todd, J.L.; Linn, J.K.

    1993-09-01

    Cavern Lake at Bayou Choctaw salt dome resulted from the failure of Cavern 7 in 1954. Uncontrolled solutioning of this cavern through the thin caprock had set the stage for overburden to collapse into the cavern below. A similar situation developed with nearby Cavern 4, but with less dissolutioning of the caprock. Because pressure loss was already a problem and because another 800 ft diameter lake would have endangered surface operations, solutioning of Cavern 4 was stopped and the cavern abandoned in 1957 in order to protect the already-small site. In 1978 the Strategic Petroleum Reserve (SPR) acquired a numbermore » of caverns at Bayou Choctaw, including Cavern 4, and the possible repeat of the Cavern 7 failure and formation of another lake thus became an issue. The cavern dimensions were re-sonared in 1980 for comparison with 1963 and 1977 surveys. Annual surface leveling between 1982--1992 showed less subsidence occurring than the site average, and a cavern monitoring system, installed in 1984, has revealed no anomalous motion. Repeat sonar surveys in 1992 showed very little, if any, change occurred since 1980 although a small amount of uncertainty exists as a result of changing sonar techniques. We conclude that significant additional solutioning or erosion of the caprock has not occurred and that there is no increased threat to SPR operations.« less

  17. Systematic Evaluation of Salt Cavern Well Integrity

    NASA Astrophysics Data System (ADS)

    Roberts, B. L.; Lord, D. L.; Lord, A. S.; Bettin, G.; Sobolik, S. R.; Park, B. Y.

    2017-12-01

    The U.S. Strategic Petroleum Reserve (SPR) holds a reserve of crude oil ( 700 million barrels) to help ease any interruptions in oil import to the United States. The oil is stored in a set of 63 underground caverns distributed across four sites along the U.S. Gulf Coast. The caverns were solution mined into salt domes at each of the four sites. The plastic nature of the salt is beneficial for the storage of crude oil as it heals any fractures that may occur in the salt. The SPR is responsible for operating and maintaining the nearly 120 wells used to access the storage caverns over operational lifetimes spanning decades. Salt creep can induce deformation of the well casing which must be remediated to insure cavern and well integrity. This is particularly true at the interface between the plastic salt and the rigid caprock. The Department of Energy, the SPR Management and Operations contractor, and Sandia National Laboratories has developed a multidimensional well-grading system for the salt cavern access wells. This system is designed to assign numeric grades to each well indicating its risk of losing integrity and remediation priority. The system consists of several main components which themselves may consist of sub-components. The main components consider such things as salt cavern pressure history, results from geomechanical simulations modeling salt deformation, and measurements of well casing deformation due to salt creep. In addition, the geology of the salt domes and their overlying caprock is also included in the grading. These multiple factors are combined into summary values giving the monitoring and remediation priority for each well. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  18. 36 CFR 7.47 - Carlsbad Caverns National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Carlsbad Caverns National Park. 7.47 Section 7.47 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.47 Carlsbad Caverns National Park. (a...

  19. 36 CFR 7.47 - Carlsbad Caverns National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Carlsbad Caverns National Park. 7.47 Section 7.47 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.47 Carlsbad Caverns National Park. (a...

  20. 36 CFR 7.47 - Carlsbad Caverns National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Carlsbad Caverns National Park. 7.47 Section 7.47 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.47 Carlsbad Caverns National Park. (a...

  1. 36 CFR 7.47 - Carlsbad Caverns National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Carlsbad Caverns National Park. 7.47 Section 7.47 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.47 Carlsbad Caverns National Park. (a...

  2. 36 CFR 7.47 - Carlsbad Caverns National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Carlsbad Caverns National Park. 7.47 Section 7.47 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.47 Carlsbad Caverns National Park. (a...

  3. Surgical Outcomes of Cavernous Sinus Syndrome in Pituitary Adenomas.

    PubMed

    Fu, Weilun; Duan, Lian; Geng, Sumin

    2017-11-01

    The type of pituitary adenoma with a manifestation that includes cavernous sinus syndrome is rare. Based on the clinical data of 70 patients, this study investigated the pathogenesis, imaging characteristics, and prognostic factors of pituitary adenoma with cavernous sinus syndrome. We conducted a retrospective analysis of the characteristics of patients with pituitary adenoma with cavernous sinus syndrome who received surgical treatment. The patients were classified into different prognosis groups according to the time required for them to recover from the cavernous sinus syndrome. Univariate analyses were conducted for the correlations between the prognosis and factors. Of the 3598 cases of pituitary adenomas, 70 (1.95%) presented cavernous sinus syndrome. Of the patients, 55.7% recovered within 2 weeks of surgery, 24.3% recovered from 2 weeks to 1 year after surgery, and 20% had not returned to normal after more than 1 year after surgery. Univariate analyses showed that shorter disease duration (P < 0.001), lower Knosp grade (P = 0.045), a transsphenoidal approach (P < 0.001), and associated pituitary apoplexy (P = 0.012) were predictive factors of early postoperative recovery. The prognosis of cavernous sinus syndrome differs depending on the mechanism of the syndrome. There was no significant difference in the prognosis between patients with total pituitary adenoma resection and subtotal resection. Timely surgery within 100 days of symptom occurrence, Knosp grade 0-2, and associated pituitary apoplexy are predictive factors of good prognosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Extraosseous, epidural cavernous hemangioma with back pain.

    PubMed

    Ozkal, Birol; Yaldiz, Can; Yaman, Onur; Ozdemır, Nail; Dalbayrak, Sedat

    2015-01-01

    Cavernous malformations are characterized by enlarged vascular structures located in benign neural tissues within the cerebellum and spinal cord of the central nervous system. Cavernous hemangiomas (CHs) account for 5% to 12% of all spinal vascular malformations. We removed a hemorrhagic thoracic mass in a 40-year-old male patient who presented with progressive neurological deficits. We found it appropriate to present this case due to its rarity.

  5. Analysis of SPR salt cavern remedial leach program 2013.

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

    Weber, Paula D.; Gutierrez, Karen A.; Lord, David L.

    The storage caverns of the US Strategic Petroleum Reserve (SPR) exhibit creep behavior resulting in reduction of storage capacity over time. Maintenance of oil storage capacity requires periodic controlled leaching named remedial leach. The 30 MMB sale in summer 2011 provided space available to facilitate leaching operations. The objective of this report is to present the results and analyses of remedial leach activity at the SPR following the 2011 sale until mid-January 2013. This report focuses on caverns BH101, BH104, WH105 and WH106. Three of the four hanging strings were damaged resulting in deviations from normal leach patterns; however, themore » deviations did not affect the immediate geomechanical stability of the caverns. Significant leaching occurred in the toes of the caverns likely decreasing the number of available drawdowns until P/D ratio criteria are met. SANSMIC shows good agreement with sonar data and reasonably predicted the location and size of the enhanced leaching region resulting from string breakage.« less

  6. Novel Evidence-Based Classification of Cavernous Venous Occlusive Disease.

    PubMed

    Pathak, Ram A; Rawal, Bhupendra; Li, Zhuo; Broderick, Gregory A

    2016-10-01

    The primary aim of our study was to determine whether an evidence-based rationale could categorize cavernous venous occlusive disease into mild, moderate and severe erectile dysfunction. A total of 863 patients underwent color duplex Doppler ultrasound from January 2010 to June 2013 performed by a single urologist. We identified a cohort of 75 patients (8.7%) with a diagnosis of cavernous venous occlusive disease based on a unilateral resistive index less than 0.9, and right and left peak systolic velocity 35 cm per second or less after visual sexual stimulation. At a median followup of 13 months patients were evaluated for treatment efficacy. A total of 75 patients with a median age of 60 years (range 19 to 83) and a mean body mass index of 26.3 kg/m(2) (range 19.0 to 39.3) satisfied the criteria of cavernous venous occlusive disease. When substratified into tertiles, resistive index cutoffs were obtained, including mild cavernous venous occlusive disease-81.6 to 94.0, moderate disease-72.6 to 81.5 and severe disease-59.5 to 72.5. Using these 3 groups the phosphodiesterase type 5-inhibitor failure rate (p = 0.017) and SHIM (Sexual Health Inventory for Men) score categories (1 to 10 vs 11 to 20, p = 0.030) were statistically significantly different for mild, moderate and severe cavernous venous occlusive disease. Treatment satisfaction was also statistically significantly different. Penile prosthetic placement was a more common outcome among patients with erectile dysfunction and more severe cavernous venous occlusive disease. Our retrospective analysis supports a correlation between the phosphodiesterase type 5 inhibitor failure rate, SHIM score and the rate of surgical intervention using resistive index values. Our data further suggest that an evidence-based classification of cavernous venous occlusive disease by color Doppler ultrasound is possible and can triage patients to penile prosthetic placement. Copyright © 2016 American Urological Association

  7. Analogue of Caldera Dynamics: the Controlled Salt Cavern Collapse

    NASA Astrophysics Data System (ADS)

    Jousset, P. G.; Rohmer, J.

    2012-12-01

    Caldera collapse (or pit-crater) dynamics are inferred from geological observations and laboratory experiments. Here, we present an analogue of caldera collapse at field scale and possible analogy with large scale caldera dynamics. Through an original exploitation technique in sedimentary environment, a salt layer is emptied, leaving a brine-filled cavern, which eventually collapses after overburden falls into the cavern. Such a collapse was monitored in East France by many instruments (including GPS, extensometers, geophones, broadband seismological sensors, tiltmeter, gravity meter, … ), which allowed us to describe mechanisms of the collapse. Micro-seismicity is a good indicator of spatio-temporal evolution of physical properties of rocks prior to catastrophic events like volcanic eruptions or landslides and may be triggered by a number of causes including dynamic characteristics of processes in play or/and external forces. We show evidence of triggered micro-seismicity observed in the vicinity of this underground salt cavern prone to collapse by a remote M~7.2 earthquake, which occurred ~12000 kilometres away. High-dynamic broadband records reveal the strong time-correlation between a dramatic change in the rate of local high-frequency micro-seismicity and the passage of low-frequency seismic waves, including body, Love and Rayleigh surface waves. Pressure was lowered in the cavern by pumping operations of brine out of the cavern. We demonstrate the near critical state of the cavern before the collapse by means of 2D axisymmetric elastic finite-element simulations. Stress oscillations due to the seismic waves may have exceeded the strength required for the rupture of the complex media made of brine and rock triggering micro-earthquakes and leading to damage of the overburden and eventually collapse of the salt cavern. The increment of stress necessary for the failure of a Dolomite layer is of the same order or magnitude as the maximum dynamic stress magnitude

  8. [Surgical treatment of diffuse adult orbital lymphangioma: two case studies].

    PubMed

    Berthout, A; Jacomet, P V; Putterman, M; Galatoire, O; Morax, S

    2008-12-01

    Orbital lymphangioma is a rare vascular malformation; it is a benign but severe anomaly because of its infiltrative, diffuse, and hemorrhagic nature, and its high morbidity rate. Surgical resection is a real challenge on account of the intricate architecture of the lesion. The authors report their surgical experience concerning two cases of diffuse orbital lymphangioma whose diagnosis was established in adulthood and whose surgical treatment was successful. Two patients presented with adult orbital lymphangioma. Progression was slow during the first decade and then was quickly followed by complications: major exorbitism, compressive optic neuropathy, and corneal exposure. Neuroimaging showed a diffuse and cystic orbital malformation. Surgical resection was performed as completely as possible, in one case with a Krönlein orbitotomy and in the other case only via a conjunctive route. An aspirate drain was put in the orbit for 48 h so as to prevent dead spaces forming after resection, an essential risk factor of hemorrhagic or cystic recurrence. Systemic corticotherapy was administered for the 5 days following surgery. The resection was total in one case and subtotal in the other. The surgical follow-up was uneventful with an excellent aesthetic result and an improvement in visual acuity. After 12 months, no tumoral or hemorrhagic recurrence was noted. The surgical treatment of orbital lymphangiomas is challenging because of their infiltrative nature. In diffuse forms, a complete resection is rarely possible because of the risk of sacrificing visual function. In the two cases reported herein, the resection of the extraconal portion was complete, but the intraconal portion was completely removed only in one case. Using the aspirate drain, negative pressure was maintained in the orbital cavity, preventing the formation of chocolate cysts induced by surgery. Although the clinical result was very satisfying, long-term follow-up is necessary to evaluate recurrence

  9. Intra-cone plumbing system and eruptive dynamics of small-volume basaltic volcanoes: A case study in the Calatrava Volcanic Field

    NASA Astrophysics Data System (ADS)

    Carracedo-Sánchez, M.; Sarrionandia, F.; Ábalos, B.; Errandonea-Martin, J.; Gil Ibarguchi, J. I.

    2017-12-01

    The Manoteras volcano (Tortonian to Pleistocene, Calatrava Volcanic Field, Spain) is composed of a scoria and spatter cone surrounded by a field of pahoehoe lava. The volcanic cone is made essentially of vitreous lapilli-tuffs with intercalations of vitreous tuffs and spatter deposits, without any intercalations of lava flows. Erosion has uncovered an intra-cone plumbing system formed by coherent dykes and pyroclastic dykes (mixed-type dykes). This dyke swarm reflects processes of intrusion at the end of the eruption or even post-eruption. All the volcanic products are nephelinitic in composition. The main dyke is up to 3.4 m thick and has an exposed length of 1000 m. It is composed mostly of coherent nephelinite with some pyroclastic sections at its northern extremity. This dyke is regarded as a feeder dyke of the volcano, although the upper parts of the dike have been eroded, which prevents the observation of the characteristics and nature of the possible overlying vent(s). Mixed-type dykes could also have acted as small linear vents and indicate that the magma fragmentation level during final waning stages of the eruption was located inside the volcanic cone. The pyroclastic deposits that make up the volcanic cone at the current exposure level were probably developed during a major phase of violent Strombolian style that formed the scoria cone, followed by a Hawaiian phase that formed the summital intracrater spatter deposit. Three central-type vents have been identified: one at the highest point of the remnant volcanic cone (summital vent), from where the earlier explosive eruptions took place, and the other two at the fringe of the cone base, from where emissions were only effusive. The lava flows were emitted from these boccas through the scoria cone feeding the lava field. The results obtained, based on careful field observations, add substantial complexity to the proposed eruptive models for small-volume basaltic volcanoes as it appears evident that there

  10. Beta electron fluxes inside a magnetic plasma cavern: Calculation and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Stupitskii, E. L.; Smirnov, E. V.; Kulikova, N. A.

    2010-12-01

    We study the possibility of electrostatic blanking of beta electrons in the expanding spherical blob of a radioactive plasma in a rarefied ionosphere. From numerical studies on the dynamics of beta electrons departing a cavern, we obtain the form of a function that determines the portion of departing electrons and calculate the flux density of beta electrons inside the cavern in relation to the Starfish Prime nuclear blast. We show that the flux density of electrons in geomagnetic flux tubes and inside the cavern depend on a correct allowance for the quantity of beta electrons returning to the cavern. On the basis of a physical analysis, we determine the approximate criterion for the return of electrons from a geomagnetic flux tube to the cavern. We compare calculation results in terms of the flux density of beta electrons inside the cavern with the recently published experimental results from operation Starfish Prime.

  11. Thermo-mechanical modelling of salt caverns due to fluctuating loading conditions.

    NASA Astrophysics Data System (ADS)

    Böttcher, N.

    2015-12-01

    This work summarizes the development and application of a numerical model for the thermo-mechanical behaviour of salt caverns during cyclic gas storage. Artificial salt caverns are used for short term energy storage, such as power-to-gas or compressed air energy storage. Those applications are characterized by highly fluctuating operation pressures due to the unsteady power levels of power plants based on renewable energy. Compression and expansion of the storage gases during loading and unloading stages lead to rapidly changing temperatures in the host rock of the caverns. This affects the material behaviour of the host rock within a zone that extends several meters into the rock mass adjacent to the cavern wall, and induces thermo-mechanical stresses and alters the creep response.The proposed model features the thermodynamic behaviour of the storage medium, conductive heat transport in the host rock, as well as temperature dependent material properties of rock salt using different thermo-viscoplastic material models. The utilized constitutive models are well known and state-of-the-art in various salt mechanics applications. The model has been implemented into the open-source software platform OpenGeoSys. Thermal and mechanical processes are solved using a finite element approach, coupled via a staggered coupling scheme. The simulation results allow the conclusion, that the cavern convergence rate (and thus the efficiency of the cavern) is highly influenced by the loading cycle frequency and the resulting gas temperatures. The model therefore allows to analyse the influence of operation modes on the cavern host rock or on neighbouring facilities.

  12. Analysis of cavern and well stability at the West Hackberry SPR site using a full-dome model.

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

    Sobolik, Steven R.

    2015-08-01

    This report presents computational analyses that simulate the structural response of caverns at the Strategic Petroleum Reserve (SPR) West Hackberry site. The cavern field comprises 22 caverns. Five caverns (6, 7, 8, 9, 11) were acquired from industry and have unusual shapes and a history dating back to 1946. The other 17 caverns (101-117) were leached according to SPR standards in the mid-1980s and have tall cylindrical shapes. The history of the caverns and their shapes are simulated in a three-dimensional geomechanics model of the site that predicts deformations, strains, and stresses. Future leaching scenarios corresponding to oil drawdowns usingmore » fresh water are also simulated by increasing the volume of the caverns. Cavern pressures are varied in the model to capture operational practices in the field. The results of the finite element model are interpreted to provide information on the current and future status of subsidence, well integrity, and cavern stability. The most significant results in this report are relevant to Cavern 6. The cavern is shaped like a bowl with a large ceiling span and is in close proximity to Cavern 9. The analyses predict tensile stresses at the edge of the ceiling during repressurization of Cavern 6 following workover conditions. During a workover the cavern is at low pressure to service a well. The wellhead pressures are atmospheric. When the workover is complete, the cavern is repressurized. The resulting elastic stresses are sufficient to cause tension around the edge of the large ceiling span. With time, these stresses relax to a compressive state because of salt creep. However, the potential for salt fracture and propagation exists, particularly towards Cavern 9. With only 200 feet of salt between the caverns, the operational consequences must be examined if the two caverns become connected. A critical time may be during a workover of Cavern 9 in part because of the operational vulnerabilities, but also because

  13. Japan's exploration of vertical holes and subsurface caverns on the Moon and Mars

    NASA Astrophysics Data System (ADS)

    Haruyama, J.; Kawano, I.; Kubota, T.; Yoshida, K.; Kawakatsu, Y.; Kato, H.; Otsuki, M.; Watanabe, K.; Nishibori, T.; Yamamoto, Y.; Iwata, T.; Ishigami, G.; Yamada, T. T.

    2013-12-01

    Recently, gigantic vertical holes exceeding several tens of meters in diameter and depth were discovered on the Moon and Mars. Based on high-resolution image data, lunar holes and some Martian pits (called 'holes' hereafter) are probably skylights of subsurface caverns such as lava tubes or magma chambers. We are starting preparations for exploring the caverns through the vertical holes. The holes and subsurface caverns have high potential as resources for scientific studies. Various important geological and mineralogical processes could be uniquely and effectively observed inside these holes and subsurface caverns. The exposed fresh lava layers on the vertical walls of the lunar and Martian holes would provide information on volcanic eruption histories. The lava layers may also provide information on past magnetic fields of the celestial bodies. The regolith layers may be sandwiched between lava layers and may preserve volatile elements including solar wind protons that could be a clue to understanding past solar activities. Water molecules from solar winds or cometary/meteorite impacts may be stored inside the caverns because of mild temperatures there. The fresh lava materials forming the walls and floors of caverns might trap endogenic volatiles from magma eruptions that will be key materials for revealing the formation and early evolution of the Moon and Mars. Furthermore, the Martian subsurface caverns are highly expected to be life cradles where the temperatures are probably stable and that are free from ultra-violet and other cosmic rays that break chemical bonds, thus avoiding polymerization of molecules. Discovering extraterrestrial life and its varieties is one of our ultimate scientific purposes for exploring the lunar and Martian subsurface caverns. In addition to scientific interests, lunar and Martian subsurface caverns are excellent candidates for future lunar bases. We expect such caverns to have high potential due to stable temperatures; absence

  14. A NOVEL PROCESS TO USE SALT CAVERNS TO RECEIVE SHIP BORNE LNG

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

    Michael M. McCall; William M. Bishop; Marcus Krekel

    2005-05-31

    This cooperative research project validates use of man made salt caverns to receive and store the cargoes of LNG ships in lieu of large liquid LNG tanks. Salt caverns will not tolerate direct injection of LNG because it is a cryogenic liquid, too cold for contact with salt. This research confirmed the technical processes and the economic benefits of pressuring the LNG up to dense phase, warming it to salt compatible temperatures and then directly injecting the dense phase gas into salt caverns for storage. The use of salt caverns to store natural gas sourced from LNG imports, particularly whenmore » located offshore, provides a highly secure, large scale and lower cost import facility as an alternative to tank based LNG import terminals. This design can unload a ship in the same time as unloading at a tank based terminal. The Strategic Petroleum Reserve uses man made salt caverns to securely store large quantities of crude oil. Similarly, this project describes a novel application of salt cavern gas storage technologies used for the first time in conjunction with LNG receiving. The energy industry uses man made salt caverns to store an array of gases and liquids but has never used man made salt caverns directly in the importation of LNG. This project has adapted and expanded the field of salt cavern storage technology and combined it with novel equipment and processes to accommodate LNG importation. The salt cavern based LNG receiving terminal described in the project can be located onshore or offshore, but the focus of the design and cost estimates has been on an offshore location, away from congested channels and ports. The salt cavern based terminal can provide large volumes of gas storage, high deliverability from storage, and is simplified in operation compared to tank based LNG terminals. Phase I of this project included mathematical modeling that proved a salt cavern based receiving terminal could be built at lower capital cost, and would have

  15. Optical Coherence Tomography Angiography of Retinal Cavernous Hemangioma.

    PubMed

    Pierro, Luisa; Marchese, Alessandro; Gagliardi, Marco; Bandello, Francesco

    2017-08-01

    Retinal cavernous hemangioma is a rare, benign, retinal tumor characterized by angiomatous proliferation of vessels within the inner retina or the optic disc.1 Here we report a case of retinal cavernous hemangioma on the margin of the optic disc in the right eye of a 61-year-old asymptomatic female. The lesion was studied with multimodal imaging which included structural optical coherence tomography, fluorescein angiography, blue fundus auto-fluorescence, optical coherence tomography angiography (OCTA) (DRI OCT Triton; Topcon, Tokyo, Japan) and visual field examination. Blood circulation inside retinal cavernous hemangioma lesion is typically low-stagnant.2 However, OCTA demonstrated blood flow inside the lesion, illustrating its vascular circulation.3 Visual field was within the normal limits, except from a slight enlargement of the blind spot. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:684-685.]. Copyright 2017, SLACK Incorporated.

  16. Construction of the bridge in the cavern in the Vrata tunnel (Croatia)

    NASA Astrophysics Data System (ADS)

    Garasic, Mladen; Sasa Kovacevic, Meho; Juric-Kacunic, Danijela

    2010-05-01

    In the Dinaric karst system in Croatia some 11500 speleological objects have been explored so far, more than 1000 of which were discovered during construction works. Such speleological objects without natural entrance on the terrain surface (which are called "caverns") have been discovered on the construction sites of the highways. Over the past twenty years they have been systematically investigated and treated. A special kind of remediation was conducted in the cavern's large hall of the "Vrata" tunnel on the Zagreb - Rijeka highway. Due to size, shape, cavern's position and hydrogeological parameters (fissured and karstified aquifers) within the karst system it was necessary to design and construct a 58 m bridge over the cavern. In addition, the cavern's vault had to be reinforced and stabilized, as the overburden was very thin. The beam-and -stringer grid with special anchors was used. The cavern's rehabilitation in the "Vrata" tunnel was a unique undertaking, and the bridge (without piers) is the cavern's longest bridge in the world. A speleological object of large dimensions was discovered in the "Vrata"tunnel's right tube on the Rijeka-Zagreb highway. Speleological, geotechnical, engineering geological and hydrogeological investigation works were carried out for the purpose of preservation the speleological object (cavern). On the basis of classification results of rock masses and conducted numerical analyses the support system for the cavern's vault stabilization was selected. The support system's elements include the beam-and-stringer grid constructed on the terrain's surface above the cavern, tendons and geotechnical anchors. To ensure stability of the speleological object, and to conduct the backward numerical analyses the measurement of vertical deformations from the terrain's surface along the rock's mass by means of sliding micrometers was undertaken. Backward numerical analyses combined with geotechnical measurements enable safer and more rational

  17. Instability risk analysis and risk assessment system establishment of underground storage caverns in bedded salt rock

    NASA Astrophysics Data System (ADS)

    Jing, Wenjun; Zhao, Yan

    2018-02-01

    Stability is an important part of geotechnical engineering research. The operating experiences of underground storage caverns in salt rock all around the world show that the stability of the caverns is the key problem of safe operation. Currently, the combination of theoretical analysis and numerical simulation are the mainly adopts method of reserve stability analysis. This paper introduces the concept of risk into the stability analysis of underground geotechnical structure, and studies the instability of underground storage cavern in salt rock from the perspective of risk analysis. Firstly, the definition and classification of cavern instability risk is proposed, and the damage mechanism is analyzed from the mechanical angle. Then the main stability evaluating indicators of cavern instability risk are proposed, and an evaluation method of cavern instability risk is put forward. Finally, the established cavern instability risk assessment system is applied to the analysis and prediction of cavern instability risk after 30 years of operation in a proposed storage cavern group in the Huai’an salt mine. This research can provide a useful theoretical base for the safe operation and management of underground storage caverns in salt rock.

  18. A singular case of cavernous internal carotid artery aneurysm in patient with cavernous sinus syndrome and bacterial meningitis.

    PubMed

    Sacchetti, Federico; Stagni, Silvia; Spinardi, Luca; Raumer, Luigi; Dentale, Nicola; Cirillo, Luigi

    2016-09-01

    We report the uncommon case of an acute cavernous sinus syndrome in a patient who was consequently discovered to have both a cavernous internal carotid artery aneurysm and bacterial meningitis. Which came first, the chicken or the egg? Which of the two, the aneurysm or the meningitis, gave rise to the patient's symptoms? We briefly reviewed the literature of similar cases and tried to analyze the possible pathophysiological relationship between these findings. Moreover, this case highlights the importance of a multidisciplinary management of these patients to better decide between a medical and a surgical and/or endovascular treatment.

  19. Direct carotid cavernous fistula after submucous resection of the nasal septum.

    PubMed

    Bizri, A R; al-Ajam, M; Zaytoun, G; al-Kutoubi, A

    2000-01-01

    A carotid cavernous fistula (CCF) is an abnormal arteriovenous anastomosis between the carotid artery and the cavernous sinus. Etiologies of this condition reported in the literature so far include facial trauma, rupture of an intracavernous aneurysm of the carotid artery, Ehler-Danlos syndrome and fibromuscular dysplasia of the cerebral arteries. Such fistulae were reported as complications of rhinoplasty, transsphenoidal surgery, embolization of cavernous sinus meningioma, and rhinocerebral mucormycosis. CCF may also occur spontaneously in children or as a congenital malformation. However, to our knowledge, submucous resection of the nasal septum has not been reported before to cause direct carotid-cavernous fistula. CT and angiographic findings are presented and a review of the literature for reported causes of CCF is made as well as a brief discussion of the possible pathophysiology.

  20. Orbital cellulitis demands early recognition, urgent admission and aggressive management.

    PubMed Central

    Tole, D M; Anderton, L C; Hayward, J M

    1995-01-01

    Orbital cellulitis is an emergency. Confusion still exists between the diagnosis of this serious condition and that of preseptal cellulitis. Delay in treatment may cause blindness and progression to life-threatening sequelae such as brain abscess, meningitis or cavernous sinus thrombosis. We report a case in which, despite late referral, emergency surgical intervention was sight saving. Images Fig. 1 Fig. 2 PMID:7582417

  1. Brainstem cavernous malformations: anatomical, clinical, and surgical considerations.

    PubMed

    Giliberto, Giuliano; Lanzino, Desiree J; Diehn, Felix E; Factor, David; Flemming, Kelly D; Lanzino, Giuseppe

    2010-09-01

    Symptomatic brainstem cavernous malformations carry a high risk of permanent neurological deficit related to recurrent hemorrhage, which justifies aggressive management. Detailed knowledge of the microscopic and surface anatomy is important for understanding the clinical presentation, predicting possible surgical complications, and formulating an adequate surgical plan. In this article the authors review and illustrate the surgical and microscopic anatomy of the brainstem, provide anatomoclinical correlations, and illustrate a few clinical cases of cavernous malformations in the most common brainstem areas.

  2. Osteologic analysis of ethnic differences in supernumerary ethmoidal foramina: implications for endoscopic sinus and orbit surgery.

    PubMed

    Mueller, Sarina K; Bleier, Benjamin S

    2018-05-01

    Knowledge of the position of the ethmoidal arteries is critical to enable safe endoscopic sinus and orbital surgery. The presence of a third or "middle" ethmoid variant has recently become more relevant as endoscopic intraconal surgery continues to advance. The purpose of this study was to quantify the presence of supernumerary (ie, over 2) ethmoid foramina in different ethnicities and genders. Morphometric osteologic measurements were performed in 273 orbits. Prevalence of supernumerary ethmoid foramina and orbital length data were obtained from human skulls of Asian (n = 54), Caucasian (n = 70), African (n = 39), Hispanic (n = 49), and Middle Eastern (n = 61) derivation. Correlations between gender, ethnicity, symmetry, orbital floor, and lamina papyracea length were assessed by analysis of variance, paired t test, and χ 2 test. Supernumerary foramina were identified in 95 of 273 orbits (34.79%). A significantly higher prevalence was seen in Asian (42.59%), African (41.02%), and Hispanic (41.00%) skulls as compared with Caucasian (25.71%) and Middle Eastern (22.95%) skulls (p < 0.05 for all). The length of the orbital floor was significantly shorter in the Asian (3.35 ± 1.52 cm) specimens (p < 0.01). Asians were found to have the highest risk of ethmoid artery injury compared with the other ethnic groups (ratio of number of supernumerary foramina to orbital floor length = 0.72). Supernumerary ethmoidal foramina were common among all orbits studied. Orbits of Asian and African derivation had significantly greater numbers of ethmoidal foramina, both unilaterally and symmetrically and within a shorter orbital length, suggesting a greater proximity between the ethmoidal vessels. Surgeons should be alert to the possible presence of middle ethmoidal vessels during endoscopic sinus and orbital approaches. © 2017 ARS-AAOA, LLC.

  3. Sensitivity of storage field performance to geologic and cavern design parameters in salt domes.

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

    Ehgartner, Brian L.; Park, Byoung Yoon

    2009-03-01

    A sensitivity study was performed utilizing a three dimensional finite element model to assess allowable cavern field sizes for strategic petroleum reserve salt domes. A potential exists for tensile fracturing and dilatancy damage to salt that can compromise the integrity of a cavern field in situations where high extraction ratios exist. The effects of salt creep rate, depth of salt dome top, dome size, caprock thickness, elastic moduli of caprock and surrounding rock, lateral stress ratio of surrounding rock, cavern size, depth of cavern, and number of caverns are examined numerically. As a result, a correlation table between the parametersmore » and the impact on the performance of storage field was established. In general, slower salt creep rates, deeper depth of salt dome top, larger elastic moduli of caprock and surrounding rock, and a smaller radius of cavern are better for structural performance of the salt dome.« less

  4. Induced Seismicity Monitoring of an Underground Salt Cavern Prone to Collapse

    NASA Astrophysics Data System (ADS)

    Mercerat, E. D.; Driad-Lebeau, L.; Bernard, P.

    2010-02-01

    Within the framework of a large research project launched to assess the feasibility of microseismic monitoring of growing underground caverns, this specific work focuses on the analysis of the induced seismicity recorded in a salt mine environment. A local seismic network has been installed over an underground salt cavern located in the Lorraine basin (Northeast of France). The microseismic network includes four 3-components and three single component geophones deployed at depths between 30 and 125 m in cemented boreholes drilled in the vicinity of the study area. The underground cavern under monitoring is located within a salt layer at 180 m depth and it presents a rather irregular shape that can be approximated by a cylindrical volume of 50 m height and 180 m diameter. Presently, the cavern is full of saturated brine inducing a significant pressure on its walls (~2.0 MPa) to keep the overburden mechanically stable. Nevertheless some small microseismic events were recorded by the network and analyzed (approximately 2,000 events in 2 years of recording). In October 2005 and April 2007, two controlled pressure transient experiments were carried out in the cavern, in order to analyze the mechanical response of the overburden by tracking the induced microseismicity. The recorded events were mainly grouped in clusters of 3-30 s of signal duration with emergent first arrivals and rather low frequency content (between 20 and 120 Hz). Some of these events have been spatially located by travel-time picking close to the actual cavern and its immediate roof. Preliminary spectral analysis of isolated microearthquakes suggests sources with non-negligible tensile components possibly related to fluid-filled cracks. Rock-debris falling into the cavern from delamination of clay marls in the immediate roof is probably another source of seismic excitation. This was later confirmed when the most important seismic swarms occurred at the site during May 2007, accompanied by the

  5. Simultaneous and sequential hemorrhage of multiple cerebral cavernous malformations: a case report.

    PubMed

    Louis, Nundia; Marsh, Robert

    2016-02-09

    The etiology of cerebral cavernous malformation hemorrhage is not well understood. Causative physiologic parameters preceding hemorrhagic cavernous malformation events are often not reported. We present a case of an individual with sequential simultaneous hemorrhages in multiple cerebral cavernous malformations with a new onset diagnosis of hypertension. A 42-year-old white man was admitted to our facility with worsening headache, left facial and tongue numbness, dizziness, diplopia, and elevated blood pressure. His past medical history was significant for new onset diagnosis of hypertension and chronic seasonal allergies. Serial imaging over the ensuing 8 days revealed sequential hemorrhagic lesions. He underwent suboccipital craniotomy for resection of the lesions located in the fourth ventricle and right cerebellum. One month after surgery, he had near complete resolution of his symptoms with mild residual vertigo but symptomatic chronic hypertension. Many studies have focused on genetic and inflammatory mechanisms contributing to cerebral cavernous malformation rupture, but few have reported on the potential of hemodynamic changes contributing to cerebral cavernous malformation rupture. Systemic blood pressure changes clearly have an effect on angioma pressures. When considering the histopathological features of cerebral cavernous malformation architecture, changes in arterial pressure could cause meaningful alterations in hemorrhage propensity and patterns.

  6. A cavernous sinus lesion clinically responsive to steroids.

    PubMed

    Ruff, M W; Carabenciov, I D; Johnson, D R; Pollock, B E; Parisi, J E; Klaas, J P

    2018-04-20

    Tolosa Hunt syndrome (THS) is characterized by painful ophthalmoplegia secondary to idiopathic granulomatous inflammation of the cavernous sinus. The characteristic finding on MRI is an enhancing T1 isointense and T2 hypo- or hyperintense cavernous sinus mass lesion, which may result in focal narrowing of the ipsilateral internal carotid artery. Although the incidence is quite rare, it is a common diagnostic consideration in cases that present with multiple cranial neuropathies. However, the differential diagnosis for a unilateral cavernous sinus lesion in adults is broad and includes neoplastic, inflammatory (such as sarcoidosis and immunoglobulin G4-related disease [IgG4-RD]), infectious etiologies (such as syphilis and leprosy), as well as vascular lesions. We describe a patient presenting with neurologic symptoms referable to a persistent unilateral cavernous sinus MRI abnormality, initially thought to be consistent with Tolosa-Hunt syndrome, that was clinically but not radiographically responsive to steroids. Following reevaluation due to the presence of new symptoms, pathology revealed that the abnormality was most consistent with chordoma, a rare skull based tumor. In patients with a presumed diagnosis of Tolosa-Hunt syndrome, close clinical and radiographic follow-up is imperative, with early consideration for biopsy in patients that fail to respond to treatment both clinically and radiographically. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Brainstem cavernous malformations: Natural history versus surgical management.

    PubMed

    Walcott, Brian P; Choudhri, Omar; Lawton, Michael T

    2016-10-01

    While brainstem cavernous malformations were once considered inoperable, improvements in patient selection, surgical exposures, intraoperative MRI-guidance, MR tractography, and neurophysiologic monitoring have resulted in good outcomes in the majority of operated patients. In a consecutive series of 104 patients with brainstem cavernous malformations, only 14% of patients experienced cranial nerve or motor dysfunction that was worse at late follow-up, relative to their preoperative condition. Outcomes were predicted by several factors, including larger lesion size, lesions that crossed the midline, the presence of a developmental venous anomaly, older age, and greater time interval from lesion hemorrhage to surgery. The 14% of patients who experienced a persistent neurological deficit as a result of surgery, while substantial from any perspective, compares favorably with the risks of observation based on a recent meta-analysis. Curative resection is a safe and effective treatment for brainstem cavernous malformations that will prevent re-hemorrhage in symptomatic patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Hypophysopexy technique for radiosurgical treatment of cavernous sinus pituitary adenoma.

    PubMed

    Couldwell, William T; Rosenow, Joshua M; Rovit, Richard L; Benzil, Deborah L

    2002-01-01

    Stereotactic radiosurgery is being used with increased frequency in the treatment of residual or recurrent pituitary adenomas. The major risk associated with radiosurgical treatment of residual or recurrent pituitary tumor adjacent to normal functional pituitary gland is radiation of the pituitary, which frequently leads to the development of hypopituitarism. The authors describe a technique of pituitary transposition to reduce the radiation dose to the normal pituitary gland in cases of planned radiosurgical treatment of residual pituitary adenoma within the cavernous sinus. A sellar exploration for tumor resection is performed, the pituitary gland is transposed from the region of the cavernous sinus, and a fat and fascia graft is interposed between the normal pituitary gland and the residual tumor in the cavernous sinus. The residual tumor may then be treated with stereotactic radiosurgery. The increased distance between the normal pituitary gland and the residual tumor facilitates treatment of the tumor with radiosurgery and reduces the radiation to the normal pituitary gland. An illustrative case of a young female with recurrent acromegaly and a pituitary adenoma invading the cavernous sinus is described.

  9. Cranio-orbital primary intraosseous haemangioma.

    PubMed

    Gupta, T; Rose, G E; Manisali, M; Minhas, P; Uddin, J M; Verity, D H

    2013-11-01

    Primary intraosseous haemangioma (IOH) is a rare benign neoplasm presenting in the fourth and fifth decades of life. The spine and skull are the most commonly involved, orbital involvement is extremely rare. We describe six patients with cranio-orbital IOH, the largest case series to date. Retrospective review of six patients with histologically confirmed primary IOH involving the orbit. Clinical characteristics, imaging features, approach to management, and histopathological findings are described. Five patients were male with a median age of 56. Pain and diplopia were the most common presenting features. A characteristic 'honeycomb' pattern on CT imaging was demonstrated in three of the cases. Complete surgical excision was performed in all cases with presurgical embolisation carried out in one case. In all the cases, histological studies identified cavernous vascular spaces within the bony tissue. These channels were lined by single layer of cytologically normal endothelial cells. IOCH of the cranio-orbital region is rare; in the absence of typical imaging features, the differential diagnosis includes chondroma, chondrosarcoma, bony metastasis, and lymphoma. Surgical excision may be necessary to exclude more sinister pathology. Intraoperative haemorrhage can be severe and may be reduced by preoperative embolisation.

  10. [Pericardial Cavernous Hemangioma;Report of a Case].

    PubMed

    Marui, Tsutomu; Azuma, Kenichirou; Arakawa, Yuki; Murakami, Eiji; Murakawa, Shinji

    2016-03-01

    A case of pericardial cavernous hemangioma is presented. A 62-year-old man had a chest pain and was referred to our hospital because of an abnormal shadow in the mediastinum. Chest computed tomography showed a hypervascular tumor of 2.0 cm in size at the left side of pulmonary artery. Magnetic resonance imaging findings suggested the mucinous part of the tumor, suggesting liposarcoma, thymoma, and neurinoma etc. At surgery, the tumor was found to be in the pericardial cavity. After pericardotomy, the tumor was resected. The diagnosis of the tumor was cavernous hemangioma. There was no evidence of recurrence 2 years after the operation.

  11. Frontal Lobe Cavernous Malformations in Pediatric Patients: Clinical Features and Surgical Outcomes.

    PubMed

    Wang, Chengjun; Zhao, Meng; Wang, Jia; Wang, Shuo; Jiang, Zhongli; Zhao, Jizong

    2018-01-01

    The purpose of this study is to investigate the clinical manifestations, surgical treatment, and neurologic outcomes of frontal lobe cavernous malformations in children. A retrospective analysis of 23 pediatric frontal lobe cavernous malformation patients who underwent surgical treatment in Beijing Tiantan Hospital was performed. The case series included 16 boys and 7 girls. Gross total removal without surgical mortality was achieved in all patients. The mean follow-up period after surgery was 33.1 months. Two patients who left hospital with motor deficits gradually recovered after rehabilitative treatment, and other patients were considered to be in excellent clinical condition. For symptomatic frontal lobe cavernous malformations, neurosurgical management should be the treatment of choice. Conservative treatment may be warranted in asymptomatic frontal lobe cavernous malformations, especially the deep-seated or eloquently located cases.

  12. Mathematical model of salt cavern leaching for gas storage in high-insoluble salt formations.

    PubMed

    Li, Jinlong; Shi, Xilin; Yang, Chunhe; Li, Yinping; Wang, Tongtao; Ma, Hongling

    2018-01-10

    A mathematical model is established to predict the salt cavern development during leaching in high-insoluble salt formations. The salt-brine mass transfer rate is introduced, and the effects of the insoluble sediments on the development of the cavern are included. Considering the salt mass conservation in the cavern, the couple equations of the cavern shape, brine concentration and brine velocity are derived. According to the falling and accumulating rules of the insoluble particles, the governing equations of the insoluble sediments are deduced. A computer program using VC++ language is developed to obtain the numerical solution of these equations. To verify the proposed model, the leaching processes of two salt caverns of Jintan underground gas storage are simulated by the program, using the actual geological and technological parameters. The same simulation is performed by the current mainstream leaching software in China. The simulation results of the two programs are compared with the available field data. It shows that the proposed software is more accurate on the shape prediction of the cavern bottom and roof, which demonstrates the reliability and applicability of the model.

  13. Cerebral Cavernous Malformation and Hemorrhage

    MedlinePlus

    ... of the bleeding can be divided into three groups: “Slow ooze”: blood slowly seeps through the cavern “walls” inside the ... after a bleed. This allows time for excess blood absorption, unmasking the ... were recorded in the group over this period. A 2015 Mayo study determined ...

  14. Hazard assessment of the stability of a cavern roof along the coastline

    NASA Astrophysics Data System (ADS)

    Reina, A.; Lollino, P.

    2009-04-01

    This work concerns the hazard assessment about the stability of a large shallow depth cavern, located along the coastline rocky sector of Polignano town (Apulia, Southern Italy) under an intensely urbanised area. This cavern, which lies at the sea level, has been created by a prolonged process of sea erosion within a rock mass formed of a lower stratified limestone mass and an upper Gravina Calcarenite mass. The thickness of the cavern roof, which has a dome shape, is less than 10 metres in the centre. Important buildings, as hotels and private houses, are located just above the top of the roof. Erosion processes have been observed to be still active along the whole cavern due to climate factors and, in particular, to sea salt weathering and sea spray effects. In 2007 a large calcarenite block, 3 m large, fell down from the cavern roof and consequently a field investigation campaign was carried out for a rational stabilization plan in order to understand the current stability conditions of the roof and the potential failure mechanism. Therefore, a thorough geo-structural survey has firstly been carried out, together with laboratory and in-situ testing for measuring the physical and mechanical properties of the calcarenite rock and of the corresponding joints. A monitoring system has also been planned and installed in order to measure the erosional rate and the block displacements in the cavern.

  15. Tolerance of cranial nerves of the cavernous sinus to radiosurgery

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

    Tishler, R.B.; Loeffler, J.S.; Alexander, E. III

    1993-09-20

    Stereotactic radiosurgery is becoming a more accepted treatment option for benign, deep seated intracranial lesions. However, little is known about the effects of large single fractions of radiation on cranial nerves. This study was undertaken to assess the effect of radiosurgery on the cranial nerves of the cavernous sinus. The authors examined the tolerance of cranial nerves (II-VI) following radiosurgery for 62 patients (42/62 with meningiomas) treated for lesions within or near the cavernous sinus. Twenty-nine patients were treated with a modified 6 MV linear accelerator (Joint Center for Radiation Therapy) and 33 were treated with the Gamma Knife (Universitymore » of Pittsburgh). Three-dimensional treatment plans were retrospectively reviewed and maximum doses were calculated for the cavernous sinus and the optic nerve and chiasm. Median follow-up was 19 months (range 3-49). New cranial neuropathies developed in 12 patients from 3-41 months following radiosurgery. Four of these complications involved injury to the optic system and 8 (3/8 transient) were the result of injury to the sensory or motor nerves of the cavernous sinus. There was no clear relationship between the maximum dose to the cavernous sinus and the development of complications for cranial nerves III-VI over the dose range used (1000-4000 cGy). For the optic apparatus, there was a significantly increased incidence of complications with dose. Four of 17 patients (24%) receiving greater than 800 cGy to any part of the optic apparatus developed visual complications compared with 0/35 who received less than 800 cGy (p = 0.009). Radiosurgery using tumor-controlling doses of up to 4000 cGy appears to be a relatively safe technique in treating lesions within or near the sensory and motor nerves (III-VI) of the cavernous sinus. The dose to the optic apparatus should be limited to under 800 cGy. 21 refs., 4 tabs.« less

  16. Visualization of hydraulic connections using Borehole Array around LPG Underground Storage Cavern

    NASA Astrophysics Data System (ADS)

    Shimo, M.; Mashimo, H.; Maejima, T.; Aoki, K.

    2006-12-01

    This paper presents a systematic approach to visualize the hydraulic connections within the fractured rock mass around the underground LPG storage caverns using array of water injection boreholes. By taking advantage that water injection boreholes are located so as to cover the storage caverns, a complete sketch of hydraulic conditions around the caverns, such as locations of water conducting fractures, hydraulic conductivity and groundwater pressure can be obtained. Applicability of the proposed techniques have been tested in an on-going construction project operated by JOGMEC, Japan Oil, Gas and Metals National Corporation, at Namikata, Western part of Japan. Three 26m x 30m x 485m caverns, located at 150 - 200 m below the ground surface in a granitic rock, are under construction. By systematically monitoring the pressure responses between the neighboring boreholes during drilling of total 387 boreholes around the two propane caverns, a spatial profile of the hydraulic connections and hydraulic conductivity around the caverns has been successfully obtained. Locations of localized depressurized zones created during an arch excavation have been detected by monitoring pressure in each borehole after stopping water supply to that borehole temporarily. Measurement has been conducted using each one of the 302 boreholes, one at a time. Observation shows that there is a clear correlation between total pressure drop and pressure gradient versus time curve on semi-logarithmic plot, dH/log10t, as expected by the numerical prediction. Regions where dH/log10t is larger than a certain criteria, determined by a numerical simulation for flow around a cavern in a rock with uniform hydraulic conductivity, have been evaluated as a depressurized zone caused by insufficient water supply, possibly due to existence of the high permeable zones. Separate pore pressure measurement around the caverns also supports this interpretation that a low pressure is prevailing near the borehole

  17. Cavernous antioxidant effect of green tea, epigallocatechin-3-gallate with/without sildenafil citrate intake in aged diabetic rats.

    PubMed

    Mostafa, T; Sabry, D; Abdelaal, A M; Mostafa, I; Taymour, M

    2013-08-01

    This study aimed to assess the cavernous antioxidant effect of green tea (GT), epigallocatechin-3-gallate (EGCG) with/without sildenafil citrate intake in aged diabetic rats. One hundred and four aged male white albino rat were divided into controls that received ordinary chow, streptozotocin (STZ)-induced aged diabetic rats, STZ-induced diabetic rats on infused green tea, induced diabetic rats on epigallocatechin-3-gallate and STZ-induced diabetic rats on sildenafil citrate added to EGCG. After 8 weeks, dissected cavernous tissues were assessed for gene expression of eNOS, cavernous malondialdehyde (MDA), glutathione peroxidase (GPx), cyclic guanosine monophosphate (cGMP), and serum testosterone (T). STZ-induced diabetic rats on GT demonstrated significant increase in cavernous eNOS, cGMP, GPx and significant decrease in cavernous MDA compared with diabetic rats. Diabetic rats on EGCG demonstrated significant increase in cavernous eNOS, cGMP, GPx and significant decrease in cavernous MDA compared with diabetic rats or diabetic rats on GT. Diabetic rats on EGCG added to sildenafil showed significant increase in cavernous eNOS, cGMP and significant decrease in cavernous MDA compared with other groups. Serum T demonstrated nonsignificant difference between the investigated groups. It is concluded that GT and EGCG have significant cavernous antioxidant effects that are increased if sildenafil is added. © 2012 Blackwell Verlag GmbH.

  18. Nasopharyngeal carcinoma presented as cavernous sinus tumour.

    PubMed

    Moona, Mohammad Shafi; Mehdi, Itrat

    2011-12-01

    A 32 year Libyan male presented with the complaints of headache and diplopia. He was diagnosed with a cavernous sinus meningioma on the basis of MRI findings but no initial biopsy was taken. Depending on the radiologic diagnosis the patient was treated with gamma knife surgery twice, abroad. During follow up he developed left ear deafness and left cervical lymph adenopathy. An ENT evaluation with biopsy from the nasopharynx and cervical lymph node was taken. The histopathologic diagnosis of the resected tumour showed a nasopharyngeal carcinoma with cervical lymph node metastasis (poorly differentiated lympho-epithelial carcinoma). The cavernous sinus tumour which was initially treated as a meningioma was in fact metastasis from the nasopharyngeal carcinoma, making this an interesting and rare occurrence.

  19. Horizontal natural gas storage caverns and methods for producing same

    DOEpatents

    Russo, Anthony

    1995-01-01

    The invention provides caverns and methods for producing caverns in bedded salt deposits for the storage of materials that are not solvents for salt. The contemplated salt deposits are of the bedded, non-domed variety, more particularly salt found in layered formations that are sufficiently thick to enable the production of commercially usefully sized caverns completely encompassed by walls of salt of the formation. In a preferred method, a first bore hole is drilled into the salt formation and a cavity for receiving insolubles is leached from the salt formation. Thereafter, at a predetermined distance away from the first bore hole, a second bore hole is drilled towards the salt formation. As this drill approaches the salt, the drill assumes a slant approach and enters the salt and drills through it in a horizontal direction until it intersects the cavity for receiving insolubles. This produces a substantially horizontal conduit from which solvent is controlledly supplied to the surrounding salt formation, leaching the salt and producing a concentrated brine which is removed through the first bore hole. Insolubles are collected in the cavity for receiving insolubles. By controlledly supplying solvent, a horizontal cavern is produced with two bore holes extending therefrom.

  20. Surgical cannulation of the superior ophthalmic vein for the treatment of previously embolized cavernous sinus dural arteriovenous fistulas: serial studies and angiographic follow-up.

    PubMed

    Luo, Bin; Zhang, Xin; Duan, Chuan-Zhi; He, Xu-Ying; Li, Xi-Feng; Karuna, Tamrakar; Gu, Da-Qun; Long, Xiao-Ao; Li, Tie-Lin; Zhang, Shi-Zhong; Ke, Yi-Quan; Jiang, Xiao-Dan

    2013-04-01

    The purpose of this study was to evaluate the safety and efficacy of transorbital puncture for the retreatment of previously embolized cavernous sinus dural arteriovenous fistulas (DAVFs) via a superior ophthalmic vein (SOV) approach. During a 12-year period, 9 consecutive patients with previously embolized cavernous sinus DAVFs underwent retreatment via the transorbital SOV approach. All of the nine cases of previously embolized cavernous sinus DAVFs were successfully embolized. Clinical follow-ups were conducted in all nine cases at the duration of 17-141 months (61.22 ± 39.13 months). No recanalization occurred during the follow-up period. A subtle ptosis appeared in two patients and disappeared in one of the two cases after a 4-year follow-up. One patient suffered from paroxysmal positional vertigo and bruit for nearly 2 years after the treatment, but the follow-up angiography demonstrated no recurrence. One patient had persistent visual impairment caused by the initial venous stasis retinopathy. One patient with a history of a procedure-related transient decrease in visual acuity had it return to the normal level. The remaining four cases had clear improvement in the ocular symptoms and became completely asymptomatic during the follow-up period. No patient worsened or developed new symptoms. The approach of surgical cannulation of the SOV for the retreatment of previously embolized cavernous sinus DAVFs was proved feasible and efficient, especially when the transarterial and transfemoral venous approaches were inaccessible. However, if the SOV is not dilated enough or is located deeply in the orbit, transorbital venous puncture access may not be possible.

  1. EVOKED CAVERNOUS ACTIVITY: NEUROANATOMIC IMPLICATIONS

    PubMed Central

    Yilmaz, Ugur; Vicars, Brenda; Yang, Claire C.

    2013-01-01

    We investigated the autonomic innervation of the penis by using evoked cavernous activity (ECA). We recruited 7 males with thoracic spinal cord injury (SCI) and sexual dysfunction and 6 males who were scheduled to have pelvic surgery (PS), specifically non-nerve-sparing radical cystoprostatectomy. In the PS subjects, ECA was performed both pre- and postoperatively. The left median nerve was electrically stimulated and ECA was recorded with two concentric electromyography needles placed into the right and left cavernous bodies. We simultaneously recorded hand and foot sympathetic skin responses (SSRs) as controls. In the SCI group, all but one subject had reproducible hand SSRs. None of these subjects had ECA or foot SSRs. All the PS subjects had reproducible ECA and SSRs, both preoperatively and postoperatively. There was no difference in the latency and amplitude measurements of ECA and SSRs in the postoperative compared to the preoperative period (p>0.05). In conclusion, ECA is absent in men with SCI above the sympathetic outflow to the genitalia. In men following radical pelvic surgery, ECA is preserved, indicating the preservation of sympathetic fibers. PMID:19609298

  2. Cranio-orbital primary intraosseous haemangioma

    PubMed Central

    Gupta, T; Rose, G E; Manisali, M; Minhas, P; Uddin, J M; Verity, D H

    2013-01-01

    Purpose Primary intraosseous haemangioma (IOH) is a rare benign neoplasm presenting in the fourth and fifth decades of life. The spine and skull are the most commonly involved, orbital involvement is extremely rare. We describe six patients with cranio-orbital IOH, the largest case series to date. Patients and methods Retrospective review of six patients with histologically confirmed primary IOH involving the orbit. Clinical characteristics, imaging features, approach to management, and histopathological findings are described. Results Five patients were male with a median age of 56. Pain and diplopia were the most common presenting features. A characteristic ‘honeycomb' pattern on CT imaging was demonstrated in three of the cases. Complete surgical excision was performed in all cases with presurgical embolisation carried out in one case. In all the cases, histological studies identified cavernous vascular spaces within the bony tissue. These channels were lined by single layer of cytologically normal endothelial cells. Discussion IOCH of the cranio-orbital region is rare; in the absence of typical imaging features, the differential diagnosis includes chondroma, chondrosarcoma, bony metastasis, and lymphoma. Surgical excision may be necessary to exclude more sinister pathology. Intraoperative haemorrhage can be severe and may be reduced by preoperative embolisation. PMID:23989119

  3. Evidence for remotely triggered micro-earthquakes during salt cavern collapse

    NASA Astrophysics Data System (ADS)

    Jousset, P.; Rohmer, J.

    2012-04-01

    Micro-seismicity is a good indicator of spatio-temporal evolution of physical properties of rocks prior to catastrophic events like volcanic eruptions or landslides and may be triggered by a number of causes including dynamic characteristics of processes in play or/and external forces. Micro-earthquake triggering has been in the recent years the subject of intense research and our work contribute to showing further evidence of possible triggering of micro-earthquakes by remote large earthquakes. We show evidence of triggered micro-seismicity in the vicinity of an underground salt cavern prone to collapse by a remote M~7.2 earthquake, which occurred ~12000 kilometres away. We demonstrate the near critical state of the cavern before the collapse by means of 2D axisymmetric elastic finite-element simulations. Pressure was lowered in the cavern by pumping operations of brine out of the cavern. We demonstrate that a very small stress increase would be sufficient to break the overburden. High-dynamic broadband records reveal a remarkable time-correlation between a dramatic increase of the local high-frequency micro-seismicity rate associated with the break of the stiffest layer stabilizing the overburden and the passage of low-frequency remote seismic waves, including body, Love and Rayleigh surface waves. Stress oscillations due to the seismic waves exceeded the strength required for the rupture of the complex media made of brine and rock triggering micro-earthquakes and leading to damage of the overburden and eventually collapse of the salt cavern. The increment of stress necessary for the failure of a Dolomite layer is of the same order or magnitude as the maximum dynamic stress magnitude observed during the passage of the earthquakes waves. On this basis, we discuss the possible contribution of the Love and Rayleigh low-frequency surfaces waves.

  4. Simulation of Mechanical Processes in Gas Storage Caverns for Short-Term Energy Storage

    NASA Astrophysics Data System (ADS)

    Böttcher, Norbert; Nagel, Thomas; Kolditz, Olaf

    2015-04-01

    In recent years, Germany's energy management has started to be transferred from fossil fuels to renewable and sustainable energy carriers. Renewable energy sources such as solar and wind power are subjected by fluctuations, thus the development and extension of energy storage capacities is a priority in German R&D programs. This work is a part of the ANGUS+ Project, funded by the federal ministry of education and research, which investigates the influence of subsurface energy storage on the underground. The utilization of subsurface salt caverns as a long-term storage reservoir for fossil fuels is a common method, since the construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to solution mining. Another advantage of evaporate as host material is the self-healing behaviour of salt rock, thus the cavity can be assumed to be impermeable. In the framework of short-term energy storage (hours to days), caverns can be used as gas storage reservoirs for natural or artificial fuel gases, such as hydrogen, methane, or compressed air, where the operation pressures inside the caverns will fluctuate more frequently. This work investigates the influence of changing operation pressures at high frequencies on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. The salt behaviour is described by well-known constitutive material models which are capable of predicting creep, self-healing, and dilatancy processes. Our simulations include the thermodynamic behaviour of gas storage process, temperature development and distribution on the cavern boundary, the deformation of the cavern geometry, and the prediction of the dilatancy zone. Based on the numerical results, optimal operation modes can be found for individual caverns, so the risk of host rock damage

  5. Salinization of groundwater around underground LPG storage caverns, Korea : statistical interpretation

    NASA Astrophysics Data System (ADS)

    Lee, J.; Chang, H.

    2001-12-01

    In this research, we investigate the reciprocal influence between groundwater flow and its salinization occurred in two underground cavern sites, using major ion chemistry, PCA for chemical analysis data, and cross-correlation for various hydraulic data. The study areas are two underground LPG storage facilities constructed in South Sea coast, Yosu, and West Sea coastal regions, Pyeongtaek, Korea. Considerably high concentration of major cations and anions of groundwaters at both sites showed brackish or saline water types. In Yosu site, some great chemical difference of groundwater samples between rainy and dry season was caused by temporal intrusion of high-saline water into propane and butane cavern zone, but not in Pyeongtaek site. Cl/Br ratios and δ 18O- δ D distribution for tracing of salinization source water in both sites revealed that two kind of saline water (seawater and halite-dissolved solution) could influence the groundwater salinization in Yosu site, whereas only seawater intrusion could affect the groundwater chemistry of the observation wells in Pyeongtaek site. PCA performed by 8 and 10 chemical ions as statistical variables in both sites showed that intensive intrusion of seawater through butane cavern was occurred at Yosu site while seawater-groundwater mixing was observed at some observation wells located in the marginal part of Pyeongtaek site. Cross-correlation results revealed that the positive relationship between hydraulic head and cavern operating pressure was far more conspicuous at propane cavern zone in both sites (65 ~90% of correlation coefficients). According to the cross-correlation results of Yosu site, small change of head could provoke massive influx of halite-dissolved solution from surface through vertically developed fracture networks. However in Pyeongtaek site, the pressure-sensitive observation wells are not completely consistent with seawater-mixed wells, and the hydraulic change of heads at these wells related to the

  6. Assessment of the Available Drawdowns for Oil Storage Caverns at the West Hackberry SPR Site

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

    Sobolik, Steven R.

    The Department of Energy, in response to requests from the U.S. Congress, wishes to maintain an up-to-date table documenting the number of available full drawdowns of each of the caverns owned by the Strategic Petroleum Reserve. This information is important for assessing the SPR’s ability to deliver oil to domestic oil companies expeditiously if national or world events dictate a rapid sale and deployment of the oil reserves. What factors go into assessing available drawdowns? The evaluation of drawdown risks require the consideration of several factors regarding cavern and wellbore integrity and stability, including stress states caused by cavern geometrymore » and operations, salt damage caused by dilatant and tensile stresses, the effect on enhanced creep on wellbore integrity, the sympathetic stress effect of operations on neighboring caverns. Based on the work over the past several months, a consensus has been built regarding the assessment of drawdown capabilities and risks for the SPR caverns. This paper draws upon the recently West Hackberry model upgrade and analyses to reevaluate and update the available drawdowns for each of those caverns. Similar papers for the Bryan Mound, Big Hill, and Bayou Choctaw papers will be developed as the upgrades to those analyses are completed. The rationale and documentation of the methodology is described in the remainder of this report, as are the updated estimates of available drawdowns for the West Hackberry caverns.« less

  7. Relative Evaluation of the Independent Volume Measures of Caverns

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

    MUNSON,DARRELL E.

    2000-08-01

    Throughout the construction and operation of the caverns of the Strategic Petroleum Reserve (SPR), three types of cavern volume measurements have been maintained. These are: (1) the calculated solution volume determined during initial construction by solution mining and any subsequent solutioning during oil transfers, (2) the calculated sonar volume determined through sonar surveys of the cavern dimensions, and (3) the direct metering of oil to determine the volume of the cavern occupied by the oil. The objective of this study is to compare these measurements to each other and determine, if possible, the uncertainties associated with a given type ofmore » measurement. Over time, each type of measurement has acquired a customary, or an industry accepted, stated uncertainty. This uncertainty is not necessarily the result of a technical analysis. Ultimately there is one definitive quantity, the oil volume measure by the oil custody transfer meters, taken by all parties to the transfer as the correct ledger amount and for which the SPR Project is accountable. However, subsequent transfers within a site may not be with meters of the same accuracy. In this study, a very simple theory of the perfect relationship is used to evaluate the correlation (deviation) of the various measures. This theory permits separation of uncertainty and bias. Each of the four SPR sites are examined, first with comparisons between the calculated solution volumes and the sonar volumes determined during construction, then with comparisons of the oil inventories and the sonar volumes obtained either by surveying through brine prior to oil filling or through the oil directly.« less

  8. Strains and stresses in the rock around and unlined hot water cavern

    NASA Astrophysics Data System (ADS)

    Rehbinder, Göran

    1984-07-01

    Hot water stored in an unlined rock cavern is an efficient energy storage. A research program has been carried out with a test plant at the city of Avesta, Sweden. The plant consists of a rock cavern, the volume of which is 15000 m3, which serves as an energy buffer in the district heating system of the city. The water is heated from a garbage incinerator located close to the cavern. During the first test period the temperature of the stored water has varied between 40°C and 95°C. The heating of the rock causes strains and stresses in the rock. The measurements show that the state in the rock does mainly respond to the average temperature and not to the fluctuations. The maximum thermal stress is 9 MPa occurring at the wall of the cavern. The heave of the ground is less than 5 mm. The development of stress and strain will continue after the first test period since thermal equilibrium was not reached during this period.

  9. [A case of multiple cavernous angioma with dementia].

    PubMed

    Kariya, S; Kawahara, M; Suzumura, A

    2000-10-01

    We reported a 65-year-old man who developed dementia since 50 years of age. His consciousness was clear but he was indifferent to his illness. Also, the luck of attention was recognized when we underwent examinations and the result of intellectual test varied every time we performed. His memory function was almost normal on the examination which was performed when he was cooperative. Magnetic resonance imaging (MRI) disclosed multiple tiny lesions (more than 130 in all) in cerebrum, brainstem, cerebellum and spinal cord. These lesions were compatible with multiple cavernous angioma. Most of lesions manifested high-density area on cranial CT. Though the multiplicity of foci indicated the possibility of familial occurrence, he was considered to be a sporadic case on his lineage investigation and the brain MRI of his only son. In this case, neither headache nor seizures which were known as the major clinical features of intracerebral cavernous angioma was observed. He was diagnosed as having white matter dementia characterized by attentional dysfunction, decrement of volition and less memory disturbance. We speculated that he developed symptomatic dementia by the sum of multiple minor degeneration, especially in frontal lobe white matter, caused by repeated minor bleeding from cavernous angiomas.

  10. The Role of Palliative Radiosurgery When Cancer Invades the Cavernous Sinus

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

    Kano, Hideyuki; Niranjan, Ajay; Kondziolka, Douglas

    2009-03-01

    Purpose: Involvement of the cavernous sinus by direct invasion from skull base cancer or from metastatic spread of cancers is a challenging problem. We evaluated the role of stereotactic radiosurgery (SRS) in the treatment of patients who developed cavernous sinus metastases or direct invasion. Methods and Materials: We retrospectively reviewed the data from 37 patients who had cavernous sinus metastases or had cavernous sinus invasion from adjacent skull base cancers and who underwent SRS between 1992 and 2006 at University of Pittsburgh Medical Center. The median patient age was 57.8 years. Previous adjuvant management included fractionated radiotherapy in 8, chemotherapymore » in 16, and both radiotherapy and chemotherapy in 5. The primary sites of metastases or invasion were nasopharyngeal carcinoma (n = 7), parotid gland carcinoma (n = 7), and metastases from systemic cancer (n = 23). The median target volume was 6.3 cm{sup 3} (range, 0.3-33.6), and the median margin dose was 14 Gy (range, 12-20). Results: At a mean of 12.9 months (range, 0.8-63.9), 32 patients had died and 5 were living. The overall survival rate after SRS was 36.6% and 19.4% at 1 and 2 years, respectively. Progression-free survival was related to a greater marginal dose. After SRS, 12 (35.3%) of 34 patients with neurologic symptoms exhibited improvement. SRS early after diagnosis was significantly associated with improvement of cranial nerve dysfunction. Conclusion: SRS is a minimally invasive palliative option for patients whose cancer has invaded the cavernous sinus. The benefits for cranial nerve deficits are best when SRS is performed early.« less

  11. The cavernous sinus in cluster headache - a quantitative structural magnetic resonance imaging study.

    PubMed

    Arkink, Enrico B; Schoonman, Guus G; van Vliet, Jorine A; Bakels, Hannah S; Sneeboer, Marjolein Am; Haan, Joost; van Buchem, Mark A; Ferrari, Michel D; Kruit, Mark C

    2017-03-01

    Background It has been hypothesized that a constitutionally narrow cavernous sinus might predispose individuals to cluster headache. Cavernous sinus dimensions, however, have never been assessed. Methods In this case-control study, we measured the dimensions of the cavernous sinus, skull base, internal carotid and pituitary gland with high-resolution T2-weighted magnetic resonance imaging in 25 episodic, 24 chronic and 13 probable cluster headache patients, 8 chronic paroxysmal hemicrania patients and 22 headache-free controls. Dimensions were compared between groups, correcting for age, sex and transcranial diameter. Results On qualitative inspection, no relevant pathology or anatomic variants that were previously associated with cluster headache or chronic paroxysmal hemicranias were observed in the cavernous sinus or paracavernous structures. The left-to-right transcranial diameter at the temporal fossa level (mean ± SD) was larger in the headache groups (episodic cluster headache: 147.5 ± 7.3 mm, p = 0.044; chronic cluster headache: 150.2 ± 7.3 mm, p < 0.001; probable cluster headache: 146.0 ± 5.3 mm, p = 0.012; and chronic paroxysmal hemicrania: 145.2 ± 9.4 mm, p = 0.044) compared with controls (140.2 ± 8.0 mm). After adjusting for transcranial diameter and correcting for multiple comparisons, there were no differences in the dimensions of the cavernous sinus and surrounding structures between headache patients and controls. Conclusion Patients with cluster headache or chronic paroxysmal hemicrania had wider skulls than headache-free controls, but the proportional dimensions of the cavernous sinus were similar.

  12. Challenges of constructing salt cavern gas storage in China

    NASA Astrophysics Data System (ADS)

    Xia, Yan; Yuan, Guangjie; Ban, Fansheng; Zhuang, Xiaoqian; Li, Jingcui

    2017-11-01

    After more than ten years of research and engineering practice in salt cavern gas storage, the engineering technology of geology, drilling, leaching, completion, operation and monitoring system has been established. With the rapid growth of domestic consumption of natural gas, the requirement of underground gas storage is increasing. Because high-quality rock salt resources about 1000m depth are relatively scarce, the salt cavern gas storages will be built in deep rock salt. According to the current domestic conventional construction technical scheme, construction in deep salt formations will face many problems such as circulating pressure increasing, tubing blockage, deformation failure, higher completion risk and so on, caused by depth and the complex geological conditions. Considering these difficulties, the differences between current technical scheme and the construction scheme of twin well and big hole are analyzed, and the results show that the technical scheme of twin well and big hole have obvious advantages in reducing the circulating pressure loss, tubing blockage and failure risk, and they can be the alternative schemes to solve the technical difficulties of constructing salt cavern gas storages in the deep rock salt.

  13. Spontaneous subarachnoid hemorrhage due to ruptured cavernous internal carotid artery aneurysm after medical prolactinoma treatment.

    PubMed

    Khalsa, Siri Sahib; Hollon, Todd C; Shastri, Ravi; Trobe, Jonathan D; Gemmete, Joseph J; Pandey, Aditya S

    2017-03-01

    Aneurysms of the cavernous segment of the internal carotid artery (ICA) are believed to have a low risk of subarachnoid haemorrhage (SAH), given the confines of the dural rings and the anterior clinoid process. The risk may be greater when the bony and dural protection has been eroded. We report a case of spontaneous SAH from rupture of a cavernous ICA aneurysm in a patient whose large prolactinoma had markedly decreased in size as the result of cabergoline treatment. After passing a balloon test occlusion, the patient underwent successful endovascular vessel deconstruction. This case suggests that an eroding skull base lesion may distort normal anterior cranial base anatomy and allow communication between the cavernous ICA and subarachnoid space. The potential for SAH due to cavernous ICA aneurysm rupture should be recognised in patients with previous pituitary or other skull base lesions adjacent to the cavernous sinus. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  14. Modeling deformation processes of salt caverns for gas storage due to fluctuating operation pressures

    NASA Astrophysics Data System (ADS)

    Böttcher, N.; Nagel, T.; Goerke, U.; Khaledi, K.; Lins, Y.; König, D.; Schanz, T.; Köhn, D.; Attia, S.; Rabbel, W.; Bauer, S.; Kolditz, O.

    2013-12-01

    In the course of the Energy Transition in Germany, the focus of the country's energy sources is shifting from fossil to renewable and sustainable energy carriers. Since renewable energy sources, such as wind and solar power, are subjected to annual, seasonal, and diurnal fluctuations, the development and extension of energy storage capacities is a priority in German R&D programs. Common methods of energy storage are the utilization of subsurface caverns as a reservoir for natural or artificial fuel gases, such as hydrogen, methane, or the storage of compressed air. The construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to the possibility of solution mining. Another advantage of evaporite as a host material is the self-healing capacity of salt rock. Gas caverns are capable of short-term energy storage (hours to days), so the operating pressures inside the caverns are fluctuating periodically with a high number of cycles. This work investigates the influence of fluctuating operation pressures on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. Our simulations include the thermodynamic behaviour of the gas during the loading/ unloading of the cavern. This provides information on the transient pressure and temperature distribution on the cavern boundary to calculate the deformation of its geometry. Non-linear material models are used for the mechanical analysis, which describe the creep and self-healing behavior of the salt rock under fluctuating loading pressures. In order to identify the necessary material parameters, we perform experimental studies on the mechanical behaviour of salt rock under varying pressure and temperature conditions. Based on the numerical results, we further derive concepts for monitoring THM quantities in the

  15. Congenital Arteriovenous Malformation of the Scalp Involving the Orbit.

    PubMed

    Feletti, Alberto; Dimitriadis, Stavros; Vallone, Stefano; Pavesi, Giacomo

    2018-06-15

     Arteriovenous malformations (AVMs) of the scalp are rare and infrequently encountered by the neurosurgeon.  We report a unique case of a 42-year-old patient who presented with a progressive worsening of visual acuity in the right eye (lower quadrantanopia) and palpebral ptosis. Physical examination revealed a right exophthalmos and a right frontoparietal scalp soft swelling when the patient was in the supine position. Neurologic work-up showed a scalp AVM extending into the orbit and connected to an intraorbital cavernous angioma. The patient was treated with a frontotemporal craniotomy and decompression of the orbit.  In the rare case of intraorbital extension of a scalp AVM, neurologic symptoms may appear when the size of the vascular malformation increases with age. The aims of surgery should be decompression of the orbit and aesthetic preservation, rather than complete excision. A review of the literature is also provided. Georg Thieme Verlag KG Stuttgart · New York.

  16. Endoscope-assisted resection of cavernous angioma at the foramen of Monro: a case report.

    PubMed

    Matsumoto, Yuji; Kurozumi, Kazuhiko; Shimazu, Yousuke; Ichikawa, Tomotsugu; Date, Isao

    2016-01-01

    Intraventricular cavernous angiomas are rare pathological entities, and those located at the foramen of Monro are even rarer. We herein present a case of cavernous angioma at the foramen of Monro that was successfully treated by neuroendoscope-assisted surgical removal, and review the relevant literature. A 65-year-old woman had experienced headache and vomiting for 10 days before admission to another hospital. Magnetic resonance imaging (MRI) showed a mass at the foramen of Monro, and obstructive hydrocephalus of both lateral ventricles. The patient was then referred to our hospital. Neurological examination on admission to our hospital showed memory disturbance (Mini-Mental State Examination 20/30) and wide-based gait. A cavernous angioma at the foramen of Monro was diagnosed based on the typical popcorn-like appearance of the lesion on MRI. The lesion was completely removed by neuroendoscope-assisted transcortical surgery with the Viewsite Brain Access System (Vycor Medical Inc., Boca Raton, FL), leading to a reduction in the size of the ventricles. The resected mass was histologically confirmed to be cavernous angioma. The patient's symptoms resolved immediately and there were no postoperative complications. Minimally invasive neuroendoscope-assisted surgery was used to successfully treat a cavernous angioma at the foramen of Monro.

  17. Operative management of brainstem cavernous malformations.

    PubMed

    Asaad, Wael F; Walcott, Brian P; Nahed, Brian V; Ogilvy, Christopher S

    2010-09-01

    Brainstem cavernous malformations (CMs) are complex lesions associated with hemorrhage and neurological deficit. In this review, the authors describe the anatomical nuances relating to the operative techniques for these challenging lesions. The resection of brainstem CMs in properly selected patients has been demonstrated to reduce the risk of rehemorrhage and can be achieved relatively safely in experienced hands.

  18. Endoscopic endonasal approach to the anteromedial temporal fossa and mobilization of the lateral wall of the cavernous sinus through the inferior orbital fissure and V1-V2 corridor: An anatomical study and clinical considerations.

    PubMed

    Hanakita, Shunya; Chang, Wei-Chieh; Watanabe, Kentaro; Ronconi, Daniel; Labidi, Moujahed; Park, Hun-Ho; Oyama, Kenichi; Bernat, Anne-Laure; Froelich, Sebastien

    2018-04-27

    The aim of this study was to identify key anatomical landmarks useful in gaining access to the anteromedial temporal region via the corridor formed by the inferior orbital fissure (IOF), the ophthalmic branch (V1), and the maxillary branch (V2) of the trigeminal nerve via the EEA. An anatomical dissection of six cadaver heads was performed to confirm the feasibility and applicability of the EEA for accessing the anteromedial temporal region. Following middle turbinectomy, the lateral recess of the sphenoid sinus was opened, the orbital apex exposed, and the posterior wall of the maxillary sinus was removed, in sequence. The IOF and the pterygopalatine fossa (PPF) were then identified. After opening the foramen rotundum (FR) and removing the bony structure between the FR, V2 was transposed downward. The orbital muscle of Müller was removed. The PPF was mobilized downward exposing the greater wing of the sphenoid bone (GWS). The GWS between V1 and V2 was drilled, thus exposing the temporal dura. With blunt dissection, the medial temporal dura was peeled away from the cavernous sinus (CS) in order to increase access to the anteromedial temporal region. In this study, the anteromedial temporal fossa was exposed by drilling the V1-V2 triangle corridor via the EEA. Endoscopic endonasal exposure of the anteromedial temporal fossa is feasible and requires limited endonasal work. This approach may be considered as an alternate surgical corridor to the temporomesial lobe that offers the advantages of a direct route with less temporal lobe retraction. Copyright © 2018. Published by Elsevier Inc.

  19. Cavernous carotid aneurysms in the era of flow diversion: a need to revisit treatment paradigms.

    PubMed

    Tanweer, O; Raz, E; Brunswick, A; Zumofen, D; Shapiro, M; Riina, H A; Fouladvand, M; Becske, T; Nelson, P K

    2014-12-01

    Recent techniques of endoluminal reconstruction with flow-diverting stents have not been incorporated into treatment algorithms for cavernous carotid aneurysms. This study examines the authors' institutional experience and a systematic review of the literature for outcomes and complications using the Pipeline Embolization Device in unruptured cavernous carotid aneurysms. A retrospective search for cavernous carotid aneurysms from a prospectively collected data base of aneurysms treated with the Pipeline Embolization Device at our institution was performed. Baseline demographic, clinical, and laboratory values; intrainterventional data; and data at all follow-up visits were collected. A systematic review of the literature for complication data was performed with inquiries sent when clarification of data was needed. Forty-three cavernous carotid aneurysms were included in the study. Our mean radiographic follow-up was 2.05 years. On last follow-up, 88.4% of the aneurysms treated had complete or near-complete occlusion. Aneurysm complete or near-complete occlusion rates at 6 months, 12 months, and 36 months were 81.4%, 89.7%, and 100%, respectively. Of patients with neuro-ophthalmologic deficits on presentation, 84.2% had improvement in their visual symptoms. Overall, we had a 0% mortality rate and a 2.3% major neurologic complication rate. Our systematic review of the literature yielded 227 cavernous carotid aneurysms treated with the Pipeline Embolization Device with mortality and morbidity rates of 0.4% and 3.1%, respectively. Endoluminal reconstruction with flow diversion for large unruptured cavernous carotid aneurysms can yield high efficacy with low complications. Further long-term data will be helpful in assessing the durability of the cure; however, we advocate a revisiting of current management paradigms for cavernous carotid aneurysms. © 2014 by American Journal of Neuroradiology.

  20. Effects of hyperglycemia on rat cavernous nerve axons: a functional and ultrastructural study.

    PubMed

    Zotova, Elena G; Schaumburg, Herbert H; Raine, Cedric S; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C

    2008-10-01

    The present study explored parallel changes in the physiology and structure of myelinated (Adelta) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (< 2.5 m/s). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy.

  1. EFFECTS OF HYPERGLYCEMIA ON RAT CAVERNOUS NERVE AXONS: A FUNCTIONAL AND ULTRASTRUCTURAL STUDY

    PubMed Central

    Zotova, Elena G.; Schaumburg, Herbert H.; Raine, Cedric S.; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C.

    2008-01-01

    The present study explored parallel changes in the physiology and structure of myelinated (Aδ) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (<2.5 m/sec). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy. PMID:18687329

  2. Multiple cavernous malformations presenting in a patient with Poland syndrome: A case report

    PubMed Central

    2011-01-01

    Introduction Poland syndrome is a congenital disorder related to chest and hand anomalies on one side of the body. Its etiology remains unclear, with an ipsilateral vascular alteration (of unknown origin) to the subclavian artery in early embryogenesis being the currently accepted theory. Cavernous malformations are vascular hamartomas, which have been linked to a genetic etiology, particularly in familial cases, which commonly present with multiple lesions. Our case report is the first to describe multiple cavernous malformations associated with Poland syndrome, further supporting the vascular etiology theory, but pointing to a genetic rather than a mechanistic factor disrupting blood flow in the corresponding vessels. Case presentation A 41-year-old Caucasian man with Poland syndrome on the right side of his body presented to our hospital with a secondary generalized seizure and was found to have multiple cavernous malformations distributed in his brain, cerebellum, and brain stem, with a predominance of lesions in the left hemisphere. Conclusion The distribution of cavernous malformations in the left hemisphere and the right-sided Poland syndrome in our patient could not be explained by a mechanistic disruption of one of the subclavian arteries. A genetic alteration, as in familial cavernous malformations, would be a more appropriate etiologic diagnosis of Poland syndrome in our patient. Further genetic and pathological studies of the involved blood vessels in patients with Poland syndrome could lead to a better understanding of the disease. PMID:21933407

  3. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 4, West Hackberry site, Louisiana.

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

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-09-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 4 focuses on the West Hackberry SPR site, located in southwestern Louisiana. Volumes 1, 2, and 3, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Big Hill SPR site, Texas, and the Bryan Mound SPR site, Texas. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes,more » the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.« less

  4. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 2, Big Hill Site, Texas.

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

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-08-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 2 focuses on the Big Hill SPR site, located in southeastern Texas. Volumes 1, 3, and 4, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes,more » the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.« less

  5. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 1, Bayou Choctaw site, Louisiana.

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

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-10-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 1 focuses on the Bayou Choctaw SPR site, located in southern Louisiana. Volumes 2, 3, and 4, respectively, present images for the Big Hill SPR site, Texas, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes,more » the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.« less

  6. Spinal extradural cavernous haemangioma in an elderly man

    PubMed Central

    Rahman, Asifur; Hoque, Saif Ul; Bhandari, Paawan Bahadur; Abu Obaida, Abu Saleh Md

    2012-01-01

    Cavernous haemangiomas are vascular malformations that may affect any part of the central nervous system. Epidural haemangiomas are rare and constitute ∼4% of all epidural tumours and 12% of all intraspinal haemangiomas. These tumours enlarge slowly and produce symptoms of progressive myelopathy or radiculopathy or both. History, clinical examination, routine radiographs, MRI and histopathological studies are the aids for a definitive diagnosis. Surgery can give a very beneficial result with good functional and neurological improvement. Chance of recurrence is less after a good surgical removal. Here we present a case of spinal extradural cavernous haemangioma in a 65- year-old man who had a good functional and neurological recovery after surgery. At 9 months postoperative follow-up, he did well without any new problems with regard to recurrence. We report this case for its rarity. PMID:22878996

  7. Detection of cavernous transformation of the portal vein by contrast-enhanced ultrasound.

    PubMed

    Hwang, Misun; Thimm, Matthew A; Guerrerio, Anthony L

    2018-06-01

    Cavernous transformation of the portal vein can be missed on color Doppler exam or arterial phase cross-sectional imaging due to their slow flow and delayed enhancement. Contrast-enhanced ultrasound (CEUS) offers many advantages over other imaging techniques and can be used to successfully detect cavernous transformations of the portal vein. A 10-month-old female was followed for repeat episodes of hematemesis. Computed tomography angiography (CTA) and magnetic resonance arteriogram (MRA) and portal venography were performed. Color Doppler exam of the portal vein was performed followed by administration of Lumason, a microbubble US contrast agent. Magnetic resonance arteriogram, CTA, and color Doppler exam at the time of initial presentation was unremarkable without obvious vascular malformation within the limits of motion degraded exam. At 8-month follow-up, esophagogastroduodenoscopy revealed a vascular malformation in the distal esophagus which was sclerosed. At 6 month after sclerosis of the lesion, portal venography revealed occlusion of the portal vein with extensive collateralization. Color Doppler revealed subtle hyperarterialization and periportal collaterals. CEUS following color Doppler exam demonstrated extensive enhancement of periportal collaterals. Repeat color Doppler after contrast administration demonstrated extensive Doppler signal in the collateral vessels, suggestive of cavernous transformation. We describe a case of cavernous transformation of the portal vein missed on initial color Doppler, CTA and MRA, but detected with contrast-enhanced ultrasound technique.

  8. Derivation and application of an analytical rock displacement solution on rectangular cavern wall using the inverse mapping method.

    PubMed

    Gao, Mingzhong; Yu, Bin; Qiu, Zhiqiang; Yin, Xiangang; Li, Shengwei; Liu, Qiang

    2017-01-01

    Rectangular caverns are increasingly used in underground engineering projects, the failure mechanism of rectangular cavern wall rock is significantly different as a result of the cross-sectional shape and variations in wall stress distributions. However, the conventional computational method always results in a long-winded computational process and multiple displacement solutions of internal rectangular wall rock. This paper uses a Laurent series complex method to obtain a mapping function expression based on complex variable function theory and conformal transformation. This method is combined with the Schwarz-Christoffel method to calculate the mapping function coefficient and to determine the rectangular cavern wall rock deformation. With regard to the inverse mapping concept, the mapping relation between the polar coordinate system within plane ς and a corresponding unique plane coordinate point inside the cavern wall rock is discussed. The disadvantage of multiple solutions when mapping from the plane to the polar coordinate system is addressed. This theoretical formula is used to calculate wall rock boundary deformation and displacement field nephograms inside the wall rock for a given cavern height and width. A comparison with ANSYS numerical software results suggests that the theoretical solution and numerical solution exhibit identical trends, thereby demonstrating the method's validity. This method greatly improves the computing accuracy and reduces the difficulty in solving for cavern boundary and internal wall rock displacements. The proposed method provides a theoretical guide for controlling cavern wall rock deformation failure.

  9. Derivation and application of an analytical rock displacement solution on rectangular cavern wall using the inverse mapping method

    PubMed Central

    Gao, Mingzhong; Qiu, Zhiqiang; Yin, Xiangang; Li, Shengwei; Liu, Qiang

    2017-01-01

    Rectangular caverns are increasingly used in underground engineering projects, the failure mechanism of rectangular cavern wall rock is significantly different as a result of the cross-sectional shape and variations in wall stress distributions. However, the conventional computational method always results in a long-winded computational process and multiple displacement solutions of internal rectangular wall rock. This paper uses a Laurent series complex method to obtain a mapping function expression based on complex variable function theory and conformal transformation. This method is combined with the Schwarz-Christoffel method to calculate the mapping function coefficient and to determine the rectangular cavern wall rock deformation. With regard to the inverse mapping concept, the mapping relation between the polar coordinate system within plane ς and a corresponding unique plane coordinate point inside the cavern wall rock is discussed. The disadvantage of multiple solutions when mapping from the plane to the polar coordinate system is addressed. This theoretical formula is used to calculate wall rock boundary deformation and displacement field nephograms inside the wall rock for a given cavern height and width. A comparison with ANSYS numerical software results suggests that the theoretical solution and numerical solution exhibit identical trends, thereby demonstrating the method’s validity. This method greatly improves the computing accuracy and reduces the difficulty in solving for cavern boundary and internal wall rock displacements. The proposed method provides a theoretical guide for controlling cavern wall rock deformation failure. PMID:29155892

  10. Fractionated Proton Radiotherapy for Benign Cavernous Sinus Meningiomas

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

    Slater, Jerry D., E-mail: jdslater@dominion.llumc.edu; Loredo, Lilia N.; Chung, Arthur

    2012-08-01

    Purpose: To evaluate the efficacy of fractionated proton radiotherapy for a population of patients with benign cavernous sinus meningiomas. Methods and Materials: Between 1991 and 2002, 72 patients were treated at Loma Linda University Medical Center with proton therapy for cavernous sinus meningiomas. Fifty-one patients had biopsy or subtotal resection; 47 had World Health Organization grade 1 pathology. Twenty-one patients had no histologic verification. Twenty-two patients received primary proton therapy; 30 had 1 previous surgery; 20 had more than 1 surgery. The mean gross tumor volume was 27.6 cm{sup 3}; mean clinical target volume was 52.9 cm{sup 3}. Median totalmore » doses for patients with and without histologic verification were 59 and 57 Gy, respectively. Mean and median follow-up periods were 74 months. Results: The overall 5-year actuarial control rate was 96%; the control rate was 99% in patients with grade 1 or absent histologic findings and 50% for those with atypical histology. All 21 patients who did not have histologic verification and 46 of 47 patients with histologic confirmation of grade 1 tumor demonstrated disease control at 5 years. Control rates for patients without previous surgery, 1 surgery, and 2 or more surgeries were 95%, 96%, and 95%, respectively. Conclusions: Fractionated proton radiotherapy for grade 1 cavernous sinus meningiomas achieves excellent control rates with minimal toxicities, regardless of surgical intervention or use of histologic diagnosis. Disease control for large lesions can be achieved by primary fractionated proton therapy.« less

  11. Effect of chronic low-dose tadalafil on penile cavernous tissues in diabetic rats.

    PubMed

    Mostafa, Mohamed E; Senbel, Amira M; Mostafa, Taymour

    2013-06-01

    To assess the effect of chronic low-dose administration of tadalafil (Td) on penile cavernous tissue in induced diabetic rats. The study investigaged 48 adult male albino rats, comprising a control group, sham controls, streptozotocin-induced diabetic rats, and induced diabetic rats that received Td low-dose daily (0.09 mg/200 g weight) for 2 months. The rats were euthanized 1 day after the last dose. Cavernous tissues were subjected to histologic, immunohistochemical, morphometric studies, and measurement of intracavernosal pressure and mean arterial pressure in anesthetized rats. Diabetic rats demonstrated dilated cavernous spaces, smooth muscles with heterochromatic nuclei, degenerated mitochondria, vacuolated cytoplasm, and negative smooth muscle immunoreactivity. Nerve fibers demonstrated a thick myelin sheath and intra-axonal edema, where blood capillaries exhibited thick basement membrane. Diabetic rats on Td showed improved cavernous organization with significant morphometric increases in the area percentage of smooth muscles and elastic tissue and a significant decrease of fibrous tissue. The Td-treated group showed enhanced erectile function (intracavernosal pressure/mean arterial pressure) at 0.3, 0.5, 1, 3, and 5 Hz compared with diabetic group values at the respective frequencies (P <.05) that approached control values. Chronic low-dose administration of Td in diabetic rats is associated with substantial improvement of the structure of penile cavernous tissue, with increased smooth muscles and elastic tissue, decreased fibrous tissue, and functional enhancement of the erectile function. This raises the idea that the change in penile architecture with Td treatment improves erectile function beyond its half-life and its direct pharmacologic action on phosphodiesterase type 5. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Cavernous Transformation of Portal Vein Secondary to Portal Vein Thrombosis: A Case Report

    PubMed Central

    Ramos, Radhames; Park, Yoojin; Shazad, Ghulamullah; A.Garcia, Christine; Cohen, Ronny

    2012-01-01

    There are few reported cases of cavernous transformation of the portal vein (CTPV) in adults. We present a case of a 58 year-old male who was found to have this complication due to portal vein thrombosis (PVT). A 58-year old African American male with chronic alcohol and tobacco use presented with a 25-day history of weakness, generalized malaise, nausea and vomiting associated with progressively worsening anorexia and weight loss. The patient was admitted for severe anemia in conjunction with abnormal liver function tests and electrolyte abnormalities, and to rule out end stage liver disease or hepatic malignancy. The work-up for anemia showed no significant colon abnormalities, cholecystitis, liver cirrhosis, or liver abnormalities but could not rule out malignancy. An esophageogastroduodenoscopy (EGD) was suspicious for a mass compressing the stomach and small bowel. After further work-up, the hepatic mass has been diagnosed as a cavernous transformation of the portal vein (CTPV), a very rare complication of portal vein thrombosis (PVT). Cavernous Transformation of the Portal Vein (CTPV) is a rare and incurable complication of portal vein thrombosis (PVT) that should be considered as one of the differential diagnoses of a hepatic mass. Keywords Cavernous transformation of the portal vein; Portal vein thrombosis; Portal hypertension; Hyperbilirubinemia; Hepatic mass PMID:22383935

  13. Failure Analysis of Overhanging Blocks in the Walls of a Gas Storage Salt Cavern: A Case Study

    NASA Astrophysics Data System (ADS)

    Wang, Tongtao; Yang, Chunhe; Li, Jianjun; Li, Jinlong; Shi, Xilin; Ma, Hongling

    2017-01-01

    Most of the rock salt of China is bedded, in which non-salt layers and rock salt layers alternate. Due to the poor solubility of the non-salt layers, many blocks overhang on the walls of the caverns used for gas storage, constructed by water leaching. These overhanging blocks may collapse at any time, which may damage the tubing and casing string, and even cause instability of the cavern. They are one of the main factors threatening the safety of caverns excavated in bedded rock salt formations. In this paper, a geomechanical model of the JJKK-D salt cavern, located in Jintan salt district, Jintan city, Jiangsu province, China, is established to evaluate the stability of the overhanging blocks on its walls. The characters of the target formation, property parameters of the rock mass, and actual working conditions are considered in the geomechanical model. An index system composed of stress, displacement, plastic zone, safety factor, and equivalent strain is used to predict the collapse length of the overhanging blocks, the moment the collapse will take place, and the main factors causing the collapse. The sonar survey data of the JJKK-D salt cavern are used to verify the reliability and accuracy of the proposed geomechanical model. The results show that the proposed geomechanical model has a good reliability and accuracy, and can be used for the collapse prediction of the overhanging blocks on the wall of the JJKK-D salt cavern. The collapse length of the overhanging block is about 8 m. We conclude that the collapse takes place during the debrining. The reason behind the collapse is the sudden decrease of the fluid density, leading to the increase of the self-weight of the overhanging blocks. This study provides a basis for the collapse prediction method of the overhanging blocks of Jintan salt cavern gas storage, and can also serve as a reference for salt cavern gas storage with similar conditions to deal with overhanging blocks.

  14. A creative therapy in treating cavernous hemangioma of penis with copper wire.

    PubMed

    Zhang, Dong; Zhang, Haiyang; Sun, Peng; Li, Peng; Xue, Aibing; Jin, Xunbo

    2014-10-01

    Cavernous hemangiomas of penis are rare benign lesions infrequently described in the literature. No completely satisfactory treatment has been found to correct the cosmetic deformities especially the extensive hemangiomas of corpus penis. In light of the promising application of copper wire/needle in vascular malformations, we began a clinical study to investigate the safety, feasibility, and cosmetic effect of copper wire therapy in treating cavernous hemangioma of penis. Seven patients ranging in age from 12 to 32 years with penile cavernous hemangiomas entered our study from 2005 to 2011. All patients received treatments with percutaneous copper wires. Perioperative data including mean operation time, estimated blood loss, length of copper wire retention, and length of hospital stay were analyzed. All possible complications were noted, and cosmetic result was evaluated. Patients were followed up after discharge from the hospital. All operations were successful, and no obvious complications were observed. The patients were satisfied with the aesthetic results. Follow-up time ranged from 1 to 5 years. Recurrence was discovered in a patient with the largest lesion of corpus penis 2 months after the treatment. Secondary procedure was carried out with the same technique, and no lesions were found later. The shortage of studies on this topic prevented us from defining a therapeutic reference standard. The results of our study confirmed that copper wire therapy was a simple, safe, and useful option for penile cavernous hemangioma. © 2013 International Society for Sexual Medicine.

  15. Extranodal natural killer/T-cell lymphoma presenting as orbital cellulitis

    PubMed Central

    Zuhaimy, Hanis; Aziz, Hayati Abdul; Vasudevan, Suresh; Hui Hui, Siah

    2017-01-01

    Objective: To report an aggressive case of extranodal natural killer/T-cell lymphoma (NKTCL) of the ethmoid sinus presenting as orbital cellulitis Method: Case report Results: A 56-year-old male presented with right eye redness, reduced vision, and periorbital swelling for 5 weeks duration associated with a two-month history of blocked nose. The visual acuity of the right eye was 6/18. The eye was proptosed with periorbital oedema and conjunctival chemosis. The pupil was mid-dilated but there was no relative afferent pupillary defect. The fundus was normal. The extraocular movements were restricted in all directions of gaze. Nasal endoscopy revealed pansinusitis that corresponded with CT scan orbit and paranasal sinuses findings. Despite treatment, he showed no clinical improvement. Ethmoidal sinus biopsies performed revealed extranodal NKTCL. Further imaging showed involvement of the right orbital contents and its adnexa with intracranial extension into the right cavernous sinus and meninges over right temporal fossa. The patient underwent chemotherapy. However he succumbed to his illness two months after the diagnosis. Conclusion: Extranodal NKTCL is a great mimicker. This case demonstrated how an acute initial presentation of extranodal NKTCL can present as orbital cellulitis with pansinusitis. PMID:28194321

  16. Speckle reduction during all-fiber common-path optical coherence tomography of the cavernous nerves

    NASA Astrophysics Data System (ADS)

    Chitchian, Shahab; Fiddy, Michael; Fried, Nathaniel M.

    2009-02-01

    Improvements in identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery, which are responsible for erectile function, may improve nerve preservation and postoperative sexual potency. In this study, we use a rat prostate, ex vivo, to evaluate the feasibility of optical coherence tomography (OCT) as a diagnostic tool for real-time imaging and identification of the cavernous nerves. A novel OCT system based on an all single-mode fiber common-path interferometer-based scanning system is used for this purpose. A wavelet shrinkage denoising technique using Stein's unbiased risk estimator (SURE) algorithm to calculate a data-adaptive threshold is implemented for speckle noise reduction in the OCT image. The signal-to-noise ratio (SNR) was improved by 9 dB and the image quality metrics of the cavernous nerves also improved significantly.

  17. Benign orbital apex tumors treated with multisession gamma knife radiosurgery.

    PubMed

    Goh, Alice Siew Ching; Kim, Yoon-Duck; Woo, Kyung In; Lee, Jung-Il

    2013-03-01

    The orbital apex is an important anatomic landmark that hosts numerous critical neurovascular structures. Tumor resection performed at this complex region poses a therapeutic challenge to orbital surgeons and often is associated with significant visual morbidity. This article reports the efficacy and safety of multisession gamma knife radiosurgery (GKRS) in benign, well-circumscribed tumors located at the orbital apex. Retrospective interventional case series. Five patients with visual disturbances resulting from a benign, well-circumscribed orbital apex tumor (3 cases of cavernous hemangioma and 2 cases of schwannoma). Each patient treated with GKRS with a total radiation dose of 20 Gy in 4 sessions (5 Gy in each session with an isodose line of 50%) delivered to the tumor margin. Best-corrected visual acuity, visual field changes, orbital imaging, tumor growth control, and side effects of radiation. All patients demonstrated improvement in visual acuity, pupillary responses, color vision, and visual field. Tumor shrinkage was observed in all patients and remained stable until the last follow-up. No adverse events were noted during or after the radiosurgery. None of the patients experienced any radiation-related ocular morbidity. From this experience, multisession GKRS seems to be an effective management strategy to treat solitary, benign, well-circumscribed orbital apex tumors. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  18. Deep Fracturing of the Hard Rock Surrounding a Large Underground Cavern Subjected to High Geostress: In Situ Observation and Mechanism Analysis

    NASA Astrophysics Data System (ADS)

    Feng, Xia-Ting; Pei, Shu-Feng; Jiang, Quan; Zhou, Yang-Yi; Li, Shao-Jun; Yao, Zhi-Bin

    2017-08-01

    Rocks that are far removed from caverns or tunnels peripheries and subjected to high geostress may undergo `deep fracturing'. Deep fracturing of hard rock can cause serious hazards that cause delays and increase the cost of construction of underground caverns with high sidewalls and large spans (especially when subjected to high geostress). To extensively investigate the mechanism responsible for deep fracturing, and the relationship between fracturing and the excavation & support of caverns, this paper presents a basic procedure for making in situ observations on the deep fracturing process in hard rock. The basic procedure involves predicting the stress concentration zones in the surrounding rocks of caverns induced by excavation using geomechanical techniques. Boreholes are then drilled through these stress concentration zones from pre-existing tunnels (such as auxiliary galleries) toward the caverns before its excavation. Continuous observations of the fracturing of the surrounding rocks are performed during excavation using a borehole camera in the boreholes in order to analyze the evolution of the fracturing process. The deep fracturing observed in a large underground cavern (high sidewalls and large span) in southwest China excavated in basalt under high geostress is also discussed. By continuously observing the hard rock surrounding the arch on the upstream side of the cavern during the excavation of the first three layers, it was observed that the fracturing developed into the surrounding rocks with downward excavation of the cavern. Fracturing was found at distances up to 8-9 m from the cavern periphery during the excavation of Layer III. Also, the cracks propagated along pre-existing joints or at the interfaces between quartz porphyry and the rock matrix. The relationship between deep fracturing of the surrounding rocks and the advance of the cavern working faces was analyzed during excavation of Layer Ib. The results indicate that the extent of the

  19. Numerical study on criteria for design and operation of water curtain system in underground oil storage cavern using site descriptive fracture networks

    NASA Astrophysics Data System (ADS)

    Moon, Jiwon; Yeo, In Wook

    2013-04-01

    Underground unlined caverns have been constructed in fractured rocks to stockpile oil and petroleum products, where they are hydraulically contained by natural groundwater pressure. However, for the case that natural groundwater pressure is not maintained at the required level, water curtain boreholes, through which water is injected, are often constructed above the cavern as engineering barrier to secure water pressure enough to overwhelm the operational pressure of the cavern. For secure containment of oil and petroleum products inside the cavern, it is essential to keep water pressure around the cavern higher than operational pressure of the cavern using either natural groundwater pressure or engineering barrier. In the Republic of Korea, a number of underground stockpile bases are being operated by Korea National Oil Corporation (KNOC) and private companies, most of which have water curtain system. The criterion that KNOC adopts for water curtain system design and operation such as the vertical distance from the cavern and operational injection rate is based on the Åberg hypothesis that the vertical hydraulic gradient should be larger than one. The criterion has been used for maintaining oil storage cavern without its thorough review. In this study, systematic numerical works have been done for reviewing the Åberg criterion. As groundwater predominantly takes places through fractures in underground caverns, discrete fracture modeling approach is essential for this study. Fracture data, obtained from boreholes drilled at the stage of site investigation at the Yeosu stockpile base in Korea, were statistically analyzed in terms of orientation and intensity, which were used to generate the site descriptive three dimensional fracture networks. Then, groundwater flow modeling has been carried out for the fracture networks. Constant head boundaries were applied along the circumference of the cavern and water curtain boreholes. Main flow channel and hydraulic

  20. Pure Spinal Epidural Cavernous Hemangioma with Intralesional Hemorrhage: A Rare Cause of Thoracic Myelopathy

    PubMed Central

    Jang, Donghwan; Kim, Choonghyo; Lee, Seung Jin; Ryu, Young-Joon

    2014-01-01

    Although cavernous hemangiomas occur frequently in the intracranial structures, they are rare in the spine. Most of spinal hemangiomas are vertebral origin and "pure" epidural hemangiomas not originating from the vertebral bone are very rare. Our spinal hemangioma case is extremely rare because of its "pure" epidural involvement and intralesional hemorrhage. A 64-year-old man presented with progressive paraparesis from two months ago. His motor weakness was rated as grade 4/5 in bilateral lower extremities. He also complained of decreased sensation below the T4 sensory dermatome, which continuously progressed to the higher dermatome level. Magnetic resonance imaging demonstrated thoracic spinal tumor at T3-T4 level. The tumor was located epidural space compressing thoracic spinal cord ventrally. The tumor was not involved with the thoracic vertebral bone. We performed T3-5 laminectomy and removed the tumor completely. The tumor was not infiltrating into intradural space or vertebral bone. The histopathologic study confirmed the epidural tumor as cavernous hemangioma. Postoperatively, his weakness improved gradually. Four months later, his paraparesis recovered completely. Here, we present a case of pure spinal epidural cavernous hemangioma, which has intralesional hemorrhage. We believe cavernous hemangioma should be included in the differential diagnosis of the spinal epidural tumors. PMID:25110490

  1. Results of stereotactic radiosurgery for patients with imaging defined cavernous sinus meningiomas

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

    Pollock, Bruce E.; Stafford, Scott L.

    2005-08-01

    Introduction: The purpose of this study was to evaluate the efficacy and safety of stereotactic radiosurgery as primary management for patients with imaging defined cavernous sinus meningiomas. Methods: Between 1992 and 2001, 49 patients had radiosurgery for dural-based masses of the cavernous sinus presumed to be meningiomas. The mean patient age was 55.5 years. The mean tumor volume was 10.2 mL; the mean tumor margin dose was 15.9 Gy. The mean follow-up was 58 months (range, 16-144 months). Results: No tumor enlarged after radiosurgery. Twelve of 38 patients (26%) with preexisting diplopia or facial numbness/pain had improvement in cranial nervemore » function. Five patients (10%) had new (n = 3) or worsened (n = 2) trigeminal dysfunction; 2 of these patients (4%) underwent surgery at 20 and 25 months after radiosurgery despite no evidence of tumor progression. Neither patient improved after partial tumor resection. One patient (2%) developed an oculomotor nerve injury. One patient (2%) had an ischemic stroke related to occlusion of the cavernous segment of the internal carotid artery. Event-free survival was 98%, 85%, and 80% at 1, 3, and 7 years after radiosurgery, respectively. Univariate analysis of patient and dosimetric factors found no analyzed factor correlated with postradiosurgical morbidity. Conclusions: Radiosurgery was an effective primary management strategy for patients with an imaging defined cavernous sinus meningioma. Except in situations of symptomatic mass effect, unusual clinical presentation, or atypical imaging features, surgery to confirm the histologic diagnosis is unlikely to provide clinical benefit.« less

  2. Cataract surgery in a case of carotid cavernous fistula

    PubMed Central

    Nair, Akshay Gopinathan; Praveen, Smita Vittal; Noronha, Veena Olma

    2014-01-01

    A carotid-cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system. The ocular manifestations include conjunctival chemosis, proptosis, globe displacement, raised intraocular pressure and optic neuropathy. Although management of CCF in these patients is necessary, the ophthalmologist may also have to treat other ocular morbidities such as cataract. Cataract surgery in patients with CCF may be associated with many possible complications, including suprachoroidal hemorrhage. We describe cataract extraction surgery in 60-year-old female with bilateral spontaneous low-flow CCF. She underwent phacoemulsification via a clear corneal route under topical anesthesia and had an uneventful postoperative phase and recovered successfully. Given the various possible ocular changes in CCF, one must proceed with an intraocular surgery with caution. In this communication, we wish to describe the surgical precautions and the possible pitfalls in cataract surgery in patients with CCF. PMID:25370401

  3. Submarine groundwater discharge into the coast revealed by water chemistry of man-made undersea liquefied petroleum gas cavern

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Yong; Cho, Byung Wook

    2008-10-01

    SummaryThe occurrence of submarine groundwater discharge (SGD) as well as its supply of many nutrients and metals to coastal seawaters is now generally known. However, previous studies have focused on the chemical and radiological analysis of groundwater, surface seawater, shallow marine sediments and their pore waters, as well as the measurement of upward flow through the marine sediments, as end members of the discharge process. In this study, chemical and isotopic analysis results of marine subsurface waters are reported. These were obtained from deep boreholes of an undersea liquefied petroleum gas (LPG) storage cavern, located about 8 km off the western coast of Korea. The cavern is about 130-150 m below the sea bottom, which is covered by a 4.8-19.5 m silty clay stratum. An isotopic composition (δ 2H and δ 18O) of the marine subsurface waters falls on a mixing line between terrestrial groundwater and seawater. Vertical EC profiling at the cavern boreholes revealed the existence of a fresh water zone. An increase in the contents of ferrous iron and manganese and a decrease in levels of nitrate, bicarbonate and cavern seepage were recorded in August 2006, indicating a decreased submarine groundwater flux originating from land, mainly caused by an elevated cavern gas pressure. It is suggested in this study that the main source of fresh waters in the man-made undersea cavern is the submarine groundwater discharge mainly originating from the land.

  4. Phase II Study to Assess the Efficacy of Hypofractionated Stereotactic Radiotherapy in Patients With Large Cavernous Sinus Hemangiomas

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

    Wang Xin; Liu Xiaoxia; Mei Guanghai

    Purpose: Cavernous sinus hemangioma is a rare vascular tumor. The direct microsurgical approach usually results in massive hemorrhage. Although radiosurgery plays an important role in managing cavernous sinus hemangiomas as a treatment alternative to microsurgery, the potential for increased toxicity with single-session treatment of large tumors is a concern. The purpose of this study was to assess the efficacy of hypofractionated stereotactic radiotherapy in patients with large cavernous sinus hemangiomas. Methods: Fourteen patients with large (volume >20 cm{sup 3}) cavernous sinus hemangiomas were enrolled in a prospective Phase II study between December 2007 and December 2010. The hypofractionated stereotactic radiotherapymore » dose was 21 Gy delivered in 3 fractions. Results: After a mean follow-up of 15 months (range, 6-36 months), the magnetic resonance images showed a mean of 77% tumor volume reduction (range, 44-99%). Among the 6 patients with cranial nerve impairments before hypofractionated stereotactic radiotherapy, 1 achieved symptomatic complete resolution and 5 had improvement. No radiotherapy-related complications were observed during follow-up. Conclusion: Our current experience, though preliminary, substantiates the role of hypofractionated stereotactic radiotherapy for large cavernous sinus hemangiomas. Although a longer and more extensive follow-up is needed, hypofractionated stereotactic radiotherapy of 21 Gy delivered in 3 fractions is effective in reducing the tumor volume without causing any new deficits and can be considered as a treatment modality for large cavernous sinus hemangiomas.« less

  5. Calvarial bone cavernous hemangioma with intradural invasion: An unusual aggressive course-Case report and literature review.

    PubMed

    Nasi, Davide; Somma, Lucia di; Iacoangeli, Maurizio; Liverotti, Valentina; Zizzi, Antonio; Dobran, Mauro; Gladi, Maurizio; Scerrati, Massimo

    2016-01-01

    Cavernous hemangioma of the skull is a rare pathological diagnosis, accounting for 0.2% of bone tumors and 7% of skull tumors. Usually calvarial bone cavernous hemangioma are associated with a benign clinical course and, despite their enlargement and subsequent erosion of the surrounding bone, the inner table of the skull remains intact and the lesion is completely extracranial. The authors present the unique case of a huge left frontal bone cavernous malformation with intradural extension and brain compression determining a right hemiparesis. Calvarial cavernous hemangiomas are benign tumors. They arise from vessels in the diploic space and tend to involve the outer table of the skull with relative sparing of the inner table. More extensive involvement of the inner table and extradural space is very unusual and few cases are reported in literature. To the best of our knowledge, intradural invasion of calvarial hemangioma has not been previously reported. Our case highlights the possibility of an aggressive course of this rare benign pathology. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Calvarial bone cavernous hemangioma with intradural invasion: An unusual aggressive course—Case report and literature review

    PubMed Central

    Nasi, Davide; Somma, Lucia di; Iacoangeli, Maurizio; Liverotti, Valentina; Zizzi, Antonio; Dobran, Mauro; Gladi, Maurizio; Scerrati, Massimo

    2016-01-01

    Introduction Cavernous hemangioma of the skull is a rare pathological diagnosis, accounting for 0.2% of bone tumors and 7% of skull tumors. Usually calvarial bone cavernous hemangioma are associated with a benign clinical course and, despite their enlargement and subsequent erosion of the surrounding bone, the inner table of the skull remains intact and the lesion is completely extracranial. Presentation of a case The authors present the unique case of a huge left frontal bone cavernous malformation with intradural extension and brain compression determining a right hemiparesis. Discussion Calvarial cavernous hemangiomas are benign tumors. They arise from vessels in the diploic space and tend to involve the outer table of the skull with relative sparing of the inner table. More extensive involvement of the inner table and extradural space is very unusual and few cases are reported in literature. To the best of our knowledge, intradural invasion of calvarial hemangioma has not been previously reported. Conclusion Our case highlights the possibility of an aggressive course of this rare benign pathology. PMID:27061482

  7. Designed angiopoietin-1 variant, COMP-angiopoietin-1, rescues erectile function through healthy cavernous angiogenesis in a hypercholesterolemic mouse

    PubMed Central

    Ryu, Ji-Kan; Kim, Woo Jean; Koh, Young Jun; Piao, Shuguang; Jin, Hai-Rong; Lee, Sae-Won; Choi, Min Ji; Shin, Hwa-Yean; Kwon, Mi-Hye; Jung, Keehoon; Koh, Gou Young; Suh, Jun-Kyu

    2015-01-01

    Despite the advent of oral phosphodiesterase-5 inhibitors, curative treatment for erectile dysfunction (ED) remains unavailable. Recently, the link between ED and cardiovascular disease was unveiled and the main etiology of ED was found to be vasculogenic. Therefore, neovascularization is a promising strategy for curing ED. Angiopoietin-1 (Ang1) is an angiogenic growth factor that promotes the generation of stable and functional vasculature. Here, we demonstrate that local delivery of the soluble, stable, and potent Ang1 variant, COMP-Ang1 gene or protein, into the penises of hypercholesterolemic mice increases cavernous angiogenesis, eNOS phosphorylation, and cGMP expression, resulting in full recovery of erectile function and cavernous blood flow up to 8 weeks after treatment. COMP-Ang1-induced promotion of cavernous angiogenesis and erectile function was abolished in Nos3-/- mice and in the presence of the NOS inhibitor, L-NAME. COMP-Ang1 also restored the integrity of endothelial cell-cell junction by down-regulating the expression of histone deacetylase 2 in the penis of hypercholesterolemic mice and in primary cultured mouse cavernous endothelial cells. These findings constitute a new paradigm toward curative treatment of both cavernous angiopathy and ED. PMID:25783805

  8. Flow diversion in the treatment of carotid injury and carotid-cavernous fistula after transsphenoidal surgery

    PubMed Central

    Lum, Cheemum; Ahmed, Muhammad E; Glikstein, Rafael; dos Santos, Marlise P; Lesiuk, Howard; Labib, Mohamed; Kassam, Amin B

    2015-01-01

    We describe a case of iatrogenic carotid injury with secondary carotid-cavernous fistula (CCF) treated with a silk flow diverter stent placed within the injured internal carotid artery and coils placed within the cavernous sinus. Flow diverters may offer a simple and potentially safe vessel-sparing option in this rare complication of transsphenoidal surgery. The management options are discussed and the relevant literature is reviewed. PMID:26015526

  9. Dilatancy Criteria for Salt Cavern Design: A Comparison Between Stress- and Strain-Based Approaches

    NASA Astrophysics Data System (ADS)

    Labaune, P.; Rouabhi, A.; Tijani, M.; Blanco-Martín, L.; You, T.

    2018-02-01

    This paper presents a new approach for salt cavern design, based on the use of the onset of dilatancy as a design threshold. In the proposed approach, a rheological model that includes dilatancy at the constitutive level is developed, and a strain-based dilatancy criterion is defined. As compared to classical design methods that consist in simulating cavern behavior through creep laws (fitted on long-term tests) and then using a criterion (derived from short-terms tests or experience) to determine the stability of the excavation, the proposed approach is consistent both with short- and long-term conditions. The new strain-based dilatancy criterion is compared to a stress-based dilatancy criterion through numerical simulations of salt caverns under cyclic loading conditions. The dilatancy zones predicted by the strain-based criterion are larger than the ones predicted by the stress-based criteria, which is conservative yet constructive for design purposes.

  10. Successful Transarterial Embolization of a Posttraumatic Fistula Between a Posterior Communicating Artery Aneurysm and the Cavernous Sinus: A Case Report.

    PubMed

    Jinbo, Yin; Jun, Liu; Kejie, Mou; Zheng, Zhou

    2015-01-01

    Posterior communicating artery (PCoA) aneurysm-cavernous sinus fistulae are an extremely rare complication of head injury . The treatment of PCoA aneurysm-cavernous sinus fistulae has not been well described. A 27-year-old man was admitted with a retroocular bruit and blurred vision of the left eye seven months after a severe head injury. We report the angiographic appearance of a posterior communicating artery (PCoA) aneurysm with a fistula to the cavernous sinus. This injury had been previously misinterpreted to be a PCoA aneurysm by computerized tomographic angiography (CTA). The patient was successfully treated with coils and Onyx of a fistula between the PCoA aneurysm and cavernous sinus.

  11. Coupled thermal-hydrological-mechanical behavior of rock mass surrounding a high-temperature thermal energy storage cavern at shallow depth

    DOE PAGES

    Park, Jung-Wook; Rutqvist, Jonny; Ryu, Dongwoo; ...

    2016-01-15

    The present study is aimed at numerically examining the thermal-hydrological-mechanical (THM) processes within the rock mass surrounding a cavern used for thermal energy storage (TES). We considered a cylindrical rock cavern with a height of 50 m and a radius of 10 m storing thermal energy of 350ºC as a conceptual TES model and simulated its operation for 30 years using THM coupled numerical modeling. At first, the insulator performance was not considered for the purpose of investigating the possible coupled THM behavior of the surrounding rock mass; then, the effects of an insulator were examined for different insulator thicknesses.more » The key concerns were focused on the hydro-thermal multiphase flow and heat transport in the rock mass around the thermal storage cavern, the effect of evaporation of rock mass, thermal impact on near the ground surface and the mechanical behavior of the surrounding rock mass. It is shown that the rock temperature around the cavern rapidly increased in the early stage and, consequently, evaporation of groundwater occurred, raising the fluid pressure. However, evaporation and multiphase flow did not have a significant effect on the heat transfer and mechanical behavior in spite of the high-temperature (350ºC) heat source. The simulations showed that large-scale heat flow around a cavern was expected to be conductiondominated for a reasonable value of rock mass permeability. Thermal expansion as a result of the heating of the rock mass from the storage cavern led to a ground surface uplift on the order of a few centimeters and to the development of tensile stress above the storage cavern, increasing the potentials for shear and tensile failures after a few years of the operation. Finally, the analysis showed that high tangential stress in proximity of the storage cavern can some shear failure and local damage, although large rock wall failure could likely be controlled with appropriate insulators and reinforcement.« less

  12. Severe progressive scoliosis due to huge subcutaneous cavernous hemangioma: A case report

    PubMed Central

    2011-01-01

    Cavernous hemangioma consists mainly of congenital vascular malformations present before birth and gradually increasing in size with skeletal growth. A small number of patients with cavernous hemangioma develop scoliosis, and surgical treatment for the scoliosis in such cases has not been reported to date. Here we report a 12-year-old male patient with severe progressive scoliosis due to a huge subcutaneous cavernous hemangioma, who underwent posterior correction and fusion surgery. Upon referral to our department, radiographs revealed a scoliosis of 85° at T6-L1 and a kyphosis of 58° at T4-T10. CT and MR images revealed a huge hemangioma extending from the subcutaneous region to the paraspinal muscles and the retroperitoneal space and invading the spinal canal. Posterior correction and fusion surgery using pedicle screws between T2 and L3 were performed. Massive hemorrhage from the hemangioma occurred during the surgery, with intraoperative blood loss reaching 2800 ml. The scoliosis was corrected to 59°, and the kyphosis to 45° after surgery. Seven hours after surgery, the patient suffered from hypovolemic shock and disseminated intravascular coagulation due to postoperative hemorrhage from the hemangioma. The patient developed sensory and conduction aphasia caused by cerebral hypoxia during the shock on the day of the surgery. At present, two years after the surgery, although the patient has completely recovered from the aphasia. This case illustrates that, in correction surgery for scoliosis due to huge subcutaneous cavernous hemangioma, intraoperative and postoperative intensive care for hemodynamics should be performed, since massive hemorrhage can occur during the postoperative period as well as the intraoperative period. PMID:21414205

  13. Artificial embolization of carotid-cavernous fistula with post-operative patency of internal carotid artery

    PubMed Central

    Isamat, Fabian; Salleras, V.; Miranda, A. M.

    1970-01-01

    This report deals with a patient of 86 who developed a carotid-cavernous fistula. Artificial embolization alone was considered the safest treatment for this patient and proved to be adequate. Post-operative preservation of the patency of the internal carotid artery was demonstrated by angiography. We believe this method is particularly appropriate for carotid-cavernous fistulas if it is demonstrated by angiography that the major blood flow of the carotid artery pours into the fistula. A soft-iron clip attached to the muscle can be used for external and forceful guidance of the embolus into the fistula with the help of an electromagnet, hence the patency of the internal carotid artery can be preserved. The embolus should be introduced through the external carotid artery. This is the only case known to us in which patency of the internal carotid artery was post-operatively maintained. We have reviewed 545 reported cases of surgically treated carotid-cavernous fistulas and analysed the results from simple cervical carotid ligation to the more sophisticated methods of artificial embolizations. The results obtained by artificial embolization have been consistently good, while the other techniques have failed in large percentages. Artificial embolization should be used as the primary treatment for carotid-cavernous fistula, since ligation of the internal carotid artery precludes its embolization at a later date. Images PMID:5478949

  14. [Clinical picture and complex treatment of septic thromboses of the cavernous sinuses].

    PubMed

    Mozhaev, S V; Zubkov, Iu N; Ponomarev, A M; Shimchenko, P Ia

    1980-07-01

    Under analysis are etiology, clinical picture and diagnosis of a septic thrombosis of cavernous sinuses in 28 patients. The authors have shown the interrelationship between local manifestations of the disease, injuries of the brain and its sheaths and septic complications (abscessing pneumonia as the most severe of them). A scheme of the complex treatment of patients with thrombosis of the cavernous sinus is proposed. The leading role in this treatment is played by intracarotid infusion of antibiotics in combination with anticoagulant drugs, vasodilatatory agents and novocaine as well as the therapy of septic complications (abscesses of the face and hairy part of the head, meningoencephalitis, pneumonia).

  15. Simulation of Cavern Formation and Karst Development Using Salt

    ERIC Educational Resources Information Center

    Kent, Douglas C.; Ross, Alex R.

    1975-01-01

    A salt model was developed as a teaching tool to demonstrate the development of caverns and karst topography. Salt slabs are placed in a watertight box to represent fractured limestone. Erosion resulting from water flow can be photographed in time-lapse sequence or demonstrated in the laboratory. (Author/CP)

  16. Segmentation of optical coherence tomography images for differentiation of the cavernous nerves from the prostate gland

    NASA Astrophysics Data System (ADS)

    Chitchian, Shahab; Weldon, Thomas P.; Fried, Nathaniel M.

    2009-07-01

    The cavernous nerves course along the surface of the prostate and are responsible for erectile function. Improvements in identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery may improve nerve preservation and postoperative sexual potency. Two-dimensional (2-D) optical coherence tomography (OCT) images of the rat prostate were segmented to differentiate the cavernous nerves from the prostate gland. To detect these nerves, three image features were employed: Gabor filter, Daubechies wavelet, and Laws filter. The Gabor feature was applied with different standard deviations in the x and y directions. In the Daubechies wavelet feature, an 8-tap Daubechies orthonormal wavelet was implemented, and the low-pass sub-band was chosen as the filtered image. Last, Laws feature extraction was applied to the images. The features were segmented using a nearest-neighbor classifier. N-ary morphological postprocessing was used to remove small voids. The cavernous nerves were differentiated from the prostate gland with a segmentation error rate of only 0.058+/-0.019. This algorithm may be useful for implementation in clinical endoscopic OCT systems currently being studied for potential intraoperative diagnostic use in laparoscopic and robotic nerve-sparing prostate cancer surgery.

  17. Segmentation of optical coherence tomography images for differentiation of the cavernous nerves from the prostate gland.

    PubMed

    Chitchian, Shahab; Weldon, Thomas P; Fried, Nathaniel M

    2009-01-01

    The cavernous nerves course along the surface of the prostate and are responsible for erectile function. Improvements in identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery may improve nerve preservation and postoperative sexual potency. Two-dimensional (2-D) optical coherence tomography (OCT) images of the rat prostate were segmented to differentiate the cavernous nerves from the prostate gland. To detect these nerves, three image features were employed: Gabor filter, Daubechies wavelet, and Laws filter. The Gabor feature was applied with different standard deviations in the x and y directions. In the Daubechies wavelet feature, an 8-tap Daubechies orthonormal wavelet was implemented, and the low-pass sub-band was chosen as the filtered image. Last, Laws feature extraction was applied to the images. The features were segmented using a nearest-neighbor classifier. N-ary morphological postprocessing was used to remove small voids. The cavernous nerves were differentiated from the prostate gland with a segmentation error rate of only 0.058+/-0.019. This algorithm may be useful for implementation in clinical endoscopic OCT systems currently being studied for potential intraoperative diagnostic use in laparoscopic and robotic nerve-sparing prostate cancer surgery.

  18. Urethral cavernous hemangioma in a female patient: a rare entity

    PubMed Central

    Bolat, Mustafa Suat; Yüzüncü, Kubilay; Akdeniz, Ekrem; Demirdoven, Ayse Nurten

    2015-01-01

    Genitourinary hemangiomas are rare entities of the urinary system. We reported a female patient who suffered dyspareunia and intermitant hematuria that was proved as urethral cavernous hemangioma. Despite its benign nature, hemangiomas may recur due to incomplet excision. PMID:26985270

  19. Benign mass in tonsil- cavernous hemangioma.

    PubMed

    Joseph, Sumitha; Prakash, M; Mohammed, Hafida K; Govar, Aberna

    2013-10-01

    Cavernous hemangioma is also called as 'ANGIOMA CAVERNOSUM' or 'CAVERNOMA' as benign lesion of blood vessels. They are similar to strawberry hemangioma but deeply situated. Although most often associated with skin it is also sometimes found in mucous membrane, brain and the viscera. The diagnosis of hemangiomas is mainly based on clinical evaluation . Isolated hemangiomas in the tonsillar tissue is a rare occurance. In this we report had a case of adult tonsillar hemangioma of left side associated with recurrent tonsillitis . He was effectively managed surgically without any complications.

  20. Navigated transcranial magnetic stimulation in preoperative planning for the treatment of motor area cavernous angiomas

    PubMed Central

    Paiva, Wellingson Silva; Fonoff, Erich Talamoni; Marcolin, Marco Antonio; Bor-Seng-Shu, Edson; Figueiredo, Eberval Gadelha; Teixeira, Manoel Jacobsen

    2013-01-01

    Since the introduction of microscopic techniques, radical surgery for cavernous angiomas has become a recommended treatment option. However, the treatment of motor area cavernous angioma represents a great challenge for the surgical team. Here, we describe an approach guided by frameless neuronavigation and preoperative functional mapping with transcranial magnetic stimulation (TMS), for surgical planning. We used TMS to map the motor cortex and its relationship with the angioma. We achieved complete resection of the lesions in the surgeries, while avoiding areas of motor response identified during the preoperative mapping. We verified the complete control of seizures (Engel class 1A) in the patients with previous refractory epilepsy. Postsurgery, one patient was seizure-free without medication, and two patients required only one medication for seizure control. Thus, navigated TMS appears to be a useful tool, in preoperative planning for cavernous angiomas of the motor area. PMID:24353424

  1. Virtual Reality Model of the Three-Dimensional Anatomy of the Cavernous Sinus Based on a Cadaveric Image and Dissection.

    PubMed

    Qian, Zeng-Hui; Feng, Xu; Li, Yang; Tang, Ke

    2018-01-01

    Studying the three-dimensional (3D) anatomy of the cavernous sinus is essential for treating lesions in this region with skull base surgeries. Cadaver dissection is a conventional method that has insurmountable flaws with regard to understanding spatial anatomy. The authors' research aimed to build an image model of the cavernous sinus region in a virtual reality system to precisely, individually and objectively elucidate the complete and local stereo-anatomy. Computed tomography and magnetic resonance imaging scans were performed on 5 adult cadaver heads. Latex mixed with contrast agent was injected into the arterial system and then into the venous system. Computed tomography scans were performed again following the 2 injections. Magnetic resonance imaging scans were performed again after the cranial nerves were exposed. Image data were input into a virtual reality system to establish a model of the cavernous sinus. Observation results of the image models were compared with those of the cadaver heads. Visualization of the cavernous sinus region models built using the virtual reality system was good for all the cadavers. High resolutions were achieved for the images of different tissues. The observed results were consistent with those of the cadaver head. The spatial architecture and modality of the cavernous sinus were clearly displayed in the 3D model by rotating the model and conveniently changing its transparency. A 3D virtual reality model of the cavernous sinus region is helpful for globally and objectively understanding anatomy. The observation procedure was accurate, convenient, noninvasive, and time and specimen saving.

  2. Injectable self inflating hydrogel pellet expanders for the treatment of orbital volume deficiency in congenital microphthalmos: preliminary results with a new therapeutic approach

    PubMed Central

    Schittkowski, M P; Guthoff, R F

    2006-01-01

    Background/aim Children with congenital microphthalmos are usually able to wear an eye prosthesis but the cosmetic aspect is determined by the size of the orbital volume deficiency. Instead of using a ball shaped standard hydrogel expander or a regular orbital implant, which would necessitate enucleation of the microphthalmic eye, this study investigates the feasibility of volume augmentation with injectable pellet expanders, as formerly suggested for acquired anophthalmos in adults only. Method The pellet expander is made from a self inflating hydrogel that takes up water by osmosis (dry state: length 8 mm, diameter 2 mm, volume 0.025 ml; in vitro hydrated state after around 1 day: length 15 mm, diameter 4 mm, volume 0.24 ml; swelling capacity: 9.6‐fold). This report concerns six patients (two girls and four boys) aged between 4 months and 42 months with unilateral microphthalmos who were treated by injection of 4–14 pellet expanders into the retrobulbar orbital tissue. Volume augmentation was 1–3.5 ml. The pellets were injected using a customised trocar and placed behind the microphthalmos directed into the intraconal space. Results The increasing orbital volume was noticeable within 2 days and was confirmed by ultrasonography and magnetic resonance imaging. The final result can be anticipated by the volume augmentation effect produced by the amount of saline solution injected in the orbital apex region. All patients were fitted with an artificial eye, which was subsequently enlarged every 3–5 months. Anophthalmic enophthalmos was fully compensated with this technique. No complications have been encountered to date. Conclusions Orbital volume augmentation with injectable self inflating hydrogel expander pellets is apparently a safe, quick, and minimally invasive technique for various indications in orbital reconstructive surgery—for example, to treat an enophthalmic appearance in microphthalmos and congenital or acquired

  3. Building the 3D Geological Model of Wall Rock of Salt Caverns Based on Integration Method of Multi-source data

    NASA Astrophysics Data System (ADS)

    Yongzhi, WANG; hui, WANG; Lixia, LIAO; Dongsen, LI

    2017-02-01

    In order to analyse the geological characteristics of salt rock and stability of salt caverns, rough three-dimensional (3D) models of salt rock stratum and the 3D models of salt caverns on study areas are built by 3D GIS spatial modeling technique. During implementing, multi-source data, such as basic geographic data, DEM, geological plane map, geological section map, engineering geological data, and sonar data are used. In this study, the 3D spatial analyzing and calculation methods, such as 3D GIS intersection detection method in three-dimensional space, Boolean operations between three-dimensional space entities, three-dimensional space grid discretization, are used to build 3D models on wall rock of salt caverns. Our methods can provide effective calculation models for numerical simulation and analysis of the creep characteristics of wall rock in salt caverns.

  4. Focal dystonia secondary to cavernous angioma of the basal ganglia: case report and review of the literature.

    PubMed

    Lorenzana, L; Cabezudo, J M; Porras, L F; Polaina, M; Rodriguez-Sanchez, J A; Garcia-Yagüe, L M

    1992-12-01

    The case of a young woman with focal dystonia of the hand due to a cavernous angioma of the basal ganglia is presented. The lesion involved the anterior third of the lentiform nucleus and a large portion of white matter anterior to this nucleus and lateral to the head of the caudate, as shown by magnetic resonance imaging; it was completely removed through a computed tomography-assisted stereotactic craniotomy by microsurgical technique, resulting in the cure of the patient. These facts support the pathophysiological hypothesis of a disruption of the striatopallidothalamic projection to the premotor cortex as the cause of symptomatic dystonia. A review of the reported cases of cavernous angiomas of the deep cerebral gray nuclei shows that this is the first case of cavernous angioma associated with movement disorder.

  5. Evaluation of Computational Method of High Reynolds Number Slurry Flow for Caverns Backfilling

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

    Bettin, Giorgia

    2015-05-01

    The abandonment of salt caverns used for brining or product storage poses a significant environmental and economic risk. Risk mitigation can in part be address ed by the process of backfilling which can improve the cavern geomechanical stability and reduce the risk o f fluid loss to the environment. This study evaluate s a currently available computational tool , Barracuda, to simulate such process es as slurry flow at high Reynolds number with high particle loading . Using Barracuda software, a parametric sequence of simu lations evaluated slurry flow at Re ynolds number up to 15000 and loading up tomore » 25%. Li mitations come into the long time required to run these simulation s due in particular to the mesh size requirement at the jet nozzle. This study has found that slurry - jet width and centerline velocities are functions of Re ynold s number and volume fractio n The solid phase was found to spread less than the water - phase with a spreading rate smaller than 1 , dependent on the volume fraction. Particle size distribution does seem to have a large influence on the jet flow development. This study constitutes a first step to understand the behavior of highly loaded slurries and their ultimate application to cavern backfilling.« less

  6. Continuous-wave vs. pulsed infrared laser stimulation of the rat prostate cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Cilip, Christopher M.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2011-03-01

    Optical nerve stimulation has recently been developed as an alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuouswave (CW) infrared laser radiation, for potential diagnostic applications. A Thulium fiber laser (λ = 1870 nm) was used for non-contact optical stimulation of the rat prostate cavernous nerves, in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, was achieved with the laser operating in either CW mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation was observed to be primarily dependent on a threshold nerve temperature (42-45 °C), not an incident fluence, as previously reported. CW optical nerve stimulation provides a significantly faster ICP response time using a laser with lower power output than pulsed stimulation. CW optical nerve stimulation may therefore represent an alternative mode of stimulation for intra-operative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

  7. Analysis of the evolution of the instability process of a coastal cavern

    NASA Astrophysics Data System (ADS)

    Lollino, P.; Reina, A.

    2012-04-01

    This work concerns the study performed for the interpretation of the potential failure mechanism of a large natural cavern, which is located along the rocky cliffs of Polignano a Mare town (Apulia, Southern Italy) under an intensely urbanised area. This cavern, which is located at the sea level, was formed due to an intense process of salt and wave erosion, mainly acting during sea storms, within a rock mass formed of a lower stratified limestone mass and an upper soft calcarenite mass. Therefore, the influence of the climatic factors and of the upward erosion process within the cavern has been specifically investigated. At present, the thickness of the cave roof, which has a dome shape, is less than 10 metres in the centre and several buildings are founded on the ground surface above. In 2006 a large calcarenite block, of about 1.5 m diameter, fell down from the roof of the cavern and afterwards field and laboratory investigations as well as both simple analytical methods and elasto-plastic numerical modelling were carried out in order to assess the current state of the roof and to interpret the effects of the potential evolution of the inner erosion and of the local failure processes of the cave. As such, a detailed geo-structural survey has firstly been carried out, together with laboratory and in-situ testing for the geomechanical characterisation of the rock materials and of the corresponding joints. An analysis of the sea storms occurred within the observation period has also been performed by considering daily rainfall and wind data. The rate of erosion has been measured by means of special nets installed at the sea level to collect the material falling down from the roof and the corresponding measurements, which lasted for about one year, indicate an erosion rate of at least 0.005 m3/month. A structural monitoring system, including extensometers and joint-meters, was also installed in several points of the cave in order to measure eventual block

  8. Characterizing Excavation Damaged Zone and Stability of Pressurized Lined Rock Caverns for Underground Compressed Air Energy Storage

    NASA Astrophysics Data System (ADS)

    Kim, Hyung-Mok; Rutqvist, Jonny; Jeong, Ju-Hwan; Choi, Byung-Hee; Ryu, Dong-Woo; Song, Won-Kyong

    2013-09-01

    In this paper, we investigate the influence of the excavation damaged zone (EDZ) on the geomechanical performance of compressed air energy storage (CAES) in lined rock caverns. We conducted a detailed characterization of the EDZ in rock caverns that have been excavated for a Korean pilot test program on CAES in (concrete) lined rock caverns at shallow depth. The EDZ was characterized by measurements of P- and S-wave velocities and permeability across the EDZ and into undisturbed host rock. Moreover, we constructed an in situ concrete lining model and conducted permeability measurements in boreholes penetrating the concrete, through the EDZ and into the undisturbed host rock. Using the site-specific conditions and the results of the EDZ characterization, we carried out a model simulation to investigate the influence of the EDZ on the CAES performance, in particular related to geomechanical responses and stability. We used a modeling approach including coupled thermodynamic multiphase flow and geomechanics, which was proven to be useful in previous generic CAES studies. Our modeling results showed that the potential for inducing tensile fractures and air leakage through the concrete lining could be substantially reduced if the EDZ around the cavern could be minimized. Moreover, the results showed that the most favorable design for reducing the potential for tensile failure in the lining would be a relatively compliant concrete lining with a tight inner seal, and a relatively stiff (uncompliant) host rock with a minimized EDZ. Because EDZ compliance depends on its compressibility (or modulus) and thickness, care should be taken during drill and blast operations to minimize the damage to the cavern walls.

  9. The Medial Extra-Sellar Corridor to the Cavernous Sinus: Anatomic Description and Clinical Correlation.

    PubMed

    Theodosopoulos, Philip V; Cebula, Helene; Kurbanov, Almaz; Cabero, Arnau Benet; Osorio, Joseph A; Zimmer, Lee A; Froelich, Sebastien C; Keller, Jeffrey T

    2016-12-01

    The zenith of surgical interest in the cavernous sinus peaked in the 1980s, as evidenced by reports of 10 surgical triangles that could access the contents of the lateral sellar compartment (LSC). However, these transcranial approaches later became marginalized, first by radiosurgery's popularity and lower morbidity, and then by clinical potential of endoscopic corridors noted in several qualitative studies. Our anatomic study, taking a contemporary look at the medial extra-sellar corridor, gives a detailed qualitative-quantitative analysis for its use with increasingly popular endoscopic endonasal approaches to the cavernous sinus. In 20 cadaveric specimens, we re-examined the anatomic landmarks of the medial corridor into the LSC with qualitative descriptions and measurements. An illustrative case highlights a recurrent symptomatic pituitary adenoma that invaded the cavernous sinus approached through the medial corridor. The corridor's shape varied from tetrahedron to hexahedron. Comparing right and left sides, width averaged 3.6 ± 4.5 mm and 4.0 ± 4.4 mm, and height averaged 2.3 mm and 2.1 mm, respectively. About 35% of sides showed ample space for access into the cavernous sinus. Our case report of successful outcome lends support for the safety and efficacy of this endoscopic approach. Our re-examination of this particular surgical access into the LSC refines the understanding of the medial extra-sellar corridor as a main endoscopic access route to this compartment. Achieving safe access to the contents of the LSC, this 11th triangle is clinically relevant and potentially superior for select lesions in this region. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Myometrial cavernous hemangioma with pulmonary thromboembolism in a post-partum woman: a case report and review of the literature.

    PubMed

    Bhavsar, Tapan; Wurzel, John; Duker, Nahum

    2012-11-23

    Cavernous hemangiomas of the uterus are rare benign vascular lesions. Nine cases of diffuse cavernous hemangioma of the gravid uterus have been reported, most of which diffusely involved the myometrium. These vascular malformations are clinically significant, and may cause pronounced bleeding resulting in maternal or fetal demise. Thrombosis of cavernous hemangiomas of the uterus has been previously reported. We here report the first case in which a thrombosed cavernous hemangioma of the myometrium resulted in a fatal pulmonary embolism in a post-partum woman. A 25-year-old obese African-American woman who had one pregnancy and was delivered of twins by cesarean section was admitted 1 week after the successful delivery. The 12-day clinical course included ventilator-dependent respiratory failure, systemic hypertension, methicillin-resistant Staphylococcus aureus in the sputum, leukocytosis and asystole. A transabdominal ultrasound examination showed heterogeneous thickened and irregular products in the endometrial canal. The laboratory values were relevant for an increased prothrombin time, activated partial thromboplastin time, ferritin and a decrease in hemoglobin. The clinical cause of death was cited as acute respiratory distress syndrome. At autopsy, a 400g spongy, hemorrhagic uterus with multiple cystic spaces measuring approximately 0.5 × 0.4cm filled with thrombi within the myometrium was identified. Immunohistological examination with a CD31 stain for vascular endothelium associated antigen confirmed several endothelium-lined vessels, some of which contained thrombi. These histological features were consistent with cavernous hemangioma of the myometrium. A histological examination of the lungs revealed multiple fresh thromboemboli in small- and medium-sized pulmonary arteries in the right upper and lower lobes without organization, but with adjacent areas of fresh hemorrhagic infarction. This case underscores the importance of a high index of suspicion in

  11. Phenotypic modulation of corpus cavernosum smooth muscle cells in a rat model of cavernous neurectomy.

    PubMed

    Yang, Fan; Zhao, Jian F; Shou, Qi Y; Huang, Xiao J; Chen, Gang; Yang, Ke B; Zhang, Shi G; Lv, Bo D; Fu, Hui Y

    2014-01-01

    Patients undergoing radical prostatectomy (RP) are at high risk for erectile dysfunction (ED) due to potential cavernous nerve (CN) damage during surgery. Penile hypoxia after RP is thought to significantly contribute to ED pathogenesis. We previously showed that corpora cavernosum smooth muscle cells (CCSMCs) undergo phenotypic modulation under hypoxic conditions in vitro. Here, we studied such changes in an in vivo post-RP ED model by investigating CCSMCs in bilateral cavernous neurectomy (BCN) rats. Sprague-Dawley rats underwent sham (n = 12) or BCN (n = 12) surgery. After 12 weeks, they were injected with apomorphine to determine erectile function. The penile tissues were harvested and assessed for fibrosis using Masson trichrome staining and for molecular markers of phenotypic modulation using immunohistochemistry and western blotting. CCSMC morphological structure was evaluated by hematoxylin-eosin (H&E) staining and transmission electron microscopy (TEM). Erectile function was significantly lower in BCN rats than in sham rats. BCN increased hypoxia-inducible factor-1α and collagen protein expression in corpora cavernous tissue. H&E staining and TEM showed that CCSMCs in BCN rats underwent hypertrophy and showed rough endoplasmic reticulum formation. The expression of CCSMC phenotypic markers, such as smooth muscle α-actin, smooth muscle myosin heavy chain, and desmin, was markedly lower, whereas vimentin protein expression was significantly higher in BCN rats than in control rats. CCSMCs undergo phenotype modulation in rats with cavernous neurectomy. The results have unveiled physiological transformations that occur at the cellular and molecular levels and have helped characterize CN injury-induced ED.

  12. Cavernous hemangioma of the rib: a rare diagnosis.

    PubMed

    Gourgiotis, Stavros; Piyis, Anastasios; Panagiotopoulos, Nikolaos; Panayotopoulos, Panayotis; Salemis, Nikolaos S

    2010-01-01

    Hemangioma of the rib is an uncommon benign vascular tumour. A case of rib hemangioma in a 29-year-old woman is presented. Chest roentgenogram and computed tomography revealed a mass along the inner surface of the 7th left rib with bone destruction. She underwent resection of the 7th rib. The pathologic diagnosis was cavernous hemangioma. Hemangiomas of the rib are rare tumours but should be kept in mind in the differential diagnosis of rib tumours.

  13. Study on Excavation of Particular Part of Underground Cavern for Hydropower Station

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Zhang, Feng; Shang, Qin; Zheng, Huakang

    2018-01-01

    In the present study, regarding four particular parts of underground cavern for hydropower station, i.e., crown, high sidewall, the intersection between high sidewall and tunnel and tailrace tunnel, by summarizing the previous construction experience, we have proposed the excavation approach based on “middle first and edge later, soft first and hard later”, “layered construction by excavating the thin layer first and supporting as the layer advances”, “tunnel first and wall later, small tunnels into large ones” and “excavating tunnels supported by separation piers”. In addition, the proposed excavation approach has been analyzed and verified with finite element numerical simulation. The result has indicated that the proposed special approach is reasonable and effective to reduce the turbulence on surrounding rocks, lower the influence of unloading during excavating and enhance the local and global stability of caverns and surrounding rocks.

  14. Cavernous sinus involvement is not a risk factor for the primary tumor site treatment outcome of Sinonasal adenoid cystic carcinoma.

    PubMed

    Lee, Yi-Chan; Lee, Ta-Jen; Tsang, Ngan-Ming; Huang, Yenlin; Hsu, Cheng-Lung; Hsin, Li-Jen; Lee, Yi-Hsuan; Chang, Kai-Ping

    2018-02-05

    Sinonasal adenoid cystic carcinoma is a rare malignancy of the head and neck. Cavernous sinus invasion from sinonasal adenoid cystic carcinoma and its related management have rarely been investigated. This study evaluated the relationship between treatment outcome and cavernous sinus involvement in addition to other parameters. A retrospective case series study was conducted at a tertiary referral center. The medical records of 47 patients diagnosed with primary sinonasal adenoid cystic carcinoma between 1984 and 2015 were retrospectively reviewed. The survival impact of the primary treatment modalities and the anatomic sites of tumor involvement were analyzed. Cavernous sinus invasion was observed in 8 patients (17%), of whom 7 had ACC tumors originating from the maxillary sinus. The results of univariate analysis revealed that tumor stage, primary surgery, and the absence of skull-base and infratemporal fossa invasion were associated with better overall survival (P = 0.033, P = 0.012, P = 0.011, and P = 0.040, respectively) and better disease-free survival (P = 0.019, P = 0.001, P = 0.017, and P = 0.029, respectively). Multivariate analysis identified primary surgery as the only independent prognostic factor for disease-free survival (P = 0.026). Cavernous sinus invasion by sinonasal adenoid cystic carcinoma was not associated with worse overall survival or disease-free survival (P = 0.200 and P = 0.198, respectively). Because maxillary adenoid cystic carcinoma is associated with a higher rate of cavernous sinus invasion, such cases warrant caution during preoperative planning. Primary surgery as the initial therapy provides better locoregional control and survival for patients with sinonasal adenoid cystic carcinoma. Cavernous sinus invasion did not significantly impact survival; thus, it should not be regarded as a contraindication for curative treatment.

  15. Brain stem venous congestion due to dural arteriovenous fistulas of the cavernous sinus.

    PubMed

    Kai, Y; Hamada, J I; Morioka, M; Yano, S; Ushio, Y

    2004-10-01

    Venous congestion of the brain stem due to dural arteriovenous fistulas (DAVFs) in the cavernous sinus is rare and presents therapeutic challenges. To assess the prognosis of patients with symptomatic DAVFs and brain stem dysfunction, we evaluated the degree of venous ischemia by examining pre- and post-treatment magnetic resonance images (MRI) in 2 patients presenting with venous congestion of the brain stem. A 56-year-old woman with left hemiparesis and a 70-year-old woman with gait disturbance attributable to right cavernous sinus DAVFs were referred to our hospital. In both cases, T2-weighted magnetic resonance imaging (MRI) disclosed a hyperintensity lesion in the brainstem due to venous congestion. Both patients underwent open surgery for direct embolization of the cavernous sinus because there were no approach routes for transvenous embolization. The patient whose pretreatment MRI demonstrated Gd enhancement continued to manifest neurological deficits and persistence of the abnormal hyperintensity on post-treatment T2-weighted MRI. In the other patient whose pretreatment MRI showed no Gd enhancement, treatment produced a complete response of her neurological deficit and disappearance of the abnormal hyperintensity area. We tentatively conclude that lesions corresponding to hyperintensity areas on non-Gd-enhanced, T2-weighted MRI may reflect a reversible condition whereas lesions identified as hyperintense areas on GD-enhanced T2-weighted MRI may be indicative of irreversibility.

  16. Cavernous Hemangioma of the Rib: A Rare Diagnosis

    PubMed Central

    Gourgiotis, Stavros; Piyis, Anastasios; Panagiotopoulos, Nikolaos; Panayotopoulos, Panayotis; Salemis, Nikolaos S.

    2010-01-01

    Hemangioma of the rib is an uncommon benign vascular tumour. A case of rib hemangioma in a 29-year-old woman is presented. Chest roentgenogram and computed tomography revealed a mass along the inner surface of the 7th left rib with bone destruction. She underwent resection of the 7th rib. The pathologic diagnosis was cavernous hemangioma. Hemangiomas of the rib are rare tumours but should be kept in mind in the differential diagnosis of rib tumours. PMID:20585365

  17. Hypertrophic olivary degeneration following surgical resection or gamma knife radiosurgery of brainstem cavernous malformations: an 11-case series and a review of literature.

    PubMed

    Yun, Jung-Ho; Ahn, Jae Sung; Park, Jung Cheol; Kwon, Do Hoon; Kwun, Byung Duk; Kim, Chang Jin

    2013-03-01

    We describe 11 patients with hypertrophic olivary degeneration (HOD) after surgical resection or gamma knife radiosurgery for brainstem cavernous malformations. In addition, we statistically analyzed the predicting factors associated with the development of HOD. From January 2001 to May 2011, a total of 73 patients (30 in the surgical group and 43 in the radiosurgery group) with brainstem cavernous malformations were treated in our institute. Of them, 11 patients (incidence: 15 %) developed HOD with high signal intensity on T2-weighted MRI during follow-up. The predicting factors (location, size, age, and treatment method) associated with the development of HOD were statistically analyzed. Among the 11 HOD patients, seven patients received surgical resection and four patients received gamma knife radiosurgery. Six patients had bilateral HOD and the remaining five patients had unilateral HOD. Overall HOD-associated symptoms presented in four patients, including three palatal tremors and one ataxia. In all four patients with symptoms, these symptoms disappeared incompletely within the clinical follow-up period. The size of the cavernous malformation, age of patient, and treatment methods were not significantly correlated with the development of HOD. A significantly higher incidence of HOD was associated with midbrain cavernous malformations than with pontine or medulla cavernous malformations. HOD should be recognized as a non-infrequent complication of surgical resection or gamma knife radiosurgery within the brainstem, especially for midbrain cavernous malformations. In addition, to the best of our knowledge, this is the first report on HOD development after radiosurgery.

  18. Isolated nonpulsatile enophthalmos in neurofibromatosis: An uncommon entity

    PubMed Central

    Singh, Swati; Mulay, Kaustubh; Mittal, Vikas

    2017-01-01

    Isolated enophthalmos is a rarely observed entity in neurofibromatosis (NF). A 12-year-old male presented with right lower eyelid fat prolapse and enophthalmos for the past 7 years. There was no history of antecedent trauma/surgery. Computed tomography of orbit revealed an ill-defined intraconal hyperdense lesion located between lateral and inferior rectus along with an enlarged inferior orbital fissure (IOF). Superior orbital fissure was minimally widened without prolapse of any intracranial contents. Excision biopsy along with repair of widened IOF was performed through inferior transconjunctival route. Histopathology was suggestive of plexiform neurofibroma with positivity for S-100 and epithelial membrane antigen. No associated cutaneous lesions were present. Nonpulsatile enophthalmos with eyelid fat prolapse can be a presenting sign of NF. PMID:29044092

  19. Isolated nonpulsatile enophthalmos in neurofibromatosis: An uncommon entity.

    PubMed

    Singh, Swati; Mulay, Kaustubh; Mittal, Vikas

    2017-10-01

    Isolated enophthalmos is a rarely observed entity in neurofibromatosis (NF). A 12-year-old male presented with right lower eyelid fat prolapse and enophthalmos for the past 7 years. There was no history of antecedent trauma/surgery. Computed tomography of orbit revealed an ill-defined intraconal hyperdense lesion located between lateral and inferior rectus along with an enlarged inferior orbital fissure (IOF). Superior orbital fissure was minimally widened without prolapse of any intracranial contents. Excision biopsy along with repair of widened IOF was performed through inferior transconjunctival route. Histopathology was suggestive of plexiform neurofibroma with positivity for S-100 and epithelial membrane antigen. No associated cutaneous lesions were present. Nonpulsatile enophthalmos with eyelid fat prolapse can be a presenting sign of NF.

  20. Long-Term Endovascular Treatment Outcome of 46 Patients with Cavernous Sinus Dural Arteriovenous Fistulas Presenting with Ophthalmic Symptoms

    PubMed Central

    Pashapour, Ali; Mohammadian, Reza; Salehpour, Firooz; Sharifipour, Ehsan; Mansourizade, Reza; Mahdavifard, Ali; Salehi, Mohamadgharib; Mirzaii, Farhad; Sariaslani, Payam; Fatahzade Ardalani, Ghasem; Altafi, Davar

    2014-01-01

    Summary Ocular symptoms are regularly observed in patients with cavernous sinus dural arteriovenous fistulas (cDAVF). We aimed to evaluate the long-term efficacy and safety of endovascular approaches in patients with cDAVF presenting with different ocular symptoms. In a prospective study between June 2008 and March 2013, 46 patients with ocular symptoms due to cDAVF who were not eligible for conservative therapy, met the inclusion criteria and underwent endovascular treatment. They underwent a transarterial approach with histoacryl glue injections or transvenous coil embolization, all in one session. They were followed up for a mean period of 17.3 months (range 7 to 30 months) clinically and using angiography. The mean age of patients was 36.8 years (18-60) and 65% of them were male. All patients showed venous drainage into the superior and inferior orbital veins. Access to the cavernous sinus was transvenous in ten patients, transarterial in 26 patients, and mixed in ten patients. Initial symptoms were improved in 97.8% of patients and did not recur during the study follow-up. The procedural complications included: blurred vision, transient sixth nerve palsy and exacerbation of chemoproptosis in two, one and two patients respectively that completely resolved in initial weeks with no recurrence. No patient worsened or developed new symptoms suggestive of a recurrent fistula during the follow-up period. One patient experienced intracranial dissection of the internal carotid artery and ischemic stroke with an unfinished procedure. The relief of early presentation was durable in long-term follow-up and the cured lesions were stable in angiographic controls. Favorable and durable outcomes could be obtained following endovascular approaches for cDAVF presenting with different ocular symptoms. PMID:25196621

  1. Losartan, an Angiotensin type I receptor, restores erectile function by downregulation of cavernous renin-angiotensin system in streptozocin-induced diabetic rats.

    PubMed

    Yang, Rong; Yang, Bin; Wen, Yanting; Fang, Feng; Cui, Souxi; Lin, Guiting; Sun, Zeyu; Wang, Run; Dai, Yutian

    2009-03-01

    The high incidence of erectile dysfunction (ED) in diabetes highlights the need for good treatment strategies. Recent evidence indicates that blockade of the angiotensin type I receptor (AT1) may reverse ED from various diseases. To explore the role of cavernous renin-angiotensin system (RAS) in the pathogenesis of diabetic ED and the role of losartan in the treatment of diabetic ED. The AT1 blocker (ARB) losartan (30 mg/kg/d) was administered to rats with streptozocin (65 mg/kg)-induced diabetes. Erectile function, cavernous structure, and tissue gene and protein expression of RAS in the corpora cavernosa were studied. We sought to determine the changes of cavernous RAS in the condition of diabetes and after treatment with losartan. RAS components (angiotensinogen, [pro]renin receptor, angiotensin-converting enzyme [ACE], and AT1) were expressed in cavernosal tissue. In diabetic rats, RAS components were upregulated, resulting in the increased concentration of angiotensin II (Ang II) in the corpora. A positive feedback loop for Ang II formation in cavernosum was also identified, which could contribute to overactivity of cavernous RAS in diabetic rats. Administration of losartan blocked the effect of Ang II, downregulated the expression of AT1 and Ang II generated locally, and partially restored erectile function (losartan-treated group revealed an improved intracavernous pressure/mean systemic arterial pressure ratio as compared with the diabetic group (0.480 +/- 0.031 vs. 0.329 +/- 0.020, P < 0.01). However, losartan could not elevate the reduced smooth muscle/collagen ratio in diabetic rats. The cavernous RAS plays a role in modulating erectile function in corpora cavernosa and is involved in the pathogenesis of diabetic ED. ARB can restore diabetic ED through downregulating cavernous RAS.

  2. Orbital cellulitis: clinical course and management challenges. the Lagos State University Teaching Hospital experience.

    PubMed

    Balogun, Bolanle G; Balogun, Modupe M; Adekoya, Bola J

    2012-01-01

    Orbital cellulitis is a devastating acute infection of orbital soft tissues located posterior to the orbital septum. It is both vision and life-threatening. It is an ocular emergency which most often present in childhood. This article reviewed cases presenting during the study period with the view of examining the pattern of presentation, clinical course and management challenges. A retrospective study was conducted on patients presenting with orbital cellulitis between January 2008 and June 2011. Socio-demographic data, entry and discharge visual acuity, presenting complaints, predisposing factors, duration of complaints, admission period and complications were extracted from clinical records and analyzed. Seventeen (17) patients presented with orbital cellulitis constituting 6.2% of ocular emergency admissions during the study period. Twelve (70.6%) were males. Thirteen (76.5%) were children. The major predisposing factors were upper respiratory tract infections, and facial and globe injuries in five (22.7%) cases respectively. Only five (29.4%), presented within three days of disease onset. Average duration of admission was 10.6 days. Complications during the course of disease were category 4 and 5 blindness in five (23.5%), orbital abscess four (23.5%), cavernous sinus thrombosis two (11.8%), contralateral preseptal cellulitis two (11.8%) and exposure keratopathy in one (5.9%). Orbital cellulitis has remained a disease with high ocular morbidity. The major management challenges were poor financial status of patients precluding necessary diagnostic laboratory and imaging studies. Early recognition, diagnosis and treatment are crucial to the preservation of vision and reduced occurrence of complications. The importance of record keeping is also highlighted.

  3. Congenital intraosseous cavernous hemangioma of the skull: an unusual case.

    PubMed

    Rumana, Makhdoomi; Khursheed, Nayil; Farhat, Mustafa; Othman, Salim; Masood, Laharwal

    2013-01-01

    Intraosseous hemangiomas are benign vascular malformations mostly seen in the spine. They rarely occur in the skull. The usual age-group involved is the 2nd to 4th decades, and females outnumber males. We hereby report a rare case of congenital intraosseous cavernous hemangioma of the skull bone in a male infant. The patient underwent total excision of the lesion. © 2014 S. Karger AG, Basel.

  4. [Pontine cavernous angioma (cavernoma) with initial ENT manifestations].

    PubMed

    Pino Rivero, V; González Palomino, A; Pantoja Hernández, C G; Trinidad Ruíz, G; Marqués Rebollo, L; Blasco Huelva, A

    2006-01-01

    We report the case of a 22 years old female who consulted us for facial parestesias, hearing loss in right ear and sudden tinnitus. Her audiometry showed an unilateral discreet sensorineural hipoacusia and the cranial IRM, a mass of 20 mm diameter in right pontine region and bulbus informed as cavernous angioma with signs of recent bleeding. The patient was sent to Neurosurgery but she refused the intervention. The risk of hemorrhage in the cavernomas is estimated at 0.25% to 1.6% per year and represents the main reason to advise a surgical treatment.

  5. Gamma Knife radiosurgery for hemangioma of the cavernous sinus.

    PubMed

    Lee, Cheng-Chia; Sheehan, Jason P; Kano, Hideyuki; Akpinar, Berkcan; Martinez-Alvarez, Roberto; Martinez-Moreno, Nuria; Guo, Wan-Yuo; Lunsford, L Dade; Liu, Kang-Du

    2017-05-01

    OBJECTIVE Cavernous sinus hemangiomas (CSHs) are rare vascular tumors. A direct microsurgical approach usually results in massive hemorrhage and incomplete tumor resection. Although stereotactic radiosurgery (SRS) has emerged as a therapeutic alternative to microsurgery, outcome studies are few. Authors of the present study evaluated the role of SRS for CSH. METHODS An international multicenter study was conducted to review outcome data in 31 patients with CSH. Eleven patients had initial microsurgery before SRS, and the other 20 patients (64.5%) underwent Gamma Knife SRS as the primary management for their CSH. Median age at the time of radiosurgery was 47 years, and 77.4% of patients had cranial nerve dysfunction before SRS. Patients received a median tumor margin dose of 12.6 Gy (range 12-19 Gy) at a median isodose of 55%. RESULTS Tumor regression was confirmed by imaging in all 31 patients, and all patients had greater than 50% reduction in tumor volume at 6 months post-SRS. No patient had delayed tumor growth, new cranial neuropathy, visual function deterioration, adverse radiation effects, or hypopituitarism after SRS. Twenty-four patients had presented with cranial nerve disorders before SRS, and 6 (25%) of them had gradual improvement. Four (66.7%) of the 6 patients with orbital symptoms had symptomatic relief at the last follow-up. CONCLUSIONS Stereotactic radiosurgery was effective in reducing the volume of CSH and attaining long-term tumor control in all patients at a median of 40 months. The authors' experience suggests that SRS is a reasonable primary and adjuvant treatment modality for patients in whom a CSH is diagnosed.

  6. Performance Study of Salt Cavern Air Storage Based Non-Supplementary Fired Compressed Air Energy Storage System

    NASA Astrophysics Data System (ADS)

    Chen, Xiaotao; Song, Jie; Liang, Lixiao; Si, Yang; Wang, Le; Xue, Xiaodai

    2017-10-01

    Large-scale energy storage system (ESS) plays an important role in the planning and operation of smart grid and energy internet. Compressed air energy storage (CAES) is one of promising large-scale energy storage techniques. However, the high cost of the storage of compressed air and the low capacity remain to be solved. This paper proposes a novel non-supplementary fired compressed air energy storage system (NSF-CAES) based on salt cavern air storage to address the issues of air storage and the efficiency of CAES. Operating mechanisms of the proposed NSF-CAES are analysed based on thermodynamics principle. Key factors which has impact on the system storage efficiency are thoroughly explored. The energy storage efficiency of the proposed NSF-CAES system can be improved by reducing the maximum working pressure of the salt cavern and improving inlet air pressure of the turbine. Simulation results show that the electric-to-electric conversion efficiency of the proposed NSF-CAES can reach 63.29% with a maximum salt cavern working pressure of 9.5 MPa and 9 MPa inlet air pressure of the turbine, which is higher than the current commercial CAES plants.

  7. Transarterial Onyx Embolization for Patients with Cavernous Sinus Dural Arteriovenous Fistulas Who Have Failed Transvenous Embolization.

    PubMed

    Wen, Jun; Duan, Chuan-Zhi; Huang, Li-Jing; Zhang, Xin; He, Xu-Ying; Li, Xi-Feng

    2015-09-01

    Transvenous embolization is the treatment of choice for cavernous sinus dural arteriovenous fistulas (csDAVFs) despite occasional difficulty in transvenous catheterization. We reported our experience in the treatment of csDAVFs by transarterial Onyx embolization in patients who had failed transvenous catheterization. We reviewed the clinical and radiographic records of csDAVFs patients receiving transarterial Onyx embolization after failed transvenous Onyx embolization at our institution over a period of 31 months. Success was defined as complete or near complete occlusion upon angiographic examination. In seven cases, the microcatheter failed to reach the cavernous sinus; in the remaining case, the internal jugular vein was occlusive. Eight sessions of the embolization and catheterization procedures via the arterial routes were conducted. Among them, five cases via the middle meningeal artery and the other three via the accessory meningeal artery. Angiography, immediately after embolization, revealed complete occlusion in seven cases (87.5 %) and partial occlusion in the remaining case. Angiographic follow-up (range, 6-10 months) showed that all patients achieved complete embolization. In cases where transvenous embolization of the cavernous sinus is difficult, transarterial embolization of the fistulas offers a safe and effective alternative.

  8. Orbital complications in children: differential diagnosis of a challenging disease.

    PubMed

    Welkoborsky, Hans-J; Graß, Sylvia; Deichmüller, Cordula; Bertram, Oliver; Hinni, Michael L

    2015-05-01

    Orbital swelling in children presents diagnostic and therapeutic challenges. Most are associated with acute sinusitis with complicating factors possibly including: amaurosis, meningitis, intracranial abscess or even cavernous sinus thrombosis. However not all acute orbital swelling is associated with acute sinusitis. A careful evaluation is critical prior to initiating therapy. Clinical records of 49 children (27 girls, 22 boys, with an average age of 11.8 years) were retrospectively reviewed. Historical data evaluated included all available information from parents and previous treating physicians. All patients underwent intensive pediatric, ophthalmologic, and otorhinolaryngologic examinations. Computed tomography (CT scans) were additionally performed in 40 % of children. The results of any examinations were also evaluated. Eighteen of the 49 patients had an orbital complication due to acute sinusitis. All 18 had elevated body temperature, C-Reactive Protein (CRP) values and white blood cell counts. Endoscopy of the nose revealed pus in the middle meatus in each case. According to Chandlers' classification, ten children presented with a preseptal, and eight children had a postseptal orbital cellulitis. All patients were admitted to the hospital and treated with intravenous antibiotics. CT scans further demonstrated signs of subperiostal abscess in four children. Functional endoscopic sinus surgery (FESS) was required in six children, including all patients with subperiostal abscess. Twenty children experienced orbital swelling unrelated to acute sinusitis, i.e. atheroma, inflammed insect stings, dental related abscess, conjunctivitis, and Herpes simplex associated superinfection. In three children, acute orbital swelling was caused by an orbital tumor. Orbital complications of an acute sinusitis occur often in the pediatric patient group, and most of these patients can be treated conservative with intravenous antibiotics. Indications for FESS include failure to

  9. Asymptotic solution of the problem for a thin axisymmetric cavern

    NASA Technical Reports Server (NTRS)

    Serebriakov, V. V.

    1973-01-01

    The boundary value problem which describes the axisymmetric separation of the flow around a body by a stationary infinite stream is considered. It is understood that the cavitation number varies over the length of the cavern. Using the asymptotic expansions for the potential of a thin body, the orders of magnitude of terms in the equations of the problem are estimated. Neglecting small quantities, a simplified boundary value problem is obtained.

  10. Cavernous sinus tuberculoma mimicking a neoplasm: Case report, literature review, and diagnostic and treatment suggestions for tuberculomas in rare locations

    PubMed Central

    Jaimovich, Sebastián G.; Thea, Victor Castillo; Guevara, Martin; Gardella, Javier L.

    2013-01-01

    Background: Cavernous sinus tuberculomas are extremely rare, but the increasing incidence worldwide of central nervous system (CNS) tuberculosis, mostly due to human immunodeficiency virus and poor sanitary conditions, and the ability of tuberculomas to mimic a brain neoplasm makes cavernous sinus tuberculomas a suspicious pathologic finding in the differential diagnosis of a brain space-occupying lesion. Case Description: We present an immunocompetent patient with no signs of systemic tuberculosis and an isolated right cavernous sinus space-occupying lesion. A skull base approach was performed and tumor resection achieved. The postoperative course was uneventful. Pathologic findings consisted of a tuberculoma and antituberculous treatment was immediately begun with total tumor regression after a 12-month regimen. After reviewing the literature, we propose suggestions to orient the diagnosis and a treatment algorithm for tuberculomas in rare locations. Conclusion: Tuberculomas in rare locations, as the cavernous sinus, are a challenging pathology as they have the ability to mimic a brain neoplasm. Although first line treatment are antituberculous therapy (4 drugs for at least 12 months) and adjuvant steroids, in inconclusive cases, surgical biopsy or excision is recommended for histopathologic confirmation and to reduce the mass effect, always following with antituberculous therapy and adjuvant steroids. PMID:24381801

  11. Pure Epidural Cavernous Hemangioma of the Cervical Spine that Presented with an Acute Sensory Deficit Caused by Hemorrhage

    PubMed Central

    Lee, Sang-Ho; Chung, Seung-Eun; Paeng, Sung-Suk; Kim, Hye-Sung; Yoon, Sang-Wook; Yu, Jeong-Sik

    2006-01-01

    Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI. PMID:17191320

  12. Pure epidural cavernous hemangioma of the cervical spine that presented with an acute sensory deficit caused by hemorrhage.

    PubMed

    Jo, Byung-June; Lee, Sang-Ho; Chung, Seung-Eun; Paeng, Sung-Suk; Kim, Hye-Sung; Yoon, Sang-Wook; Yu, Jeong-Sik

    2006-12-31

    Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.

  13. Lateral sellar compartment O.T. (cavernous sinus): history, anatomy, terminology.

    PubMed

    Parkinson, D

    1998-08-01

    Claudios Galen (119-199 a.d.) dissected lower animals with parasellar carotid retia bathed in venous blood and transposed his findings to human anatomy. Andreas Vesalius (1514-1564) corrected most of Galen's errors but apparently never looked into this small, extradural compartment, nor, apparently, did Winslow (Exposition Anatomique de la Structure du Corps Humain. London: N. Prevast, 1734), who christened it the "cavernous sinus," (CS) presumably thinking that it would resemble the corpora cavernosa of the penis. Multiple surgical explorations, gross dissections, microscopic views, and vascular casts from early fetuses to an 81 year old have been examined and reviewed. The CS is not a dural sinus nor is it cavernous. The compartment is extradural, and the venous structures contained within consist of a greatly variable plexus of extremely thin-walled veins. The name, CS, is a barrier to the understanding of the structure and function of this extradural anatomical jewel box, which contains fat, myelinated and nonmyelinated nerves, arteries, and a plexus of veins. It is proposed that this name be changed, because it is inaccurate and misleading. The replacement should leave no doubt about its meaning. The lateral sellar compartment is descriptive and accurate. The veins within are a parasellar plexus.

  14. [Cavernous sinus thrombosis as a rare cause of exophthalmos in childhood : A case report].

    PubMed

    Kamawal, A; Schmidt, M A; Rompel, O; Gusek-Schneider, G C; Mardin, C Y; Trollmann, R

    2017-05-01

    Complications of acute bacterial sinusitis mostly occur in children and adolescents. In particular, intracranial spread of the infection can lead to severe even fatal courses of the disease. This article is a case report about a 13-year-old boy suffering from left-sided headache, meningismus and exophthalmos as presenting symptoms. Cranial magnetic resonance imaging (MRI) showed merely right-sided sphenoid sinusitis; however, the diffusion-weighted MRI sequence indicated a left-sided cavernous sinus thrombosis, which could be confirmed by computed tomography (CT) angiography. Cerebrospinal fluid diagnostics showed significant leukocytosis confirming secondary meningitis. Finally, exophthalmos was explained by parainfectious cavernous sinus thrombosis and periorbital edema. This case report highlights the importance of extended and specific diagnostic imaging in cases of clinically suspected complications in children and adolescents with sinusitis and the diagnostic significance of diffusion-weighted MRI.

  15. [Septic thrombosis of the cavernous sinus due to folliculitis].

    PubMed

    Tuettenberg, A; Tuettenberg, J; Knop, J; Enk, A

    2003-04-01

    Sinus thrombosis is an acute life-threatening disease. While cavernous sinus thrombosis secondary to facial infections is described in the literature, it is uncommon. The key clinical characteristics are a facial infection, headache, chemosis and edema of the eyelid. The main differential diagnostic consideration is meningoencephalitis. Early diagnosis by angiography, magnetic resonance imaging and examination of CSF is important as treatment should be initiated as soon as possible in order to decrease morbidity and mortality. The mainstays of therapy are heparinization and appropriate intravenous antibiotic therapy.

  16. SU-E-I-91: Quantitative Assessment of Early Hepatocellular Carcinoma and Cavernous Hemangioma of Live Using In-Line Phase-Contrast X-Ray Imaging

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

    Duan, J

    Purpose: To investigate the potential utility of in-line phase-contrast imaging (ILPCI) technique with synchrotron radiation in detecting early hepatocellular carcinoma and cavernous hemangioma of live using in vitro model system. Methods: Without contrast agents, three typical early hepatocellular carcinoma specimens and three typical cavernous hemangioma of live specimens were imaged using ILPCI. To quantitatively discriminate early hepatocellular carcinoma tissues and cavernous hemangioma tissues, the projection images texture feature based on gray level co-occurrence matrix (GLCM) were extracted. The texture parameters of energy, inertia, entropy, correlation, sum average, sum entropy, difference average, difference entropy and inverse difference moment, were obtained respectively.more » Results: In the ILPCI planar images of early hepatocellular carcinoma specimens, vessel trees were clearly visualized on the micrometer scale. Obvious distortion deformation was presented, and the vessel mostly appeared as a ‘dry stick’. Liver textures appeared not regularly. In the ILPCI planar images of cavernous hemangioma of live specimens, typical vessels had not been found compared with the early hepatocellular carcinoma planar images. The planar images of cavernous hemangioma of live specimens clearly displayed the dilated hepatic sinusoids with the diameter of less than 100 microns, but all of them were overlapped with each other. The texture parameters of energy, inertia, entropy, correlation, sum average, sum entropy, and difference average, showed a statistically significant between the two types specimens image (P<0.01), except the texture parameters of difference entropy and inverse difference moment(P>0.01). Conclusion: The results indicate that there are obvious changes in morphological levels including vessel structures and liver textures. The study proves that this imaging technique has a potential value in evaluating early hepatocellular carcinoma and

  17. Intralesional hemorrhage and thrombosis without rupture in a pure spinal epidural cavernous angioma: a rare cause of acute lumbal radiculopathy

    PubMed Central

    Riemenschneider, Markus; Herdmann, Jörg

    2010-01-01

    Pure spinal epidural cavernous angiomas are extremely rare lesions, and their normal shape is that of a fusiform mass in the dorsal aspects of the spinal canal. We report a case of a lumbo-sacral epidural cavernous vascular malformation presenting with acute onset of right-sided S1 radiculopathy. Clinical aspects, imaging, intraoperative findings, and histology are demonstrated. The patient, a 27-year-old man presented with acute onset of pain, paraesthesia, and numbness within the right leg corresponding to the S1 segment. An acute lumbosacral disc herniation was suspected, but MRI revealed a cystic lesion with the shape of a balloon, a fluid level and a thickened contrast-enhancing wall. Intraoperatively, a purple-blue tumor with fibrous adhesions was located between the right S1 and S2 nerve roots. Macroscopically, no signs of epidural bleedings could be denoted. After coagulation of a reticular venous feeder network and dissection of the adhesions the rubber ball-like lesion was resected in total. Histology revealed a prominent venous vessel with a pathologically thickened, amuscular wall surrounded by smaller, hyalinized, venous vessels arranged in a back-to-back position typical for the diagnosis of a cavernous angioma. Lumina were partially occluded by thrombi. The surrounding fibrotic tissue showed signs of recurrent bleedings. There was no obvious mass hemorrhage into the surrounding tissue. In this unique case, the pathologic mechanism was not the usual rupture of the cavernous angioma with subsequent intraspinal hemorrhage, but acute mass effect by intralesional bleedings and thrombosis with subsequent increase of volume leading to nerve root compression. Thus, even without a sudden intraspinal hemorrhage a spinal cavernous malformation can cause acute symptoms identical to the clinical features of a soft disc herniation. PMID:20213297

  18. A rare case of important and recurrent abnormal uterine bleeding in a post partum woman caused by cavernous hemangioma: a case report and review of literature.

    PubMed

    Aka, Kacou Edele; Apollinaire Horo, Gninlgninrin; Fomba, Minata; Kouyate, Salif; Koffi, Abdoul Koffi; Konan, Seni; Fanny, Mohamed; Effi, Benjamin; Kone, Mamourou

    2017-01-01

    The cavernous hemangioma is a rare benign vascular tumor. About 50 cases of this disease were found in the literature over the last century and only 9 cases of cavernous hemangioma on the pregnant uterus were published it comes into cavernous or capillary form. The symptomatology is not unequivocal and when it occurs during pregnancy or postpartum, it causes life-threatening cataclysmic hemorrhage. Antenatal diagnosis is difficult and requires a multidisciplinary approach with pathologists, radiologists and gynecologists to avoid these complications or unnecessary hysterectomies. The diagnosis is histological. Hysterectomy is possible after failure of conservative treatment means. We report a rare case, a novel mixed cavernous hemangioma of the body associated with a capillary hemangioma of the cervix in a patient of 28 years 5th visors with recurrent genital bleeding in the postpartum period leading to a hysterectomy.

  19. Cavernous sinus hemangioma: a fourteen year single institution experience.

    PubMed

    Bansal, Sumit; Suri, Ashish; Singh, Manmohan; Kale, Shashank Sharad; Agarwal, Deepak; Sharma, Manish Singh; Mahapatra, Ashok Kumar; Sharma, Bhawani Shankar

    2014-06-01

    Cavernous sinus hemangioma (CSH) is a rare extra-axial vascular neoplasm that accounts for 2% to 3% of all cavernous sinus tumors. Their location, propensity for profuse bleeding during surgery, and relationship to complex neurovascular structures are factors which present difficulty in excising these lesions. The authors describe their experience of 22 patients with CSH over 14 years at a tertiary care center. Patients were managed with microsurgical resection using a purely extradural transcavernous approach (13 patients) and with Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden) (nine patients). Retrospective data analysis found headache and visual impairment were the most common presenting complaints, followed by facial hypesthesia and diplopia. All but one patient had complete tumor excision in the surgical series. Transient ophthalmoparesis (complete resolution in 6-8 weeks) was the most common surgical complication. In the GKRS group, marked tumor shrinkage (>50% tumor volume reduction) was achieved in two patients, slight shrinkage in five and no change in two patients, with symptom improvement in the majority of patients. To our knowledge, we describe one of the largest series of CSH managed at a single center. Although microsurgical resection using an extradural transcavernous approach is considered the treatment of choice in CSH and allows complete excision with minimal mortality and long-term morbidity, GKRS is an additional tool for treating residual symptomatic lesions or in patients with associated comorbidities making surgical resection unsuitable. Copyright © 2013. Published by Elsevier Ltd.

  20. Environmental change at Kartchner Caverns: trying to separate natural and anthropogenic changes

    Treesearch

    Rickard S. Toomey; Ginger Nolan

    2005-01-01

    Cave temperature and moisture levels are important factors in the environmental health of Kartchner Caverns. Monitoring indicates the cave has warmed and moisture levels have fallen over the past 14 years. Timing and patterns of change within the cave suggest that changes are due to development as a show cave. However, changes in other caves, surface temperature and...

  1. Limited endoscopic transsphenoidal approach for cavernous sinus biopsy: illustration of 3 cases and discussion.

    PubMed

    Graillon, T; Fuentes, S; Metellus, P; Adetchessi, T; Gras, R; Dufour, H

    2014-01-01

    Advances in transsphenoidal surgery and endoscopic techniques have opened new perspectives for cavernous sinus (CS) approaches. The aim of this study was to assess the advantages and disadvantages of limited endoscopic transsphenoidal approach, as performed in pituitary adenoma surgery, for CS tumor biopsy illustrated with three clinical cases. The first case was a 46-year-old woman with a prior medical history of parotid adenocarcinoma successfully treated 10 years previously. The cavernous sinus tumor was revealed by right third and sixth nerve palsy and increased over the past three years. A tumor biopsy using a limited endoscopic transsphenoidal approach revealed an adenocarcinoma metastasis. Complementary radiosurgery was performed. The second case was a 36-year-old woman who consulted for diplopia with right sixth nerve palsy and amenorrhea with hyperprolactinemia. Dopamine agonist treatment was used to restore the patient's menstrual cycle. Cerebral magnetic resonance imaging (MRI) revealed a right sided CS tumor. CS biopsy, via a limited endoscopic transsphenoidal approach, confirmed a meningothelial grade 1 meningioma. Complementary radiosurgery was performed. The third case was a 63-year-old woman with progressive installation of left third nerve palsy and visual acuity loss, revealing a left cavernous sinus tumor invading the optic canal. Surgical biopsy was performed using an enlarged endoscopic transsphenoidal approach to the decompress optic nerve. Biopsy results revealed a meningothelial grade 1 meningioma. Complementary radiotherapy was performed. In these three cases, no complications were observed. Mean hospitalization duration was 4 days. Reported anatomical studies and clinical series have shown the feasibility of reaching the cavernous sinus using an endoscopic endonasal approach. Trans-foramen ovale CS percutaneous biopsy is an interesting procedure but only provides cell analysis results, and not tissue analysis. However, radiotherapy and

  2. The Usefulness of Diffusion Tensor Imaging and Tractography in Surgery of Brainstem Cavernous Malformations.

    PubMed

    Januszewski, Jacob; Albert, Lauren; Black, Karen; Dehdashti, Amir R

    2016-09-01

    Diffusion tensor imaging (DTI) estimates the course and connectivity patterns of white matter tracts. The objective of this study is to evaluate whether findings in the brain stem modify the preoperative surgical trajectory planning or postoperative outcome in patients with brain stem cavernous malformations. Ten patients with symptomatic brainstem cavernous malformation underwent surgical resection. Five patients received preoperative DTI evaluation and the remaining 5 did not. Reconstructed DTI tracts consisted of corticospinal, medial lemnisci, and cerebellar peduncles. The surgical planning and postoperative outcome were evaluated. In 5 patients with no preoperative DTI evaluation, surgical planning was based on anatomic landmark and the 2-point technique. The other 5 patients underwent preoperative DTI, and findings were factored into the selection of the surgical approach. In 3 of the 5 cases with DTI evaluation, the 2-point technique suggested a similar trajectory. In the other 2, the DTI findings suggested a different approach to avoid damage to the white matter tract. Two patients in the group with no DTI had immediate postoperative new or worsened deficit, which improved at long-term follow-up. No patient in the DTI group had a new neurologic deficit. Compared with the standard magnetic resonance imaging, DTI provided improved visualization of cavernous malformation involvement in eloquent fiber tracts of the brainstem. This additional information might help in selecting a more appropriate surgical trajectory in selected lesions. Larger patient cohorts are needed to assess the effect of this modality in patients' outcome. Published by Elsevier Inc.

  3. Dumbbell-Shaped Epidural Cavernous Hemangioma in the Thoracic Spine Mimicking Schwannoma.

    PubMed

    Wang, Shantao; Wang, Mingwei; Wang, Fuchao; Yuan, Xunhui; Xiao, Hang; Bai, Yun'an; Liu, Fucun

    2016-10-01

    Dumbbell-shaped epidural cavernous hemangiomas (CHs) are extremely rare, and they are easily misdiagnosed as spinal schwannomas. Herein, the authors report 1 rare case of dumbbell-shaped epidural CH in the thoracic spine. To the best of our knowledge, only a few cases of dumbbell-shaped epidural CHs in thoracic spine have been reported. Furthermore, the clinical characteristics and treatments for spinal epidural CHs were investigated and reviewed.

  4. Micro-Macro Analysis and Phenomenological Modelling of Salt Viscous Damage and Application to Salt Caverns

    NASA Astrophysics Data System (ADS)

    Zhu, Cheng; Pouya, Ahmad; Arson, Chloé

    2015-11-01

    This paper aims to gain fundamental understanding of the microscopic mechanisms that control the transition between secondary and tertiary creep around salt caverns in typical geological storage conditions. We use a self-consistent inclusion-matrix model to homogenize the viscoplastic deformation of halite polycrystals and predict the number of broken grains in a Representative Elementary Volume of salt. We use this micro-macro modeling framework to simulate creep tests under various axial stresses, which gives us the critical viscoplastic strain at which grain breakage (i.e., tertiary creep) is expected to occur. The comparison of simulation results for short-term and long-term creep indicates that the initiation of tertiary creep depends on the stress and the viscoplastic strain. We use the critical viscoplastic deformation as a yield criterion to control the transition between secondary and tertiary creep in a phenomenological viscoplastic model, which we implement into the Finite Element Method program POROFIS. We model a 850-m-deep salt cavern of irregular shape, in axis-symmetric conditions. Simulations of cavern depressurization indicate that a strain-dependent damage evolution law is more suitable than a stress-dependent damage evolution law, because it avoids high damage concentrations and allows capturing the formation of a damaged zone around the cavity. The modeling framework explained in this paper is expected to provide new insights to link grain breakage to phenomenological damage variables used in Continuum Damage Mechanics.

  5. Trans-zygomatic middle cranial fossa approach to access lesions around the cavernous sinus and anterior parahippocampus: a minimally invasive skull base approach.

    PubMed

    Melamed, Itay; Tubbs, R Shane; Payner, Troy D; Cohen-Gadol, Aaron A

    2009-08-01

    Exposure of the cavernous sinus or anterior parahippocampus often involves a wide exposure of the temporal lobe and mobilization of the temporalis muscle associated with temporal lobe retraction. The authors present a cadaveric study to illustrate the feasibility, advantages and landmarks necessary to perform a trans-zygomatic middle fossa approach to lesions around the cavernous sinus and anterior parahippocampus. The authors performed bilateral trans-zygomatic middle fossae exposures to reach the cavernous sinus and parahippocampus in five cadavers (10 sides). We assessed the morbidity associated with this procedure and compared the indications, advantages, and disadvantages of this method versus more extensive skull base approaches. A vertical linear incision along the middle portion of the zygomatic arch was extended one finger breadth inferior to the inferior edge of the zygomatic arch. Careful dissection inferior to the arch allowed preservation of facial nerve branches. A zygomatic osteotomy was followed via a linear incision through the temporalis muscle and exposure of the middle cranial fossa floor. A craniotomy along the inferolateral temporal bone and middle fossa floor allowed extradural dissection along the middle fossa floor and exposure of the cavernous sinus including all three divisions of the trigeminal nerve. Intradural inspection demonstrated adequate exposure of the parahippocampus. Exposure of the latter required minimal or no retraction of the temporal lobe. The trans-zygomatic middle fossa approach is a simplified skull base exposure using a linear incision, which may avoid the invasivity of more extensive skull base approaches while providing an adequate corridor for resection of cavernous sinus and parahippocampus lesions. The advantages of this approach include its efficiency, ease, minimalism, preservation of the temporalis muscle, and minimal retraction of the temporal lobe.

  6. In Situ Observation of Failure Mechanisms Controlled by Rock Masses with Weak Interlayer Zones in Large Underground Cavern Excavations Under High Geostress

    NASA Astrophysics Data System (ADS)

    Duan, Shu-Qian; Feng, Xia-Ting; Jiang, Quan; Liu, Guo-Feng; Pei, Shu-Feng; Fan, Yi-Lin

    2017-09-01

    A weak interlayer zone (WIZ) is a poor rock mass system with loose structure, weak mechanical properties, variable thickness, random distribution, strong extension, and high risk due to the shear motion of rock masses under the action of tectonism, bringing many stability problems and geological hazards, especially representing a potential threat to the overall stability of rock masses with WIZs in large underground cavern excavations. Focusing on the deformation and failure problems encountered in the process of excavation unloading, this research proposes comprehensive in situ observation schemes for rock masses with WIZs in large underground cavern on the basis of the collection of geological, construction, monitoring, and testing data. The schemes have been fully applied in two valuable project cases of an underground cavern group under construction in the southwest of China, including the plastic squeezing-out tensile failure and the structural stress-induced collapse of rock masses with WIZs. In this way, the development of rock mass failure, affected by the step-by-step excavations along the cavern's axis and the subsequent excavation downward, could be observed thoroughly. Furthermore, this paper reveals the preliminary analyses of failure mechanism of rock masses with WIZs from several aspects, including rock mass structure, strength, high stress, ground water effects, and microfracture mechanisms. Finally, the failure particularities of rock masses with WIZs and rethink on prevention and control of failures are discussed. The research results could provide important guiding reference value for stability analysis, as well as for rethinking the excavation and support optimization of rock masses with WIZs in similar large underground cavern under high geostress.

  7. Evoked Cavernous Activity: Normal Values

    PubMed Central

    Yang, Claire C.; Yilmaz, Ugur; Vicars, Brenda G.

    2009-01-01

    Purpose We present normative data for evoked cavernous activity (ECA), an electrodiagnostic test that evaluates the autonomic innervation of the corpora cavernosa. Material and Methods We enrolled 37 healthy, sexually active and potent men for the study. Each subject completed an IIEF questionnaire and underwent simultaneous ECA and hand and foot sympathetic skin response (SSR) testing. The sympathetic skin response tests were performed as autonomic controls. Results Thirty six men had discernible ECA and SSRs. The mean IIEF erectile domain score was 27. ECA is a low frequency wave that is morphologically and temporally similar in both corpora. The amplitudes of the responses were highly variable. The latencies, although variable, always occurred after the hand SSR. There was no change in the quality or the latency of the ECA with age. Conclusions ECA is measurable in healthy, potent men in a wide range of ages. Similar to other evoked responses of the autonomic nervous system, the measured waveform is highly variable, but its presence is consistent. The association between ECA and erectile function is to be determined. PMID:18423763

  8. The role of magnetic resonance diffusion-weighted imaging and three-dimensional arterial spin labelling perfusion imaging in the differentiation of parasellar meningioma and cavernous haemangioma.

    PubMed

    Xiao, Hua-Feng; Lou, Xin; Liu, Meng-Yu; Wang, Yu-Lin; Wang, Yan; Chen, Zhi-Ye; Shi, Kai-Ning; Ma, Lin

    2014-08-01

    To evaluate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) and three-dimensional arterial spin labelling perfusion imaging (3D-ASL) in distinguishing cavernous haemangioma from parasellar meningioma, using histological data as a reference standard. Patients with parasellar meningioma or parasellar cavernous haemangioma underwent conventional T1- and T2-weighted magnetic resonance imaging (MRI) followed by DWI and 3D-ASL using a 3.0 Tesla MRI. The minimum apparent diffusion coefficient (minADC) from DWI and the maximal normalized cerebral blood flow (nCBF) from 3D-ASL were measured in each tumour. Diagnosis was confirmed by histology. MinADC was significantly lower and nCBF significantly higher in meningioma (n = 19) than cavernous haemangioma (n = 15). There was a significant negative correlation between minADC and nCBF (r = -0.605). DWI and 3D-ASL are useful in differentiating cavernous haemangiomas from parasellar meningiomas, particularly in situations when the appearance on conventional MRI sequences is otherwise ambiguous. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  9. Extensive basal ganglia edema caused by a traumatic carotid-cavernous fistula: a rare presentation related to a basal vein of Rosenthal anatomical variation.

    PubMed

    Ract, Isabelle; Drier, Aurélie; Leclercq, Delphine; Sourour, Nader; Gabrieli, Joseph; Yger, Marion; Nouet, Aurélien; Dormont, Didier; Chiras, Jacques; Clarençon, Frédéric

    2014-07-01

    The authors report a very rare presentation of traumatic carotid-cavernous fistula (CCF) with extensive edema of the basal ganglia and brainstem because of an anatomical variation of the basal vein of Rosenthal (BVR). A 45-year-old woman was admitted to the authors' institution for left hemiparesis, dysarthria, and a comatose state caused by right orbital trauma from a thin metal rod. Brain MRI showed a right CCF and vasogenic edema of the right side of the brainstem, right temporal lobe, and basal ganglia. Digital subtraction angiography confirmed a high-flow direct CCF and revealed a hypoplastic second segment of the BVR responsible for the hypertension in inferior striate veins and venous congestion. Endovascular treatment was performed on an emergency basis. One month after treatment, the patient's symptoms and MRI signal abnormalities almost totally disappeared. Basal ganglia and brainstem venous congestion may occur in traumatic CCF in cases of a hypoplastic or agenetic second segment of the BVR and may provoke emergency treatment.

  10. Surgical management of brain-stem cavernous malformations: report of 137 cases.

    PubMed

    Wang, Chung-cheng; Liu, Ali; Zhang, Jun-ting; Sun, Bo; Zhao, Yuan-li

    2003-06-01

    With the improvement in neuroimaging and microsurgical techniques, brain stem cavernous malformations are no longer considered inoperable. Surgical indications for brainstem cavernoma are evolving, with better understanding of its natural history and decreasing surgical complications. During 1986 through 1998, a series of 137 patients (4 patients each with two brain stem lesions, total number of lesions, 141) with brain stem cavernous malformations were treated microsurgically at Beijing Neurosurgery Institute. The age distribution, lesion location, and clinical presentations were analyzed. The bleeding rate, surgical indications and microsurgical techniques were also discussed. In our series, 92 of 137 cases (67.2%) suffered more than one hemorrhage. Female patients had a higher risk of recurrent hemorrhage than that of male patients. Unlike cavernomas malformations from other locations, repeated hemorrhages from brain stem malformations are much more common and usually lead to new neurologic deficits. Among all 137 surgically treated patients, there was no operative mortality. Ninety-nine patients (72.3%) either improved or remained clinically stable postoperatively. The size of the cavernoma/hematoma does not necessarily correlate with the surgical result. While the acute hematoma can facilitate the surgical dissection, longer clinical history with multiple hemorrhages often makes total surgical resection difficult, partially because of the firmer capsule that may not shrink or collapse after hematoma is released. Pathologically those capsules were associated with more hyaline degeneration, fibrous proliferation and even calcifications. During the follow-up period between 0.5 to 11 years in 129 cases, 115 patients (89.2%) have been working, studying, or doing house work. Three patients (2.3%) suffered recurrent hemorrhages. Surgical indications of brain stem cavernoma include (1) progressive neurologic deficits; (2) overt acute or subacute hemorrhage on MRI

  11. [Depiction of the cranial nerves around the cavernous sinus by 3D reversed FISP with diffusion weighted imaging (3D PSIF-DWI)].

    PubMed

    Ishida, Go; Oishi, Makoto; Jinguji, Shinya; Yoneoka, Yuichiro; Sato, Mitsuya; Fujii, Yukihiko

    2011-10-01

    To evaluate the anatomy of cranial nerves running in and around the cavernous sinus, we employed three-dimensional reversed fast imaging with steady-state precession (FISP) with diffusion weighted imaging (3D PSIF-DWI) on 3-T magnetic resonance (MR) system. After determining the proper parameters to obtain sufficient resolution of 3D PSIF-DWI, we collected imaging data of 20-side cavernous regions in 10 normal subjects. 3D PSIF-DWI provided high contrast between the cranial nerves and other soft tissues, fluid, and blood in all subjects. We also created volume-rendered images of 3D PSIF-DWI and anatomically evaluated the reliability of visualizing optic, oculomotor, trochlear, trigeminal, and abducens nerves on 3D PSIF-DWI. All 20 sets of cranial nerves were visualized and 12 trochlear nerves and 6 abducens nerves were partially identified. We also presented preliminary clinical experiences in two cases with pituitary adenomas. The anatomical relationship between the tumor and cranial nerves running in and around the cavernous sinus could be three-dimensionally comprehended by 3D PSIF-DWI and the volume-rendered images. In conclusion, 3D PSIF-DWI has great potential to provide high resolution "cranial nerve imaging", which visualizes the whole length of the cranial nerves including the parts in the blood flow as in the cavernous sinus region.

  12. Genetically diagnosed Birt-Hogg-Dubé syndrome and familial cerebral cavernous malformations in the same individual: a case report.

    PubMed

    Whitworth, James; Stausbøl-Grøn, Brian; Skytte, Anne-Bine

    2017-01-01

    When faced with an unusual clinical feature in a patient with a Mendelian disorder, the clinician may entertain the possibilities of either the feature representing a novel manifestation of that disorder or the co-existence of a different inherited condition. Here we describe an individual with a submandibular oncocytoma, pulmonary bullae and renal cysts as well as multiple cerebral cavernous malformations and haemangiomas. Genetic investigations revealed constitutional mutations in FLCN, associated with Birt-Hogg-Dubé syndrome (BHD) and CCM2, associated with familial cerebral cavernous malformation. Intracranial vascular pathologies (but not cerebral cavernous malformation) have recently been described in a number of individuals with BHD (Kapoor et al. in Fam Cancer 14:595-597, 10.1007/s10689-015-9807-y , 2015) but it is not yet clear whether they represent a genuine part of that conditions' phenotypic spectrum. We suggest that in such instances of potentially novel clinical features, more extensive genetic testing to consider co-existing conditions should be considered where available. The increased use of next generation sequencing applications in diagnostic settings is likely to lead more cases such as this being revealed.

  13. Hydatid liver cyst causing portal vein thrombosis and cavernous transformation: a case report and literature review

    PubMed Central

    Kirmizi, Serdar; Kayaalp, Cuneyt; Yilmaz, Sezai

    2016-01-01

    A 33-year-old male with abdominal distention after meals was admitted to the hospital. He had a history of surgery for hydatid liver cyst. The cyst was located at the liver hilum and there were portal venous thrombosis and cavernous transformation. It had been treated with partial cystectomy, omentoplasty and albendazole. Two years later at the admission to our center, his laboratory tests were in normal ranges. Abdominal imaging methods revealed splenomegaly, portal vein thrombosis, cavernous transformation and the previously operated hydatid liver cyst. Upper gastrointestinal endoscopy demonstrated esophageal and gastric fundal varices. Due to his young age and low risk for surgery, the patient was planned for surgical treatment of both pathologies at the same time. At laparotomy, hydatid liver cyst was obliterated with omentum and there was no sign of active viable hydatid disease. A meso-caval shunt with an 8 mm in-diameter graft was created. In the postoperative period, his symptoms and endoscopic varices were regressed. There were four similar cases reported in the literature. This one was the youngest and the only one treated by a surgical shunt. Hydatid liver cysts that located around the hilum can lead to portal vein thrombosis and cavernous thrombosis. Treatment should consist of both hydatid liver cyst and portal hypertension. To the best of our knowledge, this was the first case of surgically treated portal vein thrombosis that was originated from a hydatid liver cyst. PMID:27895860

  14. Efficacy of transsphenoidal surgery in achieving biochemical cure of growth hormone-secreting pituitary adenomas among patients with cavernous sinus invasion: a systematic review and meta-analysis.

    PubMed

    Briceno, Vanessa; Zaidi, Hasan A; Doucette, Joanne A; Onomichi, Kaho B; Alreshidi, Amer; Mekary, Rania A; Smith, Timothy R

    2017-05-01

    Growth hormone-secreting pituitary adenomas in adults can result in severe craniofacial disfigurement and potentially fatal medical complications. Surgical resection leading to remission of the disease is dependent on complete surgical resection of the tumor. Lesions that invade the cavernous sinus may not be safely accessible via an endonasal transsphenoidal surgery (TSS), and the rates of biochemical remission of patients with residual disease vary widely in the literature. We conducted a meta-analysis to examine the prevalence of biochemical remission after TSS among patients with growth hormone-secreting pituitary adenomas with and without cavernous sinus invasion. Embase, PubMed, and Cochrane Library databases were searched for relevant publications. Fourteen studies with 972 patients with biochemically confirmed growth hormone-secreting pituitary adenomas were included in the meta-analysis. The overall remission prevalence under a fixed-effect model was 47.6% (95% CI = 40.8-54.4%) for patients with invasive macroadenomas (I 2  = 74.6%, p < 0.01); 76.4% (95% CI = 72.2-80.1%) for patients with non-invasive macroadenomas (I 2  = 59.6%, p = 0.03); and 74.2% (95% CI = 66.3-80.7%) for patients with non-invasive microadenomas (I 2  = 36.4, p = 0.10). The significant difference among the three groups resulted from the difference between patients with or without cavernous sinus invasion (p = 0.01) and not from the size of adenomas among those without cavernous sinus invasion (p = 0.66). The prevalence of biochemical remission in patients with cavernous sinus invasion was lower than in patients without cavernous sinus invasion after TSS for acromegaly.

  15. [A case of cavernous angioma at the convexity in the dura mater: characteristics of images in the literature].

    PubMed

    Yonezawa, Ushio; Ikawa, Fusao; Hamasaki, Osamu; Hidaka, Toshikazu; Kurokawa, Yasuharu; Onuma, Hideyuki

    2014-08-01

    We describe a rare case of cavernous angioma in the dura mater and discuss published MRI findings on similar cases. The patient was a 78-year-old woman who was referred to Shimane Prefectural Central Hospital with complaints of headaches. We were subsequently able to identify a tumor at the convexity in the dura mater. The tumor showed a high intensity on T2-weighted images and was heterogeneously enhanced on contrast-enhanced T1-weighted images. The maximum size of the tumor was 35 mm. Moreover, preoperative angiography showed a slight vascularity in the tumor. We performed surgery with the expectation of finding a meningioma, metastatic brain tumor, or another mesenchymal tumor. The tumor was dark and red, attached to the dura mater, and adhered to the arachnoid. However, we were able to peel the tumor away from the meninges and achieved a total removal of the mass, successfully cutting a fine feeding cortical artery. The patient was discharged without neurological defects 9 days after surgery;the pathological diagnosis was cavernous angioma. In conclusion, it is difficult to discern between meningioma and cavernous angioma in the dura mater. However, the specificity of high intensity on T2-weighted images is relatively high, and preoperative diagnosis can be determined by MRI and angiography findings.

  16. The effect of different antihypertensive drugs on cavernous tissue in experimental chronic renal insufficiency.

    PubMed

    Toblli, Jorge E; Stella, Inés; Mazza, Osvaldo N; Ferder, León; Inserra, Felipe

    2006-01-01

    Male erectile dysfunction increases in prevalence in patients with severe chronic renal failure. Since arterial hypertension induces significant damage in cavernous tissue (CT), and considering that hypertension is extremely common in patients with end-stage renal disease (ESRD), the aim of this study was to evaluate the effect of the most conventionally employed antihypertensive drugs on CT in a rat model of renal insufficiency. Five groups of male rats with subtotal nephrectomy (STNx) and 1 with sham operations were studied over 6 months: STNx without treatment, STNx with benazepril (BZ), STNx with losartan (LS), STNx with amlodipine (AML) and STNx with atenolol (AT) plus the sham group. All rats were sacrificed at 6 months after STNx, and penises processed for LM and immunohistochemical studies. Cavernous smooth muscle (CSM) and vascular smooth muscle (VSM) from cavernous arteries and the amount of collagen type III were evaluated. All groups with antihypertensive drugs showed similar control in blood pressure throughout the study. Un-treated STNx, STNx with AML and STNx with AT presented significant (p<0.01) hypertrophy in both VSM and CSM, together with an increased amount of collagen type III in CT. Conversely, STNx with either BZ or LS showed a substantial (p<0.01) reduction in all of these variables, with values not different from the sham group. There was a significant (p<0.01) negative correlation between creatinine clearance and the amount of VSM, CSM and collagen type III deposition in CT in untreated STNx, STNx with AML and STNx with AT, but not in STNx with BZ, STNx with LS and sham. These results suggest that the interactions against the renin-angiotensin system (RAS) either by ACE inhibitors or angiotensin AT1 receptor blockers produce considerable benefits regarding structural abnormalities in CT in this animal model of renal insufficiency beyond blood pressure control.

  17. Reliability analysis of hydrologic containment of liquefied petroleum gas within unlined rock caverns.

    NASA Astrophysics Data System (ADS)

    Gao, X.; Yan, E. C.; Yeh, T. C. J.; Wang, Y.; Liang, Y.; Hao, Y.

    2017-12-01

    Notice that most of the underground liquefied petroleum gas (LPG) storage caverns are constructed in unlined rock caverns (URCs), where the variability of hydraulic properties (in particular, hydraulic conductivity) has significant impacts on hydrologic containment performance. However, it is practically impossible to characterize the spatial distribution of these properties in detail at the site of URCs. This dilemma forces us to cope with uncertainty in our evaluations of gas containment. As a consequence, the uncertainty-based analysis is deemed more appropriate than the traditional deterministic analysis. The objectives of this paper are 1) to introduce a numerical first order method to calculate the gas containment reliability within a heterogeneous, two-dimensional unlined rock caverns, and 2) to suggest a strategy for improving the gas containment reliability. In order to achieve these goals, we first introduced the stochastic continuum representation of saturated hydraulic conductivity (Ks) of fractured rock and analyzed the spatial variability of Ks at a field site. We then conducted deterministic simulations to demonstrate the importance of heterogeneity of Ks in the analysis of gas tightness performance of URCs. Considering the uncertainty of the heterogeneity in the real world situations, we subsequently developed a numerical first order method (NFOM) to determine the gas tightness reliability at crucial locations of URCs. Using the NFOM, the effect of spatial variability of Ks on gas tightness reliability was investigated. Results show that as variance or spatial structure anisotropy of Ks increases, most of the gas tightness reliability at crucial locations reduces. Meanwhile, we compare the results of NFOM with those of Monte Carlo simulation, and we find the accuracy of NFOM is mainly affected by the magnitude of the variance of Ks. At last, for improving gas containment reliability at crucial locations at this study site, we suggest that vertical

  18. Interactive evolution concept for analyzing a rock salt cavern under cyclic thermo-mechanical loading

    NASA Astrophysics Data System (ADS)

    König, Diethard; Mahmoudi, Elham; Khaledi, Kavan; von Blumenthal, Achim; Schanz, Tom

    2016-04-01

    The excess electricity produced by renewable energy sources available during off-peak periods of consumption can be used e.g. to produce and compress hydrogen or to compress air. Afterwards the pressurized gas is stored in the rock salt cavities. During this process, thermo-mechanical cyclic loading is applied to the rock salt surrounding the cavern. Compared to the operation of conventional storage caverns in rock salt the frequencies of filling and discharging cycles and therefore the thermo-mechanical loading cycles are much higher, e.g. daily or weekly compared to seasonally or yearly. The stress strain behavior of rock salt as well as the deformation behavior and the stability of caverns in rock salt under such loading conditions are unknown. To overcome this, existing experimental studies have to be supplemented by exploring the behavior of rock salt under combined thermo-mechanical cyclic loading. Existing constitutive relations have to be extended to cover degradation of rock salt under thermo-mechanical cyclic loading. At least the complex system of a cavern in rock salt under these loading conditions has to be analyzed by numerical modeling taking into account the uncertainties due to limited access in large depth to investigate material composition and properties. An interactive evolution concept is presented to link the different components of such a study - experimental modeling, constitutive modeling and numerical modeling. A triaxial experimental setup is designed to characterize the cyclic thermo-mechanical behavior of rock salt. The imposed boundary conditions in the experimental setup are assumed to be similar to the stress state obtained from a full-scale numerical simulation. The computational model relies primarily on the governing constitutive model for predicting the behavior of rock salt cavity. Hence, a sophisticated elasto-viscoplastic creep constitutive model is developed to take into account the dilatancy and damage progress, as well as

  19. Survey on the management of orbital and intraocular tumors among oculofacial surgeons in the Asia-Pacific region.

    PubMed

    Wang, Priscilla Xinhui; Koh, Victor Teck Chang; Lun, Katherine; Sundar, Gangadhara

    2014-06-01

    A web-based anonymous survey was performed to assess the common practices of oculofacial surgeons in the management of orbital and intraocular tumors in the Asia-Pacific region. The questionnaire comprised a series of questions covering controversial topics sent via email to 131 oculofacial surgeons across 14 countries in the Asia-Pacific region. A total response rate of 61.7 % was achieved from May to December 2012. The most common benign orbital tumor was cavernous hemangioma (39.6 %) and the most common malignant orbital tumor was lymphoma (85.7 %). 40 % of surgeons recommended orbital radiation, for which the most common indications were thyroid eye disease (70.0 %) and malignancy (30.0 %). The most common orbitotomy approach was lateral (79.2 %). Most surgeons (87.1 %) offered enucleation for retinoblastoma, but there was also a significant proportion that offered chemoreduction with transpupillary thermotherapy or cryotherapy (58.1 %). Fewer surgeons offered brachytherapy (16.1 %) and intra-arterial chemotherapy (6.5 %). When performing enucleation for retinoblastoma, 81.8 % of surgeons performed a primary orbital implant placement. The most preferred type of implant was silicone/acrylic (90.2, 90.2 and 87.8 % for elderly, adults and children, respectively). The majority of surgeons used donor sclera (57.5 %) or no wrapping material at all (32.5 %). Almost all surgeons (95.1 %) did not drill and peg the implant for motility. We report the results of the first survey of oculofacial surgeons in the Asia-Pacific region on the management of intraocular and orbital tumors. In comparison with previous surveys performed in the USA and the UK, we found the practice patterns of the Asia-Pacific surgeons to be comparable.

  20. Anatomy of the human orbital muscle (OM): Features of its detailed topography, syntopy and morphology.

    PubMed

    Wilden, Andre; Feiser, Janna; Wöhler, Aliona; Isik, Zeynep; Bendella, Habib; Angelov, Doychin N

    2017-05-01

    The human orbital muscle (OM) is not readily accessible during ordinary anatomical teaching because of insufficient time and difficulties encountered in the preparation. Accordingly, its few anatomical descriptions are supported only by drawings, but not by photographs. The aim of this study was to present OM in dissected anatomic specimens in more detail. Following microscope-assisted dissection, its location, syntopy and morphology were analyzed in 88 orbits of 51 cadavers. Together with the periorbital connective tissue OM filled the infraorbital fissure (IOF) and extended back to the cavernous sinus. As a new finding, we here report that in 34% of the orbits we observed OM-fibers, which proceeded from IOF caudally to the facies infratemporalis of the maxilla. OM had a mean width of 4±1mm, a mean length of 22±5mm and its mean mass was 0.22±0.19g. The subsequent histological analysis of all specimens showed features of smooth muscle tissue: long, spindle-like cells with a centrally located cell nucleus (hematoxylin-eosin staining) which were innervated by tyrosine-hydroxylase immunopositive adrenergic fibers. We conclude that precise knowledge on OM might be very helpful not only to students in medicine and dentistry during anatomical dissection courses, but also to head and neck surgeons, ear-nose-throat specialists and neurosurgeons working in this field. Copyright © 2017 Elsevier GmbH. All rights reserved.

  1. A new strategic neurosurgical planning tool for brainstem cavernous malformations using interactive computer graphics with multimodal fusion images.

    PubMed

    Kin, Taichi; Nakatomi, Hirofumi; Shojima, Masaaki; Tanaka, Minoru; Ino, Kenji; Mori, Harushi; Kunimatsu, Akira; Oyama, Hiroshi; Saito, Nobuhito

    2012-07-01

    In this study, the authors used preoperative simulation employing 3D computer graphics (interactive computer graphics) to fuse all imaging data for brainstem cavernous malformations. The authors evaluated whether interactive computer graphics or 2D imaging correlated better with the actual operative field, particularly in identifying a developmental venous anomaly (DVA). The study population consisted of 10 patients scheduled for surgical treatment of brainstem cavernous malformations. Data from preoperative imaging (MRI, CT, and 3D rotational angiography) were automatically fused using a normalized mutual information method, and then reconstructed by a hybrid method combining surface rendering and volume rendering methods. With surface rendering, multimodality and multithreshold techniques for 1 tissue were applied. The completed interactive computer graphics were used for simulation of surgical approaches and assumed surgical fields. Preoperative diagnostic rates for a DVA associated with brainstem cavernous malformation were compared between conventional 2D imaging and interactive computer graphics employing receiver operating characteristic (ROC) analysis. The time required for reconstruction of 3D images was 3-6 hours for interactive computer graphics. Observation in interactive mode required approximately 15 minutes. Detailed anatomical information for operative procedures, from the craniotomy to microsurgical operations, could be visualized and simulated three-dimensionally as 1 computer graphic using interactive computer graphics. Virtual surgical views were consistent with actual operative views. This technique was very useful for examining various surgical approaches. Mean (±SEM) area under the ROC curve for rate of DVA diagnosis was significantly better for interactive computer graphics (1.000±0.000) than for 2D imaging (0.766±0.091; p<0.001, Mann-Whitney U-test). The authors report a new method for automatic registration of preoperative imaging data

  2. Bilateral Cavernous Nerve Crush Injury in the Rat Model: A Comparative Review of Pharmacologic Interventions.

    PubMed

    Haney, Nora M; Nguyen, Hoang M T; Honda, Matthew; Abdel-Mageed, Asim B; Hellstrom, Wayne J G

    2018-04-01

    It is common for men to develop erectile dysfunction after radical prostatectomy. The anatomy of the rat allows the cavernous nerve (CN) to be identified, dissected, and injured in a controlled fashion. Therefore, bilateral CN injury (BCNI) in the rat model is routinely used to study post-prostatectomy erectile dysfunction. To compare and contrast the available literature on pharmacologic intervention after BCNI in the rat. A literature search was performed on PubMed for cavernous nerve and injury and erectile dysfunction and rat. Only articles with BCNI and pharmacologic intervention that could be grouped into categories of immune modulation, growth factor therapy, receptor kinase inhibition, phosphodiesterase type 5 inhibition, and anti-inflammatory and antifibrotic interventions were included. To assess outcomes of pharmaceutical intervention on erectile function recovery after BCNI in the rat model. The ratio of maximum intracavernous pressure to mean arterial pressure was the main outcome measure chosen for this analysis. All interventions improved erectile function recovery after BCNI based on the ratio of maximum intracavernous pressure to mean arterial pressure results. Additional end-point analysis examined the corpus cavernosa and/or the major pelvic ganglion and CN. There was extreme heterogeneity within the literature, making accurate comparisons between crush injury and therapeutic interventions difficult. BCNI in the rat is the accepted animal model used to study nerve-sparing post-prostatectomy erectile dysfunction. However, an important limitation is extreme variability. Efforts should be made to decrease this variability and increase the translational utility toward clinical trials in humans. Haney NM, Nguyen HMT, Honda M, et al. Bilateral Cavernous Nerve Crush Injury in the Rat Model: A Comparative Review of Pharmacologic Interventions. Sex Med Rev 2018;6:234-241. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier

  3. Microsurgical Resection of a Solitary Spinal Epidural Cavernous Angioma: 3-Dimensional Operative Video.

    PubMed

    Ceccato, Guilherme H W; Henning, Lucélio; Prado, Julyana L; Rassi, Marcio S; Borba, Luis A B

    2018-05-21

    Solitary spinal epidural cavernous angiomas are rare vascular malformations. Surgical excision is the treatment of choice, as these lesions tend to grow or bleed at some point. In this 3-dimensional, narrated video, we present the case of a 61-year-old male who presented with progressive pain in the right paravertebral region secondary to an epidural cavernous angioma located at the T6/T7 level. Under intraoperative neurophysiological monitoring, a laminectomy between T5 and T7 was performed. A reddish, well delimited, and highly vascularized epidural mass was identified and dissected from the adjacent dura and nerve root, and an en bloc total resection was achieved. The patient was discharged neurologically intact on postoperative day 4, presenting a remarkable improvement of his pain at 2-month follow-up. Total excision of these lesions is possible in most of cases, remaining the standard treatment, with minimum complications. All procedures were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All data related to patient identification were removed from this surgical video and manuscript, with no need of a written informed consent.

  4. Posttraumatic carotid cavernous fistula that presented as seizure and focal neurological deficits with symptom resolution after therapeutic coil embolization.

    PubMed

    Klevtsova, Ekaterina; Nguyen-Min, Caroline; Lalani, Tania; Carlan, Stephen James; Madruga, Mario

    2015-02-01

    A posttraumatic carotid cavernous fistula can remain unrecognized and ultimately present with symptoms characteristic for a middle cerebral artery stroke. Progressive neurologic deterioration can occur until the condition is diagnosed and treated. If unrecognized and untreated, permanent damage may result. A 46-year-old white man with the history of a motor vehicle crash 6 months prior presented with complaints of acute onset of expressive aphasia and seizure-like activity for 3 days. On presentation, the patient was noted to have moderate proptosis and chemosis of the left eye. Magnetic resonance imaging of the brain showed an arteriovenous fistula arising from the anterolateral precavernous left internal carotid artery. This was directly communicating with the adjacent cortical veins along the medial aspect of the left temporal lobe, resulting in venous congestion in the left frontal opercular region, the left insula, and subinsular tracks. The patient underwent an intracranial coil embolization of a left carotid cavernous fistula. No complications were encountered, and the patient had near-complete resolution of neurologic deficits and left eye proptosis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although posttraumatic carotid cavernous fistula is a rare condition, it is important to be aware of this entity because immediate diagnosis and treatment may improve outcome. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Intracranial cavernous angioma: a practical review of clinical and biological aspects.

    PubMed

    Raychaudhuri, Ratul; Batjer, H Huntington; Awad, Issam A

    2005-04-01

    Cavernomas are an uncommon lesion seen in neurosurgical practice that can occasionally rupture. Recent developments in neurosurgical technique and microbiology have brought greater insight into the treatment and molecular pathogenesis of cavernoma. In this review, a historical overview of cavernous angioma, a current paradigm for treatment, promising new molecular biological developments, and suggestions for future directions in neurosurgical research are presented, with emphasis on practical clinical applications. A survey of the literature on cavernous angioma and consultation with the Department of Neurosurgery at Northwestern Memorial Hospital was conducted by the authors to gain greater insight regarding this lesion. Papers and consultation revealed the importance of careful evaluation of this lesion, new techniques such as functional magnetic resonance imaging and frameless stereotaxy that simplify clinical management of cavernomas, and potential mechanisms by which to tackle this lesion in the future. New basic knowledge on disease biology is summarized with practical applications in the clinical arena. There appear to be a number of controversies regarding management of this lesion. These include risk factors faced by the patient, controversy over the importance of resection, and modality through which the treatment should occur. An algorithm is presented to aid the neurosurgeon in management of these lesions. Exciting developments in neurosurgery and molecular biology will continue to have a major impact on clinical treatment of this disease. Unresolved issues regarding the importance of certain risk factors, the role for radiotherapy in treatments, and the underlying molecular abnormalities must be tackled to gain greater clarity in treatment of this lesion.

  6. Orbital complications associated with paranasal sinus infections - A 10-year experience in Israel.

    PubMed

    Segal, Nili; Nissani, Roni; Kordeluk, Sofia; Holcberg, Meni; Hertz, Shay; Kassem, Firas; Mansour, Anwar; Segal, Avichai; Gluck, Ofer; Roth, Yehudah; Honigman, Tal; Ephros, Moshe; Cohen Kerem, Ranan

    2016-07-01

    Orbital involvement is the most common complication of sinus infections. The epidemiology of the disease is continuously changing in the antibiotic era. Data on patients who were hospitalized due to acute sinusitis and orbital complications were retrospectively collected and analyzed from four medical centers in Israel during the years 2002-2012. 288 patients were included in the study, the average age was 14.4 years, 180 were males, and 220 were children. No significant annual increase in the number of patients was noted. The lowest number of patients was found during the summer 19.4%. A linear direct correlation was found between older age and prolonged hospital stay. Children were presented with a significantly higher Chandler score than adults. No patient had cavernous sinus thrombosis. 101 (35%) patients received antibiotics before hospital admission. Their average hospital stay was similar to those who were not treated prior to admission. 106 patients (39.8%) had fever. A direct correlation was found between older age and the presence of fever. 102 (35.4%) patients had leukocytosis. The difference in white blood cell count between patients younger than two years of age to the other groups was statistically significant. Forty four (15.3%) patients underwent surgical intervention. A direct correlation was found between leukocytosis and older age to surgery. Periorbital cellulitis occurs mainly in children and males and is less frequent in the summer. Children tend to have worse orbital involvement with lower temperatures than adults. Older age and leukocytosis are associated with surgical intervention. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. [Bilateral spontaneous carotid-cavernous fistula revealing Ehler-Danlos disease].

    PubMed

    Girardin, M; Puzenat, E; Humbert, P; Aubin, F

    2013-04-01

    A 34-year-old woman with an extensive surgical history developed two spontaneous carotido-cavernous fistula bilaterally. Skin examination revealed an acrogeric form of vascular Ehlers-Danlos syndrome and this diagnosis was confirmed by genetic analysis. Vascular Ehlers-Danlos syndrome is a rare autosomal dominant genetic disease that may be suspected on the grounds of clinical symptoms. Severe complications can occur in early life and are associated with a high mortality rate. The prognosis of vascular Ehlers-Danlos syndrome has been radically changed by the use of beta-blockers. The originality of our observation lies in the long time to onset of the initial complications in the absence of any problems during the numerous operations undergone by the patient, as well as the two childbirths. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. The Effect of Audio Tours on Learning and Social Interaction: An Evaluation at Carlsbad Caverns National Park

    ERIC Educational Resources Information Center

    Novey, Levi T.; Hall, Troy E.

    2007-01-01

    Auditory forms of nonpersonal communication have rarely been evaluated in informal settings like parks and museums. This study evaluated the effect of an interpretive audio tour on visitor knowledge and social behavior at Carlsbad Caverns National Park. A cross-sectional pretest/posttest quasi-experimental design compared the responses of audio…

  9. Transient pituitary enlargement with central hypogonadism secondary to bilateral cavernous sinus thrombosis: pituitary oedema?

    PubMed

    Joubert, Michael; Verdon, Renaud; Reznik, Yves

    2009-05-01

    Design We report the case of an incidental pituitary mass discovered in the context of bilateral cavernous sinus thrombosis due to a bacterial pansinusitis. Conclusions Magnetic resonance imaging features of the pituitary lesion, together with transient central hypogonadism and total regression of the mass after anticoagulation and antimicrobial therapy, suggest that this lesion is a pituitary oedema of vascular mechanism. Other possible causes of pituitary mass in such a situation are also discussed.

  10. Endovascular embolization of carotid-cavernous fistulas: A pioneering experience in Peru

    PubMed Central

    Plasencia, Andres R.; Santillan, Alejandro

    2012-01-01

    Background: Endovascular embolization represents the method of choice for the treatment of carotid-cavernous fistulas (CCFs). Methods: We report our experience using the endovascular technique in 24 patients harboring 25 CCFs treated between October 1994 and April 2010, with an emphasis on the role of detachable balloons for the treatment of direct CCFs. Results: Of the 16 patients who presented with direct CCFs (Barrow Type A CCFs) (age range, 7–62 years; mean age, 34.3 years), 14 were caused by traumatic injury and 2 by a ruptured internal carotid artery (ICA) aneurysm. Eight patients (age range, 32–71 years; mean age, 46.5 years) presented with nine indirect CCFs (Barrow Types B, C, and D). The clinical follow-up after endovascular treatment ranged from 2 to 108 months (mean, 35.2 months). In two cases (8%), the endovascular approach failed. Symptomatic complications related to the procedure occurred in three patients (12.5%): transient cranial nerve palsy in two patients and a permanent neurological deficit in one patient. Detachable balloons were used in 13 out of 16 (81.3%) direct CCFs and were associated with a cure rate of 92.3%. Overall, the angiographic cure rate was obtained in 22 out of 25 (88%) fistulas. Patients presenting with III nerve palsy improved gradually between 1 day and 6 months after treatment. Good clinical outcomes [modified Rankin scale (mRS) ≤ 2] were observed in 22 out of 24 (91.6%) patients at last follow-up. Conclusions: Endovascular treatment using detachable balloons still constitutes a safe and effective method to treat direct carotid-cavernous fistulas. PMID:22363900

  11. Indirect carotid cavernous fistula mimicking ocular myasthenia.

    PubMed

    Leishangthem, Lakshmi; Satti, Sudhakar Reddy

    2017-10-19

    71-year-old woman with progressive left-sided, monocular diplopia and ptosis. Her symptoms mimicked ocular myasthenia, but she had an indirect carotid cavernous fistula (CCF). She was diagnosed with monocular myasthenia gravis (negative acetylcholinesterase antibody) after a positive ice test and started on Mestinon and underwent a thymectomy complicated by a brachial plexus injury. Months later, she developed left-sided proptosis and ocular bruit. She was urgently referred to neuro-interventional surgery and was diagnosed with an indirect high-flow left CCF, which was treated with Onyx liquid and platinum coil embolisation. Mestinon was discontinued. Her ophthalmic symptoms resolved. However, she was left with a residual left arm and hand hemiparesis and dysmetria secondary to a brachial plexus injury. Indirect CCF usually can present with subtle and progressive symptoms leading to delayed diagnosis or misdiagnosis. It is important for ophthalmologists to consider this differential in a patient with progressive ocular symptoms. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Spontaneous Carotid-Cavernous Fistula in the Type IV Ehlers-Danlos Syndrome.

    PubMed

    Kim, Jeong Gyun; Cho, Won-Sang; Kang, Hyun-Seung; Kim, Jeong Eun

    2014-02-01

    Ehlers-Danlos syndrome (EDS) is a rare inherited connective disease. Among several subgroups, type IV EDS is frequently associated with spontaneous catastrophic bleeding from a vascular fragility. We report on a case of carotid-cavernous fistula (CCF) in a patient with type IV EDS. A 46-year-old female presented with an ophthalmoplegia and chemosis in the right eye. Subsequently, seizure and cerebral infarction with micro-bleeds occurred. CCF was completely occluded with transvenous coil embolization without complications. Thereafter, the patient was completely recovered. Transvenous coil embolization can be a good treatment of choice for spontaneous CCF with type IV EDS. However, every caution should be kept during invasive procedure.

  13. Comparative analysis of use of porous orbital implant with mucus membrane graft and dermis fat graft as a primary procedure in reconstruction of severely contracted socket

    PubMed Central

    Bhattacharjee, Kasturi; Bhattacharjee, Harsha; Kuri, Ganesh; Das, Jayanta Kr; Dey, Debleena

    2014-01-01

    Purpose: The purpose of our study is to present a surgical technique of primary porous orbital ball implantation with overlying mucus membrane graft (MMG) for reconstruction of severely contracted socket and to evaluate prosthesis retention and motility in comparison to dermis fat graft (DFG). Study Design: Prospective comparative study. Materials and Methods: A total of 24 patients of severe socket contracture (Grade 2-4 Krishna's classification) were subdivided into two groups, 12 patients in each group. In Group I, DFG have been used for reconstruction. In Group II, porous polyethylene implant with MMG has been used as a primary procedure for socket reconstruction. In Group I DFG was carried out in usual procedure. In case of Group II, vascularized scar tissues were separated 360° and were fashioned into four strips. A scleral capped porous polyethylene implant was placed in the intraconal space and four strips of scar tissue were secured to the scleral cap and extended part overlapped the implant to make a twofold barrier between the implant and MMG. Patients were followed-up as per prefixed proforma. Prosthesis motility and retention between the two groups were measured. Results: In Group I, four patients had recurrence of contracture with fall out of prosthesis. In Group II stable reconstruction was achieved in all the patients. In terms of prosthesis motility, maximum in Group I was 39.2% and Group II, was 59.3%. The difference in prosthesis retention (P = 0.001) and motility (P = 0.004) between the two groups was significant. Conclusion: Primary socket reconstruction with porous orbital implant and MMG for severe socket contracture is an effective method in terms of prosthesis motility and prosthesis retention. PMID:24618485

  14. Fatal Peritoneal Bleeding Following Embolization of a Carotid-Cavernous Fistula in Ehlers-Danlos Syndrome Type IV

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

    Usinskiene, Jurgita; Mazighi, Mikael; Bisdorff, Annouk

    2006-12-15

    We report the case of a 25-year-old woman treated for a spontaneous carotid-cavernous fistula in a context of Ehlers-Danlos syndrome type IV. Embolization with a transvenous approach was achieved without complications; however, the patient died 72 hr later of massive intraperitoneal bleeding. At autopsy, no lesion of the digestive arteries was identified. Possible causes of this bleeding are discussed.

  15. Cerebral cavernous malformations: natural history and clinical management.

    PubMed

    Gross, Bradley A; Du, Rose

    2015-01-01

    Cavernous malformations (CMs) are angiographically-occult clusters of dilated sinusoidal channels that may present clinically with seizures, focal neurological deficits and/or hemorrhage. Across natural history studies, the annual hemorrhage rate ranged from 1.6-3.1% per patient-year, decreasing to 0.08-0.2% per patient-year for incidental CMs and to 0.3-0.6% for the collective group of unruptured CMs. Prior hemorrhage is a significant risk factor for subsequent CM hemorrhage. Hemorrhage clustering, particularly within the first 2 years, is an established phenomenon that may confound results of natural history studies evaluating the rate of rehemorrhage. Indeed, rehemorrhage rates for hemorrhagic CMs range from 4.5-22.9% in the literature. Surgical resection is the gold standard treatment for surgically-accessible, symptomatic CMs. Incidental CMs or minimally symptomatic, surgically inaccessible eloquent lesions may be considered for observation. Stereotactic radiosurgery is a controversial treatment approach of consideration only for cases of highly aggressive, surgically inaccessible CMs.

  16. Decrease in neuronal nicotinic acetylcholine receptor subunit and PSD-93 transcript levels in the male mouse MPG after cavernous nerve injury or explant culture.

    PubMed

    Girard, Beatrice M; Merriam, Laura A; Tompkins, John D; Vizzard, Margaret A; Parsons, Rodney L

    2013-11-15

    Quantitative real-time PCR was used to test whether cavernous nerve injury leads to a decrease in major pelvic ganglia (MPG) neuronal nicotinic ACh receptor (nAChR) subunit and postsynaptic density (PSD)-93 transcript levels. Subunits α3, β4, and α7, commonly expressed in the MPG, were selected for analysis. After 72 h in explant culture, MPG transcript levels for α3, β4, α7, and PSD-93 were significantly depressed. Three days after cavernous nerve axotomy or crush in vivo, transcript levels for α3, β4, and PSD-93, but not for α7, were significantly depressed. Three days after dissection of the cavernous nerve free of underlying tissue and application of a 5-mm lateral stretch (manipulation), transcript levels for α3 and PSD-93 were also significantly decreased. Seven days after all three surgical procedures, α3 transcript levels remained depressed, but PSD-93 transcript levels were still decreased only after axotomy or nerve crush. At 30 days postsurgery, transcript levels for the nAChR subunits and PSD-93 had recovered. ACh-induced currents were significantly smaller in MPG neurons dissociated from 3-day explant cultured ganglia than from those recorded in neurons dissociated from acutely isolated ganglia; this observation provides direct evidence showing that a decrease in nAChR function was coincident with a decrease in nAChR subunit transcript levels. We conclude that a downregulation of nAChR subunit and PSD-93 expression after cavernous nerve injury, or even manipulation, could interrupt synaptic transmission within the MPG and thus contribute to the loss of neural control of urogenital organs after pelvic surgeries.

  17. Long-term high-fat consumption leads to downregulation of Akt phosphorylation of eNOS at Ser1177 and upregulation of Sirtuin-1 expression in rat cavernous tissue.

    PubMed

    Tomada, I; Negrão, R; Almeida, H; Neves, D

    2014-04-01

    Long-term consumption of high-fat diets negatively interferes with metabolic status and promotes endothelial dysfunction and inflammation. In the cavernous tissue, these outcomes become conspicuous in the elderly and strongly affect penile erection, a vascular process highly dependent on local nitric oxide bioavailability. Although epidemiological data links erectile dysfunction to nutritional patterns, the underlying molecular mechanisms remain unclear. Therefore, we investigated the effects of long-term high-fat diet on endothelial nitric oxide synthase (eNOS)-Sirtuin-1 axis and Akt/eNOS phosphorylation in the cavernous tissue of Sprague-Dawley rats, and compared with energy-restricted animals. We demonstrated that high-fat diet intake led to a noteworthy decrease in eNOS phosphorylation at Ser1177 residue through the Akt pathway, which seems to be compensated by upregulation of phosphorylation at Ser615, but without an increment in nitric oxide production. These results are accompanied by an increase of systemic inflammatory markers and upregulation of the inducible NOS and of the deacetylase Sirtuin-1 in the cavernous tissue to levels apparently detrimental to cells and to metabolic homeostasis. Conversely, in long-term energy-restricted animals, the rate of phosphorylation of eNOS at Ser1177 diminished, but the activation of the enzyme increased through phosphorylation of eNOS at Ser615, resulting in an enhancement in nitric oxide bioavailability. Taken together, our results demonstrate that long-term nutritional conditions override the influence of age on the eNOS expression and activation in rat cavernous tissue.

  18. Spontaneous Carotid-Cavernous Fistula in the Type IV Ehlers-Danlos Syndrome

    PubMed Central

    Kim, Jeong Gyun; Cho, Won-Sang; Kim, Jeong Eun

    2014-01-01

    Ehlers-Danlos syndrome (EDS) is a rare inherited connective disease. Among several subgroups, type IV EDS is frequently associated with spontaneous catastrophic bleeding from a vascular fragility. We report on a case of carotid-cavernous fistula (CCF) in a patient with type IV EDS. A 46-year-old female presented with an ophthalmoplegia and chemosis in the right eye. Subsequently, seizure and cerebral infarction with micro-bleeds occurred. CCF was completely occluded with transvenous coil embolization without complications. Thereafter, the patient was completely recovered. Transvenous coil embolization can be a good treatment of choice for spontaneous CCF with type IV EDS. However, every caution should be kept during invasive procedure. PMID:24653803

  19. Occipital Neuralgia from C2 Cavernous Malformation

    PubMed Central

    Ha, Sang-woo; Choi, Jin-gyu; Son, Byung-chul

    2018-01-01

    A unique case is presented of chronic occipital neuralgia (ON) caused by cavernous malformation (CM) in the intramedullary C2 spinal cord and subsequent pain relief and remodeling of allodynic pain following dorsal root rhizotomy. A 53-year-old male presented with a 30-year history of chronic allodynic, paroxysmal lancinating pain in the greater and lesser occipital nerves. Typically, the pain was aggravated with neck extension and head movement. Magnetic resonance imaging showed a CM in the right posterolateral side of the intramedullary C2 cord. Considering potential risks associated with removal of the lesion, intradural C1-3 dorsal root rhizotomy with dentate ligament resection was performed. The paroxysmal lancinating pain of ON was significantly alleviated, and the remodeling of the extent of allodynic pain was noted after C1-3 dorsal root rhizotomy. These changes gradually occurred during the second postoperative month, and this effect was maintained for 24 months postoperatively. Significant reduction in chronic allodynic pain of secondary ON caused by cervicomedullary CM involving central sensitization in the trigeminocervical complex was observed with reduction of irritating, afferent input with C1-C3 dorsal root rhizotomy. PMID:29682056

  20. Occipital Neuralgia from C2 Cavernous Malformation.

    PubMed

    Ha, Sang-Woo; Choi, Jin-Gyu; Son, Byung-Chul

    2018-01-01

    A unique case is presented of chronic occipital neuralgia (ON) caused by cavernous malformation (CM) in the intramedullary C2 spinal cord and subsequent pain relief and remodeling of allodynic pain following dorsal root rhizotomy. A 53-year-old male presented with a 30-year history of chronic allodynic, paroxysmal lancinating pain in the greater and lesser occipital nerves. Typically, the pain was aggravated with neck extension and head movement. Magnetic resonance imaging showed a CM in the right posterolateral side of the intramedullary C2 cord. Considering potential risks associated with removal of the lesion, intradural C1-3 dorsal root rhizotomy with dentate ligament resection was performed. The paroxysmal lancinating pain of ON was significantly alleviated, and the remodeling of the extent of allodynic pain was noted after C1-3 dorsal root rhizotomy. These changes gradually occurred during the second postoperative month, and this effect was maintained for 24 months postoperatively. Significant reduction in chronic allodynic pain of secondary ON caused by cervicomedullary CM involving central sensitization in the trigeminocervical complex was observed with reduction of irritating, afferent input with C1-C3 dorsal root rhizotomy.

  1. Cavernous sinus syndrome due to osteochondromatosis in a cat.

    PubMed

    Perazzi, Anna; Bernardini, Marco; Mandara, Maria T; De Benedictis, Giulia M; De Strobel, Francesca; Zotti, Alessandro

    2013-12-01

    A 1-year-old sexually intact male Korat cat was referred for ophthalmological consultation due to anisocoria. Mydriasis with external ophthalmoplegia and absence of pupillary light responses in the right eye and nasofacial hypalgesia were seen. Cavernous sinus syndrome (CSS) was suspected. Bilateral deformities of the jaw and phalangeal bones, severe spinal pain and abnormal conformation of the lumbar spine were also present. Radiographic examination revealed several mineralised masses in the appendicular and axial skeleton, indicative of multiple cartilaginous exostoses. For further investigation of the CSS-related neurological deficits, the cat underwent computed tomography (CT) examination of the skull. CT images revealed a non-vascularised, calcified, amorphous mass originating from the right lateral skull base and superimposing on the sella turcica. Based on the severity of diffuse lesions and owing to the clinical signs of extreme pain, the cat was euthanased. A diffuse skeletal and intracranial osteochondromatosis was diagnosed histologically.

  2. Fractionated Stereotactic Radiotherapy Treatment of Cavernous Sinus Meningiomas: A Study of 100 Cases

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

    Litre, Claude Fabien; Colin, Philippe; Noudel, Remy

    Purpose: We discuss our experiences with fractionated stereotactic radiotherapy (FSR) in the treatment of cavernous sinus meningiomas. Methods and Materials: From 1995 to 2006, we monitored 100 patients diagnosed with cavernous sinus meningiomas; 84 female and 16 male patients were included. The mean patient age was 56 years. The most common symptoms were a reduction in visual acuity (57%), diplopia (50%), exophthalmy (30%), and trigeminal neuralgia (34%). Surgery was initially performed on 26 patients. All patients were treated with FSR. A total of 45 Gy was administered to the lesion, with 5 fractions of 1.8 Gy completed each week. Patientmore » treatment was performed using a Varian Clinac linear accelerator used for cranial treatments and a micro-multileaf collimator. Results: No side effects were reported. Mean follow-up period was 33 months, with 20% of patients undergoing follow-up evaluation of more than 4 years later. The tumor control rate at 3 years was 94%. Three patients required microsurgical intervention because FSR proved ineffective. In terms of functional symptoms, an 81% improvement was observed in patients suffering from exophthalmy, with 46% of these patients being restored to full health. A 52% improvement was observed in diplopia, together with a 67% improvement in visual acuity and a 50% improvement in type V neuropathy. Conclusions: FSR facilitates tumor control, either as an initial treatment option or in combination with microsurgery. In addition to being a safe procedure with few side effects, FSR offers the significant benefit of superior functional outcomes.« less

  3. Pathological Evaluation of Radiation-Induced Vascular Lesions of the Brain: Distinct from De Novo Cavernous Hemangioma

    PubMed Central

    Cha, Yoon Jin; Nahm, Ji Hae; Ko, Ji Eun; Shin, Hyun Joo; Chang, Jong-Hee; Cho, Nam Hoon

    2015-01-01

    Purpose We aimed to evaluate the histologic and radiologic findings of vascular lesions after stereotactic radiosurgery (SRS) categorized as radiation-induced cavernous hemangioma (RICH). Materials and Methods Among 89 patients who underwent neurosurgery for cavernous hemangioma, eight RICHs from 7 patients and 10 de novo CHs from 10 patients were selected for histopathological and radiological comparison. Results Histologically, RICHs showed hematoma-like gross appearance. Microscopically, RICH exhibited a hematoma-like area accompanied by proliferation of thin-walled vasculature with fibrin deposits and infiltrating foamy macrophages. In contrast, CHs demonstrated localized malformed vasculature containing fresh and old clotted blood on gross examination. Typically, CHs consisted of thick, ectatic hyalinized vessels lined by endothelium under a light microscope. Magnetic resonance imaging of RICHs revealed some overlapping but distinct features with CHs, including enhancing cystic and solid components with absence or incomplete popcorn-like appearance and partial hemosiderin rims. Conclusion Together with histologic and radiologic findings, RICH may result from blood-filled space after tissue destruction by SRS, accompanied with radiation-induced reactive changes rather than vascular malformation. Thus, the term "RICH" would be inappropriate, because it is more likely to be an inactive organizing hematoma rather than proliferation of malformed vasculature. PMID:26446658

  4. Multidisciplinary management of an intra-sellar cavernous hemangioma: Case report and review of the literature.

    PubMed

    Chibbaro, S; Cebula, H; Ganau, M; Gubian, A; Todeschi, J; Lhermitte, B; Proust, F; Noel, G

    2018-06-01

    Extra-axial cavernous hemangiomas (ECH) are rare vascular lesions with a tendency to grow within the medial structures of the middle cranial fossa. This pathological entity lacks specific symptoms, and falls into the category of differential diagnosis of space occupying lesions in the cavernous sinus (CS) with or without sellar involvement, including those of tumoral, vascular and inflammatory nature. Of note, ECH can also be indolent, and is at times discovered incidentally during autopsy investigations. On radiological studies, ECH with sellar extension are frequently mistaken at first for pituitary adenomas. Total removal of intrasellar-CS ECH is technically demanding and burdened by remarkable morbidity and mortality rates, mostly related to the complex neuroanatomy of the CS-sellar region (i.e., peri and postoperative bleeding, and transitory or permanent nerve palsies, hormonal deficits). Consequently, only a few cases of successful total removal have been reported so far in the literature. Surgical debulking with cranial nerve decompression followed by stereotactic radiosurgery is currently considered the best alternative to total removal when the latter carries excessive perioperative risks. We present a rare case of a mainly located intrasellar ECH extending to the left CS discussing its clinical features and focusing on the most relevant aspects of the surgical management along with a review of the pertinent literature. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Pediatric Pontine Cavernous Malformations: The Presigmoid, Posterior Petrosal Approach.

    PubMed

    Kulwin, Charles G; Payner, Troy D; Nelson, Rick F; Ackerman, Laurie L; Fulkerson, Daniel H

    2018-03-03

    Brainstem cavernous malformations (cavernomas) in children have a high risk of hemorrhage and neurological deterioration. This risk is magnified if the child has a genetic predisposition for cavernoma formation. The surgical management is challenging and carries a significant risk of morbidity. To describe the feasibility of a posterior petrosal approach to brainstem cavernomas in a pediatric population. A single institution operative experience with this technique was reviewed; 2 cases were identified and are technically described here with supportive figures and illustrations, as well as a focused literature review. Two pediatric cases with multiple symptomatic hemorrhages from large expanding pontine cavernomas were identified. Both cavernomas were resected through a presigmoid posterior petrosal approach. While this approach is well described in the adult literature for ventral brainstem lesions, its description for the treatment of pontine cavernomas in the pediatric populations is scarce. This study demonstrates the utility and feasibility of the posterior petrosal approach in two pediatric patients at different points in cranial base development.

  6. Modeling of coupled thermodynamic and geomechanical performance of underground compressed air energy storage in lined rock caverns

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

    Rutqvist, Jonny; Kim, Hyung-Mok; Ryu, Dong-Woo

    We applied coupled nonisothermal, multiphase fluid flow and geomechanical numerical modeling to study the coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in concrete-lined rock caverns. The paper focuses on CAES in lined caverns at relatively shallow depth (e.g., 100 m depth) in which a typical CAES operational pressure of 5 to 8 MPa is significantly higher than both ambient fluid pressure and in situ stress. We simulated a storage operation that included cyclic compression and decompression of air in the cavern, and investigated how pressure, temperature and stress evolve over several months of operation. Wemore » analyzed two different lining options, both with a 50 cm thick low permeability concrete lining, but in one case with an internal synthetic seal such as steel or rubber. For our simulated CAES system, the thermodynamic analysis showed that 96.7% of the energy injected during compression could be recovered during subsequent decompression, while 3.3% of the energy was lost by heat conduction to the surrounding media. Our geomechanical analysis showed that tensile effective stresses as high as 8 MPa could develop in the lining as a result of the air pressure exerted on the inner surface of the lining, whereas thermal stresses were relatively smaller and compressive. With the option of an internal synthetic seal, the maximum effective tensile stress was reduced from 8 to 5 MPa, but was still in substantial tension. We performed one simulation in which the tensile tangential stresses resulted in radial cracks and air leakage though the lining. This air leakage, however, was minor (about 0.16% of the air mass loss from one daily compression) in terms of CAES operational efficiency, and did not significantly impact the overall energy balance of the system. However, despite being minor in terms of energy balance, the air leakage resulted in a distinct pressure increase in the surrounding rock that could

  7. CNS cavernous haemangioma: "popcorn" in the brain and spinal cord.

    PubMed

    Hegde, A N; Mohan, S; Lim, C C T

    2012-04-01

    Cavernous haemangiomas (CH) are relatively uncommon non-shunting vascular malformations of the central nervous system and can present with seizures or with neurological deficits due to haemorrhage. Radiologists can often suggest the diagnosis of CH based on characteristic magnetic resonance imaging (MRI) features, thus avoiding further invasive procedures such as digital subtraction angiography or surgical biopsy. Although typical MRI appearance combined with the presence of multiple focal low signal lesions on T2*-weighted images or the presence of one or more developmental venous anomaly within the brain can improve the diagnostic confidence, serial imaging studies are often required if a solitary CH presents at a time when the imaging appearances had not yet matured to the typical "popcorn" appearance. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  8. Purely neuroendoscopic resection of an intraventricular cavernous angioma: case report.

    PubMed

    Giannetti, Alexandre Varella

    2013-01-01

    Intraventricular cavernomas are rare and generally treated by microsurgical approach. With the advances in neuroendoscopy, intraventricular lesions have been managed by this technique. However, tumor size and vascular nature are considered restrictive factors. As far as we are concerned, there are two cases in the literature of intraventricular cavernoma resection done by neuroendoscopy. We describe a case of a man who presented with hydrocephalus secondary to a mesencephalic cavernoma and a second cavernous angioma located at the dorsum thalamus. This second lesion was successfully removed using a pure neuroendoscopic technique at the same time as a third ventriculostomy was performed. As neuroendoscopy evolves, we see that lesions considered impossible to be managed by neuroendoscopy before today are being treated with the advantages that the minimally invasive surgery offers. Georg Thieme Verlag KG Stuttgart · New York.

  9. Management of posttraumatic enophthalmos.

    PubMed

    Chen, Chien-Tzung; Huang, Faye; Chen, Yu-Ray

    2006-01-01

    Posttraumatic enophthalmos is one of the common sequelae that appears after facial injury and remains a challenge to treat for craniomaxillofacial surgeons. Several theories have been advocated regarding enophthalmos; however, the most well accepted concept is the enlargement of the orbital cavity after displacement due to orbital fractures. Generally, a 1 cm3 increase in orbital volume causes 0.8 mm of enophthalmos. Thorough knowledge of the orbital anatomy is fundamental and critical for the successful surgical correction of enophthalmos because most treatment failures are due to inadequate orbital dissection from fear of injuring the optic nerve and globe. A complete preoperative plan should be built on a comprehensive clinical examination of the periorbital soft tissue and bony components, detailed ophthalmic examination, and high resolution computed tomography scans in the axial, coronal and reformatted sagittal planes. Based on the anatomic deformities, there are two major fracture types including orbital blow out fractures and zygomatico-orbital fractures, resulting in posttraumatic enophthalmos. Treatment modalities and methods of approach are adapted according to the severity of the orbital deformities. Minor complications include ectropion, entropion, dystopia, diplopia, and residual enophthalmos. Rare but severe complications such as intraconal misplacement of the bone graft or retrobulbar hemorrhage with subsequent blindness may be encountered. The success of the procedures depend on adequate dissection and mobilization of the displaced soft tissue, correct repositioning of the dislocated or malunited bony orbit, and proper intra-orbital grafting.

  10. May the Inferior Petrosal Sinus Recanalization During Endovascular Treatment for Carotid-Cavernous Fistulas Increase the Risk of Sixth Nerve Palsy?

    PubMed

    Robert, Thomas; Valsecchi, Daniele; Sylvestre, Philippe; Blanc, Raphaël; Ciccio, Gabriele; Smajda, Stanislas; Redjem, Hocine; Piotin, Michel

    2018-05-03

    Sixth nerve palsy is a common complication of endovascular treatment for carotid-cavernous fistulas (CCF). Two hypotheses are evoked: the spontaneous venous congestion into the cavernous sinus and the direct compression of the nerve by the embolic agent into the cavernous sinus. Nevertheless, the evidence is still uncertain. Knowing the vicinity of the sixth nerve with the inferior petrosal sinus (IPS) in the Dorello canal, we hypothesized that the recanalization of the IPS increased the risk of nerve damage. We analyzed a prospective database of patients treated for CCFs from March 2009 to April 2016. We excluded patients who did not need treatment, cases of high-flow CCF, and patients lost to follow-up, obtaining a homogeneous population of 82 patients with indirect CCFs. This population was divided in 2 groups: patients without new-onset/worsening of sixth nerve palsy and patients with this postprocedural complication. Our main endpoints were the potential differences between patients with or without recanalization of IPS and between those who underwent or not an embolization with Onyx-18. We did not find any statistically meaningful difference between the 2 groups concerning the necessity of IPS recanalization (P > 0.999, odds ratio 0.97, 95% confidence interval 0.32-2.96) or with the use of Onyx-18 as an embolic agent (P = 0.56; odds ratio 1.41, 95% confidence interval 0.41-2.45). The recanalization of a thrombosed IPS does not increase the risk of procedural sixth nerve damage. The initial injury seems to relate with development/worsening of a sixth nerve palsy. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Improved penile histology by phalloidin stain: circular and longitudinal cavernous smooth muscles, dual-endothelium arteries, and erectile dysfunction-associated changes.

    PubMed

    Lin, Guiting; Qiu, Xuefeng; Fandel, Thomas M; Albersen, Maarten; Wang, Zhong; Lue, Tom F; Lin, Ching-Shwun

    2011-10-01

    To investigate whether fluorochrome-conjugated phalloidin can delineate cavernous smooth muscle (CSM) cells and whether it can be combined with immunofluorescence (IF) staining to quantify erectile dysfunction (ED)-associated changes. ED was induced by cavernous nerve crush in rats. Penile tissues of control and ED rats were stained with Alexa-488-conjugated phalloidin and/or with antibodies against rat endothelial cell antigen (RECA), CD31, neuronal nitric oxide synthase (nNOS), and collagen-IV (Col-IV). Phalloidin was able to delineate CSM as composed of a circular and a longitudinal compartment. When combined with IF stain for CD31 or RECA, it helped the identification of the helicine arteries as covered by endothelial cells on both sides of the smooth muscle layer. When combined with IF stain for nNOS, it helped the identification that nNOS-positive nerves were primarily localized within the dorsal nerves and in the adventitia of dorsal arteries. When combined with IF stain for Col-IV, it helped identify that Col-IV was localized around smooth muscles and beneath the endothelium. Phalloidin also facilitated the quantitative analysis of ED-related changes in the penis. In rats with cavernous nerve injury, RECA or Col-IV expression did not change significantly, but CSM and nNOS nerve contents decreased significantly. Phalloidin stain improved penile histology, enabling the visualization of the circular and longitudinal compartments in the CSM. It also worked synergistically with IF stain, permitting the visualization of the dual endothelial covering in helicine arteries, and facilitating the quantification of ED-related histologic changes. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Congenital tri-cavernous hemangiomas of the right buccal region, right accessory parotid gland, and masseter muscle region.

    PubMed

    Yang, Tao; Gu, Yongchun; Zhang, Li; Hua, Zequan

    2014-03-01

    We report a rare case of congenital tri-cavernous hemangiomas of the right buccal region, right accessory parotid gland, and masseter muscle region in an adult. The patient, a 25-year-old woman, complained of 3 masses in her right midcheek. Ultrasonographic and computed tomographic findings showed an irregular-shaped mass (multiple calcifications) with a well-defined margin in the masseter muscle region, an ellipse-shaped mass (multiple calcifications) with a well-defined margin in the right buccal region, and a comma-shaped mass (no calcifications) with a well-defined margin separate from the parotid gland in the right accessory parotid gland region. These iconographic findings suggested that the masses were all hemangiomas separately originating from the parotid gland, accessory parotid gland, and masseter muscle. The masses were completely removed through a standard parotid incision without postoperative facial palsy, skin deformity, and difficulty in secreting saliva. Findings from histologic examination of the tumor revealed multiple, thin-walled, and dilated blood vessels, confirming the diagnosis of cavernous hemangiomas. Ultrasonographic and computed tomographic findings were extremely useful in diagnosing the mass/masses as hemangioma before surgery, clarifying relationships between the mass and adjacent structures, and determining the surgical approach to the mass/masses.

  13. Feasibility of Using Intravascular Ultrasonography for Assessment of Giant Cavernous Aneurysm after Endovascular Treatment: A Technical Report

    PubMed Central

    Majidi, Shahram; Grigoryan, Mikayel; Tekle, Wondwossen G; Watanabe, Masaki; Qureshi, Adnan I

    2012-01-01

    Introduction Intravascular ultrasonography (IVUS) has been shown as a valuable adjunct imaging tool during endovascular procedures but its value in detection of any recurrence during follow up after endovascular coil embolization of large and giant intracranial aneurysms is not reported. Methods A 41 years old man who had been treated using stent assisted coil embolization for cavernous segment aneurysm of the left internal carotid artery underwent 60 month angiographic follow up. Concurrently, IVUS catheter was advanced under fluoroscopic guidance inside the cavernous portion of the left internal carotid artery. Then IVUS images were used to visualize the stent, coil loops, and aneurysm neck. Results The angiographic images were limited because of superimposition of the aneurysm on the parent vessel in all projections. IVUS images demonstrated that the stent was patent along its whole length and there was no sign of stent deformity or in-stent thrombosis. Loops of the coil were visualized as hyperechoic signals inside the aneurysm and there was no sign of herniated loops of coil inside the stent. Conclusion In this case report, we observed that adjunct use of IVUS can provide valuable information not ascertained by angiography during follow up assessment of coil embolized aneurysm. PMID:22737259

  14. The “Endothelialized Muscularis Mucosae”: A Case Report Describing a Large Cavernous Hemangioma at the Terminal Ileum and a New Histologic Clue for Preoperative Diagnosis from Endoscopic Biopsy

    PubMed Central

    Purdy-Payne, Erin K.; Miner, Jean F.; Foles, Brandon; Tran, Tien-Anh N.

    2015-01-01

    Cavernous hemangiomas of the gastrointestinal tract are quite rare and, until now, have been difficult to diagnose preoperatively due their nonspecific presentations and imaging features, as well as a lack of histologic description pertaining to small superficial biopsies such as those obtained endoscopically. We report a unique case of a 4 cm transmural cavernous hemangioma in the terminal ileum with literature review and describe a new histologic finding—the “endothelialized muscularis mucosae,” which was discovered upon review of the endoscopic biopsy and could potentially facilitate preoperative diagnosis of these lesions from endoscopic biopsies in the future. These lesions have classically required surgical resection in order to make a definitive diagnosis and rule out malignancy, with which they share many historical and radiographic features. Due to their potential to cause bowel obstruction, intussusception, perforation, and hemorrhage, these lesions may ultimately require surgical resection to relieve symptoms or prevent or treat complications—however, surgical planning and patient counseling could be greatly improved by a preoperative diagnosis. Therefore, gastroenterologists, pathologists, and surgeons should be aware of the “endothelialized muscularis mucosae” which can be very helpful in diagnosing GI cavernous hemangiomas from endoscopic biopsies. PMID:26442160

  15. A servo controlled gradient loading triaxial model test system for deep-buried cavern.

    PubMed

    Chen, Xu-guang; Zhang, Qiang-yong; Li, Shu-cai

    2015-10-01

    A servo controlled gradient loading model test system is developed to simulate the gradient geostress in deep-buried cavern. This system consists of the gradient loading apparatus, the digital servo control device, and the measurement system. Among them, the gradient loading apparatus is the main component which is used for exerting load onto the model. This loading apparatus is placed inside the counterforce wall/beam and is divided to several different loading zones, with each loading zone independently controlled. This design enables the gradient loading. Hence, the "real" geostress field surrounding the deep-buried cavern can be simulated. The loading or unloading process can be controlled by the human-computer interaction machines, i.e., the digital servo control system. It realizes the automation and visualization of model loading/unloading. In addition, this digital servo could control and regulate hydraulic loading instantaneously, which stabilizes the geostress onto the model over a long term. During the loading procedure, the collision between two adjacent loading platens is also eliminated by developing a guide frame. This collision phenomenon is induced by the volume shrinkage of the model when compressed in true 3D state. In addition, several accurate measurements, including the optical and grating-based method, are adopted to monitor the small deformation of the model. Hence, the distortion of the model could be accurately measured. In order to validate the performance of this innovative model test system, a 3D geomechanical test was conducted on a simulated deep-buried underground reservoir. The result shows that the radial convergence increases rapidly with the release of the stress in the reservoir. Moreover, the deformation increases with the increase of the gas production rate. This observation is consistence with field observation in petroleum engineering. The system is therefore capable of testing deep-buried engineering structures.

  16. Pain outcomes after surgery in patients with intramedullary spinal cord cavernous malformations.

    PubMed

    Deutsch, Harel

    2010-09-01

    The objective of the study was to quantify the improvement in pain levels for patients who have undergone surgery for intramedullary spinal cord cavernous malformations (SCCMs). The author reviewed medical records of patients who underwent surgery for an intramedullary SCCM between 2003 and 2010. Numerical pain scores (range 0-10) were recorded preoperatively and at follow-up. The follow-up period exceeded 1 year. Neurological status and subjective outcomes were assessed. Each patient underwent follow-up MR imaging. Five patients were identified with SCCMs who underwent surgery: 4 with thoracic and 1 with cervical lesions. Patients had been conservatively managed for an average of 5 years prior to surgery, and none had a history of acute hemorrhage or neurological deterioration during the observation period. The primary indication for surgery in each patient was pain, although 4 of 5 patients had some evidence of myelopathy on examination. Pain improved from a mean preoperative score of 8.6 to mean score of 2.0 (p < 0.01) at 1 month. Pain scores then increased to 3.7 (p < 0.01) at 1 year. All patients had some improvement in pain. No new motor weakness was noted, but all patients had increased symptoms of posterior-column dysfunction and numbness after surgery. Spinal cord intramedullary cavernous malformations are increasingly being diagnosed early with patients presenting with mostly pain symptoms. Removal of the lesion is reliably associated with improvement in pain scores but often the pain improvement is transient. While long-term worsening of pain scores occurs, at 1-year follow-up, patients reported pain scores were improved over preoperative scores. In all patients some degree of postoperative posterior-column dysfunction was present. Some of the immediate pain relief may be due to analgesia related to the myelotomy of newly described posterior column pain pathways. In patients with severe pain, surgery to remove SCCMs reduced the overall pain level at 1

  17. Bilateral Cavernous Sinus Thrombosis as First Manifestation of Primary Burkitt Lymphoma of the Thyroid Gland

    PubMed Central

    Moghaddasi, Mehdi; Nabovvati, Mona; Razmeh, Saeed

    2017-01-01

    Cavernous sinus thrombosis (CST) is a rare condition that is usually associated with infections, pregnancy, vasculitis and some types of medication, such as the contraceptive pill and paraneoplastic. Primary Burkitt lymphoma (PBL) of the thyroid gland is very uncommon and the clinical description of such cases has been largely limited to case reports. In this paper, we present a case of CST as the first manifestation of PBL of the thyroid gland. To the best of our knowledge, our patient is the first case report of PBL of the thyroid gland that presents with bilateral CST. PMID:28713532

  18. orbit-estimation: Fast orbital parameters estimator

    NASA Astrophysics Data System (ADS)

    Mackereth, J. Ted; Bovy, Jo

    2018-04-01

    orbit-estimation tests and evaluates the Stäckel approximation method for estimating orbit parameters in galactic potentials. It relies on the approximation of the Galactic potential as a Stäckel potential, in a prolate confocal coordinate system, under which the vertical and horizontal motions decouple. By solving the Hamilton Jacobi equations at the turning points of the horizontal and vertical motions, it is possible to determine the spatial boundary of the orbit, and hence calculate the desired orbit parameters.

  19. The Hot Orbit: Orbital Cellulitis

    PubMed Central

    Chaudhry, Imtiaz A.; Al-Rashed, Waleed; Arat, Yonca O.

    2012-01-01

    Orbital cellulitis is an uncommon condition previously associated with severe complications. If untreated, orbital cellulitis can be potentially sight and life threatening. It can affect both adults and children but has a greater tendency to occur in the pediatric age group. The infection most commonly originates from sinuses, eyelids or face, retained foreign bodies, or distant soources by hematogenous spread. It is characterized by eyelid edema, erythema, chemosis, proptosis, blurred vision, fever, headache, and double vision. A history of upper respiratory tract infection prior to the onset is very common especially in children. In the era prior to antibiotics, vision loss from orbital cellulitis was a dreaded complication. Currently, imaging studies for detection of orbital abcess, the use of antibiotics and early drainage have mitigated visual morbidity significantly. The purpose of this review is to describe current investigative strategies and management options in the treatment of orbital cellulitis, establish their effectiveness and possible complications due to late intervention. PMID:22346113

  20. Lunar Reconnaissance Orbiter Orbit Determination Accuracy Analysis

    NASA Technical Reports Server (NTRS)

    Slojkowski, Steven E.

    2014-01-01

    Results from operational OD produced by the NASA Goddard Flight Dynamics Facility for the LRO nominal and extended mission are presented. During the LRO nominal mission, when LRO flew in a low circular orbit, orbit determination requirements were met nearly 100% of the time. When the extended mission began, LRO returned to a more elliptical frozen orbit where gravity and other modeling errors caused numerous violations of mission accuracy requirements. Prediction accuracy is particularly challenged during periods when LRO is in full-Sun. A series of improvements to LRO orbit determination are presented, including implementation of new lunar gravity models, improved spacecraft solar radiation pressure modeling using a dynamic multi-plate area model, a shorter orbit determination arc length, and a constrained plane method for estimation. The analysis presented in this paper shows that updated lunar gravity models improved accuracy in the frozen orbit, and a multiplate dynamic area model improves prediction accuracy during full-Sun orbit periods. Implementation of a 36-hour tracking data arc and plane constraints during edge-on orbit geometry also provide benefits. A comparison of the operational solutions to precision orbit determination solutions shows agreement on a 100- to 250-meter level in definitive accuracy.

  1. Orbital cellulitis: a rare complication after orbital blowout fracture.

    PubMed

    Ben Simon, Guy J; Bush, Steven; Selva, Dinesh; McNab, Alan A

    2005-11-01

    To report the incidence of orbital cellulitis after orbital blowout fracture. Retrospective, noncomparative, interventional case series. All patients with orbital cellulitis and a history of recent orbital fracture. A medical record review of clinical history, imaging studies, and surgical and treatment outcome was performed. Resolution of orbital cellulitis and surgical and imaging findings. Four patients (3 male; mean age, 30 years [range, 4.5-58]) were treated for orbital cellulitis complicating orbital fracture. All patients had evidence of paranasal sinusitis before or after the orbital injury, and 2 also reported forceful nose blowing after sustaining orbital trauma. Although 3 patients received prophylactic oral antibiotics after the fracture, this failed to prevent infection. Sinusitis commenced 1 to 2 weeks before and as late as 5 weeks after orbital injury. All patients were treated with IV antibiotics. Two developed an orbital abscess that required surgical drainage; 1 patient improved after an endonasal maxillary antrostomy. One patient improved on IV antibiotics alone and underwent fracture repair at a later stage. These 4 patients represent 0.8% of all cases of orbital fractures treated in the study period. Orbital cellulitis is a rare complication of orbital fracture, and seems to be more common when paranasal sinus infection preexists or occurs within several weeks of the injury. Oral antibiotics given after the orbital injury may not prevent orbital cellulitis or abscess formation. Surgery may be required to drain orbital abscess or in nonresolving cellulitis to drain the paranasal sinuses. Fracture repair, if indicated, should be delayed, particularly if an alloplastic implant is used.

  2. Analysis of orbital perturbations acting on objects in orbits near geosynchronous earth orbit

    NASA Technical Reports Server (NTRS)

    Friesen, Larry J.; Jackson, Albert A., IV; Zook, Herbert A.; Kessler, Donald J.

    1992-01-01

    The paper presents a numerical investigation of orbital evolution for objects started in GEO or in orbits near GEO in order to study potential orbital debris problems in this region. Perturbations simulated include nonspherical terms in the earth's geopotential field, lunar and solar gravity, and solar radiation pressure. Objects simulated include large satellites, for which solar radiation pressure is insignificant, and small particles, for which solar radiation pressure is an important force. Results for large satellites are largely in agreement with previous GEO studies that used classical perturbation techniques. The orbit plane of GEO satellites placed in a stable plane orbit inclined approximately 7.3 deg to the equator experience very little precession, remaining always within 1.2 percent of their initial orientation. Solar radiation pressure generates two major effects on small particles: an orbital eccentricity oscillation anticipated from previous research, and an oscillation in orbital inclination.

  3. Solid Propulsion De-Orbiting and Re-Orbiting

    NASA Astrophysics Data System (ADS)

    Schonenborg, R. A. C.; Schoyer, H. F. R.

    2009-03-01

    With many "innovative" de-orbit systems (e.g. tethers, aero breaking, etc.) and with natural de-orbit, the place of impact of unburned spacecraft debris on Earth can not be determined accurately. The idea that satellites burn up completely upon re-entry is a common misunderstanding. To the best of our knowledge only rocket motors are capable of delivering an impulse that is high enough, to conduct a de-orbit procedure swiftly, hence to de-orbit at a specific moment that allows to predict the impact point of unburned spacecraft debris accurately in remote areas. In addition, swift de-orbiting will reduce the on-orbit time of the 'dead' satellite, which reduces the chance of the dead satellite being hit by other dead or active satellites, while spiralling down to Earth during a slow, 25 year, or more, natural de-orbit process. Furthermore the reduced on-orbit time reduces the chance that spacecraft batteries, propellant tanks or other components blow up and also reduces the time that the object requires tracking from Earth.The use of solid propellant for the de-orbiting of spacecraft is feasible. The main advantages of a solid propellant based system are the relatively high thrust and the facts that the system can be made autonomous quite easily and that the system can be very reliable. The latter is especially desirable when one wants to de-orbit old or 'dead' satellites that might not be able to rely anymore on their primary systems. The disadvantage however, is the addition of an extra system to the spacecraft as well as a (small) mass penalty. [1]This paper describes the above mentioned system and shows as well, why such a system can also be used to re-orbit spacecraft in GEO, at the end of their life to a graveyard orbit.Additionally the system is theoretically compared to an existing system, of which performance data is available.A swift market analysis is performed as well.

  4. Structural Stability Monitoring of a Physical Model Test on an Underground Cavern Group during Deep Excavations Using FBG Sensors.

    PubMed

    Li, Yong; Wang, Hanpeng; Zhu, Weishen; Li, Shucai; Liu, Jian

    2015-08-31

    Fiber Bragg Grating (FBG) sensors are comprehensively recognized as a structural stability monitoring device for all kinds of geo-materials by either embedding into or bonding onto the structural entities. The physical model in geotechnical engineering, which could accurately simulate the construction processes and the effects on the stability of underground caverns on the basis of satisfying the similarity principles, is an actual physical entity. Using a physical model test of underground caverns in Shuangjiangkou Hydropower Station, FBG sensors were used to determine how to model the small displacements of some key monitoring points in the large-scale physical model during excavation. In the process of building the test specimen, it is most successful to embed FBG sensors in the physical model through making an opening and adding some quick-set silicon. The experimental results show that the FBG sensor has higher measuring accuracy than other conventional sensors like electrical resistance strain gages and extensometers. The experimental results are also in good agreement with the numerical simulation results. In conclusion, FBG sensors could effectively measure small displacements of monitoring points in the whole process of the physical model test. The experimental results reveal the deformation and failure characteristics of the surrounding rock mass and make some guidance for the in situ engineering construction.

  5. Structural Stability Monitoring of a Physical Model Test on an Underground Cavern Group during Deep Excavations Using FBG Sensors

    PubMed Central

    Li, Yong; Wang, Hanpeng; Zhu, Weishen; Li, Shucai; Liu, Jian

    2015-01-01

    Fiber Bragg Grating (FBG) sensors are comprehensively recognized as a structural stability monitoring device for all kinds of geo-materials by either embedding into or bonding onto the structural entities. The physical model in geotechnical engineering, which could accurately simulate the construction processes and the effects on the stability of underground caverns on the basis of satisfying the similarity principles, is an actual physical entity. Using a physical model test of underground caverns in Shuangjiangkou Hydropower Station, FBG sensors were used to determine how to model the small displacements of some key monitoring points in the large-scale physical model during excavation. In the process of building the test specimen, it is most successful to embed FBG sensors in the physical model through making an opening and adding some quick-set silicon. The experimental results show that the FBG sensor has higher measuring accuracy than other conventional sensors like electrical resistance strain gages and extensometers. The experimental results are also in good agreement with the numerical simulation results. In conclusion, FBG sensors could effectively measure small displacements of monitoring points in the whole process of the physical model test. The experimental results reveal the deformation and failure characteristics of the surrounding rock mass and make some guidance for the in situ engineering construction. PMID:26404287

  6. Shuttle on-orbit rendezvous targeting: Circular orbits

    NASA Technical Reports Server (NTRS)

    Bentley, E. L.

    1972-01-01

    The strategy and logic used in a space shuttle on-orbit rendezvous targeting program are described. The program generates ascent targeting conditions for boost to insertion into an intermediate parking orbit, and generates on-orbit targeting and timeline bases for each maneuver to effect rendezvous with a space station. Time of launch is determined so as to eliminate any plane change, and all work was performed for a near-circular space station orbit.

  7. Interesting case of base of skull mass infiltrating cavernous sinuses.

    PubMed

    Singh, Achintya Dinesh; Soneja, Manish; Memon, Saba Samad; Vyas, Surabhi

    2016-11-16

    A man aged 35 years presented with chronic headache and earache of 1-year duration. He had progressive vision loss and diplopia since last 9 months. He also had pain over the face and episodic profuse epistaxis. On examination, perception of light was absent in the right eye and hand movements were detected at 4 m distance in the left eye. Imaging revealed a lobulated mass in the nasopharynx extending into the bilateral cavernous sinuses and sphenoid sinus with bony erosions. Biopsy of the nasopharyngeal mass revealed pathological features which are characteristic of IgG4 disease. His serum IgG4 levels and acute inflammatory markers were also elevated. The patient was started on oral corticosteroid therapy. Fever, headache and earache resolved early and there was gradual improvement in the vision of the left eye. After 6 months, visual acuity in the left eye was 6/9, but right eye visual acuity had no change. Follow-up imaging revealed a significant reduction in the size of the mass. 2016 BMJ Publishing Group Ltd.

  8. Follow-Up of 58 Traumatic Carotid-Cavernous Fistulas after Endovascular Detachable-Balloon Embolization at a Single Center

    PubMed Central

    Xu, Xiao-Quan; Liu, Sheng; Zu, Qing-Quan; Zhao, Lin-Bo; Xia, Jin-Guo; Zhou, Chun-Gao; Zhou, Wei-Zhong

    2013-01-01

    Background and Purpose This study evaluated the clinical value of detachable-balloon embolization for traumatic carotid-cavernous fistula (TCCF), focusing on the frequency, risk factors, and retreatment of recurrence. Methods Fifty-eight patients with TCCF underwent transarterial detachable-balloon embolization between October 2004 and March 2011. The clinical follow-up was performed every 3 months until up to 3 years postprocedure. Each patient was placed in either the recurrence group or the nonrecurrence group according to whether a recurrence developed after the first procedure. The relevant factors including gender, fistula location, interval between trauma and the interventional procedure, blood flow in the carotid-cavernous fistula, number of balloons, and whether the internal carotid artery (ICA) was sacrificed were evaluated. Results All 58 TCCFs were successfully treated with transarterial balloon embolization, including 7 patients with ICA sacrifice. Recurrent fistulas occurred in seven patients during the follow-up period. Univariate analysis indicated that the interval between trauma and the interventional procedure (p=0.006) might be the main factor related to the recurrence of TCCF. The second treatments involved ICA sacrifice in two patients, fistula embolization with balloons in four patients, and placement of a covered stent in one patient. Conclusions Detachable balloons can still serve as the first-line treatment for TCCFs and recurrent TCCFs despite having a nonnegligible recurrence rate. Shortening the interval between trauma and the interventional procedure may reduce the risk of recurrence. PMID:23626645

  9. The effect of audio tours on learning and social interaction: An evaluation at Carlsbad Caverns National Park

    NASA Astrophysics Data System (ADS)

    Novey, Levi T.; Hall, Troy E.

    2007-03-01

    Auditory forms of nonpersonal communication have rarely been evaluated in informal settings like parks and museums. This study evaluated the effect of an interpretive audio tour on visitor knowledge and social behavior at Carlsbad Caverns National Park. A cross-sectional pretest/posttest quasi-experimental design compared the responses of audio tour users (n = 123) and nonusers (n = 131) on several knowledge questions. Observations (n = 700) conducted at seven sites within the caverns documented sign reading, time spent listening to the audio, within group conversation, and other social behaviors for a different sample of visitors. Pretested tour users and nonusers did not differ in visitor characteristics, knowledge, or attitude variables, suggesting the two populations were similar. On a 12-item knowledge quiz, tour users' scores increased from 5.7 to 10.3, and nonusers' scores increased from 6.2 to 8.4. Most visitors were able to identify some of the park's major messages when presented with a multiple-choice question, but more audio users than nonusers identified resource preservation as a primary message in an open-ended question. Based on observations, audio tour users and nonusers did not differ substantially in their interactions with other members of their group or in their reading of interpretive signs in the cave. Audio tour users had positive reactions to the tour, and these reactions, coupled with the positive learning outcomes and negligible effects on social interaction, suggest that audio tours can be an effective communication medium in informal educational settings.

  10. [Orbital inflammation].

    PubMed

    Mouriaux, F; Coffin-Pichonnet, S; Robert, P-Y; Abad, S; Martin-Silva, N

    2014-12-01

    Orbital inflammation is a generic term encompassing inflammatory pathologies affecting all structures within the orbit : anterior (involvement up to the posterior aspect of the globe), diffuse (involvement of intra- and/or extraconal fat), apical (involvement of the posterior orbit), myositis (involvement of only the extraocular muscles), dacryoadenitis (involvement of the lacrimal gland). We distinguish between specific inflammation and non-specific inflammation, commonly referred to as idiopathic inflammation. Specific orbital inflammation corresponds to a secondary localization of a "generalized" disease (systemic or auto-immune). Idiopathic orbital inflammation corresponds to uniquely orbital inflammation without generalized disease, and thus an unknown etiology. At the top of the differential diagnosis for specific or idiopathic orbital inflammation are malignant tumors, represented most commonly in the adult by lympho-proliferative syndromes and metastases. Treatment of specific orbital inflammation begins with treatment of the underlying disease. For idiopathic orbital inflammation, treatment (most often corticosteroids) is indicated above all in cases of visual loss due to optic neuropathy, in the presence of pain or oculomotor palsy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  11. A Continuous Holocene Record of Hydroclimate from Kartchner Cavern, AZ, Supported by Multiyear Dripwater Monitoring

    NASA Astrophysics Data System (ADS)

    Cole, J. E.; Hlohowskyj, S.; Vetter, L.; King, J.; Casavant, R. R.; Woodhead, J. D.; Drysdale, R.; Truebe, S.; Henderson, G. M.

    2017-12-01

    In the arid southwest, hydroclimatic variability is critical to natural and human systems. Cave records provide the chance to reconstruct past variations in moisture, including the seasonal hydroclimatic response to known forcings such as the seasonal distribution of insolation. At Kartchner Caverns State Park, AZ, a sample dating to 12,000 years before present reveals a continuous Holocene history of the Southwest monsoon in its stable isotope content. We interpret the large ( 4‰) changes in speleothem d18O in terms of seasonal precipitation balance, based on modern isotope studies. The Kartchner record confirms a shorter ( 6500 yr) reconstruction from the neighboring Cave of the Bells in describing a strong trend of declining monsoon moisture during the Holocene. The Kartchner sample reveals an early Holocene monsoon peak defined by a broad δ18O peak between 7000 and 9000 years ago, following a gradual strengthening from the start of the record. Between 7000-2000 years ago, the monsoon weakened, and the oxygen isotope values show no trend over the past 2000 years. Substantial multidecadal-multicentury variability is present throughout the record. This pattern is consistent with a sensitive response of the Southwest monsoon to orbital forcing of seasonal radiation. A new laser-ICPMS multi-element dataset spans the past 2400 years and adds information to our isotope-based reconstruction. In particular, Ba and Sr highlight intervals of overall wet and dry conditions, complementing the isotopic record of seasonal precipitation distribution. Dripwater monitoring since 2011 at 4 sites in the cave allows us to identify seasonal and interannual controls on the isotopic and elemental variations of dripwater. Drips differ in their isotopic behavior, with some dominated by relatively steady, low (winter) values and others exhibiting highly variable δ18O. This study provides one of the first cave-based reconstructions of the North American monsoon spanning the entire

  12. PyORBIT: A Python Shell For ORBIT

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

    Jean-Francois Ostiguy; Jeffrey Holmes

    2003-07-01

    ORBIT is code developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. The code is structured as a collection of external C++ modules for SuperCode, a high level interpreter shell developed at LLNL in the early 1990s. SuperCode is no longer actively supported and there has for some time been interest in replacing it by a modern scripting language, while preserving the feel of the original ORBIT program. In this paper, we describe a new version of ORBIT where the role of SuperCode is assumed by Python, a free, well-documented and widely supported object-oriented scripting language. Wemore » also compare PyORBIT to ORBIT from the standpoint of features, performance and future expandability.« less

  13. Rehabilitation of orbital cavity after orbital exenteration using polymethyl methacrylate orbital prosthesis.

    PubMed

    Jain, Sumeet; Jain, Parul

    2016-01-01

    Squamous cell carcinoma of the eyelid is the second most common malignant neoplasm of the eye with the incidence of 0.09 and 2.42 cases/100 000 people. Orbital invasion is a rare complication but, if recognized early, can be treated effectively with exenteration. Although with advancements in technology such as computer-aided design and computer-aided manufacturing, material science, and retentive methods like implants, orbital prosthesis with stock ocular prosthesis made of methyl methacrylate retained by anatomic undercuts is quiet effective and should not be overlooked and forgotten. This clinical report describes prosthetic rehabilitation of two male patients with polymethyl methacrylate resin orbital prosthesis after orbital exenteration, for squamous cell carcinoma of the upper eyelid. The orbital prosthesis was sufficiently retained by hard and soft tissue undercuts without any complications. The patients using the prosthesis are quite satisfied with the cosmetic results and felt comfortable attending the social events.

  14. A new model of cavern diameter based on a validated CFD study on stirring of a highly shear-thinning fluid.

    PubMed

    Story, Anna; Jaworski, Zdzisław

    2017-01-01

    Results of numerical simulations of momentum transfer for a highly shear-thinning fluid (0.2% Carbopol) in a stirred tank equipped with a Prochem Maxflo T type impeller are presented. The simulation results were validated using LDA data and both tangential and axial force measurements in the laminar and early transitional flow range. A good agreement between the predicted and experimental results of the local fluid velocity components was found. From the predicted and experimental values of both tangential and axial forces, the power number, Po , and thrust number, Th , were also calculated. Values of the absolute relative deviations were below 4.0 and 10.5%, respectively, for Po and Th , which confirms a satisfactory agreement with experiments. An intensive mixing zone, known as cavern, was observed near the impeller. In this zone, the local values of fluid velocity, strain rate, Metzner-Otto coefficient, shear stress and intensity of energy dissipation were all characterized by strong variability. Based on the results of experimental study a new model using non-dimensional impeller force number was proposed to predict the cavern diameter. Comparative numerical simulations were also carried out for a Newtonian fluid (water) and their results were similarly well verified using LDA measurements, as well as experimental power number values.

  15. Numerical simulation for the coupled thermo-mechanical performance of a lined rock cavern for underground compressed air energy storage

    NASA Astrophysics Data System (ADS)

    Zhou, Shu-Wei; Xia, Cai-Chu; Zhao, Hai-Bin; Mei, Song-Hua; Zhou, Yu

    2017-12-01

    Compressed air energy storage (CAES) is a technology that uses compressed air to store surplus electricity generated from low power consumption time for use at peak times. This paper presents a thermo-mechanical modeling for the thermodynamic and mechanical responses of a lined rock cavern used for CAES. The simulation was accomplished in COMSOL Multiphysics and comparisons of the numerical simulation and some analytical solutions validated the thermo-mechanical modeling. Air pressure and temperatures in the sealing layer and concrete lining exhibited a similar trend of ‘up-down-down-up’ in one cycle. Significant temperature fluctuation occurred only in the concrete lining and sealing layer, and no strong fluctuation was observed in the host rock. In the case of steel sealing, principal stresses in the sealing layer were larger than those in the concrete and host rock. The maximum compressive stresses of the three layers and the displacement on the cavern surface increased with the increase of cycle number. However, the maximum tensile stresses exhibited the opposite trend. Polymer sealing achieved a relatively larger air temperature and pressure compared with steel and air-tight concrete sealing. For concrete layer thicknesses of 0 and 0.1 m and an initial air pressure of 4.5 MPa, the maximum rock temperature could reach 135 °C and 123 °C respectively in a 30 day simulation.

  16. Use of antithrombotic agents in patients with intracerebral cavernous malformations.

    PubMed

    Flemming, Kelly D; Link, Michael J; Christianson, Teresa J H; Brown, Robert D

    2013-01-01

    The goal of this study was to determine the risk of using antithrombotic agents in patients with established intracerebral cavernous malformations (ICMs). From a previously described cohort of 292 patients with radiographically defined ICMs, 40 required an antithrombotic after the ICM was diagnosed. Patients underwent follow-up to determine the incidence of hemorrhage. The mean age of these 40 patients was 62.4 years; there were 21 male and 19 female patients. Five (12.5%) of the 40 patients initially presented with hemorrhage and 4 (10%) had multiple ICMs. Of these patients, 32 were placed on an antiplatelet agent alone, 6 on an anticoagulant alone, and 2 were placed on both. In patients necessitating any antithrombotic agent, 1 patient developed a prospective hemorrhage over the 258 person-years of follow-up (prospective hemorrhage rate 0.41% per person-year). Antithrombotics likely do not precipitate hemorrhage in patients with known ICMs. However, caution should be exercised in the use of antithrombotics in patients with ICMs at high risk for hemorrhage. The risks and benefits of antithrombotics in each situation should be carefully weighed against the natural history of ICM.

  17. Computer-aided diagnosis of cavernous malformations in brain MR images.

    PubMed

    Wang, Huiquan; Ahmed, S Nizam; Mandal, Mrinal

    2018-06-01

    Cavernous malformation or cavernoma is one of the most common epileptogenic lesions. It is a type of brain vessel abnormality that can cause serious symptoms such as seizures, intracerebral hemorrhage, and various neurological disorders. Manual detection of cavernomas by physicians in a large set of brain MRI slices is a time-consuming and labor-intensive task and often delays diagnosis. In this paper, we propose a computer-aided diagnosis (CAD) system for cavernomas based on T2-weighted axial plane MRI image analysis. The proposed technique first extracts the brain area based on atlas registration and active contour model, and then performs template matching to obtain candidate cavernoma regions. Texture, the histogram of oriented gradients and local binary pattern features of each candidate region are calculated, and principal component analysis is applied to reduce the feature dimensionality. Support vector machines (SVMs) are finally used to classify each region into cavernoma or non-cavernoma so that most of the false positives (obtained by template matching) are eliminated. The performance of the proposed CAD system is evaluated and experimental results show that it provides superior performance in cavernoma detection compared to existing techniques. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Neuroprotective and Nerve Regenerative Approaches for Treatment of Erectile Dysfunction after Cavernous Nerve Injury

    PubMed Central

    Campbell, Jeffrey D.; Burnett, Arthur L.

    2017-01-01

    Erectile dysfunction (ED) is a significant cause of reduced quality of life in men and their partners. Cavernous nerve injury (CNI) during pelvic surgery results in ED in greater than 50% of patients, regardless of additional patient factors. ED related to CNI is difficult to treat and typically poorly responsive to first- and second-line therapeutic options. Recently, a significant amount of research has been devoted to exploring neuroprotective and neuroregenerative approaches to salvage erectile function in patients with CNI. In addition, therapeutic options such as neuregulins, immunophilin ligands, gene therapy, stem cell therapy and novel surgical strategies, have shown benefit in pre-clinical, and limited clinical studies. In the era of personalized medicine, these new therapeutic technologies will be the future of ED treatment and are described in this review. PMID:28820434

  19. The orbit properties of colliding co-orbiting bodies

    NASA Technical Reports Server (NTRS)

    Freeman, John W.

    1987-01-01

    It is generally assumed that an ensemble of small bodies located in similar Keplarian orbits will, because of collisions, tend to disperse into more and more dissimilar orbits. This theory was challenged. Alfven maintains that for the case where the time between collisions is longer than the orbit period and the collisions are essentially inelastic the orbits and velocities will become more similar. This gives rise to the concepts of negative diffusion and jet streams. It is proposed that this question might be investigated experimentally using the space station. The proposed experiment is briefly described.

  20. Orbits: Computer simulation

    NASA Technical Reports Server (NTRS)

    Muszynska, A.

    1985-01-01

    In rotating machinery dynamics an orbit (Lissajous curve) represents the dynamic path of the shaft centerline motion during shaft rotation and resulting precession. The orbit can be observed with an oscilloscope connected to XY promixity probes. The orbits can also be simulated by a computer. The software for HP computer simulates orbits for two cases: (1) Symmetric orbit with four frequency components with different radial amplitudes and relative phase angles; and (2) Nonsymmetric orbit with two frequency components with two different vertical/horizontal amplitudes and two different relative phase angles. Each orbit carries a Keyphasor mark (one-per-turn reference). The frequencies, amplitudes, and phase angles, as well as number of time steps for orbit computation, have to be chosen and introduced to the computer by the user. The orbit graphs can be observed on the computer screen.

  1. Comparison of Low Earth Orbit and Geosynchronous Earth Orbits

    NASA Technical Reports Server (NTRS)

    Drummond, J. E.

    1980-01-01

    The technological, environmental, social, and political ramifications of low Earth orbits as compared to geosynchronous Earth orbits for the solar power satellite (SPS) are assessed. The capital cost of the transmitting facilities is dependent on the areas of the antenna and rectenna relative to the requirement of high efficiency power transmission. The salient features of a low orbit Earth orbits are discussed in terms of cost reduction efforts.

  2. Orbit determination singularities in the Doppler tracking of a planetary orbiter

    NASA Technical Reports Server (NTRS)

    Wood, L. J.

    1985-01-01

    On a number of occasions, spacecraft launched by the U.S. have been placed into orbit about the moon, Venus, or Mars. It is pointed out that, in particular, in planetary orbiter missions two-way coherent Doppler data have provided the principal data type for orbit determination applications. The present investigation is concerned with the problem of orbit determination on the basis of Doppler tracking data in the case of a spacecraft in orbit about a natural body other than the earth or the sun. Attention is given to Doppler shift associated with a planetary orbiter, orbit determination using a zeroth-order model for the Doppler shift, and orbit determination using a first-order model for the Doppler shift.

  3. Measurements of the STS orbiter's angular stability during in-orbit operations

    NASA Technical Reports Server (NTRS)

    Neupert, Werner M.; Epstein, Gabriel L.; Houston, James; Zarechnak, Andrew

    1995-01-01

    We report on measurements of the angular stability, commonly called 'jitter', of the STS Orbiter during normal operations in space. Measurements were carried out by measuring optically the Orbiter's roll and pitch orientation relative to the solar vector as the orbiter was held in a -Z(sub 0) solar inertial orientation (orbiter bay oriented toward the Sun). We also report observations of an interesting perturbation to the orbiter's orientation noted by the crew during the STS-60 mission. These data may be useful in analyzing the in-orbit response of the Orbiter to thruster firings and other applied torques, and may aid in the planning of future experiments that require fine-pointed operations by the orbiter.

  4. Overall view of the Orbiter Servicing Structure within the Orbiter ...

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

    Overall view of the Orbiter Servicing Structure within the Orbiter Processing Facility at Kennedy Space Center. Can you see any hint of the Orbiter Discovery? It is in there. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  5. Flow diversion in vasculitic intracranial aneurysms? Repair of giant complex cavernous carotid aneurysm in polyarteritis nodosa using Pipeline embolization devices: first reported case.

    PubMed

    Santos, Jaime Martinez; Kaderali, Zul; Spears, Julian; Rubin, Laurence A; Marotta, Thomas R

    2015-05-29

    Intracranial aneurysms in polyarteritis nodosa (PAN) are exceedingly rare lesions with unpredictable behavior that pose real challenges to microsurgical and endovascular interventions owing to their inflammatory nature. We introduce a safe and effective alternative for treating these aneurysms using Pipeline embolization devices (PEDs). A 20-year-old man presented with diplopia, headaches, chronic abdominal pain, and weight loss. Diagnostic evaluations confirmed PAN, including bilateral giant cavernous carotid aneurysms. Cyclophosphamide and steroids achieved significant and sustained clinical improvement, with a decision to follow the aneurysms serially. Seven years later the left unruptured aneurysm enlarged, causing a sudden severe headache and a cavernous sinus syndrome. Treatment of the symptomatic aneurysm was pursued using flow diversion (PED) and the internal carotid artery was successfully reconstructed with a total of four overlapping PEDs. At 6 months follow-up, complete exclusion of the aneurysm was demonstrated, with symptomatic recovery. This is the first description of using a flow-diverting technique in an inflammatory vasculitis. In this case, PEDs not only attained a definitive closure of the aneurysm but also reconstructed the damaged and fragile arterial segment affected with vasculitis. 2015 BMJ Publishing Group Ltd.

  6. nNOS-positive minor-branches of the dorsal penile nerves is associated with erectile function in the bilateral cavernous injury model of rats.

    PubMed

    Chen, Yen-Lin; Chao, Ting-Ting; Wu, Yi-No; Chen, Meng-Chuan; Lin, Ying-Hung; Liao, Chun-Hou; Wu, Chien-Chih; Chen, Kuo-Chiang; Chou, Shang-Shing P; Chiang, Han-Sun

    2018-01-17

    The changes in neuronal nitric oxide synthases (nNOS) in the dorsal penile nerves (DPNs) are consistent with cavernous nerve (CN) injury in rat models. However, the anatomical relationship and morphological changes between the minor branches of the DPNs and the CNs after injury have never been clearly explored. There were forty 12 week old male Sprague-Dawley rats receiving bilateral cavernous nerve injury (BCNI). Erectile function of intracavernous pressure and mean arterial pressure were measured. The histology and ultrastructure with H&E stain, Masson's trichrome stain and immunohistochemical stains were applied on the examination of CNs and DPNs. We demonstrated communicating nerve branches between the DPNs and the CNs in rats. The greatest damage and lowest erectile function were seen in the 14 th day and partially recovered in the 28 th day after BCNI. The nNOS positive DPN minor branches' number was significantly correlated with erectile function. The sub-analysis of the number of nNOS positive DPN minor branches also matched with the time course of the erectile function after BCNI. We suggest the regeneration of the DPNs minor branches would ameliorate the erectile function in BCNI rats.

  7. Deadly Sunflower Orbits

    NASA Astrophysics Data System (ADS)

    Hamilton, Douglas P.

    2018-04-01

    Solar radiation pressure is usually very effective at removing hazardous millimeter-sized debris from distant orbits around asteroidsand other small solar system bodies (Hamilton and Burns 1992). Theprimary loss mechanism, driven by the azimuthal component of radiationpressure, is eccentricity growth followed by a forced collision withthe central body. One large class of orbits, however, neatly sidestepsthis fate. Orbits oriented nearly perpendicular to the solar directioncan maintain their face-on geometry, oscillating slowly around a stableequilibrium orbit. These orbits, designated sunflower orbits, arerelated to terminator orbits studied by spacecraft mission designers(Broschart etal. 2014).Destabilization of sunflower orbits occurs only for particles smallenough that radiation pressure is some tens of percent the strength ofthe central body's direct gravity. This greatly enhanced stability,which follows from the inability of radiation incident normal to theorbit to efficiently drive eccentricities, presents a threat tospacecraft missions, as numerous dangerous projectiles are potentiallyretained in orbit. We have investigated sunflower orbits insupport of the New Horizons, Aida, and Lucy missions and find thatthese orbits are stable for hazardous particle sizes at asteroids,comets, and Kuiper belt objects of differing dimensions. Weinvestigate the sources and sinks for debris that might populate suchorbits, estimate timescales and equilibrium populations, and willreport on our findings.

  8. Successful Transarterial Guglielmi Detachable Coil Embolization of Post-Traumatic Fistula between a Posterior Communicating Artery Aneurysm and the Cavernous Sinus

    PubMed Central

    Chen, Y.; Jiang, D-Y.; Tan, H-Q.; Wang, L-H.; Chen, X-Y.; Sun, J-H.

    2009-01-01

    Summary We describe a case of a post-traumatic posterior communicating artery (PCoA) aneurysmcavernous sinus fistula, which is an extremely rare complication of craniocerebral trauma, successfully treated with endosaccular coil embolization via transarterial route. Endosaccular embolization with Guglielmi detachable coils via transarterial route appears to be a feasible, effective and minimally invasive option for the treatment of post-traumatic fistula between the PCoA aneurysm with a small ostia and the cavernous sinus in the subacute phase. PMID:20465883

  9. Management of supratentorial cavernous malformations: craniotomy versus gammaknife radiosurgery.

    PubMed

    Shih, Yang-Hsin; Pan, David Hung-Chi

    2005-02-01

    Although craniotomy is the preferred treatment for symptomatic solitary supratentorial cavernous malformation (CM), radiosurgery is also an option. Our aim was to see which of these strategies was the most effective and under what circumstances. Of the 46 patients with solitary supratentorial CM that we retrospectively studied, 24 presented with seizures, 16 with focal neurological deficits due to intracerebral hemorrhage, and 6 with both seizures and bleeding. Sixteen were treated with craniotomy and 30 with gammaknife radiosurgery (GKRS). The main outcome measures for comparing craniotomy with GKRS were the proportion of postoperative seizure-free patients and the proportion of patients in whom no rebleeding occurred. Of patients presenting with seizures with/without bleeding, a significantly higher proportion of the craniotomy group than the GKRS group became and remained seizure-free (11/14 [79%] versus 4/16 [25%]; P < 0.002), and of those presenting with bleeding with/without seizures, a somewhat (though nonsignificantly) higher proportion did not rebleed (4/4 [100%] versus 12/18 [67%]) after surgery. The remaining 2 of the 16 craniotomy patients did not rebleed and had no residual tumor at follow up. Twelve of the 30 GKRS patients had evidence of tumor regression at follow up. In the clinical management of solitary supratentorial CM, craniotomy for lesionectomy resulted in better seizure control and rebleeding avoidance than GKRS.

  10. Lunar orbiting prospector

    NASA Technical Reports Server (NTRS)

    1988-01-01

    One of the prime reasons for establishing a manned lunar presence is the possibility of using the potential lunar resources. The Lunar Orbital Prospector (LOP) is a lunar orbiting platform whose mission is to prospect and explore the Moon from orbit in support of early lunar colonization and exploitation efforts. The LOP mission is divided into three primary phases: transport from Earth to low lunar orbit (LLO), operation in lunar orbit, and platform servicing in lunar orbit. The platform alters its orbit to obtain the desired surface viewing, and the orbit can be changed periodically as needed. After completion of the inital remote sensing mission, more ambitious and/or complicated prospecting and exploration missions can be contemplated. A refueled propulsion module, updated instruments, or additional remote sensing packages can be flown up from the lunar base to the platform.

  11. Forbidden tangential orbit transfers between intersecting Keplerian orbits

    NASA Technical Reports Server (NTRS)

    Burns, Rowland E.

    1990-01-01

    The classical problem of tangential impulse transfer between coplanar Keplerian orbits is addressed. A completely analytic solution which does not rely on sequential calculation is obtained and this solution is used to demonstrate that certain initially chosen angles can produce singularities in the parameters of the transfer orbit. A necessary and sufficient condition for such singularities is that the initial and final orbits intersect.

  12. Frozen Orbits-Near Constant or Beneficially Varying Orbital Parameters.

    DTIC Science & Technology

    1986-05-15

    89 6.3 Equatorial Near-Circular Orbits ............................... 92 6.4 Stable and Unstable Equilibrium Points ...Angle Libration Period......................................... 78 5-2 Lunar Gravitational Effect on Near-Circular Orbits .................... 80 5-3...6-1 Period of Oscillation about the Stable Equilibrium Point ............... 102 FIGURES Figure 2.1 Orbital Parameters

  13. Spontaneous Recovery of Cavernous Nerve Crush Injury

    PubMed Central

    Kim, Hyo Jong; Kim, Ha Young; Kim, Sung Young; Lee, Seong Ho; Lee, Won Ki

    2011-01-01

    Purpose To investigate pathophysiological consequences and spontaneous recovery after cavernous nerve crush injury (CNCI) in a rat model. Materials and Methods Twenty 4-week-old male Sprague-Dawley rats were divided into the following groups: sham-operated group (n=10) and bilateral CNCI groups (n=10) for two different durations (12 and 24 weeks). At both time points, CN electrical stimulation was used to assess erectile function by measuring the intracavernous pressure. The expression of hypoxia inducible factor (HIF)-1α and sonic hedgehog (SHH) was examined in penile tissue. Immunohistochemical staining was performed for nerve growth factor (NGF), endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and smooth muscle α-actin. Results CNCI significantly decreased erectile function at 12 weeks (51.7% vs. 71.9%, mean ICP/BP ratio, p<0.05) and increased the expression of HIF-1α and decreased the expression of eNOS, nNOS, and SHH. At 24 weeks, erectile function in the CNCI group was improved with no significant difference versus the sham group (70.5% vs. 63.3%, mean ICP/BP ratio, p<0.05) or the CN group at 12 weeks (51.7% vs. 63.3%, mean ICP/BP ratio, p<0.05). By RT-PCR, the increase in HIF-1α and decrease in SHH mRNA was restored at 24 weeks. By immunohistochemistry, the expression of eNOS and nNOS was increased at 24 weeks. Conclusions CN injury induces significantly impaired erectile function and altered gene and protein expression, which suggests that local hypoxic and inflammatory processes may contribute to this change. Significant spontaneous recovery of erectile function was observed at 6 months after CN crush injury. PMID:21927704

  14. Rashba spin-orbit coupling and orbital chirality in magnetic bilayers

    NASA Astrophysics Data System (ADS)

    Lee, Hyun-Woo

    2013-03-01

    The phenomenon of the Rashba spin-orbit coupling is examined theoretically for an ultrathin magnetic layer in contact with a non-magnetic heavy metal layer. From first-principles calculation, large Rashba parameter of order 1 eV .Å is obtained, which is strong enough to generate large spin transfer torque of spin-orbit coupling origin. Large Rashba parameter is attributed to the orbital mixing of 3 d magnetic atoms and non-magnetic heavy elements with significant atomic spin-orbit coupling. Interestingly the magnitude and sign of the parameter vary from energy bands to bands, which we attribute to band-specific chiral ordering of orbital angular momentum. Through a simple tight-binding model analysis, we demonstrate that d-orbital hybridization allowed by the breaking of structural inversion symmetry generates band-specific chiral ordering of orbital angular momentum, which combines with atomic spin-orbit coupling to give rise to band-specific Rashba parameter. The band-dependence of the Rashba parameter is discussed in connection with recent experiments and we argue that the dependence may be utilized to enhance device application potentials. This work is supported by NRF grant (2010-0008529, 2011-0015631, 2010-0014109, 2011-0030789).

  15. Temperature-controlled optical stimulation of the rat prostate cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Hutchens, Thomas C.; McClain, Michael A.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2013-06-01

    Optical nerve stimulation (ONS) may be useful as a diagnostic tool for intraoperative identification and preservation of the prostate cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. Successful ONS requires elevating the nerve temperature to within a narrow range (˜42 to 47°C) for nerve activation without thermal damage to the nerve. This preliminary study explores a prototype temperature-controlled optical nerve stimulation (TC-ONS) system for maintaining a constant (±1°C) nerve temperature during short-term ONS of the rat prostate CNs. A 150-mW, 1455-nm diode laser was operated in continuous-wave mode, with and without temperature control, during stimulation of the rat CNs for 15 to 30 s through a fiber optic probe with a 1-mm-diameter spot. A microcontroller opened and closed an in-line mechanical shutter in response to an infrared sensor, with a predetermined temperature set point. With TC-ONS, higher laser power settings were used to rapidly and safely elevate the CNs to a temperature necessary for a fast intracavernous pressure response, while also preventing excessive temperatures that would otherwise cause thermal damage to the nerve. With further development, TC-ONS may provide a rapid, stable, and safe method for intraoperative identification and preservation of the prostate CNs.

  16. Orbit Software Suite

    NASA Technical Reports Server (NTRS)

    Osgood, Cathy; Williams, Kevin; Gentry, Philip; Brownfield, Dana; Hallstrom, John; Stuit, Tim

    2012-01-01

    Orbit Software Suite is used to support a variety of NASA/DM (Dependable Multiprocessor) mission planning and analysis activities on the IPS (Intrusion Prevention System) platform. The suite of Orbit software tools (Orbit Design and Orbit Dynamics) resides on IPS/Linux workstations, and is used to perform mission design and analysis tasks corresponding to trajectory/ launch window, rendezvous, and proximity operations flight segments. A list of tools in Orbit Software Suite represents tool versions established during/after the Equipment Rehost-3 Project.

  17. Unilateral facial palsy in an infant: an unusual presentation of familial multiple cerebral cavernous malformation

    PubMed Central

    Zakaria, Zaitun; Kaliaperumal, Chandrasekaran; Caird, John; Sattar, Mohammad

    2012-01-01

    Cerebral cavernous malformation (CCM) in infants tends to have genetic predisposition. These cavernomas have a progressive course of events and associated neurological symptoms with increase in age. They most commonly present with seizure and syndrome of increased intracranial pressure comprising of headache, vomiting and focal neurological signs. We describe a case of a 7-month-old infant who presented with an acute onset of right facial paralysis with a background of familial CCM. The CT and MRI scan revealed fresh haemorrhage in the right cerebellar and pontine cavernomas with surrounding oedema and no evidence of obstructive hydrocephalus. These two cavernomas re-bled in a week duration causing episodes of incessant crying and irritability. After discussing the pros and cons of treatment, owing to stable clinical status, the patient is currently been managed conservatively. PMID:23203183

  18. A Comparison of Simplified Two-dimensional Flow Models Exemplified by Water Flow in a Cavern

    NASA Astrophysics Data System (ADS)

    Prybytak, Dzmitry; Zima, Piotr

    2017-12-01

    The paper shows the results of a comparison of simplified models describing a two-dimensional water flow in the example of a water flow through a straight channel sector with a cavern. The following models were tested: the two-dimensional potential flow model, the Stokes model and the Navier-Stokes model. In order to solve the first two, the boundary element method was employed, whereas to solve the Navier-Stokes equations, the open-source code library OpenFOAM was applied. The results of numerical solutions were compared with the results of measurements carried out on a test stand in a hydraulic laboratory. The measurements were taken with an ADV probe (Acoustic Doppler Velocimeter). Finally, differences between the results obtained from the mathematical models and the results of laboratory measurements were analysed.

  19. Impact of GNSS orbit modeling on LEO orbit and gravity field determination

    NASA Astrophysics Data System (ADS)

    Arnold, Daniel; Meyer, Ulrich; Sušnik, Andreja; Dach, Rolf; Jäggi, Adrian

    2017-04-01

    On January 4, 2015 the Center for Orbit Determination in Europe (CODE) changed the solar radiation pressure modeling for GNSS satellites to an updated version of the empirical CODE orbit model (ECOM). Furthermore, since September 2012 CODE operationally computes satellite clock corrections not only for the 3-day long-arc solutions, but also for the non-overlapping 1-day GNSS orbits. This provides different sets of GNSS products for Precise Point Positioning, as employed, e.g., in the GNSS-based precise orbit determination of low Earth orbiters (LEOs) and the subsequent Earth gravity field recovery from kinematic LEO orbits. While the impact of the mentioned changes in orbit modeling and solution strategy on the GNSS orbits and geophysical parameters was studied in detail, their implications on the LEO orbits were not yet analyzed. We discuss the impact of the update of the ECOM and the influence of 1-day and 3-day GNSS orbit solutions on zero-difference LEO orbit and gravity field determination, where the GNSS orbits and clock corrections, as well as the Earth rotation parameters are introduced as fixed external products. Several years of kinematic and reduced-dynamic orbits for the two GRACE LEOs are computed with GNSS products based on both the old and the updated ECOM, as well as with 1- and 3-day GNSS products. The GRACE orbits are compared by means of standard validation measures. Furthermore, monthly and long-term GPS-only and combined GPS/K-band gravity field solutions are derived from the different sets of kinematic LEO orbits. GPS-only fields are validated by comparison to combined GPS/K-band solutions, while the combined solutions are validated by analysis of the formal errors, as well as by comparing them to the combined GRACE solutions of the European Gravity Service for Improved Emergency Management (EGSIEM) project.

  20. Diagrams for comprehensive molecular orbital-based chemical reaction analyses: reactive orbital energy diagrams.

    PubMed

    Tsuneda, Takao; Singh, Raman Kumar; Chattaraj, Pratim Kumar

    2018-05-15

    Reactive orbital energy diagrams are presented as a tool for comprehensively performing orbital-based reaction analyses. The diagrams rest on the reactive orbital energy theory, which is the expansion of conceptual density functional theory (DFT) to an orbital energy-based theory. The orbital energies on the intrinsic reaction coordinates of fundamental reactions are calculated by long-range corrected DFT, which is confirmed to provide accurate orbital energies of small molecules, combining with a van der Waals (vdW) correlation functional, in order to examine the vdW effect on the orbital energies. By analysing the reactions based on the reactive orbital energy theory using these accurate orbital energies, it is found that vdW interactions significantly affect the orbital energies in the initial reaction processes and that more than 70% of reactions are determined to be initially driven by charge transfer, while the remaining structural deformation (dynamics)-driven reactions are classified into identity, cyclization and ring-opening, unimolecular dissociation, and H2 reactions. The reactive orbital energy diagrams, which are constructed using these results, reveal that reactions progress so as to delocalize the occupied reactive orbitals, which are determined as contributing orbitals and are usually not HOMOs, by hybridizing the unoccupied reactive orbitals, which are usually not LUMOs. These diagrams also raise questions about conventional orbital-based diagrams such as frontier molecular orbital diagrams, even for the well-established interpretation of Diels-Alder reactions.

  1. Tumors masquerading in patients with thyroid eye disease.

    PubMed

    Griepentrog, Gregory J; Burkat, Cat N; Kikkawa, Don O; Lucarelli, Mark J

    2013-08-01

    Thyroid eye disease (TED) is the most common cause of proptosis in adults. The external manifestations of TED are characteristic and the diagnosis is typically made without imaging. Although there are multiple descriptions of primary and secondary orbital tumors initially mistaken for TED in the literature, there are limited reports detailing the findings of patients with long-standing TED whom developed an orbital tumor at a later date. Herein, we present a 6-year retrospective multi-center report of three patients with long-standing TED who developed an initially unsuspected orbital or cavernous sinus tumor.

  2. A comparison of different transarterial embolization techniques for direct carotid cavernous fistulas: a single center experience in 32 patients

    PubMed Central

    Lu, Xiaojian; Hussain, Mohammed; Ni, Lanchun; Huang, Qinfeng; Zhou, Fei; Gu, Zhikai; Chen, Jian; Ding, Yuchuan; Xu, Feng

    2014-01-01

    Objective Transarterial treatment of direct carotid cavernous fistulas (DCCF) via embolic materials has been well documented. This study reports, validates, and compares with existing literature our experience treating DCCFs via endovascular approaches by using detachable balloons, coils, and covered stents. Methods Between June 2006 to October 2011, 32 patients (21 male, 11 female) with 32 DCCFs (30 traumatic, 2 spontaneous cavernous ICA aneurysms) were embolized endovascularly. Followup was performed for at least 6 months. Results Among the 32 DCCFs, 21 (65.6%) were embolized using detachable balloons, eight (25.0%) with coils, one (3.1%) with balloons and coils, and two (6.3%) with covered stents. Complete DCCF obliteration was achieved in 31 (96.9%) cases. One fistula failed to respond due to premature balloon detachment. Intracranial bruit in 31 (100%) chemosis and exophthalmos in 28 (100%) cases resolved after embolization. Visual acuity and oculomotor palsy improved in 18 (90%) and 18 (69.2%) cases, respectively. There was no evidence of DCCF recurrence. Thirteen DCCFs were followed up by MRI and five by DSA. In these cases, four (4/13, 30.8%) balloon-embolized DCCFs showed pseudoaneurysms. Three patients were asymptomatic; one had minor left oculomotor palsy. Conclusions Our results correlate and reinforce literature regarding endovascular treatment of DCCFs. Application of Transarterial embolization with detachable balloons, despite extensive use has been decreasing. Coil embolization is an effective and safe alternative for treatment, especially when balloon embolization fails. Covered stent placement may be used as another alternative for selected cases. PMID:25566340

  3. Improvement in Visual Symptomatology after Endovascular Treatment of Cavernous Carotid Aneurysms: A Multicenter Study.

    PubMed

    Drazin, Doniel; Choulakian, Armen; Nuño, Miriam; Gandhi, Ravi; Edgell, Randall C; Alexander, Michael J

    2013-06-01

    Aneurysms arising from the cavernous internal carotid artery (CCAs) pose technical challenges for surgical management and such patients are frequently referred for endovascular treatment. These aneurysms often produce a variety of neurological deficits, primarily those related to oculoparesis. Our purpose was to determine the visual and neurological outcome of patients with treated CCAs. We reviewed the medical records and angiograms for patients who underwent endovascular treatment for CCAs at three academic medical centers. The following outcomes were analyzed: angiographic assessment, visual improvement and outcome at 3 months using Glasgow Outcome Scale (GOS). Thirty-four patients (mean age 54.7 years) were treated for CCAs. The mean aneurysm size was 14.2 mm (range: 3-45 mm), and fourteen patients (41.2%) required stent assistance. Twenty-one aneurysms (61.8%) were completely occluded; nine aneurysms (26.6%) had near-complete occlusion; 4 aneurysms (11.8%) had partial occlusion. Seven patients (20.6%) required retreatment. Fifteen of the 34 patients (44.1%) presented with visual symptoms, while only eight patients had residual visual symptomatology at follow-up (44.1% vs. 23.5%; p=0.02). Patients that presented with visual symptoms (N=15) had a mean aneurysm size of 24.5 mm, while those without visual symptoms (N=19) had a size of 7.5 mm (p=0.001). Follow-up GOS was good (4-5) in 29 patients (90.6%). No thromboembolic complications were observed. One patient died (3.1%) of an unrelated cause. Most patients in this multicenter series improved or remained stable after treatment. The results of this study indicate that endovascular treatment may improve the outcome of visual symptoms in patients with large cavernous aneurysms with low periprocedural morbidity. MJA is a consultant for Stryker and Codman. AC receives a Cordis Endovascular Fellowship Training Grant and a Stryker Endovascular Neurosurgery Post-graduate Fellow Grant. Dr. Drazin: Conception and Design

  4. Study of an orbiting tethered dumbbell system having positive orbital energy

    NASA Technical Reports Server (NTRS)

    Arnold, David A.

    1988-01-01

    For very long tethered systems the sum of the kinetic and potential energy can be positive. The system remains in a circular orbit as long as the masses remain vertically aligned. The system is unstable without constant control of the alignment. If the upper mass rotates forward in the direction of the orbital motion, the system escapes out of orbit. If the upper mass rotates backward, the system falls out of orbit and the lower mass impacts the body around which the system is orbiting.

  5. Orbit-associated tumors: navigation and control of resection using intraoperative computed tomography.

    PubMed

    Terpolilli, Nicole A; Rachinger, Walter; Kunz, Mathias; Thon, Niklas; Flatz, Wilhelm H; Tonn, Jörg-Christian; Schichor, Christian

    2016-05-01

    OBJECT Treatment of skull base lesions is complex and usually requires a multidisciplinary approach. In meningioma, which is the most common tumor entity in this region, resection is considered to be the most important therapeutic step to avoid tumor recurrence. However, resection of skull base lesions with orbital or optic nerve involvement poses a challenge due to their anatomical structure and their proximity to eloquent areas. Therefore the main goal of surgery should be to achieve the maximum extent of resection while preserving neurological function. In the postoperative course, medical and radiotherapeutic strategies may then be successfully used to treat possible tumor residues. Methods to safely improve the extent of resection in skull base lesions therefore are desirable. The current study reports the authors' experience with the use of intraoperative CT (iCT) combined with neuronavigation with regard to feasibility and possible benefits of the method. METHODS Those patients with tumorous lesions in relationship to the orbit, sphenoid wing, or cavernous sinus who were surgically treated between October 2008 and December 2013 using iCT-based neuronavigation and in whom an intraoperative scan was obtained for control of resection were included. In all cases a second iCT scan was performed under sterile conditions after completion of navigation-guided microsurgical tumor resection. The surgical strategy was adapted accordingly; if necessary, resection was continued. RESULTS Twenty-three patients (19 with WHO Grade I meningioma and 4 with other lesions) were included. The most common clinical symptoms were loss of visual acuity and exophthalmus. Intraoperative control of resection by iCT was successfully obtained in all cases. Intraoperative imaging changed the surgical approach in more than half (52.2%) of these patients, either because iCT demonstrated unexpected residual tumor masses or because the second scan revealed additional tumor tissue that was not

  6. Sentinel-2A: Orbit Modelling Improvements and their Impact on the Orbit Prediction

    NASA Astrophysics Data System (ADS)

    Peter, Heike; Otten, Michiel; Fernández Sánchez, Jaime; Fernández Martín, Carlos; Féménias, Pierre

    2016-07-01

    Sentinel-2A is the second satellite of the European Copernicus Programme. The satellite has been launched on 23rd June 2015 and it is operational since mid October 2015. This optical mission carries a GPS receiver for precise orbit determination. The Copernicus POD (Precise Orbit Determination) Service is in charge of generating precise orbital products and auxiliary files for Sentinel-2A as well as for the Sentinel-1 and -3 missions. The accuracy requirements for the Sentinel-2A orbit products are not very stringent with 3 m in 3D (3 sigma) for the near real-time (NRT) orbit and 10 m in 2D (3 sigma) for the predicted orbit. The fulfilment of the orbit accuracy requirements is normally not an issue. The Copernicus POD Service aims, however, to provide the best possible orbits for all three Sentinel missions. Therefore, a sophisticated box-wing model is generated for the Sentinel-2 satellite as it is done for the other two missions as well. Additionally, the solar wing of the satellite is rewound during eclipse, which has to be modelled accordingly. The quality of the orbit prediction is dependent on the results of the orbit estimation performed before it. The values of the last estimation of each parameter is taken for the orbit propagation, i.e. estimating ten atmospheric drag coefficients per 24h, the value of the last coefficient is used as a fix parameter for the subsequent orbit prediction. The question is whether the prediction might be stabilised by, e.g. using an average value of all ten coefficients. This paper presents the status and the quality of the Sentinel-2 orbit determination in the operational environment of the Copernicus POD Service. The impact of the orbit model improvements on the NRT and predicted orbits is studied in detail. Changes in the orbit parametrization as well as in the settings for the orbit propagation are investigated. In addition, the impact of the quality of the input GPS orbit and clock product on the Sentinel-2A orbit

  7. Spin-orbit-torque-induced skyrmion dynamics for different types of spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Jae; Kim, Kyoung-Whan; Lee, Hyun-Woo; Lee, Kyung-Jin

    2018-06-01

    We investigate current-induced skyrmion dynamics in the presence of Dzyaloshinskii-Moriya interaction and spin-orbit spin-transfer torque corresponding to various types of spin-orbit coupling. We determine the symmetries of Dzyaloshinskii-Moriya interaction and spin-orbit spin-transfer torque based on linear spin-orbit coupling model. We find that like interfacial Dzyaloshinskii-Moriya interaction (Rashba spin-orbit coupling) and bulk Dzyaloshinskii-Moriya interaction (Weyl spin-orbit coupling), Dresselhaus spin-orbit coupling also has a possibility for stabilizing skyrmion and current-induced skyrmion dynamics.

  8. A Case of Orbital Abscess following Porous Orbital Implant Infection

    PubMed Central

    Hong, Seung Woo; Paik, Ji-Sun; Kim, So-Youl

    2006-01-01

    Purpose We present a case of orbital abscess following porous orbital implant infection in a 73-year-old woman with rheumatoid arthritis. Methods Just one month after a seemingly uncomplicated enucleation and porous polyethylene (Medpor®) orbital implant surgery, implant exposure developed with profuse pus discharge. The patient was unresponsive to implant removal and MRI confirmed the presence of an orbital pus pocket. Despite extirpation of the four rectus muscles, inflammatory granulation debridement and abscess drainage, another new pus pocket developed. Results After partial orbital exenteration, the wound finally healed well without any additional abscess formation. Conclusions A patient who has risk factors for delayed wound healing must be examined thoroughly and extreme care such as exenteration must be taken if there is persistent infection. PMID:17302210

  9. Lunar Lava Tube Sensing

    NASA Technical Reports Server (NTRS)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  10. Bayesian Orbit Computation Tools for Objects on Geocentric Orbits

    NASA Astrophysics Data System (ADS)

    Virtanen, J.; Granvik, M.; Muinonen, K.; Oszkiewicz, D.

    2013-08-01

    We consider the space-debris orbital inversion problem via the concept of Bayesian inference. The methodology has been put forward for the orbital analysis of solar system small bodies in early 1990's [7] and results in a full solution of the statistical inverse problem given in terms of a posteriori probability density function (PDF) for the orbital parameters. We demonstrate the applicability of our statistical orbital analysis software to Earth orbiting objects, both using well-established Monte Carlo (MC) techniques (for a review, see e.g. [13] as well as recently developed Markov-chain MC (MCMC) techniques (e.g., [9]). In particular, we exploit the novel virtual observation MCMC method [8], which is based on the characterization of the phase-space volume of orbital solutions before the actual MCMC sampling. Our statistical methods and the resulting PDFs immediately enable probabilistic impact predictions to be carried out. Furthermore, this can be readily done also for very sparse data sets and data sets of poor quality - providing that some a priori information on the observational uncertainty is available. For asteroids, impact probabilities with the Earth from the discovery night onwards have been provided, e.g., by [11] and [10], the latter study includes the sampling of the observational-error standard deviation as a random variable.

  11. M1 Macrophages Are Predominantly Recruited to the Major Pelvic Ganglion of the Rat Following Cavernous Nerve Injury.

    PubMed

    Matsui, Hotaka; Sopko, Nikolai A; Hannan, Johanna L; Reinhardt, Allison A; Kates, Max; Yoshida, Takahiro; Liu, Xiaopu; Castiglione, Fabio; Hedlund, Petter; Weyne, Emmanuel; Albersen, Maarten; Bivalacqua, Trinity J

    2017-02-01

    Neurogenic erectile dysfunction is a common sequela of radical prostatectomy. The etiology involves injury to the autonomic cavernous nerves, which arise from the major pelvic ganglion (MPG), and subsequent neuroinflammation, which leads to recruitment of macrophages to the injury site. Currently, two macrophage phenotypes are known: neurotoxic M1 macrophages and neuroprotective M2 macrophages. To examine whether bilateral cavernous nerve injury (BCNI) in a rat model of erectile dysfunction would increase recruitment of neurotoxic M1 macrophages to the MPG. Male Sprague-Dawley rats underwent BCNI and the MPG was harvested at various time points after injury. The corpora cavernosa was used to evaluate tissue myographic responses to electrical field stimulation ex vivo. Quantitative real-time polymerase chain reaction was used to examine the gene expression of global macrophage markers, M1 macrophage markers, M2 macrophage markers, and cytokines and chemokines in the MPG. Mathematical calculation of the M1/M2 index was used to quantify macrophage changes temporally. Western blot of MPG tissues was used to evaluate the protein amount of M1 and M2 macrophage markers quantitatively. Immunohistochemistry staining of MPGs for CD68, CD86, and CD206 was used to characterize M1 and M2 macrophage infiltration. Corpora cavernosa responsiveness ex vivo; gene (quantitative real-time polymerase chain reaction) and protein (western blot) expressions of M1 and M2 markers, cytokines, and chemokines; and immunohistochemical localization of M1 and M2 macrophages. BCNI impaired the corporal parasympathetic-mediated relaxation response to electrical field stimulation and enhanced the contraction response to electrical field stimulation. Gene expression of proinflammatory (Il1b, Il16, Tnfa, Tgfb, Ccl2, Ccr2) and anti-inflammatory (Il10) cytokines was upregulated in the MPG 48 hours after injury. M1 markers (CD86, inducible nitric oxide synthase, interleukin-1β) and M2 markers (CD206

  12. Post-traumatic orbital reconstruction: anatomical landmarks and the concept of the deep orbit.

    PubMed

    Evans, B T; Webb, A A C

    2007-04-01

    Dissection deep within the orbit is a cause for concern to surgeons because of the perceived risks of injuring critical structures such as the contents of the superior orbital fissure and the optic nerve. Although "safe distances" (those distances within which it is considered safe to dissect within the orbit) have been described, these are of limited value if the orbit is severely disrupted or is congenitally shallow. In addition, traumatic defects in the orbital floor, in particular, often extend beyond these distances. Reliable landmarks based on the relations between anatomical structures within the orbit, rather than absolute distances, are described that permit safe dissection within the orbit. We present the concept of the deep orbit and describe its relevance to repair of injuries.

  13. Independent Orbiter Assessment (IOA): Analysis of the orbital maneuvering system

    NASA Technical Reports Server (NTRS)

    Prust, C. D.; Paul, D. J.; Burkemper, V. J.

    1987-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbital Maneuvering System (OMS) hardware are documented. The OMS provides the thrust to perform orbit insertion, orbit circularization, orbit transfer, rendezvous, and deorbit. The OMS is housed in two independent pods located one on each side of the tail and consists of the following subsystems: Helium Pressurization; Propellant Storage and Distribution; Orbital Maneuvering Engine; and Electrical Power Distribution and Control. The IOA analysis process utilized available OMS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluted and analyzed for possible failure modes and effects. Criticality was asigned based upon the severity of the effect for each failure mode.

  14. Orbital endoscopic surgery

    PubMed Central

    Selva, Dinesh

    2008-01-01

    Minimally invasive ″keyhole″ surgery performed using endoscopic visualization is increasing in popularity and is being used by almost all surgical subspecialties. Within ophthalmology, however, endoscopic surgery is not commonly performed and there is little literature on the use of the endoscope in orbital surgery. Transorbital use of the endoscope can greatly aid in visualizing orbital roof lesions and minimizing the need for bone removal. The endoscope is also useful during decompression procedures and as a teaching aid to train orbital surgeons. In this article, we review the history of endoscopic orbital surgery and provide an overview of the technique and describe situations where the endoscope can act as a useful adjunct to orbital surgery. PMID:18158397

  15. Orbiting Rainbows Simulation

    NASA Image and Video Library

    2015-04-22

    This simulated image shows how a cloud of glitter in geostationary orbit would be illuminated and controlled by two laser beams. As the cloud orbits Earth, grains scatter the sun's light at different angles like many tiny prisms, similar to how rainbows are produced from light being dispersed by water droplets. That is why the project concept is called "Orbiting Rainbows." The cloud functions like a reflective surface, allowing the exoplanet (displayed in the bottom right) to be imaged. The orbit path is shown in the top right. On the bottom left, Earth's image is seen behind the cloud. To image an exoplanet, the cloud would need to have a diameter of nearly 98 feet (30 meters). This simulation confines the cloud to a 3.3 x 3.3 x 3.3 foot volume (1 x 1 x 1 meter volume) to simplify the computations. The elements of the orbiting telescope are not to scale. Orbiting Rainbows is currently in Phase II development through the NASA Innovative Advanced Concepts (NIAC) Program. It was one of five technology proposals chosen for continued study in 2014. In the current phase, Orbiting Rainbows researchers are conducting small-scale ground experiments to demonstrate how granular materials can be manipulated using lasers and simulations of how the imaging system would behave in orbit. http://photojournal.jpl.nasa.gov/catalog/PIA19318

  16. Orbital Decompression

    MedlinePlus

    ... A Complications of Sinusitis Epistaxis (Nosebleeds) Allergic Rhinitis (Hay Fever) Headaches and Sinus Disease Disorders of Smell & ... DCR) Disclosure Statement Printer Friendly Orbital Decompression John Lee, MD INTRODUCTION Orbital decompression is a surgical procedure ...

  17. Differentiation between cavernous hemangiomas and untreated malignant neoplasms of the liver with free-breathing diffusion-weighted MR imaging: comparison with T2-weighted fast spin-echo MR imaging.

    PubMed

    Soyer, Philippe; Corno, Lucie; Boudiaf, Mourad; Aout, Mounir; Sirol, Marc; Placé, Vinciane; Duchat, Florent; Guerrache, Youcef; Fargeaudou, Yann; Vicaut, Eric; Pocard, Marc; Hamzi, Lounis

    2011-11-01

    To test interobserver variability of ADC measurements and compare the diagnostic performances of free-breathing diffusion-weighted (FBDW) with that of T2-weighted FSE (T2WFSE) MR imaging for differentiating between cavernous hemangiomas and untreated malignant hepatic neoplasms. Thirty-five patients with cavernous hemangiomas and 35 with untreated hepatic malignant neoplasms had FBDW and T2WFSE MR imaging. Hepatic lesions were characterized with ADC measurement and visual evaluation. Interobserver agreement for ADC measurement was calculated. Association between ADC value and lesion type was assessed using univariate analysis. Sensitivity, specificity and accuracy of ADC values and visual evaluation of MR images for the diagnosis of untreated malignant hepatic neoplasm were compared. ADC measurements showed excellent interobserver correlation (intraclass correlation coefficient=0.980). Malignant neoplasms had lower ADC values than hemangiomas for the two observers (1.11×10(-3) mm2/s±.21×10(-3) vs. 1.77×10(-3) mm2/s±.29×10(-3) for observer 1 and 1.11×10(-3) mm2/s±.19×10(-3) vs. 1.79×10(-3) mm2/s±.32×10(-3) for observer 2) and univariate analysis found significant correlations between lesion type and ADC values. Depending on ADC threshold value, accuracy for the diagnosis of malignant neoplasm varied from 82.9% to 94.3%. Using visual evaluation, FBDW showed better specificity and accuracy than T2WFSE MR images for the diagnosis of malignant neoplasm (97.1% vs. 77.1% and 94.3% vs. 62.9%, respectively). FBDW imaging provides reproducible quantitative information and surpasses the value of T2WFSE MR imaging for differentiating between cavernous hemangiomas and untreated malignant hepatic neoplasms. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. A locus for cerebral cavernous malformations maps to chromosome 7q in two families

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

    Marchuk, D.A.; Gallione, C.J.; Morrison, L.A.

    1995-07-20

    Cavernous malformations (angiomas) affecting the central nervous system and retina can be inherited in autosomal dominant pattern (OMIM 116860). These vascular lesions may remain clinically silent or lead to a number of neurological symptoms including seizure, intracranial hemorrhage, focal neurological deficit, and migraine. We have mapped a gene for this disorder in two families, one of Italian-American origin and one of Mexican-American origin, to markers on proximal 7q, with a combined maximum lod score of 3.92 ({theta} of zero) with marker D7S479. Haplotype analysis of these families places the locus between markers D7S502 proximally and D7S515 distally, an interval ofmore » approximately 41 cM. The location distinguishes this disorder from an autosomal dominant vascular malformation syndrome where lesions are primarily cutaneous and that maps to 9p21. 16 refs., 3 figs., 1 tab.« less

  19. Long-period Seismicity at the Napoleonville Salt Dome: Implications for Local Seismic Monitoring of Underground Hydrocarbon Storage Caverns

    NASA Astrophysics Data System (ADS)

    Dreger, D. S.; Ford, S. R.; Nayak, A.

    2015-12-01

    The formation of a large sinkhole at the Napoleonville salt dome, Assumption Parish, Louisiana, in August 2012 was accompanied by a rich sequence of complex seismic events, including long-period (LP) events that were recorded 11 km away at Transportable Array station 544A in White Castle, Louisiana. The LP events have relatively little energy at short periods, which make them difficult to detect using standard high-frequency power detectors, and the majority of energy that reaches the station is peaked near 0.4 Hz. The analysis of the local records reveals that the onset of the 0.4 Hz signals coincides with the S-wave arrival, and therefore it may be a shaking induced resonance in a fluid filled cavern. We created a low-frequency (0.1-0.6 Hz) power detector (short-term average / long-term average) that operated on all three components of the broadband instrument, since considerable energy was detected on the horizontal components. The detections from the power detector were then used as templates in three-channel correlation detectors thereby increasing the number of detections by a little more than a factor of two to nearly 3000. The rate of LP events is approximately one event every other day at the beginning of recording in March 2011. Around 2 May 2012 the rate changes to approximately 7 events per day and then increases to 25 events per day at the beginning of July 2012. Finally, in the days leading up to the sinkhole formation there are approximately 200 LP events per day. The analysis of these events could aid in the development of local seismic monitoring methods for underground industrial storage caverns. Prepared by LLNL under Contract DE-AC52-07NA27344.

  20. Close up view of the Orbiter Discovery in the Orbiter ...

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

    Close up view of the Orbiter Discovery in the Orbiter Processing Facility at Kennedy Space Center. The view is a detail of the aft, starboard landing gear and a general view of the Thermal Protection System tiles around the landing-gear housing. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  1. Traumatic orbital CSF leak

    PubMed Central

    Borumandi, Farzad

    2013-01-01

    Compared to the cerebrospinalfluid (CSF) leak through the nose and ear, the orbital CSF leak is a rare and underreported condition following head trauma. We present the case of a 49-year-old woman with oedematous eyelid swelling and ecchymosis after a seemingly trivial fall onto the right orbit. Apart from the above, she was clinically unremarkable. The CT scan revealed a minimally displaced fracture of the orbital roof with no emphysema or intracranial bleeding. The fractured orbital roof in combination with the oedematous eyelid swelling raised the suspicion for orbital CSF leak. The MRI of the neurocranium demonstrated a small-sized CSF fistula extending from the anterior cranial fossa to the right orbit. The patient was treated conservatively and the lid swelling resolved completely after 5 days. Although rare, orbital CSF leak needs to be included in the differential diagnosis of periorbital swelling following orbital trauma. PMID:24323381

  2. Orbital debris issues

    NASA Technical Reports Server (NTRS)

    Kessler, D. J.

    1985-01-01

    Man-made orbital debris, identified as a potential hazard to future space activities, is grouped into size categories. At least 79 satellites have broken up in orbit to date and, in combination with exploded rocket casings and antisatellite debris, threaten 10 km/sec collisions with other orbiting platforms. Only 5 percent of the debris is connected to payloads. The total population of orbiting objects over 4 cm in diameter could number as high as 15,000, and at 1 cm in diameter could be 32,000, based on NASA and NORAD studies. NASA has initiated the 10 yr Space Debris Assessment Program to characterize the hazards of orbiting debris, the potential damage to typical spacecraft components, and to identify means of controlling the damage.

  3. Precise orbit determination and rapid orbit recovery supported by time synchronization

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Zhou, JianHua; Hu, XiaoGong; Liu, Li; Tang, Bo; Li, XiaoJie; Wu, Shan

    2015-06-01

    In order to maintain optimal signal coverage, GNSS satellites have to experience orbital maneuvers. For China's COMPASS system, precise orbit determination (POD) as well as rapid orbit recovery after maneuvers contribute to the overall Positioning, Navigation and Timing (PNT) service performance in terms of accuracy and availability. However, strong statistical correlations between clock offsets and the radial component of a satellite's positions require long data arcs for POD to converge. We propose here a new strategy which relies on time synchronization between ground tracking stations and in-orbit satellites. By fixing satellite clock offsets measured by the satellite station two-way synchronization (SSTS) systems and receiver clock offsets, POD and orbital recovery performance can be improved significantly. Using the Satellite Laser Ranging (SLR) as orbital accuracy evaluation, we find the 4-hr recovered orbit achieves about 0.71 m residual root mean square (RMS) error of fit SLR data, the recovery time is improved from 24-hr to 4-hr compared with the conventional POD without time synchronization support. In addition, SLR evaluation shows that for 1-hr prediction, about 1.47 m accuracy is achieved with the new proposed POD strategy.

  4. The Dynamics of Orbit-Clearing for Planets on Eccentric Orbits

    NASA Astrophysics Data System (ADS)

    Hastings, Danielle; Margot, Jean-Luc

    2016-10-01

    The third requirement in the 2006 International Astronomical Union (IAU) definition of a planet is that the object has cleared the neighborhood around its orbit. Margot (2015) proposed a metric that quantitatively determines if an object has enough mass to clear an orbital zone of a specific extent within a defined time interval. In this metric, the size of the zone to be cleared is given by CRH, where C is a constant and RH is the Hill Radius. Margot (2015) adopts C=2*31/2 to describe the minimum extent of orbital clearing on the basis of the planet's feeding zone. However, this value of C may only apply for eccentricities up to about 0.3 (Quillen & Faber 2006). Here, we explore the timescales and boundaries of orbital clearing for planets over a range of orbital eccentricities and planet-star mass ratios using the MERCURY integration package (Chambers 1999). The basic setup for the integrations includes a single planet orbiting a star and a uniform distribution of massless particles extending beyond CRH. The system is integrated for at least 106 revolutions and the massless particles are tracked in order to quantify the timescale and extent of the clearing.

  5. Stent-Assisted Coil Embolization for Cavernous Carotid Artery Aneurysms

    PubMed Central

    KONO, Kenichi; SHINTANI, Aki; OKADA, Hideo; TANAKA, Yuko; TERADA, Tomoaki

    2014-01-01

    Internal carotid artery (ICA) occlusion with or without a bypass surgery is the traditional treatment for cavernous sinus (CS) aneurysms with cranial nerve (CN) dysfunction. Coil embolization without stents frequently requires retreatment because of the large size of CS aneurysms. We report the mid-term results of six unruptured CS aneurysms treated with stent-assisted coil embolization (SACE). The mean age of the patients was 72 years. The mean size of the aneurysms was 19.8 mm (range: 13–26 mm). Before treatment, four patients presented with CN dysfunction and two patients had no symptoms. SACE was performed under local or general anesthesia in three patients each. Mean packing density was 29.1% and tight packing was achieved. There were no neurological complications. CN dysfunction was cured in three patients (75%) and partly resolved in one patient (25%). Transient new CN dysfunction was observed in two patients (33%). Clinical and imaging follow-up ranged from 6 to 26 months (median: 16 months). Recanalization was observed in three patients (50%; neck remnant in two patients and dome filling in one patient), but no retreatment has yet been required. No recurrence of CN dysfunction has occurred yet. In summary, SACE increases packing density and may reduce requirement of retreatment with an acceptable cure rate of CN dysfunction. SACE may be a superior treatment for coiling without stents and be an alternative treatment of ICA occlusion for selected patients, such as older patients and those who require a high-flow bypass surgeryor cannot receive general anesthesia. PMID:24257503

  6. Stent-assisted coil embolization for cavernous carotid artery aneurysms.

    PubMed

    Kono, Kenichi; Shintani, Aki; Okada, Hideo; Tanaka, Yuko; Terada, Tomoaki

    2014-01-01

    Internal carotid artery (ICA) occlusion with or without a bypass surgery is the traditional treatment for cavernous sinus (CS) aneurysms with cranial nerve (CN) dysfunction. Coil embolization without stents frequently requires retreatment because of the large size of CS aneurysms. We report the mid-term results of six unruptured CS aneurysms treated with stent-assisted coil embolization (SACE). The mean age of the patients was 72 years. The mean size of the aneurysms was 19.8 mm (range: 13-26 mm). Before treatment, four patients presented with CN dysfunction and two patients had no symptoms. SACE was performed under local or general anesthesia in three patients each. Mean packing density was 29.1% and tight packing was achieved. There were no neurological complications. CN dysfunction was cured in three patients (75%) and partly resolved in one patient (25%). Transient new CN dysfunction was observed in two patients (33%). Clinical and imaging follow-up ranged from 6 to 26 months (median: 16 months). Recanalization was observed in three patients (50%; neck remnant in two patients and dome filling in one patient), but no retreatment has yet been required. No recurrence of CN dysfunction has occurred yet. In summary, SACE increases packing density and may reduce requirement of retreatment with an acceptable cure rate of CN dysfunction. SACE may be a superior treatment for coiling without stents and be an alternative treatment of ICA occlusion for selected patients, such as older patients and those who require a high-flow bypass surgery or cannot receive general anesthesia.

  7. General view of the Orbiter Discovery in the Orbiter Processing ...

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

    General view of the Orbiter Discovery in the Orbiter Processing Facility at Kennedy Space Center showing the payload bay doors open exposing the heat-dissipating radiator panels located on the inside of the payload bay doors. Also in the view is the boom portion of the boom sensor system deployed as part of the return to flight procedures after STS-107 to inspect the orbiter's thermal protection system. The Remote Manipulator System, the "Canadarm", and the airlock are seen in the background of the image. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  8. Structure and vascular function of MEKK3–cerebral cavernous malformations 2 complex

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

    Fisher, Oriana S.; Deng, Hanqiang; Liu, Dou

    Cerebral cavernous malformations 2 (CCM2) loss is associated with the familial form of CCM disease. The protein kinase MEKK3 (MAP3K3) is essential for embryonic angiogenesis in mice and interacts physically with CCM2, but how this interaction is mediated and its relevance to cerebral vasculature are unknown. Here we report that Mekk3 plays an intrinsic role in embryonic vascular development. Inducible endothelial Mekk3 knockout in neonatal mice is lethal due to multiple intracranial haemorrhages and brain blood vessels leakage. We discover direct interaction between CCM2 harmonin homology domain (HHD) and the N terminus of MEKK3, and determine a 2.35 Å cocrystalmore » structure. We find Mekk3 deficiency impairs neurovascular integrity, which is partially dependent on Rho–ROCK signalling, and that disruption of MEKK3:CCM2 interaction leads to similar neurovascular leakage. We conclude that CCM2:MEKK3-mediated regulation of Rho signalling is required for maintenance of neurovascular integrity, unravelling a mechanism by which CCM2 loss leads to disease.« less

  9. LLOFX earth orbit to lunar orbit delta V estimation program user and technical documentation

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The LLOFX computer program calculates in-plane trajectories from an Earth-orbiting space station to Lunar orbit in such a way that the journey requires only two delta V burns (one to leave Earth circular orbit and one to circularize into Lunar orbit). The program requires the user to supply the Space Station altitude and Lunar orbit altitude (in km above the surface), and the desired time of flight for the transfer (in hours). It then determines and displays the trans-Lunar injection (TLI) delta V required to achieve the transfer, the Lunar orbit insertion (LOI) delta V required to circularize the orbit around the Moon, the actual time of flight, and whether the transfer orbit is elliptical or hyperbolic. Return information is also displayed. Finally, a plot of the transfer orbit is displayed.

  10. Flow diversion in vasculitic intracranial aneurysms? Repair of giant complex cavernous carotid aneurysm in polyarteritis nodosa using Pipeline embolization devices: first reported case.

    PubMed

    Martinez Santos, Jaime; Kaderali, Zul; Spears, Julian; Rubin, Laurence A; Marotta, Thomas R

    2016-07-01

    Intracranial aneurysms in polyarteritis nodosa (PAN) are exceedingly rare lesions with unpredictable behavior that pose real challenges to microsurgical and endovascular interventions owing to their inflammatory nature. We introduce a safe and effective alternative for treating these aneurysms using Pipeline embolization devices (PEDs). A 20-year-old man presented with diplopia, headaches, chronic abdominal pain, and weight loss. Diagnostic evaluations confirmed PAN, including bilateral giant cavernous carotid aneurysms. Cyclophosphamide and steroids achieved significant and sustained clinical improvement, with a decision to follow the aneurysms serially. Seven years later the left unruptured aneurysm enlarged, causing a sudden severe headache and a cavernous sinus syndrome. Treatment of the symptomatic aneurysm was pursued using flow diversion (PED) and the internal carotid artery was successfully reconstructed with a total of four overlapping PEDs. At 6 months follow-up, complete exclusion of the aneurysm was demonstrated, with symptomatic recovery. This is the first description of using a flow-diverting technique in an inflammatory vasculitis. In this case, PEDs not only attained a definitive closure of the aneurysm but also reconstructed the damaged and fragile arterial segment affected with vasculitis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  11. Mars Climate Orbiter

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The purpose of this mission is to study the climate history and the water distribution of Mars. Beautiful panoramic views of the shuttle on the launch pad, engine ignition, Rocket launch, and the separation and burnout of the Solid Rocket Boosters are shown. The footage also includes an animation of the mission. Detailed views of the path that the Orbiter traversed were shown. Once the Orbiter lands on the surface of Mars, it will dig a six to eight inch hole and collect samples from the planets' surface. The animation also included the prospective return of the Orbiter to Earth over the desert of Utah. The remote sensor on the Orbiter helps in finding the exact location of the Orbiter so that scientists may collect the sample and analyze it.

  12. Three Orbital Burns to Molniya Orbit Via Shuttle_Centaur G Upper Stage

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2015-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982 to 1986 joint National Aeronautics and Space Administration (NASA)-United States Air Force (USAF) Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37 deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57 deg inclined orbit: 9,545 versus 9,552 lb of separated spacecraft weight, respectively. There was a significant reduction in the need for propellant launch time reserve for a 1 hr window: only 78 lb for the three burn transfer versus 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three versus two burn transfer (12 vs. 1-1/4 hr), but could be

  13. Three Orbital Burns to Molniya Orbit via Shuttle Centaur G Upper Stage

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2014-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982-86 joint NASA-USAF Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57deg inclined orbit: 9,545 lb vs. 9,552 lb of separated spacecraft weight respectively. There was a significant reduction in the need for propellant launch time reserve for a one hour window: only 78 lb for the three burn transfer vs. 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three vs. two burn transfer (12 vs. 11/4 hrs), but could be accommodated by modest modifications to Centaur systems. Future applications were

  14. Angles-only relative orbit determination in low earth orbit

    NASA Astrophysics Data System (ADS)

    Ardaens, Jean-Sébastien; Gaias, Gabriella

    2018-06-01

    The paper provides an overview of the angles-only relative orbit determination activities conducted to support the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment. This in-orbit endeavor was carried out by the German Space Operations Center (DLR/GSOC) in autumn 2016 to demonstrate the capability to perform spaceborne autonomous close-proximity operations using solely line-of-sight measurements. The images collected onboard have been reprocessed by an independent on-ground facility for precise relative orbit determination, which served as ultimate instance to monitor the formation safety and to characterize the onboard navigation and control performances. During two months, several rendezvous have been executed, generating a valuable collection of images taken at distances ranging from 50 km to only 50 m. Despite challenging experimental conditions characterized by a poor visibility and strong orbit perturbations, angles-only relative positioning products could be continuously derived throughout the whole experiment timeline, promising accuracy at the meter level during the close approaches. The results presented in the paper are complemented with former angles-only experience gained with the PRISMA satellites to better highlight the specificities induced by different orbits and satellite designs.

  15. Family of Orbiters

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image shows the paths of three spacecraft currently in orbit around Mars, as well as the path by which NASA's Phoenix Mars Lander will approach and land on the planet. The t-shaped crosses show where the orbiters will be when Phoenix enters the atmosphere, while the x-shaped crosses show their location at landing time.

    All three orbiters, NASA's Mars Reconnaissance Orbiter, NASA's Mars Odyssey and the European Space Agency's Mars Express, will be monitoring Phoenix during the final steps of its journey to the Red Planet.

    Phoenix will land just south of Mars's north polar ice cap.

  16. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... eye is numbed with medicine (anesthetic drops). The ultrasound wand (transducer) is placed against the front surface ...

  17. Development of Precise Lunar Orbit Propagator and Lunar Polar Orbiter's Lifetime Analysis

    NASA Astrophysics Data System (ADS)

    Song, Young-Joo; Park, Sang-Young; Kim, Hae-Dong; Sim, Eun-Sup

    2010-06-01

    To prepare for a Korean lunar orbiter mission, a precise lunar orbit propagator; Yonsei precise lunar orbit propagator (YSPLOP) is developed. In the propagator, accelerations due to the Moon's non-spherical gravity, the point masses of the Earth, Moon, Sun, Mars, Jupiter and also, solar radiation pressures can be included. The developed propagator's performance is validated and propagation errors between YSPOLP and STK/Astrogator are found to have about maximum 4-m, in along-track direction during 30 days (Earth's time) of propagation. Also, it is found that the lifetime of a lunar polar orbiter is strongly affected by the different degrees and orders of the lunar gravity model, by a third body's gravitational attractions (especially the Earth), and by the different orbital inclinations. The reliable lifetime of circular lunar polar orbiter at about 100 km altitude is estimated to have about 160 days (Earth's time). However, to estimate the reasonable lifetime of circular lunar polar orbiter at about 100 km altitude, it is strongly recommended to consider at least 50 × 50 degrees and orders of the lunar gravity field. The results provided in this paper are expected to make further progress in the design fields of Korea's lunar orbiter missions.

  18. Mars Telecommunications Orbiter, Artist's Concept

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This illustration depicts a concept for NASA's Mars Telecommunications Orbiter in flight around Mars. The orbiter is in development to be the first spacecraft with a primary function of providing communication links while orbiting a foreign planet. The project's plans call for launch in September 2009, arrival at Mars in August 2010 and a mission of six to 10 years while in orbit. Mars Telecommunication Orbiter would serve as the Mars hub for an interplanetery Internet, greatly increasing the information payoff from other future Mars missions. The mission is designed to orbit Mars more than 10 times farther from the planet than orbiters dedicated primarily to science. The high-orbit design minimizes the time that Mars itself blocks the orbiter from communicating with Earth and maximizes the time that the orbiter is above the horizon -- thus capable of communications relay -- for rovers and stationary landers on Mars' surface.

  19. Space station orbit maintenance

    NASA Technical Reports Server (NTRS)

    Kaplan, D. I.; Jones, R. M.

    1983-01-01

    The orbit maintenance problem is examined for two low-earth-orbiting space station concepts - the large, manned Space Operations Center (SOC) and the smaller, unmanned Science and Applications Space Platform (SASP). Atmospheric drag forces are calculated, and circular orbit altitudes are selected to assure a 90 day decay period in the event of catastrophic propulsion system failure. Several thrusting strategies for orbit maintenance are discussed. Various chemical and electric propulsion systems for orbit maintenance are compared on the basis of propellant resupply requirements, power requirements, Shuttle launch costs, and technology readiness.

  20. Contralateral Supracerebellar-Infratentorial Approach for Resection of Thalamic Cavernous Malformations.

    PubMed

    Mascitelli, Justin; Burkhardt, Jan-Karl; Gandhi, Sirin; Lawton, Michael T

    2018-02-26

    Surgical resection of cavernous malformations (CM) in the posterior thalamus, pineal region, and midbrain tectum is technically challenging owing to the presence of adjacent eloquent cortex and critical neurovascular structures. Various supracerebellar infratentorial (SCIT) approaches have been used in the surgical armamentarium targeting lesions in this region, including the median, paramedian, and extreme lateral variants. Surgical view of a posterior thalamic CM from the traditional ipsilateral vantage point may be obscured by occipital lobe and tentorium. To describe a novel surgical approach via a contralateral SCIT (cSCIT) trajectory for resecting posterior thalamic CMs. From 1997 to 2017, 75 patients underwent the SCIT approach for cerebrovascular/oncologic pathology by the senior author. Of these, 30 patients underwent the SCIT approach for CM resection, and 3 patients underwent the cSCIT approach. Historical patient data, radiographic features, surgical technique, and postoperative neurological outcomes were evaluated in each patient. All 3 patients presented with symptomatic CMs within the right posterior thalamus with radiographic evidence of hemorrhage. All surgeries were performed in the sitting position. There were no intraoperative complications. Neuroimaging demonstrated complete CM resection in all cases. There were no new or worsening neurological deficits or evidence of rebleeding/recurrence noted postoperatively. This study establishes the surgical feasibility of a contralateral SCIT approach in resection of symptomatic thalamic CMs It demonstrates the application for this procedure in extending the surgical trajectory superiorly and laterally and maximizing safe resectability of these deep CMs with gravity-assisted brain retraction.

  1. Orbit error characteristic and distribution of TLE using CHAMP orbit data

    NASA Astrophysics Data System (ADS)

    Xu, Xiao-li; Xiong, Yong-qing

    2018-02-01

    Space object orbital covariance data is required for collision risk assessments, but publicly accessible two line element (TLE) data does not provide orbital error information. This paper compared historical TLE data and GPS precision ephemerides of CHAMP to assess TLE orbit accuracy from 2002 to 2008, inclusive. TLE error spatial variations with longitude and latitude were calculated to analyze error characteristics and distribution. The results indicate that TLE orbit data are systematically biased from the limited SGP4 model. The biases can reach the level of kilometers, and the sign and magnitude are correlate significantly with longitude.

  2. Burn Delay Analysis of the Lunar Orbit Insertion for Korea Pathfinder Lunar Orbiter

    NASA Astrophysics Data System (ADS)

    Bae, Jonghee; Song, Young-Joo; Kim, Young-Rok; Kim, Bangyeop

    2017-12-01

    The first Korea lunar orbiter, Korea Pathfinder Lunar Orbiter (KPLO), has been in development since 2016. After launch, the KPLO will execute several maneuvers to enter into the lunar mission orbit, and will then perform lunar science missions for one year. Among these maneuvers, the lunar orbit insertion (LOI) is the most critical maneuver because the KPLO will experience an extreme velocity change in the presence of the Moon’s gravitational pull. However, the lunar orbiter may have a delayed LOI burn during operation due to hardware limitations and telemetry delays. This delayed burn could occur in different captured lunar orbits; in the worst case, the KPLO could fly away from the Moon. Therefore, in this study, the burn delay for the first LOI maneuver is analyzed to successfully enter the desired lunar orbit. Numerical simulations are performed to evaluate the difference between the desired and delayed lunar orbits due to a burn delay in the LOI maneuver. Based on this analysis, critical factors in the LOI maneuver, the periselene altitude and orbit period, are significantly changed and an additional delta-V in the second LOI maneuver is required as the delay burn interval increases to 10 min from the planned maneuver epoch.

  3. Diverse Orbits Around Mars Graphic

    NASA Image and Video Library

    2015-05-04

    This graphic depicts the relative shapes and distances from Mars for five active orbiter missions plus the planet's two natural satellites. It illustrates the potential for intersections of the spacecraft orbits. The number of active orbiter missions at Mars increased from three to five in 2014. With the increased traffic, NASA has augmented a process for anticipating orbit intersections and avoiding collisions. NASA's Mars Odyssey and MRO (Mars Reconnaissance Orbiter) travel near-circular orbits. The European Space Agency's Mars Express, NASA's MAVEN (Mars Atmosphere and Volatile Evolution) and India's MOM (Mars Orbiter Mission), travel more elliptical orbits. Phobos and Deimos are the two natural moons of Mars. http://photojournal.jpl.nasa.gov/catalog/PIA19396

  4. The Solar Poynting-Robertson Effect On Particles Orbiting Solar System Bodies: Circular Orbits

    NASA Technical Reports Server (NTRS)

    Rubincam, David P.

    2013-01-01

    The Poynting-Robertson effect from sunlight impinging directly on a particle which orbits a Solar System body (planet, asteroid, comet) is considered from the Sun's rest frame. There appear to be no significant first-order terms in V(sub b)/c for circular orbits, where V(sub b) is the body's speed in its orbit about the Sun and c is the speed of light, when the particle's orbital semimajor axis is much smaller than the body's orbital semimajor axis about the Sun as is mainly the case in the Solar System.

  5. Dynamic contrast-enhanced MRI evaluation of cerebral cavernous malformations.

    PubMed

    Hart, Blaine L; Taheri, Saeid; Rosenberg, Gary A; Morrison, Leslie A

    2013-10-01

    The aim of this study is to quantitatively evaluate the behavior of CNS cavernous malformations (CCMs) using a dynamic contrast-enhanced MRI (DCEMRI) technique sensitive for slow transfer rates of gadolinium. The prospective study was approved by the institutional review board and was HIPPA compliant. Written informed consent was obtained from 14 subjects with familial CCMs (4 men and 10 women, ages 22-76 years, mean 48.1 years). Following routine anatomic MRI of the brain, DCEMRI was performed for six slices, using T1 mapping with partial inversion recovery (TAPIR) to calculate T1 values, following administration of 0.025 mmol/kg gadolinium DTPA. The transfer rate (Ki) was calculated using the Patlak model, and Ki within CCMs was compared to normal-appearing white matter as well as to 17 normal control subjects previously studied. All subjects had typical MRI appearance of CCMs. Thirty-nine CCMs were studied using DCEMRI. Ki was low or normal in 12 lesions and elevated from 1.4 to 12 times higher than background in the remaining 27 lesions. Ki ranged from 2.1E-6 to 9.63E-4 min(-1), mean 3.55E-4. Normal-appearing white matter in the CCM patients had a mean Ki of 1.57E-4, not statistically different from mean WM Ki of 1.47E-4 in controls. TAPIR-based DCEMRI technique permits quantifiable assessment of CCMs in vivo and reveals considerable differences not seen with conventional MRI. Potential applications include correlation with biologic behavior such as lesion growth or hemorrage, and measurement of drug effects.

  6. Dynamic Contrast-Enhanced MRI Evaluation of Cerebral Cavernous Malformations

    PubMed Central

    Hart, B. L.; Taheri, S.; Rosenberg, G. A.; Morrison, L. A.

    2013-01-01

    The aim of this study is to quantitatively evaluate the behavior of CNS cavernous malformations (CCMs) using a dynamic contrast-enhanced MRI (DCEMRI) technique sensitive for slow transfer rates of gadolinium. The prospective study was approved by the institutional review board and was HIPPA compliant. Written informed consent was obtained from 14 subjects with familial CCMs (4 men and 10 women, ages 22–76 years, mean 48.1 years). Following routine anatomic MRI of the brain, DCEMRI was performed for six slices, using T1 mapping with partial inversion recovery (TAPIR) to calculate T1 values, following administration of 0.025 mmol/kg gadolinium DTPA. The transfer rate (Ki) was calculated using the Patlak model, and Ki within CCMs was compared to normal-appearing white matter as well as to 17 normal control subjects previously studied. All subjects had typical MRI appearance of CCMs. Thirty-nine CCMs were studied using DCEMRI. Ki was low or normal in 12 lesions and elevated from 1.4 to 12 times higher than background in the remaining 27 lesions. Ki ranged from 2.1E–6 to 9.63E–4 min−1, mean 3.55E–4. Normal-appearing white matter in the CCM patients had a mean Ki of 1.57E–4, not statistically different from mean WM Ki of 1.47E–4 in controls. TAPIR-based DCEMRI technique permits quantifiable assessment of CCMs in vivo and reveals considerable differences not seen with conventional MRI. Potential applications include correlation with biologic behavior such as lesion growth or hemorrage, and measurement of drug effects. PMID:24323376

  7. Low-Cost 3D Printing Orbital Implant Templates in Secondary Orbital Reconstructions.

    PubMed

    Callahan, Alison B; Campbell, Ashley A; Petris, Carisa; Kazim, Michael

    Despite its increasing use in craniofacial reconstructions, three-dimensional (3D) printing of customized orbital implants has not been widely adopted. Limitations include the cost of 3D printers able to print in a biocompatible material suitable for implantation in the orbit and the breadth of available implant materials. The authors report the technique of low-cost 3D printing of orbital implant templates used in complex, often secondary, orbital reconstructions. A retrospective case series of 5 orbital reconstructions utilizing a technique of 3D printed orbital implant templates is presented. Each patient's Digital Imaging and Communications in Medicine data were uploaded and processed to create 3D renderings upon which a customized implant was designed and sent electronically to printers open for student use at our affiliated institutions. The mock implants were sterilized and used intraoperatively as a stencil and mold. The final implant material was chosen by the surgeons based on the requirements of the case. Five orbital reconstructions were performed with this technique: 3 tumor reconstructions and 2 orbital fractures. Four of the 5 cases were secondary reconstructions. Molded Medpor Titan (Stryker, Kalamazoo, MI) implants were used in 4 cases and titanium mesh in 1 case. The stenciled and molded implants were adjusted no more than 2 times before anchored in place (mean 1). No case underwent further revision. The technique and cases presented demonstrate 1) the feasibility and accessibility of low-cost, independent use of 3D printing technology to fashion patient-specific implants in orbital reconstructions, 2) the ability to apply this technology to the surgeon's preference of any routinely implantable material, and 3) the utility of this technique in complex, secondary reconstructions.

  8. Stable low-altitude orbits around Ganymede considering a disturbing body in a circular orbit

    NASA Astrophysics Data System (ADS)

    Cardoso dos Santos, J.; Carvalho, J. P. S.; Vilhena de Moraes, R.

    2014-10-01

    Some missions are being planned to visit Ganymede like the Europa Jupiter System Mission that is a cooperation between NASA and ESA to insert the spacecraft JGO (Jupiter Ganymede Orbiter) into Ganymedes orbit. This comprehension of the dynamics of these orbits around this planetary satellite is essential for the success of this type of mission. Thus, this work aims to perform a search for low-altitude orbits around Ganymede. An emphasis is given in polar orbits and it can be useful in the planning of space missions to be conducted around, with respect to the stability of orbits of artificial satellites. The study considers orbits of artificial satellites around Ganymede under the influence of the third-body (Jupiter's gravitational attraction) and the polygenic perturbations like those due to non-uniform distribution of mass (J_2 and J_3) of the main body. A simplified dynamic model for these perturbations is used. The Lagrange planetary equations are used to describe the orbital motion of the artificial satellite. The equations of motion are developed in closed form to avoid expansions in eccentricity and inclination. The results show the argument of pericenter circulating. However, low-altitude (100 and 150 km) polar orbits are stable. Another orbital elements behaved variating with small amplitudes. Thus, such orbits are convenient to be applied to future space missions to Ganymede. Acknowledgments: FAPESP (processes n° 2011/05671-5, 2012/12539-9 and 2012/21023-6).

  9. Geographically correlated orbit error

    NASA Technical Reports Server (NTRS)

    Rosborough, G. W.

    1989-01-01

    The dominant error source in estimating the orbital position of a satellite from ground based tracking data is the modeling of the Earth's gravity field. The resulting orbit error due to gravity field model errors are predominantly long wavelength in nature. This results in an orbit error signature that is strongly correlated over distances on the size of ocean basins. Anderle and Hoskin (1977) have shown that the orbit error along a given ground track also is correlated to some degree with the orbit error along adjacent ground tracks. This cross track correlation is verified here and is found to be significant out to nearly 1000 kilometers in the case of TOPEX/POSEIDON when using the GEM-T1 gravity model. Finally, it was determined that even the orbit error at points where ascending and descending ground traces cross is somewhat correlated. The implication of these various correlations is that the orbit error due to gravity error is geographically correlated. Such correlations have direct implications when using altimetry to recover oceanographic signals.

  10. Spin-orbit torques from interfacial spin-orbit coupling for various interfaces

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung-Whan; Lee, Kyung-Jin; Sinova, Jairo; Lee, Hyun-Woo; Stiles, M. D.

    2017-09-01

    We use a perturbative approach to study the effects of interfacial spin-orbit coupling in magnetic multilayers by treating the two-dimensional Rashba model in a fully three-dimensional description of electron transport near an interface. This formalism provides a compact analytic expression for current-induced spin-orbit torques in terms of unperturbed scattering coefficients, allowing computation of spin-orbit torques for various contexts, by simply substituting scattering coefficients into the formulas. It applies to calculations of spin-orbit torques for magnetic bilayers with bulk magnetism, those with interface magnetism, a normal-metal/ferromagnetic insulator junction, and a topological insulator/ferromagnet junction. It predicts a dampinglike component of spin-orbit torque that is distinct from any intrinsic contribution or those that arise from particular spin relaxation mechanisms. We discuss the effects of proximity-induced magnetism and insertion of an additional layer and provide formulas for in-plane current, which is induced by a perpendicular bias, anisotropic magnetoresistance, and spin memory loss in the same formalism.

  11. Spin-orbit torques from interfacial spin-orbit coupling for various interfaces.

    PubMed

    Kim, Kyoung-Whan; Lee, Kyung-Jin; Sinova, Jairo; Lee, Hyun-Woo; Stiles, M D

    2017-09-01

    We use a perturbative approach to study the effects of interfacial spin-orbit coupling in magnetic multilayers by treating the two-dimensional Rashba model in a fully three-dimensional description of electron transport near an interface. This formalism provides a compact analytic expression for current-induced spin-orbit torques in terms of unperturbed scattering coefficients, allowing computation of spin-orbit torques for various contexts, by simply substituting scattering coefficients into the formulas. It applies to calculations of spin-orbit torques for magnetic bilayers with bulk magnetism, those with interface magnetism, a normal metal/ferromagnetic insulator junction, and a topological insulator/ferromagnet junction. It predicts a dampinglike component of spin-orbit torque that is distinct from any intrinsic contribution or those that arise from particular spin relaxation mechanisms. We discuss the effects of proximity-induced magnetism and insertion of an additional layer and provide formulas for in-plane current, which is induced by a perpendicular bias, anisotropic magnetoresistance, and spin memory loss in the same formalism.

  12. Spin-orbit torques from interfacial spin-orbit coupling for various interfaces

    PubMed Central

    Kim, Kyoung-Whan; Lee, Kyung-Jin; Sinova, Jairo; Lee, Hyun-Woo; Stiles, M. D.

    2017-01-01

    We use a perturbative approach to study the effects of interfacial spin-orbit coupling in magnetic multilayers by treating the two-dimensional Rashba model in a fully three-dimensional description of electron transport near an interface. This formalism provides a compact analytic expression for current-induced spin-orbit torques in terms of unperturbed scattering coefficients, allowing computation of spin-orbit torques for various contexts, by simply substituting scattering coefficients into the formulas. It applies to calculations of spin-orbit torques for magnetic bilayers with bulk magnetism, those with interface magnetism, a normal metal/ferromagnetic insulator junction, and a topological insulator/ferromagnet junction. It predicts a dampinglike component of spin-orbit torque that is distinct from any intrinsic contribution or those that arise from particular spin relaxation mechanisms. We discuss the effects of proximity-induced magnetism and insertion of an additional layer and provide formulas for in-plane current, which is induced by a perpendicular bias, anisotropic magnetoresistance, and spin memory loss in the same formalism. PMID:29333523

  13. Orbit-attitude coupled motion around small bodies: Sun-synchronous orbits with Sun-tracking attitude motion

    NASA Astrophysics Data System (ADS)

    Kikuchi, Shota; Howell, Kathleen C.; Tsuda, Yuichi; Kawaguchi, Jun'ichiro

    2017-11-01

    The motion of a spacecraft in proximity to a small body is significantly perturbed due to its irregular gravity field and solar radiation pressure. In such a strongly perturbed environment, the coupling effect of the orbital and attitude motions exerts a large influence that cannot be neglected. However, natural orbit-attitude coupled dynamics around small bodies that are stationary in both orbital and attitude motions have yet to be observed. The present study therefore investigates natural coupled motion that involves both a Sun-synchronous orbit and Sun-tracking attitude motion. This orbit-attitude coupled motion enables a spacecraft to maintain its orbital geometry and attitude state with respect to the Sun without requiring active control. Therefore, the proposed method can reduce the use of an orbit and attitude control system. This paper first presents analytical conditions to achieve Sun-synchronous orbits and Sun-tracking attitude motion. These analytical solutions are then numerically propagated based on non-linear coupled orbit-attitude equations of motion. Consequently, the possibility of implementing Sun-synchronous orbits with Sun-tracking attitude motion is demonstrated.

  14. Diagrammatic theory of transition of pendulum like systems. [orbit-orbit and spin-orbit gravitational resonance interactions

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.

    1979-01-01

    Orbit-orbit and spin-orbit gravitational resonances are analyzed using the model of a rigid pendulum subject to both a time-dependent periodic torque and a constant applied torque. First, a descriptive model of passage through resonance is developed from an examination of the polynomial equation that determines the extremes of the momentum variable. From this study, a probability estimate for capture into libration is derived. Second, a lowest order solution is constructed and compared with the solution obtained from numerical integration. The steps necessary to systematically improve this solution are also discussed. Finally, the effect of a dissipative term in the pendulum equation is analyzed.

  15. [Orbito-palpebral vascular pathology].

    PubMed

    Heran Dreyfus, F; Galatoire, O; Koskas, P; Lafitte, F; Nau, E; Bergès, O

    2016-11-01

    Orbito-palpebral vascular pathology represents 10% of all the diseases of this area. The lesion may be discovered during a brain CT scan or MRI, or because it causes clinical symptoms such as orbital mass, visual or oculomotor alteration, pain, proptosis, or acute bleeding due to a complication of the lesion (hemorrhage, thrombosis). We present these lesions using an anatomical, clinical, imaging and therapeutic approach. We distinguish four different entities. Vascular tumors have common imaging characteristics (hypersignal on T2 sequence, contrast enhancement, abnormal vascularization well depicted with ultrasound and Doppler, and possible bleeding). The main lesions are cavernous hemangiomas, the most frequent lesion of that type during adulthood; infantile hemangiomas, the most frequent vascular tumor in children; and more seldomly, hemangioperitcytomas. True vascular malformations are divided according to their flow. Low flow lesions are venous (orbital varix), capillarovenous or lymphatic (lymphangioma). High flow malformations, more rare, are either arteriovenous or arterial malformations (aneurisms). Complex malformations include both low and high flow elements. Lesions leading to modifications of the orbito-palpebral blood flow are mainly due to cavernous sinus abnormalities, either direct carotid-cavernous fistula affecting young adults after severe head trauma, or dural fistula, more insidious, found in older adults. The last section is devoted to congenital syndromic vascular malformations (Sturge-Weber, Rendu-Olser…). This classification allows for a better understanding of these pathologies and their specific imaging features. Copyright © 2016. Published by Elsevier Masson SAS.

  16. Gaussian-Type Orbitals versus Slater-Type Orbitals: A Comparison

    ERIC Educational Resources Information Center

    Magalha~es, Alexandre L.

    2014-01-01

    The advantages of Gaussian-type orbitals (GTO) over Slater-type orbitals (STO) in quantum chemistry calculations are clarified here by means of a holistic approach. The popular Microsoft Office Excel program was used to create an interactive application with which students are able to explore the features of GTO, including automatic calculations…

  17. The keys to successful TIPS in patients with portal vein thrombosis and cavernous transformation.

    PubMed

    Lombardo, S; Espejo, J J; Pérez-Montilla, M E; Zurera, L J; González-Galilea, Á

    Portal vein thrombosis is a common complication in patients with cirrhosis. Anticoagulation involves a high risk of bleeding secondary to portal hypertension, so placing transjugular intrahepatic portosystemic shunts (TIPS) has become an alternative treatment for portal vein thrombosis. Three strategies for TIPS placement have been reported: 1) portal recanalization and conventional implantation of the TIPS through the jugular vein; 2) portal recanalization through percutaneous transhepatic/transsplenic) access; and (3) insertion of the TIPS between the suprahepatic vein and a periportal collateral vessel without portal recanalization. We describe different materials that can be used as fluoroscopic targets for the TIPS needle and for portal recanalization. This article aims to show the success of TIPS implantation using different combinations of the techniques listed above, which is a good treatment alternative in these patients whose clinical condition makes them difficult to manage, and to show that portal vein thrombosis/cavernous transformation should not be considered a contraindication for TIPS. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Galileo Jupiter approach orbit determination

    NASA Technical Reports Server (NTRS)

    Miller, J. K.; Nicholson, F. T.

    1984-01-01

    Orbit determination characteristics of the Jupiter approach phase of the Galileo mission are described. Predicted orbit determination performance is given for the various mission events that occur during Jupiter approach. These mission events include delivery of an atmospheric entry probe, acquisition of probe science data by the Galileo orbiter for relay to earth, delivery of an orbiter to a close encounter of the Galilean satellite Io, and insertion of the orbiter into orbit about Jupiter. The orbit determination strategy and resulting accuracies are discussed for the data types which include Doppler, range, optical imaging of Io, and a new Very Long Baseline Interferometry (VLBI) data type called Differential One-Way Range (DOR).

  19. Design of an unmanned, reusable vehicle to de-orbit debris in Earth orbit

    NASA Technical Reports Server (NTRS)

    Aziz, Shahed; Cunningham, Timothy W.; Moore-Mccassey, Michelle

    1990-01-01

    The space debris problem is becoming more important because as orbital missions increase, the amount of debris increases. It was the design team's objective to present alternative designs and a problem solution for a deorbiting vehicle that will alleviate the problem by reducing the amount of large debris in earth orbit. The design team was asked to design a reusable, unmanned vehicle to de-orbit debris in earth orbit. The design team will also construct a model to demonstrate the system configuration and key operating features. The alternative designs for the unmanned, reusable vehicle were developed in three stages: selection of project requirements and success criteria, formulation of a specification list, and the creation of alternatives that would satisfy the standards set forth by the design team and their sponsor. The design team selected a Chain and Bar Shot method for deorbiting debris in earth orbit. The De-orbiting Vehicle (DOV) uses the NASA Orbital Maneuvering Vehicle (OMV) as the propulsion and command modules with the deorbiting module attached to the front.

  20. Applicability of meteor radiant determination methods depending on orbit type. II. Low-eccentric orbits

    NASA Astrophysics Data System (ADS)

    Svoren, J.; Neslusan, L.; Porubcan, V.

    1994-08-01

    All known parent bodies of meteor showers belong to bodies moving in high-eccentricity orbits (e => 0.5). Recently, asteroids in low-eccentricity orbits (e < 0.5) approaching the Earth's orbit, were suggested as another population of possible parent bodies of meteor streams. This paper deals with the problem of calculation of meteor radiants connected with the bodies in low-eccentricity orbits from the point of view of optimal results depending on the method applied. The paper is a continuation of our previous analysis of high-eccentricity orbits (Svoren, J., Neslusan, L., Porubcan, V.: 1993, Contrib. Astron. Obs. Skalnate Pleso 23, 23). Some additional methods resulting from mathematical modelling are presented and discussed together with Porter's, Steel-Baggaley's and Hasegawa's methods. In order to be able to compare how suitable the application of the individual radiant determination methods is, it is necessary to determine the accuracy with which they approximate real meteor orbits. To verify the accuracy with which the orbit of a meteoroid with at least one node at 1 AU fits the original orbit of the parent body, the Southworth-Hawkins D-criterion (Southworth, R.B., Hawkins, G.S.: 1963, Smithson. Contr. Astrophys. 7, 261) was applied. D <= 0.1 indicates a very good fit of orbits, 0.1 < D <= 0.2 is considered for a good fit and D > 0.2 means that the fit is rather poor and the change of orbit unrealistic. The optimal method, i.e. the one which results in the smallest D values for the population of low-eccentricity orbits, is that of adjusting the orbit by varying both the eccentricity and perihelion distance. A comparison of theoretical radiants obtained by various methods was made for typical representatives from each group of the NEA (near-Earth asteroids) objects.

  1. Sedna Orbit Comparisons

    NASA Technical Reports Server (NTRS)

    2004-01-01

    These four panels show the location of the newly discovered planet-like object, dubbed 'Sedna,' which lies in the farthest reaches of our solar system. Each panel, moving counterclockwise from the upper left, successively zooms out to place Sedna in context. The first panel shows the orbits of the inner planets, including Earth, and the asteroid belt that lies between Mars and Jupiter. In the second panel, Sedna is shown well outside the orbits of the outer planets and the more distant Kuiper Belt objects. Sedna's full orbit is illustrated in the third panel along with the object's current location. Sedna is nearing its closest approach to the Sun; its 10,000 year orbit typically takes it to far greater distances. The final panel zooms out much farther, showing that even this large elliptical orbit falls inside what was previously thought to be the inner edge of the Oort cloud. The Oort cloud is a spherical distribution of cold, icy bodies lying at the limits of the Sun's gravitational pull. Sedna's presence suggests that this Oort cloud is much closer than scientists believed.

  2. Orbit Alignment in Triple Stars

    NASA Astrophysics Data System (ADS)

    Tokovinin, Andrei

    2017-08-01

    The statistics of the angle Φ between orbital angular momenta in hierarchical triple systems with known inner visual or astrometric orbits are studied. A correlation between apparent revolution directions proves the partial orbit alignment known from earlier works. The alignment is strong in triples with outer projected separation less than ˜50 au, where the average Φ is about 20^\\circ . In contrast, outer orbits wider than 1000 au are not aligned with the inner orbits. It is established that the orbit alignment decreases with the increasing mass of the primary component. The average eccentricity of inner orbits in well-aligned triples is smaller than in randomly aligned ones. These findings highlight the role of dissipative interactions with gas in defining the orbital architecture of low-mass triple systems. On the other hand, chaotic dynamics apparently played a role in shaping more massive hierarchies. The analysis of projected configurations and triples with known inner and outer orbits indicates that the distribution of Φ is likely bimodal, where 80% of triples have {{Φ }}< 70^\\circ and the remaining ones are randomly aligned.

  3. New osculating orbits for 110 comets and analysis of original orbits for 200 comets

    NASA Technical Reports Server (NTRS)

    Marsden, B. G.; Sekanina, Z.; Everhart, E.

    1978-01-01

    Osculating orbits are presented for 110 nearly parabolic comets. Combining these with selected orbit determinations from other sources, a total of 200 orbits are considered where the available observations yield a result of very good (first-class) or good (second-class) quality. For each of these, the original and future orbits (referred to the barycenter of the solar system) are calculated. The Oort effect (a tendency for original reciprocal semimajor axis values to range from zero to +100 millionths per AU) is clearly seen among the first-class orbits but not among the second-class orbits. Modifications in original reciprocal semimajor axis values due to the effects of nongravitational forces are considered.

  4. Icariside II Promotes the Differentiation of Adipose Tissue-Derived Stem Cells to Schwann Cells to Preserve Erectile Function after Cavernous Nerve Injury.

    PubMed

    Zheng, Tao; Zhang, Tian-Biao; Wang, Chao-Liang; Zhang, Wei-Xing; Jia, Dong-Hui; Yang, Fan; Sun, Yang-Yang; Ding, Xiao-Ju; Wang, Rui

    2018-06-14

    Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual- Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs' proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by upregulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II promotes the differentiation of ADSCs to SCs through the miR- 34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.

  5. Preliminary orbital parallax catalog

    NASA Technical Reports Server (NTRS)

    Halliwell, M.

    1981-01-01

    The study is undertaken to calibrate the more reliable parallaxes derived from a comparison of visual and spectroscopic orbits and to encourage observational studies of other promising binaries. The methodological techniques used in computing orbital parallaxes are analyzed. Tables summarizing orbital data and derived system properties are then given. Also given is a series of detailed discussions of the 71 individual systems included in the tables. Data are listed for 57 other systems which are considered promising candidates for eventual orbital parallax determination.

  6. Five Equivalent d Orbitals

    ERIC Educational Resources Information Center

    Pauling, Linus; McClure, Vance

    1970-01-01

    Amplifies and clarifies a previous paper on pyramidal d orbitals. Discusses two sets of pyramid d orbitals with respect to their maximum bond strength and their symmetry. Authors described the oblate and prolate pentagonal antiprisms arising from the two sets of five equivalent d orbitals. (RR)

  7. Orbital relaxation effects on Kohn–Sham frontier orbital energies in density functional theory

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

    Zhang, DaDi; Zheng, Xiao, E-mail: xz58@ustc.edu.cn; Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026

    2015-04-21

    We explore effects of orbital relaxation on Kohn–Sham frontier orbital energies in density functional theory by using a nonempirical scaling correction approach developed in Zheng et al. [J. Chem. Phys. 138, 174105 (2013)]. Relaxation of Kohn–Sham orbitals upon addition/removal of a fractional number of electrons to/from a finite system is determined by a systematic perturbative treatment. The information of orbital relaxation is then used to improve the accuracy of predicted Kohn–Sham frontier orbital energies by Hartree–Fock, local density approximation, and generalized gradient approximation methods. The results clearly highlight the significance of capturing the orbital relaxation effects. Moreover, the proposed scalingmore » correction approach provides a useful way of computing derivative gaps and Fukui quantities of N-electron finite systems (N is an integer), without the need to perform self-consistent-field calculations for (N ± 1)-electron systems.« less

  8. Marned Orbital Systems Concept

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Despite the indefinite postponement of the Space Station in 1972, Marshall Space Flight Center (MSFC) continued to look to the future for some type of orbital facility during the post-Skylab years. In 1975, the MSFC directed a contract with the McDonnel Douglas Aerospace Company for the Manned Orbital Systems Concept (MOSC) study. This 9-month effort examined the requirements for, and defined a cost-effective orbital facility concept capable of, supporting extended manned missions in Earth orbit. The capabilities of this concept exceeded those envisioned for the Space Shuttle and Spacelab, both of which were limited by a 7 to 30-day orbital time constraint. The MOSC's initial operating capability was to be achieved in late 1984. A crew of four would man a four-module configuration. During its five-year orbital life the MOSC would have the capability to evolve into a larger 12-to-24-man facility. This is an artist's concept of MOSC.

  9. Observing orbital debris using space-based telescopes. I - Mission orbit considerations

    NASA Technical Reports Server (NTRS)

    Reynolds, Robert C.; Talent, David L.; Vilas, Faith

    1989-01-01

    In this paper, mission orbit considerations are addressed for using the Space Shuttle as a telescope platform for observing man-made orbital debris. Computer modeling of various electrooptical systems predicts that such a space-borne system will be able to detect particles as small as 1-mm diameter. The research is meant to support the development of debris- collision warning sensors through the acquisition of spatial distribution and spectral characteristics for debris and testing of detector combinations on a shuttle-borne telescopic experiment. The technique can also be applied to low-earth-orbit-debris environment monitoring systems. It is shown how the choice of mission orbit, season of launch, and time of day of launch may be employed to provide extended periods of favorable observing conditions.

  10. Orbital-2 Mission

    NASA Image and Video Library

    2014-07-11

    The Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft onboard, is seen on launch Pad-0A, Friday, July 11, 2014, at NASA's Wallops Flight Facility in Virginia. The Antares will launch with the Cygnus spacecraft filled with over 3,000 pounds of supplies for the International Space Station, including science experiments, experiment hardware, spare parts, and crew provisions. The Orbital-2 mission is Orbital Sciences' second contracted cargo delivery flight to the space station for NASA. Photo Credit: (NASA/Bill Ingalls)

  11. Orbital-2 Mission

    NASA Image and Video Library

    2014-07-12

    The Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft onboard, is seen, Saturday, July 12, 2014, at launch Pad-0A of NASA's Wallops Flight Facility in Virginia. The Antares will launch with the Cygnus spacecraft filled with over 3,000 pounds of supplies for the International Space Station, including science experiments, experiment hardware, spare parts, and crew provisions. The Orbital-2 mission is Orbital Sciences' second contracted cargo delivery flight to the space station for NASA. Photo Credit: (NASA/Bill Ingalls)

  12. Neonatal orbital abscess

    PubMed Central

    Al-Salem, Khalil M; Alsarayra, Fawaz A; Somkawar, Areej R

    2014-01-01

    Orbital complications due to ethmoiditis are rare in neonates. A case of orbital abscess due to acute ethmoiditis in a 28-day-old girl is presented. A Successful outcome was achieved following antimicrobial therapy alone; spontaneous drainage of the abscess occurred from the lower lid without the need for surgery. From this case report, we intend to emphasize on eyelid retraction as a sign of neonatal orbital abscess, and to review all the available literature of similar cases. PMID:24008806

  13. Comment on “Reconciliation of the Devils Hole climate record with orbital forcing”

    USGS Publications Warehouse

    Winograd, Isaac J.

    2016-01-01

    Moseley et al. (Reports, 8 January 2016, p. 165) postulate an increase in dissolved thorium isotope 230Th with depth below the water table as the explanation for the differing ages of Termination II. Flow of geothermal water through the Devils Hole caverns precludes this explanation. Deposition of younger secondary calcite into the initial porosity of the calcite comprising their cores is a plausible alternate explanation.

  14. Comment on “Reconciliation of the Devils Hole climate record with orbital forcing”

    NASA Astrophysics Data System (ADS)

    Winograd, Isaac J.

    2016-10-01

    Moseley et al. (Reports, 8 January 2016, p. 165) postulate an increase in dissolved thorium isotope 230Th with depth below the water table as the explanation for the differing ages of Termination II. Flow of geothermal water through the Devils Hole caverns precludes this explanation. Deposition of younger secondary calcite into the initial porosity of the calcite comprising their cores is a plausible alternate explanation.

  15. Hypersonic aerodynamic characteristics of NR-ATP orbiter, orbiter with external tank, and ascent configuration

    NASA Technical Reports Server (NTRS)

    Ashby, G. C., Jr.

    1973-01-01

    A scale model of the North American Rockwell ATP Orbiter with and without the external tank has been tested in a 22-inch helium tunnel at Mach 20 and a Reynolds number based on model length, of 2.14 times one million. Longitudinal and lateral-directional data were determined for the orbiter alone while only longitudinal characteristics and elevon roll effectiveness were investigated for the orbiter/tank combination. Oil flow and electron beam flow visualization studies were conducted for the orbiter alone, orbiter with external tank and the ascent configuration.

  16. Surgical Management and Long-Term Seizure Outcome After Surgery for Temporal Lobe Epilepsy Associated with Cerebral Cavernous Malformations.

    PubMed

    Yang, Peng-Fan; Pei, Jia-Sheng; Jia, Yan-Zeng; Lin, Qiao; Xiao, Hui; Zhang, Ting-Ting; Zhong, Zhong-Hui

    2018-02-01

    Operative strategies for cerebral cavernous malformation (CCM)-associated temporal lobe epilepsy and timing of surgical intervention continue to be debated. This study aimed to establish an algorithm to evaluate the efficacy of surgical intervention strategies, to maximize positive surgical outcomes and minimize postsurgical neurologic deficits. 47 patients having undergone operation for CCM-associated temporal lobe epilepsy were retrospectively reviewed. They had received a diagnostic series for seizure localization, including long-term video electroencephalography (vEEG), high-resolution magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT). In patients with mesial temporal lobe CCMs, the involved structures (amygdala, hippocampus, or parahippocampal gyrus) were resected in addition to the lesions. Patients with neocortical epileptogenic CCM underwent extended lesionectomy guided by intraoperative electrocorticography; further performance of amygdalohippocampectomy depended on the extent of hippocampal epileptogenicity. The study cohort contained 28 patients with drug-resistant epilepsy (DRE), 12 with chronic epilepsy (CE), and 7 with sporadic seizure (SS). Normal temporal lobe metabolism was seen in 7/7 patients of the SS group. Hypometabolism was found in all patients with chronic disease except for those with posterior inferior and middle temporal gyrus cavernous malformations (CMs). Of the 31 patients with superficial neocortical CCM, 7 had normal PET without hippocampal sclerosis, 14 had ipsilateral temporal lobe hypometabolism without hippocampal sclerosis, and 10 had obvious hippocampal sclerosis and hypometabolism. Seizure freedom in DRE, CE, and SS was 82.1%, 75%, and 100%, respectively. A significant difference was found between lesion laterality and postoperative seizure control; the rate was lower in left-sided cases because of less aggressive resection. Our study demonstrates that the data from the

  17. Small incision iris tumour biopsy using a cavernous sampling forceps.

    PubMed

    Chronopoulos, Argyrios; Kilic, Ergin; Joussen, Antonia M; Lipski, Andreas

    2014-11-01

    The aim of this retrospective report is to describe our experience with the Essen-23G biopsy forceps (Akgül forceps) for biopsies of pigmented iris tumours. In this retrospective study of cases between October 2012 and September 2013, patients with iris tumours and clinical signs for malignancy underwent biopsy to secure the diagnosis. The Essen-23G-forceps was used to grasp and extract tissue through a clear corneal incision. Eventual entry and bimanual manipulation with a 23G mini-scissors was achieved through a second incision. Tissue samples were fixed in a sterile tube for further histopathological and immunohistochemical evaluation. Seven eyes of seven patients underwent biopsy using the forceps. The average thickness of the iris tumours was 1.07±0.79 mm. A second corneal incision for scissoring in a bimanual technique was necessary in 5 cases (71%). In 6 cases (85%), a precise histological and immunohistochemical diagnosis was achieved. Complications were limited to minute bleeding at the biopsy site and one case of relative pupil enlargement (anisocoria) without further refractive issues. Iris tumour biopsies can be successfully approached using a cavernous 23G intraocular forceps with a low risk for procedure-related complications. The conical interior design allows for removal of whole tissue pieces with minimal manipulative artefacts. An optional bimanual access through a second corneal incision and use of a 23G scissors provides better efficacy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Precise orbit determination of the Lunar Reconnaissance Orbiter and first gravity field results

    NASA Astrophysics Data System (ADS)

    Maier, Andrea; Baur, Oliver

    2014-05-01

    The Lunar Reconnaissance Orbiter (LRO) was launched in 2009 and is expected to orbit the Moon until the end of 2014. Among other instruments, LRO has a highly precise altimeter on board demanding an orbit accuracy of one meter in the radial component. Precise orbit determination (POD) is achieved with radiometric observations (Doppler range rates, ranges) on the one hand, and optical laser ranges on the other hand. LRO is the first satellite at a distance of approximately 360 000 to 400 000 km from the Earth that is routinely tracked with optical laser ranges. This measurement type was introduced to achieve orbits of higher precision than it would be possible with radiometric observations only. In this contribution we investigate the strength of each measurement type (radiometric range rates, radiometric ranges, optical laser ranges) based on single-technique orbit estimation. In a next step all measurement types are combined in a joined analysis. In addition to POD results, preliminary gravity field coefficients are presented being a subsequent product of the orbit determination process. POD and gravity field estimation was accomplished with the NASA/GSFC software packages GEODYN and SOLVE.

  19. Orbital Debris: A Policy Perspective

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2007-01-01

    A viewgraph presentation describing orbital debris from a policy perspective is shown. The contents include: 1) Voyage through near-Earth Space-animation; 2) What is Orbital Debris?; 3) Orbital Debris Detectors and Damage Potential; 4) Hubble Space Telescope; 5) Mir Space Station Solar Array; 6) International Space Station; 7) Space Shuttle; 8) Satellite Explosions; 9) Satellite Collisions; 10) NASA Orbital Debris Mitigation Guidelines; 11) International Space Station Jettison Policy; 12) Controlled/Uncontrolled Satellite Reentries; 13) Return of Space Objects; 14) Orbital Debris and U.S. National Space Policy; 15) U.S Government Policy Strategy; 16) Bankruptcy of the Iridium Satellite System; 17) Inter-Agency Space Debris Coordination Committee (IADC); 18) Orbital Debris at the United Nations; 19) Chinese Anti-satellite System; 20) Future Evolution of Satellite Population; and 21) Challenge of Orbital Debris

  20. Maintaining Aura's Orbit Requirements While Performing Orbit Maintenance Maneuvers Containing an Orbit Normal Delta-V Component

    NASA Technical Reports Server (NTRS)

    Johnson, Megan R.; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Aura's Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Aura's frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under noslew operations.

  1. Familial Cerebral Cavernous Malformations Are Associated with Adrenal Calcifications on CT Scans: An Imaging Biomarker for a Hereditary Cerebrovascular Condition.

    PubMed

    Strickland, Corinne D; Eberhardt, Steven C; Bartlett, Mary R; Nelson, Jeffrey; Kim, Helen; Morrison, Leslie A; Hart, Blaine L

    2017-08-01

    Purpose To determine if adrenal calcifications seen at computed tomography (CT) are associated with familial cerebral cavernous malformations (fCCMs) in carriers of the CCM1 Common Hispanic Mutation. Materials and Methods This study was approved by the institutional review board. The authors retrospectively reviewed abdominal CT scans in 38 patients with fCCM, 38 unaffected age- and sex-matched control subjects, and 13 patients with sporadic, nonfamilial cerebral cavernous malformation (CCM). The size, number, and laterality of calcifications and the morphologic characteristics of the adrenal gland were recorded. Brain lesion count was recorded from brain magnetic resonance (MR) imaging in patients with fCCM. The prevalence of adrenal calcifications in patients with fCCM was compared with that in unaffected control subjects and those with sporadic CCM by using the Fisher exact test. Additional analyses were performed to determine whether age and brain lesion count were associated with adrenal findings in patients with fCCM. Results Small focal calcifications (SFCs) (≤5 mm) were seen in one or both adrenal glands in 19 of the 38 patients with fCCM (50%), compared with 0 of the 38 unaffected control subjects (P < .001) and 0 of the 13 subjects with sporadic CCM (P = .001). Adrenal calcifications in patients with fCCM were more frequently left sided, with 17 of 19 patients having more SFCs in the left adrenal gland than the right adrenal gland and 50 of the 61 observed SFCs (82%) found in the left adrenal gland. No subjects had SFCs on the right side only. In patients with fCCM, the presence of SFCs showed a positive correlation with age (P < .001) and number of brain lesions (P < .001). Conclusion Adrenal calcifications identified on CT scans are common in patients with fCCM and may be a clinically silent manifestation of disease. © RSNA, 2017.

  2. Precise orbits of the Lunar Reconnaissance Orbiter from radiometric tracking data

    NASA Astrophysics Data System (ADS)

    Löcher, Anno; Kusche, Jürgen

    2018-02-01

    Since 2009, the Lunar Reconnaissance Orbiter (LRO) acquires images and altimetric profiles of the lunar surface. Assembling these data to maps and terrain models requires the precise knowledge of the spacecraft trajectory. In this contribution, we present 5 years of LRO orbits from radiometric data processed with a software tailored to this mission. The presented orbits are the first independent validation of the LRO science orbits from NASA and are available for public use. A key feature of our processing is the elaborate treatment of model and observation errors by empirical parameters and an adaptive data weighting by variance component estimation. The quality of the resulting orbits is assessed by analyzing overlapping arcs. For our solution based on arcs of 2.5 days, such analysis yields a mean error of 2.81 m in total position and 0.11 m in radial direction. It is shown that this result greatly benefits from the adaptive data weighting, reducing the error by 2.54 and 0.13 m, respectively. Unfortunately, the precision achieved varies strongly, dependent on the view onto the orbital ellipse which changes with the lunar cycle. To mitigate this dependency, the arc length was extended in steps up to 10.5 days, leading in the best case to a further improvement of 0.80 m.

  3. Update on orbital reconstruction.

    PubMed

    Chen, Chien-Tzung; Chen, Yu-Ray

    2010-08-01

    Orbital trauma is common and frequently complicated by ocular injuries. The recent literature on orbital fracture is analyzed with emphasis on epidemiological data assessment, surgical timing, method of approach and reconstruction materials. Computed tomographic (CT) scan has become a routine evaluation tool for orbital trauma, and mobile CT can be applied intraoperatively if necessary. Concomitant serious ocular injury should be carefully evaluated preoperatively. Patients presenting with nonresolving oculocardiac reflex, 'white-eyed' blowout fracture, or diplopia with a positive forced duction test and CT evidence of orbital tissue entrapment require early surgical repair. Otherwise, enophthalmos can be corrected by late surgery with a similar outcome to early surgery. The use of an endoscope-assisted approach for orbital reconstruction continues to grow, offering an alternative method. Advances in alloplastic materials have improved surgical outcome and shortened operating time. In this review of modern orbital reconstruction, several controversial issues such as surgical indication, surgical timing, method of approach and choice of reconstruction material are discussed. Preoperative fine-cut CT image and thorough ophthalmologic examination are key elements to determine surgical indications. The choice of surgical approach and reconstruction materials much depends on the surgeon's experience and the reconstruction area. Prefabricated alloplastic implants together with image software and stereolithographic models are significant advances that help to more accurately reconstruct the traumatized orbit. The recent evolution of orbit reconstruction improves functional and aesthetic results and minimizes surgical complications.

  4. Classification of orbital morphology for decompression surgery in Graves' orbitopathy: two-dimensional versus three-dimensional orbital parameters.

    PubMed

    Borumandi, Farzad; Hammer, Beat; Noser, Hansrudi; Kamer, Lukas

    2013-05-01

    Three-dimensional (3D) CT reconstruction of the bony orbit for accurate measurement and classification of the complex orbital morphology may not be suitable for daily practice. We present an easily measurable two-dimensional (2D) reference dataset of the bony orbit for study of individual orbital morphology prior to decompression surgery in Graves' orbitopathy. CT images of 70 European adults (140 orbits) with unaffected orbits were included. On axial views, the following orbital dimensions were assessed: orbital length (OL), globe length (GL), GL/OL ratio and cone angle. Postprocessed CT data were required to measure the corresponding 3D orbital parameters. The 2D and 3D orbital parameters were correlated. The 2D orbital parameters were significantly correlated to the corresponding 3D parameters (significant at the 0.01 level). The average GL was 25 mm (SD±1.0), the average OL was 42 mm (SD±2.0) and the average GL/OL ratio was 0.6 (SD±0.03). The posterior cone angle was, on average, 50.2° (SD±4.1). Three orbital sizes were classified: short (OL≤40 mm), medium (OL>40 to <45 mm) and large (OL≥45 mm). We present easily measurable reference data for the orbit that can be used for preoperative study and classification of individual orbital morphology. A short and shallow orbit may require a different decompression technique than a large and deep orbit. Prospective clinical trials are needed to demonstrate how individual orbital morphology affects the outcome of decompression surgery.

  5. Orbital-2 Mission

    NASA Image and Video Library

    2014-07-12

    The full Moon sets in the fog behind the Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft onboard, Saturday, July 12, 2014, launch Pad-0A, NASA's Wallops Flight Facility in Virginia. The Antares will launch with the Cygnus spacecraft filled with over 3,000 pounds of supplies for the International Space Station, including science experiments, experiment hardware, spare parts, and crew provisions. The Orbital-2 mission is Orbital Sciences' second contracted cargo delivery flight to the space station for NASA. Photo Credit: (NASA/Bill Ingalls)

  6. Orbital-2 Mission

    NASA Image and Video Library

    2014-07-12

    The Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft onboard, is seen during sunrise, Saturday, July 12, 2014, at launch Pad-0A of NASA's Wallops Flight Facility in Virginia. The Antares will launch with the Cygnus spacecraft filled with over 3,000 pounds of supplies for the International Space Station, including science experiments, experiment hardware, spare parts, and crew provisions. The Orbital-2 mission is Orbital Sciences' second contracted cargo delivery flight to the space station for NASA. Photo Credit: (NASA/Bill Ingalls)

  7. Satellite laser ranging to low Earth orbiters: orbit and network validation

    NASA Astrophysics Data System (ADS)

    Arnold, Daniel; Montenbruck, Oliver; Hackel, Stefan; Sośnica, Krzysztof

    2018-04-01

    Satellite laser ranging (SLR) to low Earth orbiters (LEOs) provides optical distance measurements with mm-to-cm-level precision. SLR residuals, i.e., differences between measured and modeled ranges, serve as a common figure of merit for the quality assessment of orbits derived by radiometric tracking techniques. We discuss relevant processing standards for the modeling of SLR observations and highlight the importance of line-of-sight-dependent range corrections for the various types of laser retroreflector arrays. A 1-3 cm consistency of SLR observations and GPS-based precise orbits is demonstrated for a wide range of past and present LEO missions supported by the International Laser Ranging Service (ILRS). A parameter estimation approach is presented to investigate systematic orbit errors and it is shown that SLR validation of LEO satellites is not only able to detect radial but also along-track and cross-track offsets. SLR residual statistics clearly depend on the employed precise orbit determination technique (kinematic vs. reduced-dynamic, float vs. fixed ambiguities) but also reveal pronounced differences in the ILRS station performance. Using the residual-based parameter estimation approach, corrections to ILRS station coordinates, range biases, and timing offsets are derived. As a result, root-mean-square residuals of 5-10 mm have been achieved over a 1-year data arc in 2016 using observations from a subset of high-performance stations and ambiguity-fixed orbits of four LEO missions. As a final contribution, we demonstrate that SLR can not only validate single-satellite orbit solutions but also precise baseline solutions of formation flying missions such as GRACE, TanDEM-X, and Swarm.

  8. Orbital Debris: A Chronology

    NASA Technical Reports Server (NTRS)

    Portree, Davis S. F. (Editor); Loftus, Joseph P., Jr. (Editor)

    1999-01-01

    This chronology covers the 37-year history of orbital debris concerns. It tracks orbital debris hazard creation, research, observation, experimentation, management, mitigation, protection, and policy. Included are debris-producing, events; U.N. orbital debris treaties, Space Shuttle and space station orbital debris issues; ASAT tests; milestones in theory and modeling; uncontrolled reentries; detection system development; shielding development; geosynchronous debris issues, including reboost policies: returned surfaces studies, seminar papers reports, conferences, and studies; the increasing effect of space activities on astronomy; and growing international awareness of the near-Earth environment.

  9. The Mars Reconnaissance Orbiter Mission: 10 Years of Exploration from Mars Orbit

    NASA Technical Reports Server (NTRS)

    Johnston, M. Daniel; Zurek, Richard W.

    2016-01-01

    The Mars Reconnaissance Orbiter ( MRO ) entered Mars orbit on March 10, 2006. After five months of aerobraking, a series of propulsive maneuvers were used to establish the desired low -altitude science orbit. The spacecraft has been on station in its 255 x 320 k m, sun -synchronous (approximately 3 am -pm ), primary science orbit since September 2006 performing both scientific and Mars programmatic support functions. This paper will provide a summary of the major achievements of the mission to date and the major flight activities planned for the remainder of its third Extended Mission (EM3). Some of the major flight challenges the flight team has faced are also discussed.

  10. Sedna Orbit Comparisons

    NASA Image and Video Library

    2004-03-15

    These four panels show the location of the newly discovered planet-like object, dubbed "Sedna," which lies in the farthest reaches of our solar system. Each panel, moving counterclockwise from the upper left, successively zooms out to place Sedna in context. The first panel shows the orbits of the inner planets, including Earth, and the asteroid belt that lies between Mars and Jupiter. In the second panel, Sedna is shown well outside the orbits of the outer planets and the more distant Kuiper Belt objects. Sedna's full orbit is illustrated in the third panel along with the object's current location. Sedna is nearing its closest approach to the Sun; its 10,000 year orbit typically takes it to far greater distances. The final panel zooms out much farther, showing that even this large elliptical orbit falls inside what was previously thought to be the inner edge of the Oort cloud. The Oort cloud is a spherical distribution of cold, icy bodies lying at the limits of the Sun's gravitational pull. Sedna's presence suggests that this Oort cloud is much closer than scientists believed. http://photojournal.jpl.nasa.gov/catalog/PIA05569

  11. Orbiter entry aerothermodynamics

    NASA Technical Reports Server (NTRS)

    Ried, R. C.

    1985-01-01

    The challenge in the definition of the entry aerothermodynamic environment arising from the challenge of a reliable and reusable Orbiter is reviewed in light of the existing technology. Select problems pertinent to the orbiter development are discussed with reference to comprehensive treatments. These problems include boundary layer transition, leeward-side heating, shock/shock interaction scaling, tile gap heating, and nonequilibrium effects such as surface catalysis. Sample measurements obtained from test flights of the Orbiter are presented with comparison to preflight expectations. Numerical and wind tunnel simulations gave efficient information for defining the entry environment and an adequate level of preflight confidence. The high quality flight data provide an opportunity to refine the operational capability of the orbiter and serve as a benchmark both for the development of aerothermodynamic technology and for use in meeting future entry heating challenges.

  12. Ionospheric refraction effects on orbit determination using the orbit determination error analysis system

    NASA Technical Reports Server (NTRS)

    Yee, C. P.; Kelbel, D. A.; Lee, T.; Dunham, J. B.; Mistretta, G. D.

    1990-01-01

    The influence of ionospheric refraction on orbit determination was studied through the use of the Orbit Determination Error Analysis System (ODEAS). The results of a study of the orbital state estimate errors due to the ionospheric refraction corrections, particularly for measurements involving spacecraft-to-spacecraft tracking links, are presented. In current operational practice at the Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF), the ionospheric refraction effects on the tracking measurements are modeled in the Goddard Trajectory Determination System (GTDS) using the Bent ionospheric model. While GTDS has the capability of incorporating the ionospheric refraction effects for measurements involving ground-to-spacecraft tracking links, such as those generated by the Ground Spaceflight Tracking and Data Network (GSTDN), it does not have the capability to incorporate the refraction effects for spacecraft-to-spacecraft tracking links for measurements generated by the Tracking and Data Relay Satellite System (TDRSS). The lack of this particular capability in GTDS raised some concern about the achievable accuracy of the estimated orbit for certain classes of spacecraft missions that require high-precision orbits. Using an enhanced research version of GTDS, some efforts have already been made to assess the importance of the spacecraft-to-spacecraft ionospheric refraction corrections in an orbit determination process. While these studies were performed using simulated data or real tracking data in definitive orbit determination modes, the study results presented here were obtained by means of covariance analysis simulating the weighted least-squares method used in orbit determination.

  13. Validation of Galileo orbits using SLR with a focus on satellites launched into incorrect orbital planes

    NASA Astrophysics Data System (ADS)

    Sośnica, Krzysztof; Prange, Lars; Kaźmierski, Kamil; Bury, Grzegorz; Drożdżewski, Mateusz; Zajdel, Radosław; Hadas, Tomasz

    2018-02-01

    The space segment of the European Global Navigation Satellite System (GNSS) Galileo consists of In-Orbit Validation (IOV) and Full Operational Capability (FOC) spacecraft. The first pair of FOC satellites was launched into an incorrect, highly eccentric orbital plane with a lower than nominal inclination angle. All Galileo satellites are equipped with satellite laser ranging (SLR) retroreflectors which allow, for example, for the assessment of the orbit quality or for the SLR-GNSS co-location in space. The number of SLR observations to Galileo satellites has been continuously increasing thanks to a series of intensive campaigns devoted to SLR tracking of GNSS satellites initiated by the International Laser Ranging Service. This paper assesses systematic effects and quality of Galileo orbits using SLR data with a main focus on Galileo satellites launched into incorrect orbits. We compare the SLR observations with respect to microwave-based Galileo orbits generated by the Center for Orbit Determination in Europe (CODE) in the framework of the International GNSS Service Multi-GNSS Experiment for the period 2014.0-2016.5. We analyze the SLR signature effect, which is characterized by the dependency of SLR residuals with respect to various incidence angles of laser beams for stations equipped with single-photon and multi-photon detectors. Surprisingly, the CODE orbit quality of satellites in the incorrect orbital planes is not worse than that of nominal FOC and IOV orbits. The RMS of SLR residuals is even lower by 5.0 and 1.5 mm for satellites in the incorrect orbital planes than for FOC and IOV satellites, respectively. The mean SLR offsets equal -44.9, -35.0, and -22.4 mm for IOV, FOC, and satellites in the incorrect orbital plane. Finally, we found that the empirical orbit models, which were originally designed for precise orbit determination of GNSS satellites in circular orbits, provide fully appropriate results also for highly eccentric orbits with variable linear

  14. Feasibility and tradeoff study of an aeromaneuvering orbit-to-orbit shuttle (AMOOS)

    NASA Technical Reports Server (NTRS)

    White, J.

    1974-01-01

    This study establishes that configurations satisfying the aeromaneuvering orbit-to-orbit shuttle (AMOOS) requirements can be designed with performance capabilities in excess of the purely propulsive space tug. In view of this improved potential of the AMOOS vehicle over the propulsive space tug concept it is recommended that the AMOOS studies be advanced to a stage comparable to those performed for the space tug. This advancement is needed in particular in areas that are either peculiar to AMOOS or not addressed in sufficient detail in these studies to date. These areas include the thermodynamics problems, navigation and guidance, operations and economics analyses, subsystems and interfaces. The aeromaneuvering orbit-to-orbit shuttle (AMOOS) is evaluated as a candidate reusable third stage to the two-stage earth-to-orbit shuttle (EOS). AMOOS has the potential for increased payload capability over the purely propulsive space tug by trading a savings in consumables for an increase in structural and thermal protection system (TPS) mass.

  15. Introducing Earth's Orbital Eccentricity

    ERIC Educational Resources Information Center

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  16. Do Close-in Giant Planets Orbiting Evolved Stars Prefer Eccentric Orbits?

    NASA Astrophysics Data System (ADS)

    Grunblatt, Samuel K.; Huber, Daniel; Gaidos, Eric; Lopez, Eric D.; Barclay, Thomas; Chontos, Ashley; Sinukoff, Evan; Van Eylen, Vincent; Howard, Andrew W.; Isaacson, Howard T.

    2018-07-01

    The NASA Kepler and K2 Missions have recently revealed a population of transiting giant planets orbiting moderately evolved, low-luminosity red giant branch stars. Here, we present radial velocity (RV) measurements of three of these systems, revealing significantly non-zero orbital eccentricities in each case. Comparing these systems with the known planet population suggests that close-in giant planets around evolved stars tend to have more eccentric orbits than those around main sequence stars. We interpret this as tentative evidence that the orbits of these planets pass through a transient, moderately eccentric phase where they shrink faster than they circularize due to tides raised on evolved host stars. Additional RV measurements of currently known systems, along with new systems discovered by the recently launched NASA Transiting Exoplanet Survey Satellite (TESS) mission, may constrain the timescale and mass dependence of this process.

  17. Sinus involvement in inflammatory orbital pseudotumor.

    PubMed

    Eshaghian, J; Anderson, R L

    1981-04-01

    Orbital pseudotumor is a difficult diagnosis to establish preoperatively. The relationship between sinus disease and orbital pseudotumor is controversial. We describe two patients with unilateral proptosis, diplopia, palpable orbital masses, ocular discomfort, and sinus problems of short duration. Echographically, both had low reflective masses in the orbit and the adjacent sinuses. Roentgenograms and echograms were interpreted as showing erosion of the bony orbital wall. A presumptive diagnosis of sinus malignant neoplasm with orbital extension was made. Sinus histopathologic examination in one case and nasal histopathologic examination in the other showed chronic inflammatory changes compatible with the diagnosis of pseudotumor. At orbitotomy, one patient had vessels communicating between the orbital and sinus lesions, and both patients had irregular pitting of the bone next to the histologically proved orbital pseudotumors. The lytic erosive changes predicted preoperatively were not present. Simultaneous orbital and sinus pseudotumors seem to be a distinct clinicopathologic entity. Those concerned with the diagnosis and management of orbital disease should be aware of this entity.

  18. Correlation of nonorthogonality of best hybrid bond orbitals with bond strength of orthogonal orbitals.

    PubMed

    Pauling, L

    1976-02-01

    An expression is derived for the bond length of two spd orbitals with maximum values in two directions forming a given bond angle by consideration of the nonorthogonality integral of two best orbitals in these directions. This equation is equivalent to the expression derived by formulating the pair of orthogonal orbitals. Similar expressions are derived for spdf orbitals. Applications are made to icosahedral and cuboctahedral bonds and to the packing of nucleons in atomic nuclei.

  19. Congenital orbital teratoma.

    PubMed

    Aiyub, Shereen; Chan, Wengonn; Szetu, John; Sullivan, Laurence J; Pater, John; Cooper, Peter; Selva, Dinesh

    2013-12-01

    We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma.

  20. Congenital orbital teratoma

    PubMed Central

    Aiyub, Shereen; Chan, Weng Onn; Szetu, John; Sullivan, Laurence J; Pater, John; Cooper, Peter; Selva, Dinesh

    2013-01-01

    We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma. PMID:23619505

  1. Orbit Determination of Spacecraft in Earth-Moon L1 and L2 Libration Point Orbits

    NASA Technical Reports Server (NTRS)

    Woodard, Mark; Cosgrove, Daniel; Morinelli, Patrick; Marchese, Jeff; Owens, Brandon; Folta, David

    2011-01-01

    The ARTEMIS mission, part of the THEMIS extended mission, is the first to fly spacecraft in the Earth-Moon Lissajous regions. In 2009, two of the five THEMIS spacecraft were redeployed from Earth-centered orbits to arrive in Earth-Moon Lissajous orbits in late 2010. Starting in August 2010, the ARTEMIS P1 spacecraft executed numerous stationkeeping maneuvers, initially maintaining a lunar L2 Lissajous orbit before transitioning into a lunar L1 orbit. The ARTEMIS P2 spacecraft entered a L1 Lissajous orbit in October 2010. In April 2011, both ARTEMIS spacecraft will suspend Lissajous stationkeeping and will be maneuvered into lunar orbits. The success of the ARTEMIS mission has allowed the science team to gather unprecedented magnetospheric measurements in the lunar Lissajous regions. In order to effectively perform lunar Lissajous stationkeeping maneuvers, the ARTEMIS operations team has provided orbit determination solutions with typical accuracies on the order of 0.1 km in position and 0.1 cm/s in velocity. The ARTEMIS team utilizes the Goddard Trajectory Determination System (GTDS), using a batch least squares method, to process range and Doppler tracking measurements from the NASA Deep Space Network (DSN), Berkeley Ground Station (BGS), Merritt Island (MILA) station, and United Space Network (USN). The team has also investigated processing of the same tracking data measurements using the Orbit Determination Tool Kit (ODTK) software, which uses an extended Kalman filter and recursive smoother to estimate the orbit. The orbit determination results from each of these methods will be presented and we will discuss the advantages and disadvantages associated with using each method in the lunar Lissajous regions. Orbit determination accuracy is dependent on both the quality and quantity of tracking measurements, fidelity of the orbit force models, and the estimation techniques used. Prior to Lissajous operations, the team determined the appropriate quantity of tracking

  2. Correlation of nonorthogonality of best hybrid bond orbitals with bond strength of orthogonal orbitals

    PubMed Central

    Pauling, Linus

    1976-01-01

    An expression is derived for the bond length of two spd orbitals with maximum values in two directions forming a given bond angle by consideration of the nonorthogonality integral of two best orbitals in these directions. This equation is equivalent to the expression derived by formulating the pair of orthogonal orbitals. Similar expressions are derived for spdf orbitals. Applications are made to icosahedral and cuboctahedral bonds and to the packing of nucleons in atomic nuclei. PMID:16578736

  3. Orbit Maintenance and Navigation of Human Spacecraft at Cislunar Near Rectilinear Halo Orbits

    NASA Technical Reports Server (NTRS)

    Davis, Diane; Bhatt, Sagar; Howell, Kathleen; Jang, Jiann-Woei; Whitley, Ryan; Clark, Fred; Guzzetti, Davide; Zimovan, Emily; Barton, Gregg

    2017-01-01

    Multiple studies have concluded that Earth-Moon libration point orbits are attractive candidates for staging operations. The Near Rectilinear Halo Orbit (NRHO), a member of the Earth-Moon halo orbit family, has been singularly demonstrated to meet multi-mission architectural constraints. In this paper, the challenges associated with operating human spacecraft in the NRHO are evaluated. Navigation accuracies and human vehicle process noise effects are applied to various station keeping strategies in order to obtain a reliable orbit maintenance algorithm. Additionally, the ability to absorb missed burns, construct phasing maneuvers to avoid eclipses and conduct rendezvous and proximity operations are examined.

  4. Applicability of meteor radiant determination methods depending on orbit type. I. High-eccentric orbits

    NASA Astrophysics Data System (ADS)

    Svoren, J.; Neslusan, L.; Porubcan, V.

    1993-07-01

    It is evident that there is no uniform method of calculating meteor radiants which would yield reliable results for all types of cometary orbits. In the present paper an analysis of this problem is presented, together with recommended methods for various types of orbits. Some additional methods resulting from mathematical modelling are presented and discussed together with Porter's, Steel-Baggaley's and Hasegawa's methods. In order to be able to compare how suitable the application of the individual radiant determination methods is, it is necessary to determine the accuracy with which they approximate real meteor orbits. To verify the accuracy with which the orbit of a meteoroid with at least one node at 1 AU fits the original orbit of the parent body, we applied the Southworth-Hawkins D-criterion (Southworth, R.B., Hawkins, G.S.: 1963, Smithson. Contr. Astrophys 7, 261). D<=0.1 indicates a very good fit of orbits, 0.1orbits, and D>0.2 the fit is rather poor and the change of orbit unrealistic. The optimal methods with the smallest values of D for given types of orbits are shown in two series of six plots. The new method of rotation around the line of apsides we propose is very appropriate in the region of small inclinations. There is no doubt that Hasegawa's omega-adjustment method (Hasegawa, I.: 1990, Publ. Astron. Soc. Japan 42, 175) has the widest application. A comparison of the theoretical radiants with the observed radiants of seven known meteor showers is also presented.

  5. Orbiter Crew Compartment Integration-Stowage

    NASA Technical Reports Server (NTRS)

    Morgan, L. Gary

    2007-01-01

    This viewgraph presentation describes the Orbiter Crew Compartment Integration (CCI) stowage. The evolution of orbiter crew compartment stowage volume is also described, along with photographs presented of the on-orbit volume stowage capacity.

  6. Orbit Determination Issues for Libration Point Orbits

    NASA Technical Reports Server (NTRS)

    Beckman, Mark; Bauer, Frank (Technical Monitor)

    2002-01-01

    Libration point mission designers require knowledge of orbital accuracy for a variety of analyses including station keeping control strategies, transfer trajectory design, and formation and constellation control. Past publications have detailed orbit determination (OD) results from individual libration point missions. This paper collects both published and unpublished results from four previous libration point missions (ISEE (International Sun-Earth Explorer) -3, SOHO (Solar and Heliospheric Observatory), ACE (Advanced Composition Explorer) and MAP (Microwave Anisotropy Probe)) supported by Goddard Space Flight Center's Guidance, Navigation & Control Center. The results of those missions are presented along with OD issues specific to each mission. All past missions have been limited to ground based tracking through NASA ground sites using standard range and Doppler measurement types. Advanced technology is enabling other OD options including onboard navigation using seaboard attitude sensors and the use of the Very Long Baseline Interferometry (VLBI) measurement Delta Differenced One-Way Range (DDOR). Both options potentially enable missions to reduce coherent dedicated tracking passes while maintaining orbital accuracy. With the increased projected loading of the DSN (Deep Space Network), missions must find alternatives to the standard OD scenario.

  7. Rates and characteristics of radiographically detected intracerebral cavernous malformations after cranial radiation therapy in pediatric cancer patients

    PubMed Central

    Hills, Nancy; Roddy, Erika; Randazzo, Dominica; Chettout, Nassim; Hess, Christopher; Cotter, Jennifer; Haas-Kogan, Daphne A.; Fullerton, Heather; Mueller, Sabine

    2014-01-01

    Rates and characteristics of intracerebral cavernous malformations (ICMs) after cranial radiation therapy (CRT) remain poorly understood. Herein we report on ICMs detected on follow+up imaging in pediatric cancer patients who received CRT at age ≤ 18 years from 1980 to 2009. Through chart reviews (n=362) and phone interviews (n=104) of a retrospective cohort we identified 10 patients with ICMs. The median latency time for detection of ICMs after CRT was 12 years (range 1+24 years) at a median age of 21.4 years (IQR 15+28). The cumulative incidence was 3% (95% CI 1+8%) at 10 years post CRT and 14% (95% CI 7+26%) at 15 years. Three patients underwent surgical resection. Two surgical specimens were pathologically similar to sporadically occurring ICMs; one was consistent with capillary telangiectasia. ICMs are common after CRT and can show a spectrum of histological features. PMID:25122111

  8. Update on Novel CCM Gene Mutations in Patients with Cerebral Cavernous Malformations.

    PubMed

    Scimone, Concetta; Bramanti, Placido; Alafaci, Concetta; Granata, Francesca; Piva, Francesco; Rinaldi, Carmela; Donato, Luigi; Greco, Federica; Sidoti, Antonina; D'Angelo, Rosalia

    2017-02-01

    Cerebral cavernous malformations (CCMs) are lesions affecting brain microvessels. The pathogenesis is not clearly understood. Conventional classification criterion is based on genetics, and thus, familial and sporadic forms can be distinguished; however, classification of sporadic cases with multiple lesions still remains uncertain. To date, three CCM causative genes have been identified: CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10. In our previous mutation screening, performed in a cohort of 95 Italian patients, with both sporadic and familial cases, we identified several mutations in CCM genes. This study represents further molecular screening in a cohort of 19 Italian patients enrolled by us in the few last years and classified into familial, sporadic and sporadic with multiple lesions cases. Direct sequencing and multiplex ligation-dependent probe amplification (MLPA) analysis were performed to detect point mutations and large genomic rearrangements, respectively. Effects of detected mutations and single-nucleotide polymorphisms (SNPs) were evaluated by an in silico approach and by western blot analysis. A novel nonsense mutation in CCM1 and a novel missense mutation in CCM2 were detected; moreover, several CCM2 gene polymorphisms in sporadic CCM patients were reported. We believe that these data enrich the mutation spectrum of CCM genes, which is useful for genetic counselling to identify both familial and sporadic CCM cases, as early as possible.

  9. Successful treatment of direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV without arterial puncture: the transvenous triple-overlay embolization (TAILOREd) technique.

    PubMed

    Huynh, Thien J; Morton, Ryan P; Levitt, Michael R; Ghodke, Basavaraj V; Wink, Onno; Hallam, Danial K

    2017-08-18

    We report successful transvenous treatment of direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV using a novel triple-overlay embolization (TAILOREd) technique without the need for arterial puncture, which is known to be highly risky in this patient group. The TAILOREd technique allowed for successful treatment using preoperative MR angiography as a three-dimensional overlay roadmap combined with cone beam CT and live fluoroscopy, precluding the need for an arterial puncture. 2017 BMJ Publishing Group Ltd.

  10. Polar orbits around binary stars

    NASA Astrophysics Data System (ADS)

    Egan, Greg

    2018-01-01

    Oks proposes the existence of a new class of stable planetary orbits around binary stars, in the shape of a helix on a conical surface whose axis of symmetry coincides with the interstellar axis, and rotates with the same orbital frequency as the binary pair. We show that this claim relies on the inappropriate use of an effective potential that is only applicable when the stars are held motionless. We also present numerical evidence that the only planetary orbits whose planes are initially orthogonal to the interstellar axis that remain stable on the time scale of the stellar orbit are ordinary polar orbits around one of the stars, and that the perturbations due to the binary companion do not rotate the plane of the orbit to maintain a fixed relationship with the axis.

  11. Recognition of microclimate zones through radon mapping, Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico

    USGS Publications Warehouse

    Cunningham, K.I.; LaRock, E.J.

    1991-01-01

    Radon concentrations range from <185 to 3,515 Bq m-3 throughout Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico. Concentrations in the entrance passages and areas immediately adjacent to these passages are controlled by outside air temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features.

  12. Sedna Orbit Animation

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This animation shows the location of the newly discovered planet-like object, dubbed 'Sedna,' in relation to the rest of the solar system. Starting at the inner solar system, which includes the orbits of Mercury, Venus, Earth, and Mars (all in yellow), the view pulls away through the asteroid belt and the orbits of the outer planets beyond (green). Pluto and the distant Kuiper Belt objects are seen next until finally Sedna comes into view. As the field widens the full orbit of Sedna can be seen along with its current location. Sedna is nearing its closest approach to the Sun; its 10,000 year orbit typically takes it to far greater distances. Moving past Sedna, what was previously thought to be the inner edge of the Oort cloud appears. The Oort cloud is a spherical distribution of cold, icy bodies lying at the limits of the Sun's gravitational pull. Sedna's presence suggests that this Oort cloud is much closer than scientists believed.

  13. Communications satellites in non-geostationary orbits

    NASA Technical Reports Server (NTRS)

    Price, Kent M.; Doong, Wen; Nguyen, Tuan Q.; Turner, Andrew E.; Weyandt, Charles

    1988-01-01

    The design of a satellite communications system in an orbit lower than GEO is described. Two sun-synchronous orbits which lie in the equatorial plane have been selected: (1) the apogee at constant time-of-day equatorial orbit, a highly eccentric orbit with five revolutions per day, which allows 77-135 percent more satellite mass to be placed in orbit than for GEO; and (2) the sun-synchronous 12-hour equatorial orbit, a circular orbit with two revolutions per day, which allows 23-29 percent more mass. The results of a life cycle economic analysis illustrate that nongeostationary satellite systems could be competitive with geostationary satellite systems.

  14. Gamma knife radiosurgery for symptomatic brainstem intra-axial cavernous malformations.

    PubMed

    Park, Seong-Hyun; Hwang, Sung-Kyoo

    2013-12-01

    The purpose of this study was to evaluate the efficacy and safety of gamma knife radiosurgery (GKRS) for the treatment of symptomatic brainstem intra-axial cavernous malformations (CMs) associated with high surgical morbidity. Twenty-one patients with symptomatic brainstem intra-axial CMs were treated by GKRS between 2005 and 2010. One patient was lost to follow-up. The median age of the patients was 39.5 years (range, 24-69 years). All patients had experienced 1 or more symptomatic hemorrhages before GKRS (range, 1-3). The median marginal radiation dose was 13 Gy, and the median volume of the malformation was 0.56 mL. The median follow-up period after radiosurgery was 32 months (range, 12-82 months; mean, 38.9 months). Before GKRS, 31 hemorrhages (1.55 per patient) were observed. The annual hemorrhage rate before GKRS was 39.5%, excluding the first hemorrhage. After GKRS, 1 hemorrhage (0.05 per patient) was identified. It occurred 6 months after radiosurgery. The patient showed complete recovery to a premorbid status with steroid medication. The annual hemorrhage rate after GKRS was 8.2% for the first 2 years. After the expected latency period, no hemorrhages were identified. One patient (5%) exhibited permanent paresthesia, which was a new neurologic symptom in absence of any hemorrhagic event, after the radiosurgery. GKRS seems to be relatively effective and safe for reducing the rebleeding rate of brainstem intra-axial CMs that have high surgical risk. Careful selection of a low marginal dose and an optimal radiosurgical technique are helpful to achieve good outcomes. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Outcome after surgical or conservative management of cerebral cavernous malformations.

    PubMed

    Moultrie, Fiona; Horne, Margaret A; Josephson, Colin B; Hall, Julie M; Counsell, Carl E; Bhattacharya, Jo J; Papanastassiou, Vakis; Sellar, Robin J; Warlow, Charles P; Murray, Gordon D; Al-Shahi Salman, Rustam

    2014-08-12

    There have been few comparative studies of microsurgical excision vs conservative management of cerebral cavernous malformations (CCM) and none of them has reliably demonstrated a statistically and clinically significant difference. We conducted a prospective, population-based study to identify and independently validate definite CCM diagnoses first made in 1999-2003 in Scottish adult residents. We used multiple sources of prospective follow-up to assess adults' dependence and to identify and independently validate outcome events. We used univariate and multivariable survival analyses to test the influence of CCM excision on outcome, adjusted for prognostic factors and baseline imbalances. Of 134 adults, 25 underwent CCM excision; these adults were younger (34 vs 43 years at diagnosis, p = 0.004) and more likely to present with symptomatic intracranial hemorrhage or focal neurologic deficit than adults managed conservatively (48% vs 26%; odds ratio 2.7, 95% confidence interval [CI] 1.1-6.5). During 5 years of follow-up, CCM excision was associated with a deterioration to an Oxford Handicap Scale score 2-6 sustained over at least 2 successive years (adjusted hazard ratio [HR] 2.2, 95% CI 1.1-4.3) and the occurrence of symptomatic intracranial hemorrhage or new focal neurologic deficit (adjusted HR 3.6, 95% CI 1.3-10.0). CCM excision was associated with worse outcomes over 5 years compared to conservative management. Long-term follow-up will determine whether this difference is sustained over patients' lifetimes. Meanwhile, a randomized controlled trial appears justified. This study provides Class III evidence that CCM excision worsens short-term disability scores and increases the risk of symptomatic intracranial hemorrhage and new focal neurologic deficits. © 2014 American Academy of Neurology.

  16. A Survey Of Earth-Moon Libration Orbits: Stationkeeping Strategies And Intra-Orbit Transfers

    NASA Technical Reports Server (NTRS)

    Folta, David; Vaughn, Frank

    2004-01-01

    Cislunar space is a readily accessible region that may well develop into a prime staging area in the effort to colonize space near Earth or to colonize the Moon. While there have been statements made by various NASA programs regarding placement of resources in orbit about the Earth-Moon Lagrangian locations, there is no survey of the total cost associated with attaining and maintaining these unique orbits in an operational fashion. Transfer trajectories between these orbits required for assembly, servicing, and positioning of these resources have not been extensively investigated. These orbits are dynamically similar to those used for the Sun-Earth missions, but differences in governing gravitational ratios and perturbation sources result in unique characteristics. We implement numerical computations using high fidelity models and linear and nonlinear targeting techniques to compute the various maneuver (Delta)V and temporal costs associated with orbits about each of the Earth-Moon Lagrangian locations (L1, L2, L3, L4, and L5). From a dynamical system standpoint, we speak to the nature of these orbits and their stability. We address the cost of transfers between each pair of Lagrangian locations.

  17. Crystal Structure of CCM3, a Cerebral Cavernous Malformation Protein Critical for Vascular Integrity

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

    Li, X.; Zhang, R; Zhang, H

    CCM3 mutations are associated with cerebral cavernous malformation (CCM), a disease affecting 0.1-0.5% of the human population. CCM3 (PDCD10, TFAR15) is thought to form a CCM complex with CCM1 and CCM2; however, the molecular basis for these interactions is not known. We have determined the 2.5 {angstrom} crystal structure of CCM3. This structure shows an all {alpha}-helical protein containing two domains, an N-terminal dimerization domain with a fold not previously observed, and a C-terminal focal adhesion targeting (FAT)-homology domain. We show that CCM3 binds CCM2 via this FAT-homology domain and that mutation of a highly conserved FAK-like hydrophobic pocket (HP1)more » abrogates CCM3-CCM2 interaction. This CCM3 FAT-homology domain also interacts with paxillin LD motifs using the same surface, and partial CCM3 co-localization with paxillin in cells is lost on HP1 mutation. Disease-related CCM3 truncations affect the FAT-homology domain suggesting a role for the FAT-homology domain in the etiology of CCM.« less

  18. Spiral Orbit Tribometer

    NASA Technical Reports Server (NTRS)

    Pepper, Stephen V.; Jones, William R., Jr.; Kingsbury, Edward; Jansen, Mark J.

    2007-01-01

    The spiral orbit tribometer (SOT) bridges the gap between full-scale life testing and typically unrealistic accelerated life testing of ball-bearing lubricants in conjunction with bearing ball and race materials. The SOT operates under realistic conditions and quickly produces results, thereby providing information that can guide the selection of lubricant, ball, and race materials early in a design process. The SOT is based upon a simplified, retainerless thrust bearing comprising one ball between flat races (see figure). The SOT measures lubricant consumption and degradation rates and friction coefficients in boundary lubricated rolling and pivoting contacts. The ball is pressed between the lower and upper races with a controlled force and the lower plate is rotated. The combination of load and rotation causes the ball to move in a nearly circular orbit that is, more precisely, an opening spiral. The spiral s pitch is directly related to the friction coefficient. At the end of the orbit, the ball contacts the guide plate, restoring the orbit to its original radius. The orbit is repeatable throughout the entire test. A force transducer, mounted in-line with the guide plate, measures the force between the ball and the guide plate, which directly relates to the friction coefficient. The SOT, shown in the figure, can operate in under ultra-high vacuum (10(exp -9) Torr) or in a variety of gases at atmospheric pressure. The load force can be adjusted between 45 and 450 N. By varying the load force and ball diameter, mean Hertzian stresses between 0.5 and 5.0 GPa can be obtained. The ball s orbital speed range is between 1 and 100 rpm.

  19. Pictorial essay: Orbital tuberculosis

    PubMed Central

    Narula, Mahender K; Chaudhary, Vikas; Baruah, Dhiraj; Kathuria, Manoj; Anand, Rama

    2010-01-01

    Tuberculosis of the orbit is rare, even in places where tuberculosis is endemic. The disease may involve soft tissue, the lacrimal gland, or the periosteum or bones of the orbital wall. Intracranial extension, in the form of extradural abscess, and infratemporal fossa extension has been described. This pictorial essay illustrates the imaging findings of nine histopathologically confirmed cases of orbital tuberculosis. All these patients responded to antituberculous treatment. PMID:20351984

  20. Precise Orbit Determination for ALOS

    NASA Technical Reports Server (NTRS)

    Nakamura, Ryo; Nakamura, Shinichi; Kudo, Nobuo; Katagiri, Seiji

    2007-01-01

    The Advanced Land Observing Satellite (ALOS) has been developed to contribute to the fields of mapping, precise regional land coverage observation, disaster monitoring, and resource surveying. Because the mounted sensors need high geometrical accuracy, precise orbit determination for ALOS is essential for satisfying the mission objectives. So ALOS mounts a GPS receiver and a Laser Reflector (LR) for Satellite Laser Ranging (SLR). This paper deals with the precise orbit determination experiments for ALOS using Global and High Accuracy Trajectory determination System (GUTS) and the evaluation of the orbit determination accuracy by SLR data. The results show that, even though the GPS receiver loses lock of GPS signals more frequently than expected, GPS-based orbit is consistent with SLR-based orbit. And considering the 1 sigma error, orbit determination accuracy of a few decimeters (peak-to-peak) was achieved.

  1. Spacecraft Orbit Anomaly Representation Using Thrust-Fourier-Coefficients with Orbit Determination Toolbox

    NASA Astrophysics Data System (ADS)

    Ko, H.; Scheeres, D.

    2014-09-01

    Representing spacecraft orbit anomalies between two separate states is a challenging but an important problem in achieving space situational awareness for an active spacecraft. Incorporation of such a capability could play an essential role in analyzing satellite behaviors as well as trajectory estimation of the space object. A general way to deal with the anomaly problem is to add an estimated perturbing acceleration such as dynamic model compensation (DMC) into an orbit determination process based on pre- and post-anomaly tracking data. It is a time-consuming numerical process to find valid coefficients to compensate for unknown dynamics for the anomaly. Even if the orbit determination filter with DMC can crudely estimate an unknown acceleration, this approach does not consider any fundamental element of the unknown dynamics for a given anomaly. In this paper, a new way of representing a spacecraft anomaly using an interpolation technique with the Thrust-Fourier-Coefficients (TFCs) is introduced and several anomaly cases are studied using this interpolation method. It provides a very efficient way of reconstructing the fundamental elements of the dynamics for a given spacecraft anomaly. Any maneuver performed by a satellite transitioning between two arbitrary orbital states can be represented as an equivalent maneuver using an interpolation technique with the TFCs. Given unconnected orbit states between two epochs due to a spacecraft anomaly, it is possible to obtain a unique control law using the TFCs that is able to generate the desired secular behavior for the given orbital changes. This interpolation technique can capture the fundamental elements of combined unmodeled anomaly events. The interpolated orbit trajectory, using the TFCs compensating for a given anomaly, can be used to improve the quality of orbit fits through the anomaly period and therefore help to obtain a good orbit determination solution after the anomaly. Orbit Determination Toolbox (ODTBX

  2. Analysis of unstable periodic orbits and chaotic orbits in the one-dimensional linear piecewise-smooth discontinuous map

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

    Rajpathak, Bhooshan, E-mail: bhooshan@ee.iitb.ac.in; Pillai, Harish K., E-mail: hp@ee.iitb.ac.in; Bandyopadhyay, Santanu, E-mail: santanu@me.iitb.ac.in

    2015-10-15

    In this paper, we analytically examine the unstable periodic orbits and chaotic orbits of the 1-D linear piecewise-smooth discontinuous map. We explore the existence of unstable orbits and the effect of variation in parameters on the coexistence of unstable orbits. Further, we show that this structuring is different from the well known period adding cascade structure associated with the stable periodic orbits of the same map. Further, we analytically prove the existence of chaotic orbit for this map.

  3. Orbit Determination and Navigation Software Testing for the Mars Reconnaissance Orbiter

    NASA Technical Reports Server (NTRS)

    Pini, Alex

    2011-01-01

    During the extended science phase of the Mars Reconnaissance Orbiter's lifecycle, the operational duties pertaining to navigation primarily involve orbit determination. The orbit determination process utilizes radiometric tracking data and is used for the prediction and reconstruction of MRO's trajectories. Predictions are done twice per week for ephemeris updates on-board the spacecraft and for planning purposes. Orbit Trim Maneuvers (OTM-s) are also designed using the predicted trajectory. Reconstructions, which incorporate a batch estimator, provide precise information about the spacecraft state to be synchronized with scientific measurements. These tasks were conducted regularly to validate the results obtained by the MRO Navigation Team. Additionally, the team is in the process of converting to newer versions of the navigation software and operating system. The capability to model multiple densities in the Martian atmosphere is also being implemented. However, testing outputs among these different configurations was necessary to ensure compliance to a satisfactory degree.

  4. Classification of Stellar Orbits Near Corotation

    NASA Astrophysics Data System (ADS)

    Breet, Jessica; Daniel, Kathryne J.; Bryn Mawr College Galaxy Lab

    2018-01-01

    The process of radial migration is frequently invoked as an important process to spiral galaxy evolution, but the physical properties that determine the efficiency of radial migration are poorly defined. In order for a star to migrate radially it must first be trapped in a resonant orbit at the corotation radius of a spiral pattern. Stars in such trapped orbits have changing average orbital radii — and thus orbital angular momenta — without any change in orbital eccentricity. It follows that transient spiral patterns can permanently rearrange the distribution of orbital angular momentum in the disk without kinematically heating it. It is also known that orbits can also have a significant dynamical response at Lindblad Resonances (LRs), where the Ultraharmonic Lindblad Resonances (ULRs) have a lesser impact on the disk. The goal of our project is to examine and constrain the efficiency of radial migration via an investigation into whether or not stars in trapped orbits have a dynamical response at the ULRs. We produced a dataset of nearly 105 orbits with initial conditions across a range of radii and 2-D velocities. We then classified these orbits into four categories based on analytic criteria for whether or not they are in trapped orbits and/or cross the ULR over 1 gigayear. Preliminary investigations show that trapped orbits that also meet the ULR have a chaotic response, putting a potential limit on the efficiency of radial migration.

  5. Intial orbit determination results for Jason-1: towards a 1-cm orbit

    NASA Technical Reports Server (NTRS)

    Haines, B. J.; Haines, B.; Bertiger, W.; Desai, S.; Kuang, D.; Munson, T.; Reichert, A.; Young, L.; Willis, P.

    2002-01-01

    The U.S/France Jason-1 oceanographic mission is carrying state-of-the-art radiometric tracking systems (GPS and Doris) to support precise orbit determination (POD) requirements. The performance of the systems is strongly reflected in the early POD results. Results of both internal and external (e.g., satellite laser ranging) comparisons support that the 2.5 cm radial Rh4S requirement is being readily met, and provide reasons for optimism that 1 cm can be achieved. We discuss the POD strategy underlying these orbits, as well as the challenging issues that bear on the understanding and characterization of an orbit solution at the l-cm level. We also describe a system for producing science quality orbits in near real time in order to support emerging applications in operational oceanography.

  6. Orbiter thermal protection system

    NASA Technical Reports Server (NTRS)

    Dotts, R. L.; Curry, D. M.; Tillian, D. J.

    1985-01-01

    The major material and design challenges associated with the orbiter thermal protection system (TPS), the various TPS materials that are used, the different design approaches associated with each of the materials, and the performance during the flight test program are described. The first five flights of the Orbiter Columbia and the initial flight of the Orbiter Challenger provided the data necessary to verify the TPS thermal performance, structural integrity, and reusability. The flight performance characteristics of each TPS material are discussed, based on postflight inspections and postflight interpretation of the flight instrumentation data. Flights to date indicate that the thermal and structural design requirements for the orbiter TPS are met and that the overall performance is outstanding.

  7. Aerobraking orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Scott, Carl D. (Inventor); Nagy, Kornel (Inventor); Roberts, Barney B. (Inventor); Ried, Robert C. (Inventor); Kroll, Kenneth R. (Inventor); Gamble, Joe (Inventor)

    1989-01-01

    An aerobraking orbital transfer vehicle which includes an aerobraking device which also serves as a heat shield in the shape of a raked-off elliptic or circular cone with a circular or elliptical base, and with an ellipsoid or other blunt shape nose. The aerobraking device is fitted with a toroid-like skirt and is integral with the support structure of the propulsion system and other systems of the space vehicle. The vehicle is intended to be transported in components to a space station in lower earth orbit where it is assembled for use as a transportation system from low earth orbit to geosynchronous earth orbit and return. Conventional guidance means are included for autonomous flight.

  8. MOOSE: Manned On-Orbit Servicing Equipment

    NASA Technical Reports Server (NTRS)

    Budinoff, J. (Editor); Leontsinis, N. (Editor); Lane, J. (Editor); Singh, R. (Editor); Angelone, K.; Boswell, C.; Chamberlain, I.; Concha, M.; Corrodo, M.; Custodio, O.

    1993-01-01

    The ability to service satellites has thus far been limited to low earth orbit platforms within reach of the Space Shuttle. Other orbits, such as geosynchronous orbits containing high-value spacecraft have not been attainable by a servicing vehicle. The useful life of a satellite can be extended by replacing spent propellant and damaged orbital replacement units, forestalling the need for eventual replacement. This growing need for satellite on-orbits servicing can be met by the Manned On-Orbit Servicing Equipment (MOOSE). Missions requiring orbit transfer capability, precision manipulation and maneuvering, and man-in-the-loop control can be accomplished using MOOSE. MOOSE is a flexible, reusable, single operator, aerobraking spacecraft designed to refuel, repair, and service orbiting spacecraft. MOOSE will be deployed from Space Station Freedom, (SSF), where it will be stored, resupplied, and refurbished.

  9. Rational orbits around charged black holes

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

    Misra, Vedant; Levin, Janna; Institute for Strings, Cosmology and Astroparticle Physics, Columbia University, New York, New York 10027

    2010-10-15

    We show that all eccentric timelike orbits in Reissner-Nordstroem spacetime can be classified using a taxonomy that draws upon an isomorphism between periodic orbits and the set of rational numbers. By virtue of the fact that the rationals are dense, the taxonomy can be used to approximate aperiodic orbits with periodic orbits. This may help reduce computational overhead for calculations in gravitational wave astronomy. Our dynamical systems approach enables us to study orbits for both charged and uncharged particles in spite of the fact that charged particle orbits around a charged black hole do not admit a simple one-dimensional effectivemore » potential description. Finally, we show that comparing periodic orbits in the Reissner-Nordstroem and Schwarzschild geometries enables us to distinguish charged and uncharged spacetimes by looking only at the orbital dynamics.« less

  10. Wobbly Planet Orbital Schematic Illustration

    NASA Image and Video Library

    2014-02-04

    This illustration shows the unusual orbit of planet Kepler-413b around a close pair of orange and red dwarf stars. The planet 66-day orbit is tilted 2.5 degrees with respect to the plane of the binary stars orbit.

  11. The Lunar Orbital Prospector

    NASA Technical Reports Server (NTRS)

    Redd, Frank J.; Cantrell, James N.; Mccurdy, Greg

    1992-01-01

    The establishment of lunar bases will not end the need for remote sensing of the lunar surface by orbiting platforms. Human and robotic surface exploration will necessarily be limited to some proximate distance from the support base. Near real-time, high-resolution, global characterization of the lunar surface by orbiting sensing systems will continue to be essential to the understanding of the Moon's geophysical structure and the location of exploitable minerals and deposits of raw materials. The Lunar Orbital Prospector (LOP) is an orbiting sensing platform capable of supporting a variety of modular sensing packages. Serviced by a lunar-based shuttle, the LOP will permit the exchange of instrument packages to meet evolving mission needs. The ability to recover, modify, and rotate sensing packages allows their reuse in varying combinations. Combining this flexibility with robust orbit modification capabilities and near real-time telemetry links provides considerable system responsiveness. Maintenance and modification of the LOP orbit are accomplished through use of an onboard propulsion system that burns lunar-supplied oxygen and aluminum. The relatively low performance of such a system is more than compensated for by the elimination of the need for Earth-supplied propellants. The LOP concept envisions a continuous expansion of capability through the incorporation of new instrument technologies and the addition of platforms.

  12. Orbit determination of the Next-Generation Beidou satellites with Intersatellite link measurements and a priori orbit constraints

    NASA Astrophysics Data System (ADS)

    Ren, Xia; Yang, Yuanxi; Zhu, Jun; Xu, Tianhe

    2017-11-01

    Intersatellite Link (ISL) technology helps to realize the auto update of broadcast ephemeris and clock error parameters for Global Navigation Satellite System (GNSS). ISL constitutes an important approach with which to both improve the observation geometry and extend the tracking coverage of China's Beidou Navigation Satellite System (BDS). However, ISL-only orbit determination might lead to the constellation drift, rotation, and even lead to the divergence in orbit determination. Fortunately, predicted orbits with good precision can be used as a priori information with which to constrain the estimated satellite orbit parameters. Therefore, the precision of satellite autonomous orbit determination can be improved by consideration of a priori orbit information, and vice versa. However, the errors of rotation and translation in a priori orbit will remain in the ultimate result. This paper proposes a constrained precise orbit determination (POD) method for a sub-constellation of the new Beidou satellite constellation with only a few ISLs. The observation model of dual one-way measurements eliminating satellite clock errors is presented, and the orbit determination precision is analyzed with different data processing backgrounds. The conclusions are as follows. (1) With ISLs, the estimated parameters are strongly correlated, especially the positions and velocities of satellites. (2) The performance of determined BDS orbits will be improved by the constraints with more precise priori orbits. The POD precision is better than 45 m with a priori orbit constrain of 100 m precision (e.g., predicted orbits by telemetry tracking and control system), and is better than 6 m with precise priori orbit constraints of 10 m precision (e.g., predicted orbits by international GNSS monitoring & Assessment System (iGMAS)). (3) The POD precision is improved by additional ISLs. Constrained by a priori iGMAS orbits, the POD precision with two, three, and four ISLs is better than 6, 3, and 2

  13. Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels

    NASA Astrophysics Data System (ADS)

    Fabbris, G.; Meyers, D.; Okamoto, J.; Pelliciari, J.; Disa, A. S.; Huang, Y.; Chen, Z.-Y.; Wu, W. B.; Chen, C. T.; Ismail-Beigi, S.; Ahn, C. H.; Walker, F. J.; Huang, D. J.; Schmitt, T.; Dean, M. P. M.

    2016-09-01

    Resonant inelastic x-ray scattering is used to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO3-LaNiO3-3 ×(LaA l O3) , a system with exceptionally large polarization, as a model system. We find that heterostructuring generates only minor changes in the Ni 3 d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K -edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This provides an explanation for the limited success of theoretical predictions based on tuning orbital energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.

  14. Use of Orbital Conformer to Improve Speech in Patients with Confluent Maxillectomy and Orbital Defects

    PubMed Central

    Colebeck, Amanda C.; Kase, Michael T.; Nichols, Cindy B.; Golden, Marjorie; Huryn, Joseph M.

    2016-01-01

    The basic objective in prosthetic restoration of confluent maxillary and orbital defects is to achieve a comfortable, cosmetically acceptable prosthesis that restores speech, deglutition, and mastication. It is a challenging task complicated by the size and shape of the defects. The maxillary obturator prosthesis often satisfies the objective of adequate deglutition; however, orbital defects that are not obturated in the medial septal or posterior walls allow air to escape, negatively impacting phonation. This article describes a technique to achieve favorable prosthetic rehabilitation in a patient with a maxillectomy and ipsilateral orbital exenteration. The prosthetic components include maxillary obturator, orbital conformer, and orbital prosthesis connected using rigid magnetic attachments. PMID:25953143

  15. Orbiter windward surface entry Heating: Post-orbital flight test program update

    NASA Technical Reports Server (NTRS)

    Harthun, M. H.; Blumer, C. B.; Miller, B. A.

    1983-01-01

    Correlations of orbiter windward surface entry heating data from the first five flights are presented with emphasis on boundary layer transition and the effects of catalytic recombination. Results show that a single roughness boundary layer transition correlation developed for spherical element trips works well for the orbiter tile system. Also, an engineering approach for predicting heating in nonequilibrium flow conditions shows good agreement with the flight test data in the time period of significant heating. The results of these correlations, when used to predict orbiter heating for a high cross mission, indicate that the thermal protection system on the windward surface will perform successfully in such a mission.

  16. Backgrounds, radiation damage, and spacecraft orbits

    NASA Astrophysics Data System (ADS)

    Grant, Catherine E.; Miller, Eric D.; Bautz, Mark W.

    2017-08-01

    The scientific utility of any space-based observatory can be limited by the on-orbit charged particle background and the radiation-induced damage. All existing and proposed missions have had to make choices about orbit selection, trading off the radiation environment against other factors. We present simulations from ESA’s SPace ENVironment Information System (SPENVIS) of the radiation environment for spacecraft in a variety of orbits, from Low Earth Orbit (LEO) at multiple inclinations to High Earth Orbit (HEO) to Earth-Sun L2 orbit. We summarize how different orbits change the charged particle background and the radiation damage to the instrument. We also discuss the limitations of SPENVIS simulations, particularly outside the Earth’s trapped radiation and point to new resources attempting to address those limitations.

  17. Orbital ordering in FeV2O4: Spinel with two orbitally active sites

    NASA Astrophysics Data System (ADS)

    Sarkar, Soumyajit; Saha-Dasgupta, T.

    2011-12-01

    By employing first-principles electronic structure calculations, we investigate orbital ordering in FeV2O4, a spinel with orbital degrees of freedom both at Fe and V sites that exhibits two tetragonal phases, one compressed at high temperature and another elongated at low temperature. Our first-principles study shows the ferro-orbital ordering of dx2-y2 and d3z2-r2 types at Fe sites at the high- and low-temperature phases, respectively. The orbital ordering at V sites is found to consist of orbital chains running along different directions with orbitals rotated alternatively within each chain, similar to that found for MnV2O4 [S. Sarkar , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.102.216405 102, 216405 (2009)]. Further, we find that the single-ion anisotropy effect with hard and easy c axis favors the compressed and elongated tetrahedral shapes. This gives rise to magnetocrystalline anisotropy-dependent shapes, similar to that reported in the context of rare-earth-based magnetic shape memory alloys.

  18. The Solar Orbiter Heliospheric Imager (SoloHI) for the Solar Orbiter Mission

    NASA Astrophysics Data System (ADS)

    Howard, R.; Colaninno, R. C.; Plunkett, S. P.; Thernisien, A. F.; Wang, D.; Rich, N.; Korendyke, C.; Socker, D. G.; Linton, M.; McMullin, D. R.; Vourlidas, A.; Liewer, P. C.; De Jong, E.; Velli, M.; Mikic, Z.; Bothmer, V.; Philippe, L.; Carter, M. T.

    2017-12-01

    The SoloHI instrument has completed its development effort and has been integrated onto the Solar Orbiter (SolO) spacecraft. The SolO mission, scheduled for launch in February 2019, will undergo gravity assist maneuvers around Venus to change both the perihelion distance as well as the plane of the orbit to ultimately achieve a minimum perihelion of 0.28 AU and an orbital inclination of about 35° relative to the ecliptic plane. The remote sensing instruments will operate for three 10-day periods out of the nominal 6-month orbit. SoloHI will observe sunlight scattered by free electrons in the corona/solar wind from 5° to 45° elongation in visible wavelengths and will provide a coupling between remote sensing and in situ observations. It is very similar to the HI-1 instrument on STEREO/SECCHI except that the FOV is twice the size at 40o. We present our efforts to prepare for the mission including our observing plans, quick-look plans and some results of the calibration activities. We gratefully acknowledge the support of the NASA Solar Orbiter Collaboration project.

  19. Involvement of Methicillin-Susceptible Staphylococcus aureus Related to Sequence Type 25 and Harboring pvl Genes in a Case of Carotid Cavernous Fistula after Community-Associated Sepsis

    PubMed Central

    Damasco, Paulo V.; Chamon, Raiane C.; Barbosa, Angélica T. L.; da Cunha, Sérgio; Aquino, José H. W.; Cavalcante, Fernanda S.

    2012-01-01

    Staphylococcus aureus encoding Panton-Valentine leukocidin (PVL) genes has become the cause of life-threatening infections. We describe a case of carotid cavernous fistula after bacteremia in a 12-year-old male, caused by a methicillin-susceptible S. aureus isolate carrying the pvl, fnbA, and ebpS genes and related to sequence type 25 (ST25). The patient's condition was complicated by pleural empyema and osteomyelitis in the right femur. The patient was discharged in good clinical condition after 160 days of hospitalization. PMID:22090398

  20. Involvement of methicillin-susceptible Staphylococcus aureus related to sequence type 25 and harboring pvl genes in a case of carotid cavernous fistula after community-associated sepsis.

    PubMed

    Damasco, Paulo V; Chamon, Raiane C; Barbosa, Angélica T L; da Cunha, Sérgio; Aquino, José H W; Cavalcante, Fernanda S; Dos Santos, Kátia R N

    2012-01-01

    Staphylococcus aureus encoding Panton-Valentine leukocidin (PVL) genes has become the cause of life-threatening infections. We describe a case of carotid cavernous fistula after bacteremia in a 12-year-old male, caused by a methicillin-susceptible S. aureus isolate carrying the pvl, fnbA, and ebpS genes and related to sequence type 25 (ST25). The patient's condition was complicated by pleural empyema and osteomyelitis in the right femur. The patient was discharged in good clinical condition after 160 days of hospitalization.

  1. Orbiter CIU/IUS communications hardware evaluation

    NASA Technical Reports Server (NTRS)

    Huth, G. K.

    1979-01-01

    The DOD and NASA inertial upper stage communication system design, hardware specifications and interfaces were analyzed to determine their compatibility with the Orbiter payload communications equipment (Payload Interrogator, Payload Signal Processors, Communications Interface Unit, and the Orbiter operational communications equipment (the S-Band and Ku-band systems). Topics covered include (1) IUS/shuttle Orbiter communications interface definition; (2) Orbiter avionics equipment serving the IUS; (3) IUS communication equipment; (4) IUS/shuttle Orbiter RF links; (5) STDN/TDRS S-band related activities; and (6) communication interface unit/Orbiter interface issues. A test requirement plan overview is included.

  2. Precise Tracking of the Magellan and Pioneer Venus Orbiters by Same-Beam Interferometry. Part 2: Orbit Determination Analysis

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Border, J. S.; Nandi, S.; Zukor, K. S.

    1993-01-01

    A new radio metric positioning technique has demonstrated improved orbit determination accuracy for the Magellan and Pioneer Venus Orbiter orbiters. The new technique, known as Same-Beam Interferometry (SBI), is applicable to the positioning of multiple planetary rovers, landers, and orbiters which may simultaneously be observed in the same beamwidth of Earth-based radio antennas. Measurements of carrier phase are differenced between spacecraft and between receiving stations to determine the plane-of-sky components of the separation vector(s) between the spacecraft. The SBI measurements complement the information contained in line-of-sight Doppler measurements, leading to improved orbit determination accuracy. Orbit determination solutions have been obtained for a number of 48-hour data arcs using combinations of Doppler, differenced-Doppler, and SBI data acquired in the spring of 1991. Orbit determination accuracy is assessed by comparing orbit solutions from adjacent data arcs. The orbit solution differences are shown to agree with expected orbit determination uncertainties. The results from this demonstration show that the orbit determination accuracy for Magellan obtained by using Doppler plus SBI data is better than the accuracy achieved using Doppler plus differenced-Doppler by a factor of four and better than the accuracy achieved using only Doppler by a factor of eighteen. The orbit determination accuracy for Pioneer Venus Orbiter using Doppler plus SBI data is better than the accuracy using only Doppler data by 30 percent.

  3. Report on orbital debris

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The success of space endeavors depends upon a space environment sufficiently free of debris to enable the safe and dependable operation of spacecraft. An environment overly cluttered with debris would threaten the ability to utilize space for a wide variety of scientific, technological, military, and commercial purposes. Man made space debris (orbital debris) differs from natural meteoroids because it remains in earth orbit during its lifetime and is not transient through the space around the Earth. The orbital debris environment is considered. The space environment is described along with sources of orbital debris. The current national space policy is examined, along with ways to minimize debris generation and ways to survive the debris environment. International efforts, legal issues and commercial regulations are also examined.

  4. Planning Orbiter Flights

    NASA Technical Reports Server (NTRS)

    Harris, H. M.; Bergam, M. J.; Kim, S. L.; Smith, E. A.

    1987-01-01

    Shuttle Mission Design and Operations Software (SMDOS) assists in design and operation of missions involving spacecraft in low orbits around Earth by providing orbital and graphics information. SMDOS performs following five functions: display two world and two polar maps or any user-defined window 5 degrees high in latitude by 5 degrees wide in longitude in one of eight standard projections; designate Earth sites by points or polygon shapes; plot spacecraft ground track with 1-min demarcation lines; display, by means of different colors, availability of Tracking and Data Relay Satellite to Shuttle; and calculate available times and orbits to view particular site, and corresponding look angles. SMDOS written in Laboratory Micro-systems FORTH (1979 standard)

  5. JSC Orbital Debris Website Description

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.

    2006-01-01

    Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as

  6. The effect of cavernous nerve traction on erectile function in rats

    PubMed Central

    Chen, Liping; Wang, Tao; Wang, Shaogang; Liu, Jihong

    2017-01-01

    We performed this study to evaluate the effect of cavernous nerve (CN) traction on erectile function in rats. Thirty-two 8- week-old Sprague–Dawley rats were divided into four groups: control, 1-minute CN traction, 2-minute CN traction, and 2-minute CN crush. CN traction was performed using a glass hook with a tensile force of 0.2 Newton. One month later, the mean arterial pressure (MAP) and intracavernosal pressure (ICP) in response to CN stimulation were measured to assess erectile function. The penis and major pelvic ganglion (MPG) were harvested to explore the expression of neuronal nitric oxide synthase (nNOS) and neurofilament, fibrosis and apoptosis. The ICP/MAP ratio was reduced in the 2-minute CN traction group compared with the control group (P < 0.05). The ICP/MAP ratio in the CN crush group was lower than in the other three groups (P < 0.05, for each). Expression of nNOS in both MPG and dorsal penile nerve was lower in the CN traction group than in the control group, but was higher than in the CN crush group (P < 0.05). Nerve fiber number in the dorsal penile nerve was reduced by 2-minute CN traction (P < 0.05). The ratios of collagen to smooth muscle content and the apoptosis were both increased the in 2-minute CN traction group compared with the control group (P < 0.05). The findings indicate that CN traction is an effective CN injury model and the injury it caused is relatively mild compared with the CN crush model. PMID:28982169

  7. Transarterial treatment of direct carotico-cavernous fistulas with coils and Onyx.

    PubMed

    Ramalingaiah, Arvinda Hanumanthapura; Prasad, Chandrajit; Sabharwal, Paramveer Singh; Saini, Jitender; Pandey, Paritosh

    2013-10-01

    The purpose of this study was to evaluate the role of combination of liquid embolic agent ethylene vinyl alcohol copolymer (Onyx) and detachable coils in the treatment of direct carotico-cavernous fistulas (CCFs). We prospectively collected clinical and radiological data of all patients who underwent embolization of direct CCFs at our institution over a period of 21 months. The clinical parameters, angioarchitecture, presence of cortical venous reflux, volume of Onyx used, number of coils used, extent of embolization and complications were recorded. A total of 21 consecutive patients (18 men and 3 women, 14 to 48 years) with direct CCF underwent embolization with a combination of coils and Onyx. Embolization was done through the arterial route in all cases. Complete obliteration of the fistula was achieved in 19 of 21 cases. Cast embolization in middle cerebral artery occurred in one patient; however, the cast was completely retrieved with Solitaire device, and the patient did not have any neurological deficit. All completely treated patients reported relief of symptoms at varying intervals. At 6-month follow-up, none of the patients with complete occlusion of the fistula showed any recurrence. The adjuvant use of Onyx with detachable coils in direct CCF through the arterial route is a safe and effective method for embolization with immediate and complete occlusion of the fistula. To the best of our knowledge, this is the first case series of demonstration of arterial use of Onyx with coils in the treatment of direct CCFs.

  8. Pioneer probe mission with orbiter option

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A spacecraft is described which is based on Pioneer 10 and 11, and existing propulsion technology; it can transport and release a probe for entry into Jupiter's atmosphere, and subsequently maneuver to place the spacecraft in orbit about Jupiter. Orbital operations last 3 years and include maneuvers to provide multiple close satellite encounters which allow the orbit to be significantly changed to explore different parts of the magnetosphere. A mission summary, a guide to related documents, and background information about Jupiter are presented along with mission analysis over the complete mission profile. Other topics discussed include the launch, interplanetary flight, probe release and orbit deflection, probe entry, orbit selection, orbit insertion, periapsis raising, spacecraft description, and the effects of Jupiter's radiation belt on both orbiter and the probe.

  9. Development of syndrome of inappropriate antidiuretic hormone secretion (SIADH) after Onyx embolisation of a cavernous carotid fistula

    PubMed Central

    Chen, Tsinsue; Kalani, M Yashar S; Ducruet, Andrew F; Albuquerque, Felipe C; McDougall, Cameron G

    2016-01-01

    Patients with cavernous carotid fistulas (CCFs) can present with pituitary hypoperfusion and hypopituitarism; however, there are no previous reports of pituitary or hormonal abnormalities developing after CCF embolisation in an asymptomatic patient. We describe a patient with no hormonal abnormalities who developed syndrome of inappropriate antidiuretic hormone (SIADH) secretion after CCF embolisation. The patient had bilateral indirect CCFs, which were completely embolised via a transvenous approach, and was neurologically stable postoperatively and discharged. In the subsequent 2 weeks the patient was readmitted twice for acute hyponatraemia and a tonic-clonic seizure. Laboratory studies revealed severe SIADH. Clinical status and sodium levels improved after treatment. One year later the patient was weaned off all medications and remained neurologically stable. SIADH may be a delayed phenomenon after CCF embolisation. Given the proximity of embolised vessels to the pituitary's vascular supply, CCF treatment may result in flow disturbance, ischaemia and hormonal abnormalities. PMID:27001597

  10. Orbit determination and gravity field recovery from Doppler tracking data to the Lunar Reconnaissance Orbiter

    NASA Astrophysics Data System (ADS)

    Maier, Andrea; Baur, Oliver

    2016-03-01

    We present results for Precise Orbit Determination (POD) of the Lunar Reconnaissance Orbiter (LRO) based on two-way Doppler range-rates over a time span of ~13 months (January 3, 2011 to February 9, 2012). Different orbital arc lengths and various sets of empirical parameters were tested to seek optimal parametrization. An overlap analysis covering three months of Doppler data shows that the most precise orbits are obtained using an arc length of 2.5 days and estimating arc-wise constant empirical accelerations in along track direction. The overlap analysis over the entire investigated time span of 13 months indicates an orbital precision of 13.79 m, 14.17 m, and 1.28 m in along track, cross track, and radial direction, respectively, with 21.32 m in total position. We compare our orbits to the official science orbits released by the US National Aeronautics and Space Administration (NASA). The differences amount to 9.50 m, 6.98 m, and 1.50 m in along track, cross track, and radial direction, respectively, as well as 12.71 m in total position. Based on the reconstructed LRO orbits, we estimated lunar gravity field coefficients up to spherical harmonic degree and order 60. The results are compared to gravity field solutions derived from data collected by other lunar missions.

  11. Simple satellite orbit propagator

    NASA Astrophysics Data System (ADS)

    Gurfil, P.

    2008-06-01

    An increasing number of space missions require on-board autonomous orbit determination. The purpose of this paper is to develop a simple orbit propagator (SOP) for such missions. Since most satellites are limited by the available processing power, it is important to develop an orbit propagator that will use limited computational and memory resources. In this work, we show how to choose state variables for propagation using the simplest numerical integration scheme available-the explicit Euler integrator. The new state variables are derived by the following rationale: Apply a variation-of-parameters not on the gravity-affected orbit, but rather on the gravity-free orbit, and teart the gravity as a generalized force. This ultimately leads to a state vector comprising the inertial velocity and a modified position vector, wherein the product of velocity and time is subtracted from the inertial position. It is shown that the explicit Euler integrator, applied on the new state variables, becomes a symplectic integrator, preserving the Hamiltonian and the angular momentum (or a component thereof in the case of oblateness perturbations). The main application of the proposed propagator is estimation of mean orbital elements. It is shown that the SOP is capable of estimating the mean elements with an accuracy that is comparable to a high-order integrator that consumes an order-of-magnitude more computational time than the SOP.

  12. The Eccentric Behavior of Nearly Frozen Orbits

    NASA Technical Reports Server (NTRS)

    Sweetser, Theodore H.; Vincent, Mark A.

    2013-01-01

    Frozen orbits are orbits which have only short-period changes in their mean eccentricity and argument of periapse, so that they basically keep a fixed orientation within their plane of motion. Nearly frozen orbits are those whose eccentricity and argument of periapse have values close to those of a frozen orbit. We call them "nearly" frozen because their eccentricity vector (a vector whose polar coordinates are eccentricity and argument of periapse) will stay within a bounded distance from the frozen orbit eccentricity vector, circulating around it over time. For highly inclined orbits around the Earth, this distance is effectively constant over time. Furthermore, frozen orbit eccentricity values are low enough that these orbits are essentially eccentric (i.e., off center) circles, so that nearly frozen orbits around Earth are bounded above and below by frozen orbits.

  13. GLONASS orbit/clock combination in VNIIFTRI

    NASA Astrophysics Data System (ADS)

    Bezmenov, I.; Pasynok, S.

    2015-08-01

    An algorithm and a program for GLONASS satellites orbit/clock combination based on daily precise orbits submitted by several Analytic Centers were developed. Some theoretical estimates for combine orbit positions RMS were derived. It was shown that under condition that RMS of satellite orbits provided by the Analytic Centers during a long time interval are commensurable the RMS of combine orbit positions is no greater than RMS of other satellite positions estimated by any of the Analytic Centers.

  14. Saturn orbiter mission study

    NASA Technical Reports Server (NTRS)

    Wells, W. C.; Sullivan, R. J.

    1973-01-01

    A preliminary analysis of the important aspects of missions orbiting the planet Saturn is provided. Orbital missions to Saturn is given serious consideration for the 1980's, or after flybys by Pioneer 10/G and Mariner Jupiter-Saturn 1977. An attempt is made to characterize Saturn orbiters in detail so that comparisons with Jupiter missions can be made. The scientific objectives of Saturn exploration are grouped under four topics: (1) the atmosphere, (2) the magnetosphere, (3) the rings, and (4) the satellites.

  15. The Mars Reconnaissance Orbiter Mission: From Launch to the Primary Science Orbit

    NASA Technical Reports Server (NTRS)

    Johnston, Martin D.; Graf, James E.; Zurek, Richard W.; Eisen, Howard J.; Jai, Benhan; Erickson, James K.

    2007-01-01

    The Mars Reconnaissance Orbiter (MRO) was launched from Cape Canaveral Air Force Station, Florida, USA, aboard an Atlas V-401 launch vehicle on August 12, 2005. The MRO spacecraft carries a very sophisticated scientific payload. Its primary science mission is to to provide global, regional survey, and targeted observations from a low altitude orbit for one Martian year (687 Earth days). After a seven month interplanetary transit, the spacecraft fired its six main engines and established a highly elliptical capture orbit at Mars. During the post-MOI early check-out period, four instruments acquired engineering-quality data. This was followed by five months of aerobraking operations. After aerobraking was terminated, a series of propulsive maneuvers were used to establish the desired low altitude science orbit. As the spacecraft is readied for its primary science mission, spacecraft and instrument checkout and deployment activities have continued.

  16. A case report of orbital Langerhans cell histiocytosis presenting as a orbital cellulitis.

    PubMed

    Albert-Fort, M; González-Candial, M

    2018-04-08

    A 10-year-old girl was seen with a 3-week history of right upper lid swelling and with no other symptoms or fever. There was no recent history of sinusitis, trauma, or previous infection involving the periorbital area, or response to oral antibiotic treatment. Orbital computed tomography showed a lesion involving the upper margin of the orbit, and bone destruction at the orbital roof. Biopsy performed revealed the presence of Langerhans cell Histiocytosis. The lesion was surgically debulked and corticosteroids were used intra-operatively. The lesion responded to treatment. The orbital involvement of Langerhans cell histiocytosis, despite its low incidence, should be considered in the examination of acute peri-orbital swelling. It usually presents as an osteolytic lesion, and it is confirmed with a histological examination and immunohistochemical techniques for CD1a and S100. An interdisciplinary approach is recommended to rule out multifocal or multisystemic diseases, as well as to develop an appropriate treatment strategy. Copyright © 2018 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Orbit determination support of the Ocean Topography Experiment (TOPEX)/Poseidon operational orbit

    NASA Technical Reports Server (NTRS)

    Schanzle, A. F.; Rovnak, J. E.; Bolvin, D. T.; Doll, C. E.

    1993-01-01

    The Ocean Topography Experiment (TOPEX/Poseidon) mission is designed to determine the topography of the Earth's sea surface over a 3-year period, beginning shortly after launch in July 1992. TOPEX/Poseidon is a joint venture between the United States National Aeronautics and Space Administration (NASA) and the French Centre Nationale d'Etudes Spatiales. The Jet Propulsion Laboratory is NASA's TOPEX/Poseidon project center. The Tracking and Data Relay Satellite System (TDRSS) will nominally be used to support the day-to-day orbit determination aspects of the mission. Due to its extensive experience with TDRSS tracking data, the NASA Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) will receive and process TDRSS observational data. To fulfill the scientific goals of the mission, it is necessary to achieve and maintain a very precise orbit. The most stringent accuracy requirements are associated with planning and evaluating orbit maneuvers, which will place the spacecraft in its mission orbit and maintain the required ground track. To determine if the FDF can meet the TOPEX/Poseidon maneuver accuracy requirements, covariance analysis was undertaken with the Orbit Determination Error Analysis System (ODEAS). The covariance analysis addressed many aspects of TOPEX/Poseidon orbit determination, including arc length, force models, and other processing options. The most recent analysis has focused on determining the size of the geopotential field necessary to meet the maneuver support requirements. Analysis was undertaken with the full 50 x 50 Goddard Earth Model (GEM) T3 field as well as smaller representations of this model.

  18. Quantitative evaluation of orbital hybridization in carbon nanotubes under radial deformation using π-orbital axis vector

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

    Ohnishi, Masato, E-mail: masato.ohnishi@rift.mech.tohoku.ac.jp; Suzuki, Ken; Miura, Hideo, E-mail: hmiura@rift.mech.tohoku.ac.jp

    2015-04-15

    When a radial strain is applied to a carbon nanotube (CNT), the increase in local curvature induces orbital hybridization. The effect of the curvature-induced orbital hybridization on the electronic properties of CNTs, however, has not been evaluated quantitatively. In this study, the strength of orbital hybridization in CNTs under homogeneous radial strain was evaluated quantitatively. Our analyses revealed the detailed procedure of the change in electronic structure of CNTs. In addition, the dihedral angle, the angle between π-orbital axis vectors of adjacent atoms, was found to effectively predict the strength of local orbital hybridization in deformed CNTs.

  19. On-Orbit Compressor Technology Program

    NASA Technical Reports Server (NTRS)

    Deffenbaugh, Danny M.; Svedeman, Steven J.; Schroeder, Edgar C.; Gerlach, C. Richard

    1990-01-01

    A synopsis of the On-Orbit Compressor Technology Program is presented. The objective is the exploration of compressor technology applicable for use by the Space Station Fluid Management System, Space Station Propulsion System, and related on-orbit fluid transfer systems. The approach is to extend the current state-of-the-art in natural gas compressor technology to the unique requirements of high-pressure, low-flow, small, light, and low-power devices for on-orbit applications. This technology is adapted to seven on-orbit conceptual designs and one prototype is developed and tested.

  20. Similarity in Bilateral Isolated Internal Orbital Fractures.

    PubMed

    Chen, Hung-Chang; Cox, Jacob T; Sanyal, Abanti; Mahoney, Nicholas R

    2018-04-13

    In evaluating patients sustaining bilateral isolated internal orbital fractures, the authors have observed both similar fracture locations and also similar expansion of orbital volumes. In this study, we aim to investigate if there is a propensity for the 2 orbits to fracture in symmetrically similar patterns when sustaining similar trauma. A retrospective chart review was performed studying all cases at our institution of bilateral isolated internal orbital fractures involving the medial wall and/or the floor at the time of presentation. The similarity of the bilateral fracture locations was evaluated using the Fisher's exact test. The bilateral expanded orbital volumes were analyzed using the Wilcoxon signed-rank test to assess for orbital volume similarity. Twenty-four patients with bilateral internal orbital fractures were analyzed for fracture location similarity. Seventeen patients (70.8%) had 100% concordance in the orbital subregion fractured, and the association between the right and the left orbital fracture subregion locations was statistically significant (P < 0.0001). Fifteen patients were analyzed for orbital volume similarity. The average orbital cavity volume was 31.2 ± 3.8 cm on the right and 32.0 ± 3.7 cm on the left. There was a statistically significant difference between right and left orbital cavity volumes (P = 0.0026). The data from this study suggest that an individual who suffers isolated bilateral internal orbital fractures has a statistically significant similarity in the location of their orbital fractures. However, there does not appear to be statistically significant similarity in the expansion of the orbital volumes in these patients.

  1. Sun-Earth L1 Region Halo-To-Halo Orbit and Halo-To-LisaJous Orbit Transfers

    NASA Technical Reports Server (NTRS)

    Roberts, Craig E.; DeFazio, Robert

    2004-01-01

    Practical techniques for designing transfer trajectories between Libration Point Orbits (LPOs) are presented. Motivation for development of these techniques was provided by a hardware contingency experienced by the Solar Heliospheric Observatory (SOHO), a joint mission of the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) orbiting the L1 point of the Sun-Earth system. A potential solution to the problem involved a transfer from SOHO s periodic halo orbit to a new LPO of substantially different dimensions. Assuming the SOHO halo orbit as the departure orbit, several practical LPO transfer techniques were developed to obtain new Lissajous or periodic halo orbits that satisfy mission requirements and constraints. While not implemented for the SOHO mission, practical LPO transfer techniques were devised that are generally applicable to current and future LPO missions.

  2. Orbital Debris and NASA's Measurement Program

    NASA Astrophysics Data System (ADS)

    Africano, J. L.; Stansbery, E. G.

    2002-05-01

    Since the launch of Sputnik in 1957, the number of manmade objects in orbit around the Earth has dramatically increased. The United States Space Surveillance Network (SSN) tracks and maintains orbits on over nine thousand objects down to a limiting diameter of about ten centimeters. Unfortunately, active spacecraft are only a small percentage ( ~ 7%) of this population. The rest of the population is orbital debris or ``space junk" consisting of expended rocket bodies, dead payloads, bits and pieces from satellite launches, and fragments from satellite breakups. The number of these smaller orbital debris objects increases rapidly with decreasing size. It is estimated that there are at least 130,000 orbital debris objects between one and ten centimeters in diameter. Most objects smaller than 10 centimeters go untracked! As the orbital debris population grows, the risk to other orbiting objects, most importantly manned space vehicles, of a collision with a piece of debris also grows. The kinetic energy of a solid 1 cm aluminum sphere traveling at an orbital velocity of 10 km/sec is equivalent to a 400 lb. safe traveling at 60 mph. Fortunately, the volume of space in which the orbiting population resides is large, collisions are infrequent, but they do occur. The Space Shuttle often returns to earth with its windshield pocked with small pits or craters caused by collisions with very small, sub-millimeter-size pieces of debris (paint flakes, particles from solid rocket exhaust, etc.), and micrometeoroids. To get a more complete picture of the orbital-debris environment, NASA has been using both radar and optical techniques to monitor the orbital debris environment. This paper gives an overview of the orbital debris environment and NASA's measurement program.

  3. Orbital structure in oscillating galactic potentials

    NASA Astrophysics Data System (ADS)

    Terzić, Balša; Kandrup, Henry E.

    2004-01-01

    Subjecting a galactic potential to (possibly damped) nearly periodic, time-dependent variations can lead to large numbers of chaotic orbits experiencing systematic changes in energy, and the resulting chaotic phase mixing could play an important role in explaining such phenomena as violent relaxation. This paper focuses on the simplest case of spherically symmetric potentials subjected to strictly periodic driving with the aim of understanding precisely why orbits become chaotic and under what circumstances they will exhibit systematic changes in energy. Four unperturbed potentials V0(r) were considered, each subjected to a time dependence of the form V(r, t) =V0(r)(1 +m0 sinωt). In each case, the orbits divide clearly into regular and chaotic, distinctions which appear absolute. In particular, transitions from regularity to chaos are seemingly impossible. Over finite time intervals, chaotic orbits subdivide into what can be termed `sticky' chaotic orbits, which exhibit no large-scale secular changes in energy and remain trapped in the phase-space region where they started; and `wildly' chaotic orbits, which do exhibit systematic drifts in energy as the orbits diffuse to different phase-space regions. This latter distinction is not absolute, transitions corresponding apparently to orbits penetrating a `leaky' phase-space barrier. The three different orbit types can be identified simply in terms of the frequencies for which their Fourier spectra have the most power. An examination of the statistical properties of orbit ensembles as a function of driving frequency ω allows us to identify the specific resonances that determine orbital structure. Attention focuses also on how, for fixed amplitude m0, such quantities as the mean energy shift, the relative measure of chaotic orbits and the mean value of the largest Lyapunov exponent vary with driving frequency ω and how, for fixed ω, the same quantities depend on m0.

  4. The globe and orbit in Laron syndrome.

    PubMed

    Kornreich, L; Konen, O; Lilos, P; Laron, Z

    2011-09-01

    Patients with LS have an inborn growth hormone resistance, resulting in failure to generate IGF-1. The purpose of this study was to evaluate the size of the eye and orbit in LS. We retrospectively reviewed the MR imaging of the brain in 9 patients with LS for the following parameters: axial diameter of the globe, interzygomatic distance, perpendicular distance from the interzygomatic line to margins of the globe, medial-to-lateral diameter of the orbit at the anterior orbital rim, distance from the anterior orbital rim to the anterior globe, maximal distance between the medial walls of the orbits, lateral orbital wall angle, lateral orbital wall length, and mediolateral thickness of the intraorbital fat in the most cranial image of the orbit. All measurements were made bilaterally. Twenty patients referred for MR imaging for unrelated reasons served as control subjects. Compared with the control group, the patients with LS had a significantly smaller maximal globe diameter and shallower but wider orbits due to a shorter lateral wall, a smaller medial distance between the orbits, and a larger angle of the orbit. The ratio between the most anterior orbital diameter and the globe was greater than that in controls. The position of the globe was more anterior in relation to the interzygomatic line. Shallow and wide orbits and small globes relative to orbital size are seen in LS and may be secondary to IGF-1 deficiency.

  5. Orbit orientation in didelphid marsupials (Didelphimorphia: Didelphidae)

    PubMed Central

    Pilatti, Patricia

    2017-01-01

    Abstract Usually considered a morphologically conservative group, didelphid marsupials present considerable variation in ecology and body size, some of which were shown to relate to morphological structures. Thus, changes on orbit morphology are likely and could be related to that variation. We calculated orbit orientation in 873 specimens of 16 Didelphidae genera yielding estimates of orbits convergence (their position relative to midsagittal line) and verticality (their position relative to frontal plane). We then compared similarities in these variables across taxa to ecological, morphological and phylogenetic data to evaluate the influencing factors on orbit orientation in didelphids. We found an inverse relation between convergence and verticality. Didelphids orbits have low verticality but are highly convergent, yet orbit orientation differs significantly between taxa, and that variation is related to morphological aspects of the cranium. Rostral variables are the only morphological features correlated with orbit orientation: increasing snout length yields more convergent orbits, whereas increase on snout breadth imply in more vertical orbits. Size and encephalization quotients are uncorrelated with orbit orientation. Among ecological data, diet showed significant correlation whereas locomotion is the factor that less affects the position of orbits. Phylogeny is uncorrelated to any orbital parameters measured. Ecological factors seemingly play a more important role on orbit orientation than previously expected, and differentiation on orbit orientation seems to be more functional than inherited. Thus, despite the apparent homogeneity on didelphid morphology, there is subtle morphological variability that may be directly related to feeding behavior. PMID:29492000

  6. Mars Observer trajectory and orbit design

    NASA Technical Reports Server (NTRS)

    Beerer, Joseph G.; Roncoli, Ralph B.

    1991-01-01

    The Mars Observer launch, interplanetary, Mars orbit insertion, and mapping orbit designs are described. The design objective is to enable a near-maximum spacecraft mass to be placed in orbit about Mars. This is accomplished by keeping spacecraft propellant requirements to a minimum, selecting a minimum acceptable launch period, equalizing the spacecraft velocity change requirement at the beginning and end of the launch period, and constraining the orbit insertion maneuvers to be coplanar. The mapping orbit design objective is to provide the opportunity for global observation of the planet by the science instruments while facilitating the spacecraft design. This is realized with a sun-synchronous near-polar orbit whose ground-track pattern covers the planet at progressively finer resolution.

  7. Perturbations of Cometary Orbits

    DTIC Science & Technology

    1961-01-01

    calculations are based on the energy changes as the comet describes a parabolic orbit. If E is the energy per unit mass of a comet in describing a...parabolic orbit about the sun, then the change in the energy bE for a complete orbit will be calculated. A sufficient gain in energy to make E positive...change in energy we will assume that Jupiter is the only planet that has a significant effect. S \\ G it FIGURRE 1 Comet in relation to sun and Jupiter. The

  8. Stereotactic radiosurgery for the treatment of symptomatic brainstem cavernous malformations.

    PubMed

    Monaco, Edward A; Khan, Aftab A; Niranjan, Ajay; Kano, Hideyuki; Grandhi, Ramesh; Kondziolka, Douglas; Flickinger, John C; Lunsford, L Dade

    2010-09-01

    The authors performed a retrospective review of prospectively collected data to evaluate the safety and efficacy of stereotactic radiosurgery (SRS) for the treatment of patients harboring symptomatic solitary cavernous malformations (CMs) of the brainstem that bleed repeatedly and are high risk for resection. Between 1988 and 2005, 68 patients (34 males and 34 females) with solitary, symptomatic CMs of the brainstem underwent Gamma Knife surgery. The mean patient age was 41.2 years, and all patients had suffered at least 2 symptomatic hemorrhages (range 2-12 events) before radiosurgery. Prior to SRS, 15 patients (22.1%) had undergone attempted resection. The mean volume of the malformation treated was 1.19 ml, and the mean prescribed marginal radiation dose was 16 Gy. The mean follow-up period was 5.2 years (range 0.6-12.4 years). The pre-SRS annual hemorrhage rate was 32.38%, or 125 hemorrhages, excluding the first hemorrhage, over a total of 386 patient-years. Following SRS, 11 hemorrhages were observed within the first 2 years of follow-up (8.22% annual hemorrhage rate) and 3 hemorrhages were observed in the period after the first 2 years of follow-up (1.37% annual hemorrhage rate). A significant reduction (p < 0.0001) in the risk of brainstem CM hemorrhages was observed following radiosurgical treatment, as well as in latency period of 2 years after SRS (p < 0.0447). Eight patients (11.8%) experienced new neurological deficits as a result of adverse radiation effects following SRS. The results of this study support a role for the use of SRS for symptomatic CMs of the brainstem, as it is relatively safe and appears to reduce rebleeding rates in this high-surgical-risk location.

  9. Laser Ranging to the Lunar Reconnaissance Orbiter: improved timing and orbits

    NASA Astrophysics Data System (ADS)

    Mao, D.; Mcgarry, J.; Sun, X.; Torrence, M. H.; Skillman, D.; Hoffman, E.; Mazarico, E.; Rowlands, D. D.; Golder, J.; Barker, M. K.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

    2013-12-01

    The Laser ranging (LR) experiment to the Lunar Reconnaissance Orbiter (LRO) has been under operation for more than 4 years, since the launch of the spacecraft in June 2009. Led by NASA's Next Generation Satellite Laser Ranging(NGSLR) station at Greenbelt, Maryland, ten laser ranging stations over the world have been participating in the experiment and have collected over 3,200 hours of ranging data. These range measurements are used to monitor the behavior of the LRO clock and to generate orbital solutions for LRO. To achieve high-quality results in range, ground stations like NGSLR are using H-maser clocks to obtain a stable and continuous time baseline for the orbit solutions. An All-View GPS receiver was included at NGSLR since January 2013 which monitors the H-maser time against the master clock at the United State Naval Observatory (USNO) via the GPS satellites. NGSLR has successfully established nano-second level epoch time accuracy and 10-15 clock stability since then. Time transfer experiments using LRO as a common receiver have been verified in ground testing between NGSLR and MOBLAS7 via a ground terminal with a Lunar Orbiter Laser Altimeter (LOLA)-like receiver at Greenbelt, Maryland. Two hour-long ground tests using a LOLA-like detector and two different ground targets yielded results consistent with each other, and those from the previous 10-minute test completed one year ago. Time transfer tests between NGSLR and MOBLAS7 via LRO are ongoing. More time transfer tests are being planned from NGSLR to McDonald Laser Ranging Station (MLRS) in Texas and later from NGSLR to European satellite laser ranging (SLR) stations. Upon the completion of these time transfer experiments, nanosecond-level epoch time accuracy will be brought to stations besides NGSLR, and such high precision of the ground time can contribute to the LRO precision orbit determination (POD) process. Presently, by using the high-resolution GRAIL gravity models, the LRO orbits determined from

  10. The family of planar periodic orbits generated by the equal-mass four-body Schubart interplay orbit

    NASA Astrophysics Data System (ADS)

    Chopovda, Valerie; Sweatman, Winston L.

    2018-05-01

    We locate members of a one-parameter family of equal-mass four-body periodic orbits in the plane. The family begins and ends with the rectilinear four-body equal-mass Schubart interplay orbit and passes through a double choreography orbit. The first-order stability of these orbits is computed. Some members of this symmetric family are stable to symmetric perturbations; however, they are unstable when all perturbations are allowed.

  11. Trial Readiness in Cavernous Angiomas With Symptomatic Hemorrhage (CASH).

    PubMed

    Polster, Sean P; Cao, Ying; Carroll, Timothy; Flemming, Kelly; Girard, Romuald; Hanley, Daniel; Hobson, Nicholas; Kim, Helen; Koenig, James; Koskimäki, Janne; Lane, Karen; Majersik, Jennifer J; McBee, Nichol; Morrison, Leslie; Shenkar, Robert; Stadnik, Agnieszka; Thompson, Richard E; Zabramski, Joseph; Zeineddine, Hussein A; Awad, Issam A

    2018-04-11

    Brain cavernous angiomas with symptomatic hemorrhage (CASH) are uncommon but exact a heavy burden of neurological disability from recurrent bleeding, for which there is no proven therapy. Candidate drugs to stabilize the CASH lesion and prevent rebleeding will ultimately require testing of safety and efficacy in multisite clinical trials. Much progress has been made in understanding the epidemiology of CASH, and novel biomarkers have been linked to the biological mechanisms and clinical activity in lesions. Yet, the ability to enroll and risk-stratify CASH subjects has never been assessed prospectively at multiple sites. Biomarkers and other outcomes have not been evaluated for their sensitivity and reliability, nor have they been harmonized across sites. To address knowledge gaps and establish a research network as infrastructure for future clinical trials, through the Trial Readiness grant mechanism, funded by National Institute of Neurological Disorders and Stroke/National Institutes of Health. This project includes an observational cohort study to assess (1) the feasibility of screening, enrollment rates, baseline disease categorization, and follow-up of CASH using common data elements at multiple sites, (2) the reliability of imaging biomarkers including quantitative susceptibility mapping and permeability measures that have been shown to correlate with lesion activity, and (3) the rates of recurrent hemorrhage and change in functional status and biomarker measurements during prospective follow-up. We propose a harmonized multisite assessment of enrollment rates of CASH, baseline features relevant to stratification in clinical trials, and follow-up assessments of functional outcomes in relation to clinical bleeds. We introduce novel biomarkers of vascular leak and hemorrhage, with firm mechanistic foundations, which have been linked to clinical disease activity. We shall test their reliability and validity at multiple sites, and assess their changes over time

  12. Embolization of direct carotid cavernous fistulas with the novel double-balloon technique

    PubMed Central

    Niu, Yin; Li, Lin; Tang, Jun; Zhu, Gang

    2015-01-01

    Multiple endovascular management of direct carotid cavernous fistula (CCF) has been widely accepted as a treatment option. Embolization of the fistula with detachable balloons or thrombogenic coil-based occlusion has been the main choice to treat direct CCF, with good safety and efficacy. This study investigated the safety and efficacy of embolization of direct CCF with the novel double-balloon technique. A retrospective review of a prospective database on cerebral vascular disease was performed. We identified a total of five patients presenting with high-flow direct CCF. All patients were managed with transarterial embolization with the novel double-balloon technique. Three of the five patients were treated with two detachable balloons, and a completely occluded fistula with preservation of the internal carotid artery was achieved. Of the remaining two patients treated with more detachable balloons, one patient achieved a perfect outcome and the other one suffered from recurrent fistula due to balloon migration 3 weeks after embolization. During a follow-up period of 12–18 months, no symptoms reoccurred in any patient. Thus, the double-balloon treatment may be a promising method for CCF complete occlusion. This novel technique may bring more benefits in the following two cases: 1). A single inflated detachable balloon fails to completely occlude the CCF, which causing the next balloon can not pass into the fistula. 2). A giant CCF needs more balloons for fistula embolization. PMID:26586136

  13. Low Earth orbit communications satellite

    NASA Technical Reports Server (NTRS)

    Moroney, D.; Lashbrook, D.; Mckibben, B.; Gardener, N.; Rivers, T.; Nottingham, G.; Golden, B.; Barfield, B.; Bruening, J.; Wood, D.

    1992-01-01

    A current thrust in satellite communication systems considers a low-Earth orbiting constellations of satellites for continuous global coverage. Conceptual design studies have been done at the time of this design project by LORAL Aerospace Corporation under the program name GLOBALSTAR and by Motorola under their IRIDIUM program. This design project concentrates on the spacecraft design of the GLOBALSTAR low-Earth orbiting communication system. Overview information on the program was gained through the Federal Communications Commission licensing request. The GLOBALSTAR system consists of 48 operational satellites positioned in a Walker Delta pattern providing global coverage and redundancy. The operational orbit is 1389 km (750 nmi) altitude with eight planes of six satellites each. The orbital planes are spaced 45 deg., and the spacecraft are separated by 60 deg. within the plane. A Delta 2 launch vehicle is used to carry six spacecraft for orbit establishment. Once in orbit, the spacecraft will utilize code-division multiple access (spread spectrum modulation) for digital relay, voice, and radio determination satellite services (RDSS) yielding position determination with accuracy up to 200 meters.

  14. Transarterial Embolization of a Spontaneous Intraorbital Arteriovenous Fistula With n-BCA Glue.

    PubMed

    Konstas, Angelos A; Rootman, Daniel B; Quiros, Peter A; Ross, Ian B

    Arteriovenous fistulae of the orbit are exceedingly rare. They are high-flow vascular malformations involving a fistula from the ophthalmic artery to one of the draining ophthalmic veins. Presenting symptoms can mimic those of carotid cavernous fistulae or of ophthalmic venous varices, and include diplopia, proptosis, chemosis, decreased visual acuity, and retro-orbital pain. Very few case reports are published on the treatment of this aggressive vascular malformation, and they uniformly describe techniques involving a transvenous access for the embolization of the fistula. To the best of authors' knowledge, they report the first case of transarterial embolization of an intraorbital AVF.

  15. Calculating Statistical Orbit Distributions Using GEO Optical Observations with the Michigan Orbital Debris Survey Telescope (MODEST)

    NASA Technical Reports Server (NTRS)

    Matney, M.; Barker, E.; Seitzer, P.; Abercromby, K. J.; Rodriquez, H. M.

    2006-01-01

    NASA's Orbital Debris measurements program has a goal to characterize the small debris environment in the geosynchronous Earth-orbit (GEO) region using optical telescopes ("small" refers to objects too small to catalog and track with current systems). Traditionally, observations of GEO and near-GEO objects involve following the object with the telescope long enough to obtain an orbit suitable for tracking purposes. Telescopes operating in survey mode, however, randomly observe objects that pass through their field of view. Typically, these short-arc observation are inadequate to obtain detailed orbits, but can be used to estimate approximate circular orbit elements (semimajor axis, inclination, and ascending node). From this information, it should be possible to make statistical inferences about the orbital distributions of the GEO population bright enough to be observed by the system. The Michigan Orbital Debris Survey Telescope (MODEST) has been making such statistical surveys of the GEO region for four years. During that time, the telescope has made enough observations in enough areas of the GEO belt to have had nearly complete coverage. That means that almost all objects in all possible orbits in the GEO and near- GEO region had a non-zero chance of being observed. Some regions (such as those near zero inclination) have had good coverage, while others are poorly covered. Nevertheless, it is possible to remove these statistical biases and reconstruct the orbit populations within the limits of sampling error. In this paper, these statistical techniques and assumptions are described, and the techniques are applied to the current MODEST data set to arrive at our best estimate of the GEO orbit population distribution.

  16. A Comparison of Damaging Meteoroid and Orbital Debris Fluxes in Earth Orbit

    NASA Technical Reports Server (NTRS)

    Cooke, William; Matney, Mark; Moorhead, Althea V.; Vavrin, Andrew

    2017-01-01

    Low Earth orbit is populated with a substantial amount of orbital debris, and it is usually assumed that the flux from these objects contributes to most of the hypervelocity particle risk to spacecraft in this region. The meteoroid flux is known to be dominant at very low altitudes (<300 km), where atmospheric drag rapidly removes debris, and at very high altitudes beyond GEO (geostationary), where debris is practically non-existent. The vagueness of these boundaries has prompted this work, in which we compare the fluxes of meteoroids and orbital debris capable of penetrating a millimeter thick aluminum plate for circular orbits with altitudes ranging from the top of the atmosphere to 100,000 km. The outputs from the latest NASA debris and meteoroid models, ORDEM 3.0 and MEMR2, are combined with the modified Cour-Palais ballistic limit equation to make a realistic evaluation of the damage-capable particle fluxes, thereby establishing the relative contributions of hazardous debris and meteoroids in near Earth space.

  17. Drag De-Orbit Device (D3): A Retractable Device for CubeSat Attitude and Orbit Control using Aerodynamic Forces

    NASA Technical Reports Server (NTRS)

    Guglielmo, David; Omar, Sanny R.; Bevilacqua, Riccardo

    2017-01-01

    The increasing number of CubeSats being launched has raised concerns about orbital debris since most of these satellites have no means of active orbit control. Some technologies exist to increase the surface area of a CubeSat and expedite de-orbit due to aerodynamic drag in low Earth orbit, but most of these devices cannot be retracted and hence cannot be used for orbital maneuvering. This paper discusses the De-Orbit Drag Device (D3) module that is capable of de-orbiting a 12U, 15kg CubeSat from a 700 km circular orbit in under 25 years and can be deployed and retracted to modulate the aerodynamic drag force experienced by the satellite. This facilitates orbital maneuvering using aerodynamic drag and the active targeting of a de-orbit location. In addition, the geometry of this drag device provides 3-axis attitude stabilization of the host CubeSat using aerodynamic and gravity gradient torques which is useful for many missions and provides a predictable aerodynamic profile for use in orbital maneuvering algorithms.

  18. ExoMars/TGO Science Orbit Design

    NASA Technical Reports Server (NTRS)

    Long, Stacia; Lyons, Dan; Guinn, Joe; Lock, Rob

    2012-01-01

    This paper describes the development of the science orbit for the 2016 ESA/NASA collaborative ExoMars/Trace Gas Orbiter (TGO) mission. The initial requirements for the ExoMars/TGO mission simply described the science orbit as circular with a 400 km altitude and a 74 deg inclination. Over the past year, the JPL mission design team worked with the TGO science teams to refine the science orbit requirements and recommend an orbit that would be operationally feasible, easy to maintain, and most important allow the science teams to best meet their objectives.

  19. Discovery Orbiter Major Modifications

    NASA Image and Video Library

    2003-08-27

    During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician moves a circuit reset on the cockpit console. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  20. Orbiter utilization as an ACRV

    NASA Technical Reports Server (NTRS)

    Cruz, Jonathan N.; Heck, Michael L.; Kumar, Renjith R.; Mazanek, Daniel D.; Troutman, Patrick A.

    1990-01-01

    Assuming that a Shuttle Orbiter could be qualified to serve long duration missions attached to Space Station Freedom in the capacity as an Assured Crew Return Vehicle (ACRV), a study was conducted to identify and examine candidate attach locations. Baseline, modified hardware, and new hardware design configurations were considered. Dual simultaneous Orbiter docking accommodation were required. Resulting flight characteristics analyzed included torque equilibrium attitude (TEA), microgravity environment, attitude controllability, and reboost fuel requirements. The baseline Station could not accommodate two Orbiters. Modified hardware configurations analyzed had large TEA's. The utilization of an oblique docking mechanism best accommodated an Orbiter as an ACRV.

  1. OSO-6 Orbiting Solar Observatory

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The description, development history, test history, and orbital performance analysis of the OSO-6 Orbiting Solar Observatory are presented. The OSO-6 Orbiting Solar Observatory was the sixth flight model of a series of scientific spacecraft designed to provide a stable platform for experiments engaged in the collection of solar and celestial radiation data. The design objective was 180 days of orbital operation. The OSO-6 has telemetered an enormous amount of very useful experiment and housekeeping data to GSFC ground stations. Observatory operation during the two-year reporting period was very successful except for some experiment instrument problems.

  2. [Malignant Choroidal Melanoma in T4 Orbital Stage; Prosthesis of the Orbit].

    PubMed

    Furdová, A; Ferková, A; Krásnik, V; Krčová, I; Horkovičová, K

    2015-06-01

    Diagnosis and treatment of tumors of the eye is extremely difficul; surgical treatment in advanced stages, when the tumor grows in the orbit, leads to extensive radical surgery of the face. The extent and nature of surgical procedures depends on the nature of the tumor process, in advanced stages is indicated mutilating surgery--exenteration of the orbit. Exenteration of the orbit due to the extrascleral extension of malignant melanoma of the uvea is very rare, unfortunately, even today in certain cases it is necessary to make such a mutilating surgery. Case report--65 year old female patient, sent to our Departement in 2008 with the finding of the pigment deposits on the posterior pole of the left eye. Ultrasound study found elevations of up to 3 mm, she was asked to come for further control in three months interval. She did not coma, furthermore she sporadically attended another eye clinic. In 2011 she was treated for secondary glaucoma--cyclocryopexia. Due to pain another surgery--tarzoraphia was indicated. In 2012 she underwent surgery at St. Elisabeth Cancer Institute in Bratislava--Nefrectomia transperitoneally l. dx., excision hepatis. Histological examination in addition to the primary papillary renal carcinoma--mucinous tubular T1 Nx Mx type, found the metastasis of malignant melanoma to the liver and right kidney. She underwent the diagnostic procedure to find the origo of the melanoma. The patient was subsequently admitted to our clinic with blind painfull eye for enucleation. During the surgery the was found retrobulbar tumor ingrowth. Histopatholigical findings confirmed malignant melanoma. Indicated was exenteration of the orbit due to malignant melanoma T4 N0 M2 stage in June 2012. After healing of the cavity she was recommended to design an individual prosthesis. After completing several courses of palliative chemotherapy during a recent review in January 2015 the patient is without recurrence of the melanoma in the orbit Histological examination

  3. Cassini orbiter arrives at SLF

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Workers prepare to tow away the large container with the Cassini orbiter from KSC's Shuttle Landing Facility. The orbiter just arrived on the U.S. Air Force C-17 air cargo plane, shown here, from Edwards Air Force Base, California. The orbiter and the Huygens probe already being processed at KSC are the two primary components of the Cassini spacecraft, which will be launched on a Titan IVB/Centaur expendable launch vehicle from Cape Canaveral Air Station. Cassini will explore Saturn, its rings and moons for four years. The Huygens probe, designed and developed for the European Space Agency (ESA), will be deployed from the orbiter to study the clouds, atmosphere and surface of Saturn's largest moon, Titan. The orbiter was designed and assembled at NASA's Jet Propulsion Laboratory in California. Following postflight inspections, integration of the 12 science instruments not already installed on the orbiter will be completed. Then, the parabolic high-gain antenna and the propulsion module will be mated to the orbiter, followed by the Huygens probe, which will complete spacecraft integration. The Cassini mission is targeted for an Oct. 6 launch to begin its 6.7-year journey to the Saturnian system. Arrival at the planet is expected to occur around July 1, 2004.

  4. Spin-orbit scattering visualized in quasiparticle interference

    NASA Astrophysics Data System (ADS)

    Kohsaka, Y.; Machida, T.; Iwaya, K.; Kanou, M.; Hanaguri, T.; Sasagawa, T.

    2017-03-01

    In the presence of spin-orbit coupling, electron scattering off impurities depends on both spin and orbital angular momentum of electrons—spin-orbit scattering. Although some transport properties are subject to spin-orbit scattering, experimental techniques directly accessible to this effect are limited. Here we show that a signature of spin-orbit scattering manifests itself in quasiparticle interference (QPI) imaged by spectroscopic-imaging scanning tunneling microscopy. The experimental data of a polar semiconductor BiTeI are well reproduced by numerical simulations with the T -matrix formalism that include not only scalar scattering normally adopted but also spin-orbit scattering stronger than scalar scattering. To accelerate the simulations, we extend the standard efficient method of QPI calculation for momentum-independent scattering to be applicable even for spin-orbit scattering. We further identify a selection rule that makes spin-orbit scattering visible in the QPI pattern. These results demonstrate that spin-orbit scattering can exert predominant influence on QPI patterns and thus suggest that QPI measurement is available to detect spin-orbit scattering.

  5. Stabilization of VEGFR2 signaling by cerebral cavernous malformation 3 is critical for vascular development.

    PubMed

    He, Yun; Zhang, Haifeng; Yu, Luyang; Gunel, Murat; Boggon, Titus J; Chen, Hong; Min, Wang

    2010-04-06

    Cerebral cavernous malformations (CCMs) are human vascular malformations caused by mutations in three genes of unknown function: CCM1, CCM2, and CCM3. CCM3, also known as PDCD10 (programmed cell death 10), was initially identified as a messenger RNA whose abundance was induced by apoptotic stimuli in vitro. However, the in vivo function of CCM3 has not been determined. Here, we describe mice with a deletion of the CCM3 gene either ubiquitously or specifically in the vascular endothelium, smooth muscle cells, or neurons. Mice with global or endothelial cell-specific deletion of CCM3 exhibited defects in embryonic angiogenesis and died at an early embryonic stage. CCM3 deletion reduced vascular endothelial growth factor receptor 2 (VEGFR2) signaling in embryos and endothelial cells. In response to VEGF stimulation, CCM3 was recruited to and stabilized VEGFR2, and the carboxyl-terminal domain of CCM3 was required for the stabilization of VEGFR2. Indeed, the CCM3 mutants found in human patients lacking the carboxyl-terminal domain were labile and were unable to stabilize and activate VEGFR2. These results demonstrate that CCM3 promotes VEGFR2 signaling during vascular development.

  6. SCIAMACHY In-orbit Operations until 2013

    NASA Astrophysics Data System (ADS)

    Gottwald, Manfred; Krieg, Eckhart; Lichtenberg, Günter; Noël, Stefan; Bramstedt, Klaus; Bovensmann, Heinrich

    In 2010 ENVISAT enters its next mission extension phase when a manoeuvre transfers the plat-form from its nominal into a modified orbit. This modified orbit is not only characterized by the lower altitude but also by slightly drifting parameters such as e.g. the inclination or the Mean Local Solar Time at ascending node crossing. Thus all SCIAMACHY measurements requiring an accurate pointing knowledge are affected. How the line-of-sight evolves along the orbit de-pends on orbit altitude and orbital period. Therefore adjustments to SCIAMACHY's on-board instrument configuration are necessary reflecting this orbit chance. Based on a detailed analysis simulating SCIAMACHY operations in the modified orbit until the end of 2013, the impacts on nadir, limb and solar and lunar occultation measurements when orbiting the Earth at a reduced altitude was studied. By modifying SCIAMACHY's configuration these impacts can be compensated for. Thus the current performance of instrument operations, including the pointing knowledge, can be maintained. It ensures acquisition of high quality measurement data for the entire duration of the mission. This presentation describes how the instrument will be configured for achieving successful operations until the end of 2013. In addition a brief outlook is given how the drifting modified orbit may impact an operations phase even beyond 2013 and potential corrective countermeasures.

  7. Algorithms for Autonomous GPS Orbit Determination and Formation Flying: Investigation of Initialization Approaches and Orbit Determination for HEO

    NASA Technical Reports Server (NTRS)

    Axelrad, Penina; Speed, Eden; Leitner, Jesse A. (Technical Monitor)

    2002-01-01

    This report summarizes the efforts to date in processing GPS measurements in High Earth Orbit (HEO) applications by the Colorado Center for Astrodynamics Research (CCAR). Two specific projects were conducted; initialization of the orbit propagation software, GEODE, using nominal orbital elements for the IMEX orbit, and processing of actual and simulated GPS data from the AMSAT satellite using a Doppler-only batch filter. CCAR has investigated a number of approaches for initialization of the GEODE orbit estimator with little a priori information. This document describes a batch solution approach that uses pseudorange or Doppler measurements collected over an orbital arc to compute an epoch state estimate. The algorithm is based on limited orbital element knowledge from which a coarse estimate of satellite position and velocity can be determined and used to initialize GEODE. This algorithm assumes knowledge of nominal orbital elements, (a, e, i, omega, omega) and uses a search on time of perigee passage (tau(sub p)) to estimate the host satellite position within the orbit and the approximate receiver clock bias. Results of the method are shown for a simulation including large orbital uncertainties and measurement errors. In addition, CCAR has attempted to process GPS data from the AMSAT satellite to obtain an initial estimation of the orbit. Limited GPS data have been received to date, with few satellites tracked and no computed point solutions. Unknown variables in the received data have made computations of a precise orbit using the recovered pseudorange difficult. This document describes the Doppler-only batch approach used to compute the AMSAT orbit. Both actual flight data from AMSAT, and simulated data generated using the Satellite Tool Kit and Goddard Space Flight Center's Flight Simulator, were processed. Results for each case and conclusion are presented.

  8. Altimetry, Orbits and Tides

    NASA Technical Reports Server (NTRS)

    Colombo, O. L.

    1984-01-01

    The nature of the orbit error and its effect on the sea surface heights calculated with satellite altimetry are explained. The elementary concepts of celestial mechanics required to follow a general discussion of the problem are included. Consideration of errors in the orbits of satellites with precisely repeating ground tracks (SEASAT, TOPEX, ERS-1, POSEIDON, amongst past and future altimeter satellites) are detailed. The theoretical conclusions are illustrated with the numerical results of computer simulations. The nature of the errors in this type of orbits is such that this error can be filtered out by using height differences along repeating (overlapping) passes. This makes them particularly valuable for the study and monitoring of changes in the sea surface, such as tides. Elements of tidal theory, showing how these principles can be combined with those pertinent to the orbit error to make direct maps of the tides using altimetry are presented.

  9. RHIC BPM system average orbit calculations

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

    Michnoff,R.; Cerniglia, P.; Degen, C.

    2009-05-04

    RHIC beam position monitor (BPM) system average orbit was originally calculated by averaging positions of 10000 consecutive turns for a single selected bunch. Known perturbations in RHIC particle trajectories, with multiple frequencies around 10 Hz, contribute to observed average orbit fluctuations. In 2006, the number of turns for average orbit calculations was made programmable; this was used to explore averaging over single periods near 10 Hz. Although this has provided an average orbit signal quality improvement, an average over many periods would further improve the accuracy of the measured closed orbit. A new continuous average orbit calculation was developed justmore » prior to the 2009 RHIC run and was made operational in March 2009. This paper discusses the new algorithm and performance with beam.« less

  10. Orbit determination for ISRO satellite missions

    NASA Astrophysics Data System (ADS)

    Rao, Ch. Sreehari; Sinha, S. K.

    Indian Space Research Organisation (ISRO) has been successful in using the in-house developed orbit determination and prediction software for satellite missions of Bhaskara, Rohini and APPLE. Considering the requirements of satellite missions, software packages are developed, tested and their accuracies are assessed. Orbit determination packages developed are SOIP, for low earth orbits of Bhaskara and Rohini missions, ORIGIN and ODPM, for orbits related to all phases of geo-stationary missions and SEGNIP, for drift and geo-stationary orbits. Software is tested and qualified using tracking data of SIGNE-3, D5-B, OTS, SYMPHONIE satellites with the help of software available with CNES, ESA and DFVLR. The results match well with those available from these agencies. These packages have supported orbit determination successfully throughout the mission life for all ISRO satellite missions. Member-Secretary

  11. Orbital Evolution of Jupiter-family Comets

    NASA Astrophysics Data System (ADS)

    Ipatov, S. I.; Mather, J. C.

    2004-05-01

    The orbital evolution of more than 25,000 Jupiter-family comets (JFCs) under the gravitational influence of planets was studied. After 40 Myr one considered object (with initial orbit close to that of Comet 88P) got aphelion distance Q<3.5 AU, and it moved in orbits with semi-major axis a=2.60-2.61 AU, perihelion distance 1.7orbit close to that of Comet 94P) moved in orbits with a=1.95-2.1 AU, q>1.4 AU, Q<2.6 AU, e=0.2-0.3, and i=9-33 deg for 8 Myr (and it had Q<3 AU for 100 Myr). So JFCs can rarely get typical asteroid orbits and move in them for Myrs. In our opinion, it can be possible that Comet 133P (Elst--Pizarro) moving in a typical asteroidal orbit was earlier a JFC and it circulated its orbit also due to non-gravitational forces. JFCs got near-Earth object (NEO) orbits more often than typical asteroidal orbits. A few JFCs got Earth-crossing orbits with a<2 AU and Q<4.2 AU and moved in such orbits for more than 1 Myr (up to tens or even hundreds of Myrs). Three considered former JFCs even got inner-Earth orbits (with Q<0.983 AU) or Aten orbits for Myrs. The probability of a collision of one of such objects, which move for millions of years inside Jupiter's orbit, with a terrestrial planet can be greater than analogous total probability for thousands other objects. Results obtained by the Bulirsch-Stoer method and by a symplectic method were mainly similar (except for probabilities of close encounters with the Sun when they were high). Our results show that the trans-Neptunian belt can provide a significant portion of NEOs, or the number of trans-Neptunian objects migrating inside solar system could be smaller than it was earlier considered, or most of 1-km former trans-Neptunian objects that had got NEO orbits disintegrated into mini-comets and dust during a smaller part of their dynamical lifetimes if these lifetimes are not small. The

  12. Using Mean Orbit Period in Mars Reconnaissance Orbiter Maneuver Design

    NASA Technical Reports Server (NTRS)

    Chung, Min-Kun J.; Menon, Premkumar R.; Wagner, Sean V.; Williams, Jessica L.

    2014-01-01

    Mars Reconnaissance Orbiter (MRO) has provided communication relays for a number of Mars spacecraft. In 2016 MRO is expected to support a relay for NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft. In addition, support may be needed by another mission, ESA's ExoMars EDL Demonstrator Module's (EDM), only 21 days after the InSight coverage. The close proximity of these two events presents a unique challenge to a conventional orbit synchronization maneuver where one deterministic maneuver is executed prior to each relay. Since the two events are close together and the difference in required phasing between InSight and EDM may be up to half an orbit (yielding a large execution error), the downtrack timing error can increase rapidly at the EDM encounter. Thus, a new maneuver strategy that does not require a deterministic maneuver in-between the two events (with only a small statistical cleanup) is proposed in the paper. This proposed strategy rests heavily on the stability of the mean orbital period. The ability to search and set the specified mean period is fundamental in the proposed maneuver design as well as in understanding the scope of the problem. The proposed strategy is explained and its result is used to understand and solve the problem in the flight operations environment.

  13. Space Tourism: Orbital Debris Considerations

    NASA Astrophysics Data System (ADS)

    Mahmoudian, N.; Shajiee, S.; Moghani, T.; Bahrami, M.

    2002-01-01

    Space activities after a phase of research and development, political competition and national prestige have entered an era of real commercialization. Remote sensing, earth observation, and communication are among the areas in which this growing industry is facing competition and declining government money. A project like International Space Station, which draws from public money, has not only opened a window of real multinational cooperation, but also changed space travel from a mere fantasy into a real world activity. Besides research activities for sending man to moon and Mars and other outer planets, space travel has attracted a considerable attention in recent years in the form of space tourism. Four countries from space fairing nations are actively involved in the development of space tourism. Even, nations which are either in early stages of space technology development or just beginning their space activities, have high ambitions in this area. This is worth noting considering their limited resources. At present, trips to space are available, but limited and expensive. To move beyond this point to generally available trips to orbit and week long stays in LEO, in orbital hotels, some of the required basic transportations, living requirements, and technological developments required for long stay in orbit are already underway. For tourism to develop to a real everyday business, not only the price has to come down to meaningful levels, but also safety considerations should be fully developed to attract travelers' trust. A serious hazard to space activities in general and space tourism in particular is space debris in earth orbit. Orbiting debris are man-made objects left over by space operations, hazardous to space missions. Since the higher density of debris population occurs in low earth orbit, which is also the same orbit of interest to space tourism, a careful attention should be paid to the effect of debris on tourism activities. In this study, after a

  14. Nongyrotropic electron orbits in collisionless magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Zenitani, S.

    2016-12-01

    In order to study inner workings of magnetic reconnection, NASA has recently launched Magnetospheric MultiScale (MMS) spacecraft. It is expected to observe electron velocity distribution functions (VDFs) at high resolution in magnetotail reconnection sites in 2017. Since VDFs are outcomes of many particle orbits, it is important to understand the relation between electron orbits and VDFs. In this work, we study electron orbits and associated VDFs in the electron current layer in magnetic reconnection, by using a two-dimensional particle-in-cell (PIC) simulation. By analyzing millions of electron orbits, we discover several new orbits: (1) Figure-eight-shaped regular orbits inside the super-Alfvenic electron jet, (2) noncrossing Speiser orbits that do not cross the midplane, (3) noncrossing regular orbits on the jet flanks, and (4) nongyrotropic electrons in the downstream of the jet termination region. Properties of these orbits are organized by a theory on particle orbits (Buchner & Zelenyi 1989 JGR). The noncrossing orbits are mediated by the polarization electric field (Hall electric field E_z) near the midplane. These orbits can be understood as electrostatic extensions of the conventional theory. Properties of the super-Alfvenic electron jet are attributed to the traditional Speiser-orbit electrons. On the other hand, the noncrossing electrons are the majority in number density in the jet flanks. This raise a serious question to our present understanding of physics of collisionless magnetic reconnection, which only assumes crossing populations. We will also discuss spatial distribution of energetic electrons and observational signatures of noncrossing electrons. Reference: Zenitani & Nagai (2016), submitted to Phys. Plasmas.

  15. Masquerading Orbital Abscess Following Attempted Hydrogel Scleral Buckle Removal: Diagnostic Value of Orbital Magnetic Resonance Spectroscopy.

    PubMed

    Pakdel, Farzad; Hadizadeh, Homayoun; Pirmarzdashty, Niloofar; Kiavash, Victoria

    2015-01-01

    A 59-year-old patient developed acute proptosis, peri-orbital swelling and restriction of ocular movements 2 days after attempted scleral buckle removal. Initial clinical and orbital MRI findings were suggestive for orbital cellulitis and orbital abscess. Empiric intravenous antibiotics were not effective. Proton magnetic resonance spectroscopy (MRS) revealed a distinctive composition and helped rule out suppurative and neoplastic processes. The patient recovered soon after removing clear liquefied and tiny particles of the hydrogel buckle by an effective peristaltic technique.

  16. Independent Orbiter Assessment (IOA): Assessment of the Orbiter Experiment (OEX) subsystem

    NASA Technical Reports Server (NTRS)

    Compton, J. M.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Orbiter Experiments (OEX) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison for the Orbiter OEX hardware are documented. The IOA product for the OEX analysis consisted of 82 failure mode worksheets that resulted in two potential critical items being identified.

  17. Complications and outcomes of grafting of posterior orbital fat into the lower lid-cheek junction during orbital decompression.

    PubMed

    Litwin, Andre S; Poitelea, Cornelia; Tan, Petrina; Ziahosseini, Kimia; Malhotra, Raman

    2018-04-01

    To report the complications of grafting of excised posterior orbital fat into the lower lid-cheek junction at the time of orbital decompression surgery. Retrospective review of consecutive patients undergoing orbital decompression combined with grafting of posterior orbital fat to the pre-malar and lateral canthal area (FG). A second group of consecutive patients undergoing orbital decompression but no orbital fat grafting (NoFG) were also studied as a form of comparative control. Standard patient data, including age, sex, visual acuity, degree of proptosis, operative details, diplopia or any other complications was collected. Independent assessment of pre- and post-operative photographs graded the lower lid-cheek junction. Thirty-four orbits of 29 patients, of which 21 orbits underwent orbital decompression with orbital fat grafting (FG). There were no intraoperative complications, postoperative infections, or visual loss. Complications relating to fat grafting included prolonged swelling in 3 (17%) patients at 3 months, in 1 case lasting 6 months, lower lid lumps in 3 (17%), and fat seepage in 1 (6%). The FG group achieved a greater improvement in the appearance of the lower-lid-cheek junction at 12 months in comparison to NoFG. Mean grade improvement 1.24 ± 1.09 vs 0 ± 0.82 (p = 0.025). Median follow-up was 20 months (range 6-30 months). Grafting of excised orbital fat during orbital decompression can improve the appearance of the lower lid-cheek junction in patients being treated for thyroid orbitopathy. However, 24% of patients will experience swelling and/or lumpiness requiring several months to settle or further fat excision.

  18. Orbiter Docking System Installation

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Workers in Orbiter Processing Facility Bay 3 are installing the Orbiter Docking System (ODS) in the payload bay of the orbiter Atlantis (OV-104). The ODS includes an airlock, a supporting truss structure, a docking base, and a Russian-built docking mechanism (uppermost). The ODS is nearly 15 feet (4.6 meters) wide, 6.5 feet (2 meters) long, 13.5 feet (4.1 meters high), and weighs more than 3,500 pounds (1,588 kilograms). It is being installed near the forward end of the orbiter's payload bay and will be connected by a short tunnel to the existing airlock inside the orbiter's pressurized crew cabin.The installation will take about two hours to complete. Later this week, the Spacelab module also will be installed in OV-104's payload bay; it will connect to the ODS via a tunnel. During the first docking between the Space Shuttle Atlantis and the Russian Space Station Mir, the Russian-built docking mechanism on the ODS will be mated to a similar interface on the Krystall module docking port on Mir, allowing crew members to pass back and forth between the two spacecraft. That Shuttle mission, STS-71, is scheduled for liftoff in early June.

  19. Mission Design for the Lunar Reconnaissance Orbiter

    NASA Technical Reports Server (NTRS)

    Beckman, Mark

    2007-01-01

    The Lunar Reconnaissance Orbiter (LRO) will be the first mission under NASA's Vision for Space Exploration. LRO will fly in a low 50 km mean altitude lunar polar orbit. LRO will utilize a direct minimum energy lunar transfer and have a launch window of three days every two weeks. The launch window is defined by lunar orbit beta angle at times of extreme lighting conditions. This paper will define the LRO launch window and the science and engineering constraints that drive it. After lunar orbit insertion, LRO will be placed into a commissioning orbit for up to 60 days. This commissioning orbit will be a low altitude quasi-frozen orbit that minimizes stationkeeping costs during commissioning phase. LRO will use a repeating stationkeeping cycle with a pair of maneuvers every lunar sidereal period. The stationkeeping algorithm will bound LRO altitude, maintain ground station contact during maneuvers, and equally distribute periselene between northern and southern hemispheres. Orbit determination for LRO will be at the 50 m level with updated lunar gravity models. This paper will address the quasi-frozen orbit design, stationkeeping algorithms and low lunar orbit determination.

  20. Plasma Flowfields Around Low Earth Orbit Objects: Aerodynamics to Underpin Orbit Predictions

    NASA Astrophysics Data System (ADS)

    Capon, Christopher; Boyce, Russell; Brown, Melrose

    2016-07-01

    Interactions between orbiting bodies and the charged space environment are complex. The large variation in passive body parameters e.g. size, geometry and materials, makes the plasma-body interaction in Low Earth Orbit (LEO) a region rich in fundamental physical phenomena. The aerodynamic interaction of LEO orbiting bodies with the neutral environment constitutes the largest non-conservative force on the body. However in general, study of the LEO plasma-body interaction has not been concerned with external flow physics, but rather with the effects on surface charging. The impact of ionospheric flow physics on the forces on space debris (and active objects) is not well understood. The work presented here investigates the contribution that plasma-body interactions have on the flow structure and hence on the total atmospheric force vector experienced by a polar orbiting LEO body. This work applies a hybrid Particle-in-Cell (PIC) - Direct Simulation Monte Carlo (DSMC) code, pdFoam, to self-consistently model the electrostatic flowfield about a cylinder with a uniform, fixed surface potential. Flow conditions are representative of the mean conditions experienced by the Earth Observing Satellite (EOS) based on the International Reference Ionosphere model (IRI-86). The electron distribution function is represented by a non-linear Boltzmann electron fluid and ion gas-surface interactions are assumed to be that of a neutralising, conducting, thermally accommodating solid wall with diffuse reflections. The variation in flowfield and aerodynamic properties with surface potential at a fixed flow condition is investigated, and insight into the relative contributions of charged and neutral species to the flow physics experienced by a LEO orbiting body is provided. This in turn is intended to help improve the fidelity of physics-based orbit predictions for space debris and other near-Earth space objects.

  1. Orbital and Landing Operations at Near-Earth

    NASA Technical Reports Server (NTRS)

    Scheeres, D. J.

    1995-01-01

    Orbital and landing operations about near-Earth asteroids are different than classical orbital operations about large bodies. The major differences lie with the small mass of the asteroid, the lower orbital velocities, the larger Solar tide and radiation pressure perturbations, the irregular shape of the asteroid and the potential for non-uniform rotation of the asteroid. These differences change the nature of orbits about an asteroid to where it is often common to find trajectories that evolve from stable, near-circular orbits to crashing or escaping orbits in a matter of days. The understanding and control of such orbits is important if a human or robotic presence at asteroids is to be commonplace in the future.

  2. Metrics in Keplerian orbits quotient spaces

    NASA Astrophysics Data System (ADS)

    Milanov, Danila V.

    2018-03-01

    Quotient spaces of Keplerian orbits are important instruments for the modelling of orbit samples of celestial bodies on a large time span. We suppose that variations of the orbital eccentricities, inclinations and semi-major axes remain sufficiently small, while arbitrary perturbations are allowed for the arguments of pericentres or longitudes of the nodes, or both. The distance between orbits or their images in quotient spaces serves as a numerical criterion for such problems of Celestial Mechanics as search for common origin of meteoroid streams, comets, and asteroids, asteroid families identification, and others. In this paper, we consider quotient sets of the non-rectilinear Keplerian orbits space H. Their elements are identified irrespective of the values of pericentre arguments or node longitudes. We prove that distance functions on the quotient sets, introduced in Kholshevnikov et al. (Mon Not R Astron Soc 462:2275-2283, 2016), satisfy metric space axioms and discuss theoretical and practical importance of this result. Isometric embeddings of the quotient spaces into R^n, and a space of compact subsets of H with Hausdorff metric are constructed. The Euclidean representations of the orbits spaces find its applications in a problem of orbit averaging and computational algorithms specific to Euclidean space. We also explore completions of H and its quotient spaces with respect to corresponding metrics and establish a relation between elements of the extended spaces and rectilinear trajectories. Distance between an orbit and subsets of elliptic and hyperbolic orbits is calculated. This quantity provides an upper bound for the metric value in a problem of close orbits identification. Finally the invariance of the equivalence relations in H under coordinates change is discussed.

  3. Mars Observer Lecture: Mars Orbit Insertion

    NASA Technical Reports Server (NTRS)

    Dodd, Suzanne R. (Personal Name)

    1993-01-01

    The Mars Observer mission spacecraft was primarily designed for exploring Mars and the Martian environment. The Mars Observer was launched on September 25, 1992. The spacecraft was lost in the vicinity of Mars on August 21, 1993 when the spacecraft began its maneuvering sequence for Martian orbital insertion. This videotape shows a lecture by Suzanne R. Dodd, the Mission Planning Team Chief for the Mars Observer Project. Ms Dodd begins with a brief overview of the mission and the timeline from the launch to orbital insertion. Ms Dodd then reviews slides showing the trajectory of the spacecraft on its trip to Mars. Slides of the spacecraft being constructed are also shown. She then discusses the Mars orbit insertion and the events that will occur to move the spacecraft from the capture orbit into a mapping orbit. During the trip to Mars, scientists at JPL had devised a new strategy, called Power In that would allow for an earlier insertion into the mapping orbit. The talk summarizes this strategy, showing on a slide the planned transition orbits. There are shots of the Martian moon, Phobos, taken from the Viking spacecraft, as Ms Dodd explains that the trajectory will allow the orbiter to make new observations of that moon. She also explains the required steps to prepare for mapping after the spacecraft has achieved the mapping orbit around Mars. The lecture ends with a picture of Mars from the Observer on its approach to the planet.

  4. Ultrasonography of the eye and orbit.

    PubMed

    Eisenberg, H M

    1985-11-01

    The eye and orbit are excellent subjects for ultrasonic evaluation. Examination and interpretation are relatively simple procedures. The normal ultrasonic anatomy of the eye and orbit is presented. Some examples of ocular and orbital pathology are discussed also.

  5. Moonport: Transportation node in lunar orbit

    NASA Technical Reports Server (NTRS)

    1987-01-01

    An orbital transporation system between the Earth and Moon was designed. The design work focused on the requirements and configuration of an orbiting lunar base. The design utilized current Space Station technologies, but also focused on the specific requirements involved with a permanently manned, orbiting lunar station. A model of the recommended configuration was constructed. In order to analyze Moonport activity and requirements, a traffic model was designed, defining traffic between the lunar port, or Moonport and low Earth orbit. Also, a lunar base model was used to estimate requirements of the surface base on Moonport traffic and operations. A study was conducted to compare Moonport traffic and operations based in low lunar orbit and the L (sub 2) equilibrium point, behind the Moon. The study compared delta-V requirements to each location and possible payload deliveries to low Earth orbit from each location. Products of the Moonport location study included number of flights annually to Moonport, net payload delivery to low Earth orbit, and Moonport storage requirement.

  6. A Comparison of Damaging Meteoroid and Orbital Debris Fluxes in Earth Orbit

    NASA Technical Reports Server (NTRS)

    Cooke, William; Matney, Mark; Moorhead, Althea V.; Vavrin, Andrew

    2017-01-01

    Low Earth orbit is populated with a substantial amount of orbital debris, and it is usually assumed that the flux from these objects contributes to most of the hypervelocity particle risk to spacecraft in this region. The meteoroid flux is known to be dominant at very low altitudes (less than 300 km), where atmospheric drag rapidly removes debris, and at very high altitudes (beyond geostationary), where debris is practically non-existent. The vagueness of these boundaries and repeated questions from spacecraft projects have prompted this work, in which we compare the fluxes of meteoroids and orbital debris capable of producing a millimeter-deep crater in aluminum for circular orbits with altitudes ranging from the top of the atmosphere to 100,000 km. The outputs from the latest NASA debris and meteoroid models, ORDEM 3.0 and MEMR2, are combined with the modified Cour-Palais ballistic limit equation to make a realistic evaluation of the damage-capable particle fluxes, thereby establishing the relative contributions of hazardous debris and meteoroids throughout near-Earth space.

  7. Payload/orbiter contamination control requirement study

    NASA Technical Reports Server (NTRS)

    Bareiss, L. E.; Rantanen, R. O.; Ress, E. B.

    1974-01-01

    A study was conducted to determine and quantify the expected particulate and molecular on-orbit contaminant environment for selected space shuttle payloads as a result of major shuttle orbiter contamination sources. Individual payload susceptibilities to contamination are reviewed. The risk of payload degradation is identified and preliminary recommendations are provided concerning the limiting factors which may depend on operational activities associated with the payload/orbiter interface or upon independent payload functional activities. A basic computer model of the space shuttle orbiter which includes a representative payload configuration is developed. The major orbiter contamination sources, locations, and flux characteristics based upon available data have been defined and modeled.

  8. On-orbit flight control algorithm description

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Algorithms are presented for rotational and translational control of the space shuttle orbiter in the orbital mission phases, which are external tank separation, orbit insertion, on-orbit and de-orbit. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. Software functional requirements are described using block diagrams where feasible, and input--output tables, and the software implementation of each function is presented in equations and structured flow charts. Included are a glossary of all symbols used to define the requirements, and an appendix of supportive material.

  9. Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels

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

    Fabbris, G.; Meyers, D.; Okamoto, J.

    We used resonant inelastic x-ray scattering to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO 3-LaNiO 3-3×(LaAlO 3), a system with exceptionally large polarization, as a model system. Furthermore, we find that heterostructuring generates only minor changes in the Ni 3d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This also provides an explanation for the limited success of theoretical predictions based on tuning orbitalmore » energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.« less

  10. Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels

    DOE PAGES

    Fabbris, G.; Meyers, D.; Okamoto, J.; ...

    2016-09-30

    We used resonant inelastic x-ray scattering to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO 3-LaNiO 3-3×(LaAlO 3), a system with exceptionally large polarization, as a model system. Furthermore, we find that heterostructuring generates only minor changes in the Ni 3d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This also provides an explanation for the limited success of theoretical predictions based on tuning orbitalmore » energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.« less

  11. High spin systems with orbital degeneracy.

    PubMed

    Shen, Shun-Qing; Xie, X C; Zhang, F C

    2002-01-14

    High-spin systems with orbital degeneracy are studied in the large spin limit. In the absence of Hund's coupling, the classical spin model is mapped onto disconnected orbital systems with spins up and down, respectively. The ground state of the isotropic model is an orbital valence bond state where each bond is an orbital singlet with parallel spins, and neighboring bonds interact antiferromagnetically. Possible relevance to the transition metal oxides is discussed.

  12. Tethered orbital refueling study

    NASA Technical Reports Server (NTRS)

    Fester, Dale A.; Rudolph, L. Kevin; Kiefel, Erlinda R.; Abbott, Peter W.; Grossrode, Pat

    1986-01-01

    One of the major applications of the space station will be to act as a refueling depot for cryogenic-fueled space-based orbital transfer vehicles (OTV), Earth-storable fueled orbit maneuvering vehicles, and refurbishable satellite spacecraft using hydrazine. One alternative for fuel storage at the space station is a tethered orbital refueling facility (TORF), separated from the space station by a sufficient distance to induce a gravity gradient force that settles the stored fuels. The technical feasibility was examined with the primary focus on the refueling of LO2/LH2 orbital transfer vehicles. Also examined was the tethered facility on the space station. It was compared to a zero-gravity facility. A tethered refueling facility should be considered as a viable alternative to a zero-gravity facility if the zero-gravity fluid transfer technology, such as the propellant management device and no vent fill, proves to be difficult to develop with the required performance.

  13. On the lunar node resonance of the orbital plane evolution of the Earth's satellite orbits

    NASA Astrophysics Data System (ADS)

    Zhu, Ting-Lei

    2018-06-01

    This paper aims to investigate the effects of lunar node resonance on the circular medium Earth orbits (MEO). The dynamical model is established in classical Hamiltonian systems with the application of Lie transform to remove the non-resonant terms. Resonant condition, stability and phase structures are studied. The lunar node resonance occurs when the secular changing rates of the orbital node (with respect to the equator) and the lunar node (with respect to the ecliptic) form a simple integer ratio. The resonant conditions are satisfied for both inclined and equatorial orbits. The orbital plane would have long period (with typical timescales of several centuries) fluctuation due to the resonance.

  14. Geosynchronous Patrol Orbit for Space Situational Awareness

    NASA Astrophysics Data System (ADS)

    Thompson, B.; Kelecy, T.; Kubancik, T.; Flora, T.; Chylla, M.; Rose, D.

    Applying eccentricity to a geosynchronous orbit produces both longitudinal and radial motion when viewed in Earth-fixed coordinates. An interesting family of orbits emerges, useful for “neighborhood patrol” space situational awareness and other missions. The basic result is a periodic (daily), quasielliptical, closed path around a fixed region of the geosynchronous (geo) orbit belt, keeping a sensor spacecraft in relatively close vicinity to designated geo objects. The motion is similar, in some regards, to the relative motion that may be encountered during spacecraft proximity operations, but on a much larger scale. The patrol orbit does not occupy a fixed slot in the geo belt, and the east-west motion can be combined with north-south motion caused by orbital inclination, leading to even greater versatility. Some practical uses of the geo patrol orbit include space surveillance (including catalog maintenance), and general space situational awareness. The patrol orbit offers improved, diverse observation geometry for angles-only sensors, resulting in faster, more accurate orbit determination compared to simple inclined geo orbits. In this paper, we analyze the requirements for putting a spacecraft in a patrol orbit, the unique station keeping requirements to compensate for perturbations, repositioning the patrol orbit to a different location along the geo belt, maneuvering into, around, and out of the volume for proximity operations with objects within the volume, and safe end-of-life disposal requirements.

  15. Meteoroid Orbits from Observations

    NASA Astrophysics Data System (ADS)

    Campbell-Brown, Margaret

    2018-04-01

    Millions of orbits of meteoroids have been measured over the last few decades, and they comprise the largest sample of orbits of solar system bodies which exists. The orbits of these objects can shed light on the distribution and evolution of comets and asteroids in near-Earth space (e.g. Neslusan et al. 2016). If orbits can be measured at sufficiently high resolution, individual meteoroids can be traced back to their parent bodies and, in principle, even to their ejection time (Rudawska et al. 2012). Orbits can be measured with multi-station optical observations or with radar observations.The most fundamental measured quantities are the speed of the meteor and the two angles of the radiant, or point in the sky from which the meteor appears to come. There are many methods used to determine these from observations, but not all produce the most accurate results (Egal et al. 2017). These three measured quantities, along with the time and location of the observation, are sufficient to obtain an orbit (see, e.g., Clark & Wiegert 2011), but the measurements must be corrected for the deceleration of the meteoroid in the atmosphere before it was detected, the rotation of the Earth, and the gravitational attraction of the Earth (including higher order moments if great precision is necessary).Once meteor orbits have been determined, studies of the age and origin of meteor showers (Bruzzone et al., 2015), the parent bodies of sporadic sources (Pokorny et al. 2014), and the dynamics of the meteoroid complex as a whole can be constrained.Bruzzone, J. S., Brown, P., Weryk, R., Campbell-Brown, M., 2015. MNRAS 446, 1625.Clark, D., Wiegert, P., 2011. M&PS 46, 1217.Egal, A., Gural, P., Vaubaillon, J., Colas, F., Thuillot, W., 2017. Icarus 294, 43.Neslusan, L., Vaubaillon, J., Hajdukova, M., 2016. A&A 589, id.A100.Pokorny, P., Vokrouhlicky, D., Nesvorny, D., Campbell-Brown, M., Brown, P., 2014. ApJ 789, id.25.Rudawska, R., Vaubaillon, J., Atreya, P., 2012. A&A 541, id.A2

  16. Orbital Debris

    NASA Technical Reports Server (NTRS)

    Kessler, D. J. (Compiler); Su, S. Y. (Compiler)

    1985-01-01

    Earth orbital debris issues and recommended future activities are discussed. The workshop addressed the areas of environment definition, hazards to spacecraft, and space object management. It concluded that orbital debris is a potential problem for future space operations. However, before recommending any major efforts to control the environment, more data are required. The most significant required data are on the population of debris smaller than 4 cm in diameter. New damage criteria are also required. When these data are obtained, they can be combined with hypervelocity data to evaluate the hazards to future spacecraft. After these hazards are understood, then techniques to control the environment can be evaluated.

  17. Orbital Reconstruction: Patient-Specific Orbital Floor Reconstruction Using a Mirroring Technique and a Customized Titanium Mesh.

    PubMed

    Tarsitano, Achille; Badiali, Giovanni; Pizzigallo, Angelo; Marchetti, Claudio

    2016-10-01

    Enophthalmos is a severe complication of primary reconstruction of orbital floor fractures. The goal of secondary reconstruction procedures is to restore symmetrical globe positions to recover function and aesthetics. The authors propose a new method of orbital floor reconstruction using a mirroring technique and a customized titanium mesh, printed using a direct metal laser-sintering method. This reconstructive protocol involves 4 steps: mirroring of the healthy orbit at the affected site, virtual design of a patient-specific orbital floor mesh, CAM procedures for direct laser-sintering of the customized titanium mesh, and surgical insertion of the device. Using a computed tomography data set, the normal, uninjured side of the craniofacial skeleton was reflected onto the contralateral injured side, and a reconstructive orbital floor mesh was designed virtually on the mirrored orbital bone surface. The solid-to-layer files of the mesh were then manufactured using direct metal laser sintering, which resolves the shaping and bending biases inherent in the indirect method. An intraoperative navigation system ensured accuracy of the entire procedure. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography data in 7 treated patients. The technique described here appears to be a viable method to correct complex orbital floor defects needing delayed reconstruction. This study represents the first step in the development of a wider experimental protocol for orbital floor reconstruction using computer-assisted design-computer-assisted manufacturing technology.

  18. Orbital

    NASA Astrophysics Data System (ADS)

    Hanson, Robert M.

    2003-06-01

    ORBITAL requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime Plug-in, version compatible with your OS and browser (available from MDL).

  19. On Directional Measurement Representation in Orbit Determination

    DTIC Science & Technology

    2016-09-13

    representations. The three techniques are then compared experimentally for a geostationary and a low Earth orbit satellite using simulated data to evaluate their...Earth Orbit (LEO) and a Geostationary Earth Orbit (GEO) satellite. Section IV discusses the results from the numerical simulations and finally Section V... Geostationary Earth Orbit (GEO) satellite with the initial orbital parameters shown in Table 1. Different ground sites are used for the LEO and ahttps

  20. Orbital evolution of some Centaurs

    NASA Astrophysics Data System (ADS)

    Kovalenko, Nataliya; Babenko, Yuri; Churyumov, Klim

    2002-11-01

    In this work we investigated the dynamical evolution of Centaurs objects 2060 (Chiron), 5145 (Pholus), 7066 (Nessus), 8405 (Asbolus), 10199 (Chariklo), 10370 (Hylonome), and Scattered-Disk object 15874. We have carried out orbital integration of test particles with initial orbits similar to those of these objects. Calculations were produced for +/-600kyr-10Myr starting at epoch and using the implicit single sequence Everhart methods. 12 variational orbits for each of selected Centaurs also have been numerically integrated for +/-200 kyr toward the past and the future. The most probable paths were traced up to +/-1 Myr. The character of orbital elements changes and peculiarities of close approaches to giant planets are discussed.